SURGICAL INSTRUMENT WITH WIRELESS COMMUNICATION BETWEEN CONTROL UNIT AND REMOTE SENSOR

[0001] The present application is a continuation application claiming priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 14/559,224, entitled SURGICAL INSTRUMENT WITH WIRELESS COMMUNICATION BETWEEN CONTROL UNIT AND REMOTE SENSOR, filed Dec. 3, 2014, now U.S. Patent Application Publication No. 2015/0090762, which is a continuation application claiming priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 14/176,671, entitled SURGICAL INSTRUMENT WITH WIRELESS COMMUNICATION BETWEEN A CONTROL UNIT OF A ROBOTIC SYSTEM AND REMOTE SENSOR, filed Feb. 10, 2014, now U.S. Patent Application Publication No. 2014/0171966, which is a continuation application claiming priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 13/118,259, entitled SURGICAL INSTRUMENT WITH WIRELESS COMMUNICATION BETWEEN A CONTROL UNIT OF A ROBOTIC SYSTEM AND REMOTE SENSOR, filed May 27, 2011, which issued on Apr. 1, 2014 as U.S. Pat. No. 8,684,253, which is a continuation-in-part application claiming priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 11/651,807, entitled SURGICAL INSTRUMENT WITH WIRELESS COMMUNICATION BETWEEN CONTROL UNIT AND REMOTE SENSOR, filed Jan. 10, 2007, which issued on Jun. 11, 2013 as U.S. Pat. No. 8,459,520, the entire disclosures of which are hereby incorporated by reference herein.

[0002] The above listed application are related to the following U.S. Patent Applications, filed Jan. 10, 2007, which are also incorporated herein by reference in their respective entireties:

[0003] (1) U.S. patent application Ser. No. 11/651,715, entitled SURGICAL INSTRUMENT WITH WIRELESS COMMUNICATION BETWEEN CONTROL UNIT AND SENSOR TRANSPONDERS, now U.S. Pat. No. 8,652,120;

[0004] (2) U.S. patent application Ser. No. 11/651,806, entitled SURGICAL INSTRUMENT WITH ELEMENTS TO COMMUNICATE BETWEEN CONTROL UNIT AND END EFFECTOR, now U.S. Pat. No. 7,954,682;

[0005] (3) U.S. patent application Ser. No. 11/651,768, entitled PREVENTION OF CARTRIDGE REUSE IN A SURGICAL INSTRUMENT, now U.S. Pat. No. 7,721,931;

[0006] (4) U.S. patent application Ser. No. 11/651,771, entitled POST-STERILIZATION PROGRAMMING OF SURGICAL INSTRUMENTS, now U.S. Pat. No. 7,738,971;

[0007] (5) U.S. patent application Ser. No. 11/651,788, entitled INTERLOCK AND SURGICAL INSTRUMENT INCLUDING SAME, now U.S. Pat. No. 7,721,936; and

[0008] (6) U.S. patent application Ser. No. 11/651,785, entitled SURGICAL INSTRUMENT WITH ENHANCED BATTERY PERFORMANCE, now U.S. Pat. No. 7,900,805.

[0009] Known surgical staplers include an end effector that simultaneously makes a longitudinal incision in tissue and applies lines of staples on opposing sides of the incision. The end effector includes a pair of cooperating jaw members that, if the instrument is intended for endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. One of the jaw members receives a staple cartridge having at least two laterally spaced rows of staples. The other jaw member defines an anvil having staple-forming pockets aligned with the rows of staples in the cartridge. The instrument includes a plurality of reciprocating wedges which, when driven distally, pass through openings in the staple cartridge and engage drivers supporting the staples to effect the firing of the staples toward the anvil.

[0065] Various embodiments of the present invention are directed generally to a surgical instrument having at least one remote sensor transponder and means for communicating power and/or data signals to the transponder(s) from a control unit. The present invention may be used with any type of surgical instrument comprising at least one sensor transponder, such as endoscopic or laparoscopic surgical instruments, but is particularly useful for surgical instruments where some feature of the instrument, such as a free rotating joint, prevents or otherwise inhibits the use of a wired connection to the sensor(s). Before describing aspects of the system, one type of surgical instrument in which embodiments of the present invention may be used—an endoscopic stapling and cutting instrument (i.e., an endocutter)—is first described by way of illustration.

[0066] FIGS. 1 and 2 depict an endoscopic surgical instrument 10 that comprises a handle 6, a shaft 8, and an articulating end effector 12 pivotally connected to the shaft 8 at an articulation pivot 14. Correct placement and orientation of the end effector 12 may be facilitated by controls on the hand 6, including (1) a rotation knob 28 for rotating the closure tube (described in more detail below in connection with FIGS. 4-5) at a free rotating joint 29 of the shaft 8 to thereby rotate the end effector 12 and (2) an articulation control 16 to effect rotational articulation of the end effector 12 about the articulation pivot 14. In the illustrated embodiment, the end effector 12 is configured to act as an endocutter for clamping, severing and stapling tissue, although in other embodiments, different types of end effectors may be used, such as end effectors for other types of surgical instruments, such as graspers, cutters, staplers, clip appliers, access devices, drug/gene therapy devices, ultrasound, RF or laser devices, etc.

[0067] The handle 6 of the instrument 10 may include a closure trigger 18 and a firing trigger 20 for actuating the end effector 12. It will be appreciated that instruments having end effectors directed to different surgical tasks may have different numbers or types of triggers or other suitable controls for operating the end effector 12. The end effector 12 is shown separated from the handle 6 by the preferably elongate shaft 8. In one embodiment, a clinician or operator of the instrument 10 may articulate the end effector 12 relative to the shaft 8 by utilizing the articulation control 16, as described in more detail in U.S. patent application Ser. No. 11/329,020, filed Jan. 10, 2006, entitled SURGICAL INSTRUMENT HAVING AN ARTICULATING END EFFECTOR, now U.S. Pat. No. 7,670,334, which is incorporated herein by reference.

[0068] The end effector 12 includes in this example, among other things, a staple channel 22 and a pivotally translatable clamping member, such as an anvil 24, which are maintained at a spacing that assures effective stapling and severing of tissue clamped in the end effector 12. The handle 6 includes a pistol grip 26 towards which a closure trigger 18 is pivotally drawn by the clinician to cause clamping or closing of the anvil 24 toward the staple channel 22 of the end effector 12 to thereby clamp tissue positioned between the anvil 24 and channel 22. The firing trigger 20 is farther outboard of the closure trigger 18. Once the closure trigger 18 is locked in the closure position, the firing trigger 20 may rotate slightly toward the pistol grip 26 so that it can be reached by the operator using one hand. Then the operator may pivotally draw the firing trigger 20 toward the pistol grip 12 to cause the stapling and severing of clamped tissue in the end effector 12. U.S. patent application Ser. No. 11/343,573, filed Jan. 31, 2006, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH LOADING FORCE FEEDBACK, now U.S. Pat. No. 7,416,101, (the '573 application) which is incorporated herein by reference, describes various configurations for locking and unlocking the closure trigger 18. In other embodiments, different types of clamping members besides the anvil 24 could be used, such as, for example, an opposing jaw, etc.

[0069] It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician gripping the handle 6 of an instrument 10. Thus, the end effector 12 is distal with respect to the more proximal handle 6. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical” and “horizontal” are used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.

[0070] The closure trigger 18 may be actuated first. Once the clinician is satisfied with the positioning of the end effector 12, the clinician may draw back the closure trigger 18 to its fully closed, locked position proximate to the pistol grip 26. The firing trigger 20 may then be actuated. The firing trigger 20 returns to the open position (shown in FIGS. 1 and 2) when the clinician removes pressure. A release button 30 on the handle 6, and in this example, on the pistol grip 26 of the handle, when depressed may release the locked closure trigger 18.

[0071] FIG. 3 is an exploded view of the end effector 12 according to various embodiments. As shown in the illustrated embodiment, the end effector 12 may include, in addition to the previously-mentioned channel 22 and anvil 24, a cutting instrument 32, a sled 33, a staple cartridge 34 that is removably seated in the channel 22, and a helical screw shaft 36. The cutting instrument 32 may be, for example, a knife. The anvil 24 may be pivotably opened and closed at a pivot point 25 connected to the proximate end of the channel 22. The anvil 24 may also include a tab 27 at its proximate end that is inserted into a component of the mechanical closure system (described further below) to open and close the anvil 24. When the closure trigger 18 is actuated, that is, drawn in by a user of the instrument 10, the anvil 24 may pivot about the pivot point 25 into the clamped or closed position. If clamping of the end effector 12 is satisfactory, the operator may actuate the firing trigger 20, which, as explained in more detail below, causes the knife 32 and sled 33 to travel longitudinally along the channel 22, thereby cutting tissue clamped within the end effector 12. The movement of the sled 33 along the channel 22 causes the staples of the staple cartridge 34 to be driven through the severed tissue and against the closed anvil 24, which turns the staples to fasten the severed tissue. U.S. Pat. No. 6,978,921, entitled SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRING MECHANISM, which is incorporated herein by reference, provides more details about such two-stroke cutting and fastening instruments. The sled 33 may be part of the cartridge 34, such that when the knife 32 retracts following the cutting operation, the sled 33 does not retract. The channel 22 and the anvil 24 may be made of an electrically conductive material (such as metal) so that they may serve as part of the antenna that communicates with the sensor(s) in the end effector, as described further below. The cartridge 34 could be made of a nonconductive material (such as plastic) and the sensor may be connected to or disposed in the cartridge 34, as described further below.

[0072] It should be noted that although the embodiments of the instrument 10 described herein employ an end effector 12 that staples the severed tissue, in other embodiments different techniques for fastening or sealing the severed tissue may be used. For example, end effectors that use RF energy or adhesives to fasten the severed tissue may also be used. U.S. Pat. No. 5,709,680, entitled ELECTROSURGICAL HEMOSTATIC DEVICE, and U.S. Pat. No. 5,688,270, entitled ELECTROSURGICAL HEMOSTATIC DEVICE WITH RECESSED AND/OR OFFSET ELECTRODES, which are incorporated herein by reference, discloses cutting instruments that use RF energy to fasten the severed tissue. U.S. patent application Ser. No. 11/267,811, now U.S. Pat. No. 7,673,783 and U.S. patent application Ser. No. 11/267,383, now U.S. Pat. No. 7,607,557, which are also incorporated herein by reference, disclose cutting instruments that use adhesives to fasten the severed tissue. Accordingly, although the description herein refers to cutting/stapling operations and the like, it should be recognized that this is an exemplary embodiment and is not meant to be limiting. Other tissue-fastening techniques may also be used.

[0073] FIGS. 4 and 5 are exploded views and FIG. 6 is a side view of the end effector 12 and shaft 8 according to various embodiments. As shown in the illustrated embodiment, the shaft 8 may include a proximate closure tube 40 and a distal closure tube 42 pivotably linked by a pivot links 44. The distal closure tube 42 includes an opening 45 into which the tab 27 on the anvil 24 is inserted in order to open and close the anvil 24. Disposed inside the closure tubes 40, 42 may be a proximate spine tube 46. Disposed inside the proximate spine tube 46 may be a main rotational (or proximate) drive shaft 48 that communicates with a secondary (or distal) drive shaft 50 via a bevel gear assembly 52. The secondary drive shaft 50 is connected to a drive gear 54 that engages a proximate drive gear 56 of the helical screw shaft 36. The vertical bevel gear 52b may sit and pivot in an opening 57 in the distal end of the proximate spine tube 46. A distal spine tube 58 may be used to enclose the secondary drive shaft 50 and the drive gears 54, 56. Collectively, the main drive shaft 48, the secondary drive shaft 50, and the articulation assembly (e.g., the bevel gear assembly 52a-c), are sometimes referred to herein as the “main drive shaft assembly.” The closure tubes 40, 42 may be made of electrically conductive material (such as metal) so that they may serve as part of the antenna, as described further below. Components of the main drive shaft assembly (e.g., the drive shafts 48, 50) may be made of a nonconductive material (such as plastic).

[0074] A bearing 38, positioned at a distal end of the staple channel 22, receives the helical drive screw 36, allowing the helical drive screw 36 to freely rotate with respect to the channel 22. The helical screw shaft 36 may interface a threaded opening (not shown) of the knife 32 such that rotation of the shaft 36 causes the knife 32 to translate distally or proximately (depending on the direction of the rotation) through the staple channel 22. Accordingly, when the main drive shaft 48 is caused to rotate by actuation of the firing trigger 20 (as explained in more detail below), the bevel gear assembly 52a-c causes the secondary drive shaft 50 to rotate, which in turn, because of the engagement of the drive gears 54, 56, causes the helical screw shaft 36 to rotate, which causes the knife 32 to travel longitudinally along the channel 22 to cut any tissue clamped within the end effector. The sled 33 may be made of, for example, plastic, and may have a sloped distal surface. As the sled 33 traverses the channel 22, the sloped forward surface may push up or drive the staples in the staple cartridge 34 through the clamped tissue and against the anvil 24. The anvil 24 turns the staples, thereby stapling the severed tissue. When the knife 32 is retracted, the knife 32 and sled 33 may become disengaged, thereby leaving the sled 33 at the distal end of the channel 22.

[0075] According to various embodiments, as shown FIGS. 7-10, the surgical instrument may include a battery 64 in the handle 6. The illustrated embodiment provides user-feedback regarding the deployment and loading force of the cutting instrument in the end effector 12. In addition, the embodiment may use power provided by the user in retracting the firing trigger 18 to power the instrument 10 (a so-called “power assist” mode). As shown in the illustrated embodiment, the handle 6 includes exterior lower side pieces 59, 60 and exterior upper side pieces 61, 62 that fit together to form, in general, the exterior of the handle 6. The handle pieces 59-62 may be made of an electrically nonconductive material, such as plastic. A battery 64 may be provided in the pistol grip portion 26 of the handle 6. The battery 64 powers a motor 65 disposed in an upper portion of the pistol grip portion 26 of the handle 6. The battery 64 may be constructed according to any suitable construction or chemistry including, for example, a Li-ion chemistry such as LiCoO₂ or LiNiO₂, a Nickel Metal Hydride chemistry, etc. According to various embodiments, the motor 65 may be a DC brushed driving motor having a maximum rotation of, approximately, 5000 RPM to 100,000 RPM. The motor 64 may drive a 90° bevel gear assembly 66 comprising a first bevel gear 68 and a second bevel gear 70. The bevel gear assembly 66 may drive a planetary gear assembly 72. The planetary gear assembly 72 may include a pinion gear 74 connected to a drive shaft 76. The pinion gear 74 may drive a mating ring gear 78 that drives a helical gear drum 80 via a drive shaft 82. A ring 84 may be threaded on the helical gear drum 80. Thus, when the motor 65 rotates, the ring 84 is caused to travel along the helical gear drum 80 by means of the interposed bevel gear assembly 66, planetary gear assembly 72 and ring gear 78.

[0076] The handle 6 may also include a run motor sensor 110 in communication with the firing trigger 20 to detect when the firing trigger 20 has been drawn in (or “closed”) toward the pistol grip portion 26 of the handle 6 by the operator to thereby actuate the cutting/stapling operation by the end effector 12. The sensor 110 may be a proportional sensor such as, for example, a rheostat or variable resistor. When the firing trigger 20 is drawn in, the sensor 110 detects the movement, and sends an electrical signal indicative of the voltage (or power) to be supplied to the motor 65. When the sensor 110 is a variable resistor or the like, the rotation of the motor 65 may be generally proportional to the amount of movement of the firing trigger 20. That is, if the operator only draws or closes the firing trigger 20 in a little bit, the rotation of the motor 65 is relatively low. When the firing trigger 20 is fully drawn in (or in the fully closed position), the rotation of the motor 65 is at its maximum. In other words, the harder the user pulls on the firing trigger 20, the more voltage is applied to the motor 65, causing greater rates of rotation. In another embodiment, for example, the control unit (described further below) may output a PWM control signal to the motor 65 based on the input from the sensor 110 in order to control the motor 65.

[0077] The handle 6 may include a middle handle piece 104 adjacent to the upper portion of the firing trigger 20. The handle 6 also may comprise a bias spring 112 connected between posts on the middle handle piece 104 and the firing trigger 20. The bias spring 112 may bias the firing trigger 20 to its fully open position. In that way, when the operator releases the firing trigger 20, the bias spring 112 will pull the firing trigger 20 to its open position, thereby removing actuation of the sensor 110, thereby stopping rotation of the motor 65. Moreover, by virtue of the bias spring 112, any time a user closes the firing trigger 20, the user will experience resistance to the closing operation, thereby providing the user with feedback as to the amount of rotation exerted by the motor 65. Further, the operator could stop retracting the firing trigger 20 to thereby remove force from the sensor 100, to thereby stop the motor 65. As such, the user may stop the deployment of the end effector 12, thereby providing a measure of control of the cutting/fastening operation to the operator.

[0078] The distal end of the helical gear drum 80 includes a distal drive shaft 120 that drives a ring gear 122, which mates with a pinion gear 124. The pinion gear 124 is connected to the main drive shaft 48 of the main drive shaft assembly. In that way, rotation of the motor 65 causes the main drive shaft assembly to rotate, which causes actuation of the end effector 12, as described above.

[0079] The ring 84 threaded on the helical gear drum 80 may include a post 86 that is disposed within a slot 88 of a slotted arm 90. The slotted arm 90 has an opening 92 at its opposite end 94 that receives a pivot pin 96 that is connected between the handle exterior side pieces 59, 60. The pivot pin 96 is also disposed through an opening 100 in the firing trigger 20 and an opening 102 in the middle handle piece 104.

[0080] In addition, the handle 6 may include a reverse motor (or end-of-stroke sensor) 130 and a stop motor (or beginning-of-stroke) sensor 142. In various embodiments, the reverse motor sensor 130 may be a limit switch located at the distal end of the helical gear drum 80 such that the ring 84 threaded on the helical gear drum 80 contacts and trips the reverse motor sensor 130 when the ring 84 reaches the distal end of the helical gear drum 80. The reverse motor sensor 130, when activated, sends a signal to the control unit which sends a signal to the motor 65 to reverse its rotation direction, thereby withdrawing the knife 32 of the end effector 12 following the cutting operation.

[0081] The stop motor sensor 142 may be, for example, a normally-closed limit switch. In various embodiments, it may be located at the proximate end of the helical gear drum 80 so that the ring 84 trips the switch 142 when the ring 84 reaches the proximate end of the helical gear drum 80.

[0082] In operation, when an operator of the instrument 10 pulls back the firing trigger 20, the sensor 110 detects the deployment of the firing trigger 20 and sends a signal to the control unit which sends a signal to the motor 65 to cause forward rotation of the motor 65 at, for example, a rate proportional to how hard the operator pulls back the firing trigger 20. The forward rotation of the motor 65 in turn causes the ring gear 78 at the distal end of the planetary gear assembly 72 to rotate, thereby causing the helical gear drum 80 to rotate, causing the ring 84 threaded on the helical gear drum 80 to travel distally along the helical gear drum 80. The rotation of the helical gear drum 80 also drives the main drive shaft assembly as described above, which in turn causes deployment of the knife 32 in the end effector 12. That is, the knife 32 and sled 33 are caused to traverse the channel 22 longitudinally, thereby cutting tissue clamped in the end effector 12. Also, the stapling operation of the end effector 12 is caused to happen in embodiments where a stapling-type end effector is used.

[0083] By the time the cutting/stapling operation of the end effector 12 is complete, the ring 84 on the helical gear drum 80 will have reached the distal end of the helical gear drum 80, thereby causing the reverse motor sensor 130 to be tripped, which sends a signal to the control unit which sends a signal to the motor 65 to cause the motor 65 to reverse its rotation. This in turn causes the knife 32 to retract, and also causes the ring 84 on the helical gear drum 80 to move back to the proximate end of the helical gear drum 80.

[0084] The middle handle piece 104 includes a backside shoulder 106 that engages the slotted arm 90 as best shown in FIGS. 8 and 9. The middle handle piece 104 also has a forward motion stop 107 that engages the firing trigger 20. The movement of the slotted arm 90 is controlled, as explained above, by rotation of the motor 65. When the slotted arm 90 rotates CCW as the ring 84 travels from the proximate end of the helical gear drum 80 to the distal end, the middle handle piece 104 will be free to rotate CCW. Thus, as the user draws in the firing trigger 20, the firing trigger 20 will engage the forward motion stop 107 of the middle handle piece 104, causing the middle handle piece 104 to rotate CCW. Due to the backside shoulder 106 engaging the slotted arm 90, however, the middle handle piece 104 will only be able to rotate CCW as far as the slotted arm 90 permits. In that way, if the motor 65 should stop rotating for some reason, the slotted arm 90 will stop rotating, and the user will not be able to further draw in the firing trigger 20 because the middle handle piece 104 will not be free to rotate CCW due to the slotted arm 90.

[0085] Components of an exemplary closure system for closing (or clamping) the anvil 24 of the end effector 12 by retracting the closure trigger 18 are also shown in FIGS. 7-10. In the illustrated embodiment, the closure system includes a yoke 250 connected to the closure trigger 18 by a pin 251 that is inserted through aligned openings in both the closure trigger 18 and the yoke 250. A pivot pin 252, about which the closure trigger 18 pivots, is inserted through another opening in the closure trigger 18 which is offset from where the pin 251 is inserted through the closure trigger 18. Thus, retraction of the closure trigger 18 causes the upper part of the closure trigger 18, to which the yoke 250 is attached via the pin 251, to rotate CCW. The distal end of the yoke 250 is connected, via a pin 254, to a first closure bracket 256. The first closure bracket 256 connects to a second closure bracket 258. Collectively, the closure brackets 256, 258 define an opening in which the proximate end of the proximate closure tube 40 (see FIG. 4) is seated and held such that longitudinal movement of the closure brackets 256, 258 causes longitudinal motion by the proximate closure tube 40. The instrument 10 also includes a closure rod 260 disposed inside the proximate closure tube 40. The closure rod 260 may include a window 261 into which a post 263 on one of the handle exterior pieces, such as exterior lower side piece 59 in the illustrated embodiment, is disposed to fixedly connect the closure rod 260 to the handle 6. In that way, the proximate closure tube 40 is capable of moving longitudinally relative to the closure rod 260. The closure rod 260 may also include a distal collar 267 that fits into a cavity 269 in proximate spine tube 46 and is retained therein by a cap 271 (see FIG. 4).

[0086] In operation, when the yoke 250 rotates due to retraction of the closure trigger 18, the closure brackets 256, 258 cause the proximate closure tube 40 to move distally (i.e., away from the handle end of the instrument 10), which causes the distal closure tube 42 to move distally, which causes the anvil 24 to rotate about the pivot point 25 into the clamped or closed position. When the closure trigger 18 is unlocked from the locked position, the proximate closure tube 40 is caused to slide proximately, which causes the distal closure tube 42 to slide proximately, which, by virtue of the tab 27 being inserted in the window 45 of the distal closure tube 42, causes the anvil 24 to pivot about the pivot point 25 into the open or unclamped position. In that way, by retracting and locking the closure trigger 18, an operator may clamp tissue between the anvil 24 and channel 22, and may unclamp the tissue following the cutting/stapling operation by unlocking the closure trigger 18 from the locked position.

[0087] The control unit (described further below) may receive the outputs from end-of-stroke and beginning-of-stroke sensors 130, 142 and the run-motor sensor 110, and may control the motor 65 based on the inputs. For example, when an operator initially pulls the firing trigger 20 after locking the closure trigger 18, the run-motor sensor 110 is actuated. If the staple cartridge 34 is present in the end effector 12, a cartridge lockout sensor (not shown) may be closed, in which case the control unit may output a control signal to the motor 65 to cause the motor 65 to rotate in the forward direction. When the end effector 12 reaches the end of its stroke, the reverse motor sensor 130 will be activated. The control unit may receive this output from the reverse motor sensor 130 and cause the motor 65 to reverse its rotational direction. When the knife 32 is fully retracted, the stop motor sensor switch 142 is activated, causing the control unit to stop the motor 65.

[0088] In other embodiments, rather than a proportional-type sensor 110, an on-off type sensor could be used. In such embodiments, the rate of rotation of the motor 65 would not be proportional to the force applied by the operator. Rather, the motor 65 would generally rotate at a constant rate. But the operator would still experience force feedback because the firing trigger 20 is geared into the gear drive train.

[0089] The instrument 10 may include a number of sensor transponders in the end effector 12 for sensing various conditions related to the end effector 12, such as sensor transponders for determining the status of the staple cartridge 34 (or other type of cartridge depending on the type of surgical instrument), the progress of the stapler during closure and firing, etc. The sensor transponders may be passively powered by inductive signals, as described further below, although in other embodiments the transponders could be powered by a remote power source, such as a battery in the end effector 12, for example. The sensor transponder(s) could include magnetoresistive, optical, electromechanical, RFID, MEMS, motion or pressure sensors, for example. These sensor transponders may be in communication with a control unit 300, which may be housed in the handle 6 of the instrument 10, for example, as shown in FIG. 11.

