Surgical instrument drive systems

[0001] This application is a continuation application claiming priority under 35 U.S.C. § 120 to U.S. patent application Ser. No. 14/506,929, entitled END EFFECTORS FOR SURGICAL STAPLERS, which issued on Feb. 20, 2018 as U.S. Pat. No. 9,895,147, which is a continuation application claiming priority under 35 U.S.C. § 120 to U.S. patent application Ser. No. 12/731,347, entitled HYDRAULICALLY AND ELECTRICALLY ACTUATED ARTICULATION JOINTS FOR SURGICAL INSTRUMENTS, filed Mar. 25, 2010, which issued on Oct. 14, 2014 as U.S. Pat. No. 8,858,571, which is a divisional patent application claiming priority under 35 U.S.C. § 121 to U.S. patent application Ser. No. 11/270,866, entitled HYDRAULICALLY AND ELECTRICALLY ACTUATED ARTICULATION JOINTS FOR SURGICAL INSTRUMENTS, filed Nov. 9, 2005, now U.S. Patent Application Publication No. 2007/0106317, the entire disclosures of which are hereby incorporated by reference herein.

[0002] The present invention relates in general to surgical instruments that are suitable for endoscopically inserting an end effector (e.g., endocutter, grasper, cutter, staplers clip applier, access device, drug/gene therapy delivery device, an energy device using ultrasound, RF, laser, etc.) and, more particularly, to endocutters with articulating end effectors.

[0003] Endoscopic surgical instruments are often preferred over traditional open surgical devices since a smaller incision tends to reduce the post-operative recovery time and complications. Generally, these endoscopic surgical instruments include an “end effector”, a handle assembly and a long shaft that extends between the end effector and the handle assembly. The end effector is the portion of the instrument configured to engage the tissue in various ways to achieve a desired diagnostic or therapeutic effect (e.g., endocutter, grasper, cutter, staplers, clip applier, access device, drug/gene therapy delivery device, and energy device using ultrasound, RF, laser, etc.). The end effector and the shaft portion are sized to be inserted through a trocar placed into the patient. The elongated shaft portion enables the end effector to be inserted to a desired depth and also facilitates some rotation of the end effector to position it within the patient. With judicious placement of the trocar and use of graspers, for instance, through another trocar, often this amount of positioning is sufficient. Surgical stapling and severing instruments, such as those described in U.S. Pat. No. 5,465,895, are an example of an endoscopic surgical instrument that successfully positions an end effector by insertion and rotation.

[0004] Depending upon the nature of the operation, it may be desirable to further adjust the positioning of the end effector of an endoscopic surgical instrument. In particular, it is often desirable to orient the end effector at an angle relative to the longitudinal axis of the shaft of the instrument. The transverse or non-axial movement of the end effector relative to the instrument shaft is often conventionally referred to as “articulation”. This articulated positioning permits the clinician to more easily engage tissue in some instances, such as behind an organ. In addition, articulated positioning advantageously allows an endoscope to be positioned behind the end effector without being blocked by the instrument shaft.

[0005] Approaches to articulating a surgical stapling and severing instrument tend to be complicated by integrating control of the articulation along with the control of closing the end effector to clamp tissue and fire the end effector (i.e., stapling and severing) within the small diameter constraints of an endoscopic instrument. Generally, the three control motions are all transferred through the shaft as longitudinal translations. For instance, U.S. Pat. No. 5,673,840 discloses an accordion-like articulation mechanism (“flex-neck”) that is articulated by selectively drawing back one of two connecting rods through the implement shaft, each rod offset respectively on opposite sides of the shaft centerline. The connecting rods ratchet through a series of discrete positions.

[0006] Another example of longitudinal control of an articulation mechanism is U.S. Pat. No. 5,865,361 that includes an articulation link offset from a camming pivot such that pushing or pulling longitudinal translation of the articulation link effects articulation to a respective side. Similarly, U.S. Pat. No. 5,797,537 discloses a similar rod passing through the shaft to effect articulation. Still other examples of articulatable surgical stapling devices are disclosed in U.S. Pat. Nos. 6,250,532 and 6,644,532.

[0007] Due to the types end effector firing systems commonly employed, the actuator arrangements for articulating the end effector must often generate high amounts of torque to bend the firing structure. This problem is exacerbated by the lack of available space for accommodating actuating devices that are large enough to generate those required forces.

[0008] Consequently, a significant need exists for an articulating surgical instrument that incorporates an articulation mechanism that can generate the torque necessary to selectively articulate the end effector thereof in a desired manner.

[0009] In various embodiments, a surgical instrument for stapling the tissue of a patient is disclosed. The surgical instrument comprises a shaft and an end effector. The an end effector comprises a staple cartridge body including staple cavities defined therein, staples removably positioned in the staple cavities, an anvil configured to deform the staples, and a knife configured to cut tissue positioned intermediate the staple cartridge body and the anvil. The surgical instrument further comprises a staple drive system configured to eject the staples from the staple cavities and a knife drive system configured to move the knife relative to the staple cartridge body independently of the staple drive system.

[0010] In various embodiments, a surgical system for stapling the tissue of a patient is disclosed. The surgical system comprises a shaft and an end effector. The end effector comprises a staple cartridge body including staple cavities defined therein, staples removably positioned in the staple cavities, an anvil configured to deform the staples, and a knife configured to cut tissue positioned intermediate the staple cartridge body and the anvil. The surgical system further comprises a staple drive system configured to eject the staples from the staple cavities during a firing stroke and a knife drive system configured to move the knife relative to the stable cartridge body after the firing stroke.

