Motor-driven surgical cutting instrument with electric actuator directional control assembly

[0001] This application claims priority as a continuation to U.S. patent application Ser. No. 13/482,179, entitled “MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT WITH ELECTRIC ACTUATOR DIRECTIONAL CONTROL ASSEMBLY,” filed May 29, 2012, to be issued as U.S. Pat. No. 8,453,914 on Jun. 4, 2013, which is a continuation of U.S. patent application Ser. No. 12/647,100, entitled “MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT WITH ELECTRIC ACTUATOR DIRECTIONAL CONTROL ASSEMBLY,” filed Dec. 24, 2009, now U.S. Pat. No. 8,220,688 issued on Jun. 17, 2012, both of which are incorporated herein by reference in their entirety.

[0002] Surgical staplers are used to simultaneously make a longitudinal incision in tissue and apply lines of staples on opposing sides of the incision. Such instruments commonly include an end effector having 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—one on each side of the knife channel. 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 that, 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. Simultaneously, a cutting instrument (or knife) is drawn distally along the jaw member so that the clamped tissue is cut and fastened (e.g., stapled) at the same time.

[0003] An example of a surgical stapler suitable for endoscopic applications is described in published U.S. patent application Pub. No. 2004/0232196 A1, entitled, “Surgical stapling instrument having separate distinct closing and firing systems,” the disclosure of which is herein incorporated by reference in its entirety. In use, a clinician is able to close the jaw members of the stapler upon tissue to position the tissue prior to firing. Once the clinician has determined that the jaw members are properly gripping tissue, the clinician can then fire the surgical stapler, thereby severing and stapling the tissue. The simultaneous severing and stapling actions avoid complications that may arise when performing such actions sequentially with different surgical tools that respectively only sever or staple.

[0004] Motor-driven endocutters are known in the art. In such devices, an electric motor powers the cutting and fastening action of the instrument. It is also known to use an on-board battery, located in the handle of the instrument, to power the motor. Published U.S. Patent Application Publication No. 2007/0175952 A1, entitled “Motor-driven surgical cutting and fastening instrument with loading force feedback,” the disclosure of which is herein incorporated by reference in its entirety, describes one such motor-driven surgical instrument.

[0005] In motor-driven surgical instruments, it is sometimes preferable that the control circuit for controlling the operation of the motor does not include any integrated circuits (ICs) made of semiconductor material because it is often difficult, complicated, and expensive to sterilize a surgical instrument including ICs.

[0006] In one general aspect, the present invention is directed to a motor-driven surgical instrument having a control assembly for controlling a switch of the instrument. The switch may be part of the circuit that controls the motor or part of some other circuit in the instrument. In various embodiments, the surgical instrument comprises: (i) a handle; (ii) an end effector connected to the handle; (iii) an electric motor in the handle for powering the end effector; (iv) a motor control circuit connected to the motor for controlling the motor; (v) a drive member that is driven by the motor; and (vi) a slider. The motor control circuit comprises a plurality of switches, including a first switch with a moveable (e.g., depressible) actuator (e.g., plunger). The drive member, when driven by the motor, causes movement of a moveable component of the end effector, and the drive member comprises a first shoulder at a first position and a second shoulder at a second position. The slider comprises a first portion and a second portion. The first portion interfaces the drive member such that the slider is moveable in a direction of movement of the drive member when either the first shoulder or the second shoulder of the drive member engages the first portion of the slider. The second portion of the slider actuates the moveable actuator of the first switch when the drive member moves the slider to a first position relative to the first switch. In various embodiments, the switches of the control circuit are not embodied as a part of an IC. Thus in various embodiments, the motor control circuit does not comprise an integrated circuit. In various embodiments, the first switch controls the direction of rotation of the motor.

