TECHNICAL FIELD

[0001] The present disclosure relates to surgical instruments and, in various circumstances, to surgical stapling and cutting instruments and staple cartridges therefor that are designed to staple and cut tissue.

BACKGROUND

[0002] In a motorized surgical stapling and cutting instrument it may be useful to measure the position and velocity of a cutting member in an initial predetermined time or displacement to control speed. Measurement of position or velocity over an initial predetermined time or displacement may be useful to evaluate tissue thickness and to adjust the speed of the remaining stroke based on this comparison against a threshold.

[0003] While several devices have been made and used, it is believed that no one prior to the inventors has made or used the device described in the appended claims.

SUMMARY

[0004] In one aspect of the present disclosure, a slip ring assembly is used with a surgical shaft assembly. The slip ring assembly includes a first housing portion, a first connector supported in the first housing portion, and a first conductor mounted on the first connector. The slip ring assembly also includes a second housing portion, wherein one of the first housing portion and the second housing portion is rotatable relative to the other, a second connector supported in the second housing portion, and a second conductor mounted on the second connector, wherein the second conductor is in contact with the first conductor. An interface between the first housing portion and the second housing portion, wherein the interface is configured to effect a seal between the first housing portion and the second housing portion.

[0005] In one aspect of the present disclosure, a surgical shaft assembly is used with a surgical instrument. The shaft assembly includes a housing that has a proximal housing portion and a distal housing portion rotatable relative to the proximal housing portion. The shaft assembly also includes a slip ring assembly that has a proximal connector supported in the proximal housing portion, a plurality of first conductors mounted on the proximal connector, a distal connector supported in the distal housing portion, and a plurality of second conductors mounted on the distal connector, wherein the second conductors are rotatable relative to the first conductors and are in contact therewith. The proximal housing portion and the distal housing portion are configured to resist water ingress into the housing.

[0006] In one aspect of the present disclosure, a slip ring assembly is used with a surgical shaft assembly. The slip ring assembly includes a first housing portion, a slip ring supported in the first housing portion, a first conductor mounted on the slip ring, a second housing portion, a commutator supported in the second housing portion, and a second conductor mounted on the commutator, wherein the second conductor is rotatable relative to the first conductor and is in contact therewith. The first housing portion and the second housing portion are configured to form a watertight barrier around the first and second conductors.

FIGURES

[0007] The novel features of the various aspects described herein are set forth with particularity in the appended claims. The various aspects, however, both as to organization and methods of operation may be better understood by reference to the following description, taken in conjunction with the accompanying drawings as follows:

[0008] FIG. 1 is a perspective view of a surgical instrument that has a shaft assembly and an end effector in accordance with one or more aspects of the present disclosure.

[0009] FIG. 2 is an exploded assembly view of a portion of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

[0010] FIG. 3 is an exploded view of an end effector of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

[0011] FIG. 4 is perspective view of an RF cartridge and an elongate channel adapted for use with the RF cartridge according to one aspect of the present disclosure.

[0012] FIG. 5 is an exploded assembly view of portions of the interchangeable shaft assembly of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

[0013] FIG. 6 is another exploded assembly view of portions of the interchangeable shaft assembly of FIG. 1 according to one aspect of this disclosure.

[0014] FIG. 7 is a cross-sectional view of a portion of the interchangeable shaft assembly of FIG. 1 according to one aspect of this disclosure.

[0015] FIG. 8 is a perspective view of a portion of the shaft assembly of FIG. 1 with the switch drum omitted for clarity. [0016] FIG. 9 is another perspective view of the portion of the interchangeable shaft assembly of FIG. 1 with the switch drum mounted thereon.

[0017] FIG. 10 is an unassembled perspective view of a slip ring assembly according to one aspect of this disclosure.

[0018] FIG. 1 1 is an assembled perspective view of the slip ring assembly of FIG. 10.

[0019] FIG. 12 is an unassembled cross-sectional view of the slip ring assembly of FIG. 10.

[0020] FIG. 13 is an assembled cross-sectional view of the slip ring assembly of FIG. 10.

[0021] FIG. 14 is a cross-sectional view of a proximal portion of the slip ring assembly of FIG. 10.

DESCRIPTION

[0022] Applicant of the present application owns the following U.S. Patent Applications that were filed on even date herewith and which are each herein incorporated by reference in their respective entireties:

U.S. Patent Application Serial No. entitled ARTICULATION STATE

DETECTION MECHANISMS; Attorney Docket No. END8176USNP/170049;

U.S. Patent Application Serial No. entitled SURGICAL SHAFT

ASSEMBLIES WITH INCREASED CONTACT PRESSURE; Attorney Docket No.

END8177USNP/170050;

U.S. Patent Application Serial No. entitled SURGICAL SHAFT

ASSEMBLIES WITH SLIP RING ASSEMBLIES FORMING CAPACITIVE CHANNELS; Attorney Docket No. END8178USNP/170051 ;

U.S. Patent Application Serial No. entitled METHOD OF COATING SLIP

RINGS; Attorney Docket No. END8179USNP/170052M; and

U.S. Patent Application Serial No. entitled SURGICAL SHAFT

ASSEMBLIES WITH FLEXIBLE INTERFACES; Attorney Docket No. END8223USNP/170126.

[0023] Certain aspects are shown and described to provide an understanding of the structure, function, manufacture, and use of the disclosed devices and methods. Features shown or described in one example may be combined with features of other examples and modifications and variations are within the scope of this disclosure.

[0024] The terms "proximal" and "distal" are relative to a clinician manipulating the handle of the surgical instrument where "proximal" refers to the portion closer to the clinician and "distal" refers to the portion located further from the clinician. For expediency, spatial terms "vertical," "horizontal," "up," and "down" used with respect to the drawings are not intended to be limiting and/or absolute, because surgical instruments can used in many orientations and positions. [0025] The terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has" and "having"), "include" (and any form of include, such as "includes" and "including") and "contain" (and any form of contain, such as "contains" and "containing") are open-ended linking verbs. As a result, a surgical system, device, or apparatus that "comprises," "has," "includes" or "contains" one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, an element of a system, device, or apparatus that "comprises," "has," "includes" or "contains" one or more features possesses those one or more features, but is not limited to possessing only those one or more features.

[0026] Example devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. Such devices and methods, however, can be used in other surgical procedures and applications including open surgical procedures, for example. The surgical instruments can be inserted into a through a natural orifice or through an incision or puncture hole formed in tissue. The working portions or end effector portions of the instruments can be inserted directly into the body or through an access device that has a working channel through which the end effector and elongated shaft of the surgical instrument can be advanced.