[0032] Turning to the Figures, wherein like numerals denote like components throughout the several views, FIGS. 1 and 2 depict one embodiment of a surgical instrument 10 that is capable of practicing the unique benefits of the present invention. As can be seen in FIGS. 1 and 2, the instrument 10 includes a handle assembly 200 and a surgical implement portion 12. As used herein, the term “surgical implement” refers to a component or set of components configured to engage tissue to accomplish a surgical task. Examples of surgical implements include, but are not limited to: endocutters, graspers, clamps, cutters, staplers, clip appliers, probes or access devices, drug/gene therapy delivery devices, energy devices such as ultrasound, RF, or laser devices, etc.

[0033] In the non-limiting embodiment depicted in the Figures, the surgical instrument 10 includes a hydraulically actuated end effector 22 and handle arrangement 200 of the type disclosed in the U.S. patent application Ser. No. 11/270,217, entitled SURGICAL INSTRUMENT HAVING A HYDRAULICALLY ACTUATED END EFFECTOR, now U.S. Pat. No. 7,799,039, that was filed on Nov. 9, 2005 and which is commonly owned with the present application and which the disclosure thereof is hereby incorporated by reference in its entirety. As the present Detailed Description proceeds, however, the skilled artisan will readily appreciate that the unique and novel features of the various embodiments of the present invention may also be employed in connection with electrically actuated or pneumatically actuated end effectors. Thus, the various embodiments of the present invention may be advantageously employed in connection with a variety of surgical implements other than the exemplary embodiment depicted in the Figures without departing from the spirit and scope of the present invention. Accordingly, the scope of protection afforded to the various embodiments of the present invention should not be limited to use only with the specific type of surgical implements specifically described herein.

[0034] 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 material 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.

[0035] FIGS. 3-10 show views of one type of end effector 22 configured to perform clamping, severing and stapling of tissue according to various embodiments the present invention. In one embodiment, the end effector 22 has a body portion 24 that is provided with an elongate channel 26 for receiving a staple cartridge 60 therein. An anvil 28 is coupled to the body portion 24 and is capable of being selectively pivoted toward and away from cartridge 60 mounted in the elongate channel 26. FIGS. 3 and 10 illustrate the anvil 28 in an open position and FIGS. 4 and 5 illustrate the anvil 28 in a closed position. The anvil 28 may be closed hydraulically and returned to its open position by an energy storing device such as a spring 23. As can be seen in FIGS. 3-5, an actuation bladder 40 may be strategically mounted below a portion of the anvil 28 such that when the bladder 40 is inflated with a pressurized fluid or air, it biases the anvil 28 to its open position. A supply line 42 is coupled to the bladder 40 for supplying pressurized fluid from a reservoir 232 as will be described in further detail below. In alternative non-limiting embodiments, an additional hydraulic cylinder or cylinders may be advantageously employed to open and close the anvil. Still in other non-limiting embodiments, the anvil 28 may be opened and closed by slidable action of a distal tube segment 410 attached thereto.

[0036] One type of cartridge that may be used with such end effector is also depicted in FIGS. 3-10. The staple cartridge 60 has a cartridge body 62 that is divided by an elongated cutting slot 64 that extends from a proximal end 65 of the cartridge 60 toward a tapered outer tip 66. See FIG. 10. A plurality of staple-receiving channels 68 are formed within the staple cartridge body 64 and are arranged in spaced longitudinal rows 69 on each side of the elongated cutting slot 64. Positioned within the staple-receiving channels are staple drivers 70 that each support one or more staples 72 thereon. The staples 72 are advanced or “fired” by moving their respective drivers 70 in an upward direction toward the anvil 28.

[0037] FIG. 10 depicts a three dimensional view of the end effector 22 in an open position with a staple cartridge 60 installed in the elongate channel 26. On a lower surface 30 of the anvil 28, a plurality of staple-forming pockets 32 are arrayed to correspond to each staple receiving channel 68 in the cartridge body 62 when the cartridge 60 is installed in the end effector 22. More specifically, each forming pocket 32 in the anvil 28 may correspond to an individual staple 72 located within the staple cartridge 60. The staple cartridge 60 may be snap-fit into the elongate channel 26. For example, extension features 63 of the staple cartridge 60 engage recesses 27 (shown in FIG. 6) of the elongate channel 26.

[0038] In one embodiment, the staple drivers 70 are driven in an “upward” (toward the anvil 28) direction by a series of hydraulically actuated bladders 90, 92, 94, 96, 98, 100 situated within the elongated slot 26 of the end effector 22 and arranged such that when the bladders 90, 92, 94, 96, 98, 100 are inflated, they drive or “fire” the corresponding drivers 70 and their respective staples 72 toward the anvil 28. As the ends of the staple legs contact the corresponding staple forming pockets 32 in the anvil 28, they are bent over to close the staple 72. Various firing arrangements are disclosed in the above-mentioned patent application entitled SURGICAL INSTRUMENT HAVING A HYDRAULICALLY ACTUATED END EFFECTOR which has been herein incorporated by reference. Pressurized fluid or air is supplied to the bladders 90, 92, 94, 96, 98, 100 through a series of supply lines as shown in FIGS. 6 and 11.

[0039] Also in one embodiment, to facilitate cutting of tissue 8 clamped in the end effector 22, a hydraulically actuated cutting bar 110 is operatively mounted within the elongated channel 26 and arranged to be received within the elongated slot 64 in the cartridge body 62 when the cartridge 60 is mounted within the end effector 22. The cutting bar 110 extends longitudinally along the elongate slot 64 and is mechanically coupled to or otherwise supported on a support bar 111 which is attached to a hydraulic cutting bladder 102. By introducing a pressurized fluid or air into the cutting bladder 102, the cutting bar 110 is forced upward (represented by arrow A in FIG. 4) thereby causing the cutting bar 110 to sever the tissue 8 that is clamped between the anvil 28 and the cartridge 60. After the cutting bar 110 has severed the tissue 8, the pressurized fluid is permitted to exit the cutting bladder 102 to thereby permit the bladder 102 to deflate and permit the cutting bar 110 to move downward (arrow “B” in FIG. 3) to its retracted or unfired position. Pressurized fluid or air is supplied to the cutting bladder 102 by supply line 256.