[0090] As shown in FIG. 12, according to various embodiments the control unit 300 may comprise a processor 306 and one or more memory units 308. By executing instruction code stored in the memory 308, the processor 306 may control various components of the instrument 10, such as the motor 65 or a user display (not shown), based on inputs received from the various end effector sensor transponders and other sensor(s) (such as the run-motor sensor 110, the end-of-stroke sensor 130, and the beginning-of-stroke sensor 142, for example). The control unit 300 may be powered by the battery 64 during surgical use of instrument 10. The control unit 300 may comprise an inductive element 302 (e.g., a coil or antenna) to pick up wireless signals from the sensor transponders, as described in more detail below. Input signals received by the inductive element 302 acting as a receiving antenna may be demodulated by a demodulator 310 and decoded by a decoder 312. The input signals may comprise data from the sensor transponders in the end effector 12, which the processor 306 may use to control various aspects of the instrument 10.

[0091] To transmit signals to the sensor transponders, the control unit 300 may comprise an encoder 316 for encoding the signals and a modulator 318 for modulating the signals according to the modulation scheme. The inductive element 302 may act as the transmitting antenna. The control unit 300 may communicate with the sensor transponders using any suitable wireless communication protocol and any suitable frequency (e.g., an ISM band). Also, the control unit 300 may transmit signals at a different frequency range than the frequency range of the received signals from the sensor transponders. Also, although only one antenna (inductive element 302) is shown in FIG. 12, in other embodiments the control unit 300 may have separate receiving and transmitting antennas.

[0092] According to various embodiments, the control unit 300 may comprise a microcontroller, a microprocessor, a field programmable gate array (FPGA), one or more other types of integrated circuits (e.g., RF receivers and PWM controllers), and/or discrete passive components. The control units may also be embodied as system-on-chip (SoC) or a system-in-package (SIP), for example.

[0093] As shown in FIG. 11, the control unit 300 may be housed in the handle 6 of the instrument 10 and one or more of the sensor transponders 368 for the instrument 10 may be located in the end effector 12. To deliver power and/or transmit data to or from the sensor transponders 368 in the end effector 12, the inductive element 302 of the control unit 300 may be inductively coupled to a secondary inductive element (e.g., a coil) 320 positioned in the shaft 8 distally from the rotation joint 29. The secondary inductive element 320 is preferably electrically insulated from the conductive shaft 8.

[0094] The secondary inductive element 320 may be connected by an electrically conductive, insulated wire 322 to a distal inductive element (e.g., a coil) 324 located near the end effector 12, and preferably distally relative to the articulation pivot 14. The wire 322 may be made of an electrically conductive polymer and/or metal (e.g., copper) and may be sufficiently flexible so that it could pass though the articulation pivot 14 and not be damaged by articulation. The distal inductive element 324 may be inductively coupled to the sensor transponder 368 in, for example, the cartridge 34 of the end effector 12. The transponder 368, as described in more detail below, may include an antenna (or coil) for inductive coupling to the distal coil 324, a sensor and integrated control electronics for receiving and transmitting wireless communication signals.

[0095] The transponder 368 may use a portion of the power of the inductive signal received from the distal inductive element 326 to passively power the transponder 368. Once sufficiently powered by the inductive signals, the transponder 368 may receive and transmit data to the control unit 300 in the handle 6 via (i) the inductive coupling between the transponder 368 and the distal inductive element 324, (ii) the wire 322, and (iii) the inductive coupling between the secondary inductive element 320 and the control unit 300. That way, the control unit 300 may communicate with the transponder 368 in the end effector 12 without a direct wired connection through complex mechanical joints like the rotating joint 29 and/or without a direct wired connection from the shaft 8 to the end effector 12, places where it may be difficult to maintain such a wired connection. In addition, because the distances between the inductive elements (e.g., the spacing between (i) the transponder 368 and the distal inductive element 324, and (ii) the secondary inductive element 320 and the control unit 300) and fixed and known, the couplings could be optimized for inductive transfer of energy. Also, the distances could be relatively short so that relatively low power signals could be used to thereby minimize interference with other systems in the use environment of the instrument 10.

[0096] In the embodiment of FIG. 12, the inductive element 302 of the control unit 300 is located relatively near to the control unit 300. According to other embodiments, as shown in FIG. 13, the inductive element 302 of the control unit 300 may be positioned closer to the rotating joint 29 to that it is closer to the secondary inductive element 320, thereby reducing the distance of the inductive coupling in such an embodiment. Alternatively, the control unit 300 (and hence the inductive element 302) could be positioned closer to the secondary inductive element 320 to reduce the spacing.

[0097] In other embodiments, more or fewer than two inductive couplings may be used. For example, in some embodiments, the surgical instrument 10 may use a single inductive coupling between the control unit 300 in the handle 6 and the transponder 368 in the end effector 12, thereby eliminating the inductive elements 320, 324 and the wire 322. Of course, in such an embodiment, a stronger signal may be required due to the greater distance between the control unit 300 in the handle 6 and the transponder 368 in the end effector 12. Also, more than two inductive couplings could be used. For example, if the surgical instrument 10 had numerous complex mechanical joints where it would be difficult to maintain a direct wired connection, inductive couplings could be used to span each such joint. For example, inductive couplers could be used on both sides of the rotary joint 29 and both sides of the articulation pivot 14, with the inductive element 321 on the distal side of the rotary joint 29 connected by a wire 322 to the inductive element 324 of the proximate side of the articulation pivot, and a wire 323 connecting the inductive elements 325, 326 on the distal side of the articulation pivot 14 as shown in FIG. 14. In this embodiment, the inductive element 326 may communicate with the sensor transponder 368.

[0098] In addition, the transponder 368 may include a number of different sensors. For example, it may include an array of sensors. Further, the end effector 12 could include a number of sensor transponders 368 in communication with the distal inductive element 324 (and hence the control unit 300). Also, the inductive elements 320, 324 may or may not include ferrite cores. As mentioned before, they are also preferably insulated from the electrically conductive outer shaft (or frame) of the instrument 10 (e.g., the closure tubes 40, 42), and the wire 322 is also preferably insulated from the outer shaft 8.

[0099] FIG. 15 is a diagram of an end effector 12 including a transponder 368 held or embedded in the cartridge 34 at the distal end of the channel 22. The transponder 368 may be connected to the cartridge 34 by a suitable bonding material, such as epoxy. In this embodiment, the transponder 368 includes a magnetoresistive sensor. The anvil 24 also includes a permanent magnet 369 at its distal end and generally facing the transponder 368. The end effector 12 also includes a permanent magnet 370 connected to the sled 33 in this example embodiment. This allows the transponder 368 to detect both opening/closing of the end effector 12 (due to the permanent magnet 369 moving further or closer to the transponder as the anvil 24 opens and closes) and completion of the stapling/cutting operation (due to the permanent magnet 370 moving toward the transponder 368 as the sled 33 traverses the channel 22 as part of the cutting operation).

[0100] FIG. 15 also shows the staples 380 and the staple drivers 382 of the staple cartridge 34. As explained previously, according to various embodiments, when the sled 33 traverses the channel 22, the sled 33 drives the staple drivers 382 which drive the staples 380 into the severed tissue held in the end effector 12, the staples 380 being formed against the anvil 24. As noted above, such a surgical cutting and fastening instrument is but one type of surgical instrument in which the present invention may be advantageously employed. Various embodiments of the present invention may be used in any type of surgical instrument having one or more sensor transponders.

[0101] In the embodiments described above, the battery 64 powers (at least partially) the firing operation of the instrument 10. As such, the instrument may be a so-called “power-assist” device. More details and additional embodiments of power-assist devices are described in the '573 application, which is incorporated herein. It should be recognized, however, that the instrument 10 need not be a power-assist device and that this is merely an example of a type of device that may utilize aspects of the present invention. For example, the instrument 10 may include a user display (such as a LCD or LED display) that is powered by the battery 64 and controlled by the control unit 300. Data from the sensor transponders 368 in the end effector 12 may be displayed on such a display.

[0102] In another embodiment, the shaft 8 of the instrument 10, including for example, the proximate closure tube 40 and the distal closure tube 42, may collectively serve as part of an antenna for the control unit 300 by radiating signals to the sensor transponder 368 and receiving radiated signals from the sensor transponder 368. That way, signals to and from the remote sensor in the end effector 12 may be transmitted via the shaft 8 of the instrument 10.

[0103] The proximate closure tube 40 may be grounded at its proximate end by the exterior lower and upper side pieces 59-62, which may be made of a nonelectrically conductive material, such as plastic. The drive shaft assembly components (including the main drive shaft 48 and secondary drive shaft 50) inside the proximate and distal closure tubes 40, 42 may also be made of a nonelectrically conductive material, such as plastic. Further, components of end effector 12 (such as the anvil 24 and the channel 22) may be electrically coupled to (or in direct or indirect electrical contact with) the distal closure tube 42 such that they may also serve as part of the antenna. Further, the sensor transponder 368 could be positioned such that it is electrically insulated from the components of the shaft 8 and end effector 12 serving as the antenna. For example, the sensor transponder 368 may be positioned in the cartridge 34, which may be made of a nonelectrically conductive material, such as plastic. Because the distal end of the shaft 8 (such as the distal end of the distal closure tube 42) and the portions of the end effector 12 serving as the antenna may be relatively close in distance to the sensor 368, the power for the transmitted signals may be held at low levels, thereby minimizing or reducing interference with other systems in the use environment of the instrument 10.

[0104] In such an embodiment, as shown in FIG. 16, the control unit 300 may be electrically coupled to the shaft 8 of the instrument 10, such as to the proximate closure tube 40, by a conductive link 400 (e.g., a wire). Portions of the outer shaft 8, such as the closure tubes 40, 42, may therefore act as part of an antenna for the control unit 300 by radiating signals to the sensor 368 and receiving radiated signals from the sensor 368. Input signals received by the control unit 300 may be demodulated by the demodulator 310 and decoded by the decoder 312 (see FIG. 12). The input signals may comprise data from the sensors 368 in the end effector 12, which the processor 306 may use to control various aspects of the instrument 10, such as the motor 65 or a user display.

[0105] To transmit data signals to or from the sensors 368 in the end effector 12, the link 400 may connect the control unit 300 to components of the shaft 8 of the instrument 10, such as the proximate closure tube 40, which may be electrically connected to the distal closure tube 42. The distal closure tube 42 is preferably electrically insulated from the remote sensor 368, which may be positioned in the plastic cartridge 34 (see FIG. 3). As mentioned before, components of the end effector 12, such as the channel 22 and the anvil 24 (see FIG. 3), may be conductive and in electrical contact with the distal closure tube 42 such that they, too, may serve as part of the antenna.

[0106] With the shaft 8 acting as the antenna for the control unit 300, the control unit 300 can communicate with the sensor 368 in the end effector 12 without a direct wired connection. In addition, because the distances between shaft 8 and the remote sensor 368 is fixed and known, the power levels could be optimized for low levels to thereby minimize interference with other systems in the use environment of the instrument 10. The sensor 368 may include communication circuitry for radiating signals to the control unit 300 and for receiving signals from the control unit 300, as described above. The communication circuitry may be integrated with the sensor 368.

[0107] In another embodiment, the components of the shaft 8 and/or the end effector 12 may serve as an antenna for the remote sensor 368. In such an embodiment, the remote sensor 368 is electrically connected to the shaft (such as to distal closure tube 42, which may be electrically connected to the proximate closure tube 40) and the control unit 300 is insulated from the shaft 8. For example, the sensor 368 could be connected to a conductive component of the end effector 12 (such as the channel 22), which in turn may be connected to conductive components of the shaft (e.g., the closure tubes 40, 42). Alternatively, the end effector 12 may include a wire (not shown) that connects the remote sensor 368 the distal closure tube 42.

[0108] Typically, surgical instruments, such as the instrument 10, are cleaned and sterilized prior to use. In one sterilization technique, the instrument 10 is placed in a closed and sealed container 280, such as a plastic or TYVEK container or bag, as shown in FIGS. 17 and 18. The container and the instrument are then placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation kills bacteria on the instrument 10 and in the container 280. The sterilized instrument 10 can then be stored in the sterile container 280. The sealed, sterile container 280 keeps the instrument 10 sterile until it is opened in a medical facility or some other use environment. Instead of radiation, other means of sterilizing the instrument 10 may be used, such as ethylene oxide or steam.

[0109] When radiation, such as gamma radiation, is used to sterilize the instrument 10, components of the control unit 300, particularly the memory 308 and the processor 306, may be damaged and become unstable. Thus, according to various embodiments of the present invention, the control unit 300 may be programmed after packaging and sterilization of the instrument 10.

[0110] As shown in FIG. 17, a remote programming device 320, which may be a handheld device, may be brought into wireless communication with the control unit 300. The remote programming device 320 may emit wireless signals that are received by the control unit 300 to program the control unit 300 and to power the control unit 300 during the programming operation. That way, the battery 64 does not need to power the control unit 300 during the programming operation. According to various embodiments, the programming code downloaded to the control unit 300 could be of relatively small size, such as 1 MB or less, so that a communications protocol with a relatively low data transmission rate could be used if desired. Also, the remote programming unit 320 could be brought into close physical proximity with the surgical instrument 10 so that a low power signal could be used.

[0111] Referring back to FIG. 19, the control unit 300 may comprise an inductive coil 402 to pick up wireless signals from a remote programming device 320. A portion of the received signal may be used by a power circuit 404 to power the control unit 300 when it is not being powered by the battery 64.

[0112] Input signals received by the coil 402 acting as a receiving antenna may be demodulated by a demodulator 410 and decoded by a decoder 412. The input signals may comprise programming instructions (e.g., code), which may be stored in a non-volatile memory portion of the memory 308. The processor 306 may execute the code when the instrument 10 is in operation. For example, the code may cause the processor 306 to output control signals to various sub-systems of the instrument 10, such as the motor 65, based on data received from the sensors 368.

[0113] The control unit 300 may also comprise a non-volatile memory unit 414 that comprises boot sequence code for execution by the processor 306. When the control unit 300 receives enough power from the signals from the remote control unit 320 during the post-sterilization programming operation, the processor 306 may first execute the boot sequence code (“boot loader”) 414, which may load the processor 306 with an operating system.

[0114] The control unit 300 may also send signals back to the remote programming unit 320, such as acknowledgement and handshake signals, for example. The control unit 300 may comprise an encoder 416 for encoding the signals to then be sent to the programming device 320 and a modulator 418 for modulating the signals according to the modulation scheme. The coil 402 may act as the transmitting antenna. The control unit 300 and the remote programming device 320 may communicate using any suitable wireless communication protocol (e.g., Bluetooth) and any suitable frequency (e.g., an ISM band). Also, the control unit 300 may transmit signals at a different frequency range than the frequency range of the received signals from the remote programming unit 320.

[0115] FIG. 20 is a simplified diagram of the remote programming device 320 according to various embodiments of the present invention. As shown in FIG. 20, the remote programming unit 320 may comprise a main control board 230 and a boosted antenna board 232. The main control board 230 may comprise a controller 234, a power module 236, and a memory 238. The memory 238 may stored the operating instructions for the controller 234 as well as the programming instructions to be transmitted to the control unit 300 of the surgical instrument 10. The power module 236 may provide a stable DC voltage for the components of the remote programming device 320 from an internal battery (not shown) or an external AC or DC power source (not shown).

[0116] The boosted antenna board 232 may comprise a coupler circuit 240 that is in communication with the controller 234 via an I²C bus, for example. The coupler circuit 240 may communicate with the control unit 300 of the surgical instrument via an antenna 244. The coupler circuit 240 may handle the modulating/demodulating and encoding/decoding operations for transmissions with the control unit. According to other embodiments, the remote programming device 320 could have a discrete modulator, demodulator, encoder and decoder. As shown in FIG. 20, the boost antenna board 232 may also comprise a transmitting power amp 246, a matching circuit 248 for the antenna 244, and a filter/amplifier 249 for receiving signals.

[0117] According to other embodiments, as shown in FIG. 20, the remote programming device could be in communication with a computer device 460, such as a PC or a laptop, via a USB and/or RS232 interface, for example. In such a configuration, a memory of the computing device 460 may store the programming instructions to be transmitted to the control unit 300. In another embodiment, the computing device 460 could be configured with a wireless transmission system to transmit the programming instructions to the control unit 300.

[0118] In addition, according to other embodiments, rather than using inductive coupling between the control unit 300 and the remote programming device 320, capacitively coupling could be used. In such an embodiment, the control unit 300 could have a plate instead of a coil, as could the remote programming unit 320.

[0119] In another embodiment, rather than using a wireless communication link between the control unit 300 and the remote programming device 320, the programming device 320 may be physically connected to the control unit 300 while the instrument 10 is in its sterile container 280 in such a way that the instrument 10 remains sterilized. FIG. 21 is a diagram of a packaged instrument 10 according to such an embodiment. As shown in FIG. 22, the handle 6 of the instrument 10 may include an external connection interface 470. The container 280 may further comprise a connection interface 472 that mates with the external connection interface 470 of the instrument 10 when the instrument 10 is packaged in the container 280. The programming device 320 may include an external connection interface (not shown) that may connect to the connection interface 472 at the exterior of the container 280 to thereby provide a wired connection between the programming device 320 and the external connection interface 470 of the instrument 10.

[0120] In one embodiment, the present invention is directed to a surgical instrument, such as an endoscopic or laparoscopic instrument. The surgical instrument may comprise a shaft having a distal end connected to an end effector and a handle connected to a proximate end of the shaft. The handle may comprise a control unit (e.g., a microcontroller) that is in communication with a first sensor element. Further, the surgical instrument may comprise a rotational joint for rotating the shaft. In such a case, the surgical instrument may comprise the first element located in the shaft distally from the rotational joint. The first element may be coupled to the control unit either by a wired or wireless electrical connection. A second element may be located in the end effector and may be coupled to the first element by a wireless electrical connection. The first and second elements may be connected and/or coupled by a wired or a wireless electrical connection.

[0121] The control unit may communicate with the second sensor element in the end effector without a direct wired electrical connection through complex mechanical joints like a rotating joint or articulating pivot where it may be difficult to maintain such a wired electrical connection. In addition, because the distances between the inductive elements may be fixed and known, the couplings between the first and second sensor elements may be optimized for inductive and/or electromagnetic transfer of energy. Also, the distances may be relatively short so that relatively low power signals may be used to minimize interference with other systems in the use environment of the instrument.

[0122] In another embodiment of the present invention, the electrically conductive shaft of the surgical instrument may serve as an antenna for the control unit to wirelessly communicate signals to and from one or more sensor elements. For example, one or more sensor elements may be located on or disposed in a nonconductive component of the end effector, such as a plastic cartridge, thereby insulating the sensor element from conductive components of the end effector and the shaft. In addition, the control unit in the handle may be electrically coupled to the shaft. In that way, the shaft and/or the end effector may serve as an antenna for the control unit to radiate signals from the control unit to the one or more sensor elements and/or receive radiated echo response signals from the one or more sensor elements. Such a design is particularly useful in surgical instruments having complex mechanical joints (such as rotary joints) and articulating pivots, which make it difficult to use a direct wired electrical connection between the sensor elements and the control unit for communicating electrical signals therebetween.

[0123] Various embodiments of the present invention are directed generally to a surgical instrument comprising one or more sensor elements to sense the location, type, presence and/or status of various components of interest disposed on the surgical instrument. In one embodiment, the present invention is directed generally to a surgical instrument having one or more sensor elements to sense the location, type, presence and/or status of various components of interest disposed in an end effector portion of the surgical instrument. These components of interest may comprise, for example, a sled, a staple cartridge, a cutting instrument or any other component that may be disposed on the surgical instrument and more particularly disposed in the end effector portion thereof. Although the present invention may be used with any type of surgical instrument such as endoscopic or laparoscopic surgical instruments, it is particularly useful for surgical instruments comprising one or more free rotating joints or an articulation pivots that make it difficult to use wired electrical connections to the one or more passive and/or active sensor elements.

[0124] The one or more sensor elements may be passive or active sensor elements adapted to communicate with a control unit in any suitable manner. In various embodiments, some of the sensor elements may not be supplied power over a wired electrical connection and as described herein, neither the passive nor the active sensor elements may comprise an internal power supply. The sensor elements may operate using the power provided by the minute electrical current induced in the sensor element itself or an antenna coupled to the sensor element by an incoming radio frequency (RF) interrogation signal transmitted by the control unit. This means that the antenna and/or the sensor element itself may be designed to collect power from the incoming interrogation signal and also to transmit an outbound backscatter signal in response thereto. The lack of an onboard power supply means that the sensor elements may have a relatively small form factor. In embodiments comprising a passive sensor element RF interrogation signals may be received by the passive sensor element wirelessly over a predetermined channel. The incident electromagnetic radiation associated with the RF interrogation signals is then scattered or reflected back to the interrogating source such as the control unit. Thus, the passive sensor element signals by backscattering the carrier of the RF interrogation signal from the control unit. In embodiments comprising an active sensor element, on the other hand, just enough power may be received from the RF interrogation signals to cause the active sensor element to power up and transmit an analog or digital signal back to the control unit in response in response to the RF interrogation signal. The control unit may be referred to as a reader, interrogator or the like.

[0125] In one embodiment, the status of a component (e.g., sled, staple cartridge, cutting instrument) located in the end effector portion of the surgical instrument may be determined through the use of a system comprising passive and/or active sensor elements coupled to a control unit. The passive sensor elements may be formed of or comprise passive hardware elements such as resistive, inductive and/or capacitive elements or any combination thereof. The active sensor elements may be formed of or comprise active hardware elements. These active hardware elements may be integrated and/or discrete circuit elements or any combination thereof. Examples of integrated and/or discrete hardware elements are described herein below.

[0126] In one embodiment, the system may comprise a control unit coupled to a primary sensor element (primary element) disposed at a distal end of a shaft of the surgical instrument prior to an articulation pivot (as described below) and a secondary sensor element (secondary element) disposed on a component of interest in an end effector portion of the surgical instrument located subsequent to the articulation pivot (e.g., on a sled as described below). Rather than transmitting continuous power to the secondary element over a wired electrical connection, the primary element wirelessly interrogates or illuminates the secondary element by transmitting an electromagnetic pulse signal over a channel at a predetermined frequency, duration and repetition rate. When the interrogation pulse signal is incident upon, i.e., strikes or illuminates, the secondary element, it generated an echo response signal. The echo response signal is a reflection of the electromagnetic energy incident upon the secondary element. After transmitting the interrogation signal, the primary element listens for the echo response signal reflected from the secondary element and couples the echo response signal to the control unit in a suitable form for subsequent processing. The echo response signal may be of the same frequency as the interrogation pulse or some harmonic frequency thereof. The amount of reflected energy in the echo response signal depends upon the material, shape and size of the secondary element. The amount of reflected energy in the echo response signal also depends upon the distance between the primary element and the secondary element. Therefore, the material, shape and size of the secondary element as well as the relative distance between the primary and secondary elements may be selected to generate a unique echo response signal that is indicative of a desired measurement associated with the component of interest coupled to the secondary element. For example, unique echo response signals may indicate the location, type, presence and/or status of various components and sub-components disposed in the surgical instrument. Especially, the various components and sub-components disposed in the end effector portion of the surgical instrument subsequent to a freely rotating joint or articulation pivot that may make it difficult or impractical to provide a wired electrical connection between the primary and the secondary elements. The echo response signals also may be used to determine the distance between the primary and secondary elements. In this manner, the secondary element may be made integral with or may be attached to a component of interest and the echo response signal may provide information associated with the component of interest. This arrangement may eliminate the need to transmit or provide power to the secondary element over a wired connection and may be a cost effective solution to providing various additional passive and/or active sensor elements in the surgical instrument. Before describing aspects of the system, one type of surgical instrument in which embodiments of the present invention may be used—an endoscopic stapling and cutting instrument (i.e., an endocutter)—is first described by way of illustration.

[0127] FIGS. 23 and 24 depict an endoscopic surgical instrument 2010 that comprises a handle 2006, a shaft 2008, and an articulating end effector 2012 pivotally connected to the shaft 2008 at an articulation pivot 2014. Correct placement and orientation of the end effector 2012 may be facilitated by controls on the hand 2006, including (1) a rotation knob 2028 for rotating the closure tube (described in more detail below in connection with FIGS. 26-27) at a free rotating joint 2029 of the shaft 2008 to thereby rotate the end effector 2012 and (2) an articulation control 2016 to effect rotational articulation of the end effector 2012 about the articulation pivot 2014. In the illustrated embodiment, the end effector 2012 is configured to act as an endocutter for clamping, severing and stapling tissue, although in other embodiments, different types of end effectors may be used, such as end effectors for other types of surgical instruments, such as graspers, cutters, staplers, clip appliers, access devices, drug/gene therapy devices, ultrasound, RF or laser devices, etc.