[0027] FIGS. 1 -9 depict a motor-driven surgical instrument 10 for cutting and fastening that may or may not be reused. In the illustrated examples, the surgical instrument 10 includes a housing 12 that comprises a handle assembly 14 that is configured to be grasped, manipulated, and actuated by the clinician. The housing 12 is configured for operable attachment to an interchangeable shaft assembly 200 that has an end effector 300 operably coupled thereto that is configured to perform one or more surgical tasks or procedures. In accordance with the present disclosure, various forms of interchangeable shaft assemblies may be effectively employed in connection with robotically controlled surgical systems. The term "housing" may encompass a housing or similar portion of a robotic system that houses or otherwise operably supports at least one drive system configured to generate and apply at least one control motion that could be used to actuate interchangeable shaft assemblies. The term "frame" may refer to a portion of a handheld surgical instrument. The term "frame" also may represent a portion of a robotically controlled surgical instrument and/or a portion of the robotic system that may be used to operably control a surgical instrument. Interchangeable shaft assemblies may be employed with various robotic systems, instruments, components, and methods disclosed in U.S. Patent No. 9,072,535, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, which is herein incorporated by reference in its entirety. [0028] FIG. 1 is a perspective view of a surgical instrument 10 that has an interchangeable shaft assembly 200 operably coupled thereto according to one aspect of this disclosure. The housing 12 includes an end effector 300 that comprises a surgical cutting and fastening device configured to operably support a surgical staple cartridge 304 therein. The housing 12 may be configured for use in connection with interchangeable shaft assemblies that include end effectors that are adapted to support different sizes and types of staple cartridges, have different shaft lengths, sizes, and types. The housing 12 may be employed with a variety of

interchangeable shaft assemblies, including assemblies configured to apply other motions and forms of energy such as, radio frequency (RF) energy, ultrasonic energy, and/or motion to end effector arrangements adapted for use in connection with various surgical applications and procedures. The end effectors, shaft assemblies, handles, surgical instruments, and/or surgical instrument systems can utilize any suitable fastener, or fasteners, to fasten tissue. For instance, a fastener cartridge comprising a plurality of fasteners removably stored therein can be removably inserted into and/or attached to the end effector of a shaft assembly.

[0029] The handle assembly 14 may comprise a pair of interconnectable handle housing segments 16, 18 interconnected by screws, snap features, adhesive, etc. The handle housing segments 16, 18 cooperate to form a pistol grip portion 19 that can be gripped and manipulated by the clinician. The handle assembly 14 operably supports a plurality of drive systems configured to generate and apply control motions to corresponding portions of the

interchangeable shaft assembly that is operably attached thereto.

[0030] FIG. 2 is an exploded assembly view of a portion of the surgical instrument 10 of FIG. 1 according to one aspect of this disclosure. The handle assembly 14 may include a frame 20 that operably supports a plurality of drive systems. The frame 20 can operably support a "first" or closure drive system 30, which can apply closing and opening motions to the interchangeable shaft assembly 200. The closure drive system 30 may include an actuator such as a closure trigger 32 pivotally supported by the frame 20. The closure trigger 32 is pivotally coupled to the handle assembly 14 by a pivot pin 33 to enable the closure trigger 32 to be manipulated by a clinician. When the clinician grips the pistol grip portion 19 of the handle assembly 14, the closure trigger 32 can pivot from a starting or "unactuated" position to an "actuated" position and more particularly to a fully compressed or fully actuated position.

[0031] The handle assembly 14 and the frame 20 may operably support a firing drive system 80 configured to apply firing motions to corresponding portions of the interchangeable shaft assembly attached thereto. The firing drive system 80 may employ an electric motor 82 located in the pistol grip portion 19 of the handle assembly 14. The electric motor 82 may be a DC brushed motor having a maximum rotational speed of approximately 25,000 RPM, for example. In other arrangements, the motor may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. The electric motor 82 may be powered by a power source 90 that may comprise a removable power pack 92. The removable power pack 92 may comprise a proximal housing portion 94 configured to attach to a distal housing portion 96. The proximal housing portion 94 and the distal housing portion 96 are configured to operably support a plurality of batteries 98 therein. Batteries 98 may each comprise, for example, a Lithium Ion (LI) or other suitable battery. The distal housing portion 96 is configured for removable operable attachment to a control circuit board 100, which is operably coupled to the electric motor 82. Several batteries 98 connected in series may power the surgical instrument 10. The power source 90 may be replaceable and/or rechargeable.

[0032] The electric motor 82 can include a rotatable shaft (not shown) that operably interfaces with a gear reducer assembly 84 mounted in meshing engagement with a with a set, or rack, of drive teeth 122 on a longitudinally movable drive member 120. The longitudinally movable drive member 120 has a rack of drive teeth 122 formed thereon for meshing engagement with a corresponding drive gear 86 of the gear reducer assembly 84.

[0033] In use, a voltage polarity provided by the power source 90 can operate the electric motor 82 in a clockwise direction wherein the voltage polarity applied to the electric motor by the battery can be reversed in order to operate the electric motor 82 in a counter-clockwise direction. When the electric motor 82 is rotated in one direction, the longitudinally movable drive member 120 will be axially driven in the distal direction "DD." When the electric motor 82 is driven in the opposite rotary direction, the longitudinally movable drive member 120 will be axially driven in a proximal direction "PD." The handle assembly 14 can include a switch that can be configured to reverse the polarity applied to the electric motor 82 by the power source 90. The handle assembly 14 may include a sensor configured to detect the position of the longitudinally movable drive member 120 and/or the direction in which the longitudinally movable drive member 120 is being moved.

[0034] Actuation of the electric motor 82 can be controlled by a firing trigger 130 that is pivotally supported on the handle assembly 14. The firing trigger 130 may be pivoted between an unactuated position and an actuated position.

[0035] Turning back to FIG. 1 , the interchangeable shaft assembly 200 includes an end effector 300 comprising an elongated channel 302 configured to operably support a surgical staple cartridge 304 therein. The end effector 300 may include an anvil 306 that is pivotally supported relative to the elongated channel 302. The interchangeable shaft assembly 200 may include an articulation joint 270. Construction and operation of the end effector 300 and the articulation joint 270 are set forth in U.S. Patent Application Publication No. 2014/0263541 , entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, which is herein incorporated by reference in its entirety. The interchangeable shaft assembly 200 may include a proximal housing or nozzle 201 comprised of nozzle portions 202, 203. The interchangeable shaft assembly 200 may include a closure tube 260 extending along a shaft axis SA that can be utilized to close and/or open the anvil 306 of the end effector 300.

[0036] Turning back to FIG. 1 , the closure tube 260 is translated distally (direction "DD") to close the anvil 306, for example, in response to the actuation of the closure trigger 32 in the manner described in the aforementioned reference U.S. Patent Application Publication No. 2014/0263541 . The anvil 306 is opened by proximally translating the closure tube 260. In the anvil-open position, the closure tube 260 is moved to its proximal position.