[0007] In various embodiments, the drive member may move longitudinally or rotationally when actuated by the motor. For example, in one embodiment, the drive member comprises a longitudinally moveable rack that has, on one side, teeth geared to a pinion that is rotated by the motor, and that defines a channel having the first and second shoulders on the other side of the rack. The first portion of the slider that interfaces with the drive member may comprises one or more tabs that extend into the channel. The second portion of the slider that actuates the switch may comprise a cantilevered arm.

[0008] In yet another general aspect, the motor control circuit comprises a switching circuit that, upon actuation, reverses the direction of the motor, and is actuatable separately through each of: (i) actuation of a moveable actuator of the switching circuit through movement of the drive member at least in the first direction; and (ii) manual actuation by a user of the surgical instrument.

[0045] Certain embodiments of the present invention will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting embodiments and that the scope of these embodiments is defined solely by the claims. The features illustrated or described in connection with one embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the appended claims.

[0046] In general, embodiments of the present invention are directed to a motor-driven surgical instrument that comprises a mechanically actuated slider for actuating an electric switch of the motor control circuit that controls the operation of the electric motor. For example, actuation of the switch may reverse the polarity of the voltage supplied to the motor, to thereby reverse the rotation of the motor. FIGS. 1 and 2 depict a motor-driven surgical cutting and fastening instrument 10 that may include the mechanically actuated slider according to various embodiments of the present invention. The illustrated embodiment is an endoscopic instrument and, in general, the embodiments of the instrument 10 described herein are endoscopic surgical cutting and fastening instruments. It should be noted, however, that the invention is not so limited and 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.

[0047] The surgical instrument 10 depicted in FIGS. 1 and 2 comprises a handle 6, a shaft 8, and an end effector 12 connected to the shaft 8. In various embodiments, the end effector 12 can be articulated about an articulation pivot 14. An articulation control 16 may be provided adjacent to the handle 6 to effect rotation 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 devices, such as graspers, cutters, staplers, clip appliers, access devices, drug/gene therapy devices, ultrasound, RF or laser devices, etc. More details regarding RF devices may be found in U.S. Pat. No. 5,403,312 and U.S. patent application Ser. No. 12/031,573, entitled “Surgical cutting and fastening instrument having RF electrodes, filed Feb. 14, 2008, both of which are incorporated by reference in their entirety.

[0048] 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 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 published U.S. Patent Application Publication No. 2007/0158385 A1, entitled “Surgical Instrument Having An Articulating End Effector,” by Geoffrey C. Hueil et al., which is incorporated herein by reference in its entirety.

[0049] 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, when the anvil 24 is in its clamped position, effective stapling and severing of tissue clamped in the end effector 12. The handle 6 includes a downwardly extending 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. In other embodiments, different types of clamping members besides the anvil 24 could be used. The handle 6 may also include an upper portion 28 that may sit on top of the user's hand when the user grips the pistol grip portion 26 with his/her hand.

[0050] 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.

[0051] In operational use, 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 on the handle 6, when depressed may release the locked closure trigger 18. The release button may be implemented in various forms such as, for example, as disclosed in published U.S. Patent Application Publication No. 2007/0175955, entitled “Surgical cutting and fastening instrument with closure trigger locking mechanism,” which is incorporated herein by reference in its entirety.

[0052] The end effector 12 may include a cutting instrument, such as knife, for cutting tissue clamped in the end effector 12 when the firing trigger 20 is retracted by a user. The end effector 12 may also comprise means for fastening the tissue severed by the cutting instrument, such as staples, RF electrodes, adhesives, etc. More details regarding possible configurations of the end effector 12 may be found in the following patents and published patent applications, which are incorporated herein by reference in their entirety: U.S. Pat. No. 5,709,680; U.S. Pat. No. 5,688,270; U.S. Pat. No. 7,000,818; U.S. Patent Publication No. 2005/0173490 A1; U.S. Patent Publication No. 2006/0025809 A1; U.S. Patent Publication No. 2007/0102453 A1; U.S. Patent Publication No. 2007/0102452 A1; U.S. Patent Publication No. 2009/0206134 A1; and U.S. Patent Publication No. 2009/0206124 A1.