[0128] The handle 2006 of the instrument 2010 may include a closure trigger 2018 and a firing trigger 2020 for actuating the end effector 2012. It will be appreciated that instruments having end effectors directed to different surgical tasks may have different numbers or types of triggers or other suitable controls for operating the end effector 2012. The end effector 2012 is shown separated from the handle 2006 by the preferably elongate shaft 2008. The handle may comprise a control unit 2300 (described below) in communication with a first element 2021 by way of an electrical connection 2023. The electrical connection 2023 may be a wired electrical connection such as an electrically conductive insulated wire or may be a wireless electrical connection. The electrically conductive insulated wire may be made of an electrically conductive polymer and/or metal (e.g., copper) and may be sufficiently flexible so that it could pass through the articulation control 2016, the rotation knob 2028, the free rotating joint 2029 and other components in the handle 2006 of the instrument 2010 without being damaged by rotation. The first element 2021 may be disposed at a distal end of the shaft 2008 prior to the articulation pivot 2014. A second element 2035 (shown in FIG. 25 below) may be disposed in the articulating end effector 2012 and is in wireless communication with the first element 2021. The operation of the first and second elements 2021, 2023 and the control unit 2300 is described below. In one embodiment, a clinician or operator of the instrument 2010 may articulate the end effector 2012 relative to the shaft 2008 by utilizing the articulation control 2016, as described in more detail in U.S. patent application Ser. No. 11/329,020, filed Jan. 10, 2006, entitled SURGICAL INSTRUMENT HAVING AN ARTICULATING END EFFECTOR, now U.S. Pat. No. 7,670,334, which is incorporated herein by reference.

[0129] The end effector 2012 includes in this example, among other things, a staple channel 2022 and a pivotally translatable clamping member, such as an anvil 2024, which are maintained at a spacing that assures effective stapling and severing of tissue clamped in the end effector 2012. The handle 2006 includes a pistol grip 2026 towards which a closure trigger 2018 is pivotally drawn by the clinician to cause clamping or closing of the anvil 2024 toward the staple channel 2022 of the end effector 2012 to thereby clamp tissue positioned between the anvil 2024 and channel 2022. The firing trigger 2020 is farther outboard of the closure trigger 2018. Once the closure trigger 2018 is locked in the closure position, the firing trigger 2020 may rotate slightly toward the pistol grip 2026 so that it can be reached by the operator using one hand. Then the operator may pivotally draw the firing trigger 2020 toward the pistol grip 2026 to cause the stapling and severing of clamped tissue in the end effector 2012. The '573 application describes various configurations for locking and unlocking the closure trigger 2018. In other embodiments, different types of clamping members besides the anvil 2024 could be used, such as, for example, an opposing jaw, etc.

[0130] It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician gripping the handle 2006 of the instrument 2010. Thus, the end effector 2012 is distal with respect to the more proximal handle 2006. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical” and “horizontal” are used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.

[0131] The closure trigger 2018 may be actuated first. Once the clinician is satisfied with the positioning of the end effector 2012, the clinician may draw back the closure trigger 2018 to its fully closed, locked position proximate to the pistol grip 2026. The firing trigger 2020 may then be actuated. When the clinician removes pressure from the firing trigger 2020, it returns to the open position (shown in FIGS. 23 and 24). A release button 2030 on the handle 2006, and in this example, on the pistol grip 2026 of the handle, when depressed may release the locked closure trigger 2018.

[0132] FIG. 25 is an exploded view of the end effector 2012 according to various embodiments. As shown in the illustrated embodiment, the end effector 2012 may include, in addition to the previously-mentioned channel 2022 and anvil 2024, a cutting instrument 2032, a sled 2033, a staple cartridge 2034 that is removably seated in the channel 2022, and a helical screw shaft 2036. The second element 2035 may be coupled or formed integrally with a component of interest. The cutting instrument 2032 may be, for example, a knife. The anvil 2024 may be pivotably opened and closed at a pivot point 2025 connected to the proximate end of the channel 2022. The anvil 2024 may also include a tab 2027 at its proximate end that is inserted into a component of the mechanical closure system (described further below) to open and close the anvil 2024. When the closure trigger 2018 is actuated, that is, drawn in by a user of the instrument 2010, the anvil 2024 may pivot about the pivot point 2025 into the clamped or closed position. If clamping of the end effector 2012 is satisfactory, the operator may actuate the firing trigger 2020, which, as explained in more detail below, causes the knife 2032 and sled 2033 to travel longitudinally along the channel 2022, thereby cutting tissue clamped within the end effector 2012. The movement of the sled 2033 along the channel 2022 causes the staples of the staple cartridge 2034 to be driven through the severed tissue and against the closed anvil 2024, which turns the staples to fasten the severed tissue. U.S. Pat. No. 6,978,921, entitled SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRING MECHANISM, which is incorporated herein by reference, provides more details about such two-stroke cutting and fastening instruments. The sled 2033, which may comprise the second element 2035, may be part of the cartridge 2034, such that when the knife 2032 retracts following the cutting operation, the sled 2033 and the second element 2035 do not retract. The cartridge 2034 could be made of a nonconductive material (such as plastic). In one embodiment, the second element 2035 may be connected to or disposed in the cartridge 2034, for example. In the illustrated embodiment, the second element 2035 may be attached to the sled 2033 in any suitable manner and on any suitable portion thereof. In other embodiments, the second element 2035 may be embedded in the sled 2033 or otherwise integrally formed (e.g., co-molded) with the sled 2033. Accordingly, the location of the sled 2033 may be determined by detecting the location of the second element 2035. The second element 2035 may be formed of various materials in various sizes and shapes and may be located at certain predetermined distances from the first element 2021 to enable the control unit 2300 to ascertain the type, presence and status of the staple cartridge 2034.

[0133] It should be noted that although the embodiments of the instrument 2010 described herein employ an end effector 2012 that staples the severed tissue, in other embodiments different techniques for fastening or sealing the severed tissue may be used. For example, end effectors that use RF energy or adhesives to fasten the severed tissue may also be used. U.S. Pat. No. 5,709,680, entitled ELECTROSURGICAL HEMOSTATIC DEVICE, and U.S. Pat. No. 5,688,270, entitled ELECTROSURGICAL HEMOSTATIC DEVICE WITH RECESSED AND/OR OFFSET ELECTRODES, which are incorporated herein by reference, discloses cutting instruments that use RF energy to fasten the severed tissue. U.S. patent application Ser. No. 11/267,811, now U.S. Pat. No. 7,673,783 and U.S. patent application Ser. No. 11/267,383, now U.S. Pat. No. 7,607,557, which are also incorporated herein by reference, disclose cutting instruments that use adhesives to fasten the severed tissue. Accordingly, although the description herein refers to cutting/stapling operations and the like, it should be recognized that this is an exemplary embodiment and is not meant to be limiting. Other tissue-fastening techniques may also be used.

[0134] FIGS. 26 and 27 are exploded views and FIG. 28 is a side view of the end effector 2012 and shaft 2008 according to various embodiments. As shown in the illustrated embodiment, the shaft 2008 may include a proximate closure tube 2040 and a distal closure tube 2042 pivotably linked by a pivot links 2044. The distal closure tube 2042 includes an opening 2045 into which the tab 2027 on the anvil 2024 is inserted in order to open and close the anvil 2024. Disposed inside the closure tubes 2040, 2042 may be a proximate spine tube 2046. Disposed inside the proximate spine tube 2046 may be a main rotational (or proximate) drive shaft 2048 that communicates with a secondary (or distal) drive shaft 2050 via a bevel gear assembly 2052. In the illustrated embodiment, the first element 2021 may be a coil disposed about the proximate spine tube 2046 (e.g., as shown in FIGS. 26 and 27). In a wired electrical connection configuration, the first element 2021 may be connected to the control unit 2300 by way of the wired electrical connection 2023, which may comprise lengths of wire forming the coil. The lengths of wire may be provided along the proximate spine tube 2046 to connect to the control unit 2300. In a wireless electrical connection configuration, a wire is not necessary and the electrical connection 2023 to the control unit 2300 is a wireless electrical connection. In one embodiment, the first element 2021 may be contained within the proximate spine tube 2046 (e.g., as shown in FIG. 28). In either case, the first element 2021 is electrically isolated from the proximate spine tube 2046.

[0135] The secondary drive shaft 2050 is connected to a drive gear 2054 that engages a proximate drive gear 2056 of the helical screw shaft 2036. The vertical bevel gear 2052b may sit and pivot in an opening 2057 in the distal end of the proximate spine tube 2046. A distal spine tube 2058 may be used to enclose the secondary drive shaft 2050 and the drive gears 2054, 2056. Collectively, the main drive shaft 2048, the secondary drive shaft 2050, and the articulation assembly (e.g., the bevel gear assembly 2052a-c), are sometimes referred to herein as the “main drive shaft assembly.” Components of the main drive shaft assembly (e.g., the drive shafts 2048, 2050) may be made of a nonconductive material (such as plastic).

[0136] A bearing 2038, positioned at a distal end of the staple channel 2022, receives the helical drive screw 2036, allowing the helical drive screw 2036 to freely rotate with respect to the channel 2022. The helical screw shaft 2036 may interface a threaded opening (not shown) of the knife 2032 such that rotation of the shaft 2036 causes the knife 2032 to translate distally or proximately (depending on the direction of the rotation) through the staple channel 2022. Accordingly, when the main drive shaft 2048 is caused to rotate by actuation of the firing trigger 2020 (as explained in more detail below), the bevel gear assembly 2052a-c causes the secondary drive shaft 2050 to rotate, which in turn, because of the engagement of the drive gears 2054, 2056, causes the helical screw shaft 2036 to rotate, which causes the knife 2032 to travel longitudinally along the channel 2022 to cut any tissue clamped within the end effector. The sled 2033 may be made of, for example, plastic, and may have a sloped distal surface. As previously discussed, the second element 2035 may be attached to the sled 2033 in any suitable manner to determine the status, location and type of the sled 2033 and/or the staple cartridge 2034. As the sled 2033 traverses the channel 2022, the sloped forward surface may push up or drive the staples in the staple cartridge 2034 through the clamped tissue and against the anvil 2024. The anvil 2024 turns the staples, thereby stapling the severed tissue. When the knife 2032 is retracted, the knife 2032 and sled 2033 may become disengaged, thereby leaving the sled 2033 at the distal end of the channel 2022.

[0137] According to various embodiments, as shown FIGS. 29-32, the surgical instrument may include a battery 2064 in the handle 2006. The illustrated embodiment provides user-feedback regarding the deployment and loading force of the cutting instrument in the end effector 2012. In addition, the embodiment may use power provided by the user in retracting the firing trigger 2018 to power the instrument 2010 (a so-called “power assist” mode). As shown in the illustrated embodiment, the handle 2006 includes exterior lower side pieces 2059, 2060 and exterior upper side pieces 2061, 2062 that fit together to form, in general, the exterior of the handle 2006. The handle pieces 2059-2062 may be made of an electrically nonconductive material, such as plastic. A battery 2064 may be provided in the pistol grip portion 2026 of the handle 2006. The battery 2064 powers a motor 2065 disposed in an upper portion of the pistol grip portion 2026 of the handle 2006. The battery 2064 may be constructed according to any suitable construction or chemistry including, for example, a Li-ion chemistry such as LiCoO₂ or LiNiO₂, a Nickel Metal Hydride chemistry, etc. According to various embodiments, the motor 2065 may be a DC brushed driving motor having a maximum rotation of, approximately, 5000 to 100,000 RPM. The motor 2065 may drive a 90° bevel gear assembly 2066 comprising a first bevel gear 2068 and a second bevel gear 2070. The bevel gear assembly 2066 may drive a planetary gear assembly 2072. The planetary gear assembly 2072 may include a pinion gear 2074 connected to a drive shaft 2076. The pinion gear 2074 may drive a mating ring gear 2078 that drives a helical gear drum 2080 via a drive shaft 20082. A ring 2084 may be threaded on the helical gear drum 2080. Thus, when the motor 2065 rotates, the ring 2084 is caused to travel along the helical gear drum 2080 by means of the interposed bevel gear assembly 2066, planetary gear assembly 2072 and ring gear 2078.

[0138] The handle 2006 may also include a run motor sensor 2110 in communication with the firing trigger 2020 to detect when the firing trigger 2020 has been drawn in (or “closed”) toward the pistol grip portion 2026 of the handle 2006 by the operator to thereby actuate the cutting/stapling operation by the end effector 2012. The sensor 2110 may be a proportional sensor such as, for example, a rheostat or variable resistor. When the firing trigger 2020 is drawn in, the sensor 2110 detects the movement, and sends an electrical signal indicative of the voltage (or power) to be supplied to the motor 2065. When the sensor 2110 is a variable resistor or the like, the rotation of the motor 2065 may be generally proportional to the amount of movement of the firing trigger 2020. That is, if the operator only draws or closes the firing trigger 2020 in a little bit, the rotation of the motor 2065 is relatively low. When the firing trigger 2020 is fully drawn in (or in the fully closed position), the rotation of the motor 2065 is at its maximum. In other words, the harder the user pulls on the firing trigger 2020, the more voltage is applied to the motor 2065, causing greater rates of rotation.

[0139] The handle 2006 may include a middle handle piece 2104 adjacent to the upper portion of the firing trigger 2020. The handle 2006 also may comprise a bias spring 2112 connected between posts on the middle handle piece 2104 and the firing trigger 2020. The bias spring 2112 may bias the firing trigger 2020 to its fully open position. In that way, when the operator releases the firing trigger 2020, the bias spring 2112 will pull the firing trigger 2020 to its open position, thereby removing actuation of the sensor 2110, thereby stopping rotation of the motor 2065. Moreover, by virtue of the bias spring 2112, any time a user closes the firing trigger 2020, the user will experience resistance to the closing operation, thereby providing the user with feedback as to the amount of rotation exerted by the motor 2065. Further, the operator could stop retracting the firing trigger 2020 to thereby remove force from the sensor 2110, to thereby stop the motor 2065. As such, the user may stop the deployment of the end effector 2012, thereby providing a measure of control of the cutting/fastening operation to the operator.

[0140] The distal end of the helical gear drum 2080 includes a distal drive shaft 2120 that drives a ring gear 2122, which mates with a pinion gear 2124. The pinion gear 2124 is connected to the main drive shaft 2048 of the main drive shaft assembly. In that way, rotation of the motor 2065 causes the main drive shaft assembly to rotate, which causes actuation of the end effector 2012, as described above.

[0141] The ring 2084 threaded on the helical gear drum 2080 may include a post 2086 that is disposed within a slot 2088 of a slotted arm 2090. The slotted arm 2090 has an opening 2092 at its opposite end 2094 that receives a pivot pin 2096 that is connected between the handle exterior side pieces 2059, 2060. The pivot pin 2096 is also disposed through an opening 2100 in the firing trigger 2020 and an opening 2102 in the middle handle piece 2104.

[0142] In addition, the handle 2006 may include a reverse motor (or end-of-stroke sensor) 2130 and a stop motor (or beginning-of-stroke) sensor 2142. In various embodiments, the reverse motor sensor 2130 may be a limit switch located at the distal end of the helical gear drum 2080 such that the ring 2084 threaded on the helical gear drum 2080 contacts and trips the reverse motor sensor 2130 when the ring 2084 reaches the distal end of the helical gear drum 2080. The reverse motor sensor 2130, when activated, sends a signal to the control unit which sends a signal to the motor 2065 to reverse its rotation direction, thereby withdrawing the knife 2032 of the end effector 2012 following the cutting operation.

[0143] The stop motor sensor 2142 may be, for example, a normally-closed limit switch. In various embodiments, it may be located at the proximate end of the helical gear drum 2080 so that the ring 2084 trips the switch 2142 when the ring 2084 reaches the proximate end of the helical gear drum 2080.

[0144] The handle 2006 also may comprise the control unit 2300. The control unit 2300 may be powered through the battery 2064 with the addition of a conditioning circuit (not shown). The control unit 2300 is coupled to the first element 2021 by an electrical connection 2023. As previously discussed, the electrical connection 2023 may be a wired electrical connection or a wireless electrical connection.

[0145] In operation, when an operator of the instrument 2010 pulls back the firing trigger 2020, the sensor 2110 detects the deployment of the firing trigger 2020 and sends a signal to the control unit which sends a signal to the motor 2065 to cause forward rotation of the motor 2065 at, for example, a rate proportional to how hard the operator pulls back the firing trigger 2020. The forward rotation of the motor 2065 in turn causes the ring gear 2078 at the distal end of the planetary gear assembly 2072 to rotate, thereby causing the helical gear drum 2080 to rotate, causing the ring 2084 threaded on the helical gear drum 2080 to travel distally along the helical gear drum 2080. The rotation of the helical gear drum 2080 also drives the main drive shaft assembly as described above, which in turn causes deployment of the knife 2032 in the end effector 2012. That is, the knife 2032 and the sled 2033 are caused to traverse the channel 2022 longitudinally, thereby cutting tissue clamped in the end effector 2012. Also, the stapling operation of the end effector 2012 is caused to happen in embodiments where a stapling-type end effector is used.

[0146] By the time the cutting/stapling operation of the end effector 2012 is complete, the ring 2084 on the helical gear drum 2080 will have reached the distal end of the helical gear drum 2080, thereby causing the reverse motor sensor 2130 to be tripped, which sends a signal to the control unit which sends a signal to the motor 2065 to cause the motor 2065 to reverse its rotation. This in turn causes the knife 2032 to retract, and also causes the ring 2084 on the helical gear drum 2080 to move back to the proximate end of the helical gear drum 2080.

[0147] The middle handle piece 2104 includes a backside shoulder 2106 that engages the slotted arm 2090 as best shown in FIGS. 30 and 31. The middle handle piece 2104 also has a forward motion stop 2107 that engages the firing trigger 2020. The movement of the slotted arm 2090 is controlled, as explained above, by rotation of the motor 2065. When the slotted arm 2090 rotates CCW as the ring 2084 travels from the proximate end of the helical gear drum 2080 to the distal end, the middle handle piece 2104 will be free to rotate CCW. Thus, as the user draws in the firing trigger 2020, the firing trigger 2020 will engage the forward motion stop 2107 of the middle handle piece 2104, causing the middle handle piece 2104 to rotate CCW. Due to the backside shoulder 2106 engaging the slotted arm 2090, however, the middle handle piece 2104 will only be able to rotate CCW as far as the slotted arm 2090 permits. In that way, if the motor 2065 should stop rotating for some reason, the slotted arm 2090 will stop rotating, and the user will not be able to further draw in the firing trigger 2020 because the middle handle piece 2104 will not be free to rotate CCW due to the slotted arm 2090.

[0148] Components of an exemplary closure system for closing (or clamping) the anvil 2024 of the end effector 2012 by retracting the closure trigger 2018 are also shown in FIGS. 29-32. In the illustrated embodiment, the closure system includes a yoke 2250 connected to the closure trigger 2018 by a pin 2251 that is inserted through aligned openings in both the closure trigger 2018 and the yoke 2250. A pivot pin 2252, about which the closure trigger 2018 pivots, is inserted through another opening in the closure trigger 2018 which is offset from where the pin 2251 is inserted through the closure trigger 2018. Thus, retraction of the closure trigger 2018 causes the upper part of the closure trigger 2018, to which the yoke 2250 is attached via the pin 2251, to rotate CCW. The distal end of the yoke 2250 is connected, via a pin 2254, to a first closure bracket 2256. The first closure bracket 2256 connects to a second closure bracket 2258. Collectively, the closure brackets 2256, 2258 define an opening in which the proximate end of the proximate closure tube 2040 (FIG. 26) is seated and held such that longitudinal movement of the closure brackets 2256, 2258 causes longitudinal motion by the proximate closure tube 2040. The instrument 2010 also includes a closure rod 2260 disposed inside the proximate closure tube 2040. The closure rod 2260 may include a window 2261 into which a post 2263 on one of the handle exterior pieces, such as exterior lower side piece 2059 in the illustrated embodiment, is disposed to fixedly connect the closure rod 2260 to the handle 2006. In that way, the proximate closure tube 2040 is capable of moving longitudinally relative to the closure rod 2260. The closure rod 2260 may also include a distal collar 2267 that fits into a cavity 2269 in proximate spine tube 2046 and is retained therein by a cap 2271 (FIG. 26).

[0149] In operation, when the yoke 2250 rotates due to retraction of the closure trigger 2018, the closure brackets 2256, 2258 cause the proximate closure tube 2040 to move distally (i.e., away from the handle end of the instrument 2010), which causes the distal closure tube 2042 to move distally, which causes the anvil 2024 to rotate about the pivot point 2025 into the clamped or closed position. When the closure trigger 2018 is unlocked from the locked position, the proximate closure tube 2040 is caused to slide proximately, which causes the distal closure tube 2042 to slide proximately, which, by virtue of the tab 2027 being inserted in the window 2045 of the distal closure tube 2042, causes the anvil 2024 to pivot about the pivot point 2025 into the open or unclamped position. In that way, by retracting and locking the closure trigger 2018, an operator may clamp tissue between the anvil 2024 and channel 2022, and may unclamp the tissue following the cutting/stapling operation by unlocking the closure trigger 2018 from the locked position.

[0150] The control unit 2300 (described further below) may receive the outputs from end-of-stroke and beginning-of-stroke sensors 2130, 2142 and the run-motor sensor 2110, and may control the motor 2065 based on the inputs. For example, when an operator initially pulls the firing trigger 2020 after locking the closure trigger 2018, the run-motor sensor 2110 is actuated. If the staple cartridge 2034 is present in the end effector 2012, a cartridge lockout sensor (not shown) may be closed, in which case the control unit may output a control signal to the motor 2065 to cause the motor 2065 to rotate in the forward direction. When the end effector 2012 reaches the end of its stroke, the reverse motor sensor 2130 will be activated. The control unit may receive this output from the reverse motor sensor 2130 and cause the motor 2065 to reverse its rotational direction. When the knife 2032 is fully retracted, the stop motor sensor switch 2142 is activated, causing the control unit to stop the motor 2065.

[0151] In other embodiments, rather than a proportional-type sensor 2110, an on-off type sensor may be used. In such embodiments, the rate of rotation of the motor 2065 would not be proportional to the force applied by the operator. Rather, the motor 2065 would generally rotate at a constant rate. But the operator would still experience force feedback because the firing trigger 2020 is geared into the gear drive train.

[0152] The instrument 2010 may include a number of sensor elements in the end effector 2012 for sensing various conditions related to the end effector 2012, such as sensor elements for determining the status of the staple cartridge 2034 (or other type of cartridge depending on the type of surgical instrument), the progress of the stapler during closure and firing, etc. The sensor elements may be passively powered by inductively coupled signals, as described in commonly assigned U.S. patent application Ser. No. 11/651,715, entitled SURGICAL INSTRUMENT WITH WIRELESS COMMUNICATION BETWEEN CONTROL UNIT AND SENSOR TRANSPONDERS, now U.S. Pat. No. 8,652,120, which is incorporated herein by reference. In other embodiments, the sensor elements reflect or scatter incident electromagnetic energy or power up in response to the interrogation signal and transmit echo response pulses or signals that may be coupled back to the control unit 2300 for processing. In other embodiments, the sensor elements may be powered by the minute electrical current induced in the sensor element itself or an antenna coupled to the sensor element by the incoming incident electromagnetic energy (e.g., the RF carrier of the interrogation signal) transmitted by the control unit 2300. These sensor elements may comprise any arrangement of electrical conductors to transmit, receive, amplify, encode, scatter and/or reflect electromagnetic energy waves of any suitable predetermined frequency (e.g., wavelength [λ]), having a suitable predetermined pulse width that may be transmitted over a suitable predetermined time period. The passive sensor elements may comprise any suitable arrangement of resistive, inductive, and/or capacitive elements. The active sensor elements may comprise semiconductors such as transistors, integrated circuits, processors, amplifiers and/or any combination of these active elements. For succinctness the passive and/or active sensor elements are referred to hereinafter as the first element 2021 and the second element 2035. The first element 2021 may be in wired or wireless communication with the control unit 2300, which, as previously discussed, may be housed in the handle 2006 of the instrument 2010, for example, as shown below in FIG. 33. The first element 2021 is in wireless communication with the second element 2035.