[0037] FIG. 3 is an exploded view of one aspect of an end effector 300 of the surgical instrument 10 of FIG. 1 in accordance with one or more aspects of the present disclosure. The end effector 300 may include the anvil 306 and the surgical staple cartridge 304. In this non- limiting example, the anvil 306 is coupled to an elongated channel 302. For example, apertures 199 can be defined in the elongated channel 302 which can receive pins 152 extending from the anvil 306 and allow the anvil 306 to pivot from an open position to a closed position relative to the elongated channel 302 and surgical staple cartridge 304. A firing bar 172 is configured to longitudinally translate into the end effector 300. The firing bar 172 may be constructed from one solid section, or in various examples, may include a laminate material comprising, for example, a stack of steel plates. The firing bar 172 comprises an E-beam 178 and a cutting edge 182 at a distal end thereof. In various aspects, the E-beam may be referred to as an I- beam. A distally projecting end of the firing bar 172 can be attached to the E-beam 178 element in any suitable manner and can, among other things, assist in spacing the anvil 306 from a surgical staple cartridge 304 positioned in the elongated channel 302 when the anvil 306 is in a closed position. The E-beam 178 also can include a sharpened cutting edge 182 that can be used to sever tissue as the E-beam 178 is advanced distally by the firing bar 172. In operation, the E-beam 178 also can actuate, or fire, the surgical staple cartridge 304. The surgical staple cartridge 304 can include a molded cartridge body 194 that holds a plurality of staples 191 resting upon staple drivers 192 within respective upwardly open staple cavities 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 surgical staple cartridge 304. The wedge sled 190 upwardly cams the staple drivers 192 to force out the staples 191 into deforming contact with the anvil 306 while the cutting edge 182 of the E-beam 178 severs clamped tissue.

[0038] The E-beam 178 can include upper pins 180 that engage the anvil 306 during firing. The E-beam 178 can further include middle pins 184 and a bottom foot 186 that can engage various portions of the cartridge body 194, cartridge tray 196, and elongated channel 302. When a surgical staple cartridge 304 is positioned within the elongated channel 302, a slot 193 defined in the cartridge body 194 can be aligned with a longitudinal slot 197 defined in the cartridge tray 196 and a slot 189 defined in the elongated channel 302. In use, the E-beam 178 can slide through the aligned longitudinal slots 193, 197, and 189 wherein, as indicated in FIG. 3, the bottom foot 186 of the E-beam 178 can engage a groove running along the bottom surface of elongated channel 302 along the length of slot 189, the middle pins 184 can engage the top surfaces of cartridge tray 196 along the length of longitudinal slot 197, and the upper pins 180 can engage the anvil 306. In such circumstances, the E-beam 178 can space, or limit the relative movement between, the anvil 306 and the surgical staple cartridge 304 as the firing bar 172 is moved distally to fire the staples from the surgical staple cartridge 304 and/or incise the tissue captured between the anvil 306 and the surgical staple cartridge 304. Thereafter, the firing bar 172 and the E-beam 178 can be retracted proximally allowing the anvil 306 to be opened to release the two stapled and severed tissue portions.

[0039] Referring to FIG. 4, in at least one arrangement, an interchangeable shaft assembly can be used in connection with an RF cartridge 1700 as well as a surgical staple/fastener cartridge.

[0040] The RF surgical cartridge 1700 includes a cartridge body 1710 that is sized and shaped to be removably received and supported in the elongate channel 1602. For example, the cartridge body 1710 may be configured to be removable retained in snap engagement with the elongate channel 1602. In at least one aspect, the cartridge body 1710 includes a centrally disposed elongate slot 1712 that extends longitudinally through the cartridge body to

accommodate longitudinal travel of a knife therethrough.

[0041] The cartridge body 1710 is formed with a centrally disposed raised electrode pad 1720. The elongate slot 1712 extends through the center of the electrode pad 1720 and serves to divide the pad 1720 into a left pad segment 1720L and a right pad segment 1720R. A right flexible circuit assembly 1730R is attached to the right pad segment 1720R and a left flexible circuit assembly 1730L is attached to the left pad segment 1720L. In at least one arrangement for example, the right flexible circuit 1730R comprises a plurality of wires 1732R that may include, for example, wider wires/conductors for RF purposes and thinner wires for conventional stapling purposes that are supported or attached or embedded into a right insulator sheath/member 1734R that is attached to the right pad 1720R. In addition, the right flexible circuit assembly 1730R includes a "phase one", proximal right electrode 1736R and a "phase two" distal right electrode 1738R. Likewise, the left flexible circuit assembly 1730L comprises a plurality of wires 1732L that may include, for example, wider wires/conductors for RF purposes and thinner wires for conventional stapling purposes that are supported or attached or embedded into a left insulator sheath/member 1734L that is attached to the left pad 1720L. In addition, the left flexible circuit assembly 1730L includes a "phase one", proximal left electrode 1736L and a "phase two" distal left electrode 1738L. The left and right wires 1732L, 1732R are attached to a distal micro-chip 1740 mounted to the distal end portion of the cartridge body 1710.

[0042] The elongate channel 1602 includes a channel circuit 1670 that is supported in a recess 1621 that extends from the proximal end of the elongate channel 1602 to a distal location 1623 in the elongate channel bottom portion 1620. The channel circuit 1670 includes a proximal contact portion 1672 that contacts a distal contact portion 1 169 of a flexible shaft circuit strip for electrical contact therewith. A distal end 1674 of the channel circuit 1670 is received within a corresponding wall recess 1625 formed in one of the channel walls 1622 and is folded over and attached to an upper edge 1627 of the channel wall 1622. A serial of corresponding exposed contacts 1676 are provided in the distal end 1674 of the channel circuit 1670. An end of a flexible cartridge circuit 1750 is attached to the distal micro-chip 1740 and is affixed to the distal end portion of the cartridge body 1710. Another end is folded over the edge of the cartridge deck surface 171 1 and includes exposed contacts configured to make electrical contact with the exposed contacts 1676 of the channel circuit 1670. Thus, when the RF cartridge 1700 is installed in the elongate channel 1602, the electrodes as well as the distal micro-chip 1740 are powered and communicate with an onboard circuit board through contact between the flexible cartridge circuit 1750, the flexible channel circuit 1670, a flexible shaft circuit and slip ring assembly.

[0043] FIG. 5 is another exploded assembly view of portions of the interchangeable shaft assembly 200 according to one aspect of this disclosure. The interchangeable shaft assembly 200 includes a firing member 220 that is supported for axial travel within a shaft spine 210. The firing member 220 includes an intermediate firing shaft portion 222 that is configured for attachment to a distal portion or bar 280. The intermediate firing shaft portion 222 may include a longitudinal slot 223 in the distal end thereof which can be configured to receive a tab 284 on the proximal end 282 of the distal bar 280. The longitudinal slot 223 and the proximal end 282 can be sized and configured to permit relative movement therebetween and can comprise a slip joint 286. The slip joint 286 can permit the intermediate firing shaft portion 222 of the firing member 220 to be moved to articulate the end effector 300 without moving, or at least substantially moving, the bar 280. Once the end effector 300 has been suitably oriented, the intermediate firing shaft portion 222 can be advanced distally until a proximal sidewall of the longitudinal slot 223 comes into contact with the tab 284 in order to advance the distal bar 280. Advancement of the distal bar 280 causes the E-beam 178 to be advanced distally to fire the staple cartridge positioned within the channel 302.

