Surgical instrument having an articulating end effector

[0001] The present invention relates in general to surgical instruments, and more particularly to minimally invasive surgical instruments having an articulating end effector.

[0002] Endoscopic and other minimally invasive surgical instruments typically include an end effector positioned at the distal end of an elongate shaft and a handle at the proximal end of the elongate shaft allowing a clinician to manipulate the end effector. In use, the end effector is provided to a surgical site through a cannula of a trocar. At the surgical site, the end effector engages tissue in any number of ways to achieve a diagnostic or therapeutic effect. Endoscopic surgical instruments are often preferred over traditional open surgical instruments because they require smaller incisions that generally heal with less post-operative recovery time than traditional open surgery incisions. Because of this and other benefits of endoscopic surgery, significant development has gone into a range of endoscopic surgical instruments having end effectors that engage tissue to accomplish a number of surgical tasks. For example, end effectors have been developed to act as endocutters, graspers, cutters, staplers, clip appliers, access devices, drug/gene therapy delivery devices, ultrasound, RF, or laser energy devices, and other surgical instruments.

[0003] FIGS. 1 & 2 show an exemplary prior art surgical and stapling instrument 10 including an end effector 12 configured as an endocutter for clamping, severing and stapling tissue, for example, as disclosed in U.S. Application Publication No. 2004/0232196 A1, the disclosure of which is herein incorporated by reference in its entirety. The surgical stapling and severing instrument 10 includes a handle portion 20 connected to an implement portion 22, the latter further comprising a shaft 23 distally terminating in the end effector 12. The handle portion 20 includes a pistol grip 24 toward which a closure trigger 26 is pivotally drawn by the clinician to cause clamping, or closing, of the anvil 18 toward the elongate channel 16 of the end effector 12. A firing trigger 28 is farther outboard of the closure trigger 26 and is pivotally drawn by the clinician to cause the stapling and severing of clamped tissue in the end effector 12.

[0004] Closure trigger 26 is actuated first. Once the clinician is satisfied with the positioning of the end effector 12, the clinician may draw back the closure trigger 26 to its fully closed, locked position proximate to the pistol grip 24. Then, the firing trigger 28 is actuated. The firing trigger 28 springedly returns when the clinician removes pressure. A release button 30 when depressed on the proximal end of the handle portion 20 releases any locked closure trigger 26.

[0005] A closure sleeve 32 encloses a frame 34, which in turn encloses a firing drive member 36 that is positioned by the firing trigger 28. The frame 34 connects the handle portion 20 to the end effector 12. With the closure sleeve 32 withdrawn proximally by the closure trigger 26 as depicted, the anvil 18 opens, pivoting away from the elongate channel 16 and translating proximally with the closure sleeve 32. The elongate channel 16 receives a staple cartridge 37.

[0006] With particular reference to FIG. 2, the firing bar 14 includes three vertically spaced pins that control the spacing of the end effector 12 during firing. In particular, an upper pin 38 is staged to enter an anvil pocket 40 near the pivot between the anvil 18 and elongate channel 16. When fired with the anvil 18 closed, the upper pin 38 advances distally within a longitudinal anvil slot 42 extending distally through anvil 18. Any minor upward deflection in the anvil 18 is overcome by a downward force imparted by the upper pin 38.

[0007] Firing bar 14 also includes a lower most pin, or firing bar cap, 44 that upwardly engages a channel slot 45 in the elongate channel 16, thereby cooperating with the upper pin 38 to draw the anvil 18 and the elongate channel 16 slightly closer together in the event of excess tissue clamped therebetween.

[0008] The firing bar 14 advantageously includes a middle pin 46 that passes through a firing drive slot 47 formed in a lower surface of the cartridge 37 and an upward surface of the elongate channel 16, thereby driving the staples therein as described below. The middle pin 46, by sliding against the lower surface of the cartridge 37, advantageously resists any tendency for the end effector 12 to be pinched shut at its distal end.

[0009] A distally presented cutting edge 48 between the upper and middle pins 38, 46 on the firing bar 14 traverses through the cartridge 37 to sever clamped tissue. The affirmative positioning of the firing bar 14 with regard to the elongate channel 16 and anvil 18 assure that an effective cut is performed.

[0010] The affirmative vertical spacing provided by the E-Beam firing bar 14 is suitable for the limited size available for endoscopic devices. Moreover, the E-Beam firing bar 14 enables fabrication of an anvil 18 with a camber imparting a vertical deflection at its distal end. This cambered anvil 18 advantageously assists in achieving the desired gap in the end effector 12 even with an anvil 18 of reduced thickness, which is thus more suited to the size limitations of an endoscopic device.