[0153] FIG. 33 illustrates a schematic block diagram of one embodiment of the control unit 2300. According to various embodiments, the control unit 2300 may comprise a processor 2306 and one or more memory units 2308. By executing instruction code stored in the memory 2308, the processor 2306 may control various components of the instrument 2010, such as the motor 2065 or a user display (not shown), based on inputs received from the one or more end effector sensor element(s) and/or other sensor elements located throughout the instrument 2010 (such as the run-motor sensor 2110, the end-of-stroke sensor 2130, and the beginning-of-stroke sensor 2142, for example). The control unit 2300 may be powered by the battery 2064 during surgical use of the instrument 2010. The control unit 2300 may be coupled to the first element 2021 over the electrical connection 2023 and may communicate with the second element 2035, as described in more detail below. The control unit 2300 may comprise a transmitter 2320 and a receiver 2322. The first element 2021 may be coupled to the transmitter 2320 to transmit an output interrogation signal or may be coupled to the receiver 2322 to receive an echo response signal in accordance with the operation of a switch 2324.

[0154] The switch 2324 may operate under the control of the processor 2306, the transmitter 2320 or the receiver 2322 or any combination thereof to place the control unit 2300 either in transmitter or receiver mode. In transmitter mode, the switch 2324 couples the first element 2021 to the transmitter 2320 and thus the first element 2021 acts as a transmitting antenna. An encoder 2316 encodes the output interrogation signal to be transmitted, which is then modulated by a modulator 2318. An oscillator 2326 coupled to the modulator 2318 sets the operating frequency for the output signal to be transmitted. In receiver mode, the switch 2324 couples the first element 2021 to the receiver 2322. Accordingly, the first element 2021 acts as a receiving antenna and receives input signals from the other sensor elements (e.g., the second element 2035). The received input signals may be demodulated by a demodulator 2310 and decoded by a decoder 2312. The input signals may comprise echo response signals from one or more of the sensor elements (e.g., the second element 2035). The echo response signals may comprise information associated with the location, type, presence and/or status of various components located in the end effector 2012 or in other location in the instrument 2010. The echo signals, for example, may comprise signals reflected by the second element 2035, which may be attached to the sled 2033, the staple cartridge 2034 or any other component located in the end effector 2012 or may be located on any component of interest on any portion of the instrument 2010. The echo signal data reflected from the second element 2035 may be used by the processor 2306 to control various aspects of the instrument 2010.

[0155] To transmit an output signal from the first element 2021 to the second element 2035, the control unit 2300 may employ the encoder 2316 for encoding the output signals and the modulator 2318 for modulating the output signals according to a predetermined modulation scheme. As previously discussed, in transmitter mode, the first element 2021 is coupled to the transmitter 2320 through the switch 2324 and acts as a transmitting antenna. The encoder 2316 may comprise a timing unit to generate timing pulses at a predetermined suitable pulse repetition frequency. These timing pulses may be applied to the modulator 2318 to trigger the transmitter at precise and regularly occurring instants of time. Thus, in one embodiment, the modulator 2318 may produce rectangular pulses of known pulse duration to switch the oscillator 2326 on and off. In accordance with the modulation scheme, the oscillator 2326 produces short duration pulses of a predetermined power and frequency (or wavelength λ) set by the oscillator 2326. The pulse repetition frequency may be determined by the encoder 2312 and the pulse duration may be determined by the modulator 2318. The switch 2324 under control of the control unit 2300 automatically connects the transmitter 2320 to the first element 2021 for the duration of each output pulse. In transmission mode, the first element 2021 radiates the transmitter 2320 output pulse signal and picks up or detects the reflected echo signals for application to the receiver 2322. In receiver mode, the switch 2324 connects the first element 2021 to the receiver 2322 for the intervals between transmission pulses. The receiver 2322 receives echo signals of the transmitted pulse output signals that may be reflected from one or more sensor elements located on the instrument such as the second element 2035 attached to the sled 2033. The receiver 2322 amplifies the echo signals and presents them to the demodulator 2310 in suitable form. Subsequently, the demodulated echo signals are provided to the decoder 2312 where they are correlated with the transmitted output pulse signals to determine the location, type, presence and/or status of various components located in the end effector 2012. In addition, the distance between the first and second elements 2021, 2035 may be determined

[0156] The control unit 2300 may communicate with the first element 2021 using any suitable wired or wireless communication protocol and any suitable frequency (e.g., an ISM band). The control unit 2300 may transmit output pulse signals in various frequency ranges. Although in the illustrated embodiment, only the first element 2021 is shown to perform the transmission and reception functions, in other embodiments the control unit 2300 may comprise separate receiving and transmitting elements, for example.

[0157] According to various embodiments, the control unit 2300 may be implemented using integrated and/or discrete hardware elements, software elements, or a combination of both. Examples of integrated hardware elements may include processors, microprocessors, microcontrollers, integrated circuits, application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate arrays (FPGA), logic gates, registers, semiconductor devices, chips, microchips, chip sets, microcontroller, system-on-chip (SoC) or system-in-package (SIP). Examples of discrete hardware elements may include circuits, circuit elements (e.g., logic gates, field effect transistors, bipolar transistors, resistors, capacitors, inductors, relay and so forth). In other embodiments, the control unit 2300 may be embodied as a hybrid circuit comprising discrete and integrated circuit elements or components on one or more substrates. In various embodiments, the control unit 2300 may provide a digital (e.g., on/off, high/low) output and/or an analog output to a motor control unit. The motor control unit also may be embodied using elements and/or components similar to the control unit 2300. The motor control unit may be used to control the motor 2065 in response to the radiated echo response signals from the one or more passive and/or active sensor elements.

[0158] Referring back to FIGS. 23-28, in one embodiment, the first element 2021 may be an inductive element (e.g., a first coil) coupled to the control unit 2300 by the wired electrical connection 2023. The wired electrical connection 2023 may be an electrically conductive insulated wire. The second element 2035 also may be an inductive element (e.g., a second coil) embedded, integrally formed with or otherwise attached to the sled 2033. The second element 2035 is wirelessly coupled to the first element 2021. The first element 2021 is preferably electrically insulated from the conductive shaft 2008. The second element 2035 is preferably electrically insulated from the sled 2033 and other components located in the staple cartridge 2034 and/or the staple channel 2022. The second element 2035 receives the output pulse signal transmitted by the first element 2021 and reflects or scatters the electromagnetic energy in the form of an echo signal. By varying the material, size, shape and location of the second element 2035 relative to the first element 2021, the control unit 2300 can determine the location, type, presence and/or status of various components located in the end effector 2012 by decoding the echo signals reflected therefrom.

[0159] FIG. 34 is a schematic diagram 2400 illustrating the operation of one embodiment of the control unit 2300 in conjunction with the first and second elements 2021, 2035. The following description also references FIG. 33. The first element 2021 is coupled to the control unit 2300 by a channel, e.g., the electrical connection 2023. The electrical connection 2023 may be a wired or wireless channel. As previously discussed, the first element 2021 wirelessly interrogates or illuminates the second element 2035 by transmitting an interrogation signal in the form of one or more interrogation pulses 2402. The interrogation pulses 2402 may be of a suitable predetermined frequency f as may be determined by the oscillator 2326. The interrogation pulses 2402 may have a predetermined pulse width PW as may be determined by the modulator 2318 and may be transmitted at a pulse repetition rate T as may be determined by the encoder 2316. The transmitted interrogation pulses 2402 that are incident upon (e.g., strike or illuminate) the second element 2035 is reflected or scattered by the second element 2035 in the form of echo response pulses 2404. The echo response pulses 2404 are electromagnetic energy reflections of the interrogation pulses 2402 incident upon the second element 2021, but much weaker in signal strength. After transmitting the interrogation pulses 2402, the first element 2021 listens for the echo response pulses 2404 and couples the echo response pulses 2402 to the control unit 2300 in a suitable form. The demodulator 2310 receives the weak echo response pulses 2404 and amplifies and demodulates them. The decoder 2312 and the processor 2306 process the received echo response pulses 2404 to extract information therefrom. The processor 2306 (or other logic) may be programmed to ascertain various properties associated with the end effector 2012 and components in accordance with the received echo response pulses 2404.

[0160] The frequency f, PW and T of the echo response pulses 2404 may be the same as the interrogation pulses 2402. In various embodiments, the frequency f, PW and T of the echo response pulses 2404 may be different than the interrogation pulses 2402. In one embodiment, the frequency f, for example, of the echo response pulses 2404 may be a harmonic frequency of the interrogation pulse 2402 frequency. The amount of reflected electromagnetic energy in the echo response pulses 2404 depends upon the material, shape and size of the second element 2035. The amount of reflected electromagnetic energy in the echo response pulses 2404 also depends upon the distance D between the first element 2021 and the second element 2035.

[0161] The material that the second element 2035 is formed of may determine the amount of reflected energy. For example, a metal object will reflect more energy than an object of the same size and shape made of wood, plastic, etc. In general, the better the electrical conductive properties of the material the greater is the reflection. The shape of the second element 2035 also may determine how the energy is reflected or scattered. For example, if the second element 2035 has a flat side facing the first element 2021, the second element 2035 may reflect more energy back towards the first element 2021. A circular object may reflect or scatter the energy in the various directions normal to the surface struck by the incident electromagnetic energy and an object with irregularities will scatter the incident electromagnetic energy more randomly. The size of the second element 2021 also may determine the amount of reflected energy. For example, a larger second element 2035 will reflect more energy than a smaller second element 2035 of the same material and shape and at the same distance D from the first element 2021. It will be appreciated that the second element 2035 should have a certain minimum size relative to the wavelength (λ) of the radiated electromagnetic energy of the interrogation pulses 2402 to produce practical reflected echo response pulses 2404. For example, the size of the second element 2035 may be equal to or greater than about a quarter of the wavelength (λ/4) of the electromagnetic energy of the interrogation pulses 2402. The wavelength λ of the transmitted interrogation pulses 2402 is related to the frequency f in accordance with the equation: λ=c/f; where c is the speed of light and f is the signal frequency. Therefore, to detect small objects the wavelength λ must be small and thus the frequency f must be high. Any suitable predetermined frequency f may be selected to accommodate the size of the second element 2035 to be detected. Accordingly, the size of the second element 2035 may be selected to be greater than or equal to λ/4 (or c/4f), for example, once the interrogation pulse 2402 frequency is determined. As previously discussed, the amount of energy reflected by the second element 2035 also depends on the distance D between the first element 2021 and the second element 2035.

[0162] Accordingly, the material, shape and size of the second element 2035 and the relative distance D between it and the first element 2021 may be selected to generate unique echo response pulses 2404 that may be indicative of a desired measurement associated with the second element 2035. For example, unique echo response pulses 2404 may indicate the location, type, presence and/or status of various components and/or sub-components disposed on the surgical instrument 2010. Especially the various components and sub-components disposed in the end effector 2012 portion of the surgical instrument 2010 subsequent to the articulation pivot 2014. The echo response pulses 2404 also may be used to determine the distance D between the first element 2021 and the second element 2035. In this manner, by integrating the second element 2035 or attaching it to a components of interest, such as the sled 2033, the echo response pulses 2404 may be processed by the control unit 2300 to extract and provide information associated with the component of interest, such as the location, type, presence and/or status of the sled 2033, the staple cartridge 2034, and so on. This arrangement may eliminate the need to transmit or provide power over a wired connection to the second element 2035 and may be a cost effective solution to providing various sensor elements on the surgical instrument 2010.

[0163] In one embodiment, where the second element 2035 is an active sensor element, as previously discussed, the first element 2021 wirelessly interrogates or illuminates the second element 2035 by transmitting an interrogation signal in the form of one or more interrogation pulses 2402. The electromagnetic energy in the interrogation pulses 2402 are coupled by the sensor element 2035 and serve to power-up the sensor element 2035. Once powered-up, the sensor element 2035 transmits the echo response pulses 2404 back to the control unit 2300.

[0164] In one embodiment, the status of the staple cartridge 2034 and the location of the sled 2033 may be determined by transmitting the interrogation pulse 2402 and listening for an echo response pulse 2404. As previously discussed, the first and second elements 2021, 2035 may be passive sensors or electromagnetic elements (which may comprise resistive, inductive and capacitive elements or any combination thereof). In one embodiment, the first element 2021 may be an inductance in the form of a primary coil located at the distal end of the shaft 2008 (as shown in FIGS. 23, 24, 26-28). The second element 2035 may be an inductive element in the form of a secondary coil located in the sled 2033 (as shown in FIGS. 25, 27, 28). The first element 2021 “pings” or transmits interrogation pulses 2402. The echo response pulses 2404 reflected by the second element 2035 may be indicative of the presence of the sled 2033 in the staple channel 2022, its distance from the first element 2021 or its location longitudinally along the staple channel 2022. In this manner, the instrument 2010 can determine the presence or status of the staple cartridge 2034 or the sled 2033 in the end effector 2012 or the longitudinal location of the sled 2033 along the staple channel 2022. This information may be used to determine the loaded status of the staple cartridge 2034, for example. Further the second element 2035 may be formed of different materials, in different shapes or sizes to produce a unique echo response pulse 2404 that is indicative of the instrument 2010 type or presence of the staple cartridge 2034 within the end effector 2012. This eliminates the need to include any powered memory or sensor elements in the end effector 2012 to electronically determine the type, presence or status of the staple cartridge 2034 in the end effector 2012.

[0165] In another embodiment, the second element 2035 may be attached to the sled 2033 and the echo response pulse 2404 may be used to determine whether the sled 2033 is located in a first position at the proximal end of the staple channel 2022 or a second position at the distal end of the staple channel 2022 or in any intermediate positions therebetween. The control unit 2300 may be determine the position of the sled 2033 based on the elapsed time between transmitting the interrogation pulse 2402 and receiving the echo response pulse 2404. If the sled 2033 is in the first position the echo response pulse 2404 is received sooner than if the sled 2033 was located at the second position or any position therebetween. For example, as the sled 2033 moves longitudinally along the staple channel 2022 the response time of the received echo response pulse 2404 relative to the transmitted interrogation pulse 2402 increases. This information may be used by the control unit 2300 to determine the intermediate location of the sled 2033 in the channel 2022 and provide some measure of control of the cutting/fastening operation, such as inhibiting the cutting/fastening operation if the sled 2033, or other component, is not in a predetermined location.

[0166] In yet another embodiment, the control unit 2300 may provide some measure of control of the cutting/fastening operation based on whether or not an echo response pulse 2404 is received within a predetermined time period. For example, if an echo response pulse 2404 is received within the predetermined period, the control unit 2300 determines that the sled 2033 in located in the proximate end on the staple channel 2022. In contrast, if the no echo response pulse 2404 is received within the predetermined period, the control unit 2300 determines that the sled 2033 has moved away from the proximate end to the distal end of the staple channel 2022 (e.g., the instrument has been fired). In this manner, if no echo response pulse 2404 is received, the control unit 2300 may determine either that the staple cartridge 2034 has been fired and, therefore, the sled 2033 has moved away longitudinally from the proximate end of the staple channel 2022 or that there is no staple cartridge 2034 loaded and, therefore, prevents the instrument 2010 (e.g., a surgical stapler) from firing.

[0167] Although the first element 2021 is shown disposed at one end of the elongate shaft 2008 near the articulation pivot 2014, the first element 2021 may be disposed anywhere along the elongate shaft 2008 and/or in the handle 2006 in suitable wireless or wired communication with the second element 2035.

[0168] FIG. 35 illustrates one embodiment of the surgical instrument 2010 comprising the first element 2021 located in the free rotating joint 2029 portion of the shaft 2008. The following description also references FIGS. 25, 27, 28 and 34. The first element 2021 is coupled to the control unit 2300 via the electrical connection 2023. Additional elements may be employed, for example, when the surgical instrument 2010 has numerous complex mechanical joints and where it would be difficult to maintain a direct wired connection. In such cases, inductive couplings may be used to span each such joint. For example, inductive couplers may be used on both sides of the rotary joint 2029 and both sides of the articulation pivot 2014, with an inductive element on the distal side of the rotary joint 2029 connected by an electrical connection to another inductive element on the proximate side of the articulation pivot 2014. Accordingly, a third element 2328 and a fourth element 2330 may be disposed on the shaft 2008. These elements 2328, 2330 may disposed anywhere along the shaft 2008. The third element 2328 may be disposed on the proximal end of the shaft 2008 just prior to the articulation control 2016. The fourth element 2330 may be disposed on the distal end of the shaft 2008 just prior to the articulation pivot 2014. The third and fourth elements 2328, 2330 may be coupled by an electrical connection 2332, which may be a wired or a wireless electrical connection. The second element 2035 is disposed or attached to a component of interest in the end effector 2012. The third element 2328 is wirelessly coupled to the first element 2021 and receives interrogation pulses 2402 therefrom. The third element 2328 transmits the interrogation pulse 2402 along the electrical connection 2332 to the fourth element 2330. The fourth element 2330 wirelessly couples the interrogation pulse 2402 to the second element 2035. The echo response pulses 2404 are transmitted back to the first element 2021 in reverse order. For example, the echo response pulse 2404 is wirelessly coupled to the fourth element 2330, is relayed to the third element 2328 via the electrical connection 2332 and is then wirelessly coupled to the first element 2021. Similarly to the first and second elements 2021, 2035, the third and fourth elements 2328, 2330 may be formed of passive and/or active sensor elements (e.g., resistive, inductance, capacitive and/or semiconductor elements). In one embodiment, the third and fourth elements 2328, 2330 may be passive coils formed of various materials and in various shapes and sizes or may comprise semiconductor elements such as transistors to operate in active mode.

[0169] FIG. 36 illustrates one embodiment of the surgical instrument 2010 comprising sensor elements disposed at various locations on the shaft. For example, the first element 2021 may be disposed on the proximate end of the shaft 2008 just prior to the articulation control 2016. The first element 2021 is wirelessly coupled to the control unit 2300 via wireless electrical connection 2023. The third element 2328 and the fourth element 2330 are disposed along the shaft 2008 subsequent to the articulation control 2016 and prior to the articulation pivot 2014. The third element 2328 may be disposed on the proximate end of the shaft 2008 subsequent to the articulation control 2016 and the fourth element 2330 may be disposed on the distal end of the elongate shaft 2008 prior to the articulation pivot 2014. The third and fourth elements 2328, 2330 are coupled by the electrical connection 2332, which may be a wired or a wireless electrical connection. As previously discussed, the second element 2035 may be disposed on a component of interest located in the end effector 2012. The third element 2328 is wirelessly coupled to the first element 2021 and receives the interrogation pulses 2402 therefrom. The third element 2328 transmits the interrogation pulse 2402 along the electrical connection 2332 to the fourth element 2330. The fourth element 2330 wirelessly couples the interrogation pulse 2402 to the second element 2035. The echo response pulses 2404 are transmitted back to the first element 2021 in reverse order. For example, the echo response pulse 2404 is wirelessly coupled to the fourth element 2330, is relayed to the third element 2328 via the electrical connection 2332 and is wirelessly coupled to the first element 2021 thereafter.

[0170] FIG. 37 illustrates one embodiment of the instrument 2010 where the shaft serves as part of the antenna for the control unit 2300. Accordingly, the shaft 2008 of the instrument 2010, including for example, the proximate closure tube 2040 and the distal closure tube 2042, may collectively serve as part of an antenna for the control unit 2300 by radiating the interrogation pulses 2402 to the second element 2035 and receiving the echo response pulses 2404 reflected from the second element 2035. That way, signals to and from the control unit 2300 and the second element 2035 disposed in the end effector 2012 may be transmitted via the shaft 2008 of the instrument 2010.

[0171] The proximate closure tube 2040 may be grounded at its proximate end by the exterior lower and upper side pieces 2059-2062, which may be made of a nonelectrically conductive material, such as plastic. The drive shaft assembly components (including the main drive shaft 2048 and secondary drive shaft 2050) inside the proximate and distal closure tubes 2040, 2042 may also be made of a nonelectrically conductive material, such as plastic. Further, components of the end effector 2012 (such as the anvil 2024 and the channel 2022) may be electrically coupled to (or in direct or indirect electrical contact with) the distal closure tube 2042 such that they may also serve as part of the antenna. Further, the second element 2035 may be positioned such that it is electrically insulated from the components of the shaft 2008 and the end effector 2012 serving as the antenna. For example, the second element 2035 may be positioned in the cartridge 2034, which may be made of a nonelectrically conductive material, such as plastic. Because the distal end of the shaft 2008 (such as the distal end of the distal closure tube 2042) and the portions of the end effector 2012 serving as the antenna may be relatively close in distance to the second element 2035, the power for the transmitted signals may be held at low levels, thereby minimizing or reducing interference with other systems in the use environment of the instrument 2010.

[0172] In such an embodiment, the control unit 2300 may be electrically coupled to the shaft 2008 of the instrument 2010, such as to the proximate closure tube 2040, by an electrically conductive connection 2410 (e.g., a wire). Portions of the outer shaft 2008, such as the closure tubes 2040, 2042, may therefore act as part of an antenna for the control unit 2300 by radiating signals in the form of interrogation pulses 2402 to the second element 2035 and receiving radiated signals in the form of echo response pulses 2404 from the second element 2035. The echo response pulses 2404 received by the control unit 2300 may be demodulated by the demodulator 2310 and decoded by the decoder 2312 as previously discussed. The echo response pulses 2404 may comprise information from the second element 2035 such as, the location, type, presence and/or status of various components disposed on the end effector 2012 portion of the instrument 2010, which the processor 2306 may use to control various aspects of the instrument 2010, such as the motor 2065 or a user display.

[0173] To transmit data signals to or from the second element 2035 in the end effector 2012, the electrical connection 2410 may connect the control unit 2300 to components of the shaft 2008 of the instrument 2010, such as the proximate closure tube 2040, which may be electrically connected to the distal closure tube 2042. The distal closure tube 2042 is preferably electrically insulated from the remote sensor 2368, which may be positioned in the plastic cartridge 2034. As mentioned before, components of the end effector 2012, such as the channel 2022 and the anvil 2024, may be conductive and in electrical contact with the distal closure tube 2042 such that they, too, may serve as part of the antenna.

[0174] With the shaft 2008 acting as the antenna for the control unit 2300, the control unit 2300 can communicate with the second element 2035 in the end effector 2012 without a direct wired connection. In addition, because the distances between shaft 2008 and the second element 2035 is fixed and known, the power levels could be optimized for low levels to thereby minimize interference with other systems in the use environment of the instrument 2010.

[0175] Although throughout this description, the second element 2035 is shown disposed in the articulating end effector 2012, the second element 2035 may be disposed in any suitable location on the instruments 2010 while maintaining wireless communication with the first element 2021 (and/or the shaft 2008) at least on one portion of the transmission or reception cycle. The second element 2035 also may be coupled to any component within the staple cartridge 2034.

[0176] The control unit 2300 may communicate with any of the first 2021, second 2035, third 2328 and fourth 2330 elements and additional elements through complex mechanical joints like the rotating joint 2029 without a direct wired connection, but rather through a wireless connection where it may be difficult to maintain a wired connection. In addition, because the distances between the first, second, third, fourth 2021, 2035, 2328, 2330 elements, and any additional elements and/or any combination thereof, may be fixed and known the couplings between these elements 2021, 2035, 2328, 2330 may be optimized for efficient inductive transfer of electromagnetic energy. Also, these distances may be relatively short so that relatively low power signals may be used and minimize interference with other systems in the use environment of the instrument 2010.

[0177] In other embodiments, more or fewer sensor elements may be inductively, electromagnetically and/or otherwise coupled. For example, in some embodiments, the control unit 2300 may comprise the first element 2021 formed integrally therewith. The first element 2021 in the handle 2006 and the second element 2035 in the end effector 2012 can communicate directly without the third and fourth elements 2328, 2330. Of course, in such an embodiment, a stronger signal may be required due to the greater distance between the control unit 2300 in the handle 2006 and the second element 2035 in the end effector 2012.

[0178] In the embodiments described above, the battery 2064 (FIG. 29) powers (at least partially) the firing operation of the instrument 2010. As such, the instrument 2010 may be a so-called “power-assist” device. More details and additional embodiments of power-assist devices are described in the '573 application, which is incorporated herein by reference. It should be recognized, however, that the instrument 2010 need not be a power-assist device and that this is merely an example of a type of device that may utilize aspects of the present invention. For example, the instrument 2010 may include a user display (such as a LCD or LED display) that is powered by the battery 2064 and controlled by the control unit 2300. Data from the sensor transponders 2368 in the end effector 2012 may be displayed on such a display.

[0179] FIGS. 38 and 39 depict a surgical cutting and fastening instrument 3010 according to various embodiments of the present invention. The illustrated embodiment is an endoscopic instrument and, in general, the embodiments of the instrument 3010 described herein are endoscopic surgical cutting and fastening instruments. It should be noted, however, that according to other embodiments of the present invention, the instrument may be a non-endoscopic surgical cutting and fastening instrument, such as a laparoscopic instrument.