[0044] Further to the above, the shaft assembly 200 includes a clutch assembly 400 which can be configured to selectively and releasably couple the articulation driver 230 to the firing member 220. In one form, the clutch assembly 400 includes a lock collar, or sleeve 402, positioned around the firing member 220 wherein the lock sleeve 402 can be rotated between an engaged position in which the lock sleeve 402 couples the articulation drive 230 to the firing member 220 and a disengaged position in which the articulation drive 230 is not operably coupled to the firing member 220. When lock sleeve 402 is in its engaged position, distal movement of the firing member 220 can move the articulation drive 230 distally and, correspondingly, proximal movement of the firing member 220 can move the articulation drive 230 proximally. When lock sleeve 402 is in its disengaged position, movement of the firing member 220 is not transmitted to the articulation drive 230 and, as a result, the firing member 220 can move independently of the articulation drive 230.

[0045] The lock sleeve 402 can comprise a cylindrical, or an at least substantially cylindrical, body including a longitudinal aperture 403 defined therein configured to receive the firing member 220. The lock sleeve 402 can comprise diametrically-opposed, inwardly-facing lock protrusions 404 and an outwardly-facing lock member 406. The lock protrusions 404 can be configured to be selectively engaged with the firing member 220. More particularly, when the lock sleeve 402 is in its engaged position, the lock protrusions 404 are positioned within a drive notch 224 defined in the firing member 220 such that a distal pushing force and/or a proximal pulling force can be transmitted from the firing member 220 to the lock sleeve 402. When the lock sleeve 402 is in its engaged position, the second lock member 406 is received within a drive notch 232 defined in the articulation driver 230 such that the distal pushing force and/or the proximal pulling force applied to the lock sleeve 402 can be transmitted to the articulation driver 230. In effect, the firing member 220, the lock sleeve 402, and the articulation driver 230 will move together when the lock sleeve 402 is in its engaged position. On the other hand, when the lock sleeve 402 is in its disengaged position, the lock protrusions 404 may not be positioned within the drive notch 224 of the firing member 220 and, as a result, a distal pushing force and/or a proximal pulling force may not be transmitted from the firing member 220 to the lock sleeve 402. Correspondingly, the distal pushing force and/or the proximal pulling force may not be transmitted to the articulation driver 230. In such circumstances, the firing member 220 can be slid proximally and/or distally relative to the lock sleeve 402 and the proximal articulation driver 230.

[0046] The shaft assembly 200 further includes a switch drum 500 that is rotatably received on the closure tube 260. The switch drum 500 comprises a hollow shaft segment 502 that has a shaft boss 504 formed thereon for receive an outwardly protruding actuation pin 410 therein. In various circumstances, the actuation pin 410 extends through a slot 267 into a longitudinal slot 408 provided in the lock sleeve 402 to facilitate axial movement of the lock sleeve 402 when it is engaged with the articulation driver 230. A rotary torsion spring 420 is configured to engage the boss 504 on the switch drum 500 and a portion of the nozzle housing 203 as shown in FIG. 5 to apply a biasing force to the switch drum 500. The switch drum 500 can further comprise at least partially circumferential openings 506 defined therein which, referring to FIGS. 5 and 6, can be configured to receive circumferential mounts extending from the nozzle halves 202, 203 and permit relative rotation, but not translation, between the switch drum 500 and the proximal nozzle 201 . The mounts also extend through openings 266 in the closure tube 260 to be seated in recesses 21 1 in the shaft spine 210. However, rotation of the nozzle 201 to a point where the mounts reach the end of their respective openings 506 in the switch drum 500 will result in rotation of the switch drum 500 about the shaft axis SA-SA. Rotation of the switch drum 500 will ultimately result in the rotation of the actuation pin 410 and the lock sleeve 402 between its engaged and disengaged positions. Thus, in essence, the nozzle 201 may be employed to operably engage and disengage the articulation drive system with the firing drive system in the various manners described in further detail in U.S. Patent Application Serial No. 13/803,086.

[0047] The shaft assembly 200 can comprise a slip ring assembly 600 which can be configured to conduct electrical power to and/or from the end effector 300 and/or communicate signals to and/or from the end effector 300, for example. The slip ring assembly 600 can comprise a proximal connector flange 604 mounted to a chassis flange 242 extending from the chassis 240 and a distal connector flange 601 positioned within a slot defined in the nozzle halves 202, 203. The proximal connector flange 604 can comprise a first face and the distal connector flange 601 can comprise a second face which is positioned adjacent to and movable relative to the first face. The distal connector flange 601 can rotate relative to the proximal connector flange 604 about the shaft axis SA-SA. The proximal connector flange 604 can comprise a plurality of concentric, or at least substantially concentric, conductors 602 defined in the first face thereof. A connector 607 can be mounted on the proximal side of the connector flange 601 and may have a plurality of contacts, wherein each contact corresponds to and is in electrical contact with one of the conductors 602. Such an arrangement permits relative rotation between the proximal connector flange 604 and the distal connector flange 601 while maintaining electrical contact therebetween. The proximal connector flange 604 can include an electrical connector 606 which can place the conductors 602 in signal communication with a circuit board mounted to the shaft chassis 240, for example. In at least one instance, a wiring harness comprising a plurality of conductors can extend between the electrical connector 606 and the circuit board. U.S. Patent Application Serial No. 13/800,067, entitled STAPLE

CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on March 13, 2013, is

incorporated by reference in its entirety. U.S. Patent Application Serial No. 13/800,025, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on March 13, 2013, is incorporated by reference in its entirety. Further details regarding slip ring assembly 600 may be found in U.S. Patent Application Serial No. 13/803,086.

[0048] The shaft assembly 200 can include a proximal portion which is fixably mounted to the handle assembly 14 and a distal portion which is rotatable about a longitudinal axis. The rotatable distal shaft portion can be rotated relative to the proximal portion about the slip ring assembly 600. The distal connector flange 601 of the slip ring assembly 600 can be positioned within the rotatable distal shaft portion. Moreover, further to the above, the switch drum 500 can also be positioned within the rotatable distal shaft portion. When the rotatable distal shaft portion is rotated, the distal connector flange 601 and the switch drum 500 can be rotated

synchronously with one another. In addition, the switch drum 500 can be rotated between a first position and a second position relative to the distal connector flange 601 . When the switch drum 500 is in its first position, the articulation drive system may be operably disengaged from the firing drive system and, thus, the operation of the firing drive system may not articulate the end effector 300 of the shaft assembly 200. When the switch drum 500 is in its second position, the articulation drive system may be operably engaged with the firing drive system and, thus, the operation of the firing drive system may articulate the end effector 300 of the shaft assembly 200. When the switch drum 500 is moved between its first position and its second position, the switch drum 500 is moved relative to distal connector flange 601 .

[0049] In various examples, the shaft assembly 200 can comprise at least one sensor configured to detect the position of the switch drum 500. The distal connector flange 601 can comprise a Hall effect sensor 605, for example, and the switch drum 500 can comprise a magnetic element, such as permanent magnet 505, for example. The Hall effect sensor 605 can be configured to detect the position of the permanent magnet 505. When the switch drum 500 is rotated between its first position and its second position, the permanent magnet 505 can move relative to the Hall effect sensor 605. In various examples, Hall effect sensor 605 can detect changes in a magnetic field created when the permanent magnet 505 is moved. The Hall effect sensor 605 can be in signal communication with a control circuit, for example. Based on the signal from the Hall effect sensor 605, a microcontroller on the control circuit can determine whether the articulation drive system is engaged with or disengaged from the firing drive system.