[0011] The E-Beam firing bar 14 further enables increased applications, especially in combination with a range of configurations of staple cartridges. For instance, a clinician may select a gray staple cartridge yielding a 0.02 mm tissue gap, a white staple cartridge yielding a 0.04 mm tissue gap, a blue cartridge yielding a 0.06 mm tissue gap, or a green cartridge yielding a 0.10 mm tissue gap. The vertical height of each respective staple cartridge in combination with the length of staples and an integral wedge sled 50 predetermines this desired tissue thickness with the anvil 18 appropriately vertically spaced by the E-Beam firing bar 14.

[0012] With surgical instrument 10 as well as other minimally invasive instruments, the positioning of the end effector at the surgical site is constrained by the trocar. Generally the elongate shaft 23 enables the clinician to insert the end effector to a desired depth and rotate the end effector about the longitudinal axis of the shaft. This allows the end effector to be positioned at the surgical site, to a degree. With judicious placement of the trocar and use of graspers, for instance, through another trocar, this amount of positioning is often sufficient. Depending upon the nature of the operation, however, it may be desirable to adjust the positioning of the end effector of an endoscopic surgical instrument. In particular, it is often desirable to orient the end effector at any one of multiple angles relative to the longitudinal axis of the elongate shaft of the instrument.

[0013] Movement of the end effector through multiple angles relative to the instrument shaft is conventionally referred to as “articulation.” Articulation is typically accomplished by a pivot (or articulation) joint being placed in the elongate shaft just proximal to the end effector. This allows the clinician to articulate the end effector remotely to either side for better surgical placement of the staple lines and easier tissue manipulation and orientation. An articulating end effector 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 elongate shaft.

[0014] Approaches to articulating end effectors tend to be complicated because mechanisms for controlling the articulation must be integrated with mechanisms for operating the end effector. For example the closure sleeve, drive member and mechanisms for articulation must be implemented within the small diameter constraints of the instrument's shaft. One common design involves 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.

[0015] While this generally-known approach successfully articulates the end effector about an articulation pivot, it is desirable to further enhance performance. Consequently, a significant need exists for an improved articulating surgical instrument.

[0016] In accordance with one embodiment of the invention, there is provided an articulating surgical instrument. The instrument in this embodiment comprises a shaft and an end effector. The shaft has a longitudinal axis, and the end effector is operationally coupled, preferably mechanically coupled, to the shaft at an articulation pivot. The instrument also comprises a first band operationally connected to the end effector and extending through at least a portion of the shaft. An articulation control applies a force in a direction substantially transverse to the longitudinal axis. The articulation control is operationally connected to the first band such that application of the force is translated through the first band to the end effector to effect rotation of the end effector relative to the shaft about the articulation pivot.

[0017] In accordance with another embodiment having a shaft and end effector as described above, a second band is operationally connected to and extends from the end effector through at least a portion of the shaft. In this embodiment, the articulation control is also configured to apply the force in a second direction substantially transverse to the longitudinal axis. The force is translated through the second band to the end effector to effect rotation of the end effector relative to the shaft about the articulation pivot in a second rotational direction.

[0018] The articulation control in one embodiment may be structured for movement in a first direction for applying the force in a first transverse direction to effect rotation of the end effector in a first rotational direction relative to the shaft. In this embodiment, the articulation control may also be structured for movement in a second direction for applying the force in a second transverse direction, opposite to the first transverse direction, to effect rotation of the end effector in a second rotational direction relative to the shaft.

[0019] The articulation control may include an articulation slide that is movable transversely across the shaft to first, second and neutral positions. The articulation slide defines a slot positioned at about the longitudinal axis when the articulation slide is in the neutral position and the first and second bands pass through the slot. The articulation slot is offset from the longitudinal axis when the articulation slide is in either one of the first or the second positions.

[0020] In various embodiments, the first band and the second band are pre-bent toward the longitudinal axis when the articulation control is in a neutral position, when no force is applied to the articulation control. In yet another embodiment having a shaft and end effector, the first band has a first end mechanically coupled to the end effector at a point offset from the articulation axis.