[0180] The surgical instrument 3010 depicted in FIGS. 38 and 39 comprises a handle 3012, a shaft 3014, and an articulating end effector 3016 pivotally connected to the shaft 3014 at an articulation pivot 3018. Correct placement and orientation of the end effector 3016 may be facilitated by controls on the handle 3012, including (1) a rotation knob 3017 for rotating the closure tube (described in more detail below in connection with FIGS. 41-42) at a free rotating joint 3019 of the shaft 3014 to thereby rotate the end effector 3016 and (2) an articulation control 3020 to effect rotational articulation of the end effector 3016 about the articulation pivot 3018. In the illustrated embodiment, the end effector 3016 is configured to act as an endocutter for clamping, severing and stapling tissue, although, in other embodiments, different types of end effectors may be used, such as end effectors for other types of surgical devices, such as graspers, cutters, staplers, clip appliers, access devices, drug/gene therapy devices, ultrasound, RF or laser devices, etc.

[0181] The handle 3012 of the instrument 3010 may include a closure trigger 3022 and a firing trigger 3024 for actuating the end effector 3016. It will be appreciated that instruments having end effectors directed to different surgical tasks may have different numbers or types of triggers or other suitable controls for operating the end effector 3016. The end effector 3016 is shown separated from the handle 3012 by a preferably elongate shaft 3014. In one embodiment, a clinician or operator of the instrument 3010 may articulate the end effector 3016 relative to the shaft 3014 by utilizing the articulation control 3020 as described in more detail in U.S. patent application Ser. No. 11/329,020 entitled SURGICAL INSTRUMENT HAVING AN ARTICULATING END EFFECTOR, now U.S. Pat. No. 7,670,334, which is incorporated herein by reference.

[0182] The end effector 3016 includes in this example, among other things, a staple channel 3026 and a pivotally translatable clamping member, such as an anvil 3028, which are maintained at a spacing that assures effective stapling and severing of tissue clamped in the end effector 3016. The handle 3012 includes a pistol grip 3030 towards which a closure trigger 3022 is pivotally drawn by the clinician to cause clamping or closing of the anvil 3028 toward the staple channel 3026 of the end effector 3016 to thereby clamp tissue positioned between the anvil 3028 and the channel 3026. The firing trigger 3024 is farther outboard of the closure trigger 3022. Once the closure trigger 3022 is locked in the closure position as further described below, the firing trigger 3024 may rotate slightly toward the pistol grip 3030 so that it can be reached by the operator using one hand. The operator may then pivotally draw the firing trigger 3024 toward the pistol grip 3030 to cause the stapling and severing of clamped tissue in the end effector 3016. In other embodiments, different types of clamping members besides the anvil 3028 may be used, such as, for example, an opposing jaw, etc.

[0183] It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician gripping the handle 3012 of an instrument 3010. Thus, the end effector 3016 is distal with respect to the more proximal handle 3012. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical” and “horizontal” are used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.

[0184] The closure trigger 3022 may be actuated first. Once the clinician is satisfied with the positioning of the end effector 3016, the clinician may draw back the closure trigger 3022 to its fully closed, locked position proximate to the pistol grip 3030. The firing trigger 3024 may then be actuated. The firing trigger 3024 returns to the open position (shown in FIGS. 38 and 39) when the clinician removes pressure, as described more fully below. A release button 3032 on the handle 3012, when depressed, may release the locked closure trigger 3022. Various configurations for locking and unlocking the closure trigger 3022 using the release button 3032 are described in U.S. patent application Ser. No. 11/343,573 entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH LOADING FORCE FEEDBACK, now U.S. Pat. No. 7,416,101, which is incorporated herein by reference.

[0185] FIG. 40A is an exploded view of the end effector 3016 according to various embodiments, and FIG. 40B is a perspective view of the cutting instrument of FIG. 40A. As shown in the illustrated embodiment, the end effector 3016 may include, in addition to the previously-mentioned channel 3026 and anvil 3028, a cutting instrument 3034, a staple cartridge 3038 that is removably seated (e.g., installed) in the channel 3026, a sled 3036 disposed within the staple cartridge 3038, and a helical screw shaft 3040.

[0186] The anvil 3028 may be pivotably opened and closed at a pivot point 3042 connected to the proximate end of the channel 3026. The anvil 3028 may also include a tab 3044 at its proximate end that is inserted into a component of the mechanical closure system (described further below) to open and close the anvil 3028. When the closure trigger 3022 is actuated, that is, drawn in by an operator of the instrument 3010, the anvil 3028 may pivot about the pivot point 3042 into the clamped or closed position. If clamping of the end effector 3016 is satisfactory, the operator may actuate the firing trigger 3024, which, as explained in more detail below, causes the cutting instrument 3034 to travel longitudinally along the channel 3026.

[0187] As shown, the cutting instrument 3034 includes upper guide pins 3046 that enter an anvil slot 3048 in the anvil 3028 to verify and assist in maintaining the anvil 3028 in a closed state during staple formation and severing. Spacing between the channel 3026 and anvil 3028 is further maintained by the cutting instrument 3034 by having middle pins 3050 slide along the top surface of the channel 3026 while a bottom foot 3052 opposingly slides along the undersurface of the channel 3026, guided by a longitudinal opening 3054 in the channel 3026. A distally presented cutting surface 3056 between the upper guide pins 3046 and middle pins 3050 severs clamped tissue while distally-presented surface 3058 actuates the staple cartridge 3038 by engaging and progressively driving the sled 3036 through the staple cartridge 3038 from an unfired position located at a proximal end of the staple cartridge 3038 to a fired position located at a distal end of the staple cartridge 3038. When the sled 3036 is in the unfired position, the staple cartridge 3038 is in an unfired, or unspent, state. When the sled 3036 is in the fired position, the staple cartridge 3038 is in a fired, or spent, state. Actuation of the staple cartridge 3038 causes staple drivers 3060 to cam upwardly, driving staples 3062 out of upwardly open staple holes 3064 formed in the staple cartridge 3038. The staples 3062 are subsequently formed against a staple forming undersurface 66 of the anvil 3028. A staple cartridge tray 3068 encompasses from the bottom the other components of the staple cartridge 3038 to hold them in place. The staple cartridge tray 3068 includes a rearwardly open slot 3070 that overlies the longitudinal opening 3054 in the channel 3026. A lower surface of the staple cartridge 3038 and an upward surface of the channel 3026 form a firing drive slot 3200 (FIG. 43) through which the middle pins 3050 pass during distal and proximal movement of the cutting instrument 3034. The sled 3036 may be an integral component of the staple cartridge 3038 such that when the cutting instrument 3034 retracts following the cutting operation, the sled 3036 does not retract. U.S. Pat. No. 6,978,921, entitled SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRING MECHANISM, which is incorporated herein by reference, provides more details about such two-stroke cutting and fastening instruments.

[0188] It should be noted that although the embodiments of the instrument 3010 described herein employ an end effector 3016 that staples the severed tissue, in other embodiments different techniques for fastening or sealing the severed tissue may be used. For example, end effectors that use RF energy or adhesives to fasten the severed tissue may also be used. U.S. Pat. No. 5,709,680 entitled ELECTROSURGICAL HEMOSTATIC DEVICE, and U.S. Pat. No. 5,688,270 entitled ELECTROSURGICAL HEMOSTATIC DEVICE WITH RECESSED AND/OR OFFSET ELECTRODES, both of which are incorporated herein by reference, disclose cutting instruments that uses RF energy to fasten the severed tissue. U.S. patent application Ser. No. 11/267,811 entitled SURGICAL STAPLING INSTRUMENTS STRUCTURED FOR DELIVERY OF MEDICAL AGENTS, now U.S. Pat. No. 7,673,783, and U.S. patent application Ser. No. 11/267,383 entitled SURGICAL STAPLING INSTRUMENTS STRUCTURED FOR PUMP-ASSISTED DELIVERY OF MEDICAL AGENTS, now U.S. Pat. No. 7,607,557, both of which are also incorporated herein by reference, disclose cutting instruments that uses adhesives to fasten the severed tissue. Accordingly, although the description herein refers to cutting/stapling operations and the like, it should be recognized that this is an exemplary embodiment and is not meant to be limiting. Other tissue-fastening techniques may also be used.

[0189] FIGS. 41 and 42 are exploded views and FIG. 43 is a side view of the end effector 3016 and shaft 3014 according to various embodiments. As shown in the illustrated embodiment, the shaft 3014 may include a proximate closure tube 3072 and a distal closure tube 3074 pivotably linked by a pivot links 3076. The distal closure tube 3074 includes an opening 3078 into which the tab 3044 on the anvil 3028 is inserted in order to open and close the anvil 3028, as further described below. Disposed inside the closure tubes 3072, 3074 may be a proximate spine tube 3079. Disposed inside the proximate spine tube 3079 may be a main rotational (or proximate) drive shaft 3080 that communicates with a secondary (or distal) drive shaft 3082 via a bevel gear assembly 3084. The secondary drive shaft 3082 is connected to a drive gear 3086 that engages a proximate drive gear 3088 of the helical screw shaft 3040. The vertical bevel gear 3084b may sit and pivot in an opening 3090 in the distal end of the proximate spine tube 3079. A distal spine tube 3092 may be used to enclose the secondary drive shaft 3082 and the drive gears 3086, 3088. Collectively, the main drive shaft 3080, the secondary drive shaft 3082, and the articulation assembly (e.g., the bevel gear assembly 3084a-c) are sometimes referred to herein as the “main drive shaft assembly.”

[0190] A bearing 3094, positioned at a distal end of the staple channel 3026, receives the helical drive screw 3040, allowing the helical drive screw 3040 to freely rotate with respect to the channel 3026. The helical screw shaft 3040 may interface a threaded opening (not shown) of the cutting instrument 3034 such that rotation of the shaft 3040 causes the cutting instrument 3034 to translate distally or proximately (depending on the direction of the rotation) through the staple channel 3026. Accordingly, when the main drive shaft 3080 is caused to rotate by actuation of the firing trigger 3024 (as explained in further detail below), the bevel gear assembly 3084a-c causes the secondary drive shaft 3082 to rotate, which in turn, because of the engagement of the drive gears 3086, 3088, causes the helical screw shaft 3040 to rotate, which causes the cutting instrument 3034 to travel longitudinally along the channel 3026 to cut any tissue clamped within the end effector 3016. The sled 3036 may be made of, for example, plastic, and may have a sloped distal surface. As the sled 3036 traverses the channel 3026, the sloped distal surface may cam the staple drivers 3060 upward, which in turn push up or drive the staples 3062 in the staple cartridge 3038 through the clamped tissue and against the staple forming undersurface 3066 of the anvil 3028, thereby stapling the severed tissue. When the cutting instrument 3034 is retracted, the cutting instrument 3034 and the sled 3036 may become disengaged, thereby leaving the sled 3036 at the distal end of the channel 3026.

[0191] FIGS. 44-47 illustrate an exemplary embodiment of a motor-driven endocutter, and in particular the handle 3012 thereof, that provides operator-feedback regarding the deployment and loading force of the cutting instrument 3034 in the end effector 3016. In addition, the embodiment may use power provided by the operator in retracting the firing trigger 3024 to power the device (a so-called “power assist” mode). As shown in the illustrated embodiment, the handle 3012 includes exterior lower side pieces 3096, 3098 and exterior upper side pieces 3100, 3102 that fit together to form, in general, the exterior of the handle 3012. A battery 3104 may be provided in the pistol grip portion 3030 of the handle 3012. The battery 3104 may be constructed according to any suitable construction or chemistry including, for example, a Li-ion chemistry such as LiCoO₂ or LiNiO₂, a Nickel Metal Hydride chemistry, etc. The battery 3104 powers a motor 3106 disposed in an upper portion of the pistol grip portion 3030 of the handle 3012. According to various embodiments, the motor 3106 may be a DC brushed driving motor having a maximum rotation of approximately 5000 to 100,000 RPM. The motor 3106 may drive a 90-degree bevel gear assembly 3108 comprising a first bevel gear 3110 and a second bevel gear 3112. The bevel gear assembly 3108 may drive a planetary gear assembly 3114. The planetary gear assembly 3114 may include a pinion gear 3116 connected to a drive shaft 3118. The pinion gear 3116 may drive a mating ring gear 3120 that drives a helical gear drum 3122 via a drive shaft 3124. A ring 3126 may be threaded on the helical gear drum 3122. Thus, when the motor 3106 rotates, the ring 3126 is caused to travel along the helical gear drum 3122 by means of the interposed bevel gear assembly 3108, planetary gear assembly 3114 and ring gear 3120.

[0192] The handle 3012 may also include a run motor sensor 3128 in communication with the firing trigger 3024 to detect when the firing trigger 3024 has been drawn in (or “closed”) toward the pistol grip portion 3030 of the handle 3012 by the operator to thereby actuate the cutting/stapling operation by the end effector 3016. The sensor 3128 may be a proportional sensor such as, for example, a rheostat or variable resistor. When the firing trigger 3024 is drawn in, the sensor 3128 detects the movement, and sends an electrical signal indicative of the voltage (or power) to be supplied to the motor 3106. When the sensor 3128 is a variable resistor or the like, the rotation of the motor 3106 may be generally proportional to the amount of movement of the firing trigger 3024. That is, if the operator only draws or closes the firing trigger 3024 in a little bit, the rotation of the motor 3106 is relatively low. When the firing trigger 3024 is fully drawn in (or in the fully closed position), the rotation of the motor 3106 is at its maximum. In other words, the harder the operator pulls on the firing trigger 3024, the more voltage is applied to the motor 3106, causing a greater rate of rotation. In another embodiment, for example, the control unit (described further below) may output a PWM control signal to the motor 3106 based on the input from the sensor 3128 in order to control the motor 3106.

[0193] The handle 3012 may include a middle handle piece 3130 adjacent to the upper portion of the firing trigger 3024. The handle 3012 also may comprise a bias spring 3132 connected between posts on the middle handle piece 3130 and the firing trigger 3024. The bias spring 3132 may bias the firing trigger 3024 to its fully open position. In that way, when the operator releases the firing trigger 3024, the bias spring 3132 will pull the firing trigger 3024 to its open position, thereby removing actuation of the sensor 3128, thereby stopping rotation of the motor 3106. Moreover, by virtue of the bias spring 3132, any time an operator closes the firing trigger 3024, the operator will experience resistance to the closing operation, thereby providing the operator with feedback as to the amount of rotation exerted by the motor 3106. Further, the operator could stop retracting the firing trigger 3024 to thereby remove force from the sensor 3128, to thereby stop the motor 3106. As such, the operator may stop the deployment of the end effector 3016, thereby providing a measure of control of the cutting/fastening operation to the operator.

[0194] The distal end of the helical gear drum 3122 includes a distal drive shaft 3134 that drives a ring gear 3136, which mates with a pinion gear 3138. The pinion gear 3138 is connected to the main drive shaft 3080 of the main drive shaft assembly. In that way, rotation of the motor 3106 causes the main drive shaft assembly to rotate, which causes actuation of the end effector 3016, as described above.

[0195] The ring 3126 threaded on the helical gear drum 3122 may include a post 3140 that is disposed within a slot 3142 of a slotted arm 3144. The slotted arm 3144 has an opening 3146 its opposite end 3148 that receives a pivot pin 3150 that is connected between the handle exterior side pieces 3096, 3098. The pivot pin 3150 is also disposed through an opening 3152 in the firing trigger 3024 and an opening 3154 in the middle handle piece 3130.

[0196] In addition, the handle 3012 may include a reverse motor (or end-of-stroke) sensor 3156 and a stop motor (or beginning-of-stroke) sensor 3158. In various embodiments, the reverse motor sensor 3156 may be a normally-open limit switch located at the distal end of the helical gear drum 3122 such that the ring 3126 threaded on the helical gear drum 3122 contacts and closes the reverse motor sensor 3156 when the ring 3126 reaches the distal end of the helical gear drum 3122. The reverse motor sensor 3156, when closed, sends a signal to the control unit which sends a signal to the motor 3106 to reverse its rotation direction, thereby withdrawing the cutting instrument of the end effector 3016 following the cutting operation.

[0197] The stop motor sensor 3158 may be, for example, a normally-closed limit switch. In various embodiments, it may be located at the proximate end of the helical gear drum 3122 so that the ring 3126 opens the switch 3158 when the ring 3126 reaches the proximate end of the helical gear drum 3122.

[0198] In operation, when an operator of the instrument 3010 pulls back the firing trigger 3024, the sensor 3128 detects the deployment of the firing trigger 3024 and sends a signal to the control unit which sends a signal to the motor 3106 to cause forward rotation of the motor 3106 at, for example, a rate proportional to how hard the operator pulls back the firing trigger 3024. The forward rotation of the motor 3106 in turn causes the ring gear 3120 at the distal end of the planetary gear assembly 3114 to rotate, thereby causing the helical gear drum 3122 to rotate, causing the ring 3126 threaded on the helical gear drum 3122 to travel distally along the helical gear drum 3122. The rotation of the helical gear drum 3122 also drives the main drive shaft assembly as described above, which in turn causes deployment of the cutting instrument 3034 in the end effector 3016. That is, the cutting instrument 3034 and sled 3036 are caused to traverse the channel 3026 longitudinally, thereby cutting tissue clamped in the end effector 3016. Also, the stapling operation of the end effector 3016 is caused to happen in embodiments where a stapling-type end effector is used.

[0199] By the time the cutting/stapling operation of the end effector 3016 is complete, the ring 3126 on the helical gear drum 3122 will have reached the distal end of the helical gear drum 3122, thereby causing the reverse motor sensor 3156 to be actuated, which sends a signal to the control unit which sends a signal to the motor 3106 to cause the motor 3106 to reverse its rotation. This in turn causes the cutting instrument 3034 to retract, and also causes the ring 3126 on the helical gear drum 3122 to move back to the proximate end of the helical gear drum 3122.

[0200] The middle handle piece 3130 includes a backside shoulder 3160 that engages the slotted arm 3144 as best shown in FIGS. 45 and 46. The middle handle piece 3130 also has a forward motion stop 3162 that engages the firing trigger 3024. The movement of the slotted arm 3144 is controlled, as explained above, by rotation of the motor 3106. When the slotted arm 3144 rotates CCW as the ring 3126 travels from the proximate end of the helical gear drum 3122 to the distal end, the middle handle piece 3130 will be free to rotate CCW. Thus, as the operator draws in the firing trigger 3024, the firing trigger 3024 will engage the forward motion stop 3162 of the middle handle piece 3130, causing the middle handle piece 3130 to rotate CCW. Due to the backside shoulder 3160 engaging the slotted arm 3144, however, the middle handle piece 3130 will only be able to rotate CCW as far as the slotted arm 3144 permits. In that way, if the motor 3106 should stop rotating for some reason, the slotted arm 3144 will stop rotating, and the operator will not be able to further draw in the firing trigger 3024 because the middle handle piece 3130 will not be free to rotate CCW due to the slotted arm 3144.

[0201] FIGS. 48 and 49 illustrate two states of a variable sensor that may be used as the run motor sensor 3128 according to various embodiments of the present invention. The sensor 3128 may include a face portion 3164, a first electrode (A) 3166, a second electrode (B) 3168, and a compressible dielectric material 3170 (e.g., EAP) between the electrodes 3166, 3168. The sensor 3128 may be positioned such that the face portion 3164 contacts the firing trigger 3024 when retracted. Accordingly, when the firing trigger 3024 is retracted, the dielectric material 3170 is compressed, as shown in FIG. 49, such that the electrodes 3166, 3168 are closer together. Since the distance “b” between the electrodes 3166, 3168 is directly related to the impedance between the electrodes 3166, 3168, the greater the distance the more impedance, and the closer the distance the less impedance. In that way, the amount that the dielectric material 3170 is compressed due to retraction of the firing trigger 3024 (denoted as force “F” in FIG. 49) is proportional to the impedance between the electrodes 3166, 3168. This impedance provided by the sensor 3128 may be used with suitable signal conditioning circuitry to proportionally control the speed of the motor 3106, for example.

[0202] Components of an exemplary closure system for closing (or clamping) the anvil 3028 of the end effector 3016 by retracting the closure trigger 3022 are also shown in FIGS. 44-47. In the illustrated embodiment, the closure system includes a yoke 3172 connected to the closure trigger 3022 by a pin 3174 that is inserted through aligned openings in both the closure trigger 3022 and the yoke 3172. A pivot pin 3176, about which the closure trigger 3022 pivots, is inserted through another opening in the closure trigger 3022 which is offset from where the pin 3174 is inserted through the closure trigger 3022. Thus, retraction of the closure trigger 3022 causes the upper part of the closure trigger 3022, to which the yoke 3172 is attached via the pin 3174, to rotate CCW. The distal end of the yoke 3172 is connected, via a pin 3178, to a first closure bracket 3180. The first closure bracket 3180 connects to a second closure bracket 3182. Collectively, the closure brackets 3180, 3182 define an opening in which the proximal end of the proximate closure tube 3072 (see FIG. 41) is seated and held such that longitudinal movement of the closure brackets 3180, 3182 causes longitudinal motion by the proximate closure tube 3072. The instrument 3010 also includes a closure rod 3184 disposed inside the proximate closure tube 3072. The closure rod 3184 may include a window 3186 into which a post 3188 on one of the handle exterior pieces, such as exterior lower side piece 3096 in the illustrated embodiment, is disposed to fixedly connect the closure rod 3184 to the handle 3012. In that way, the proximate closure tube 3072 is capable of moving longitudinally relative to the closure rod 3184. The closure rod 3184 may also include a distal collar 3190 that fits into a cavity 3192 in proximate spine tube 3079 and is retained therein by a cap 3194 (see FIG. 41).

[0203] In operation, when the yoke 3172 rotates due to retraction of the closure trigger 3022, the closure brackets 3180, 3182 cause the proximate closure tube 3072 to move distally (i.e., away from the handle 3012 of the instrument 3010), which causes the distal closure tube 3074 to move distally, which causes the anvil 3028 to rotate about the pivot point 3042 into the clamped or closed position. When the closure trigger 3022 is unlocked from the locked position, the proximate closure tube 3072 is caused to slide proximally, which causes the distal closure tube 3074 to slide proximally, which, by virtue of the tab 3044 being inserted in the opening 3078 of the distal closure tube 3074, causes the anvil 3028 to pivot about the pivot point 3042 into the open or unclamped position. In that way, by retracting and locking the closure trigger 3022, an operator may clamp tissue between the anvil 3028 and channel 3026, and may unclamp the tissue following the cutting/stapling operation by unlocking the closure trigger 3022 from the locked position.

[0204] The control unit (described further below) may receive the outputs from end-of-stroke and beginning-of-stroke sensors 3156, 3158 and the run-motor sensor 3128, and may control the motor 3106 based on the inputs. For example, when an operator initially pulls the firing trigger 3024 after locking the closure trigger 3022, the run-motor sensor 3128 is actuated. If the control unit determines that an unspent staple cartridge 3038 is present in the end effector 3016, as described further below, the control unit may output a control signal to the motor 3106 to cause the motor 3106 to rotate in the forward direction. When the end effector 3016 reaches the end of its stroke, the reverse motor sensor 3156 will be activated. The control unit may receive this output from the reverse motor sensor 3156 and cause the motor 3106 to reverse its rotational direction. When the cutting instrument 3034 is fully retracted, the stop motor sensor switch 3158 is activated, causing the control unit to stop the motor 3106.

[0205] According to various embodiments, the instrument 3010 may include a transponder in the end effector 3016. The transponder may generally be any device suitable for transmitting a wireless signal(s) indicating one or more conditions of the end effector 3016. In certain embodiments, for example, wireless signals may be transmitted by the transponder to the control unit responsive to wireless signals received from the control unit. In such embodiments, the wireless signals transmitted by the control unit and the transponder are referred to as “interrogation” and “reply” signals, respectively. The transponder may be in communication with one or more types of sensors (e.g., position sensors, displacement sensors, pressure/load sensors, proximity sensors, etc.) located in the end effector 3016 for transducing various end effector conditions such as, for example, a state of the staple cartridge 3038 (e.g., fired or unfired) and the respective positions of the anvil 3028 (e.g., open or closed) and the sled 3036 (e.g., proximal or distal). According to various embodiments and as discussed below, the transponder may be a passive device such that its operating power is derived from wireless signals (e.g., interrogation signals). In other embodiments, the transponder may be an active device powered by a self-contained power source (e.g., a battery) disposed within the end effector 3016. The transponder and the control circuit may be configured to communicate using any suitable type of wireless signal. According to various embodiments and as discussed below, for example, the transponder and the control circuit may transmit and receive wireless signals using magnetic fields generated by inductive effects. It will be appreciated that the transponder and the control circuit may instead transmit and receive wireless signals using electromagnetic fields (e.g., RF signals, optical signals), or using electric fields generated by capacitive effects, for example. It will further be appreciated that the end effector 3016 may include additional transponders, with each transponder having one more dedicated sensors for inputting data thereto.