[0053] The instrument 10 may also comprise a closure system for closing (or clamping) the end effector upon closure (or retraction) of the closure trigger 18. More details regarding embodiments of an exemplary closure system for closing (or clamping) the anvil 24 of the end effector 12 by retracting the closure trigger 18 are provided in the following U.S. Patent references, which are incorporated herein by reference in their entirety: U.S. Patent Publication No. 2004/0232196 A1; U.S. Patent Publication No. 2007/0175956 A1; U.S. Patent Publication No. 2007/0158385 A1; U.S. Patent Publication No. 2007/0175962 A1; U.S. Pat. No. 7,464,849; and the references cited in the paragraph above.

[0054] A longitudinally movable drive shaft located within the shaft 8 of the instrument 10 may drive/actuate the cutting instrument and the fastening means in the end effector 12. An electric motor, located in the pistol grip portion 26 of the handle 6 of the instrument 10, may be used to drive, indirectly, the drive shaft, as described further herein. In various embodiments, the motor may be a DC brushed driving motor having a maximum rotation of, approximately, 25,000 RPM. In other embodiments, the motor may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. A battery (or “power source” or “power pack”), such as a Li ion battery, may be provided in the pistol grip portion 26 of the handle 6 adjacent to the motor. The battery supplies electric power to the motor via a motor control circuit. According to various embodiments, a number of battery cells connected in series may be used as the power source to power the motor. In addition, the power source may be replaceable and/or rechargeable.

[0055] FIG. 3 is a schematic diagram of a control circuit 40 used to power the electric motor 42 with electrical power from a battery pack 44. In the illustrated embodiment, when a run motor (or fire) switch 46 is closed (it is shown in an open state in FIG. 3), and when a safety switch 48 is closed (it is shown open in FIG. 3), indicating that the device safety is set, and when a normally-closed lockout switch 50 is open, indicating that the instrument 10 is not in a lock-out condition, current flows through the safety switch 48, through a lockout indicator 52 (which may be a LED as shown in FIG. 3, that is located on the outside of the handle 6 such that it is visible to the operator of the instrument 10) to the motor 42. The run motor (or fire) switch 46 may be activated (or closed) when the operator of the instrument 10 retracts the firing trigger 20.

[0056] When the end of the cutting stroke is reached, that is, for example, when the cutting instrument in the end effector reaches the end of its cutting stroke, an end-of-stroke or direction switch 54 is switched to a closed position, reversing the polarity of the voltage applied to the motor 42 to thereby reverse the direction of rotation of the motor 42 (with the fire switch 46 also having been released or opened by the operator). In this state, current also flows through a reverse direction indicator 56, such as an LED that is located on the exterior of the handle 6 to provide a visual indication to the operator that the motor 42 direction has been reversed.

[0057] As shown in FIG. 3, the circuit may also comprise a manual return switch 58. The operator may manually flip this switch 58 if the cutting instrument in the end effector 12 has only been partially fired. Switching the manual return switch 58 may cause the motor 42 to reverse rotate, causing the cutting instrument to return to its original or home position. The switches of the motor control circuit 40 are not embodied as a part of a semiconductor-based integrated circuit (IC) according to various embodiments. For instance, in various embodiments, each of the switches may be separate microswitches or other suitable non-IC switches.

[0058] Additional embodiments for the motor control circuit 40 may be found in U.S. Pub. No. 2010/0076474, which is incorporated herein by reference in its entirety.

[0059] FIGS. 4-15 are views of a directional control assembly 70 for actuating a switch, such as the direction switch 54, of the motor control circuit 40 according to various embodiments of the present invention. The direction switch 54 may comprise, for example, a board-mountable microswitch that may be mounted on a lower surface of a circuit board 30 by pins 36. The circuit board 30 may be located in the upper portion 28 of the handle 6 (see FIGS. 1-2). Other circuit components for the motor control circuit 40 may be mounted to the circuit board 30 with conductive traces on the circuit board 30 connecting the components. For example, other switches of the motor control circuit 40 may also comprise board-mountable microswitches that are mounted to the circuit board 30, including either the upper and lower surfaces of the circuit board 30. The other electronic switches are shown in FIGS. 4-15 as element 34.

[0060] As shown more clearly in FIGS. 5-6 and 8-9, the direction switch 54 may comprise a moveable (e.g., depressible) switch actuator (e.g., plunger) 72. In various embodiments, when the depressible switch actuator 72 is depressed, the switch 54 is closed, thereby reversing the motor (with the fire switch 46 also having been released or opened by the operator). Conversely, when the depressible actuator 72 is undepressed, as shown in FIGS. 5-6 and 8-9, the direction switch 54 is open. Embodiments of the present invention are generally described herein where the directional control assembly 70 is used for actuating the direction switch of a motor control circuit, in a motor-driven surgical instrument, although it should be noted that the control assembly 70 could be used to actuate a switch with another purpose in another type of device or instrument, and that the present invention is not limited to embodiments where the control assembly is used to actuate a motor direction switch.

[0061] The depressible switch actuator 72 may be depressed, or actuated, by a slider 74, which may be made from a single piece of injection molded plastic, for example. In other embodiments, the slider 74 may comprise a combination of multiple, separate parts; some of parts may be made from materials other than plastic. FIGS. 16-19 provide view of the slider 74 according to various embodiments. FIG. 16 is a front perspective view; FIG. 17 is a back perspective view; FIG. 18 is a front view; and FIG. 19 is a distal side view. As shown in the illustrated embodiment, the slider 74 may comprise a cantilevered arm 76. As shown in FIGS. 4-15, the cantilevered arm 76 of the slider 74 engages the depressible switch actuator 72 of the switch 54 when the slider 74 is urged, or pushed, distally by a proximate-side channel shoulder 78 at a proximate side of a channel 80 defined by the front side of a rack 82. The back side of the rack 82 may comprise a series of teeth 84 that mesh with grooves of a pinion 86. The pinion 86 is geared to, and rotated by, an output gear of the motor 42. In that way, the rack 82 may be translated longitudinally, either distally or proximately, by rotation, either forward or reverse, of the pinion 86.

[0062] As seen in FIGS. 5-6, 9, 11, 13-15, the distal end of the rack 82 may define an opening 38 for receiving the proximate end of the drive shaft that drives the end effector 12. FIGS. 36-37 show the proximate end 148 of the drive shaft 150 positioned in the opening 38 of the rack 82. In such a configuration, longitudinal movement of the rack 82 (caused by rotation of the pinion 86, which is caused by rotation of the motor 42) causes the drive shaft 150 to move longitudinally, to thereby actuate (or deactuate) components of the end effector 12, such as the cutting instrument 154.

[0063] When the rack 82 is moved proximately, a distal-side channel shoulder 88 of the channel 80 may urge of push the slider 74 proximally, to thereby move the slider such that its cantilevered arm 76 is out of engagement with the actuator 72, so that the actuator 72 is not depressed, so that the direction switch 54 is in the open position.

[0064] As shown, for example, in FIGS. 16-19, the cantilevered arm 76 may comprise a first, upwardly sloping portion 90 extending from a base portion 92 of the slider 74, and a second, downwardly sloping portion 94 extending from the first portion 90. When the slider 74 is urged or pushed distally, the second portion 94 of the cantilevered arm 76 may engage and depress the depressible actuator 72 on the switch 54. In various embodiments, the slider 74 may be pushed distally such that the second portion 94 is pushed distally past the actuator 72 so that the actuator 72 is held in the depressed position by the first portion 90 of the cantilevered arm 76.

[0065] Also as shown in FIGS. 16-19, the slider 74 may comprise an integrated tab 96 that extends rigidly from the slider 74. The tab 96 may comprise a first portion 98 that extends from a back portion 122 of the slider 74 and a second portion 100 that extends from the first portion 98. The second portion 100 of the tab 96 may sit movably in the channel 80 of the rack 82, as shown in FIGS. 6, 10-11, and 14-15. The tab 96 may be pushed by either the proximate-side channel shoulder 78 or the distal-side channel shoulder 88 of the channel 80 when the rack 82 is moved longitudinally distally or proximately, respectively, to thereby move the slider 74 distally or proximately with the tab 96.

[0066] The slider 74 may also comprise a brace portion 128 extending between the base portion 92 and the back portion 122. The brace portion 128 may provide structural stability to the slider 74, reducing relative movement between the back portion 122 and the base portion 92. As shown in the figures, in various embodiments the brace portion 128 may be orthogonal to both the back portion 122 and the base portion 92.

[0067] FIGS. 4, 6, 9, 12, and 14 show the slider 74 at the distal end of the channel 80 of the rack 82. In this position, when the rack 82 is moving proximately, the distal-side channel shoulder 88 engages the tab 96 of the slider 74, pushing the tab 96, and thereby the slider 74, to its most proximate position, in which the depressible actuator 72 on the switch is unactuated (e.g., not depressed). FIGS. 20 and 21 show the slider 74 at the proximate end of the channel 80 of the rack 82. In this position, when the rack 82 is moving distally, the proximate-side channel shoulder 78 engages the 76 of the slider 74, pushing the tab 96, and thereby the slider 74, to its most distal position, in which the depressible actuator 72 on the switch 54 is actuated (e.g., depressed).

[0068] In such a manner, after the slider 74 is moved distally to actuate the switch 54, the slider 74 stays at its distal-most position and the switch 54 remains actuated by the slider 74 even when the rack 82 changes direction and moves proximately, until the distal-side shoulder 88 engages the tab 96 and moves the slider 74 proximately so that the slider 74 no longer actuates the switch 54. Similarly, after the slider 74 is moved proximately so that it no longer actuates the switch 54, the slider 74 remains disengaged from the switch 54 such that the switch 54 remains unactuated, even when the rack 82 changes direction and moves proximately, until the proximate-side shoulder 78 engages the tab 96 and moves the slider 74 back to is distal-most, switch-actuating position.

[0069] Also as shown in FIGS. 16-19, the slider 74 may comprise an upper arm 102 and a lower arm 104 that define a U-channel 106. The U-channel 106 may engage a stopper on a frame that supports the circuit board 30 when the slider 74 is pushed to its most distal position, as described further below. The stopper may tightly fit in the U-channel 106 such that the tightness of the fit keeps the slider 74 in the distal-most position even when the rack 82 is moving proximately. In various embodiments, the force from the distal channel shoulder 88 against the tab 96 is sufficient to disengage the U-channel 106 from the stopper on the frame, thereby allowing the slider 74 to be pushed by the distal channel shoulder 88 from its distal position (shown in FIGS. 4, 6, 9, 12, and 14) to its proximate position (shown in FIGS. 20-21). In that way, the slider 74 does not move with the rack 82, but only when the either of the channel shoulders 78, 88 of the rack 82 engage the tab 96 disposed in the rack channel 80, thereby pushing the slider 74.

[0070] As mentioned above, the U-channel 106 defined by the slider 74 engages a stopper on a frame inside in the handle 6 of the instrument 10. FIGS. 22 and 23 show a portion of the frame 110 with the stopper 112. As shown in these figures, the stopper 112 may extend from a side of the frame 110 facing the slider 74. The stopper 112 may be shaped to fit snugly into the U-channel 106 defined by the slider 106 when the slider 74 is in its distal-most position. FIG. 22 is a side view of the frame 110 and FIG. 23 is a perspective view of the frame 110. The frame 110 may be constructed from plastic, for example. The instrument 10 may comprise a second frame piece (not shown) that connects to the frame 110.

[0071] FIGS. 24-26 show both the frame 110 and the slider 74. Other components of the direction control assembly 70 are not shown in FIGS. 24-26 for convenience. FIG. 24 is a front perspective view of the frame 110 with the slider 74 in its proximate position such that the U-channel 106 is not engaged by the stopper 112 of the frame 110. FIG. 25 is a front side view with the slider 74 in the proximate position. When the slider 74 is in its proximate position, the cantilevered arm 76 of the slider 74 would not normally be depressing the depressible actuator 72 of the switch 54. Conversely, FIG. 26 is a front side view that shows the slider 74 in its distal-most position. When the slider 74 is in the distal-most position, the cantilevered arm 76 would normally be depressing the depressible actuator 72 of the switch 54.

[0072] As shown in FIGS. 16-19, the slider 74 may also comprise a frame tab 120 extending from the back portion 122 of the slider 74. The frame tab 120 may comprise a neck 124 and a head 126. The neck 124 may be disposed in a slot 130 in the side of the frame 110 facing the slider 74 (see FIGS. 22-27 for example). The slot 130 may confine the movement of the slider 74 relative the frame 110 as the rack 82 moves the slider 74 as described above.

[0073] FIGS. 27-31 show the frame 100 with the circuit board 30, the slider 74, the rack 82, and the pinion 86. The circuit board 30 may be connected to an upper surface of the frame 110, such as by screws or some other mounting technique. These figures also show portions of a gear assembly 120 that is geared to the pinion 86. The gear assembly 120 may couple the output drive shaft of the motor 42 to the pinion 86. FIG. 27 is a front side view; FIG. 28 is a back side view; FIG. 29 is a front side, distal perspective view; FIG. 30 is a back side, proximate perspective view; and FIG. 31 is a bottom side view.

[0074] FIG. 32 is a back side perspective view that shows the gear assembly 120 geared to the pinion 86 (without showing the frame 110). As shown in FIG. 32, the gear assembly 120 may comprise (i) an upper gear 122 that is geared to the pinion 86, and (ii) a lower gear assembly, covered by a lower gear assembly cover 124, that rotates the upper gear 122. The lower gear assembly may be coupled to the motor 42, as shown in FIGS. 33-35. These figures show the motor 42, with an output shaft 130, coupled to the gear assembly 120. As can be seen in these figures, the motor 42 may be positioned in the pistol grip portion 26 of the handle 6. These figures also show how the frame 110 fits into the upper portion 28 of the handle 6 according to various embodiments. The battery pack 44 (not shown in FIGS. 33-36) may be located in the pistol grip portion 26 of the handle 6 below the motor 42.

[0075] In addition, although in the embodiments describes above a pinion was used to longitudinally reciprocate the rack, other devices for longitudinally reciprocating the rack may be used in other embodiments. For example, a screw drive or other means may be used to longitudinally reciprocating the rack. Also, in other embodiments, the channel 80 of the rack 82 may comprise one or a number of wedges (or cams) that cause the slider 74 move generally perpendicular to the direction of movement of the rack 82 when the tab 96 of the slider 74 engages the wedge (or cam). In such embodiments, the perpendicular movement of the slider 74 (relative to the direction of movement of the rack 82) may actuate or deactuate the switch 54, depending on the location of the switch relative to the slider. In addition, in other embodiments, the rack 82 may comprise a cam and the slider 74 may comprise a cam follower. In such embodiments, longitudinal movement of the rack may induce eccentric motion in the slider 74, which may actuate or deactuate the switch 54, depending on the location of the switch relative to the slider.

[0076] In other embodiments, the portion (e.g., the tab 96) of the slider 74 that engages or interfaces with the channel 80 may be dynamic, thereby allowing the rack 82, with a fixed channel length, to be used in instruments where the cutting stroke of the end effector 12 is different for different procedures. For example, the slider may have multiple interface portions (e.g., tabs) that are selectively used depending on the situation. This may be desirous, for example, where the end effector 12 permits cartridges of different length, requiring different lengths of cut by the cutting instrument in the end effector 12. In other embodiments, the shaft/end effector combination may be replaceable to accommodate uses requiring different lengths of cut by the cutting instrument in the end effector 12. For short cutting strokes, the reverse direction switch 54 needs to be actuated sooner in the cutting stroke that for longer cutting strokes. FIG. 40 is a diagram of such a slider 74 according to various embodiments. FIG. 40 is a top view of a portion of the slider 74 showing the tab 96 extending outwardly into the channel 80 defined by the drive member 82. Adjacent to the 96 is a moveable second tab 400 that is capable of pivoting about one or more pivot points 402 on the body of the slider 74. The slider body may be connected to the moveable second tab 400 by pivoting arms 404. The pivoting arms 404 may permit the second tab 400 to rotate pivotably toward the channel 80 such that the second tab 400 extends into the channel 80. When the second tab 400 is pivoted so that it extends into the channel 80, the proximate-side channel shoulder 78 contacts the second tab 400 first, urging the slider body 74 into the switch-actuating position as described above, at a time and length of traveled distance less than it would take the shoulder 78 to contact the tab 96 if the second tab 400 was not extending into the channel 80. In that way, when the second tab 400 is extended into the channel, the switch 54 can be actuated sooner in the cutting stroke than when the second tab 400 does not extend into the channel. That way, the drive member 82 can be used in procedures where a shorting cutting stroke is used, requiring sooner activation of the reverse motor switch 54.

[0077] In various embodiments, the second tab 400 can be pivoted into the channel 80 by force from a pusher 408 that engages a portion 410 of the second tab 400. For example, relative to the view of FIG. 40, the portion 410 may extend downwardly, into the page, from the second tab 400 and the pusher 408 may be located below (into the page) the slider body 74. The pusher 408 may be urged proximately when a short cutting stroke is needed, thereby causing the pusher 408 to engage the extending portion 410 of the second tab 400, thereby causing the second tab 400 to extend into the channel 400. The pusher 408 may also comprise a wedge portion 412 that wedges between the slider body 74 and the second tab 400 so that second tab 400 remains rotated/extended even when the shoulder 78 engages the tab 400. Yet the pusher 408 may move with the slider 74 so that the slider 74 can be moved to its switch-actuating position when the proximate-side shoulder 78 of the channel 80 engages the second tab 400. In another embodiment, the pusher 408 may be moved toward the drive member 82 (rather than proximately) to thereby move the second tab 400 toward the channel 80.

[0078] The pusher 408 may be activated mechanically (such as by an operator-actuated lever or different shaft that cause the pusher 408 to be actuated) magnetically (such as by a solenoid) electrically (such as shape memory materials that change shape with heat caused by electrical current), or any other suitable means.

[0079] In addition, in various embodiments, the operation and movement of the slider 74 may be overridden by a user of the instrument to permit, for example, early return (proximate movement) of the rack 82. For example, the instrument 10 may comprise an externally-accessible manual override control (such as a lever or switch) that, when actuated by the user, causes the motor to stop or reverse direction, regardless of the status of the slider 74. For example, in one embodiment, actuation of the externally-accessible manual override control may disengage the pinion 86 from the rack 82 so that the rack 82 is not driven by the pinion 86. The motor control circuit in such an embodiment may include circuit components that reverse the motor even if the slider 74 is not in its switch-actuating position.

[0080] In addition, in other embodiments, rather than using a longitudinally-moving drive member (e.g., rack 82), the instrument may comprise a rotating drive member that drives the slider 74 relative to the switch 54. For example, FIG. 38 is a diagram of a spirally rotating (i.e., rotating about the roll axis) drive member 300. As shown in FIG. 38, the drive member 300 defines a helical channel 302 having a first shoulder 304 at the proximate-side of the channel 302 and a second shoulder 306 at the distal-side of the channel 302. When the drive member 300 forwards rotates about its roll axis, the proximate-side shoulder 304 may engage the slider 74 to urge it to its switch-actuating position. Similarly, when the drive member 300 reverse rotates about its roll axis, the distal-side shoulder 306 may engage the slider 74 to urge it to its non-switch-actuating position. The drive member 300 may be rotated by the motor 42 using an appropriate gearing structure.

[0081] In another embodiment, as shown in FIG. 39, the drive member 320 may be circular or elliptical, such as disk-shaped, and rotate about its yaw axis. In such an embodiment, the disk-shaped drive member 320 may define a peripheral channel 322 that extend partially around the periphery of the drive member 320. The channel 322 comprises a first shoulder 324 at a first side of the channel 322 and a second shoulder 326 at a second side of the channel 322. When the drive member 320 rotates CCW about its yaw axis, the first shoulder 324 may engage the slider 74 to urge it to its switch-actuating position. Similarly, when the drive member 320 rotates CW about its yaw axis, the second side shoulder 326 may engage the slider 74 to urge it to its non-switch-actuating position. The drive member 320 may be rotated by the motor 42 using an appropriate gearing structure. In FIG. 39, the channel 322 is a 90 degree arc; it other embodiments arcs of different size may be used for the channel.

[0082] The surgical instruments 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 surgical instrument, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the surgical instrument 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 surgical instrument 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 surgical instrument can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned surgical instrument, are all within the scope of the present application.

[0083] Preferably, the surgical instrument described herein will be processed before surgery. First, a new or used instrument is obtained and if necessary cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and 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 and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility.

[0084] Therefore, in various embodiments, the present invention is directed to a surgical instrument that comprises: (i) a handle; (ii) an end effector connected to the handle; (iii) an electric motor in the handle for powering the end effector; (iv) a motor control circuit connected to the motor for controlling the motor; (v) a drive member that is driven by the motor; and (vi) a slider. The motor control circuit comprises a plurality of switches, including a first switch with a moveable (e.g., depressible) actuator (e.g., plunger). The drive member, when driven by the motor, cause movement of a moveable component in the end effector, and comprises a first shoulder at a first position and a second shoulder at a second position. The slider comprises a first portion and a second portion. The first portion extends interfaces the drive member such that the slider is moveable in a direction of movement of the drive member when either the first shoulder or the second shoulder of the rack engages the first portion. The second portion of the slider actuates the moveable actuator of the first switch when the drive member moves the slider to a first position relative to the first switch. In various embodiments, the motor control circuit does not comprise an integrated circuit.

[0085] In various implementations, the drive member is rotated by the motor, such as about a roll axis or yaw axis of the drive member. In other embodiments, the drive member is drive longitudinally by the motor. For example, in such embodiments, the drive member may comprise a rack that is geared to a pinion that the rotated by the motor, such that rotation of the motor cause the rack to move longitudinally. The rack moves the slider to the first position relative to the first switch when the rack is moved longitudinally in a first direction by the pinion such that the first shoulder engages the tab of the slider, the slider remains in the first position relative to the first switch when the rack is moved longitudinally in a second direction by the pinion that is opposite the first direction until the second shoulder of the rack engages the tab of the slider, and the slider moves out of engagement with the moveable actuator when the second shoulder of the rack moves the slider from the first position relative to the first switch to a second position relative to the first switch.

[0086] The surgical instrument may further comprise a frame inside the handle that comprises a stopper. The slider may comprise an upper arm and a lower arm that collectively define a U-channel. The U-channel may engage the stopper when the slider is moved to the first position relative to the first switch.

[0087] In yet other general embodiments, the present invention is directed to a device that actuates a switch having a moveable actuator, where the device comprise: (i) a longitudinally-moveable rack; and (ii) a slider that engages the rack such that longitudinally movement of the rack causes the slider to move relative to the switch such that the slider actuates the moveable actuator of the switch when the rack moves the slider to a first position relative to the switch. In various implementations, longitudinal movement of the rack may cause longitudinal, perpendicular, or eccentric movement of the slider.

[0088] While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.