[0021] In accordance with another embodiment having a shaft and end effector as described above, the instrument has a first hydraulic articulation bladder expandable toward the first band. A hydraulic actuation bladder is fluidically coupled to the first hydraulic articulation bladder. Also, in various embodiments, a first actuation button is positioned to compress the first hydraulic actuation bladder. Compression of the first hydraulic actuation bladder causes the first hydraulic articulation bladder to inflate. Expansion of the first hydraulic articulation bladder toward the first band causes bending of the first band which effects rotation of the end effector relative to the shaft about the articulation pivot in a first rotational direction. In another embodiment of the instrument, a second hydraulic articulation bladder may be provided. Expansion of the second hydraulic articulation bladder toward the second band causes bending of the second band which effects rotation of the end effector relative to the shaft about the articulation pivot in a second rotational direction.

[0022] In accordance with another embodiment of the invention, there is provided a method for operating the instrument. The method may comprise the step of applying a force to the instrument in a direction that is substantially transverse to the shaft, wherein the force causes the first band to bend, and wherein the bending of the first band causes the end effector to pivot relative to the shaft about the articulation pivot in a first direction.

[0055] FIGS. 3-5 show an exemplary surgical instrument 100 generally including a handle 103, a shaft 104 and an articulating end effector 102 pivotally connected to the shaft 104 at articulation pivot 110. An articulation control 112 is provided to effect rotation of the end effector 102 about articulation pivot 110. The end effector 102 is shown configured to act as an endocutter for clamping, severing and stapling tissue, however, it will be appreciated that various embodiments of the present invention may include end effectors (not shown) configured to act as other surgical devices including, for example, graspers, cutters, staplers, clip appliers, access devices, drug/gene therapy delivery devices, ultrasound, RF, or laser energy devices, etc.

[0056] The handle 103 of the instrument 100 may include closure trigger 114 and firing trigger 116 for actuating the end effector 102. 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 an end effector. The end effector 102 is shown separated from a handle 103 by the preferably elongate shaft 104. A clinician may articulate the end effector 102 relative to the shaft 104 by utilizing the articulation control 112.

[0057] It should be appreciated that spatial terms such as vertical, horizontal, right, left etc., are given herein with reference to the figures assuming that the longitudinal axis of the surgical instrument 100 is co-axial to the central axis of the shaft 104, with the triggers 114, 116 extending downwardly at an acute angle from the bottom of the handle 103. In actual practice, however, the surgical instrument 100 may be oriented at various angles and as such these spatial terms are used relative to the surgical instrument 100 itself. Further, proximal is used to denote a perspective of a clinician who is behind the handle 103 who places the end effector 102 distal, or away from him or herself.

[0058] As used herein, the term “fluidically coupled” means that the elements are coupled together with an appropriate 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,” “hydraulic line” or “return line” refers to an appropriate fluid passage formed from conduit, pipe, tubing, etc. for transporting pressurized hydraulic fluid from one component to another.

[0059] As used herein, the term, “hydraulic fluid” refers to any fluid suitable for use in a hydraulic system. Non-limiting examples of hydraulic fluids include oil, air, etc. In one non-limiting embodiment, hydraulic fluids may be biocompatable fluids including, for example, glycerin oil, saline, etc.

[0060] As used herein, the phrase, “substantially transverse to the longitudinal axis” where the “longitudinal axis” is the axis of the shaft, refers to a direction that is nearly perpendicular to the longitudinal axis. It will be appreciated, however, that directions that deviate some from perpendicular to the longitudinal axis are also substantially transverse to the longitudinal axis.

[0061] Various embodiments of the present invention are directed to instruments having an articulation pivot driven by bending cables or bands. FIG. 6 shows a cross-sectional top down view of an exemplary elongate shaft 104 and end effector 102 including a bending band driven articulation pivot 110. In the non-limiting embodiment of FIG. 6, band 205 is mechanically coupled to boss 206 located at the articulation pivot 110. The band 205 may include band portions 202 and 204 extending proximally from the boss 206 along the elongate shaft 104 and through the articulation control 112. The band 205 and band portions 202, 204 are preferably of a fixed length

[0062] FIG. 7 shows a cross-sectional view of the articulation pivot 110 shown in FIG. 6 including the boss 206 and band 205. The band 205 may be mechanically coupled to the boss 206 as shown using any suitable fastening method including, for example, glue, welding, etc. In various embodiments, each band portion 202, 204 may be provided as a separate band, with each separate band having one end mechanically coupled to the boss 206 and another end extending through the shaft 104 and articulation controller 112 (not shown in FIG. 7). The separate bands may be mechanically coupled to the boss 206 as described above.