[0040] As can be seen in FIGS. 1 and 2, the handle assembly 200 may house a hydraulic system generally designated as 210 for controlling the operation of the end effector 22. One embodiment of a hydraulic system 210 that may be employed to control the end effector 22 is depicted in schematic form in FIG. 11. In this non-limiting embodiment, a conventional hydraulic pump assembly 230 that includes a fluid reservoir 232 is employed to supply pressurized fluid to the various bladders. In one embodiment, the pump 230 is powered by a battery 234 supported within the handle assembly 200. However, the pump 230 could also be powered by other means, such as by alternating current or by a mechanical actuator. The pump 230 may be fluidically coupled to the reservoir 232 by supply line 236 that may have a conventional check valve 238 therein. See FIG. 11. As used herein, the term “fluidically coupled” means that the elements are coupled together with an appropriate supply, return, discharge, etc. line or other means to permit the passage of pressurized fluid medium, air, etc. therebetween. As used herein, the term “line” as used in “supply line”, “discharge line” or “return line” refers to an appropriate fluid passage formed from conduit, pipe, tubing, etc. for transporting pressurized fluid, air, etc. from one component to another.

[0041] In one embodiment, a discharge line 240 attached to the discharge port 231 of the pump 230 is piped to a manifold 242 that has designated supply lines for each bladder coupled thereto. For example, in the embodiment depicted in FIG. 11, a supply line 244 is coupled to bladder 90 and has a control valve 260 therein for controlling the flow of pressurized fluid through the line 244 to bladder 90. Supply line 246 is coupled to bladder 92 and has a control valve 262 therein. Supply line 248 is coupled to bladder 94 and has a control valve 264 therein. Supply line 250 is coupled to bladder 96 and has a control valve 266 therein. Supply line 252 is coupled to bladder 98 and has a control valve 268 therein. Supply line 254 is coupled to bladder 100 and has a control valve 270 therein. Supply line 256 is coupled to cutting bladder 102 and has control valve 272 therein. Supply line 42 is coupled to the anvil bladder 40 and the supply line 240 by line 241. A supply valve 274 is provided in line 241 for controlling the flow of pressurized fluid thereto and a return valve 276 is provided to permit the fluid to return from the bladder 40 into the manifold line 242 and through a return line 259 that is attached to the manifold 242 and the reservoir 232. As can be seen in FIG. 11, the return line 259 may have a return valve 278 therein. Valves 262, 264, 266, 268, 270, 272, 274, 276, 278 comprise a valve unit, generally designated as 280. In various non-limiting embodiments, the valves 262, 264, 266, 268, 270, 272, 274, 276, 278 may each comprise electrically actuated valves, such as, for example, piezo valves or Electro Active Polymer (EAP) valves which may be configured in response to an electrical signal. However, other suitable valve and valve arrangements could be employed.

[0042] The above-described valves may be operated by a control circuit 300 in response to input received from input buttons, such as buttons 308, 310, 312, 314, and/or 316 located on handle. The control circuit may also be powered by the battery 234 and comprise a suitable circuit capable of generating signals for configuring valve unit 280 in response to input from buttons 308, 310, 312, 314, 316 and/or from other portions of the handle such as a closure trigger 206 and/or a firing trigger 208 that are pivotally coupled thereto. In one non-limiting embodiment, the control circuit 300 may include a microprocessor and other related components including Random Access Memory (RAM), Read Only Memory (ROM), etc. In other non-limiting embodiments, the control circuit 300 may include various logical circuit elements.

[0043] As can be seen in FIGS. 1 and 2, in one non-limiting embodiment, the handle assembly 200 of the instrument 10 includes a pistol grip 204 that includes a closure trigger 206 that is pivotally attached thereto to commence closure of the anvil 28. In one embodiment, a closure trigger sensor 205 is employed to sense when the closure trigger 206 has been pivoted to the closed position. The closure trigger sensor 205 communicates with the control circuit to open the return valve 276 and return valve 278 and close supply valve 274 to permit the pressurized fluid to return from the anvil bladder 28 into the reservoir 232. The anvil 28 is then pivoted to the closed position by the return spring 23. The closure trigger 206 may be retained in the closed position by a release button latch arrangement 36 of the type disclosed in U.S. Pat. No. 6,905,057, entitled SURGICAL STAPLING INSTRUMENT INCORPORATING A FIRING MECHANISM HAVING A LINKED RACK TRANSMISSION, the disclosure of which is herein incorporated by reference in its entirety. Another non-limiting embodiment links the closure trigger 206 to the tube assembly 452 and causes it to move distally driving the distal tube 410 over the end effector assembly 24 closing the system.

[0044] When the end effector 22 is in the closed position, it may be inserted through the trocar 490. See FIG. 9. To reopen the end effector 22, the release button 36 is pressed to unlatch the closure trigger 206 to enable it to pivot away from the firing trigger 208 to an open position. When in the open position, the closure trigger sensor 205 signals the control circuit 300 to power pump 230 and open supply valve 274 and close return valve 276. Pressurized fluid is then pumped into the anvil bladder 40 to pivot the anvil 28 to the open position. When the clinician has oriented the end effector 22 such that the desired tissue is located between the open anvil 28 and the cartridge 60, the closure trigger 206 is pivoted to the closed position and latched. Valves 276 and 278 are opened and valve 241 is closed. Valves 276 and 278 are opened for a sufficient time to permit the fluid in the anvil bladder 40 to be returned therefrom through the lines 42, 242 and 259. Thereafter, those valves are closed. As indicated above, the use of the hydraulically powered bladder and return spring arrangement described herein is just one type of structure that may be employed to open and close the anvil 28. Other anvil control arrangements may be employed without departing from the spirit and scope of the present invention and, therefore, the protection afforded to the various embodiments of the present invention should not be limited solely to such bladder and return spring arrangement.