[0206] FIG. 50 illustrates a block diagram of the control unit 3196 according to various embodiments. As shown, the control unit 3196 may comprise a processor 3198 and one or more memory units 3200. The control unit 3196 may be powered by the battery 3104 or other suitable power source contained within the instrument 3010. In certain embodiments, the control unit 3196 may further comprise an inductive element 3202 (e.g., a coil or antenna) to transmit and receive wireless signals (e.g., interrogation and reply signals) from the transponder via magnetic fields. Signals received by the inductive element 3202 may be demodulated by a demodulator 3204 and decoded by a decoder 3206. By executing instruction code stored in the memory 3200, the processor 3198 may control various components of the instrument 3010, such as the motor 3106 and a user display (not shown), based on inputs of the end effector sensors (as indicated by the decoded signals) and inputs received from other various sensor(s) (such as the run-motor sensor 3128, the end-of-stroke and beginning-of-stroke sensors 3156, 3158, for example).

[0207] Wireless signals output by the control unit 3196 may be in the form of alternating magnetic fields emitted by the inductive element 3202. The control unit 3196 may comprise an encoder 3208 for encoding data to be transmitted to the transponder and a modulator 3210 for modulating the magnetic field based on the encoded data using a suitable modulation scheme. The control unit 3196 may communicate with the transponder using any suitable wireless communication protocol and any suitable frequency (e.g., an ISM band or other RF band). Also, the control unit 3196 may transmit signals at a different frequency range than the frequency range of the reply signals received from the transponder. Additionally, although only one antenna (inductive element 3202) is shown in FIG. 50, in other embodiments the control unit 3196 may have separate receiving and transmitting antennas.

[0208] According to various embodiments, the control unit 3196 may comprise a microcontroller, a microprocessor, a field programmable gate array (FPGA), one or more other types of integrated circuits (e.g., RF receivers and PWM controllers), and/or discrete passive components. The control unit 3196 may also be embodied as system-on-chip (SoC) or a system-in-package (SIP), for example.

[0209] As shown in FIG. 51, the control unit 3196 may be housed in the handle 3012 of the instrument 3010 and the transponder 3212 may be located in the end effector 3016. To transmit signals to the transponder 3212 and receive signals therefrom, the inductive element 3202 of the control unit 3196 may be inductively coupled to a secondary inductive element (e.g., a coil) 3214 positioned in the shaft 3014 distally from the rotation joint 3019. The secondary inductive element 3214 is preferably electrically insulated from the conductive shaft 3014.

[0210] The secondary inductive element 3214 may be connected by an electrically conductive, insulated wire 3216 to a distal inductive element (e.g., a coil) 3218 located near the end effector 3016, and preferably distally located relative to the articulation pivot 3018. The wire 3216 may be made of an electrically conductive polymer and/or metal (e.g., copper) and may be sufficiently flexible so that it could pass though the articulation pivot 3018 and not be damaged by articulation. The distal inductive element 3218 may be inductively coupled to the transponder 3212 in, for example, the staple cartridge 3038 of the end effector 3016. The transponder 3212, as described in more detail below, may include an antenna (or coil) for inductively coupling to the distal coil 3218, as well as associated circuitry for transmitting and receiving wireless signals.

[0211] In certain embodiments, the transponder 3212 may be passively powered by magnetic fields emitted by the distal inductive element 3218. Once sufficiently powered, the transponder 3212 may transmit and/or receive data (e.g., by modulating the magnetic fields) to the control unit 3196 in the handle 3012 via (i) the inductive coupling between the transponder 3212 and the distal inductive element 3218, (ii) the wire 3216, and (iii) the inductive coupling between the secondary inductive element 3214 and the control unit 3196. The control unit 3196 may thus communicate with the transponder 3212 in the end effector 3016 without a hardwired connection through complex mechanical joints like the rotating joint 3019 and/or without a hardwired connection from the shaft 3014 to the end effector 3016, places where it may be difficult to maintain such connections. In addition, because the distances between the inductive elements (e.g., the spacing between (i) the transponder 3212 and the distal inductive element 3218, and (ii) the secondary inductive element 3214 and the control unit 3196) are fixed and known, the couplings could be optimized for inductive energy transfer. Also, the distances could be relatively short so that relatively low power signals could be used to thereby minimize interference with other systems in the use environment of the instrument 3010.

[0212] In the embodiment of FIG. 51, the inductive element 3202 of the control unit 3196 is located relatively near to the control unit 3196. According to other embodiments, as shown in FIG. 52, the inductive element 3202 of the control unit 3196 may be positioned closer to the rotating joint 3019 to that it is closer to the secondary inductive element 3214, thereby reducing the distance of the inductive coupling in such an embodiment. Alternatively, the control unit 3196 (and hence the inductive element 3202) could be positioned closer to the secondary inductive element 3214 to reduce the spacing.

[0213] In other embodiments, more or fewer than two inductive couplings may be used. For example, in some embodiments, the surgical instrument 3010 may use a single inductive coupling between the control unit 3196 in the handle 3012 and the transponder 3212 in the end effector 3016, thereby eliminating the inductive elements 3214, 3218 and the wire 3216. Of course, in such an embodiment, stronger signals may be required due to the greater distance between the control unit 3196 in the handle 3012 and the transponder 3212 in the end effector 3016. Also, more than two inductive couplings could be used. For example, if the surgical instrument 3010 had numerous complex mechanical joints where it would be difficult to maintain a hardwired connection, inductive couplings could be used to span each such joint. For example, inductive couplings could be used on both sides of the rotary joint 3019 and both sides of the articulation pivot 3018, with an inductive element 3220 on the distal side of the rotary joint 3019 connected by the wire 3216 to the inductive element 3218 of the proximate side of the articulation pivot, and a wire 3222 connecting inductive elements 3224, 3226 on the distal side of the articulation pivot 3018 as shown in FIG. 53. In this embodiment, the inductive element 3226 may communicate with the transponder 3212.

[0214] In the above-described embodiments, each of the inductive elements 3202, 3214, 3218, 3224, 3226 may or may not include ferrite cores. Additionally, the inductive elements 3214, 3218, 3224, 3226 are also preferably insulated from the electrically conductive outer shaft (or frame) of the instrument 3010 (e.g., the closure tubes 3072, 3074), and the wires 3216, 3222 are also preferably insulated from the outer shaft 3014.

[0215] FIG. 54 is a bottom view of a portion of the staple cartridge 3038 including the transponder 3212 according to various embodiments. As shown, the transponder 3212 may be held or embedded in the staple cartridge 3038 at its distal end using a suitable bonding material, such as epoxy.

[0216] FIG. 55 illustrates a circuit diagram of the transponder 3212 according to various embodiments. As shown, the transponder 3212 may include a resonant circuit 3249 comprising an inductive element 3250 (e.g., a coil or antenna) and a capacitor 3252. The transponder 3212 may further include a microchip 3254 coupled to the resonant circuit 3249. In certain embodiments, the microchip 3254 may be, for example, an RFID device containing circuitry for enabling communication with the control unit 3196 via the inductive element 3250 of the resonant circuit 3249. The microchip 3254 may include at least one data input for receiving data in the form of discrete or analog signals from the sensors 3235 disposed in the end effector 3016. As discussed above, the sensors 3235 may include, for example, position sensors, displacement sensors, pressure/load sensors, proximity sensors for sensing various end effector conditions. The microchip 3254 also may include one or more dynamic memory devices 3255 (e.g., flash memory devices) for storing data transmitted from, for example, the control unit 3196. The microchip 3254 may further include one or more non-dynamic memory devices 3257 (e.g., write-once memory devices) for storing static data, such as, for example, a staple cartridge identification number, manufacturer information, and information pertaining to physical characteristics of the staple cartridge 3038.

[0217] In response to alternating magnetic fields emitted by the distal inductive element 3218, the resonant circuit 3249 of the transponder 3212 is caused to resonate, thereby causing an alternating input voltage to be applied to the microchip 3254. The resonant circuit 3249 may have a resonant frequency given by

$f_r=\frac{1}{2\pi \sqrt{L_1C_1}},$

where L₁ is the inductance value of the inductive element 3250 and C₁ is the capacitance value of the capacitor 3252. The values of L₁ and C₁ may be selected such that the resonant frequency of the circuit 3249 is equal or nearly equal to the frequency of magnetic field transmitted by the distal inductive element 3218. The circuitry of the microchip 3254 may include a rectifying circuitry (not shown) for rectifying and conditioning the alternating input voltage to provide a DC voltage sufficient to power the microchip 3254. Once powered, the microchip 3254 may selectively load the inductive element 3250 based on data received from the sensors 3235 and the data stored in the memory devices 3255, 3257, thus modulating the magnetic fields coupling the distal inductive element 3218 and the inductive element 3250. The modulation of the magnetic field modulates the voltage across the distal inductive element 3218, which in turn modulates the voltage across the inductive element 3202 of the control unit 3196. The control unit 3196 may demodulate and decode the voltage signal across the inductive element 3202 to extract data communicated by the microchip 3254. The control unit 3196 may process the data to verify, among other things, that the staple cartridge 3038 is compatible with the instrument 3010 and that end effector conditions are suitable for conducting a firing operation. Subsequent to verification of the data, the control unit 3196 may enable a firing operation.

[0218] According to various embodiments, the resonant circuit 3249 may further include a fuse 3256 connected in series with the inductive element 3250. When the fuse 3256 is closed (e.g., conductive), the inductive element 3250 is electrically coupled to the resonant circuit 3249, thus enabling the transponder 3212 to function as described above in response to an alternating magnetic field emitted by the distal inductive element 3218. The closed state of the fuse 3256 thus corresponds to an enabled state of the transponder 3212. When the fuse 3256 is opened (e.g., non-conductive), the inductive element 3250 is electrically disconnected from the resonant circuit 3249, thus preventing the resonant circuit 3249 from generating the voltage necessary to operate the microchip 3254. The open state of the fuse 3256 thus corresponds to a disabled state of the transponder 3212. The placement of the fuse 3256 in FIG. 55 is shown by way of example only, and it will be appreciated that the fuse 3256 may be connected in any manner such that the transponder 3212 is disabled when the fuse 3256 is opened.

[0219] According to various embodiments, the fuse 3256 may be actuated (e.g., transitioned from closed to opened) substantially simultaneously with a firing operation of the instrument 3010. For example, the fuse 3256 may be actuated immediately before, during, or immediately after a firing operation. Actuation of the fuse 3256 thus transitions the transponder 3212 from the enabled state to the disabled state. Accordingly, if an attempt is made to reuse the staple cartridge 3038, the transponder 3212 will be unable to communicate data in response to a wireless signal transmitted by the distal inductive element 3218. Based upon the absence of this data, the control unit 3196 may determine that the transponder 3212 is in a disabled state indicative of the fired state of the staple cartridge 3038 and prevent a firing operation from being enabled. Thus, actuation of the fuse 3256 prevents reuse of a staple cartridge 3038 when the staple cartridge 3038 is in the fired state.

[0220] In certain embodiments, the fuse 3256 may be a mechanically-actuated fuse that is opened in response to movement of the cutting instrument 3034 when actuated, for example. As shown in FIG. 56, for example, the fuse 3256 may include a section of wire extending transversely across a longitudinal slot 3258 of the staple cartridge 3038 through which the cutting instrument 3034 passes during a firing operation. When the instrument 3010 is fired, the distal movement of the cutting instrument 3034 severs the fuse 3256, thus transitioning the transponder 3212 to the disabled state so that it cannot be reused.

[0221] According to other embodiments, the fuse 3256 may be an electrically-actuated fuse. For example, subsequent to receiving data from the transponder 3212 and verifying that the end effector 3016 is in a condition to be fired, the control unit 3196 may transmit a wireless signal to the transponder 3212 such that the resulting current flow through fuse 3256 is sufficient to cause the fuse 3256 to open. It will be appreciated that the strength of the wireless signal needed to open the fuse 3256 may be different in amplitude, frequency, and duration than that used to communicate with the transponder 3212. Additionally, it will be appreciated that other electrically-actuated components may be used instead of an electrically-actuated fuse to disable the transponder 3212. For example, the control unit 3196 may transmit a wireless signal to the transponder 3212 such that resulting voltage developed across the resonant circuit 3256 sufficiently exceeds the voltage rating of the capacitor 3252 and/or circuitry of the microchip 3254 to cause their destruction.

[0222] As an alternative to using an electrically-actuated fuse, the fuse 3256 may instead be a thermally-actuated fuse (e.g., a thermal cutoff fuse) that is caused to open in response to heat generated by the flow of excessive current therethrough.

[0223] In certain cases, it may be desirable to communicate with the transponder 3212 when the staple cartridge 3038 is in the fired state. In such cases, it is not possible to entirely disable the transponder 3212 as described in the embodiments above. FIG. 57 illustrates a circuit diagram of the transponder 3212 according to various embodiments for enabling wireless communication with the control unit 3196 when the staple cartridge 3038 is in the fired state. As shown, the resonant circuit 3249 of the transponder 3212 may include a second capacitor 3260 in parallel with the capacitor 3252. The fuse 3256 may be connected in series with the second capacitor 3260 such that the resonant frequency of the resonant circuit 3249 is determined by the open/closed state of the fuse 3256. In particular, when the fuse 3256 is closed, the resonant frequency is given by

$f_r=\frac{1}{2\pi \sqrt{L_1\left(C_1+C_2\right)}},$

where C₂ is the capacitance value of the second capacitor 3260. The closed state of the fuse 3256 thus corresponds to a first resonant state of the transponder 3212. When the fuse 3256 is opened, the resonant frequency is given by

$f_r=\frac{1}{2\pi \sqrt{L_1C_1}}.$

The open state of the fuse 3256 thus corresponds to a second resonant state of the transponder 3212. As described in the above embodiments, the fuse 3256 may be mechanically, electrically or thermally actuated substantially simultaneously with a firing operation. The control unit 3196 may be configured to determine the resonant state of the transponder 3212 (and thus the unfired/fired state of the staple cartridge 3038) by discriminating between the two resonant frequencies. Advantageously, because the resonant circuit 3256 (and thus the microchip 3254) continue to operate after the fuse 3256 is opened, the control unit 3196 may continue to receive data from the transponder 3212. It will be appreciated that the placement of the fuse 3256 and use of the second capacitor 3260 to alter the resonant frequency is provided by way of example only. In other embodiments, for example, the fuse 3256 may be connected such that the inductive value of the inductive element 3250 is changed when the fuse 3256 is opened (e.g., by connecting the fuse 3256 such that a portion of the inductive element 3250 is short-circuited when the fuse 3256 is closed).

[0224] According to various embodiments, a switch may be used as an alternative to the fuse 3256 for effecting the transition between transponder states. For example, as shown in FIG. 58, the staple cartridge tray 3068 of the staple cartridge 3038 may include a switch 3262 (e.g., a normally-open limit switch) located at its proximal end. The switch 3262 may be mounted such that when the sled 3036 is present in the unfired position, the sled 3036 maintains the switch 3262 in a closed (e.g., conductive) state. When the sled 3036 is driven from the unfired position to the fired position during a firing operation, the switch 3262 transitions to an open (e.g., non-conductive state), thus effecting a transition in the state of the transponder 3212 as described above. It will be appreciated that in other embodiments the switch 3262 may be a normally-closed switch mounted at the distal end of the staple cartridge tray 3068 such that the switch 3262 is caused to open when the sled 3036 is present in the fired position. It will further be appreciated that the switch 3262 may be located at the proximal or distal ends of the staple cartridge 3038 and mounted such that it may be suitably actuated by the sled 3036 when present in the unfired and fired positions, respectively.

[0225] As an alternative to connecting the mechanically-actuated fuse 3256 or the switch 3262 to disable/alter the resonant circuit 3249, these components may instead be connected to data inputs of the microchip 3254. In this way, the open/closed states of the mechanically-actuated fuse 3256 or the switch 3262 may be transmitted to the control unit 3196 in the same manner as the data corresponding to other end effector conditions.

[0226] As an alternative to the fuse 3256 and the switch 3262, embodiments of the present invention may instead utilize alterable data values in a dynamic memory device 3255 of the transponder 3212. For example, the dynamic memory device 3255 may store a first data value (e.g., a data bit having a value of 1) corresponding to a first data state of the transponder 3212. The first data value may be written to the dynamic memory device 3255 during the manufacture of the staple cartridge 3038, for example. The first data state may thus be indicative of the unfired state of the staple cartridge 3038. Based on a determination of the first data state of the transponder 3212, the control unit 3196 may enable operation of the instrument 3010 if the end effector conditions are otherwise suitable for conducting a firing operation. Substantially simultaneously with the firing operation, the control unit 3196 may transmit a wireless signal to the transponder 3212 containing a second data value (e.g., a data bit having a value of 0). The second data value may be stored to the dynamic memory device 3255 such that the first data value is overwritten, thus transitioning the transponder 3212 from the first data state to a second data state. The second data state may thus be indicative of the fired state of the staple cartridge 3038. If an attempt is made to reuse the staple cartridge 3038, the control unit 3196 may determine that the transponder 3212 is in the second data state and prevent a firing operation from being enabled.

[0227] Although the transponders 3212 in the above-described embodiments includes a microchip 3254 for wirelessly communicating data stored in memory devices 3235, 3237 and data input from the sensors 3235, in other embodiments the transponder may not include a microchip 3254. For example, FIG. 59 illustrates a “chipless” transponder 3264 in the form of a resonant circuit having components similar to those of the resonant circuit 3249, such as an inductive element 3250, a capacitor 3252, and a fuse 3256. Additionally, the transponder 3264 may include one or more sensors 3235 connected in series with the components 3250, 3252, 3256. In certain embodiments and as shown, each sensor 3235 may be a limit switch (e.g., a normally open or a normally closed limit switch) mounted in the end effector 3016 for sensing a corresponding end effector condition (e.g., a position of the anvil 3028, a position of the sled 3036, etc.). In such embodiments, each limit switch 3235 may be in a closed (e.g., conductive) state when its sensed condition is compatible with a firing operation, thus establishing electrical continuity through the resonant circuit.

[0228] When each switch 3235 and the fuse 3256 is in the closed state, the resonant circuit will be caused to resonate at a frequency f_r responsive to a magnetic field emitted by the distal inductive element 3218. The closed states of the fuse 3256 and the switches 3235 thus correspond to an enabled state of the transponder 3264 that is indicative of, among other things, the unfired state of the staple cartridge 3038. The control unit 3196 may sense the resonance (e.g., by sensing magnetic field loading caused by the resonant circuit) to determine the enabled state, at which time the control unit 3196 may enable operation of the instrument 3010. Substantially simultaneously with the actuation of the cutting instrument 3034, the fuse 3256 may be mechanically, electronically or thermally actuated as described above, thus transitioning the transponder 3264 to a disabled state indicative of the fired state of the staple cartridge 3038. If a subsequent firing operation is attempted without replacing the staple cartridge 3038, the control unit 3196 may determine the disabled state based on the absence of a sensed resonance in response to an emitted magnetic field, in which case the control unit 3196 prevents the firing operation from being performed.

[0229] FIG. 60 illustrates another embodiment of a chipless transponder 3264 in the form of a resonant circuit including an inductive element 3250, a first capacitor 3252, a second capacitor 3260, and a fuse 3256 connected in series with the second capacitor 3260. The fuse 3256 may be mechanically, electronically or thermally actuated substantially simultaneously with a firing operation, as in above-described embodiments. The transponder 3264 may additionally include one or more sensors 3235 (e.g., limit switches) connected in series with a third capacitor 3266 of the resonant circuit. Accordingly, when each switch 3235 and the fuse 3256 are in the closed state, the resonant circuit will be caused to resonate at a frequency

$f_{r1}=\frac{1}{2\pi \sqrt{L_1\left(C_1+C_2+C_3\right)}}$

responsive to a magnetic field emitted by the distal inductive element 3218. When one of the switches 3235 is opened and the fuse 3256 is closed, the resonant frequency will be

$f_{r2}=\frac{1}{2\pi \sqrt{L_1\left(C_1+C_2\right)}},$

and when each of the switches 3235 is closed and the fuse 3256 is opened, the resonant frequency will be

$f_{r3}=\frac{1}{2\pi \sqrt{L_1\left(C_1+C_3\right)}}.$

When the switches 3235 and the fuse 3256 are opened, the resonant frequency will be

$f_{r4}=\frac{1}{2\pi \sqrt{L_1C_1}}.$

The closed states of the fuse 3256 and the switches 3235 correspond to a first resonant state (e.g., resonant frequency f_r1) of the transponder 3264, and the open state of the fuse 3256 corresponds to a second resonant state (e.g., either of resonant frequencies f_r3 or f_r4). The capacitance values C₁, C₂ and C₃ may be selected such that the resonant frequencies f_r1, f_r2, f_r3 and f_r4 are different. The control unit 3196 may be configured to discriminate between resonant frequencies to determine the first or second state of the transponder 3266 (and thus the unfired or fired state of the staple cartridge 3038), and to enable or prevent operation of the instrument 3010 accordingly. The control unit 3196 may further be configured to determine a third state of the transponder 3264 corresponding the closed state of the fuse 3256 and an open state of any of the switches 3235. In this case, the control unit 3196 may operate to prevent a firing operation until the end effector condition(s) causing the open switch(es) 3235 is resolved.

[0230] FIG. 61 is a flow diagram of a method of preventing reuse of a staple cartridge in surgical instrument that may be performed in conjunction with embodiments of the instrument 3010 described above. At step 3300, a first wireless signal is transmitted to the transponder 3212, 3264 and at step 3305 a second wireless signal is received from the transponder 3212, 3264 such that one of a first electronic state and a second electronic state of the transponder 3212, 3264 may be determined based on the second wireless signal. In certain embodiments and as explained above, the wireless signals may be magnetic signals generated by inductive effects, although electric fields and electromagnetic fields may alternatively be employed. States of the transponder 3212, 3264 are indicative of states of the staple cartridge 3038. In certain embodiments, for example, the first and second transponder states may indicate the unfired and fired states of the staple cartridge 3038, respectively.

[0231] At step 3310, if the first electronic state (indicative of an unfired staple cartridge state) is determined, the cutting instrument 3034 may be enabled at step 3315. After the instrument 3010 is enabled, the operator may initiate a firing operation when ready.

[0232] At step 3320, the transponder 3212, 3264 may be transitioned from the first electronic state to the second electronic state substantially simultaneously with an actuation of the cutting instrument 3034. Accordingly, if an attempt is made to reuse the staple cartridge 3038 at step 3300, the second electronic state of the transponder 3212, 3264 (indicative of the fired staple cartridge state) may be determined at step 3310 and a firing operation consequently prevented, as shown at step 3325.

[0233] Above-described embodiments advantageously prevent operation of the instrument 3010 when a spent staple cartridge 3038 (or no staple cartridge 3038) is present in the end effector 3016, thus preventing cutting of tissue without simultaneous stapling. In addition to preventing operation of the instrument 3010 under such circumstances, it may further be desirable to prevent operation of the instrument 3010 after it has been used to perform a predetermined number of firing operations. Limiting the number of firing operations may be necessary, for example, so that use of the instrument 3010 does not cause operational lifetimes of its various components (e.g., the cutting instrument 3034, the battery 3104, etc.) to be exceeded.

[0234] According to various embodiments, a limit on the number of firing operations may be implemented by the control unit 3196 using, for example, a counter (not shown) contained within the processor 3198. The counter may be incremented once for each firing operation indicated by one or more sensor inputs received by the control unit 3196 (e.g., inputs received from the end-of-stroke and beginning-of-stroke sensors 3156, 3158 and the run-motor sensor 3128). Subsequent to each firing operation, the processor 3198 may compare the counter contents to a predetermined number. The predetermined number may be stored in the memory 3200 of the processor 3198 during instrument manufacture, for example, and represent the maximum number of firing operations performable by the instrument 3010. The predetermined number may be determined based upon, among other things, operational lifetimes of the various instrument components and/or the expected requirements of a medical procedure for which the instrument 3010 is to be used. When the counted number of firing operations is equal to the predetermined number, the control unit 3196 may be configured to prevent additional firing operations by the instrument 3010. In embodiments in which the control unit 3196 directly or indirectly controls rotation of the motor 3106 (e.g., via a PWM signal output in response to an input from the run-motor sensor 3128), instruction code stored in the memory 3200 may cause the processor 3198 to prevent further output of power and/or control signals necessary for motor operation.

[0235] In other embodiments, the control unit 3196 may prevent firing operations in excess of the predetermined number by disabling electronic components necessary for motor operation. For example, as shown in FIG. 62, the control unit 3196 may be connected to the motor 3106 via conductive leads 3268, one of which includes an electronically-actuated fuse 3270. Subsequent to the retraction of the cutting instrument 3034 after the final firing operation (e.g., when the number of firing operations is equal to the predetermined number), the control unit 3196 may cause increased current to be applied to the motor 3106 such that the fuse 3270 is opened (e.g., rendered non-conductive), thus preventing further motor operation. It will be appreciated that the placement of the fuse 3270 is shown by way of example only, and that the fuse 3270 may be connected in other ways to effect the same result. For example, the fuse 3270 may be connected between the battery 3104 and the electrical components of the instrument 3010. In such embodiments, when the number of firing operations equals the predetermined number, the control unit 3196 may short circuit the fuse 3270 such that it is caused to open, thus removing power from the electrical components.