[0063] Band portions 202, 204 may extend from the boss 206, through the articulation pivot 110 and along the shaft 104 to the articulation control 112, shown in FIG. 8. The articulation control 112 may include an articulation slide 208, a frame 212 and an enclosure 218. Band portions 202, 204 may pass through the articulation slide 208 by way of slot 210 or other aperture, although it will be appreciated that the band portions 202, 204 may be coupled to the slide 208 by any suitable means. The articulation slide 208 may be one piece, as shown in FIG. 8, or may in one non-limiting embodiment, include two pieces with an interface between the two pieces defining the slot 210. In one non-limiting embodiment, the articulation slide 208 may include multiple slots, for example, with each slot corresponding to one of band portions 202, 204. Enclosure 218 may cover the various components of the control 112 to prevent debris from entering.

[0064] In various embodiments, band portions 202, 204 may be anchored to the frame 212 at connection points 214, 216 proximally located from the slot 210. The non-limiting embodiment of FIG. 8 shows that the band portions 202, 204 are pre-bent from connection points 214, 216 to the slot 210, located near the longitudinal axis of the shaft 104. It will be appreciated that band portions 202, 204 may be anchored anywhere in the instrument 10 located proximally from the slot 210, including the handle 103.

[0065] FIGS. 9A-11 show views of the end effector 102 and elongate shaft 104 of the instrument 100 including the articulation pivot 110 shown in FIG. 7. The end effector 102 shown in FIGS. 9A-11 is configured to act as an endocutter. It will be appreciated that in various embodiments, the end effector 102 may be configured to perform other surgical tasks, requiring the removal, modification, or addition of components from what is shown in the figures. Also, it will be appreciated that the end effectors 102 shown in FIGS. 3-6, 11 may be customized for specific surgical applications. For example, FIGS. 3-6 and 10-12 show a 45 mm endocutter end effector while FIG. 9A shows a 60 mm endocutter end effector.

[0066] FIG. 9A shows an exploded view of the end effector 102 and elongate shaft 104 including various internal components. An end effector frame 150 and shaft frame 154 are configured to be joined at articulation pivot 110. Boss 206 may be integral to the end effector frame 150 with band 205 interfacing the boss 206 as shown. The shaft frame 154 may include a distally directed tang 302 defining an aperture 304. The aperture 304 may be positioned to interface an articulation pin (not shown) included in end effector frame 150 allowing the end effector frame 150 to pivot relative to the shaft frame 154, and accordingly, the end effector 102 to pivot relative to the shaft 104. When assembled, the various components may pivot about articulation pivot 110 at an articulation axis 306 shown in FIGS. 10 and 11.

[0067] FIG. 9A also shows an anvil 120. In this non-limiting embodiment, the anvil 120 is coupled to the elongate channel 198. For example, apertures 199 of the elongate channel 198 may receive pins 152 of the anvil 120, allowing the anvil 120 to pivot from an open position to a closed position relative to the elongate channel 198 and staple cartridge 118. A spring clip 158 is mounted in the end effector frame 150 as a lockout for firing bar 172. Distal and proximal square apertures 164, 168 formed on top of the end effector frame 150 may define a clip bar 170 therebetween that receives a top arm 162 of a clip spring 158 whose lower, distally extended arm 160 asserts a downward force on a raised portion 174 of the firing bar 172 discussed below. It will be appreciated that various embodiments may include other types of lockouts or no lockouts at all.

[0068] In addition, FIG. 9A shows the firing bar 172, configured to longitudinally translate through the shaft frame 154, through the flexible closure and pivoting frame articulation joint 110, and through a firing slot 176 in the distal frame ground 150 into the end effector 102. The firing bar 172 may be constructed from one solid section, or in various embodiments, may include a laminate material comprising, for example, a stack of steel plates 173 as shown in FIG. 9B. It will be appreciated that a firing bar 172 made from a laminate material may lower the force required to articulate the end effector 102. A distally projecting end of the firing bar 172 is attached to an E-beam 178 that assists in spacing the anvil 120 from the staple cartridge 118 when the anvil 120 is in a closed position. Sharpened cutting edge 182 of the E-beam 178 may also be used to sever tissue.

[0069] In operation, the E-beam 178 actuates the staple cartridge 118. The staple cartridge 118 includes a molded cartridge body 194 that holds a plurality of staples 191 resting upon staple drivers 192 within respective upwardly open staple apertures 195. A wedge sled 190 is driven distally by the E-beam 178, sliding upon a cartridge tray 196 that holds together the various components of the replaceable staple cartridge 118. The wedge sled 190 upwardly cams the staple drivers 192 to force out the staples 191 into deforming contact with the anvil 120 while a cutting surface 182 of the E-beam 178 severs clamped tissue.