[0050] A surgical instrument may not be able to use a rotatable shaft assembly effectively by using general wires to communicate power and signals between a fixed shaft portion and a rotatable shaft portion of the shaft assembly because the wires may get twisted or even damaged due to the repeated rotation of the shaft assembly. One way to overcome this deficiency may be to use a ring assembly instead of wires to communicate power and signals to the rotatable shaft portion. For example, a first flange with electrodes may be attached to the fixed shaft portion and a second flange with electrodes may rotate relative to the electrodes of the first flange. A gap is necessarily formed between the first flange and the second flange to permit the rotation of the second flange relative to the first flange. In order to maintain an electrical connection during the rotation of the rotatable shaft portion, the electrodes of the first and second flanges may be exposed at an interface therebetween. The gap may permit water and/or other body fluids ingress into the area between the first and second flanges where the electrode interface resides. Accordingly, the electrode interface may become exposed to water and other body fluids during surgery. Upon touching the exposed electrodes, the water and/or body fluids may cause signal noise or even loss of power/signals.

[0051] Aspects of the present disclosure improve slip ring assemblies in surgical instruments that that are exposed to water and/or body fluids during their operation. Aspects of the present disclosure may prevent signal noise and loss of power and signals by providing an insulative barrier to prevent water or fluids from reaching the electrodes.

[0052] Referring to FIG. 10, a slip ring assembly 1300 is illustrated. The slip ring assembly 1300 is similar in many respects to the slip ring assembly 600. For example, the slip ring assembly 1300 can be configured to conduct electrical power to and/or from the surgical end effector 300 and/or communicate signals to and/or from the surgical end effector 300, back to a circuit board 1301 , while facilitating rotational travel of a distal shaft portion of a shaft assembly relative to a proximal shaft portion of the shaft assembly. A shaft assembly 200 can be equipped with the slip ring assembly 1300 in lieu of the slip ring assembly 600, for example. In various examples a Zero Insertion Force (ZIF) connector 1316 can be coupled to the distal housing portion 1304 to transmit electrical signals and/or power to the end effector 300.

[0053] The slip ring assembly 1300 includes a housing 1302 comprising a proximal housing portion 1303 and a distal housing portion 1304. The housing 1302 can be incorporated into the shaft assembly 200. For example, the proximal housing portion 1303 can be fixed or attached to a proximal shaft portion of the shaft assembly 200. In one arrangement, the proximal housing portion 1303 can be mounted to the chassis flange 242 (FIG. 8) in the proximal shaft portion of the shaft assembly 200.

[0054] The distal housing portion 1304 can be fixed or attached to a distal shaft portion of the shaft assembly 200. In a user-controlled rotation of the shaft assembly 200, the distal shaft portion is rotated relative to the proximal shaft portion. The rotation of the distal shaft assembly causes the distal housing portion 1304 to rotate relative to the proximal housing portion 1303.

[0055] In an assembled configuration of the slip ring assembly 1300, as illustrated in FIG. 1 1 , the housing 1302 comprises a doughnut shape or a cylindrical shape that includes a central opening 1319 configured to receive the closure tube 260. The central opening 1319 is defined by inner perimeter walls 1309, 1310 of the proximal and distal housing portions 1303, 1304. In addition, an annular space 1321 (FIG. 13) is defined between the inner perimeter walls 1309, 1310 and outer perimeter walls 131 1 , 1312 of the proximal and distal housing portions 1303, 1304. An interface 1322 (FIG. 13) between the inner perimeter walls 1309, 1310 prevents, or at least resists, ingress of water and/or other body fluids into the annular space 1321 . An interface 1323 (FIG. 13) between the outer perimeter walls 131 1 , 1312 prevents, or at least resists, ingress of water and/or other body fluids into the annular space 1321.

[0056] The interfaces 1322, 1323 form a watertight barrier between the proximal housing portion 1303 and the distal housing portion 1304. Said another way, the interfaces 1322, 1323 are configured to effect a seal between the proximal housing portion 1303 and the distal housing portion 1304. In some examples, the interface 1322 includes an inner seal 1324 disposed between the inner perimeter walls 1309, 1310. In some examples, as illustrated in FIG. 12, the inner perimeter walls 1309, 1310 include opposing recesses or grooves 1329, 1330 configured to accommodate the inner seal 1324 therebetween. The grooves 1329, 1330 are sized and shaped to maintain a proper alignment of the seal 1324 with the proximal and distal housing portions 1303, 1304 as the distal housing portion 1304 is rotated relative to the proximal housing portion 1303. The groves 1329, 1330 cooperate with the seal 1324 to prevent, or at least resist, ingress of water and/or other body fluids into the annular space 1321 between the proximal and distal housing portions 1303, 1304.

[0057] In some examples, the interface 1323 includes an outer seal 1325 disposed between the outer perimeter walls 131 1 , 1312. In some examples, as illustrated in FIG. 12, the outer perimeter walls 131 1 , 1312 include opposing recesses or grooves 1331 , 1332 configured to accommodate the outer seal 1325 therebetween. The grooves 1331 , 1332 are sized and shaped to maintain a proper alignment of the seal 1325 with the proximal and distal housing portions 1303, 1304 as the distal housing portion 1304 is rotated relative to the proximal housing portion 1303. The groves 1331 , 1332 cooperate with the seal 1325 to prevent, or at least resist, ingress of water and/or other body fluids into the annular space 1321 between the proximal and distal housing portions 1303, 1304.

[0058] The inner seal 1324 can be attached to one of the inner perimeter walls 1309, 1310. In some examples, force fitting and/or an adhesive 1341 (FIG. 14) can be employed in the attachment of the inner seal 1324 to one of the inner perimeter walls 1309, 1310. In the example of FIG. 12, the inner seal 1324 is attached to the groove 1329 of the proximal housing portion 1303. The distal housing portion 1304 is rotatable relative to the inner seal 1324.

[0059] The outer seal 1325 can be attached to one of the outer perimeter walls 131 1 , 1312. In some examples, force fitting and/or an adhesive 1341 (FIG. 14) can be employed in the attachment of the outer seal 1325 to one of the outer perimeter walls 131 1 , 1312. In the example of FIG. 12, the outer seal 1325 is attached to the groove 1331 of the proximal housing portion 1303.

[0060] The distal housing portion 1304 is rotatable relative to the seals 1324, 1325. The grooves 1330, 1332 of the distal housing portion 1304 may comprise smooth contact surfaces to ensure maintaining an intimate contact with the seals 1324, 1325, respectively, as the grooves 1330, 1332 are rotated with the distal housing portion 1304 relative to the seals 1324, 1325. Such intimate contact between the grooves 1330, 1332 and the seals 1324, 1325 improves the resistance of the interfaces 1322, 1323 to ingress of water and/or other body fluids into the annular space 1321 of the housing 1302.