[0045] Input buttons 308, 310, 312, 314, 316 may provide input signals to the control circuit 300 in any suitable way. In one non-limiting embodiment, each input button 308, 310, 312, 314, 316 may correspond to a particular valve or valves for controlling the inflation of one or more bladders. While five actuation buttons are shown for this non-limiting embodiment, the reader will appreciate that other numbers of buttons may be employed. For example, if it is desirable to only actuate one stapling bladder at a time, a separate actuation button for each bladder may be provided. For example, button 308 may control valve 272 in the cutter supply line 256. By actuating that valve 272, pressurized fluid supplied by the pump 230 into the manifold 242 is permitted to flow through the supply line 256 into the cutting bladder 102. Likewise, if actuator button 310 is used to control valves 260, 262, activating the button 310 will cause the stapling bladders 90 and 92 to inflate and fire their corresponding staples 72. Multiple buttons may be selected to create firing patterns including more than one implement. In other non-limiting embodiments, each input button 308, 310, 312, 314, 316 may represent a pre-determined firing order and/or pattern. For example, selecting a button 308, 310, 312, 314, 316 may cause the control circuit 318 to configure the valve unit 304 such that hydraulic devices corresponding to particular surgical implements are fired when the firing trigger 28 is depressed. It will be appreciated that various embodiments may have more or fewer input buttons than are shown. In one embodiment, a firing trigger 208 is pivotally attached to the handle 200 outboard of the closure trigger 206 and one or more firing sensors (not shown) may be positioned to detect the position of the firing trigger. The firing sensors would then communicate with the control circuit 300 to control the various valves to permit pressurized fluid to flow to the various staple bladders to achieve a desired firing sequence.

[0046] In various non-limiting embodiments, the valve unit 280 may be configured to introduce a delay to the driving of one or more surgical implements included in the end effector 12. For example, it may be desirable to drive a cutting implement and then delay for a predetermined time before driving one or more zones of a stapling implement. The delay may be accomplished according to any suitable method. In one non-limiting embodiment, the control circuit 300 may configure the valve unit 280 to open a path for hydraulic fluid between the hydraulic pump 230 and a first surgical implement included in the end effector 12. When the firing trigger 28 is actuated, the pump 302 may generate pressurized hydraulic fluid, which drives the first surgical implement. The control circuit 300 may sense when the first surgical implement is driven (e.g., by sensing the position of the firing trigger 208) and begin a timer that counts off a predetermined delay time. At the expiration of the predetermined delay time, the control circuit 318 may configure the valve unit 280 to provide the pressurized hydraulic fluid to a second surgical implement. Hydraulic pressure generated at the actuation of the firing trigger 208 may be sufficient to drive the second surgical implement, or in various embodiments, the hydraulic pump 230 may be utilized to generate additional hydraulic pressure.

[0047] In one non-limiting embodiment of the present invention, the end effector 22 may be attached to the handle assembly 200 by an articulating joint assembly, generally designated as 400. As can be seen in FIGS. 1, 2, and 12-14, the articulating joint assembly 400 includes a distal tube segment 410 that has a distal end 412, a proximal end 414, and a distal axis H-H. The distal end 412 is mechanically (e.g., rigidly or slidably connected—depending upon the anvil closure arrangement employed) coupled to the end effector body 24. The distal tube 410 segment may be partially hollow with the proximal end being solid with a hose/wire receiving passage 416 therethrough.

[0048] The joint assembly 400 further includes a proximal tube segment 450, that has a proximal end 452, a distal end 454, and a proximal axis I-I. The proximal end 452 is attached to the handle assembly 200. In one embodiment, for example, the proximal end 452 may be attached to the handle assembly 200 by an internal channel retainer that is grounded to the handle assembly. However, other fastening arrangements could be employed. In one embodiment, the distal end 454 is solid and has a hollow hose/wire-receiving passage 456 therethrough. The remaining portion of the tube segment 450 may be hollow to permit passage of hoses and/or wires therethrough.

[0049] In one embodiment, the distal tube segment 410 is pivotally coupled to the proximal tube segment 450 by a ball joint assembly 460. In one embodiment, the ball joint assembly 460 comprises a hollow ball member 462 that is mounted to or formed on the proximal end 414 of the distal tube segment 410. The ball member 462 is substantially hollow or has a hollow passageway therein to permit the passage of hoses and/or wires therethrough. The ball member 462 is received in a socket 458 provided in the distal end of the proximal tube segment 450, such that the ball member 462 is free to pivot therein.

[0050] In one embodiment, an actuation assembly, generally designated as 500 is employed to articulate the distal tube segment 410 relative to the proximal tube segment 450. As can be seen in FIGS. 11-14, in one non-limiting embodiment, two articulation cylinders 510, 520 are employed. First articulation cylinder 510 may comprise a conventional hydraulic or pneumatic cylinder that has a first housing 512 that contains a first piston 514 therein. A first piston rod or first actuation rod 516 is attached to the first piston 514 and protrudes out of the first housing 512. Movement of the piston 514 within the first housing 512 in response to the admission of pressurized fluid or air on one side or the other side of the piston 514 causes the first actuation rod 516 to be extended out of the first cylinder housing 512 or into the first cylinder housing 512. A distal end 518 of the first housing 512 is pivotally (pinned) or otherwise rigidly attached to the proximal end 414 of the distal tube segment 410. The first actuation rod 516 is fabricated from a flexible material such as rubber or the like and the free end 519 thereof is rigidly affixed to the distal end 454 of the proximal tube segment 450. The free end 519 of the first actuation rod 516 may be attached to the distal end 454 by gluing, threads, etc. A first indentation 466 or a series of indentations are provided in the outer surface 464 of the ball member to provide the requisite clearance for the first actuation rod 516 and also the end of the first cylinder housing 512.