[0070] In the figures, the firing bar 172 is shown positioned within the shaft 104 such that it passes through the cartridge 194 when the instrument 100 is fired. In one non-limiting embodiment, the firing bar 172 is instead positioned within the shaft 104 such that all or a portion of the body of the firing bar element 172 is supported by a slot (not shown) in the anvil 120 during firing. Because the anvil 120 may be stronger than the cartridge 118, support from the slot may preventing the firing bar 172 from buckling, even when high loads are applied to the distal end of the firing bar 178. This may be useful in embodiments where the firing bar element 172 includes laminate plates 173.

[0071] It should be appreciated that upper pins 180 of the E-beam 178 engage the anvil 120 during firing while middle pins 184 and a bottom foot 186 engage various portions of the cartridge body 194, cartridge tray 196 and elongate channel 198. In use, slot 193 of the cartridge body 194 aligns with slot 197 of the cartridge tray 196 and with slot 189 of the elongate channel 198. The leading edge of E-beam 178 slides through the aligned slots 193, 197, and 189. As indicated in FIG. 9A, the bottom foot 186 engages a groove running along the bottom surface of channel 198 along the length of slot 189. The middle pins 184 engage the top surfaces of cartridge tray 196 along the length of longitudinal slot 197. The foot 186 is braced against the bottom of channel 198 and the upper pins 180 are braced in a groove in the bottom surface of the anvil 120 to prevent the anvil 120 and channel 198 from being forced apart from resistance of tissue as the end effector is advanced by the clinician or surgeon during use. Thereafter, the firing bar 172 is retracted proximally, retracting as well the E-beam 178, allowing the anvil 120 to be opened to release the two stapled and severed tissue portions (not shown).

[0072] FIGS. 9A-11 also show a double pivot closure sleeve assembly 121 according to various embodiments of the present invention. It will be appreciated that the invention is not limited to a double pivot closure sleeve design and may include any suitable closure sleeve, or no closure sleeve at all. With particular reference to FIG. 9A, the double pivot closure sleeve assembly 121 includes a shaft closure tube section 128 having upper and lower distally projecting tangs 146, 148. An end effector closure tube section 126 includes a horseshoe aperture 124 and tab 123 for engaging the opening tab 122 on the anvil 120. The horseshoe aperture 124 and tab 123 engage tab 122 when the anvil 120 is opened. The closure tube section 126 is shown having upper 144 and lower (not visible) proximally projecting tangs. An upper double pivot link 130 includes upwardly projecting distal and proximal pivot pins 134, 136 that engage respectively an upper distal pin hole 138 in the upper proximally projecting tang 144 and an upper proximal pin hole 140 in the upper distally projecting tang 146. A lower double pivot link 132 includes downwardly projecting distal and proximal pivot pins (not shown in FIG. 9A, but see FIG. 10) that engage respectively a lower distal pin hole in the lower proximally projecting tang and a lower proximal pin hole 142 in the lower distally projecting tang 148.

[0073] In use, the closure sleeve assembly 121 is translated distally to close the anvil 120, for example, in response to the actuation of the closure trigger 114. The anvil 120 is closed by distally translating the closure tube section 126, and thus the sleeve assembly 121, causing it to strike a proximal surface on the anvil 120 located in FIG. 9A to the left of the tab 122. As shown more clearly in FIGS. 10 and 11, the anvil 120 is opened by proximally translating the tube section 126, and sleeve assembly 121, causing tab 123 and the horseshoe aperture 124 to contact and push against the tab 122 to lift the anvil 120. In the anvil-open position, the double pivot closure sleeve assembly 121 is moved to its proximal position.

[0074] In operation, the clinician may articulate the end effector 102 of the instrument 100 relative to the shaft 104 about pivot 110 by pushing the control 112 laterally. Referring to FIGS. 6 and 8, it will be appreciated that if the band portions 202, 204 are of a fixed length and were to remain taut during articulation, then transverse force provided by the articulation control may not cause bending because, for example, band portion 204 would prevent the end effector 102 from rotating as the band portion 202 was bent. Accordingly, in the non limiting embodiment shown in FIG. 8, the band 205 is constructed such that band portions 202 and 204 are slightly longer than they need to be to articulate the end effector 102. The band portions 202, 204 are then pre-bent toward the slot 210, which is in line with longitudinal axis of the shaft 104 when the end effector 102 is in a neutral position.