[0236] As an alternative to the fuse 3270, it will be appreciated that a switch (e.g., a relay contact) controllable by a discrete output of the control unit 3196 may be used instead. Additionally, it will be appreciated the control unit 3196 may be configured to electronically disable one or more components necessary for motor operation (e.g., capacitors, transistors, etc.) other than a fuse by applying excessive voltages and/or currents thereto. Such components may be internal or external to the control unit 3196.

[0237] Although above-described embodiments for limiting instrument use utilize a counter within the processor 3198, it will be appreciated that other embodiments may utilize an electro-mechanical counter having a mechanical input suitably coupled to a component of the instrument 3010 (e.g., the firing trigger 3024) such that the counter is incremented once for each firing operation. The counter may include a set of electrical contacts that close (or open) when the counted number of firing operations exceeds a predetermined number stored within the counter. The contacts may serve as an input to the control unit 3196, and the processor 3198 may be programmed to enable or disable instrument operation based on the state of the contacts. Alternatively, the contacts may be connected to other components of the instrument (e.g., the battery 3104 or the motor 3106) such that power to the motor 3106 is interrupted when the predetermined number of counts is exceeded.

[0238] In the embodiments described above, the battery 3104 powers (at least partially) the firing operation of the instrument 3010. As such, the instrument may be a so-called “power-assist” device. More details and additional embodiments of power-assist devices are described are described in U.S. patent application Ser. No. 11/343,573 referenced above, now U.S. Pat. No. 7,416,101, which is incorporated herein. It should be recognized, however, that the instrument 3010 need not be a power-assist device and that this is merely an example of a type of device that may utilize aspects of the present invention. For example, the instrument 3010 may include a user display (such as a LCD or LED display) that is powered by the battery 3104 and controlled by the control unit 3196. Data from the transponder 3212, 3264 in the end effector 3016 may be displayed on such a display.

[0239] In another embodiment, the shaft 3014 of the instrument 3010, including for example, the proximate closure tube 3072 and the distal closure tube 3074, may collectively serve as part of an antenna for the control unit 3196 by radiating signals to the transponder 3212, 3264 and receiving radiated signals from the transponder 3212, 3264. That way, signals to and from the transponder 3212, 3264 in the end effector 3016 may be transmitted via the shaft 3014 of the instrument 3010.

[0240] The proximate closure tube 3072 may be grounded at its proximate end by the exterior lower and upper side pieces 3096, 3098, which may be made of a nonelectrically conductive material, such as plastic. The drive shaft assembly components (including the main drive shaft 3080 and secondary drive shaft 3082) inside the proximate and distal closure tubes 3072, 3074 may also be made of a nonelectrically conductive material, such as plastic. Further, components of end effector 3016 (such as the anvil 3028 and the channel 3026) may be electrically coupled to (or in direct or indirect electrical contact with) the distal closure tube 3074 such that they may also serve as part of the antenna. Further, the transponder 3212, 3264 could be positioned such that it is electrically insulated from the components of the shaft 3014 and end effector 3016 serving as the antenna. For example, as discussed above, the transponder 3212, 3264 may be positioned in the staple cartridge 3038, which may be made of a nonelectrically conductive material, such as plastic. Because the distal end of the shaft 3014 (such as the distal end of the distal closure tube 3074) and the portions of the end effector 3016 serving as the antenna may be relatively close in distance to the transponder 3212, 3264, the power for the transmitted signals may be controlled such that interference with other systems in the use environment of the instrument 3010 is reduced or minimized

[0241] In such an embodiment, as shown in FIG. 59, the control unit 3196 may be electrically coupled to the shaft 3014 of the instrument 3010, such as to the proximate closure tube 3072, by a conductive link 3272 (e.g., a wire). Portions of the outer shaft 3014, such as the closure tubes 3072, 3074, may therefore act as part of an antenna for the control unit 3196 by transmitting signals to the transponder 3212, 3264 and receiving signals transmitted by the transponder 3212, 3264. Signals received by the control unit 3196 may be demodulated by the demodulator 3204 and decoded by the decoder 3206, as described above.

[0242] To transmit data signals to or from the transponder 3212, 3264 in the end effector 3016, the link 3272 may connect the control unit 3196 to components of the shaft 3014 of the instrument 3010, such as the proximate closure tube 3072, which may be electrically connected to the distal closure tube 3074. The distal closure tube 3074 is preferably electrically insulated from the transponder 3212, 3264, which may be positioned in the plastic staple cartridge 3038. As mentioned before, components of the end effector 3016, such as the channel 3026 and the anvil 3028, may be conductive and in electrical contact with the distal closure tube 3074 such that they, too, may serve as part of the antenna.

[0243] With the shaft 3014 acting as the antenna for the control unit 3196, the control unit 3196 can communicate with the transponder 3212, 3264 in the end effector 3016 without a hardwired connection. In addition, because the distance between shaft 3014 and the transponder 3212, 3264 is fixed and known, the power levels could be optimized to thereby minimize interference with other systems in the use environment of the instrument 3010.

[0244] In another embodiment, the components of the shaft 3014 and/or the end effector 3016 may serve as an antenna for the transponder 3212, 3264. In such an embodiment, the transponder 3212, 3264 is electrically connected to the shaft 3014 (such as to distal closure tube 3074, which may be electrically connected to the proximate closure tube 3072) and the control unit 3196 is insulated from the shaft 3014. For example, the transponder 3212, 3264 could be connected to a conductive component of the end effector 3016 (such as the channel 3026), which in turn may be connected to conductive components of the shaft (e.g., the closure tubes 3072, 3074). Alternatively, the end effector 3016 may include a wire (not shown) that connects the transponder 3212, 3264 the distal closure tube 3074.

[0245] FIGS. 64 and 65 depict a surgical cutting and fastening instrument 4010 according to various embodiments of the present invention. The illustrated embodiment is an endoscopic instrument and, in general, the embodiments of the instrument 4010 described herein are endoscopic surgical cutting and fastening instruments. It should be noted, however, that according to other embodiments of the present invention, the instrument may be a non-endoscopic surgical cutting and fastening instrument, such as a laparoscopic instrument.

[0246] The surgical instrument 4010 depicted in FIGS. 64 and 65 comprises a handle 4012, a shaft 4014, and an articulating end effector 4016 pivotally connected to the shaft 4014 at an articulation pivot 4018. An articulation control 4020 may be provided adjacent to the handle 4012 to effect rotation of the end effector 4016 about the articulation pivot 4018. In the illustrated embodiment, the end effector 4016 is configured to act as an endocutter for clamping, severing and stapling tissue, although, in other embodiments, different types of end effectors may be used, such as end effectors for other types of surgical devices, such as graspers, cutters, staplers, clip appliers, access devices, drug/gene therapy devices, ultrasound, RF or laser devices, etc.

[0247] The handle 4012 of the instrument 4010 may include a closure trigger 4022 and a firing trigger 4024 for actuating the end effector 4016. It will be appreciated that instruments having end effectors directed to different surgical tasks may have different numbers or types of triggers or other suitable controls for operating the end effector 4016. The end effector 4016 is shown separated from the handle 4012 by a preferably elongate shaft 4014. In one embodiment, an operator of the instrument 4010 may articulate the end effector 4016 relative to the shaft 4014 by utilizing the articulation control 4020 as described in more detail in U.S. patent application Ser. No. 11/329,020 entitled SURGICAL INSTRUMENT HAVING AN ARTICULATING END EFFECTOR, now U.S. Pat. No. 7,670,334, which is incorporated herein by reference.

[0248] The end effector 4016 includes in this example, among other things, a staple channel 4026 and a pivotally translatable clamping member, such as an anvil 4028, which are maintained at a spacing that assures effective stapling and severing of tissue clamped in the end effector 4016. The handle 4012 includes a pistol grip 4030 towards which a closure trigger 4022 is pivotally drawn by the operator to cause clamping or closing of the anvil 4028 toward the staple channel 4026 of the end effector 4016 to thereby clamp tissue positioned between the anvil 4028 and the channel 4026. The firing trigger 4024 is farther outboard of the closure trigger 4022. Once the closure trigger 4022 is locked in the closure position as further described below, the firing trigger 4024 may rotate slightly toward the pistol grip 4030 so that it can be reached by the operator using one hand. The operator may then pivotally draw the firing trigger 4024 toward the pistol grip 4030 to cause the stapling and severing of clamped tissue in the end effector 4016. In other embodiments, different types of clamping members besides the anvil 4028 may be used, such as, for example, an opposing jaw, etc.

[0249] It will be appreciated that the terms “proximal” and “distal” are used herein with reference to an operator gripping the handle 4012 of an instrument 4010. Thus, the end effector 4016 is distal with respect to the more proximal handle 4012. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical” and “horizontal” are used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.

[0250] The closure trigger 4022 may be actuated first. Once the operator is satisfied with the positioning of the end effector 4016, the operator may draw back the closure trigger 4022 to its fully closed, locked position proximate to the pistol grip 4030. The firing trigger 4024 may then be actuated. The firing trigger 4024 returns to the open position (shown in FIGS. 64 and 65) when the operator removes pressure, as described more fully below. A release button 4032 on the handle 4012, when depressed, may release the locked closure trigger 4022. Various configurations for locking and unlocking the closure trigger 4022 using the release button 4032 are described in U.S. patent application Ser. No. 11/343,573 entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH LOADING FORCE FEEDBACK, now U.S. Pat. No. 7,416,101, which is incorporated herein by reference.

[0251] FIG. 66A is an exploded view of the end effector 4016 according to various embodiments. As shown in the illustrated embodiment, the end effector 4016 may include, in addition to the previously-mentioned channel 4026 and anvil 4028, a cutting instrument 4034, a sled 4036, a staple cartridge 4038 that is removably seated (e.g., installed) in the channel 4026, and a helical screw shaft 4040, and FIG. 66B is a perspective view of the cutting instrument of FIG. 66A.

[0252] The anvil 4028 may be pivotably opened and closed at a pivot point 4042 connected to the proximate end of the channel 4026. The anvil 4028 may also include a tab 4044 at its proximate end that is inserted into a component of the mechanical closure system (described further below) to open and close the anvil 4028. When the closure trigger 4022 is actuated, that is, drawn in by an operator of the instrument 4010, the anvil 4028 may pivot about the pivot point 4042 into the clamped or closed position. If clamping of the end effector 4016 is satisfactory, the operator may actuate the firing trigger 4024, which, as explained in more detail below, causes the cutting instrument 4034 to travel longitudinally along the channel 4026.

[0253] As shown, the cutting instrument 4034 includes upper guide pins 4046 that enter an anvil slot 4048 in the anvil 4028 to verify and assist in maintaining the anvil 4028 in a closed state during staple formation and severing. Spacing between the channel 4026 and anvil 4028 is further maintained by the cutting instrument 4034 by having middle pins 4050 slide along the top surface of the channel 4026 while a bottom foot 4052 opposingly slides along the undersurface of the channel 4026, guided by a longitudinal opening 4054 in the channel 4026. A distally presented cutting surface 4056 between the upper guide pins 4046 and middle pins 4050 severs clamped tissue while distally-presented surface 4058 actuates the staple cartridge 4038 by progressively driving the sled 4036 from an unfired position to a fired position. Actuation of the staple cartridge 4038 causes staple drivers 4060 to cam upwardly, driving staples 4062 out of upwardly open staple holes 4064 formed in the staple cartridge 4038. The staples 4062 are subsequently formed against a staple forming undersurface 4066 of the anvil 4028. A staple cartridge tray 4068 encompasses from the bottom the other components of the staple cartridge 4038 to hold them in place. The staple cartridge tray 4068 includes a rearwardly open slot 4070 that overlies the longitudinal opening 4054 in the channel 4026. A lower surface of the staple cartridge 4038 and an upward surface of the channel 4026 form a firing drive slot 4200 (FIG. 69) through which the middle pins 4050 pass during distal and proximal movement of the cutting instrument 4034. The sled 4036 may be an integral component of the staple cartridge 4038 such that when the cutting instrument 4034 retracts following the cutting operation, the sled 4036 does not retract. U.S. Pat. No. 6,978,921, entitled SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRING MECHANISM, which is incorporated herein by reference, provides more details about such two-stroke cutting and fastening instruments.

[0254] It should be noted that although the embodiments of the instrument 4010 described herein employ an end effector 4016 that staples the severed tissue, in other embodiments different techniques for fastening or sealing the severed tissue may be used. For example, end effectors that use RF energy or adhesives to fasten the severed tissue may also be used. U.S. Pat. No. 5,709,680 entitled ELECTROSURGICAL HEMOSTATIC DEVICE, and U.S. Pat. No. 5,688,270 entitled ELECTROSURGICAL HEMOSTATIC DEVICE WITH RECESSED AND/OR OFFSET ELECTRODES, both of which are incorporated herein by reference, disclose cutting instruments that uses RF energy to fasten the severed tissue. U.S. patent application Ser. No. 11/267,811 entitled SURGICAL STAPLING INSTRUMENTS STRUCTURED FOR DELIVERY OF MEDICAL AGENTS, now U.S. Pat. No. 7,673,783, and U.S. patent application Ser. No. 11/267,383 entitled SURGICAL STAPLING INSTRUMENTS STRUCTURED FOR PUMP-ASSISTED DELIVERY OF MEDICAL AGENTS, now U.S. Pat. No. 7,607,557, both of which are also incorporated herein by reference, disclose cutting instruments that uses adhesives to fasten the severed tissue. Accordingly, although the description herein refers to cutting/stapling operations and the like, it should be recognized that this is an exemplary embodiment and is not meant to be limiting. Other tissue-fastening techniques may also be used.

[0255] FIGS. 67 and 68 are exploded views and FIG. 69 is a side view of the end effector 4016 and shaft 4014 according to various embodiments. As shown in the illustrated embodiment, the shaft 4014 may include a proximate closure tube 4072 and a distal closure tube 4074 pivotably linked by a pivot links 4076. The distal closure tube 4074 includes an opening 4078 into which the tab 4044 on the anvil 4028 is inserted in order to open and close the anvil 4028, as further described below. Disposed inside the closure tubes 4072, 4074 may be a proximate spine tube 4079. Disposed inside the proximate spine tube 4079 may be a main rotational (or proximate) drive shaft 4080 that communicates with a secondary (or distal) drive shaft 4082 via a bevel gear assembly 4084. The secondary drive shaft 4082 is connected to a drive gear 4086 that engages a proximate drive gear 4088 of the helical screw shaft 4040. The vertical bevel gear 4084b may sit and pivot in an opening 4090 in the distal end of the proximate spine tube 4079. A distal spine tube 4092 may be used to enclose the secondary drive shaft 4082 and the drive gears 4086, 4088. Collectively, the main drive shaft 4080, the secondary drive shaft 4082, and the articulation assembly (e.g., the bevel gear assembly 4084a-c) are sometimes referred to herein as the “main drive shaft assembly.”

[0256] A bearing 4094 (FIG. 69) positioned at a distal end of the staple channel 4026 receives the helical screw shaft 4040, allowing the helical screw shaft 4040 to freely rotate with respect to the channel 4026. The helical screw shaft 4040 may interface a threaded opening (not shown) of the cutting instrument 4034 such that rotation of the helical screw shaft 4040 causes the cutting instrument 4034 to translate distally or proximately (depending on the direction of the rotation) through the staple channel 4026. Accordingly, when the main drive shaft 4080 is caused to rotate by actuation of the firing trigger 4024 (as explained in further detail below), the bevel gear assembly 4084a-c causes the secondary drive shaft 4082 to rotate, which in turn, because of the engagement of the drive gears 4086, 4088, causes the helical screw shaft 4040 to rotate, which causes the cutting instrument 4034 to travel longitudinally along the channel 4026 to cut any tissue clamped within the end effector 4016. The sled 4036 may be made of, for example, plastic, and may have a sloped distal surface. As the sled 4036 traverses the channel 4026, the sloped distal surface may cam the staple drivers 4060 upward, which in turn push up or drive the staples 4062 in the staple cartridge 4038 through the clamped tissue and against the staple forming undersurface 4066 of the anvil 4028, thereby stapling the severed tissue. When the cutting instrument 4034 is retracted, the cutting instrument 4034 and the sled 4036 may become disengaged, thereby leaving the sled 4036 at the distal end of the channel 4026.

[0257] FIGS. 70-73 illustrate an exemplary embodiment of a motor-driven endocutter, and in particular the handle 4012 thereof, that provides operator-feedback regarding the deployment and loading force of the cutting instrument 4034 in the end effector 4016. In addition, the embodiment may use power provided by the operator in retracting the firing trigger 4024 to power the device (a so-called “power assist” mode). As shown in the illustrated embodiment, the handle 4012 includes exterior lower side pieces 4096, 4098 and exterior upper side pieces 4100, 4102 that fit together to form, in general, the exterior of the handle 4012. A battery 4104 may be provided in the pistol grip portion 4030 of the handle 4012. The battery 4104 may be constructed according to any suitable construction or chemistry including, for example, a Li-ion chemistry such as LiCoO₂ or LiNiO₂, a Nickel Metal Hydride chemistry, etc. The battery 4104 powers a motor 4106 disposed in an upper portion of the pistol grip portion 4030 of the handle 4012. According to various embodiments, the motor 4106 may be a DC brushed driving motor having a maximum rotation of approximately 5000 to 100,000 RPM. The motor 4106 may drive a 90-degree bevel gear assembly 4108 comprising a first bevel gear 4110 and a second bevel gear 4112. The bevel gear assembly 4108 may drive a planetary gear assembly 4114. The planetary gear assembly 4114 may include a pinion gear 4116 connected to a drive shaft 4118. The pinion gear 4116 may drive a mating ring gear 4120 that drives a helical gear drum 4122 via a drive shaft 4124. A ring 4126 may be threaded on the helical gear drum 4122. Thus, when the motor 4106 rotates, the ring 4126 is caused to travel along the helical gear drum 4122 by means of the interposed bevel gear assembly 4108, planetary gear assembly 4114 and ring gear 4120.

[0258] The handle 4012 may also include a run motor sensor 4128 in communication with the firing trigger 4024 to detect when the firing trigger 4024 has been drawn in (or “closed”) toward the pistol grip portion 4030 of the handle 4012 by the operator to thereby actuate the cutting/stapling operation by the end effector 4016. The sensor 4128 may be a proportional sensor such as, for example, a rheostat or variable resistor. When the firing trigger 4024 is drawn in, the sensor 4128 detects the movement, and sends an electrical signal indicative of the voltage (or power) to be supplied to the motor 4106. When the sensor 4128 is a variable resistor or the like, the rotation of the motor 4106 may be generally proportional to the amount of movement of the firing trigger 4024. That is, if the operator only draws or closes the firing trigger 4024 in a little bit, the rotation of the motor 4106 is relatively low. When the firing trigger 4024 is fully drawn in (or in the fully closed position), the rotation of the motor 4106 is at its maximum. In other words, the harder the operator pulls on the firing trigger 4024, the more voltage is applied to the motor 4106, causing a greater rate of rotation. In another embodiment, for example, a microcontroller (e.g., the microcontroller 4250 of FIG. 92) may output a PWM control signal to the motor 4106 based on the input from the sensor 4128 in order to control the motor 4106.

[0259] The handle 4012 may include a middle handle piece 4130 adjacent to the upper portion of the firing trigger 4024. The handle 4012 also may comprise a bias spring 4132 connected between posts on the middle handle piece 4130 and the firing trigger 4024. The bias spring 4132 may bias the firing trigger 4024 to its fully open position. In that way, when the operator releases the firing trigger 4024, the bias spring 4132 will pull the firing trigger 4024 to its open position, thereby removing actuation of the sensor 4128, thereby stopping rotation of the motor 4106. Moreover, by virtue of the bias spring 4132, any time an operator closes the firing trigger 4024, the operator will experience resistance to the closing operation, thereby providing the operator with feedback as to the amount of rotation exerted by the motor 4106. Further, the operator could stop retracting the firing trigger 4024 to thereby remove force from the sensor 4128, to thereby stop the motor 4106. As such, the operator may stop the deployment of the end effector 4016, thereby providing a measure of control of the cutting/fastening operation to the operator.

[0260] The distal end of the helical gear drum 4122 includes a distal drive shaft 4134 that drives a ring gear 4136, which mates with a pinion gear 4138. The pinion gear 4138 is connected to the main drive shaft 4080 of the main drive shaft assembly. In that way, rotation of the motor 4106 causes the main drive shaft assembly to rotate, which causes actuation of the end effector 4016, as described above.

[0261] The ring 4126 threaded on the helical gear drum 4122 may include a post 4140 that is disposed within a slot 4142 of a slotted arm 4144. The slotted arm 4144 has an opening 4146 its opposite end 4148 that receives a pivot pin 4150 that is connected between the handle exterior side pieces 4096, 4098. The pivot pin 4150 is also disposed through an opening 4152 in the firing trigger 4024 and an opening 4154 in the middle handle piece 4130.

[0262] In addition, the handle 4012 may include a reverse motor (or end-of-stroke) sensor 4156 and a stop motor (or beginning-of-stroke) sensor 4158. In various embodiments, the reverse motor sensor 4156 may be a normally-open limit switch located at the distal end of the helical gear drum 4122 such that the ring 4126 threaded on the helical gear drum 4122 contacts and closes the reverse motor sensor 4156 when the ring 4126 reaches the distal end of the helical gear drum 4122. The reverse motor sensor 4156, when closed, sends a signal to the motor 4106 to reverse its rotation direction, thereby retracting the cutting instrument 4034 of the end effector 4016 following a cutting operation.

[0263] The stop motor sensor 4158 may be, for example, a normally-closed limit switch. In various embodiments, it may be located at the proximate end of the helical gear drum 4122 so that the ring 4126 opens the switch 4158 when the ring 4126 reaches the proximate end of the helical gear drum 4122.

[0264] In operation, when an operator of the instrument 4010 pulls back the firing trigger 4024, the sensor 4128 detects the deployment of the firing trigger 4024 and sends a signal to the motor 4106 to cause forward rotation of the motor 4106 at, for example, a rate proportional to how hard the operator pulls back the firing trigger 4024. The forward rotation of the motor 4106 in turn causes the ring gear 4120 at the distal end of the planetary gear assembly 4114 to rotate, thereby causing the helical gear drum 4122 to rotate, causing the ring 4126 threaded on the helical gear drum 4122 to travel distally along the helical gear drum 4122. The rotation of the helical gear drum 4122 also drives the main drive shaft assembly as described above, which in turn causes deployment of the cutting instrument 4034 in the end effector 4016. That is, the cutting instrument 4034 and sled 4036 are caused to traverse the channel 4026 longitudinally, thereby cutting tissue clamped in the end effector 4016. Also, the stapling operation of the end effector 4016 is caused to happen in embodiments where a stapling-type end effector is used.

[0265] By the time the cutting/stapling operation of the end effector 4016 is complete, the ring 4126 on the helical gear drum 4122 will have reached the distal end of the helical gear drum 4122, thereby causing the reverse motor sensor 4156 to be actuated, which sends a signal to the motor 4106 to cause the motor 4106 to reverse its rotation. This in turn causes the cutting instrument 4034 to retract, and also causes the ring 4126 on the helical gear drum 4122 to move back to the proximate end of the helical gear drum 4122.

[0266] The middle handle piece 4130 includes a backside shoulder 4160 that engages the slotted arm 4144 as best shown in FIGS. 71 and 72. The middle handle piece 4130 also has a forward motion stop 4162 that engages the firing trigger 4024. The movement of the slotted arm 4144 is controlled, as explained above, by rotation of the motor 4106. When the slotted arm 4144 rotates CCW as the ring 4126 travels from the proximate end of the helical gear drum 4122 to the distal end, the middle handle piece 4130 will be free to rotate CCW. Thus, as the operator draws in the firing trigger 4024, the firing trigger 4024 will engage the forward motion stop 4162 of the middle handle piece 4130, causing the middle handle piece 4130 to rotate CCW. Due to the backside shoulder 4160 engaging the slotted arm 4144, however, the middle handle piece 4130 will only be able to rotate CCW as far as the slotted arm 4144 permits. In that way, if the motor 4106 should stop rotating for some reason, the slotted arm 4144 will stop rotating, and the operator will not be able to further draw in the firing trigger 4024 because the middle handle piece 4130 will not be free to rotate CCW due to the slotted arm 4144.