[0061] In some examples, the seals 1324, 1325 are compressible between the proximal housing portion 1303 and the distal housing portion 1304. In some examples, the seals 1324, 1325 can be made from a resilient elastomeric material such as platinum cured silicone rubber or polyurethane. In some examples, one or both of the seals 1324, 1325 comprise an annular shape and/or a circular cross-section. In some examples, one or both of the seals 1324, 1325 can be comprised from a biocompatible material. In some examples, one or both of the seals 1324, 1325 are O-rings.

[0062] In some examples, an interface between the proximal housing portion 1303 and the distal housing portion 1304 may comprise opposing flat surfaces and a seal between the flat surfaces that is attached to one of the flat surfaces. In some examples, an interface between the proximal housing portion 1303 and the distal housing portion 1304 may comprise different opposing surfaces and a seal between the different opposing surfaces that is attached to one of the different opposing surfaces. For example, one of the different opposing surfaces can be a flat surface while the other can be an arcuate surface defining a recess or a groove.

[0063] Referring to FIG. 10, the slip ring assembly 1300 includes a slip ring or proximal connector 1305 supported or held by the proximal housing portion 1303. As illustrated in FIG. 10, the proximal connector 1305 can be embedded into an annular socket defined between an inner perimeter wall 1309 and an outer perimeter wall 131 1 of the proximal housing portion 1303. In some examples, the proximal connector 1305 is attached to the proximal housing portion 1303 in an interference fit (e.g., a press fit, shrink fit or expansion fit). Other suitable attachment mechanisms can be employed, alone or in combination, to attach the proximal connector 1305 to the proximal housing portion 1303 such as, for example, a transition fit, a clearance fit, welding (e.g. laser welding), and/or adhesives.

[0064] The slip ring assembly 1300 also includes a commutator or distal connector 1306 supported or held by the distal housing portion 1304. The distal connector 1306 is attached to a distal wall 1318 of the distal housing portion 1306, and is embedded between an inner perimeter wall 1310 and an outer perimeter wall 1312 of the distal housing portion 1304.

[0065] The proximal connector 1305, as illustrated in FIG. 10, can be in the form of a slip ring that includes concentric and radially disposed conductors 1307 that are spaced apart from one another. The conductors 1307 comprise annular or hollow disk-shaped profiles that are concentric about a longitudinal axis 1320. The conductors 1307 in FIG. 10 have continuous or uninterrupted profiles. In other examples, one or more of the conductors 1307 may have an interrupted profile. In various examples, as illustrated in FIG. 10, the conductors 1307 are mounted on the proximal connector 1305 and are exposed, or at least partially exposed, within the annular space 1321 within the housing 1302.

[0066] When the slip ring assembly 1300 is assembled, conductors 1308 of the distal connector 1306 are configured to be in contact with corresponding conductors 1307 of the proximal connector 1305. In certain arrangements, the contact is maintained, or at least substantially maintained, while the distal connector 1306 and the conductors 1308 are rotated with the distal housing portion 1304 relative to the proximal connector 1305 and the conductors

1307 of proximal housing portion 1303.

[0067] The conductors 1308, as illustrated in FIG. 10, are mounted on the distal connector 1306, and are exposed, or at least partially exposed, within the annular space 1321 within the housing 1302. In various instances, the conductors 1308 can be in the form of resiliently biased pins, resiliently biased leaf springs, resiliently biased lever arms with end contacts, and/or any other spring contacts as will be apparent to one of ordinary skill in the art in view of the teachings herein. A conductor 1308 may include a silver graphite tip on the end of a beryllium copper leaf spring or a metallic gold alloy wire, for example. In the example of FIG. 10, the conductors 1308 are in the form of resiliently biased leaf springs.

[0068] In an assembled configuration of the slip ring assembly 1300, as illustrated in FIG. 13, a biasing member 1317 applies a load against the distal housing portion 1304. Since the proximal housing portion 1303 is fixed in position within the proximal shaft portion of the shaft assembly 200, the load causes the grooves 1330, 1332 of the distal housing portion 1304 to be pressed against the seals 1324, 1325, respectively, thereby effecting a seal between the proximal housing portion 1303 and the distal housing portion 1304.

[0069] In some examples, as illustrated in FIG. 12, the conductors 1308 protrude or extend a distance (d) beyond outside the distal housing portion 1304 in an unassembled configuration of the slip ring assembly 1300. However, in an assembled configuration, the conductors 1308 are biased by the proximal connector 1305 toward the distal housing portion 1304. The conductors

1308 are biased into a compressed state resulting in an increased contact pressure between the conductors 1308 and the conductors 1307 of the proximal connector 1305. The increase pressure improves signal and/or power transmission through the slip ring assembly 1300.

[0070] In various examples, a slip ring assembly 1300 includes conductors with different sizes configured to transmit different electrical signals. A larger size conductor, for example, may have a larger contact surface suitable for transmitting power through the slip ring assembly

1300. Examples of larger size conductors that are configured to transmit power through the slip ring assembly 1300 include conductors 1307a, in the proximal housing portion 1303, and conductors 1308a, in the distal housing portion 1304. In some examples, the conductors 1307a, 1308a are configured to transmit energy to an end effector that includes an RF cartridge 1700 (FIG. 4).

[0071] The slip ring assembly 1300 may also include smaller size conductors that may have smaller contact surfaces suitable for transmitting data signals through the slip ring assembly 1300. Examples of smaller size conductors that are configured to transmit data through the slip ring assembly 1300 include conductors 1307b, in the proximal housing portion 1303, and conductors 1308b, in the distal housing portion 1304.

[0072] A contact surface of a conductor can be defined as a surface of the conductor in physical contact with a contact surface of an opposing conductor. The larger the contact surfaces of two opposing conductors, the greater the energy that can be transmitted through them. Furthermore, the spacing between adjacent conductors with the larger contact surfaces is generally greater than the spacing between adjacent conductors with smaller contact surfaces.

[0073] Referring to FIG. 14, an exemplary proximal housing portion 1303 is depicted demonstrating an exemplary layout of the conductors 1307a, 1307b of a proximal connector 1305. A layout of the conductors 1308a, 1308b can be configured to mirror the layout depicted in FIG. 14 of the conductors 1307a, 1307b. In some examples, the conductors 1307a, 1308a are at least three times the size of the conductors 1307b, 1308b, respectively. In other examples, the conductors 1307a, 1308a are at least twice the size of the conductors 1307b, 1308b, respectively. In other examples, the conductors 1307a, 1308a are at least four times the size of the conductors 1307b, 1308b, respectively.

[0074] The conductors 1307a, 1308a comprise larger contact surfaces than the conductors 1307b, 1308b, respectively. In some examples, the contact surfaces of the conductors 1307a, 1308a are at least three times larger than the contact surfaces of the conductors 1307b, 1308b, respectively. In some examples, the contact surfaces of the conductors 1307a, 1308a are at least twice larger than the contact surfaces of the conductors 1307b, 1308b, respectively. In some examples, the contact surfaces of the conductors 1307a, 1308a are at least four times larger than the contact surfaces of the conductors 1307b, 1308b, respectively.

[0075] The conductors 1307a, 1308a comprise greater widths than the conductors 1307b, 1308b, respectively. In some examples, the widths of the conductors 1307a, 1308a are at least three times greater than the widths of the conductors 1307b, 1308b, respectively. In some examples, the widths of the conductors 1307a, 1308a are at least four times greater than the widths of the conductors 1307b, 1308b, respectively. In some examples, the widths of the conductors 1307a, 1308a are at least two times greater than the widths of the conductors 1307b, 1308b, respectively.

[0076] In some examples, the conductors 1307a, 1308a may comprise a width (W1) selected from a range of about 0.050" to about 0.100". In some examples, the conductors 1307a, 1308a may comprise a width (W1 ) selected from a range of about 0.060" to about 0.1090". In some examples, the conductors 1307a, 1308a may comprise a width (W1 ) of about 0.075". [0077] In contrast, in some examples, the conductors 1307b, 1308b may comprise a width (W2) selected from a range of about 0.005" to about 0.050". In some examples, the conductors 1307b, 1308b may comprise a width (W2) selected from a range of about 0.010" to about 0.030". In some examples, the conductors 1307b, 1308b may comprise a width (W2) of about 0.025".

[0078] In some examples, adjacent conductors 1307a are spaced apart a distance (d1 ) selected from a range of about 0.025" to about 0.075", and adjacent conductors 1308a are also spaced apart a distance selected from a range of about 0.025" to about 0.075". In some examples, adjacent conductors 1307a are spaced apart a distance (d1) of about 0.050", and adjacent conductors 1308a are also spaced apart a distance (d1 ) of about 0.050". Other values for the distance (d1 ) are contemplated by the present disclosure.

[0079] In contrast, in some examples, adjacent conductors 1307b are spaced apart a distance (d2) selected from a range of about 0.005" to about 0.025", and adjacent conductors 1308b are also spaced apart a distance (d2) selected from a range of about 0.005" to about 0.025". In some examples, adjacent conductors 1307b are spaced apart a distance (d2) of about 0.015", and adjacent conductors 1308b are also spaced apart a distance (d2) of about 0.015". Other values for the distance (d2) are contemplated by the present disclosure.

[0080] In some examples, adjacent conductors 1307a, 1307b are spaced apart a distance (d3) selected from a range of about 0.005" to about 0.025", and adjacent conductors 1308a, 1308b are also spaced apart a distance (d3) selected from a range of about 0.005" to about 0.025". In some example, a distance (d3) between a conductor 1307a and an adjacent conductor 1307b can be about 0.015", and a distance (d3) between a conductor 1308a and an adjacent conductor 1308b can also be about 0.015". Other values for the distance (d3) are contemplated by the present disclosure.

[0081] In some examples, one or more of the conductors of the slip ring assembly 1300 comprises a thickness (T1 ) that is about 0.050". In some examples, the thickness (T1 ) can be selected from a range of about 0.010" to about 0.100", for example. Other values for the thickness (T1 ) are contemplated by the present disclosure.

[0082] In various examples, one or more conductors of a slip ring assembly of the present disclosure are covered with an external coating that is configured to minimize signal noise and/or loss of power/signals that can be caused by exposure of the conductors to water and/or other bodily fluids. For example, conductors 1307 of a slip ring or proximal connector 1305 can be covered with a layer or coating that is less conductive than the conductors 1307. Said another way, the coating may be more resistive than the conductors 1307. [0083] In various examples, one or more of the conductors 1307 can be coated with a semi- conductive material including, for example, Carbon (C), Germanium (Ge), Silicon (S), Gallium arsenide (GaAs), and/or Silicon carbide (SiC) in order to reduce signal noise and/or loss of power/signals in water and/or other body fluids. In some examples, one or more of the conductors 1307 can be coated with a carbon ink or a silver ink. Alternatively, in other examples, the conductorsl 307 can be fully made from a carbon ink or a silver ink. Any suitable carbon ink or silver ink can be utilized to make or coat the conductorsl 307. In some examples, an ELECTRA DOR™ ED5500 series Carbon conductor paste can be utilized to make or coat the conductors in order to reduce signal noise and/or loss of power/signals in water and/or other body fluids. The ED5500 is a range of carbon and silver/carbon conductive pastes. They are designed for high reliability applications where protection of metal contacts is required.

Examples of other usable commercial conductive carbon ink include e.g. XZ302-1 HV and XZ302-1 MV conductive Carbon.

[0084] In various examples, one or more of the conductors 1307 can be coated, or otherwise covered, with an external coating or layer and an intermediate coating or layer closer to the conductors 1307 than the intermediate layer. The external layer can be less conductive than the intermediate layer. In at least one example, the external and intermediate layers can be comprised of non-conductive matrices that include conductive particles or fillers dispersed and/or embedded therein. In such examples, the density of the conductive particles in the intermediate layer is higher than the external layer. In result, the external layer possesses a higher resistivity than the intermediate layer which minimizes signal noise and/or loss of power/signals that can be caused by exposure of the conductors to water and/or other bodily fluids.

[0085] In various examples, one or more of the conductors 1307 are coated, or otherwise covered, with a compressible coating or layer. The compressible layer comprises a first conductivity in an uncompressed configuration and a second conductivity in a compressed configuration. In at least one example, the second conductivity is greater than the first conductivity. The first conductivity is sufficiently reduced to protect against any signal noise and/or loss of power/signals due to contact with water and/or other bodily fluid. In other words, the compressible layer or coating acts as a resistive layer or coating unless it is compressed. Once compressed, the compressible layer or coating becomes conductive to electricity only at the portion thereof that is compressed.

[0086] As illustrated in FIG. 13, the conductors 1308 are slightly biased when in contact with the conductors 1307. When a conductor 1307 comprises a compressible layer, the biasing force applied by the conductor 1308 may compress the compressible layer at a portion of the compressible layer in contact with the conductor 1308. The compression applied by the conductor 1308 may change the conductivity of the compressible layer at the compressed portion. In at least one example, the compression applied by the conductor 1308 may increase the conductivity of the compressible layer at the compressed portion. The conductivity of other portions of the compressible layer experiencing little or no compression may not change significantly.

[0087] As described above, the conductors 1308 are rotated with the commutator or distal connector 1306 relative to the proximal connector 1305 while contact is maintain, or at least substantially maintained, between the conductors 1307 and the conductors 1308 to transmit an electrical signal to and/or from the end effector 300. The rotation causes the conductors 1308 to transition from one compressed portion of the compressible layer to another, and the transmission of the electrical signal between the conductors 1307, 1308 is maintained at the compressed portions. The reduced conductivity of the uncompressed portions protects against any signal noise and/or loss of power/signals due to contact with water and/or other bodily fluid. Since the compressed portions are in direct contact with the conductors 1308, the compressed portions are also protected from the water and/or other bodily fluid.

[0088] Examples of compressible layers or coatings that experience a change in conductivity or resistivity under compression include various compressive carbon coatings. Other examples of suitable compressible layers or coatings include layers or coatings comprising polymer matrices with conductive fillers dispersed within the polymer matrices. Applying a localized compression to a portion of the polymer matrix causes the conductive fillers at the compressed portion to be brought closer to one another. The increased density of the conductive fillers increases the conductivity of the compressed portion. Other examples of suitable compressible layers or coatings include layers or coatings that are comprised, or at least partially comprised, of electroactive polymer and/or conductive polymer composites.

[0089] Although various devices have been described herein in connection with certain embodiments, modifications and variations to those embodiments may be implemented.

Particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined in whole or in part, with the features, structures or characteristics of one ore more other embodiments without limitation. Also, where materials are disclosed for certain components, other materials may be used. Furthermore, according to various embodiments, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to perform a given function or functions. The foregoing description and following claims are intended to cover all such modification and variations.

[0090] The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, a device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps including, but not limited to, the disassembly of the device, followed by cleaning or replacement of particular pieces of the device, and subsequent reassembly of the device. In particular, a reconditioning facility and/or surgical team can disassemble a device and, after cleaning and/or replacing particular parts of the device, the device can be reassembled for subsequent use. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.

[0091] The devices disclosed herein may be processed before surgery. First, a new or used instrument may be obtained and, when necessary, cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, and/or high-energy electrons. The radiation may kill bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a medical facility. A device may also be sterilized using any other technique known in the art, including but not limited to beta radiation, gamma radiation, ethylene oxide, plasma peroxide, and/or steam.

[0092] While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles.

[0093] Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials do 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.

[0094] Various aspects of the subject matter described herein are set out in the following numbered examples:

[0095] Example 1 - A slip ring assembly for use with a surgical shaft assembly, the slip ring assembly comprising a first housing portion, a first connector supported in the first housing portion, and a first conductor mounted on the first connector. The slip ring assembly further comprises a second housing portion, a second connector supported in the second housing portion, and a second conductor mounted on the second connector. The second housing portion is rotatable relative to the first housing portion. The second conductor is in contact with the first conductor. The slip ring assembly further comprises an interface between the first housing portion and the second housing portion, wherein the interface is configured to effect a seal between the first housing portion and the second housing portion.

[0096] Example 2 - The slip ring assembly of Example 1 , further comprising a resilient member configured to apply a load onto the second housing portion to maintain the seal.

[0097] Example 3 - The slip ring assembly of one or more of Example 1 through Example 2, wherein the resilient member is a spring coupled to the second housing portion.

[0098] Example 4 - The slip ring assembly of one or more of Example 1 through Example 3, further comprising a third conductor mounted on the first connector and a fourth conductor mounted on the second connector.

[0099] Example 5 - The slip ring assembly of one or more of Example 1 through Example 4, wherein the first conductor comprises a greater contact surface than the third conductor, and wherein the second conductor comprises a greater contact surface than the fourth conductor.

[0100] Example 6 - The slip ring assembly of one or more of Example 1 through Example 5, wherein the first conductor and the second conductor are configured to transmit a first electrical signal.

[0101] Example 7 - The slip ring assembly of one or more of Example 1 through Example 6, wherein the third conductor and the fourth conductor are configured to transmit a second electrical signal different than the first electrical signal.

[0102] Example 8 - The slip ring assembly of one or more of Example 1 through Example 7, wherein the interface comprises an O-ring mounted on the first housing portion and a recess in the second housing portion configured to receive the O-ring to form a watertight barrier between the first housing portion and the second housing portion. [0103] Example 9 - The slip ring assembly of one or more of Example 1 through Example 8, wherein the O-ring is compressible.

[0104] Example 10 - A shaft assembly for use with a surgical instrument, the shaft assembly comprising a housing and a slip ring assembly. The housing comprises a proximal housing portion and a distal housing portion rotatable relative to the proximal housing portion. The slip ring assembly comprises a proximal connector supported in the proximal housing portion, a plurality of first conductors mounted on the proximal connector, a distal connector supported in the distal housing portion, and a plurality of second conductors mounted on the distal connector. The second conductors are rotatable relative to the first conductors and are in contact therewith. The proximal housing portion and the distal housing portion are configured to resist water ingress into the housing.

[0105] Example 1 1 - The shaft assembly of Example 10, further comprising a resilient member configured to apply a load onto the distal housing portion.

[0106] Example 12 - The shaft assembly of one or more of Example 10 through Example 1 1 , wherein the resilient member is a spring coupled to the distal housing portion.

[0107] Example 13 - The shaft assembly of one or more of Example 10 through Example 12, wherein the first conductors comprise different sizes.

[0108] Example 14 - The shaft assembly of one or more of Example 10 through Example 13, wherein the second conductors comprise different sizes.

[0109] Example 15 - The shaft assembly of one or more of Example 10 through Example 14, further comprising a seal between the proximal housing portion and the distal housing portion.

[0110] Example 16 - The shaft assembly of one or more of Example 10 through Example 15, wherein the seal is compressible.

[0111] Example 17 - A slip ring assembly for use with a surgical shaft assembly, the slip ring assembly comprising a first housing portion, a slip ring supported in the first housing portion, and a first conductor mounted on the slip ring. The slip ring assembly further comprises a second housing portion, a commutator supported in the second housing portion, and a second conductor mounted on the commutator. The second conductor is rotatable relative to the first conductor and is in contact therewith. The first housing portion and the second housing portion are configured to form a watertight barrier around the first and second conductors.

[0112] Example 18 - The slip ring assembly of Example 17, further comprising a first seal between the first housing portion and the second housing portion. [0113] Example 19 - The slip ring assembly of one or more of Example 17 through Example

18, further comprising a second seal between the first housing portion and the second housing portion.

[0114] Example 20 - The slip ring assembly of one or more of Example 17 through Example

19, wherein the second seal is concentric with the first seal.

[0115] Example 21 - A slip ring assembly is used with a surgical instrument. The slip ring assembly comprises a first connector and first conductor mounted on the first connector. The slip ring assembly further comprises a second connector, wherein the first connector is rotatable relative to the second connector. The slip ring assembly further comprises second conductors mounted on the second connector, wherein the first conductors and the second conductors are configured to transmit an electrical signal therebetween, and wherein the second conductors comprise a coating configured to minimize an unintended change to the electrical signal.

[0116] Example 22 - The slip ring assembly of Example 21 , wherein the coating comprises a different resistive level than the second conductors.

[0117] Example 23 - The slip ring assembly of one or more of Example 21 through Example

22, wherein the coating is compressible.

[0118] Example 24 - The slip ring assembly of one or more of Example 21 through Example

23, wherein compressing a portion of the coating changes a resistive property of the coating at the compressed portion.

[0119] Example 25 - The slip ring assembly of one or more of Example 21 through Example 24 wherein the coating comprises an external layer, and an intermediate layer closer to the second conductors than the external layer, wherein the intermediate layer is more conductive than the external layer.

[0120] Example 26 - The slip ring assembly of one or more of Example 21 through Example 25, wherein the unintended change comprises a signal loss or noise.