[0075] From the neutral position, the clinician may articulate the end effector 102 to the left relative to the shaft 104 by providing a lateral force to the left side of the control 112. In response to force, the articulation slide 208 may be pushed through the frame 212 as shown in FIGS. 12 and 13. As the slide 208 is pushed through the frame 212, the slot 210 as well as band portion 204 may be translated across the elongate shaft 104 in a transverse direction, for example, a direction substantially transverse, or perpendicular, to the longitudinal axis of the shaft 104. Accordingly, a force is applied to band portion 204, causing it to further bend from its initial pre-bent position toward the opposite side of the shaft 104. At the same time, band portion 202 is relaxed from its initial pre-bent position. The further bending of band portion 204 coupled with the straightening of band portion 202 causes a counter-clockwise rotational force at boss 206, which in turn causes the boss 206 and end effector 102 to pivot to the left about the articulation pivot 110 to a desired angle relative to the axis of the shaft 104 as shown in FIG. 12. The relaxation of band portion 202 decreases the tension on that band portion, allowing the band portion 204 to articulate the end effector 102 without interference from the band portion 202. It will be appreciated that the clinician may also articulate the end effector 102 to the right relative to the shaft 104 by providing a lateral force to the right side of the control 112. This bends cable portion 202, causing a clockwise rotational force at boss 206 which, in turn, causes the boss 206 and end effector to pivot to the right about articulation pivot 110.

[0076] FIGS. 14-18 illustrate an additional embodiment for articulating the end effector 102 with bending bands according to various embodiments. It will be appreciated that any kind of end effector 102 may be used with the embodiments shown in FIGS. 14-18. For example, FIGS. 14 and 16-18 show all or part of a 45 mm endocutter end effector while FIG. 15 shows a 60 mm endocutter end effector. FIG. 14 shows a cross-sectional view of the articulation pivot 110 including bands 401, 403 and boss 406. The bands 401, 403 may extend distally toward the articulation pivot 110 as shown. Band 401 may extend through the shaft 104 along its left side where it is routed around band member 402 and across to the right side of the shaft 104. There, the band 401 may be mechanically coupled to boss 406, for example, at connection point 408. Likewise, band 403 may extend through the shaft 104 along its right side where it is routed around band member 404 and across to the left side of the shaft. There, band 403 may be mechanically coupled to the boss 406 at connection point 410.

[0077] FIG. 16 shows a side cross-sectional view of the pivot 110. Bands 401 and 403 are shown offset from one another to prevent interference in movement according to one non-limiting embodiment. For example, band 401 is shown at a lower position than band 403. In another non-limiting embodiment, the vertical positioning of bands 401 and 403 may be reversed. FIG. 15 shows an exploded view of the end effector 102 and shaft 104 including internal components. The end effector 102 shown in FIG. 15 is configured to act as an endocutter for clamping, stapling, and severing tissue, however, it will be appreciated that various embodiments may utilize end effectors (not shown) directed to other surgical tasks. Band members 402, 404 are shown attached to shaft frame tang 302. Also, boss 406 may include connection points 408, 410 as shown. When assembled, the various components may pivot about articulation pivot 110 at an articulation axis 306 shown in FIG. 16.

[0078] In use, the embodiment of FIG. 14 may have an unarticulated position as shown in FIG. 17. The articulation control 112 and bands 401, 403 are shown in a centered position roughly at the longitudinal axis of the shaft 104. Accordingly, the end effector 102 is in a neutral or unarticulated position. In FIG. 18, the articulation control 112 is shown with the articulation slide 208 pushed through the articulation frame to the right side of the shaft 104. Accordingly, bands 401 and 403 are bent toward the right side of the shaft 104. It can be seen that the bending of band 401 to the right exerts a laterally directed force on the boss 406 that is offset from the boss's 406 pivot point. This offset force causes the boss 406 to rotate about articulation pivot 110, in turn causing the end effector 102 to pivot to the right as shown. It will be appreciated that pushing the articulation slide 208 to the left side of the shaft 104 may exert a laterally directed force on bands 401 and 403, bending both bands 401, 403 toward the left side of the shaft 104. The bending of band 403 then exerts a laterally directed force on boss 406, which as above, is offset from the boss's 406 pivot point. This, in turn, causes the boss 406 to rotate about the articulation pivot causing the end effector 102 to pivot to the left.