[0051] Also in this non-limiting embodiment, the second articulation cylinder 520 may comprise a conventional hydraulic or pneumatic cylinder that has a second housing 522 that contains a second piston 524 therein. A second piston rod or second actuation rod 526 is attached to the second piston 526 and protrudes out of the second housing 522. Movement of the second piston 524 within the second cylinder housing 522 in response to the admission of pressurized fluid or air on one side or the other side of the second piston 524 causes the actuation rod 526 to be extended out of the second cylinder housing 522 or into the second cylinder housing 522. The second cylinder housing 522 is pivotally (pinned) or otherwise rigidly attached to the proximal end 414 of the distal tube segment 410. The second actuation rod 526 is fabricated from a flexible material such as rubber or the like and the free end 529 thereof is rigidly affixed to the distal end 454 of the proximal tube segment 450. The free end 529 of the second actuation rod 526 may be attached to the distal end 454 by gluing, threads, etc. A second indentation 468 or a series of indentations are provided in the outer surface 464 of the ball member 462 to provide the requisite clearance for the second actuation rod 526 and also the end of the second cylinder housing 522.

[0052] The first and second articulation cylinders 510, 520 may be powered by the hydraulic system 210 or they may be powered by a separate hydraulic system. FIG. 11 depicts one method of controlling the first and second articulation cylinders 510, 520. As can be seen in that Figure, a supply line 570 is connected to the supply line 240 from the pump 230. A first portion 572 of the supply line 570 is attached to a first supply port in the first cylinder housing 512 for supplying pressurized fluid or air into the first cylinder housing 512 on one side of the first piston 514 and a second portion 574 of the supply line 570 is attached to a second supply port in the first housing 512 for supplying pressurized fluid or air into the first housing 512 on the other side of the first piston 514. A first supply valve 576 is mounted in the first portion 572 of the supply line 570 and a second supply valve 578 is mounted in the second portion 574 of the first supply line 570. An exhaust or return line 580 is provided to return the pressurized fluid from the first housing 512 to the fluid reservoir 232. The return line 580 has a first portion 582 and a second portion 584 attached to ports in the first housing 512. A first return valve 586 is mounted in the first portion 582 of the return line 580 and a second return valve 588 is mounted in the second portion 584 of the return line.

[0053] The supply line 570 further has a third portion 590 that is coupled to a third supply port in the second housing 522 on one side of the second piston 524 and the supply line 570 has a fourth portion 592 coupled to a fourth supply port in the second housing 522 on the other side of the second piston 524. A valve 596 is mounted in the third portion 590 and another valve 598 is mounted in fourth portion 592 of the supply line 570. Another return line 600 is provided to permit the pressurized fluid, air, etc. to return to the reservoir 232 from the housing 522 during actuation of the cylinder 520. The return line 600 has a third portion 602 attached to a third return port in the second housing 522 on one side of the second piston 524 and a fourth portion 604 of the return line 600 is coupled to a fourth return port in the second housing 522 on the other side of the second piston 524. A return valve 606 is provided in the third portion 602 of the return line 600 and another return valve 608 is provided in the portion 604 of the return line 600.

[0054] The valves may be controlled by the control circuit 300 or a second control circuit 300′ of the type described above that may include a microprocessor and other related components including Random Access Memory (RAM), Read Only Memory (ROM), etc. In other non-limiting embodiments, the control circuit 300′ may include various logical circuit elements. A conventional multiposition switch 610 or a series of switches, push buttons etc. may be connected to the second control circuit 300′ for controlling the valves 576, 578, 586, 588, 594, 596, 606, 608 to control the cylinders 510, 520 in the manners necessary to achieve the desired degree and direction of articulation.

[0055] When pivotally attached together as described above, the proximal and distal tube segments 410, 450 form a tube assembly 470 that has a passageway 472 or passageways for supporting the supply lines (collectively designated as 480) between the end effector 22 and the handle 200. It will be appreciated that the tube assembly 470 has a circumference “C” and shape such that when the distal tube 410 segment is coaxially aligned with the proximal tube segment 450, the tube assembly 470 may be inserted through the passageway 492 in a trocar 490. See FIG. 9. In one embodiment, the first and second tube segments 410, 450 have a round cross-sectional shape and are sized to be axially inserted through a round trocar passageway 492. The outer diameters of each the distal tube segments 410, 450 are less than the inner diameter of the trocar passageway 492 to facilitate axial insertion of the tube assembly 470 through the trocar passage 492 and, if desired or necessary, rotation of the tube assembly 470 within the trocar passageway 492. For example, if the trocar passageway 492 has an inner diameter of approximately 12.8 mm (0.503 inches), the maximum outer diameter of tube assembly 470 (and of each of the tube segments 410, 450) may be approximately 12.7 mm (0.500 inches). It is conceivable that, for applications wherein the ability to rotate the tube assembly 470 within the trocar passageway 492 is not necessary or desirable, trocars with passageways having non-circular cross-sections could be employed. In those cases, the tube assembly would have a cross-sectional shape that would facilitate axial insertion of the tube assembly through the trocar passageway and may closely resemble the cross-sectional shape of the trocar passageway. Thus, the various embodiments of the subject invention should not be limited to devices having a tube assembly with a round cross-sectional shape.

[0056] FIG. 1 illustrates the joint assembly in a non-articulated position that would enable the tube assembly 470 to be inserted into the trocar. After the surgical implement 12 has been inserted through the trocar 490 and it becomes desirable to articulate the implement 12, the clinician activates the control circuit 300′ through switch 610. Depending upon the degree and direction of articulation desired, the first piston 516 and the second piston 526 may either both be extended, one extended and one retracted or both retracted to cause the ball member 462 to pivot in the socket to achieve the desired amount of articulation. The pistons 516 and 526 are extended by the clinician by activating multiposition switch or buttons located on the handle assembly to cause the control circuit 300′ to open and close the various control valves 576, 578, 586, 588, 594, 596, 606, 608. The reader will appreciate that the first and second actuation rods 516, 526 may, depending upon the forces, tend to bend rather than pivot during actuation and it is the deflection and buckling of these rods 516, 526 that further causes the distal tube segment 410 to articulate relative to the proximal tube segment 450. Moreover, if the articulation cylinders 510,520 are not aligned 180 degrees about the longitudinal axis of the device, they can be used to articulate the end effector in multiple planes as well as merely pivoting it about a point perpendicular to the longitudinal axis. Such pivotal flexibility is made possible through use of the ball joint arrangement of this embodiment. Such arrangement represents a significant improvement over other arrangements that can only articulate about a single axis.

[0057] The hydraulic control system described above for actuating the articulation cylinders 510, 520 is but one example of a control system that may be used. The reader will appreciate that a variety of different control arrangements may be employed to activate the articulation cylinders without departing from the spirit and scope of the present invention. For example, the articulation cylinders 510, 520 as described above require the admission of pressurized fluid/air to move their respective pistons in both directions. Other cylinders that employ springs or other mechanisms for returning the pistons to a starting position may be employed along with appropriate valve and hydraulic fluid supply arrangement that are within the capabilities of the skilled artisan may be employed. It will be further appreciated that, while two articulation cylinders have been described above, other embodiments of the present invention may employ only one articulation cylinder or more than two articulation cylinders. Also, while the ball member 462 has been described as being non-movably mounted to the distal tube segment 410 with the socket 458 provided in the proximal tube segment 450, those of ordinary skill in the art will understand that the ball member 462 may be non-movably attached to the proximal tube segment 450 and the socket 458 provided in the distal tube segment 410 in other non-limiting embodiments without departing form the sprit and scope of the present invention.

[0058] FIG. 15 illustrates another articulation joint assembly 1400 embodiment of the present invention. As can be seen in that Figure, distal tube segment 1410 has a proximal end 1414 and a distal axis H′-H′. Although not shown in FIG. 15, the distal tube segment 1410 has a distal end 1412 that is mechanically coupled to the end effector body 24. Depending upon the anvil closure arrangement employed, the distal end 1412 may be non-movably attached to the end effector body or by a cable, flexible member or pivotable member. The distal tube 1410 segment may be partially hollow with the proximal 1414 end being solid with a hose/wire receiving passage 1416 therethrough.

[0059] The joint assembly 1400 further includes a proximal tube segment 1450, that has a distal end 1454, and a proximal axis I′-I′. Although not shown in FIG. 15, the proximal tube segment 1450 has a proximal end that is mechanically attached to the handle assembly 200.

[0060] In one embodiment, the distal tube segment 1410 is pivotally coupled to the proximal tube segment 1450 by a ball joint assembly 1460. In one embodiment, the ball joint assembly comprises a hollow ball member 1462 that is mounted to or is formed on the distal end 1454 of the proximal tube segment 1450. The ball member 1462 has a hollow passageway 1464 that has a flared or otherwise enlarged end portion 1465 to enable it to communicate with the passageway 1416 such that, regardless of the position of the ball member 1462, the hoses 480 and/or wires extending therethrough will not be pinched or otherwise damaged. The ball member 1462 is received in a socket 1458 provided in the proximal end 1414 of the distal tube segment 1410, such that the ball member 1462 is free to pivot or rotate therein.

[0061] In one embodiment, an actuation assembly, generally designated as 1500 is employed to articulate the distal tube segment 1410 relative to the proximal tube segment 1450. As can be seen in FIG. 15, in one non-limiting embodiment, two articulation cylinders 1510, 1520 are employed. First articulation cylinder 1510 may comprise a conventional hydraulic or pneumatic cylinder that has a first housing 1512 that contains a first piston 1514 therein. A first piston rod or first actuation rod 1516 is attached to the first piston 1514 and protrudes out of the first housing 1512. Movement of the piston 1514 within the first housing 1512 in response to the admission of pressurized fluid or air on one side or the other side of the piston 1514 causes the first actuation rod 1516 to be extended out of the first cylinder housing 1512 or into the first cylinder housing 1512. A distal end 1518 of the first housing 1512 is pivotally (pinned) to a portion 1415 of the proximal end 1414 of the distal tube segment 1410. The outer surface of the proximal end 1414 in the area of the first cylinder housing 1512 may be contoured to facilitate pivotal movement of the cylinder housing 1512. The first actuation rod 1516 may be fabricated from a flexible material such as rubber or the like or it may be fabricated from rigid material. The free end 1519 of the actuation rod 516 is pivotally pinned to or otherwise attached to the distal end 1454 of the proximal tube segment 1450.

[0062] Also in this non-limiting embodiment, the second articulation cylinder 1520 may comprise a conventional hydraulic or pneumatic cylinder that has a second housing 1522 that contains a second piston 1524 therein. A second piston rod or second actuation rod 1526 is attached to the second piston 1524 and protrudes out of the second housing 1522. Movement of the second piston 1524 within the second cylinder housing 1522 in response to the admission of pressurized fluid or air on one side or the other side of the second piston 1524 causes the actuation rod 1526 to be extended out of the second cylinder housing 1522 or into the second cylinder housing 1522. The distal end 1523 of the second cylinder housing 1522 is pivotally (pinned) to a portion 1417 of the proximal end 1414 of the distal tube segment 1410. The outer surface of the proximal end 1414 in the area of the second cylinder housing 1522 may be contoured to facilitate pivotal movement of the cylinder housing 1522. The second actuation rod 1526 may be fabricated from a flexible material such as rubber or the like or it may be fabricated from rigid material. The free end 1529 of the actuation rod 1526 is pivotally pinned to or otherwise attached to the distal end 1454 of the proximal tube segment 1450.