[0267] FIGS. 74 and 75 illustrate two states of a variable sensor that may be used as the run motor sensor 4128 according to various embodiments of the present invention. The sensor 4128 may include a face portion 4164, a first electrode (A) 4166, a second electrode (B) 4168, and a compressible dielectric material 4170 (e.g., EAP) between the electrodes 4166, 4168. The sensor 4128 may be positioned such that the face portion 4164 contacts the firing trigger 4024 when retracted. Accordingly, when the firing trigger 4024 is retracted, the dielectric material 4170 is compressed, as shown in FIG. 75, such that the electrodes 4166, 4168 are closer together. Since the distance “b” between the electrodes 4166, 4168 is directly related to the impedance between the electrodes 4166, 4168, the greater the distance the more impedance, and the closer the distance the less impedance. In that way, the amount that the dielectric material 4170 is compressed due to retraction of the firing trigger 4024 (denoted as force “F” in FIG. 75) is proportional to the impedance between the electrodes 4166, 4168, which can be used to proportionally control the motor 4106.

[0268] Components of an exemplary closure system for closing (or clamping) the anvil 4028 of the end effector 4016 by retracting the closure trigger 4022 are also shown in FIGS. 70-73. In the illustrated embodiment, the closure system includes a yoke 4172 connected to the closure trigger 4022 by a pin 4174 that is inserted through aligned openings in both the closure trigger 4022 and the yoke 4172. A pivot pin 4176, about which the closure trigger 4022 pivots, is inserted through another opening in the closure trigger 4022 which is offset from where the pin 4174 is inserted through the closure trigger 4022. Thus, retraction of the closure trigger 4022 causes the upper part of the closure trigger 4022, to which the yoke 4172 is attached via the pin 4174, to rotate CCW. The distal end of the yoke 4172 is connected, via a pin 4178, to a first closure bracket 4180. The first closure bracket 4180 connects to a second closure bracket 4182. Collectively, the closure brackets 4180, 4182 define an opening in which the proximal end of the proximate closure tube 4072 (see FIG. 67) is seated and held such that longitudinal movement of the closure brackets 4180, 4182 causes longitudinal motion by the proximate closure tube 4072. The instrument 4010 also includes a closure rod 4184 disposed inside the proximate closure tube 4072. The closure rod 4184 may include a window 4186 into which a post 4188 on one of the handle exterior pieces, such as exterior lower side piece 4096 in the illustrated embodiment, is disposed to fixedly connect the closure rod 4184 to the handle 4012. In that way, the proximate closure tube 4072 is capable of moving longitudinally relative to the closure rod 4184. The closure rod 4184 may also include a distal collar 4190 that fits into a cavity 4192 in proximate spine tube 4079 and is retained therein by a cap 4194 (see FIG. 67).

[0269] In operation, when the yoke 4172 rotates due to retraction of the closure trigger 4022, the closure brackets 4180, 4182 cause the proximate closure tube 4072 to move distally (i.e., away from the handle 4012 of the instrument 4010), which causes the distal closure tube 4074 to move distally, which causes the anvil 4028 to rotate about the pivot point 4042 into the clamped or closed position. When the closure trigger 4022 is unlocked from the locked position, the proximate closure tube 4072 is caused to slide proximally, which causes the distal closure tube 4074 to slide proximally, which, by virtue of the tab 4044 being inserted in the opening 4078 of the distal closure tube 4074, causes the anvil 4028 to pivot about the pivot point 4042 into the open or unclamped position. In that way, by retracting and locking the closure trigger 4022, an operator may clamp tissue between the anvil 4028 and channel 4026, and may unclamp the tissue following the cutting/stapling operation by unlocking the closure trigger 4022 from the locked position.

[0270] According to various embodiments, the instrument 4010 may include an interlock for preventing instrument 4010 operation when the staple cartridge 4038 is not installed in the channel 4026, or when the staple cartridge 4038 is installed in the channel 4026 but spent. Operation of the interlock is twofold. First, in the absence of an unspent staple cartridge 4038 within the channel 4026, the interlock operates to mechanically block distal advancement of the cutting instrument 4034 through the channel 4026 in response to actuation of the firing trigger 4024. Using suitable electronics disposed within the handle 4012, the interlock next detects the increase in current through the motor 4106 resulting from the immobilized cutting instrument 4034 and consequently interrupts current to the motor 4106. Advantageously, the interlock eliminates the need for electronic sensors in the end effector 4016, thus simplifying instrument design. Moreover, because the magnitude and duration of mechanical blocking force needed to produce the detected increase in motor current is significantly less than that which would be exerted if only a conventional mechanical interlock was used, physical stresses experienced by instrument components are reduced.

[0271] According to various embodiments, the interlock may include (1) a blocking mechanism to prevent actuation of the cutting instrument 4034 by the motor 4106 when an unspent staple cartridge 4038 is not installed in the channel 4026, and (2) a lockout circuit to detect the current through the motor 4106 and to interrupt the current through the motor 4106 based on the sensed current.

[0272] FIG. 94 is a flow diagram of the process implemented by the interlock according to various embodiments. At step 4264, the actuation of the cutting instrument 4034 by the motor 4106 is mechanically blocked by the blocking mechanism in the absence of an unspent staple cartridge 4038 within the channel 4026. As discussed below, the blocking mechanism may include components or features of conventional mechanical interlocks.

[0273] At step 4266, the current through the motor 4106 resulting from the blocked actuation of the cutting instrument 4034 is detected by the lockout circuit. As discussed below, detection of the current may include, for example, the steps of sensing the motor current, generating a signal representative of the sensed motor current, and comparing the generated signal to a threshold signal.

[0274] At step 4268, the current through the motor 4106 is interrupted based on the detected current. Interrupting the current may include, for example, interrupting the current when the result of the comparison at step 4266 indicates that the generated signal exceeds the threshold signal. Interrupting the current through the motor 4106 may further include interrupting the current based on a position of the cutting instrument 4034.

[0275] According to various embodiments, the blocking mechanism of the interlock may include features similar or identical to those of conventional mechanical interlocks for physically blocking advancement of the cutting instrument 4034 in the absence of an unspent staple cartridge 4038 within the channel 4026. FIG. 76 illustrates a blocking mechanism 4196 according to one embodiment. As shown, the blocking mechanism 4196 may comprise a pair of spring fingers 4198 positioned in the channel 4026. In particular, the spring fingers 4196 may raise up to block the middle pins 4050 of the cutting instrument 4034 when the sled 4036 (not shown in FIG. 76) is not present in an unfired position at the proximal end of the channel 4026, such as when the staple cartridge 4038 is not installed or when the staple cartridge 4038 is installed but spent. Although two spring fingers 4198 are shown, it will be appreciated that more or fewer spring fingers 4198 may be used instead.

[0276] FIGS. 77-80 depict the operation of the spring fingers 4198 sequentially as the instrument 4010 is fired. In FIG. 77, an unspent staple cartridge 4038 has been inserted into the channel 4026. The presence of the sled 4036 in its unfired position depresses the spring fingers 4198 such that the firing drive slot 4200 through which the middle pins 4050 will pass is unimpeded.

[0277] In FIG. 78, firing of the staple cartridge 4038 has commenced, with the sled 4036 and the middle pins 4050 of the cutting instrument 4034 having distally traversed off of the spring fingers 4198, which then spring up into the firing drive slot 4200.

[0278] In FIG. 79, the staple cartridge 4038 is now spent with the sled 4036 fully driven distally and no longer depicted. The cutting instrument 4034 is being retracted proximally. Since the spring fingers 4198 pivot from a more distal point, the middle pins 4050 of the cutting instrument 4034 are able to ride up onto the spring fingers 4198 during retraction, causing them to be depressed out of the firing drive slot 4200.

[0279] In FIG. 80, the cutting instrument 4034 is fully retracted and now confronts the non-depressed pair of spring fingers 4198 to prevent distal movement. The blocking mechanism 4196 thereby remains activated until an unspent staple cartridge 4038 is installed in the channel 4026.

[0280] FIG. 81 depicts a blocking mechanism 4202 according to another embodiment. The blocking mechanism 4202, which is disclosed in U.S. Pat. No. 7,044,352 referenced above, includes a pair of hooks 4204 having ramped ends 4206 distally placed with regard to attachment devices 4208. The attachment devices 4208 are inserted through apertures 4210 in the channel 4026, thereby springedly attaching the hooks 4204 to the channel 4026. The ramped ends 4206 lie above a hook recess 4212 defined in the channel 4026. Thus, when each ramped end 4206 is contacted by the sled 4036 of an unspent staple cartridge 4038 (not shown in FIG. 81), the ramped ends 4206 are depressed into the hook recess 4212, thereby clearing the way for the middle pins 4050 of the cutting instrument 4034 to move distally through the firing drive slot 4200 so that the staple cartridge 4038 may be actuated. A thin shaft 4214 coupling the attachment devices 4208 respectively to the ramped end 4206 of each hook 4204 resiliently responds to absence of the sled 4036, as depicted, wherein the ramped ends 4206 return to impede the firing drive slot 4200 to block the retracted middle pins 4050 of the cutting instrument 4034. Although two hooks 4204 are shown, it will be appreciated that more or fewer hooks 4204 may be used instead.

[0281] FIGS. 82-85 depict the sequence of operation of the hooks 4204. In FIG. 82, the staple cartridge 4038 is unspent so that the distally positioned sled 4036 depresses the ramped ends 4206 into the hook recess 4212, allowing the middle pins 4050 of the cutting instrument 4034 to move distally through the firing drive slot 4200 during firing, as depicted in FIG. 83. With the sled 4036 and middle pins 4050 distally removed with respect to the blocking mechanism 4202, the ramped ends 4206 resiliently raise out of the hook recess 4212 to occupy the firing drive slot 4200.

[0282] In FIG. 84, the cutting instrument 4034 is being retracted to the point of contacting the ramped ends 4206 of the hooks 4204. Since the distal end of the ramped ends 4206 is lower than the proximal part of the ramped ends 4206, the middle pins 4050 of the cutting instrument 4034 ride over the ramped ends 4206, forcing them down into the hook recess 4212 until the middle pins 4050 are past the ramped ends 4206, as depicted in FIG. 85, wherein the ramped ends 4206 resiliently spring back up to block the middle pins 4050. Thus, the cutting instrument 4034 is prevented from distal movement until an unspent staple cartridge 4038 is installed in the channel 4026.

[0283] FIG. 86 depicts a blocking mechanism 4216 according to yet another embodiment. The blocking mechanism 4216 is integrally formed with the staple cartridge 4038 and includes proximally projecting blocking members 4218 resiliently positioned above the sled 4036 (not shown in FIG. 86). In particular, the blocking members 4218 each reside within a downward and proximally opening cavity 4220. Each blocking member 4218 includes a leaf spring end 4222 that is held within the cavity 4220.

[0284] The cavities 4220 are vertically aligned and spaced and parallel about a proximally presented vertical slot 4224 in the staple cartridge 4038 through which the cutting surface 4056 (not shown in FIG. 86) passes. The staple cartridge 4038 also includes slots 4226 that longitudinally pass through the staple cartridge 4038, being open from a portion of a proximal and underside of the staple cartridge 4038 to receive the sled 4036.

[0285] Each blocking member 4218 has a deflectable end 4228 having a ramped distal side 4227 and blocking proximal side 4229. The blocking members 4218 are shaped to reside within their respective cavities 4220 when depressed and to impede the distally moving middle pins 4050 of the cutting instrument 4034 when released.

[0286] FIGS. 87-90 depict the blocking mechanism 4216 sequentially as the instrument 4010 is fired. In FIG. 87, an unspent staple cartridge 4038 has been inserted into the channel 4026 with the sled 4036 depressing upward the deflectable ends 4228 so that the firing drive slot 4200 is unimpeded.

[0287] In FIG. 88, firing of the staple cartridge 4038 has commenced, with the sled 4036 and the middle pins 4050 of the cutting instrument 4034 having distally traversed past the deflectable ends 4228, which then spring down into the firing drive slot 4200.

[0288] In FIG. 89, the staple cartridge 4038 is now spent with the sled 4036 fully driven distally and no longer depicted. The cutting instrument 4034 is being retracted proximally. Since the deflectable ends 4228 pivot from a more distal point, the middle pins 4050 of the cutting instrument 4034 are able to ride under the ramped distal sides 4227 of the deflectable ends 4228 during retraction, causing them to be depressed up, out of the firing drive slot 4200.

[0289] In FIG. 90, the cutting instrument 4034 is fully retracted and the middle pints 4050 now confront the blocking proximal sides 4229 of the non-depressed (released) pair of deflectable ends 4228 to prevent distal movement. The blocking mechanism 4216 thereby remains activated until an unspent staple cartridge 4038 is installed in the channel 4026.

[0290] The blocking mechanisms 4196, 4202, 4216 of the above-discussed embodiments are provided by way of example only. It will be appreciated that other suitable blocking mechanisms may be used instead.

[0291] FIG. 91 is a schematic diagram of an electrical circuit 4231 of the instrument 4010 according to various embodiments of the present invention. In certain embodiments, the circuit 4231 may be housed within the handle 4012. In addition to the sensor 4128, sensors 4156, 4158 (depicted as a normally-open limit switch and a normally-closed limit switch, respectively), the battery 4104, and the motor 4106, the circuit 4231 may include a single-pole double-throw relay 4230, a single-pole single-throw relay 4232, a double-pole double-throw relay 4234, a current sensor 4236, a position sensor 4238, and a current detection module 4240. Relay 4232, the current sensor 4236, the position sensor 4238, and the current detection module 4240 collectively form a lockout circuit 4241. As described below, the lockout circuit 4241 operates to sense the current through the motor 4106 and to interrupt the current based upon the sensed current, thus “locking out” the instrument 4010 by disabling its operation.

[0292] As described above, sensor 4128 is activated when an operator pulls in the firing trigger 4024 after locking the closure trigger 4022. When switch 4156 is open (indicating that the cutting/stapling operation of the end effector 4016 is not yet complete), coil 4242 of relay 4230 is de-energized, thus forming a conductive path between the battery 4104 and relay 4232 via a normally-closed contact of relay 4230. Coil 4244 of relay 4232 is controlled by the current detection module 4240 and the position sensor 4238 as described below. When coil 4244 is de-energized and coil 4242 is de-energized, a conductive path between the battery 4104 and a normally-closed contact of relay 4234 is formed. Relay 4234 controls the rotational direction of the motor 4106 based on the states of switches 4156, 4158. When switch 4156 is open and switch 4158 is closed (indicating that the cutting instrument 4034 has not yet fully deployed distally), coil 4246 of relay 4234 is de-energized. Accordingly, when coils 4242, 4244, 4246 are collectively de-energized, current from the battery 4104 flows through the motor 4106 via the normally-closed contacts of relay 4234 and causes the forward rotation of the motor 4106, which in turn causes distal deployment of the cutting instrument 4034 as described above.

[0293] When switch 4156 is closed (indicating that the cutting instrument 4034 has fully deployed distally), coil 4242 of relay 4230 is energized, and coil 4246 of relay 4234 is energized via a normally-open contact of relay 4230. Accordingly, current now flows to the motor 4106 via normally-open contacts of relays 4230, 4234, thus causing reverse rotation of the motor 4106 which in turn causes the cutting instrument 4034 to retract from its distal position and switch 4156 to open. Coil 4242 of relay 4230 remains energized until limit switch 4158 is opened, indicating the complete retraction of the cutting instrument 4034.

[0294] The magnitude of current through the motor 4106 during its forward rotation is indicative of forces exerted upon the cutting instrument 4034 during its deployment. As described above, the absence of an unspent staple cartridge 4038 in the channel 4026 (e.g., the presence of a spent staple cartridge 4038 or the absence of a staple cartridge 4038 altogether) results in activation of the blocking mechanism 4196, 4202, 4216 such that distal movement of the cutting instrument 4034 is prevented. The resistive force exerted by the blocking mechanism 4196, 4202, 4216 against the cutting instrument 4034 causes an increase in motor torque, thus causing motor current to increase to a level that is measurably greater than that present during a cutting and stapling operation. Accordingly, by sensing the current through the motor 4106, the lockout circuit 4241 may differentiate between deployment of the cutting instrument 4034 when an unspent cartridge 4038 is installed in the channel 4026 versus deployment of the cutting instrument 4034 when an unspent cartridge 4038 is absent from the channel 4026.

[0295] The current sensor 4236 may be coupled to a path of the circuit 4231 that conducts current to the motor 4106 during its forward rotation. The current sensor 4236 may be any current sensing device (e.g., a shunt resistor, a Hall effect current transducer, etc.) suitable for generating a signal (e.g., a voltage signal) representative of sensed motor current. The generated signal may be input to the current detection module 4240 for processing therein, as described below.

[0296] According to various embodiments, the current detection module 4240 may be configured for comparing the signal generated by the current sensor 4236 to a threshold signal (e.g., a threshold voltage signal) to determine if the blocking mechanism 4196, 4202, 4216 has been activated. For a given instrument 4010, a suitable value of the threshold signal may be empirically determined a priori by, for example, measuring the peak signal generated by the current sensor 4236 when the cutting instrument 4034 is initially deployed (e.g., over the first 0.06 inches of its distal movement) during a cutting and stapling operation, and when the cutting instrument 4034 is deployed and encounters the activated blocking mechanism 4196, 4202, 4216. The threshold signal value may be selected to be less than the peak signal measured when the blocking mechanism 4196, 4202, 4216 is activated, but larger than the peak signal measured during a cutting and stapling operation.

[0297] In certain embodiments and as shown in FIG. 91, the current detection module 4240 may comprise a comparator circuit 4248 for receiving the threshold and current sensor 4236 signals and generating a discrete output based on a comparison of the received signals. For example, the comparator circuit 4248 may generate a 5 VDC output when the threshold signal is exceeded and a OVDC output when the threshold signal is not exceeded. The threshold signal may be generated, for example, using a suitable signal reference circuit (e.g., a voltage reference circuit) (not shown). The design and operation of the comparator circuit 4248 and signal reference circuit are well known in the art and are not described further herein.

[0298] The result of the threshold and current sensor 4236 signal comparison is primarily of interest during the initial deployment (e.g., during the first 0.06 inches of distal movement) of the cutting instrument 4034. Accordingly, the current detection module 4240 may limit the comparison based on the distal position of the cutting instrument 4034 as indicated by the position sensor 4238. The position sensor 4238 may be any type of position sensing device suitable for generating a signal indicative of a distal position of the cutting instrument 4034. In one embodiment and as shown in FIG. 91, for example, the position sensor 4238 may be a normally-open Hall effect position switch 4238 that is actuated based on its proximity to a magnet mounted on the ring 4126. The position switch 4238 may mounted within the handle 4012 and operate such that when the distal position of the cutting instrument 4034 (as indicated by the position of ring 4126) is within a pre-determined distance (e.g., distal position <0.06 inches) of its proximal-most position, the position switch 4238 is closed. Conversely, when the distal position of the cutting instrument 4034 exceeds the predetermined distance (e.g., distal position >0.06 inches), the position switch 4238 is opened. The position switch 4238 may be connected in series with the output of the comparator circuit 4248 to limit the comparison based on the position of the cutting instrument 4034. In this way, if the threshold signal is exceeded when the distal position of the cutting instrument 4034 is greater than pre-determined distance, the output of the position switch 4238 will remain at OVDC (according to the example presented above), regardless of the result of the comparison. It will be appreciated that other types of position sensors 4238 (e.g., mechanically-actuated limit switches, rotary potentiometers, etc.) may be used instead as an alternative to the Hall effect position switch 4238 described above. Additionally, it will be appreciated that auxiliary contacts (not shown) of switch 4158 may be used as an alternative to a separate position sensor 4238. In embodiments in which the position sensor 4238 does not include a switched output (e.g., when the position sensor 4238 is a potentiometer or other analog-based position sensor), additional processing of the position sensor 4236 output using, for example, a second comparator circuit, may be necessary.

[0299] As shown in FIG. 91, the output of the position switch 4238 may be connected to coil 4244 of relay 4232. Driver circuitry (not shown) between the position switch 4238 and the coil 4244 may be provided if necessary. Accordingly, if the signal generated by the current sensor 4236 exceeds the threshold signal (indicating activation of the blocking mechanism 4196, 4202, 4216 due to the absence of an unspent staple cartridge 4038), and the cutting instrument 4034 is within the predetermined distance of its proximal-most position, coil 4244 will be energized. This causes normally-closed switch of relay 4232 to open, thereby interrupting current flow to the motor 4106 and removing the resistive force exerted by the blocking mechanism 4196, 4202, 4216 upon the cutting instrument 4034. Importantly, because the blocking mechanism 4196, 4202, 4216 need only apply a mechanical blocking force sufficient to cause the threshold signal to be exceeded, the physical stresses exerted by the blocking mechanism 4196, 4202, 4216 are reduced in magnitude and duration compared to those that would be exerted if only conventional mechanical interlocks were used. Furthermore, because the interlock does not require electronic sensors in the end effector 4016, instrument design is simplified.

[0300] FIG. 92 is a schematic diagram of an electrical circuit 4249 of the instrument 4010 according to another other embodiment of the present invention in which a processor-based microcontroller 4250 is used to implement functionality of the lockout circuit 4241 described above. Although not shown for purposes of clarity, the microcontroller 4250 may include components well known in the microcontroller art such as, for example, a processor, a random access memory (RAM) unit, an erasable programmable read-only memory (EPROM) unit, an interrupt controller unit, timer units, analog-to-digital conversion (ADC) and digital-to-analog conversion (DAC) units, and a number of general input/output (I/O) ports for receiving and transmitting digital and analog signals. The current sensor 4236 and the position sensor 4238 may be connected to analog and digital inputs, respectively, of the microcontroller 4250, and the coil 4244 of relay 4232 may be connected to a digital output of the microcontroller 4250. It will be appreciated that in embodiments in which the output of the position sensor 4238 is an analog signal, the position sensor 4238 may be connected to an analog input instead. Additionally, although the circuit 4249 of FIG. 92 includes relays 4230, 4232, 4234, it will be appreciated that in other embodiments the relay switching functionality may be replicated using solid state switching devices, software, and combinations thereof. In certain embodiments, for example, instructions stored and executed in the microcontroller 4250 may be used to control solid state switched outputs of the microcontroller 4250. In such embodiments, switches 4156, 4158 may be connected to digital inputs of the microcontroller 4250.

[0301] FIG. 93 is a flow diagram of a process implemented by the microcontroller 4250 according to various embodiments. At step 4252, the microcontroller 4250 receives the signal generated by the current sensor 4236 via an analog input and converts the received signal into a corresponding digital current sensor signal.

[0302] At step 4254, values of the digital current sensor signal are compared to a digital threshold value stored within the microcontroller 4250. The digital threshold value may be, for example, a digitized representation of the threshold signal discussed above in connection with FIG. 91. If all values of the digital current sensor signal are less than the digital threshold value, the process terminates at step 4256. If a value of the digital current sensor signal exceeds the digital threshold value, the process proceeds to step 4258.

[0303] At step 4258, the position sensor 4238 input is processed to determine if the cutting instrument 4034 is within the predetermined distance of its proximal-most position. If the cutting instrument 4034 is not within the predetermined distance, the process is terminates at step 4260. If the cutting instrument 4034 is within the predetermined distance, the process proceeds to step 4262.

[0304] At step 4262, the digital output to corresponding to coil 4244 is energized, thus causing the normally closed contacts of relay 4232 to open, which in turn interrupts the current flow to the motor 4106.

[0305] Although embodiments described above compare the magnitude of the current sensor signal (or a digitized version thereof) to a threshold signal or value, it will be appreciated that other metrics for analyzing the current sensor signal may additionally or alternatively be used to differentiate between deployment of the cutting instrument 4034 when an unspent cartridge 4038 is installed in the channel 4026 versus deployment of the cutting instrument 4034 when an unspent cartridge 4038 is absent from the channel 4026. For example, the current detection module 4240 or the microcontroller 4250 may be configured to determine derivative and/or integral characteristics of the current sensor signal for comparison to corresponding thresholds signals or values. Additionally, in certain embodiments the current sensor signal may be processed prior to its analysis using, for example, signal conditioners and/or filters implementing one or more filter response functions (e.g., infinite impulse response functions).

[0306] The various embodiments of the present invention have been described above in connection with cutting-type surgical instruments. It should be noted, however, that in other embodiments, the inventive surgical instrument disclosed herein need not be a cutting-type surgical instrument, but rather could be used in any type of surgical instrument including remote sensor transponders. For example, it could be a non-cutting endoscopic instrument, a grasper, a stapler, a clip applier, an access device, a drug/gene therapy delivery device, an energy device using ultrasound, RF, laser, etc. In addition, the present invention may be in laparoscopic instruments, for example. The present invention also has application in conventional endoscopic and open surgical instrumentation as well as robotic-assisted surgery.

[0307] The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.

[0308] Although the present invention has been described herein in connection with certain disclosed embodiments, many modifications and variations to those embodiments may be implemented. For example, different types of end effectors may be employed. Also, where materials are disclosed for certain components, other materials may be used. The foregoing description and following claims are intended to cover all such modification and variations.

[0309] Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.