[0079] FIGS. 19-24 show another embodiment for articulating the end effector 102 with bands 252, 254 oriented to interface with the articulation control 112 at points offset from the longitudinal axis of the shaft 104. Accordingly, the bands 252, 254 are substantially more parallel to each other within the shaft 104 than band portions 202, 204 or bands 401, 403 shown in FIGS. 6 and 17 respectively. FIG. 19 shows a top-down cross section of an exemplary shaft 104, end effector 102 and articulation control 112 according to the embodiment of FIGS. 19-24. The bands 252, 254 are shown extending from a boss 256 through the shaft 104 to the articulation control 112. Spring assemblies 258 and 260 are included along the length of bands 252, 254 allowing the bands to lengthen. It will be appreciated that bands 252, 254 may be separate bands, similar to, for example, bands 401, 403 shown in FIGS. 14-18, or may be one band with two portions similar to band 205 and band portions 202, 204 shown in FIGS. 6-13. Similarly, it will be appreciated that the bands 252, 254 may be routed from the boss 256 around band members (not shown) similar to band members 402, 404 shown in FIGS. 14-18.

[0080] FIG. 20 shows a top-down cross section of an exemplary interface between the shaft 104 and articulation control 112 according to the embodiment of FIGS. 19-24. Bands 252, 254 may extend through the shaft 104 and interface the articulation control 112 at slide opening 262 of articulation slide 280 before being anchored to the articulation control 112 at connection points 214, 216. The bands 252, 254 may be pre-bent between the slide opening 262 and connection points 214 and 216. It will be appreciated, however, that because the bands 252, 254 interface the articulation control 112 at points offset from the center of the shaft 104, they are not pre-bent to the same degree as the band portions 202 or 204 shown in FIG. 8.

[0081] FIG. 21 shows a close-up cross sectional view of spring assemblies 258, 260. The spring assemblies 258 and 260 are configured to allow the bands 252, 254 to lengthen under low tension, but arrest the expansion of the bands 252, 254 under high tension. Referring to the spring assemblies 258, 260, a piston 272 rides within a shell 270. A spring 274 is coupled to the piston 272 as well as the shell 270. When the cable 252 or 254 is under a slight tension, then the spring 274 will lengthen slightly, allowing the piston 272 to move toward the opening 271 of the shell 270. When the cable 252 or 254 is under a greater tension, then the piston 272 will be moved into contact with the shell 270 near opening 271, preventing the spring assembly 258 or 260 from lengthening any further.

[0082] FIG. 22 shows the articulation control 112 of FIG. 20 with the articulation slide 280 pushed from left to right across the longitudinal axis of the shaft 104. As a result, band 252 is bent toward the right side of the shaft 104, while band 254 is maintained in its original position by stop 282. Referring to FIG. 24, as the band 252 is initially bent by articulation control 112, the spring 274 of spring assembly 258 will lengthen until the piston 272 contacts the shell 270 and the spring assembly 258 can lengthen no more. At that point, continued bending of the cable 252 causes a counter-clockwise rotational force at the boss 256. As the boss 256 begins to rotate in response to the rotational force, it exerts a tension on the unbent band 254. Accordingly, the spring 274 of the spring assembly 260 may lengthen, lengthening band 254 and allowing the boss 256 to rotate in a counter-clockwise direction. The rotation of the boss 256 causes the end effector 102 to pivot to the leftward rotational direction, as shown in FIG. 23. It will be appreciated that the tension in band 254 is low enough that the spring assembly 260 will not reach its maximum expansion during the desired range of motion of the end effector 102.

[0083] Sliding the articulation slide 280 across the shaft 104 from right to left, the opposite of what is shown in FIGS. 22-24, causes band 254 to bend and effect a clockwise rotation of the boss 256 and rightward articulation of the end effector 102 with the roles of bands 252 and 254 reversed from the description above. Also, it will be appreciated that in various applications, it may only be necessary for the end effector 102 to pivot in one rotational direction relative to the shaft. Accordingly, the embodiment of FIGS. 19-24 may be implemented with only one spring assembly positioned on the band opposite the desired direction of articulation. The spring assembly, in that case, may be any kind of spring including, for example, an elastic portion of the appropriate band.

[0084] FIGS. 25-30 show an embodiment for hydraulically articulating the end effector 102 with bending cables or bands according to various embodiments. It will be appreciated that any kind of end effector 102 may be used with the embodiments shown in FIGS. 25-30. For example, FIGS. 25-26 and 29-30 show all or part of a 45 mm endocutter end effector while FIG. 27 shows a 60 mm endocutter end effector. Referring to FIG. 25, a member 508 is shown mechanically coupled to the end effector 102. The member 508 may be pivotally connected to shaft 104 at pin 522 in a manner allowing the end effector 102 and member 508 to pivot about the pin 522. The pin 522 may, in various embodiments, be located at the articulation axis 306 (shown in FIG. 26).