[0063] The first and second articulation cylinders 1510, 1520 may be powered by the hydraulic system 210 in the same manner as was discussed in detail above with respect to cylinders 510, 520 or they may be powered by a separate hydraulic system. FIG. 11 depicts one method of controlling the first and second articulation cylinders 1510, 1520. The distal tube segment 1410 (and the end effector 22 attached thereto) may be articulated relative to the proximal tube 1450 in the direction shown in FIG. 15 by extending the actuation rod 1526 and retracting the actuation rod 1516. Likewise, the distal tube segment 1410 may be pivoted to a direction opposite to the direction shown in FIG. 15 by extending the actuation rod 1516 and retracting the actuation rod 1526. The control circuit 300′ may actuate the cylinders 1510, 1520 in these manners in response to the position of the multiposition control switch 610 on the handle assembly 200. The reader will also appreciate that, while two articulation cylinders have been described above, other embodiments of the present invention may employ only one articulation cylinder if only one degree articulation is needed or desired. Also, while the ball member 1462 has been described as being non-movably mounted to the proximal tube 1450 with the socket 1458 provided in the distal tube segment 1410, those of ordinary skill in the art will understand that the ball member 1462 may be non-movably attached to the distal tube segment 1410 and the socket 1458 provided in the proximal tube segment 1450 in other non-limiting embodiments without departing from the spirit and scope of the present invention.

[0064] In an alternative embodiment depicted in FIG. 15A, the joint assembly 1460′ comprises a round disc-like member 1462′ instead of a ball shaped member. The disc 1462′ has a hollow passageway 1464′ that has a flared or otherwise enlarged end portion 1465′ to enable it to communicate with the passageway 1416 such that, regardless of the position of the disc-like member 1462′, the hoses 480 and/or wires extending therethrough will not be pinched or otherwise damaged. The disc-like member 1462′ is received in a socket 1458′ provided in the proximal end 1414 of the distal tube segment 1410, such that the disc-like member 1462′ is free to pivot therein. If desired, the outer edge of the disc-like member 1462′ could be provided with a tongue (not shown) that is received in a groove (not shown) in the socket wall to further stabilize the disc-like member 1462′. This embodiment otherwise employs actuators 1510 and 1520 as described above. Again, however, the reader will appreciate that, while two articulation cylinders have been described above, other embodiments of the present invention may employ only one articulation cylinder if only one degree articulation is needed or desired. Also, while the disc-like member 1462′ has been described as being non-movably mounted to the proximal tube segment 1450 with the socket 1458′ provided in the distal tube segment 1410, those of ordinary skill in the art will understand that the disc-like member 1462′ may be non-movably attached to the distal tube segment 1410 and the socket 1458′ provided in the proximal tube segment 1450 in other non-limiting embodiments without departing from the spirit and scope of the present invention.

[0065] Another alternative embodiment is depicted in FIG. 16. As can be seen in this embodiment, the end 1519 of the first actuation rod 1516 of cylinder 1510 is attached to portion of the outer surface of the ball member 1462 and the end 1529 of the second actuation rod 1516 is also attached to a portion of the ball member 1462. This embodiment is otherwise identical in composition and operation as the embodiment depicted in FIG. 15 and described above. Again, however, the reader will appreciate that, while two articulation cylinders have been described above, other embodiments of the present invention may employ only one articulation cylinder if only one degree articulation is needed or desired. Also, while the ball member 1462 has been described as being non-movably mounted to the proximal tube segment 1450 with the socket 1458 provided in the distal tube segment 1410, those of ordinary skill in the art will understand that the ball member 1462 may be non-movably attached to the distal tube segment 1410 and the socket 1458 provided in the proximal tube segment 1450 in other non-limiting embodiments without departing from the sprit and scope of the present invention.

[0066] Another alternative embodiment is depicted in FIG. 16A. As can be seen in this embodiment, the end 1519 of the first actuation rod 1516 of cylinder 1510 is attached to portion of the outer surface of the disc-like member 1462′ and the end 1529 of the second actuation rod 1516 is also attached to a portion of the disc-like member 1462′. This embodiment is otherwise identical in composition and operation as the embodiment depicted in FIG. 16A and described above. Again, however, the reader will appreciate that, while two articulation cylinders have been described above, other embodiments of the present invention may employ only one articulation cylinder if only one degree articulation is needed or desired. Also, while the disc-like member 1462′ has been described as being non-movably mounted to the proximal tube segment 1450 with the socket 1458′ provided in the distal tube segment 1410, those of ordinary skill in the art will understand that the disc-like member 1462′ may be non-movably attached to the distal tube segment 1410 and the socket 1458′ provided in the proximal tube segment 1450 in other non-limiting embodiments without departing from the spirit and scope of the present invention.

[0067] FIG. 17 illustrates yet another articulation joint assembly 2400 embodiment of the present invention. As can be seen in that Figure, distal tube segment 2410 has a proximal end 2414 and a distal axis H″-H″. Although not shown in FIG. 17, the distal tube segment 2410 has a distal end that is mechanically coupled to the end effector body 24. Depending upon the anvil closure arrangement employed, the distal end may be non-movably attached to the end effector body or by a cable, flexible member or pivotable member. The distal tube 2410 segment may be partially hollow with the proximal end 2414 being solid with a hose/wire receiving passage 2416 therethrough. The passage 2416 may have a conical shaped portion 2417.

[0068] The joint assembly 2400 further includes a proximal tube segment 2450, that has a distal end 2454, and a proximal axis I″-I″. Although not shown in FIG. 18, the proximal tube segment 2450 has a proximal end 2454 that is attached to the handle assembly 200.

[0069] In one embodiment, the distal tube segment 2410 is pivotally coupled to the proximal tube segment 2450 by a ball joint assembly 2460. In one embodiment, the ball joint assembly 2460 comprises a ball member 2462 that is mounted to or is formed on the distal end 2454 of the proximal tube segment 2450. The ball member 2462 has a hollow passageway 2464 that has a flared or otherwise enlarged end portion 2465 to enable it to communicate with the passageway portions 2416, 2417 such that, regardless of the position of the ball member 2462, the hoses 480 and/or wires extending therethrough will not be pinched or otherwise damaged. The ball member 2462 is received in a socket 2458 provided in the proximal end 2414 of the distal tube segment 2410, such that the ball member 2462 is free to rotate therein.

[0070] In one embodiment, an actuation assembly, generally designated as 2500 is employed to articulate the distal tube segment 2410 relative to the proximal tube segment 2450. As can be seen in FIG. 17, in one non-limiting embodiment, two flexible worm gear cables 2510, 2520 are employed. The first flexible worm gear cable 2510 is adapted to drivingly engage worm gear teeth, threads, etc. (not shown) within a first gear passage 2465 formed in the ball member 2462. The first flexible worm gear cable 2510 is coupled to a first motor 2512 that is mounted within the distal tube segment 2410. Similarly, in this non-limiting embodiment, a second flexible worm gear cable 2520 is adapted to drivingly engage gear teeth, threads, etc. within a second gear passage 2467 formed in the ball member 2462 that has worm gear teeth, threads, etc. 2469 formed therein. The second flexible worm gear cable 2520 is coupled to a second motor 2522 mounted in the distal tube segment 2410. While described herein as “flexible worm gear cables”, it will be understood that this term is meant to encompass all types of flexible driven cable or driver arrangements that do not necessarily employ worm gear-type teeth thereon.

[0071] The first and second motors 2512, 2522 may be electrically powered (by battery 234 or another battery) or be powered by alternating current or be powered by hydraulic fluid or air. In one embodiment, the motors 2512, 2522 are electric powered and are operated by one or more switches or buttons (not shown) on handle assembly 200. By controlling the amount of rotation and the direction of rotation of the first and second worm gear cables 2510, 2520, the ball member 2462 is cause to rotate within the socket 2458 and thereby articulate the distal tube segment 2410 (and the end effector 22 attached thereto) relative to the proximal tube segment 2450. The reader will appreciate that such arrangement facilitates left articulation as shown in FIG. 17 and right articulation (not shown). Again, however, the reader will appreciate that, while two flexible worm gear cable/motor arrangements have been described above, other embodiments of the present invention may employ only one flexible worm gear cable arrangement if only one degree articulation is needed or desired. Also, while the ball member 2462 has been described as being non-movably mounted to the proximal tube segment 2450 with the socket 2458 provided in the distal tube segment 2410, those of ordinary skill in the art will understand that the ball member 2462 may be non-movably attached to the distal tube segment 2410 and the socket 2458 provided in the proximal tube segment 2450 in other non-limiting embodiments without departing from the spirit and scope of the present invention.

[0072] In an alternative embodiment depicted in FIG. 17A, the joint assembly 2460′ comprises a round disc-like member 2462′ instead of a ball shaped member. The disc-like member 2462′ has a hollow passageway 2464′ that has a flared or otherwise enlarged end portion 2465′ to enable it to communicate with the passageway 2416 such that, regardless of the position of the disc-like member 2462′, the hoses 480 and/or wires extending therethrough will not be pinched or otherwise damaged. The disc-like member 2462′ is received in a socket 2458′ provided in the proximal end 2414 of the distal tube segment 2410, such that the disc-like member 2462′ is free to rotate therein. If desired, the outer edge of the disc-like member 2462′ could be provided with a tongue (not shown) that is received in a groove (not shown) in the socket wall to further stabilize the disc-like member 1462′. This embodiment otherwise employs the motor driven flexible worm gear cables 2510 and 2520 as described above. Again, however, the reader will appreciate that, while two flexible worm gear cable/motor arrangements have been described above, other embodiments of the present invention may employ only one flexible worm gear cable arrangement if only one degree articulation is needed or desired. Also, while the disc-like member 2462′ has been described as being non-movably mounted to the proximal tube segment 2450 with the socket 2458′ provided in the distal tube segment 2410, those of ordinary skill in the art will understand that the disc-like member 2462′ may be non-movably attached to the distal tube segment 2410 and the socket 2458′ provided in the proximal tube segment 2450 in other non-limiting embodiments without departing from the spirit and scope of the present invention.

[0073] The various non-limiting embodiments of the present invention provide a host of advantages over prior art articulated surgical instruments. In particular, the various embodiments of the subject invention enable the portions of the tube member that attach a surgical implement to a handle to be inserted through a trocar or similar device and then be selectively articulated within the patient. While the various embodiments have been described herein in connection with use with a hydraulically operated endocutter, those of ordinary skill in the art would appreciate that the various embodiments of the subject invention could be employed with electrically powered endocutters and with a host of other types of surgical implements, regardless of whether they are electrically or hydraulically powered.

[0074] While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art. Accordingly, the present invention has been discussed in terms of endoscopic procedures and apparatus. However, use herein of terms such as “endoscopic” should not be construed to limit the present invention to a surgical stapling and severing instrument for use only in conjunction with an endoscopic tube (i.e., trocar). On the contrary, it is believed that the present invention may find use in any procedure where access is limited to a small incision, including but not limited to laparoscopic procedures, as well as open procedures. Moreover, the various embodiment of the present invention should not be limited solely to use in connection with surgical instruments that have hydraulically powered or air powered surgical implements. The various embodiments of the present invention may also be effectively used with surgical instruments and the like that employ electrically driven surgical implements.