[0085] Bands 502, 504 may be coupled to the member 508, for example, at connection points 507 and 509 respectively. It will be appreciated that in various non-limiting embodiments, bands 502, 504 may be replaced with one band (not shown) that extends around member 508, for example, similar to the embodiment shown in FIG. 7 above. Referring back to FIG. 25, bands 502 and 504 may extend from the member 508 to connection points 513 and 511 respectively on the right side of the shaft 104. Each of the bands 502, 504, are also be positioned to be in effective contact with a respective hydraulic bladder 510, 512 as shown.

[0086] The bladders 510, 512 may expand proximally when supplied with pressurized hydraulic fluid, for example, through hydraulic lines 514 and 516. When expanded, bladders 510, 512 exert a proximal bending force on bands 502, 504. For example, when expanded, bladder 510 exerts a bending force on band 504, which in turn exerts a force offset to the member 508's pivot point, rotating the end effector 102 about the articulation axis 306 (shown in FIG. 26). In the embodiment shown in FIGS. 25-27 and 29-30, the bladders 510, 512 are both positioned on the right side of the shaft 104. It will be appreciated, however, that in other non-limiting embodiments, the bladders may be placed on the left side of the shaft 104, or each bladder 510, 512 may be placed on a different side of the shaft 104. Expansion of the bladders 510, 512 upon pressurization may be in any of several directions provided the expansion exerts a force against the band 502 or 504, with which the bladder is in effective contact, to effect the rotational force on the member 508 and end effector 102.

[0087] FIGS. 26-27 show additional views of the end effector 102 and shaft 104 according to the embodiment of FIG. 25. FIG. 27 shows an exploded view of components present in the end effector 102 and shaft 104. End effector frame 150 is shown mechanically coupled to member 508. In various non-limiting embodiments, the member 508 may be an integral portion of the end effector frame 150. A shaft frame 526 is shown to include pin aperture 520. Pin 522 may engage pin aperture 518, defined by member 508, thereby fastening member 508 to the shaft frame 526 and allowing the member 508 and end effector 102 to rotate about pin 522. The shaft frame 526 is also shown to include hydraulic bladder pockets 540 and 542 for enclosing hydraulic bladders 510 and 512, respectively.

[0088] The hydraulic bladders 510 and 512 may be operated using the articulation control 501 shown in FIG. 28. Left and right actuation bladders 528, 530 included in articulation control 501, when actuated, provide pressurized hydraulic fluid to hydraulic lines 514, 516. The actuation bladders 528, 530 may be enclosed in a frame assembly including a top portion 532 and a bottom portion 534. Left and right buttons 536, 538 included in the frame assembly allow a clinician to compress one or the other of hydraulic bladders 528 or 530, thus actuating the hydraulic bladder 528 or 530 thereby forcing the hydraulic fluid from the bladder through its associated hydraulic line 514, 516 to the bladders 512 or 510 respectively, thus bringing about rotation of the end effector 102.

[0089] FIGS. 29-30 show cross-sectional views of the embodiment of FIG. 25 in use. In FIG. 29, neither the bladder 510 nor the bladder 512 is expanded. Accordingly, the end effector 102 is shown in a neutral or unarticulated position. In contrast, FIG. 30 shows the bladder 510 in an inflated state. The bladder 510 inflates, for example, in response to pressurized hydraulic fluid provided through hydraulic line 516. In its inflated state, the bladder 510 is expanded to provide a bending force to band 504. The band 504 then exerts a force offset to the member's 508 pivot point to rotate the member 508 in a clockwise rotational direction, causing the end effector 102 to articulate to the right as shown.

[0090] 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.

[0091] For example, although the embodiments described above have advantages for an endoscopically employed surgical severing and stapling instrument 100, a similar embodiments may be used in other clinical procedures. It is generally accepted that endoscopic procedures are more common than laparoscopic procedures. 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 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.

[0092] For yet another example, although an illustrative handle portion 103 described herein is operated mechanically in response to input from a clinician, it is consistent with aspects of the invention for some or all of the functions of a handle portion to be powered by other means (e.g., pneumatic, electromechanical, ultrasonic, hydraulic, etc.). Furthermore, controls of each of these functions may be manually presented on a handle portion or be remotely controlled (e.g., wireless remote, automated remote console, etc.).

[0093] Any patent, publication, or information, 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 document. As such the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference.