Surgical instrument systems comprising an articulatable end effector and means for adjusting the firing stroke of a firing member

[0001] The present invention relates to surgical instruments and, in various embodiments, to surgical stapling and cutting instruments and staple cartridges for use therewith.

[0002] A stapling instrument can include a pair of cooperating elongate jaw members, wherein each jaw member can be adapted to be inserted into a patient and positioned relative to tissue that is to be stapled and/or incised. In various embodiments, one of the jaw members can support a staple cartridge with at least two laterally spaced rows of staples contained therein, and the other jaw member can support an anvil with staple-forming pockets aligned with the rows of staples in the staple cartridge. Generally, the stapling instrument can further include a pusher bar and a knife blade which are slidable relative to the jaw members to sequentially eject the staples from the staple cartridge via camming surfaces on the pusher bar and/or camming surfaces on a wedge sled that is pushed by the pusher bar. In at least one embodiment, the camming surfaces can be configured to activate a plurality of staple drivers carried by the cartridge and associated with the staples in order to push the staples against the anvil and form laterally spaced rows of deformed staples in the tissue gripped between the jaw members. In at least one embodiment, the knife blade can trail the camming surfaces and cut the tissue along a line between the staple rows. Examples of such stapling instruments are disclosed in U.S. Pat. No. 7,794,475, entitled SURGICAL STAPLES HAVING COMPRESSIBLE OR CRUSHABLE MEMBERS FOR SECURING TISSUE THEREIN AND STAPLING INSTRUMENTS FOR DEPLOYING THE SAME, the entire disclosure of which is hereby incorporated by reference herein.

[0003] The foregoing discussion is intended only to illustrate various aspects of the related art in the field of the invention at the time, and should not be taken as a disavowal of claim scope.

[0058] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate various embodiments of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

[0059] Applicant of the present application owns the following patent applications that were filed on Dec. 18, 2014, which are each herein incorporated by reference in their respective entireties:

• [0060] U.S. patent application Ser. No. 14/574,483, entitled SURGICAL INSTRUMENT ASSEMBLY COMPRISING LOCKABLE SYSTEMS; now U.S. Patent Application Publication No. 2016/0174969;
• [0061] U.S. patent application Ser. No. 14/575,139, entitled DRIVE ARRANGEMENTS FOR ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2016/0174978;
• [0062] U.S. patent application Ser. No. 14/575,148, entitled LOCKING ARRANGEMENTS FOR DETACHABLE SHAFT ASSEMBLIES WITH ARTICULATABLE SURGICAL END EFFECTORS, now U.S. Patent Application Publication No. 2016/0174976;
• [0063] U.S. patent application Ser. No. 14/575,130, entitled SURGICAL INSTRUMENT WITH AN ANVIL THAT IS SELECTIVELY MOVABLE ABOUT A DISCRETE NON-MOVABLE AXIS RELATIVE TO A STAPLE CARTRIDGE, now U.S. Patent Application Publication No. 2016/0174972;
• [0064] U.S. patent application Ser. No. 14/575,143, entitled SURGICAL INSTRUMENTS WITH IMPROVED CLOSURE ARRANGEMENTS; now U.S. Patent Application Publication No. 2016/0174983;
• [0065] U.S. patent application Ser. No. 14/575,117, entitled SURGICAL INSTRUMENTS WITH ARTICULATABLE END EFFECTORS AND MOVABLE FIRING BEAM SUPPORT ARRANGEMENTS, now U.S. Patent Application Publication No. 2016/0174975;
• [0066] U.S. patent application Ser. No. 14/575,154, entitled SURGICAL INSTRUMENTS WITH ARTICULATABLE END EFFECTORS AND IMPROVED FIRING BEAM SUPPORT ARRANGEMENTS, now U.S. Patent Application Publication No. 2016/0174973;
• [0067] U.S. patent application Ser. No. 14/574,493, entitled SURGICAL INSTRUMENT ASSEMBLY COMPRISING A FLEXIBLE ARTICULATION SYSTEM; now U.S. Patent Application Publication No. 2016/0174970; and
• [0068] U.S. patent application Ser. No. 14/574,500, entitled SURGICAL INSTRUMENT ASSEMBLY COMPRISING A LOCKABLE ARTICULATION SYSTEM; now U.S. Patent Application Publication No. 2016/0174971.

[0069] Applicant of the present application owns the following patent applications that were filed on Mar. 1, 2013 and which are each herein incorporated by reference in their respective entireties:

• [0070] U.S. patent application Ser. No. 13/782,295, entitled ARTICULATABLE SURGICAL INSTRUMENTS WITH CONDUCTIVE PATHWAYS FOR SIGNAL COMMUNICATION, now U.S. Patent Application Publication No. 2014/0246471;
• [0071] U.S. patent application Ser. No. 13/782,323, entitled ROTARY POWERED ARTICULATION JOINTS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0246472;
• [0072] U.S. patent application Ser. No. 13/782,338, entitled THUMBWHEEL SWITCH ARRANGEMENTS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0249557;
• [0073] U.S. patent application Ser. No. 13/782,499, entitled ELECTROMECHANICAL SURGICAL DEVICE WITH SIGNAL RELAY ARRANGEMENT, now U.S. Patent Application Publication No. 2014/0246474;
• [0074] U.S. patent application Ser. No. 13/782,460, entitled MULTIPLE PROCESSOR MOTOR CONTROL FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0246478;
• [0075] U.S. patent application Ser. No. 13/782,358, entitled JOYSTICK SWITCH ASSEMBLIES FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0246477;
• [0076] U.S. patent application Ser. No. 13/782,481, entitled SENSOR STRAIGHTENED END EFFECTOR DURING REMOVAL THROUGH TROCAR, now U.S. Patent Application Publication No. 2014/0246479;
• [0077] U.S. patent application Ser. No. 13/782,518, entitled CONTROL METHODS FOR SURGICAL INSTRUMENTS WITH REMOVABLE IMPLEMENT PORTIONS, now U.S. Patent Application Publication No. 2014/0246475;
• [0078] U.S. patent application Ser. No. 13/782,375, entitled ROTARY POWERED SURGICAL INSTRUMENTS WITH MULTIPLE DEGREES OF FREEDOM, now U.S. Patent Application Publication No. 2014/0246473; and
• [0079] U.S. patent application Ser. No. 13/782,536, entitled SURGICAL INSTRUMENT SOFT STOP, now U.S. Patent Application Publication No. 2014/0246476.

[0080] Applicant of the present application also owns the following patent applications that were filed on Mar. 14, 2013 and which are each herein incorporated by reference in their respective entireties:

• [0081] U.S. patent application Ser. No. 13/803,097, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, now U.S. Patent Application Publication No. 2014/0263542;
• [0082] U.S. patent application Ser. No. 13/803,193, entitled CONTROL ARRANGEMENTS FOR A DRIVE MEMBER OF A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0263537;
• [0083] U.S. patent application Ser. No. 13/803,053, entitled INTERCHANGEABLE SHAFT ASSEMBLIES FOR USE WITH A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0263564;
• [0084] U.S. patent application Ser. No. 13/803,086, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, now U.S. Patent Application Publication No. 2014/0263541;
• [0085] U.S. patent application Ser. No. 13/803,210, entitled SENSOR ARRANGEMENTS FOR ABSOLUTE POSITIONING SYSTEM FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0263538;
• [0086] U.S. patent application Ser. No. 13/803,148, entitled MULTI-FUNCTION MOTOR FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0263554;
• [0087] U.S. patent application Ser. No. 13/803,066, entitled DRIVE SYSTEM LOCKOUT ARRANGEMENTS FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0263565;
• [0088] U.S. patent application Ser. No. 13/803,117, entitled ARTICULATION CONTROL SYSTEM FOR ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0263553;
• [0089] U.S. patent application Ser. No. 13/803,130, entitled DRIVE TRAIN CONTROL ARRANGEMENTS FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0263543; and
• [0090] U.S. patent application Ser. No. 13/803,159, entitled METHOD AND SYSTEM FOR OPERATING A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0277017.

[0091] Applicant of the present application also owns the following patent application that was filed on Mar. 7, 2014 and is herein incorporated by reference in its entirety:

• [0092] U.S. patent application Ser. No. 14/200,111, entitled CONTROL SYSTEMS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0263539.

[0093] Applicant of the present application also owns the following patent applications that were filed on Mar. 26, 2014 and are each herein incorporated by reference in their respective entireties:

• [0094] U.S. patent application Ser. No. 14/226,106, entitled POWER MANAGEMENT CONTROL SYSTEMS FOR SURGICAL INSTRUMENTS;
• [0095] U.S. patent application Ser. No. 14/226,099, entitled STERILIZATION VERIFICATION CIRCUIT;
• [0096] U.S. patent application Ser. No. 14/226,094, entitled VERIFICATION OF NUMBER OF BATTERY EXCHANGES/PROCEDURE COUNT;
• [0097] U.S. patent application Ser. No. 14/226,117, entitled POWER MANAGEMENT THROUGH SLEEP OPTIONS OF SEGMENTED CIRCUIT AND WAKE UP CONTROL;
• [0098] U.S. patent application Ser. No. 14/226,075, entitled MODULAR POWERED SURGICAL INSTRUMENT WITH DETACHABLE SHAFT ASSEMBLIES;
• [0099] U.S. patent application Ser. No. 14/226,093, entitled FEEDBACK ALGORITHMS FOR MANUAL BAILOUT SYSTEMS FOR SURGICAL INSTRUMENTS;
• [0100] U.S. patent application Ser. No. 14/226,116, entitled SURGICAL INSTRUMENT UTILIZING SENSOR ADAPTATION;
• [0101] U.S. patent application Ser. No. 14/226,071, entitled SURGICAL INSTRUMENT CONTROL CIRCUIT HAVING A SAFETY PROCESSOR;
• [0102] U.S. patent application Ser. No. 14/226,097, entitled SURGICAL INSTRUMENT COMPRISING INTERACTIVE SYSTEMS;
• [0103] U.S. patent application Ser. No. 14/226,126, entitled INTERFACE SYSTEMS FOR USE WITH SURGICAL INSTRUMENTS;
• [0104] U.S. patent application Ser. No. 14/226,133, entitled MODULAR SURGICAL INSTRUMENT SYSTEM;
• [0105] U.S. patent application Ser. No. 14/226,081, entitled SYSTEMS AND METHODS FOR CONTROLLING A SEGMENTED CIRCUIT;
• [0106] U.S. patent application Ser. No. 14/226,076, entitled POWER MANAGEMENT THROUGH SEGMENTED CIRCUIT AND VARIABLE VOLTAGE PROTECTION;
• [0107] U.S. patent application Ser. No. 14/226,111, entitled SURGICAL STAPLING INSTRUMENT SYSTEM; and
• [0108] U.S. patent application Ser. No. 14/226,125, entitled SURGICAL INSTRUMENT COMPRISING A ROTATABLE SHAFT.

[0109] Applicant of the present application also owns the following patent applications that were filed on Sep. 5, 2014 and which are each herein incorporated by reference in their respective entireties:

• [0110] U.S. patent application Ser. No. 14/479,103, entitled CIRCUITRY AND SENSORS FOR POWERED MEDICAL DEVICE;
• [0111] U.S. patent application Ser. No. 14/479,119, entitled ADJUNCT WITH INTEGRATED SENSORS TO QUANTIFY TISSUE COMPRESSION;
• [0112] U.S. patent application Ser. No. 14/478,908, entitled MONITORING DEVICE DEGRADATION BASED ON COMPONENT EVALUATION;
• [0113] U.S. patent application Ser. No. 14/478,895, entitled MULTIPLE SENSORS WITH ONE SENSOR AFFECTING A SECOND SENSOR'S OUTPUT OR INTERPRETATION;
• [0114] U.S. patent application Ser. No. 14/479,110, entitled USE OF POLARITY OF HALL MAGNET DETECTION TO DETECT MISLOADED CARTRIDGE;
• [0115] U.S. patent application Ser. No. 14/479,098, entitled SMART CARTRIDGE WAKE UP OPERATION AND DATA RETENTION;
• [0116] U.S. patent application Ser. No. 14/479,115, entitled MULTIPLE MOTOR CONTROL FOR POWERED MEDICAL DEVICE; and
• [0117] U.S. patent application Ser. No. 14/479,108, entitled LOCAL DISPLAY OF TISSUE PARAMETER STABILIZATION.

[0118] Applicant of the present application also owns the following patent applications that were filed on Apr. 9, 2014 and which are each herein incorporated by reference in their respective entireties:

• [0119] U.S. patent application Ser. No. 14/248,590, entitled MOTOR DRIVEN SURGICAL INSTRUMENTS WITH LOCKABLE DUAL DRIVE SHAFTS, now U.S.

[0120] Patent Application Publication No. 2014/0305987;

• [0121] U.S. patent application Ser. No. 14/248,581, entitled SURGICAL INSTRUMENT COMPRISING A CLOSING DRIVE AND A FIRING DRIVE OPERATED FROM THE SAME ROTATABLE OUTPUT, now U.S. Patent Application Publication No. 2014/0305989;
• [0122] U.S. patent application Ser. No. 14/248,595, entitled SURGICAL INSTRUMENT SHAFT INCLUDING SWITCHES FOR CONTROLLING THE OPERATION OF THE SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0305988;
• [0123] U.S. patent application Ser. No. 14/248,588, entitled POWERED LINEAR SURGICAL STAPLER, now U.S. Patent Application Publication No. 2014/0309666;
• [0124] U.S. patent application Ser. No. 14/248,591, entitled TRANSMISSION ARRANGEMENT FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0305991;
• [0125] U.S. patent application Ser. No. 14/248,584, entitled MODULAR MOTOR DRIVEN SURGICAL INSTRUMENTS WITH ALIGNMENT FEATURES FOR ALIGNING ROTARY DRIVE SHAFTS WITH SURGICAL END EFFECTOR SHAFTS, now U.S. Patent Application Publication No. 2014/0305994;
• [0126] U.S. patent application Ser. No. 14/248,587, entitled POWERED SURGICAL STAPLER, now U.S. Patent Application Publication No. 2014/0309665;
• [0127] U.S. patent application Ser. No. 14/248,586, entitled DRIVE SYSTEM DECOUPLING ARRANGEMENT FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0305990; and
• [0128] U.S. patent application Ser. No. 14/248,607, entitled MODULAR MOTOR DRIVEN SURGICAL INSTRUMENTS WITH STATUS INDICATION ARRANGEMENTS, now U.S. Patent Application Publication No. 2014/0305992.

[0129] Applicant of the present application also owns the following patent applications that were filed on Apr. 16, 2013 and which are each herein incorporated by reference in their respective entireties:

• [0130] U.S. Provisional Patent Application Ser. No. 61/812,365, entitled SURGICAL INSTRUMENT WITH MULTIPLE FUNCTIONS PERFORMED BY A SINGLE MOTOR;
• [0131] U.S. Provisional Patent Application Ser. No. 61/812,376, entitled LINEAR CUTTER WITH POWER;
• [0132] U.S. Provisional Patent Application Ser. No. 61/812,382, entitled LINEAR CUTTER WITH MOTOR AND PISTOL GRIP;
• [0133] U.S. Provisional Patent Application Ser. No. 61/812,385, entitled SURGICAL INSTRUMENT HANDLE WITH MULTIPLE ACTUATION MOTORS AND MOTOR CONTROL; and
• [0134] U.S. Provisional Patent Application Ser. No. 61/812,372, entitled SURGICAL INSTRUMENT WITH MULTIPLE FUNCTIONS PERFORMED BY A SINGLE MOTOR.

[0135] Numerous specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the accompanying drawings. Well-known operations, components, and elements have not been described in detail so as not to obscure the embodiments described in the specification. The reader will understand that the embodiments described and illustrated herein are non-limiting examples, and thus it can be appreciated that the specific structural and functional details disclosed herein may be representative and illustrative. Variations and changes thereto may be made without departing from the scope of the claims.

[0136] 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.

[0137] The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” referring to the portion closest to the clinician and the term “distal” referring to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical”, “horizontal”, “up”, and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute.

[0138] Various exemplary devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. However, the reader will readily appreciate that the various methods and devices disclosed herein can be used in numerous surgical procedures and applications including, for example, in connection with open surgical procedures. As the present Detailed Description proceeds, the reader will further appreciate that the various instruments disclosed herein can be inserted into a body in any way, such as through a natural orifice, through an incision or puncture hole formed in tissue, etc. The working portions or end effector portions of the instruments can be inserted directly into a patient's body or can be inserted through an access device that has a working channel through which the end effector and elongated shaft of a surgical instrument can be advanced.

[0139] A surgical stapling system can comprise a shaft and an end effector extending from the shaft. The end effector comprises a first jaw and a second jaw. The first jaw comprises a staple cartridge. The staple cartridge is insertable into and removable from the first jaw; however, other embodiments are envisioned in which a staple cartridge is not removable from, or at least readily replaceable from, the first jaw. The second jaw comprises an anvil configured to deform staples ejected from the staple cartridge. The second jaw is pivotable relative to the first jaw about a closure axis; however, other embodiments are envisioned in which first jaw is pivotable relative to the second jaw. The surgical stapling system further comprises an articulation joint configured to permit the end effector to be rotated, or articulated, relative to the shaft. The end effector is rotatable about an articulation axis extending through the articulation joint. Other embodiments are envisioned which do not include an articulation joint.

[0140] The staple cartridge comprises a cartridge body. The cartridge body includes a proximal end, a distal end, and a deck extending between the proximal end and the distal end. In use, the staple cartridge is positioned on a first side of the tissue to be stapled and the anvil is positioned on a second side of the tissue. The anvil is moved toward the staple cartridge to compress and clamp the tissue against the deck. Thereafter, staples removably stored in the cartridge body can be deployed into the tissue. The cartridge body includes staple cavities defined therein wherein staples are removably stored in the staple cavities. The staple cavities are arranged in six longitudinal rows. Three rows of staple cavities are positioned on a first side of a longitudinal slot and three rows of staple cavities are positioned on a second side of the longitudinal slot. Other arrangements of staple cavities and staples may be possible.

[0141] The staples are supported by staple drivers in the cartridge body. The drivers are movable between a first, or unfired position, and a second, or fired, position to eject the staples from the staple cavities. The drivers are retained in the cartridge body by a retainer which extends around the bottom of the cartridge body and includes resilient members configured to grip the cartridge body and hold the retainer to the cartridge body. The drivers are movable between their unfired positions and their fired positions by a sled. The sled is movable between a proximal position adjacent the proximal end and a distal position adjacent the distal end. The sled comprises a plurality of ramped surfaces configured to slide under the drivers and lift the drivers, and the staples supported thereon, toward the anvil.

[0142] Further to the above, the sled is moved distally by a firing member. The firing member is configured to contact the sled and push the sled toward the distal end. The longitudinal slot defined in the cartridge body is configured to receive the firing member. The anvil also includes a slot configured to receive the firing member. The firing member further comprises a first cam which engages the first jaw and a second cam which engages the second jaw. As the firing member is advanced distally, the first cam and the second cam can control the distance, or tissue gap, between the deck of the staple cartridge and the anvil. The firing member also comprises a knife configured to incise the tissue captured intermediate the staple cartridge and the anvil. It is desirable for the knife to be positioned at least partially proximal to the ramped surfaces such that the staples are ejected ahead of the knife.

[0143] An end effector can be configured to articulate relative to the handle and/or shaft of a surgical instrument. For example, the end effector can be pivotably and/or rotatably coupled to the shaft of the surgical instrument such that the end effector is configured to pivot relative to the shaft and the handle. In various instances, the end effector can be configured to articulate at an articulation joint located intermediate the end effector and the shaft. In other instances, the shaft can include a proximal portion, a distal portion, and an articulation joint, which can be located intermediate the proximal portion and the distal portion of the shaft, for example.

[0144] Referring now to FIGS. 1 and 2, an articulation joint 130 of a surgical instrument 100 is partially depicted. The surgical instrument 100 includes a shaft 110 and an articulatable end effector 120. The articulatable end effector 120 shown in FIGS. 1 and 2 is coupled to the shaft 110 of the surgical instrument 100 at the articulation joint 130, which permits articulation of the end effector 120 relative to the shaft 110. A staple cartridge 122 is positioned in the depicted end effector 120. Referring primarily to FIG. 1, the depicted staple cartridge 122 includes a cartridge body 124 having a plurality of staple cavities 126. In various instances, fasteners, such as staples, for example, can be removably positioned in the staple cavities 126.

[0145] In certain instances, the staple cartridge 122 can be removably positioned in the end effector 120 and, in other instances, the staple cartridge 122 can be permanently fixed to and/or integrally formed with the end effector 120. In certain instances, the cartridge body 124 can include a rigid body having defined staples cavities 126. Additionally or alternatively, the cartridge body 124 can include a flexible and/or deformable portion, and staples may be embedded and/or partially embedded in the cartridge body 124.

[0146] A surgical instrument can include a flexible firing bar, which can extend through an articulation joint. In such instances, the flexible firing bar can be configured to bend or flex at the articulation joint when the end effector is in an articulated orientation. In at least one instance, the flexible firing bar can include a plurality of lateral layers or portions. The flexible firing bar can define an inside radius of curvature and an outside radius of curvature at the bend in the articulation joint. For example, the outside lateral portion of the flexible firing bar can extend along a first path that defines an outside radius of curvature within the articulation joint, and the inside lateral portion of the flexible firing bar can extend along a second path that defines an inside radius of curvature within the articulation joint. The outside radius of curvature of the firing bar can be greater than the inside radius of curvature. As a result, the inside lateral portion of the flexible firing bar may extend a greater distance proximally than the outside lateral portion of the flexible firing bar. The radius of curvature of each lateral portion, and thus the relative position of each lateral portion, can be a function of the degree in which the end effector has been articulated.

[0147] As the flexible firing bar flexes at the articulation joint, further to the above, the lateral portions can be configured to shift relative to each other. In various instances, the lateral portions can be coupled together at the distal end, such as by welding, for example. In such instances, the remaining length of each lateral portion, e.g., the non-coupled portions, can be free to shift and/or slide relative to the adjacent lateral portion(s).

[0148] In various instances, as the flexible firing bar flexes and the lateral portions shift, the proximal ends of some of the lateral portions can displace relative to the other lateral portions, for example. In certain instances, the proximal end of at least one lateral portion can be displaced distally and the proximal end of at least one lateral portion can be displaced proximally, for example. In still other instances, the proximal ends of each lateral portion can be displaced and/or pushed proximally, for example. The position of each lateral portion within the shaft and relative to the other lateral portions can depend on the articulation angle of the end effector.

[0149] In various instances, the flexible firing bar can be coupled to a firing rod or beam. The firing rod can be configured to transfer a firing force to the flexible firing bar. In certain instances, the firing rod can be configured to move a predefined distance to displace the flexible firing bar to a predefined distal-most position in the unarticulated end effector. However, when the end effector is articulated and the proximal ends of the lateral portion have been shifted, movement of the firing rod the predefined distance may not displace the flexible firing bar to the predefined distal-most position in the articulated end effector. Rather, when the end effector is articulated, the flexible firing bar may stop short of the predefined distal-most position if the firing rod is only displaced the predefined distance. Moreover, the distal position achieved by the flexible firing bar when the firing rod is displaced a predefined distance can depend on the degree in which the end effector is articulated.

[0150] As a result, when the end effector is articulated, a staple-deploying sled and/or a cutting edge driven through the staple cartridge by the flexible firing bar may not reach the same distal position relative to the distal end of the end effector. Rather, the firing system may stop advancing the sled and/or the cutting edge before the sled and/or the cutting edge reaches the distal position that would be reached if the end effector was unarticulated. Consequently, when the end effector is articulated, the cutting edge may not complete the cutting motion and/or the sled may not complete the firing motion and thus may not fire the staples from the distal-most staple cavities. In various instances, the degree of articulation of the end effector can affect the distal position reached by the flexible firing bar, the staple-deploying sled, and/or the cutting edge during a firing stroke.

[0151] In certain instances, to ensure the flexible firing bar, the staple-deploying sled, and/or the cutting edge reach their intended distal-most positions within the end effector, the firing stroke can be adjusted. For example, when the end effector is articulated, the firing stroke can be adjusted such that the firing rod is displaced a greater distance. In certain instances, the adjustment to the firing stroke can depend on the articulation angle of the end effector. For example, the displacement of the firing rod during an adjusted firing stroke can increase as the articulation angle of the end effector increases.

[0152] Referring to the surgical instrument 100 and components thereof depicted in FIGS. 1-7, the surgical instrument 100 includes a firing system 112, which is configured to transfer a firing motion from the handle of the surgical instrument 100 to the end effector 120. In the depicted embodiment, the firing system 112 includes a firing rod 114, which is coupled to a flexible firing bar 118 at a coupling or connection 116 (FIGS. 3-7). The firing rod 114 can extend into the shaft 110 and can translate in response to driving motions initiated in the handle of the surgical instrument 100. In various instances, the firing rod 114 can resist deformation, torqueing and/or bowing when transferring a firing motion. For example, the firing rod 114 can be comprised of a rigid and/or inflexible material and/or structure.

[0153] At the coupling 116, referring primarily now to FIGS. 3-5, the firing rod 114 is engaged with a key 119 of the flexible firing bar 118. For example, the key 119 can extend into an aperture 115 in the firing rod 114. The firing rod-key engagement is configured to transfer the translation of the firing rod 114 to the flexible firing bar 118. In various instances, the coupling 116 can be proximate to the articulation joint 130 such that the flexible firing bar 118 extends from the coupling 116 and through the articulation joint 130.

[0154] The flexible firing bar 118 includes a plurality of lateral portions or layers 128a, 128b, 128c, 128d. In various instances, the portions 128a, 128b, 128c, 128d can be held together and movable and/or shiftable relative to each other. For example, the lateral portions 128a, 128b, 128c, 128d can be fixed together at the distal end of the flexible firing bar 118. The portions 128a, 128b, 128c, 128d can be welded, formed together, fastened and/or otherwise secured together at the distal ends thereof, for example. At least a portion of the remaining length of the lateral portions 128a, 128b, 128c, 128d can be configured to move and/or shift relative to the adjacent lateral portion(s) 128a, 128b, 128c, 128d. For example, when the flexible firing bar 118 bends at the articulation joint 130, the lateral portions 128a, 128b, 128c, 128d can shift into a staggered and/or offset configuration between the bend in the articulation joint 130 and the proximal end of the flexible firing bar 118, as illustrated in FIG. 6.

[0155] Referring again to FIGS. 1-3, the portions 128a, 128b, 128c, 128d of the flexible firing bar 118 can extend along firing paths through the articulation joint 130. When the end effector 120 is articulated relative to the shaft 110, the flexible firing bar 118 and portions 128a, 128b, 128c, 128d thereof can bend within the articulation joint 130. In such instances, the lateral portions 128a, 128b, 128c, 128d can extend along altered paths when the end effector 120 is articulated.

[0156] For example, referring primarily to FIG. 2, the outside portion 128a can extend along an outside path having an outside radius of curvature, and the inside portion 128d can extend along an inside path having an inside radius of curvature. Due to the deformation of the firing bar 118 within the articulation joint 130, the inside radius of curvature can be different than the outside radius of curvature. For example, referring to FIGS. 1 and 2, the outside radius of curvature is larger than the inside radius of curvature. As a result, referring now to FIG. 6, the portions 128a, 128b, 128c, 128d can become staggered at the proximal end portion 140 of the flexible firing bar 118 when the end effector 120 is in an articulated orientation relative to the shaft 110.

[0157] In certain instances, the shifted proximal end portion 140 of the flexible firing bar 118 and the firing bar portions 128a, 128b, 128c, 128d can ultimately effect the distal position reached by the flexible firing bar 118 during a firing stroke. For example, the distal position reachable by the flexible firing bar 118 during the firing stroke can change as the end effector 120 articulates. As a result, the distal position reached by a staple-deployment sled and/or cutting element during the firing stroke can also be shifted when the end effector 120 is in an articulated orientation.

[0158] In certain instances, it may be desirable to estimate the distance that the flexible-firing bar 118 can be displaced by the firing stroke based on calculations and/or approximations. Such calculations and/or approximations can be based on the degree in which the end effector has been articulated. In still other instances, it may be desirable to monitor and/or otherwise determine the position of the flexible firing bar 118 during the firing stroke. For example, at least one sensor at the distal end, proximal end, and/or intermediate portion of the flexible firing bar 118 can detect the displacement of the flexible firing bar 118 during the firing stroke and/or the shifting of the lateral portions 128a, 128b, 128c, 128d during an articulation motion. In various instances, a sensor can comprise a resistive sensor, inductive sensor, capacitance sensor, and/or a magnetic sensor, for example.

[0159] In various instances, it can be desirable to adjust the firing stroke length based on the position of the flexible firing bar 118 and/or the degree of articulation of the end effector 120. In various instances, a detection system and/or a sensor can be configured to detect the shifting of the lateral portions 128a, 128b, 128c, 128d of the flexible firing bar 118 to determine the degree of articulation of the end effector 120. In certain instances, the detection system and/or the sensor can be positioned proximal to the articulation joint 130. For example, the detection system and/or the sensor can be positioned within the shaft 110 at and/or near the proximal end 140 of the flexible firing bar 118 and/or the lateral portions 128a, 128b, 128c, 128d thereof. In still other instances, a detection system and/or a sensor can be configured to monitor the position of the flexible firing bar 118 during the firing stroke and adjust the firing stroke length based on the detected position of the flexible firing bar 118. For example, the detection system and/or the sensor can be positioned in the end effector 120 and/or distal to the articulation joint 130. In still other instances, such a sensor can be positioned in the shaft 110 of the surgical instrument 100 proximal to the articulation joint 130.

[0160] The surgical instrument 100 can include a sensor, such as a Hall effect sensor and/or a resistive contact, for example, which can be configured to detect shifting of the lateral portions 128a, 128b, 128c, 128d when the end effector 120 is articulated. As described herein, the amount of shifting can correspond to the degree in which the end effector 120 is articulated. A detection system 250 is depicted in FIGS. 6 and 7. The detection system 250 can be configured to detect shifting and/or staggering of the lateral portions 128a, 128b, 128c, 128d at the proximal end 140 of the flexible firing bar 118 (FIGS. 1-7).

[0161] Referring still to FIGS. 6 and 7, the detection system 250 can be mounted and/or otherwise positioned in the shaft 110 of the surgical instrument 100 (FIG. 1). In various instances, the detection system 250 can include at least one magnet and a Hall effect sensor. For example, the depicted detection system 250 includes a series of magnets 252a, 252b, 252c, 252d and 252e and a Hall effect sensor 254, for example. The magnets 252a, 252b, 252c, 252d and 252e are positioned on the firing bar 118. For example, the magnets 252a, 252b, 252c, 252d and 252e are spaced along the proximal end portion 140 of the firing bar 118 within the coupling 116.

[0162] As depicted in FIG. 6, the magnets 252a, 252b, 252c, 252d and 252e can be mounted to at least one of the lateral portions 128a, 128b, 128c, 128d of the flexible firing bar 118. In the depicted arrangement, the magnets 252a, 252b, 252c, 252d and 252e are mounted to the fourth portion 128d. Moreover, the Hall effect sensor 254 can also be positioned in the shaft 110. For example, the Hall effect sensor 254 can be mounted on the shaft 110 above the proximal end portion 140 of the firing bar 118. In such instances, the Hall effect sensor 254 can be fixed and/or stationary relative to the shaft 110 and the magnets 252a, 252b, 252c, 252d and 252e can be configured to move relative to the sensor 254 when the end effector 120 is articulated.

[0163] In certain instances, the detection system 250 can include less than or more than the five magnets 252a, 252b, 252c, 252d and 252e depicted in FIGS. 6 and 7. Furthermore, the magnets 252a, 252b, 252c, 252d and 252e may be mounted to and/or on a plurality of the lateral portions 128a, 128b, 128c, 128d. Moreover, as described herein, at least one Hall effect sensor can be mounted to one or more of the lateral portions 128a, 128c, 128c, 128d.

[0164] The magnets can include permanent magnets and/or electromagnets, for example. In certain instances, the portions 128a, 128b, 128c, 128d can include a ferrous material, for example, which can form the magnets of the detection system 250. For example, the ferrous material can be embedded in the lateral portions 128a, 128b, 128c, 128d, and/or can comprise a coating around a region of the lateral portions 128a, 128b, 128c, 128d.

[0165] Due to the arrangement of the various components of the detection system 250, the detection system 250 can be configured to detect the amount of firing bar stagger that occurs when the end effector 120 (FIG. 1) is moved to an articulated orientation. In various instances, as the firing bar 118 bends in the articulation joint 130, the lateral portions 128a, 128b, 128c, 128d can shift, such that the proximal ends of the portions 128a, 128b, 128c, 128d are displaced. As the portions 128a, 128b, 128c, 128d shift relative to each other, the magnets 252a, 252b, 252c, 252d and 252e mounted to the fourth portion 128d can also shift. In such instances, the Hall effect sensor 254 can detect the displacement of the magnets 252a, 252b, 252c, 252d and 252e. Based on the detected displacement of the magnets 252a, 252b, 252c, 252d and 252e, the degree of end effector articulation can be determined and/or estimated.

[0166] In various instances, the detection system 250 can be in communication with a controller, which can be configured to detect the articulation angle based on feedback from the Hall effect sensor 254. Additionally or alternatively, the controller can be configured to adjust the length of the firing stroke based on the calculated and/or estimated degree of end effector articulation based on the detected stagger and/or offsets between the portions 128a, 128b, 128c, 128d. In such instances, the controller can adjust the firing stroke length such that the flexible firing bar 118 reaches a predefined distal-most position in the end effector 120, i.e., the same predefined distal-most position that the firing bar 118 reaches when the end effector 120 is in an unarticulated position.

[0167] In various instances, an encoding system can be configured to detect and/or determine the degree of articulation of an end effector. For example, referring now to FIG. 8, a flexible firing bar 318 can be coupled to the firing rod 114 at the coupling 316. Similar to the flexible firing bar 118 (FIGS. 1-7), the flexible firing bar 318 is configured to transfer a firing motion from the firing rod 114, through the articulation joint 130 (FIGS. 1 and 2), and to the end effector 120 (FIGS. 1 and 2). The flexible firing bar 318 can include a plurality of lateral portions 328a, 328b, 328c, and 328d, which can shift relative to each other when the end effector 120 is articulated. Similar to the above, the proximal ends of the portions 328a, 328b, 328c, and 328d can become staggered, as illustrated in FIG. 8. The portions 328a, 328b, 328c, and 328d can include uneven and/or irregular sections 352 at the proximal end portion 340 of the flexible firing bar 318.

[0168] In the depicted embodiment, each uneven section 352 includes a plurality of teeth 354. In other instances, each uneven section 352 can include a single tooth 354. Additionally or alternatively, at least one uneven section 352 can define a plurality of contours, angled portions, valleys and/or peaks. In certain instances, the teeth 354 can define contoured and/or rounded valleys and/or peaks, for example, such that the teeth 354 form a rolling and/or undulating profile, for example. In certain instances, two or more of the lateral portions 328a, 328b, 328c, 328d can include a uneven section 352. In some instances, each lateral portion 328a, 328b, 328c, 328d can include at least one uneven section 352. In various instances, at least two uneven sections 352 can define a different profile.

[0169] Referring still to FIG. 8, a linear encoding system 350 is depicted. The linear encoding system 350 includes a signal generator 356 and a signal receiver 358. The signal generator 356 can be configured to send signals to the signal receiver 358. As the signals pass the uneven section(s) 352 of the portion(s) 328a, 328b, 328c, and 328d, at least some of the signals can be deflected and/or diverted. Moreover, as the uneven sections 352 are displaced, staggered and/or otherwise affected when the end effector 120 is articulated, the signal receiver 358 can detect the change in the signal that is received and determine the relative arrangement of the laterals portions 328a, 328b, 328c, 328d, and thus determine the degree of articulation of the end effector 120.

[0170] In various instances, the detection system 350 can be in communication with a controller which can be configured to detect the articulation angle of the end effector 120 based on feedback from the receiver 358. Additionally or alternatively, the controller can be configured to adjust the length of the firing stroke based on the detected stagger and/or offsets between the portions 328a, 328b, 328c, 328d, which are used to calculate and/or estimate the degree in which the end effector has been articulated. In such instances, the controller can adjust the firing stroke length such that the flexible firing bar 318 reaches a predefined distal-most position in the end effector, i.e., the same predefined distal-most position that the firing bar 118 reaches when the end effector 120 is in an unarticulated position.

[0171] In various instances, the encoding system 350 can include an optic, magnetic, and/or capacitive encoder, for example. In certain embodiments, the signal generator 356 can generate a wave, such as a light wave, radio wave, microwave, and/or x-ray, for example. In some instances the signal generator 356 can generate a plurality of laser signals, for example.

[0172] In certain instances, an electrically-conductive material can be configured to detect the amount of stagger between the lateral portions of a firing bar. Referring now to FIGS. 9 and 10, a band 450 is secured to the proximal end of a flexible firing bar 418. Similar to the flexible firing bar 118 (FIGS. 1-7), the flexible firing bar 418 is configured to transfer a firing motion from the firing rod 114, through the articulation joint 130 (FIGS. 1 and 2), and to the end effector 120 (FIGS. 1 and 2). The flexible firing bar 418 includes a plurality of lateral portions 428a, 428b, 428c, and 428d, which can shift relative to one another when the end effector 120 is articulated. In such instances, the proximal ends of the portions 428a, 428b, 428c, and 428d become staggered.

[0173] The depicted band 450 includes a first end 452, which is a secured to the fourth portion 428d, and a second end 454, which is secured to the first portion 428a. As the portions 428a, 428b, 428c, 428d shift relative to each other when the end effector 120 is articulated, the band 450 can stretch to accommodate the staggered proximal ends of the portions 428a, 428b, 428c, 428d. For example, the band 450 can stretch as the end effector 120 is moved from an unarticulated orientation (FIG. 9) to an articulated orientation (FIG. 10). In such instances, the band 450 can continue to stretch as the portions 428a, 428b, 428c, 428d continue to stagger in response to articulation of the end effector 120. For example, as the articulation angle of the end effector 120 increases, the portions 428a, 428b, 428c, 428d can become more staggered and the band 450 can become more stretched.

[0174] Referring still to FIGS. 9 and 10, the depicted band 450 is secured to the outside portions 428a, 428d of the flexible firing bar 418. Moreover, the band 450 is configured to extend around the proximal end 440 of the flexible firing bar 418. For example, the band 450 depicted in FIGS. 9 and 10 extends around the proximal end 440 of the flexible firing bar 418 and extends past the proximal ends of the intermediate or inside portions 428b and 428c.

[0175] In other instances, the band 450 can extend around the perimeter of the flexible firing bar 418 proximal to the distal end 440. In still other instances, the band 450 can extend between adjacent lateral portions of the flexible firing bar 418, such as the inside portions 428b and 428c, for example. Additionally or alternatively, a plurality of flexible bands can be mounted to the flexible firing bar 418.

[0176] In various instances, the flexible band 450 can include an electrically-active polymer, for example. In such instances, as the flexible band 450 stretches, the electrically-active polymer can provide a signal that is indicative of the amount of band stretch, and thus, the amount of firing bar stagger. In other instances, the band 450 could be comprised of other conductive materials having different electrical characteristics reflective of the strain in the band.

[0177] In various instances, the flexible band 450 can be in communication with a controller, which can be configured to detect the articulation angle based on feedback from the band 450. For example, the strain in the band 450 can be a function of the degree in which the end effector is articulated. More particularly, the strain can correspond to the voltage potential, which can be detectable by the controller. For example, the controller can detect a greater voltage potential when the strain in the band 450 is greater, which corresponds to a larger articulation angle of the end effector 120. Moreover, if the end effector 120 is less articulated relative to the shaft 110, i.e., if the articulation angle of the end effector 120 is reduced, the controller can detect a reduced voltage potential, which corresponds to a reduced strain in the band 450. The adjustment to the firing stroke length can depend on the degree in which the end effector 120 has been articulated and can be independent of the direction of articulation. For example, when the end effector 120 has been articulated x° to the right or x° to the left, the firing stroke length can be increased by a distance z.

[0178] Additionally or alternatively, the controller can be configured to adjust the length of the firing stroke based on the detected stagger and/or offsets between the portions 428a, 428b, 428c, 428d, which are used to calculate and/or estimate the degree in which the end effector 120 has been articulated. In such instances, the controller can adjust the firing stroke length such that the flexible firing bar 418 reaches a predefined distal-most position in the end effector 120, i.e., the same predefined distal-most position that the firing bar 418 reaches when the end effector is in an unarticulated position.

[0179] In various instances, at least one Hall effect sensor positioned on a flexible firing bar can be configured to detect shifting of the lateral portions of the flexible firing bar. Referring now to FIGS. 11 and 12, a detection system 550 is depicted at the proximal end 540 of a flexible firing bar 518. Similar to the flexible firing bar 118 (FIGS. 1-7), the flexible firing bar 518 is configured to transfer a firing motion from the firing rod 114, through the articulation joint 130 (FIGS. 1 and 2), and to the end effector 120 (FIGS. 1 and 2). The flexible firing bar 518 includes a plurality of lateral portions 528a, 528b, 528c, and 528d, which can shift when the end effector 120 is articulated. In such instances, the proximal ends of the portions 528a, 528b, 528c, and 528d become staggered.

[0180] The depicted detection system 550 includes a magnet 552 and a Hall effect sensor 554. The magnet 552 and the Hall effect sensor 554 are located on opposite lateral sides of the flexible firing bar 518. For example, the magnet 552 can be positioned on an outside portion of the flexible firing bar 518, such as fourth portion 528d, for example, and the Hall effect sensor 554 can be positioned on the other outside portion of the flexible firing bar 518, such as first portion 528a, for example.

[0181] As the end effector 120 moves from an unarticulated orientation (FIG. 11) to an articulated orientation (FIG. 12), the lateral portions 528a, 528b, 528c, 528d of the flexible firing bar 518 can shift relative to each other. As a result, the distance between the magnet 552 on the outside portion 528d and the Hall effect sensor 554 on the outside portion 528a can change. For example, referring still to FIGS. 11 and 12, the magnet 552 and the sensor 554 can be separated by a distance d when the end effector is in an unarticulated orientation (FIG. 11), and can be separated by a distance d′, which is greater than distance d, when the end effector is in an articulated orientation (FIG. 12).

[0182] In certain instances, the detection system 550 can further include an electrically-conductive guide or contact slide 556. The contact slide 556 can be configured to guide and/or protect the Hall effect sensor 554 as the sensor 554 shifts in the shaft 110. In various instances, the contact slide 556 can be mounted to and/or formed on the firing rod 114. For example, the contact slide 556 can be defined on a surface of the firing rod 114 and/or along at least a portion the aperture 115.

[0183] In various instances, the contact slide 556 can provide power to the Hall effect sensor 554. For example, the contact slide 556 can be coupled to a power source and the Hall effect sensor 554. In such instances, the Hall effect sensor 554 can be configured to remain in sliding contact with the contact slide 556 as the end effector 120 moves from an unarticulated orientation to an articulated orientation. The detection system 550 can further include a second contact slide, which can provide a return path from the Hall effect sensor 554 to the remainder of the circuit. Additionally or alternatively, in instances where the magnet 552 requires power, a pair of contact slides can provide power to the magnet 552.

[0184] The degree in which the end effector 120 has been articulated can be based on the firing bar stagger detected by the detection system 550. Moreover, the detection system 550 can be in communication with the controller, which can adjust the length of the firing stroke based on the amount of firing bar stagger and the associated degree of end effector articulation. In such instances, the controller can adjust the firing stroke length such that the flexible firing bar 518 reaches a predefined distal-most position in the end effector 120, i.e., the same predefined distal-most position that the firing bar 518 reaches when the end effector is in an unarticulated position.

[0185] Referring now to FIGS. 13 and 14, a flexible firing bar 618 is depicted. In various instances, the flexible firing bar 618 can be used in the firing system 112 of the surgical instrument 100 (FIG. 1), for example. The flexible firing bar 618 includes a plurality of lateral portions 628a, 628b, 628c, 628d. When the end effector 120 (FIG. 1) is unarticulated relative to the shaft 110, referring primarily to FIG. 13, the lateral portions 628a, 628b, 628c, 628d are staggered and/or offset from each other at the proximal end 640 of the firing bar 618. In various instances, the lateral portions 628a, 628b, 628c, 628d can be different lengths. For example, the inside portions 628b and 628c can be longer than the outside portions 628a and 628d by a length x. As a result, the outside portions 628a, 628d are staggered relative to the inside portions 628b, 628c by the length x.

[0186] Referring primarily to FIG. 14, when the end effector 120 (FIG. 1) is articulated relative to the shaft 110, the lateral portions 628a, 628b, 628c, 628d can shift relative to each other. For example, the proximal ends of the portions closer to the inside of the curvature, i.e., the portions 628c and 628d in FIG. 14, can shift proximally relative to the portions closer to the outside of the curvature, i.e., the portions 628a and 628b. In certain instances, the fourth portion 628d can shift toward alignment with the third portion 628c and/or proximally past the third portion 628c, for example. Additionally, the portions closer to the outside of the curvature, i.e., the portions 628a and 628b in FIG. 14, can shift distally relative to the portions closer to the inside of the curvature, i.e., the portions 628c and 628d. In certain instances, the second portion 628c can shift out of alignment with the third portion 628b, for example.

[0187] In certain instances, a sensor can be configured to detect the shifting of the lateral portions 628a, 628b, 628c, 628d when the end effector 120 (FIG. 1) is articulated. For example, a proximity sensor can be positioned in the shaft 110 to monitor and/or detect the changing positions of the proximal ends of the lateral portions 628a, 628b, 628c, 628d. The sensor can comprise a resistive sensor, inductive sensor, capacitance sensor, and/or a magnetic sensor, for example.

[0188] In various instances, the sensor can be in communication with a controller, which can be configured to detect the articulation angle of the end effector 120 based on feedback from the sensor. Additionally or alternatively, the controller can be configured to adjust the length of the firing stroke based on the detected stagger and/or offsets between the portions 628a, 628b, 628c, 628d, which are used to calculate and/or estimate the degree in which the end effector has been articulated. In such instances, the controller can adjust the firing stroke length such that the flexible firing bar 618 reaches a predefined distal-most position in the end effector, i.e., the same predefined distal-most position that the firing bar 618 reaches when the end effector 120 is in an unarticulated position.

[0189] As discussed above, a firing bar extending through an articulation joint into an end effector can be bent as the end effector is articulated. In various instances, an electrical circuit on a flexible firing bar can be configured to detect the amount in which the portions of the firing bar shift as the firing bar is bent during the articulation motion. Referring now to FIG. 15, a flexible firing bar 718 is coupled to the firing rod 114 at a coupling 716. Similar to the flexible firing bar 118 (FIGS. 1-7), the flexible firing bar 718 is configured to transfer a firing motion from the firing rod 114, through the articulation joint 130 (FIGS. 1 and 2), and to the end effector 120 (FIG. 1) of the surgical instrument 100. The flexible firing bar 718 includes a plurality of lateral portions 728a, 728b, 728c, and 728d, which shift when the end effector 120 is articulated. In such instances, the proximal ends of the lateral portions 728a, 728b, 728c, and 728d become staggered.

[0190] Referring still to FIG. 15, a detection system 750 is depicted. The detection system 750 includes an electrical circuit having a first contact 752 and a second contact 754. The electrical circuit can be configured to detect the amount of firing bar stagger as the end effector 120 (FIG. 1) is articulated. In various instances, the first contact 752 and the second contact 754 can be mounted between two or more lateral portions 728a, 728b, 728c, 728d of the firing bar 718. For example, the first contact 752 can be mounted to and/or integrally formed with one of the lateral portions, such as the first portion 728a, for example, and the second contact 754 can be mounted to and/or integrally formed with an adjacent lateral portion, such as the second portion 728b, for example.

[0191] Referring still to FIG. 15, the contacts 752, 754 can be positioned on the keys 719 of each lateral portions 728a, 728b. Further to the above, each key 719 can extend into an aperture 115 in the firing rod 114. The firing rod-key engagement is configured to transfer the translation of the firing rod 114 to the flexible firing bar 118. As the first portion 728a shifts relative to the second portion 728b, the first contact 752 can move relative to the second contact 754, for example. Alternatively, the second contact 754 can move relative to the first contact 752 when the second portion 728b moves relative to the first portion 728a.

[0192] In various instances, the second contact 754 can comprise a flexible circuit having a variable size along the longitudinal axis. For example, the flexible circuit can define a wavy tracing pattern. In various instances, the second contact 754 can comprise a toothed and/or geared face 766. Ridges and/or teeth 762 can protrude from the face 766 of the second contact 754 and/or grooves 764 can be defined into the face 766 of the second contact 754. In the depicted embodiment, the length of the ridges 762 and grooves 764 varies along the length of the face 766 to form the wavy tracing pattern. As a result, the face 766 defines a plurality of discrete locations of different sizes and/or lengths. Referring still to FIG. 15, an insulated area 758 can extend around the face 766 of the second contact 754. In various instances, the first contact 752 can comprise a single contact edge. As depicted in FIG. 15, an insulated area 756 can be positioned on both sides of the first contact 752.

[0193] Referring still to FIG. 15, the second contact 754 can be coupled to a lead 760b, which can connect the second contact 754 to the rest of the circuit. In various instances, a lead, such as the lead 760a, for example, can connect the first contact 752 to the rest of the circuit.

[0194] In various instances, the detection system 750 can include multiple pairs of contacts similar to the contacts 752, 754, for example. For example, a contact can be positioned on one or both sides of each key 719. In certain instances, the detection system 750 can further include an electrical lead, such as leads 760a, 760b, 760c, 760d, for example, which can extend to each lateral portion 728a, 728b, 728c, 728d, respectively, for example. The leads 760a, 760b, 760c, 760d can be configured to couple an electrical contact on each lateral portion 728a, 728b, 728c, 728d to the remainder of the circuit.

[0195] As the first contact 752 shifts relative to the second electrical contact 754 when the end effector is articulated, referring still the FIG. 15, the detection system 750 can detect a change in capacitance. The variable length of ridges 762 and grooves 764 along the face 766 of the second contact 754 can affect a change in capacitance between the two contacts 752, 754. For example, the capacitance can be greatest when the first contact 752 is aligned with the longest ridge 762 of the second contact 754. In various instances, the first contact 752 can be aligned with the longest ridge 762 of the second contact 754 when the end effector 120 is unarticulated. As the end effector 120 is articulated and the lateral portions shift, the first contact 752 can move away from the longest ridge 762 and into alignment with a shorter ridge 762. In such instances, the capacitance in the detection system 750 can decrease as the end effector is articulated.

[0196] In certain instances, referring now to FIG. 16, the capacitance can diminish throughout the range of end effector articulation from an unarticulated orientation to an articulated orientation. More particularly, the capacitance can diminish as the end effector is articulated to the right from an unarticulated or less articulated position. Similarly, the capacitance can diminish as the end effector is articulated to the left from the unarticulated or less articulated position. Moreover, as the end effector moves from an articulated position toward the unarticulated position, the capacitance can increase.

[0197] In various instances, one or both of the contacts 752, 754 can define an alternative geometry. In certain instances, the contacts 752, 754 can comprise planar surfaces, which can shift into and/or out of alignment as the end effector 120 is articulated. In such instances, the varying alignment and/or overlap between the planar surfaces can correspond to a change in capacitance. For example, the capacitance can be greatest when the alignment between the planar contacts is the greatest. In other instances, one of the contacts 752, 754 can comprise a planar surface, for example.

[0198] In various instances, the detection system 750 can be in communication with a controller, which can be configured to detect the articulation angle of the end effector 120 based on feedback from the sensor 754. Additionally or alternatively, the controller can be configured to adjust the length of the firing stroke based on the detected stagger and/or offsets between the portions 728a, 728b, 728c, 728d, which are used to calculate and/or estimate the degree in which the end effector has been articulated. In such instances, the controller can adjust the firing stroke length such that the flexible firing bar 718 reaches a predefined distal-most position in the end effector 120, i.e., the same predefined distal-most position that the firing bar 718 reaches when the end effector 120 is in an unarticulated position. The adjustment to the firing stroke length can depend on the degree in which the end effector 120 has been articulated and can be independent of the direction of articulation. For example, when the end effector 120 has been articulated x° to the right or x° to the left, the firing stroke length can be increased by a distance z.

[0199] In certain instances, a detection system can include at least one rotary encoder, which can be configured to detect the linear travel of a flexible firing bar. A detection system 850 is depicted in FIG. 17. The detection system 850 includes rotary encoders 852 and 854. The rotary encoders 852 and 854 are positioned adjacent to a flexible firing bar 818. Similar to the flexible firing bar 118 (FIGS. 1-7), the flexible firing bar 818 is configured to transfer a firing motion from the firing rod 114, through the articulation joint 130 (FIGS. 1 and 2), and to the end effector 120 (FIG. 1) of the surgical instrument 100. The flexible firing bar 818 includes a plurality of lateral portions 828a, 828b, 828c, and 828d which can shift relative to one another when the end effector 120 is articulated such that the proximal ends of the lateral portions 828a, 828b, 828c, and 828d become staggered.

[0200] In various instances, the rotatory encoder(s) 852, 854 can be configured to detect the linear displacement of the flexible firing bar 818 and/or portions 828a, 828b, 828c, and 828d thereof. For example, as the end effector 120 articulates, at least one rotary encoder 852, 854 can detect the displacement of the flexible firing bar 818 during the articulation motion.

[0201] In various instances, as depicted in FIG. 17, a rotary encoder 852, 854 can be positioned on each side of the flexible firing bar 818, and can detect the displacement of the outside portions 828a and 828d. For example, the first rotary encoder 852 can detect the linear displacement of the fourth lateral portion 828d, and the second rotary encoder 854 can detect the linear displacement of the first lateral portion 828a. Based on the difference between the linear displacement of the outside portions 828a, 828d, the overall stagger between the lateral portions of the firing bar 818 can be determined which can correspond to the degree in which the end effector 120 has been articulated.

[0202] Additionally or alternatively, the detection system 850 can be configured to detect the linear displacement of the flexible firing bar 818 during the firing stroke. The detection system 850 can be positioned at and/or near the distal portion of the shaft 110 and/or distal to the articulation joint 130 (FIGS. 1 and 2), for example. In other instances, the detection system 850 can be positioned at and/or near the proximal portion of the shaft 110, for example and/or proximal to the articulation joint 130.

[0203] In various instances, the rotary encoders 852, 854 can be configured to guide the flexible firing bar 818 when the end effector 120 is articulated and/or when the firing bar 818 is advanced distally during a firing stroke. For example, the rotary encoders 852, 854 can seek to prevent and/or restrain bowing and/or buckling of the flexible firing bar 818. The rotary encoders 852, 854 are positioned on opposite sides of the firing bar 818 and can apply a pinching force thereto which inhibits relative lateral movement between the lateral portions of the firing bar 818.

[0204] In various instances, the detection system 850 can be in communication with a controller which can be configured to detect the articulation angle of the end effector 120 based on feedback from the encoders 852, 854. Additionally or alternatively, the controller can be configured to adjust the length of the firing stroke of the firing bar 818 based on the detected stagger and/or offsets between the portions 828a, 828b, 828c, 828d, which is used to calculate and/or estimate the degree in which the end effector 120 has been articulated. In such instances, the controller can adjust the firing stroke length such that the flexible firing bar 818 reaches a predefined distal-most position in the end effector 120, i.e., the same predefined distal-most position that the firing bar 818 reaches when the end effector 120 is in an unarticulated position.

[0205] In certain instances, a detection system can include a laser, for example, which can be configured to detect shifting and/or staggering of the lateral portions of a flexible firing bar. Referring now to FIG. 18, a detection system 950 and a flexible firing bar 918 are depicted. In various instances, the flexible firing bar 918 can be coupled to a firing rod, such as the firing rod 114, for example, and used in the firing system 112 of the surgical instrument 100 (FIG. 1), for example. As depicted in FIG. 18, the flexible firing bar 918 includes a plurality of lateral portions, which shift relative to each other when the end effector 120 (FIG. 1) is articulated.

[0206] As illustrated in FIG. 18, a plurality of apertures 956 are defined in the lateral portions of the flexible firing bar 918. The apertures 956 comprise circular apertures, for example, defined through the lateral portions. In other instances, the apertures can comprise an elongated and/or polygonal geometry, for example. When the end effector 120 is in an unarticulated position, the apertures 956 in a lateral portion are aligned with the apertures 956 in the adjacent lateral portions. As the lateral portions of the flexible firing bar 918 shift relative to one another when the end effector 120 is articulated, the apertures 956 defined through each lateral portion can shift. In various instances, the apertures 956 can shift into and/or out of alignment with the apertures 956 in the other lateral portions. In certain instances, the apertures 956 can be aligned when the end effector 120 is unarticulated, and can shift out of alignment during an articulation motion while, in other instances, the apertures 956 can be aligned when the end effector 120 is fully articulated.

[0207] The detection system 950 depicted in FIG. 18 includes an optical laser 952. The optical laser 952 can be coupled to an optical conduit or light pipe 954, which can extend through the shaft 110, and may extend to the handle of the surgical instrument 100, for example. In various instances, the optical laser 952 can be configured to generate a laser beam and/or a plurality of laser beams. The detection system 950 can further comprise a receiver configured to detect the laser beam(s). When the apertures 956 are aligned with each other, the laser beam(s) can be transmitted through the lateral portions without being blocked by the lateral portions. When the apertures 956 are only partially aligned with one another, the laser beam(s) may be partially blocked by the lateral portions. When the apertures 956 are not aligned with each other at all, the laser beam(s) can be completely blocked by the lateral portions. The laser signal received by the receiver can correspond to the shifting of the alignment of the apertures, which can correspond to the shifting of the lateral portions of the flexible firing bar 918.

[0208] In various instances, the detection system 950 can be in communication with a controller. The controller can be configured to detect the articulation angle of the end effector 120 based on feedback from the detection system 950. Additionally or alternatively, the controller can be configured to adjust the length of the firing stroke based on the calculated and/or estimated degree of end effector articulation based on the detected stagger and/or offsets between the lateral portions. In such instances, the controller can adjust the firing stroke length such that the flexible firing bar 918 reaches a predefined distal-most position in the end effector 120, i.e., the same predefined distal-most position that the firing bar 918 reaches when the end effector 120 is in an unarticulated position.

[0209] With respect to the various detection systems disclosed herein, such as the detection systems 250, 350, 550, 650, 750, 850, and 950 and band 450, for example, a controller can be in communication with the detection system and can adjust the firing stroke length based on feedback from the detection system. For example, when the detection system detects a degree of articulation of the end effector, the firing stroke length can be extended to account for the degree of articulation. In various instances, the greater the degree of end effector articulation detected by the detection system, the more the firing stroke length can be extended. The adjustment to the firing stroke length can depend on the articulation angle of the end effector and can be independent of the direction of articulation. In various instances, the controller can include and/or communicate with a microprocessor having a lookup table. Such a lookup table can be integral to and/or accessible by the microprocessor. The lookup table can be stored in virtual memory or physical memory, for example. The lookup table can include a firing stroke adjustment amount for specific articulation angles and/or for specific firing bar stagger amounts. For example, for a given amount of stagger between two lateral portions of a flexible firing bar, the lookup table can indicate a suitable firing stroke adjustment length.

[0210] As described herein, in certain instances, it can be desirable to monitor the linear displacement of a flexible firing bar and/or the shifting of the lateral portions thereof to determine the degree in which the end effector has been articulated. Moreover, the firing stroke length of the firing bar can be adjusted to account for the changing position of the flexible firing bar and/or the portions thereof when the end effector has been articulated. Additionally or alternatively, it can be desirable to provide a relief feature that is configured to absorb and/or otherwise account for changes in the firing stroke length. Such a relief feature can be positioned in the shaft and/or the end effector of a surgical instrument, for example.

[0211] If the firing stroke length is not adjusted to account for the articulation angle of the end effector, the flexible firing bar will extend farther distally for a given firing stroke length when the end effector is unarticulated compared to when the end effector is articulated. The distal-most position of the flexible firing bar during a firing stroke will change as the articulation angle changes. For example, for a given firing stroke length, the flexible firing bar will stop at a more proximal distal-most position when the end effector is articulated compared to when the end effector is unarticulated. Moreover, for a given firing stroke length, the flexible firing bar will stop at a more distal distal-most position when the end effector is less articulated compared to when the end effector is more articulated.

[0212] To ensure the flexible firing bar, staple-deploying sled, and/or cutting edge at least reach their intended distal-most positions within the end effector even when the end effector is fully articulated, the firing stroke length can be selected such that the flexible firing bar extends to the desired distal-most position when the end effector is fully articulated. As a result, the flexible firing bar would extend distally past the desired distal-most position when the end effector is partially articulated or unarticulated. In such instances, the staple-deploying sled and/or other elements of the firing system may collide with the distal end wall of the staple cartridge. To reduce the effect and/or at least partially absorb the impact of the collision, a relief feature can engage the firing system.

[0213] In various instances, a relief feature can be placed in the shaft of a surgical instrument. For example, a relief feature can be positioned at the coupling between a firing rod and a flexible firing bar. Such a relief feature can be configured to absorb and/or conform to changes in the firing stroke length when an end effector of the surgical instrument is moved to an articulated orientation. For example, the relief feature can be comprised of a flexible, deformable and/or elastic material.

[0214] Referring now to FIG. 19, a deformable relief joint 1050 is depicted. In the depicted embodiment, a flexible firing bar 1018 is coupled to the firing rod 114 at a coupling 1016 in the shaft 110 of the surgical instrument 100 (FIG. 1). Similar to the flexible firing bar 118 (see, e.g., FIGS. 1-7), the flexible firing bar 1018 is configured to transfer a firing motion from the firing rod 114, through the articulation joint 130 (FIGS. 1 and 2), and to the end effector 120 (FIG. 1).

[0215] In the depicted embodiment, the stroke compensation member or relief joint 1050 is positioned in the coupling 1016 intermediate the firing rod 114 and a proximal end portion 1040 of the flexible firing bar 1018. The relief joint 1050 can be configured to deform as the proximal end 1040 of the flexible firing bar 1018 is pushed and/or displaced proximally. For example, the proximal end 1040 of the flexible firing bar 1018 and/or portions thereof can be shifted proximally when the end effector 120 is articulated. As the flexible firing bar 1018 moves proximally, the proximal end 1040 can compress the relief joint 1050.

[0216] In various instances, the relief joint 1050 can be comprised of a flexible, deformable, and/or elastic material. For example, the relief joint 1050 can be comprised of a material having a lower durometer hardness than the flexible firing bar 1018 and/or the proximal end 1040 thereof. Additionally or alternatively, the relief joint 1050 can be comprised of a material having a lower durometer hardness than the firing rod 114.

[0217] Referring primarily to FIG. 19, the relief joint 1050 includes a tapered receptacle 1052, which can be configured to receive the proximal end 1040 of the flexible firing bar 1018. The tapered receptacle 1052 can define a conical shape, for example. In such instances, the tapered receptacle 1052 can taper from a wider opening in the distal region of the receptacle 1052 to a narrower opening at an intermediate region in the receptacle 1052. The receptacle 1052 can be closed at the proximal region thereof. In certain instances, the tapered receptacle 1052 can act as a brake, which can initially slow and/or resist proximal displacement of the flexible firing bar 1018 (FIG. 20). Moreover, as the tapered receptacle 1052 is compressed by the firing bar 1018, the receptacle 1052 can stop and/or prevent further proximal displacement of the flexible firing bar 1018 (FIG. 21).

[0218] In certain instances, the flexible firing bar 1018 can include a plurality of lateral portions 1028a, 1028b, 1028c, and 1028d. Referring to FIGS. 19-21, the lateral portions 1028a, 1028b, 1028c, and 1028d can be fixed and/or banded together, for example, at the proximal end 1040 of the flexible firing bar 1018. In such instances, the lateral portions 1028a, 1028b, 1028c, and 1028d can be configured to move together at the proximal end 1040 as depicted in FIGS. 19-21. In other instances, the lateral portions 1028a, 1028b, 1028c, and 1028d can shift when the end effector 120 is articulated such that the proximal ends of the lateral portions 1028a, 1028b, 1028c, and 1028d become staggered. In such instances, the relief joint 1050 can be configured to absorb and/or accommodate the staggered displacement of the lateral portions 1028a, 1028b, 1028c, and 1028d.

[0219] As described herein, in certain instances, the firing stroke can be adjusted and/or modified such that the flexible firing bar 1018 reaches a predefined distal-most position in the end effector 120 when the end effector 120 is fully articulated. In certain instances, the firing stroke can be adjusted and/or modified regardless of the degree in which the end effector 120 has been articulated. In such instances, the flexible firing bar 1018 can be advanced distally beyond the predefined distal-most position in the end effector 120 when the end effector 120 is only partially articulated and/or unarticulated. Moreover, when the end effector 120 is only partially articulated and/or unarticulated, the flexible firing bar 1018 can drive a sled distally into abutting contact with the distal end of the end effector 120 during a firing motion. In such instances, the relief joint 1010 can at least partially absorb the impact of a collision between the sled and the distal end of the end effector 120.

[0220] Further to the above, the relief joint 1050 can be comprised of an elastic material which can compress and/or deform to absorb and/or accommodate proximal displacement of the flexible firing bar 1018. In certain instances, the relief joint 1050 can comprise a spring and/or spring-like feature, for example. Additionally or alternatively, the relief joint 1050 can comprise a friction-slip feature, such as a clutch and/or damper, for example.

[0221] As discussed above, the relief joint 1050 can be positioned at the proximal end 1040 of the flexible firing bar 1018. Additionally or alternatively, a relief feature can be positioned at the distal end of the flexible firing bar 1018. For example, such a relief feature could be positioned between the distal end of the flexible firing bar 1018 and a sled and/or a firing member in the end effector 120 (FIG. 1).

[0222] Referring now to FIG. 22, a stroke adjustment member or relief feature 1150 is depicted. The relief feature 1150 is positioned distal to a distal end 1140 of a flexible firing bar 1118. Similar to the flexible firing bar 118 (FIGS. 1-7), the flexible firing bar 1118 can be configured to transfer a firing motion from the firing rod 114 (see, e.g., FIGS. 1 and 3), through the articulation joint 130 (FIGS. 1 and 2), and to an end effector, such as the end effector 1120, for example. The distal end 1140 of the flexible firing bar 1118 is depicted in FIG. 22, which is coupled to a firing member 1154, for example.

[0223] Referring still to FIG. 22, the firing member 1154 is configured to slide and/or move along at least a portion of a longitudinal slot 1152 defined in a staple cartridge 1122. The firing member 1154 includes a cutting edge 1156 which is configured to sever tissue clamped against the staple cartridge 1122 by an anvil of the end effector 1120. During a firing stroke, distal displacement of the flexible firing bar 1118 can drive the cutting member 1154 distally in order to cut tissue.

[0224] Referring still to FIG. 22, a sled or staple-deployment wedge 1158 can be movably positioned in the staple cartridge 1122. For example, the sled 1158 can include an intermediate portion 1159 that is configured to slide along at least a portion of the longitudinal slot 1152. In various instances, the sled 1158 can further include a plurality of driving wedges, which can be configured to engage staples and/or staples drivers to eject the staples from the staple cavities 1126, and move the staples toward the anvil of the end effector 1120.

[0225] The relief feature 1150 is positioned intermediate the firing member 1154 and the sled 1158. In at least one instance, the relief feature 1150 can be coupled to the sled 1158 by a tongue-and-groove engagement. As depicted in FIG. 22, the relief feature 1150 includes a tongue 1162 and the sled 1158 includes a groove 1164 that is configured to receive and hold the tongue 1162. For example, the tongue 1162 can be friction-fit and/or otherwise retained in the groove 1164.

[0226] In certain instances, the relief feature 1150 can be integrally formed with the sled 1158. In various instances, the relief feature 1150 can be initially positioned at the proximal end of the staple cartridge 1122, and can be driven distally as the firing member 1154 advances the sled 1158 during a firing stroke, for example. In some instances, the firing member 1154 can drive the relief feature 1150 into engagement with the sled 1154 during the firing stroke. In certain instances, the relief feature 1150 can be coupled to the firing member 1154, for example. In other instances, the relief feature 1150 can be freely movable in the longitudinal slot 1152. For example, the relief feature 1150 can be positioned between the firing member 1154 and the sled 1158, however, the relief feature 1150 may not be coupled to either the firing member 1154 or the sled 1158, for example.

[0227] In various instances, the relief feature 1150 can be comprised of a flexible, deformable, and/or elastic material. For example, the relief feature 1150 can be comprised of a material having a lower durometer hardness than the firing member 1154 and/or the sled 1158. In such instances, the relief feature 1150 can be configured to at least partially absorb and/or accommodate distal translation and/or displacement of the firing member 1154. For example, the relief feature 1150 can act as a soft stop and/or brake. In such instances, the relief feature 1150 can initially slow and/or resist distal displacement of the firing member 1154. Moreover, if the firing member 1154 continues to be advanced distally, the relief feature 1150 can stop and/or prevent further distal displacement of the firing member 1154. As described herein, in various instances, the flexible firing bar 1118 can be advanced distally beyond the predefined distal-most position in the end effector 120 when the end effector 120 is only partially articulated and/or unarticulated. Moreover, when the end effector 120 is only partially articulated and/or unarticulated, the flexible firing bar 1118 can drive the sled 1158 distally into abutting contact with the distal end of the end effector 120 during a firing motion. In such instances, the relief feature 1150 can at least partially absorb the impact of a collision between the sled 1158 and the distal end of the end effector 120.

[0228] Referring still to the embodiment depicted in FIG. 22, the relief feature 1150 includes a tapered receptacle 1166, which can be configured to receive the distal end of the firing member 1154. In various instances, the tapered receptacle 1166 can define a pointed and/or narrowing shape. For example, the tapered receptacle 1166 can taper from a wider opening in the proximal region of the receptacle 1166 to a narrower opening at an intermediate region in the receptacle 1166. The distal region of the receptacle 1166 can be closed. In certain instances, the tapered receptacle 1166 can act as a brake, which can initially slow and/or resist distal displacement of the firing member 1154, and may ultimately stop and/or prevent further distal displacement of the firing member 1154, for example.

[0229] In various instances, the staple cartridge 1122 can comprise a tissue stop 1160 which can be aligned with the cutting edge 1156 of the firing member 1154. In various instances, the cutting edge 1156 can be configured to engage the cutting stop 1160, and can facilitate relief and/or absorption of energy during a firing stroke. In certain instances, the tissue stop 1160 can extend from the deck 1124 and overlie and/or obstruct at least a portion of the longitudinal slot 1152. In certain instances, the tissue stop 1160 can be comprised of a flexible, deformable, and/or elastic material. Additionally or alternatively, the tissue stop 1160 can be frangible. In still other instances, the tissue stop 1160 can act like a hard stop to prevent further distal displacement of the cutting edge 1156. The entire disclosure of U.S. patent application Ser. No. 14/512,637, entitled STAPLE CARTRIDGE, which was filed on Oct. 13, 2014 is incorporated by reference herein.

[0230] In certain instances, a firing bar stop can be incorporated into an end effector and/or a shaft of a surgical instrument. The firing bar stop can be configured to limit travel of a firing bar during a firing stroke. For example, a firing bar stop can include a catch or lockout positioned in the end effector and/or shaft that is structured and positioned to engage the flexible firing bar during the firing stroke. Such a lockout can engage the firing bar during a portion of the firing stroke to restrain and/or prevent further distal travel of the firing bar. In certain instances, the firing bar stop can be configured to shift relative to the shaft and/or the end effector when the end effector is moved to an articulated orientation relative to the shaft. The shifted position of the firing bar can depend on the degree in which the end effector has been articulated. As a result, the firing bar stop can engage and restrain the flexible firing bar at different positions relative to the shaft, and the position can be based on the degree in which the end effector has been articulated.

[0231] A firing bar stop 1658 is depicted in a surgical instrument 1600 illustrated in FIGS. 49-53. The surgical instrument 1600 can be similar in many respects to the surgical instrument 100 (FIG. 1). The surgical instrument 1600 includes an end effector 1620 rotatably coupled to a shaft 1610 about an articulation joint 1630. A staple cartridge 1622 (FIG. 49) can be positioned in the end effector 1620. During a firing stroke, a flexible firing bar 1618 is configured to move within the shaft 1610, the articulation joint 1630, and the end effector 1620 to advance a firing member 1654 (FIG. 49) distally. The firing member 1654 includes a cutting edge 1656 (FIG. 49). In certain instances, the firing member 1654 can advance a staple-deployment sled, which can fire staples from the staple cartridge 1622 and can move the staples into forming contact with an anvil 1624 (FIGS. 49, 51, and 53) of the end effector 1620.

[0232] For a given firing stroke length, the flexible firing bar 1618 will extend farther distally when the end effector 1620 is unarticulated compared to when the end effector 1620 is articulated, as described herein. Moreover, the distal-most position of the flexible firing bar 1618 will change as the articulation angle changes. Stated differently, for a given firing stroke length, the flexible firing bar 1618 will stop at a more proximal distal-most position when the end effector 1620 is articulated compared to when the end effector 1620 is unarticulated. Additionally, for a given firing stroke length, the flexible firing bar 1618 will stop at a more distal distal-most position when the end effector 1620 is less articulated compared to when the end effector 1620 is more articulated.

[0233] To ensure that the flexible firing bar 1618, staple-deploying sled, and/or cutting edge 1656 (FIG. 49) at least reach their intended distal-most positions within the end effector 1620 when the end effector 1620 is articulated, the firing stroke length can be selected such that the flexible firing bar 1618 travels distally to the desired distal-most position when the end effector 1620 is fully articulated. In such instances, to prevent the staple-deploying sled and/or other elements of the firing system from colliding with the distal end wall of the staple cartridge 1622 when the end effector 1620 is less than fully articulated, a firing bar stop, such as the firing bar stop 1658, for example, can be employed.

[0234] The firing bar stop 1658 can be configured to engage the flexible firing bar 1618 to restrain further distal displacement of the firing bar 1618 during a firing stroke. In certain instances, the firing bar stop 1658 can engage the flexible firing bar 1618 during a distal portion of the firing stoke. The firing bar stop 1658 can be configured to shift based on the degree in which the end effector 1620 is articulated. In other words, the firing bar stop 1658 can engage the flexible firing bar 1618 during different portions of the firing stroke depending on the degree in which the end effector 1620 has been articulated. The firing bar stop 1658 can form a relief member which accommodates for an overstroke of the flexible firing bar.

[0235] The firing bar stop 1658 can be configured to account for the change in distance to the desired distal-most position in the end effector 1620. More particularly, the firing bar stop 1658 can be configured to engage and restrain the flexible firing bar 1618 at a more distal position when the end effector 1620 is unarticulated, and can be configured to engage and restrain the flexible firing bar 1618 at a more proximal position when the end effector 1620 is articulated. In various instances, the firing stroke length can be selected such that the flexible firing bar 1618 reaches the desired distal-most positioned when the end effector 1620 is fully articulated. In such instances, the firing bar stop 1658 can be configured to prevent the staple-deploying sled and/or other elements of the firing system from colliding with the distal end wall of the staple cartridge 1622 when the end effector 1620 is less than fully articulated.

[0236] The firing bar stop 1658 depicted in FIGS. 49-53 includes a shiftable restraint 1660 and a catch 1662 on the flexible firing bar 1618. The catch 1662 defines a notch in the flexible firing bar 1618, and the shiftable restraint 1660 is configured to engage the catch 1662 during a portion of the firing stroke. For example, the shiftable restraint 1660 can move into abutting contact with the notch 1662 in the flexible firing bar 1618 as the flexible firing bar 1618 translates during the firing stroke. Abutment of the catch 1662 and the shiftable restraint 1660 is configured to prevent further distal displacement of the flexible firing bar 1618.

[0237] The firing bar stop 1658 also includes a plate 1670 engaged with the shiftable restraint 1660. The plate 1670 can define a geometry such that articulation of the plate 1670 is configured to shift the shiftable restraint 1660. For example, the plate 1670 includes a pair of lobes 1672 and a recess 1674 between the lobes 1672. The plate 1670 can be configured to move with the end effector 1620. Referring primarily to FIGS. 50 and 52, the plate 1620 can be secured to the end effector 1620 by at least one pin 1676, for example. As the end effector 1620 is moved to an articulated orientation relative to the shaft 1610, the plate 1670 can rotate with the end effector 1620. As a result, the plate 1670 can rotate relative to the shiftable restraint 1660 positioned within the shaft 1610 of the surgical instrument 1600.

[0238] When the end effector 1620 is in an unarticulated positioned (FIGS. 49-51), the recess 1764 of the plate 1670 can engage the shiftable restraint 1670. As a result, the shiftable restraint 1670 can be positioned in a distal position relative to the shaft 1610. A spring 1664 in the shaft 1610 can be configured to bias the shiftable restraint into the distal position. Moreover, when the end effector 1620 has been articulated and the plate 1670 has been rotated (FIGS. 52 and 53), a lobe 1672 of the plate 1670 can engage the shiftable restraint 1660. In such instances, the shiftable restraint 1660 can be positioned in a more proximal position relative to the shaft 1610. The spring 1664 is configured to deform to accommodate proximal shifting of the shiftable restraint 1660. As the end effector 1620 continues to articulate, the shiftable restraint 1660 can continue to shift proximally and the spring 1664 can be further compressed, for example. As the degree in which the end effector is articulated increases, the lobe 1672 of the plate 1670 can push the shiftable restraint 1660 farther in the proximal direction. In such instances, the position of the shiftable restraint 1660 can depend on the degree in which the end effector 1620 has been articulated.

[0239] When the shiftable restraint 1660 is in the distal position (FIGS. 49-51), the flexible firing bar 1618 can travel farther distally within the end effector 1620 before the catch 1662 moves into abutting contact with the shiftable restraint 1660. In various instances, the distal position of the shiftable restraint 1660 can be selected such that the flexible firing bar 1618 reaches the desired distal-most position in the end effector 1620 and avoids an end-of-stroke collision with the distal end of the staple cartridge 1622, for example. Moreover, when the shiftable restraint 1660 has been moved to a more proximal position (FIGS. 52 and 53), the catch 1662 can move into abutting contact with the shiftable restraint 1660 at a more proximal position. In various instances, proximal position(s) of the shiftable restraint 1660 can be selected based on the degree in which the end effector 1620 has been articulated such that the flexible firing bar 1618 reaches the desired distal-most position in the end effector 1620 when the end effector 1620 is in an articulated orientation. In the proximal position(s), the shiftable restraint 1660 can engage the catch 1663 and limit further distal displacement of the flexible firing bar 1618 before an end-of-stroke collision with the distal end of the staple cartridge 1622.

[0240] Referring now to FIG. 23, a fastener cartridge 1222 having a relief feature 1250 is depicted. The fastener cartridge 1222 can be similar in many respects to the fastener cartridge 122 (FIG. 1). For example, the fastener cartridge 1222 can be structured and dimensioned to replace the fastener cartridge 122 (FIG. 1) in the end effector 120 (FIG. 1). In certain instances, the fastener cartridge 1222 can include a cartridge body and a plurality of cavities can be defined in the cartridge body. Additionally, a plurality of fasteners, such as staples, for example, can be ejectably positioned in the cavities. The fastener cartridge 1222 is removably positioned in a cartridge channel 1282 which supports the fastener cartridge 1222 in the jaw of the end effector 120. The channel 1282 includes a longitudinal slot 1284 defined therein.

[0241] A firing member, such as the firing member 1154 (FIG. 22), for example, can be configured to traverse at least a portion of the longitudinal slot 1284 in the fastener cartridge 1222 to drive a sled or staple-deployment wedge, such as the sled 1158 (FIG. 22), for example. During a firing stroke, the firing member 1154 can fire fasteners from the fastener cartridge 1222 via the sled 1158 and/or drivers, for example, and can sever tissue adjacent to the cartridge 1222. Referring still to FIG. 23, the firing member can include a base or foot 1280. In various instances, the foot 1280 can be positioned to slide and/or move in a wider and/or t-shaped portion of the longitudinal slot 1284, for example.

[0242] In various instances, a soft stop or relief member 1250 can be positioned at least partially within and/or across the longitudinal slot 1284. For example, the relief member 1250 can block and/or obstruct a distal portion of the longitudinal slot 1284. In certain instances, the pathway of the foot 1280 of the firing member can be blocked by the relief member 1250. The relief member 1250 can be attached and/or integrally formed with the channel 1282, for example. In certain instances, the relief member 1250 can be welded and/or fastened to the channel 1282.

[0243] In various instances, the relief member 1250 can form a bridge across the longitudinal slot 1284. Referring to FIG. 23, the relief member 1250 includes a pair of arms 1251 and a central portion 1253. The arms 1251 are secured to the channel 1282 on opposite sides of the longitudinal slot 1284. Additionally, the central portion 1253 extends between the arms 1251, and at least a portion of the central portion 1253 is positioned in the longitudinal slot 1284.

[0244] The relief member 1250 depicted in FIG. 23 can be comprised of a flexible, deformable, and/or elastic material. For example, the relief feature 1250 can be comprised of a material having a lower durometer hardness than the foot 1280 and/or the channel 1282. In such instances, the relief feature 1250 can be configured to at least partially absorb and/or accommodate distal translation and/or displacement of the foot 1280 past the proximal edge of the relief feature 1250. For example, the relief feature 1250 can act as a soft stop and/or brake. In such instances, the relief feature 1250 can initially slow and/or resist distal displacement of the base 1280. Moreover, if the base 1280 continues to be advanced distally, the relief feature 1250 can stop and/or prevent further distal displacement of the firing member 1154.

[0245] Additionally or alternatively, the relief feature 1250 can be frangible. For example, the relief feature 1250 can be designed and/or structured to break when the base 1280 is advanced distally into and/or past the relief feature 1250. In certain instances, the relief feature 1250 can slow and/or absorb at least a portion of the force of the foot 1280 prior to breaking.

[0246] As described herein, stroke length relief features in a staple cartridge, end effector and/or shaft of a surgical instrument can be configured to deform, compress, and/or break to absorb at least a portion of the firing force and/or to stop further advancement of the firing member during a firing stroke. In other instances, a relief feature can include a predefined pathway, channel and/or opening in the staple cartridge. Such a relief feature can accommodate an overstroke of the firing member. An overstroke of the firing member can occur when the firing stroke of the firing member is not adjusted to account for the degree in which the end effector 120 has been articulated, for example.

[0247] Referring now to FIG. 24, a fastener cartridge 1322 including a relief feature 1350 is depicted. In many respects, the fastener cartridge 1322 can be similar to the fastener cartridge 122 (FIG. 1). For example, the fastener cartridge 1322 can be structured and dimensioned to replace the fastener cartridge 122 (FIG. 1) in the end effector 120 (FIG. 1). In certain instances, the fastener cartridge 1322 can include a cartridge body 1324 and a plurality of cavities 1326 can be defined in the cartridge body 1324. Additionally, a plurality of fasteners, such as staples, for example, can be ejectably positioned in the cavities 1326.

[0248] A firing member, such as the firing member 1154 (FIG. 22), for example, can be configured to traverse at least a portion of the cartridge body 1324 to drive a sled or staple-deployment wedge 1358, for example. Such a firing member can also include a base or foot, such as foot 1380, for example. During a firing stroke, the firing member can fire fasteners from the fastener cartridge 1322 via the sled 1358 and/or drivers, for example, and can sever tissue adjacent to the cartridge 1322.

[0249] The relief feature 1350 depicted in FIG. 24 includes an opening 1352 defined through the distal end of the cartridge 1322. For example, the opening 1352 can form a distal aperture through the distal wall of the staple cartridge 1322. In the depicted embodiment, the relief feature 1350 includes a plurality of openings 1352. The openings 1352 extend through the distal end of the cartridge 1322 and provide a pathway and/or clearance for at least a portion of the sled 1358 to protrude through the distal end. For example, when the end effector 120 (FIG. 1) is partially articulated or unarticulated, the sled 1358 can be advanced distally into abutting contact with the distal end of the cartridge 1322. To permit continued distal travel of the sled 1358, the openings 1352 can be sized and dimensioned to receive the distal-most portion(s) of the sled 1358.

[0250] As described herein, the articulation of an end effector can affect the firing path of a flexible firing bar in the shaft and/or the end effector of a surgical instrument. Moreover, the articulation of an end effector can change the distal-most position of a firing element during a firing stroke. In various instances, a controller can adjust the firing stroke length of the firing bar such that the firing element is stopped at the same spot regardless of the articulation angle of the end effector. In other instances, an end effector and/or firing system can include a relief member configured to absorb and/or accommodate changes in the distal-most position of the firing element.

[0251] In various instances, the firing stroke, e.g., the distance traveled by the firing rod 114 (see, e.g., FIGS. 1 and 3), can be selected such that the staple-deploying sled 1358 still reaches the distal end of the staple cartridge 1322 even when the end effector 120 (FIG. 1) is fully articulated. In such instances, the sled 1358 can continue to translate distally and fire staples from the distal-most staple cavities 1326. As a result, the firing stroke can extend beyond the distal end of the staple cartridge 1322 when the end effector 120 is less than fully articulated, e.g., partially articulated and/or unarticulated. Without a relief feature, such as the apertures 1352, for example, the sled 1358 would collide with the distal end of the staple cartridge 1322. The relief feature can prevent and/or minimize damage to elements of the firing system and/or a motor, for example, when the end effector is less than fully articulated.

[0252] In certain instances, the distal-most position of the firing element may be shifted proximally when the end effector is in an articulated orientation. For example, a component of the firing system, such as a flexible firing bar, for example, may be inclined to bow outward when the end effector is in an articulated orientation. In such instances, outward bowing of the flexible firing beam may shift the distal-most position of the firing element proximally, thereby resulting in a need for a longer firing stroke of the firing bar when the end effector has been articulated.

[0253] A fastener cartridge 1422 is depicted in FIG. 25. The fastener cartridge 1422 can be similar to the fastener cartridge 122 (FIG. 1) in many respects. For example, the fastener cartridge 1422 can be structured and dimensioned to replace the fastener cartridge 122 (FIG. 1) in the end effector 120 (FIG. 1). In certain instances, the fastener cartridge 1422 can include a cartridge body and a plurality of cavities can be defined in the cartridge body. Additionally, a plurality of fasteners, such as staples, for example, can be ejectably positioned in the cavities. The fastener cartridge 1422 depicted in FIG. 25 further includes an elongate channel 1482 positioned at least partially around the cartridge body. The depicted channel 1482 includes a longitudinal slot 1484 extending at least partially therethrough.

[0254] Referring still to FIG. 25, a flexible firing bar 1418 can be configured to transfer a firing motion to a firing member, such as the firing member 1154 (FIG. 22), for example. The flexible firing bar 1418 can be configured to traverse at least a portion of the longitudinal slot 1484 in the fastener cartridge 1422 to drive a firing element, such as the firing member 1154, for example, and/or a staple-deployment sled, such as the sled 1158 (FIG. 22), for example. During a firing stroke, the firing member can fire fasteners from the fastener cartridge 1422 via the sled and/or drivers, for example, and can sever tissue adjacent to the cartridge 1422.

[0255] In the depicted embodiment of FIG. 25, the firing member includes a base or foot 1480. In various instances, the foot 1480 can be configured to slide and/or move along at least a portion of the longitudinal slot 1484. In various instances, the longitudinal slot 1484 can be t-shaped and/or can have a wider portion adjacent to the outer surface of the channel 1482. In certain instances, the engagement between the foot 1480 and slot 1484 can be configured to guide and/or hold the firing element in the end effector.

[0256] The depicted fastener cartridge 1422 includes a distal stop 1450. Referring to the embodiment depicted in FIG. 25, the distal stop 1450 is positioned at the distal end of the longitudinal slot 1484. For example, the distal end of the longitudinal slot 1484 can form the distal stop 1450. In various instances, the distal stop 1450 can restrain and/or prevent further distal displacement of the foot 1480 in the staple cartridge 1422 and, thus, restrain and/or prevent further distal displacement of the firing member in the staple cartridge 1422.

[0257] Referring to the embodiment depicted in FIG. 25, the distal stop 1450 includes a stepped profile at the distal end of the longitudinal slot 1484. For example, the depicted distal stop 1450 includes a plurality of steps, including a first step 1451, a second step 1452, and a third step 1453. The steps 1451, 1452, 1452 of the distal stop 1450 are positioned and structured to receive and/or restrain the foot 1480 of the firing member when the end effector is oriented at different degrees of articulation. For example, for a given firing stroke, the firing member may stop at different end-of-stroke positions within the staple cartridge, depending on the degree in which the end effector has been articulated. For instance, the firing bar will travel further into the staple cartridge for a given firing stroke when the end effector is unarticulated as compared to when the end effector is articulated. The foot 1480 can be driven distally to the first step 1451 when the end effector is unarticulated, which is the distal-most step. Accordingly, the foot 1480 can be permitted to translate to the distal-most position when the end effector is unarticulated. Referring still to FIG. 25, when the end effector is unarticulated, the flexible firing bar 1418 can be aligned with the longitudinal slot 1484 and the first step 1451, which can be centrally-positioned in the distal stop 1450. In such instances, the flexible firing bar 1418 can extend along a longitudinal path which results in shortest distance between the proximal end of the staple cartridge and the distal-most position of the foot 1480.

[0258] Referring now to the staple cartridge 1422′ depicted in FIG. 25, which corresponds to the staple cartridge 1422 when the end effector is in an articulated orientation, the articulation of the end effector 120 (FIG. 1) can affect bowing and/or bending of the flexible firing bar 1418. In such instances, the flexible firing bar 1418 begins its firing stroke further away from the distal end of the staple cartridge as compared to when the end effector is in an unarticulated orientation. Additionally or alternatively, the firing element and foot 1480 thereof can be biased laterally outboard and/or away from the centerline of the staple cartridge 1422. Because the distance to the distal-most step 1451 is altered when the end effector is articulated and/or the flexible firing bar 1418 bows and/or bends, the foot 1480 may not extend as far distally in the staple cartridge 1422′ during a firing stroke as compared to when the end effector 120 has not been articulated.

[0259] Referring still to the staple cartridge 1422′, the foot 1480 can extend distally to the third step 1453 which is positioned proximal to the first step 1451, when the end effector has been articulated. The third step 1453 is the proximal-most step. Accordingly, when the end effector is articulated, translation of the foot 1480 can be stopped and/or otherwise restrained at a more proximal position than when the end effector 120 (FIGS. 1 and 2) is in an unarticulated orientation. Additionally or alternatively, the step(s) associated with the articulated orientation(s) of the end effector, e.g., the second step 1452 and the third step 1453, can be positioned laterally outboard and/or away from the centerline of the staple cartridge 1422.

[0260] In the depicted embodiment, the foot 1480 is restrained by the proximal-most step 1453 when the end effector is articulated 75°, for example. In other instances, the foot 1480 may be restrained by the proximal-most step 1453 when the end effector is articulated less than or more than 75°. Moreover, in other instances, the distal stop 1450 can include an suitable number of steps. In some instances, the distal stop 1450 can include two steps, for example.

[0261] In certain instances, the distal stop 1450 can comprise a hard stop, which can abruptly brake and/or stop the distal progression of the foot 1480. In other instances, a hard stop can be proximal to the articulation joint as disclosed in U.S. Pat. No. 7,658,311, entitled SURGICAL STAPLING INSTRUMENT WITH A GEARED RETURN MECHANISM, which issued on Feb. 9, 2010, the entire disclosure of which is hereby incorporated by reference herein. In still other instances, the distal stop 1450 can comprise a soft stop, which can initially slow the distal progression of the foot 1480 and may ultimately stop the distal progression of the foot 1480. In at least one instance, the distal stop 1450 can be comprised of a flexible, deformable, and/or elastic material. Additionally or alternatively, the distal stop 1450 can be frangible and can be configured to break when a predefined force is applied thereto, for example.

[0262] As described herein, the articulation of a surgical end effector can affect the distal-most position of a flexible firing bar, a cutting element, and/or a wedge sled, for example. In certain instances, when the end effector is moved to an articulated orientation, the flexible firing bar, the cutting element, and/or the wedge sled can stop at a position that is proximal to the distal-most position when the end effector is unarticulated. In such instances, the arc and/or curvature of the flexible firing bar and firing path thereof can effectively shorten the firing stroke. In certain instances, as discussed above, the firing stroke length can be adjusted to take into account the articulation of the end effector. In some instances, the surgical instrument can include a relief feature that is configured to absorb and/or other accommodate at least a portion of the firing stroke.

[0263] In still other instances, the firing path of the flexible firing bar can be adjusted to account for the articulation of the end effector and effective change in the firing stroke length. For example, the flexible firing bar can be biased and/or guided along a firing path that defines a shorter distance to the distal-most position in the end effector. In certain instances, the adjusted firing path can inhibit and/or resist outward bowing of the flexible firing bar and/or can urge inward shifting and/or bending of the flexible firing bar, for example.

[0264] Referring now to FIGS. 26 and 27, a surgical instrument 1500 is depicted. Similar to the surgical instrument 100, the surgical instrument 1500 includes an end effector 1520 that is configured to clamp, fasten, and/or incise tissue. The surgical instrument 1500 also includes a shaft 1510 and an articulation joint 1530 positioned intermediate the shaft 1510 and the end effector 1520. Similar to the flexible firing bar 118, a flexible firing bar 1518 can receive a firing motion from a firing rod, such as the firing rod 114 (FIGS. 1 and 3-5), for example, and transfer the firing motion to the end effector 1520. The flexible firing bar 118 can be operably coupled to a cutting element, such as the firing member 1154 and the cutting edge 1156 (FIG. 22), for example, and/or can drive a wedge sled, such as the sled 1158 (FIG. 22), for example.

[0265] In various instances, the shaft 1510 can include an attachment portion 1512, which is rotatably and/or pivotably connected to the end effector 1520. For example, referring still to FIGS. 26 and 27, the attachment portion 1512 can be coupled to the proximal end of an elongate channel that is structured and dimensioned to receive a fastener cartridge. The end effector 1520 can be configured to articulate relative to the shaft 1510 about the attachment portion 1512. For example, the elongate channel can move and/or pivot on the attachment portion 1512 of the shaft 1510.

[0266] A firing path modifier or shifter 1550 is also depicted in FIGS. 26 and 27. The firing path modifier 1550 can be configured to adjust the firing path of the flexible firing bar 1518. In the depicted embodiment, the firing path modifier 1550 is positioned in the articulation joint 1530. The firing path modifier 1550 includes an arcuate or arched slot 1552 and a yoke or linked pin assembly 1554. Referring still to FIGS. 26 and 27, the yoke 1554 includes a first pin or end 1556 and a second pin or end 1558, which are positioned in the arcuate slot 1552. The pins 1556 and 1558 are separated by a fixed distance. In various instances, the yoke 1554 can move relative to the arcuate slot 1552. For example, the pins 1556, 1558 can move, slide, and/or float within the slot 1552.

[0267] Referring still to FIGS. 26 and 27, a portion of the flexible firing bar 1518 can be positioned between the first pin 1556 and the second pin 1558. In such instances, the yoke 1554 can guide the flexible firing bar 1518. Moreover, because movement of the yoke 1554 is restrained by the arcuate slot 1552, the shifter 1550 can adjust the firing path and/or bias the flexible firing bar 1518 toward a modified firing path.

[0268] When the end effector 1550 is unarticulated as depicted in FIG. 26, the flexible firing bar 1518 can extend along a firing path that is collinear with the longitudinal axis L of the shaft 1510 and the end effector 1520. In such instances, the geometry of the arcuate slot 1552 can be configured to maintain the longitudinal alignment of the firing path and the longitudinal axis L. An inflection point of the arced slot 1152 can be aligned with the longitudinal axis L wherein the first pin 1556 is positioned in the slot 1152 on a first side of the longitudinal axis L and the second pin 1558 is positioned in the slot 1152 on a second side of the longitudinal axis L. As a result, the yoke 1554 can guide and/or maintain the flexible firing bar 1518 into alignment with the longitudinal axis L.

[0269] When the end effector 1520 is moved to an articulated orientation relative to the shaft 1510, referring now to FIG. 27, the shifter 1550 can shift and/or bias the flexible firing bar 1518 along a shorter firing path. The yoke 1554 can shift laterally in the arcuate slot 1552. For example, the flexible firing bar 1518 can pull the yoke 1554 inward as the flexible firing bar 1518 bends. Additionally, the yoke 1554 can guide the flexible firing bar 1518 because the yoke 1554 is restrained by the slot 1552. As depicted in FIG. 27, the yoke 1554 can shift out of alignment with the longitudinal axis L₁ of the shaft 1510. In such instances, the firing path can be modified such that the inner corner or turn of the firing path at the articulation point is replaced with a more direct and/or chamfered path. Because the shifter 1550 effectively shortens the firing path, the effect on the end-of-stroke position of the flexible firing bar 1518 as a result of the degree in which the end effector 1520 has been articulated can be reduced. Stated differently, the shifter 1550 can at least partially negate the effective change in firing stroke length due to an articulation motion.

[0270] Referring primarily to FIG. 27, when the end effector is articulated, the yoke 1554 can shift laterally in the arcuate slot 1552. Though the flexible firing bar 1518 can experience a torque and/or outward bowing force, the shifter 1550 can resist the torque and/or outward bowing force. For example, the bearing load on the sidewalls of the arcuate slot 1552 can generate a frictional force which can resist torqueing and/or bowing of the flexible firing bar 1518.

[0271] An end effector assembly 3100 is depicted in FIGS. 28-30. The end effector assembly 3100 comprises a first jaw 3110 and a second jaw 3120. The first jaw 3110 comprises a staple cartridge 3112 including a plurality of staples removably stored therein. The plurality of staples are deployed from the staple cartridge 3112 by a firing assembly 3150. The second jaw 3120 comprises an anvil 3122 configured to deform the staples when they are ejected from the staple cartridge 3112. The firing assembly 3150 is configured to travel between a proximal end 3101 of the end effector and a distal end 3102. The firing assembly 3150 comprises a sled 3151 configured to deploy the staples, a cutting member 3152 configured to incise tissue during the longitudinal progression of the firing assembly 3150, and a firing member 3153 configured to push the sled 3151 and/or the cutting member 3152 distally through the end effector assembly 3100. The firing member 3153 is configured to slide within a longitudinal slot 3111 defined in the staple cartridge 3112. The sled 3151, cutting member 3152, and/or firing member 3153 can include a first cam 3158 configured to engage the first jaw 3110 and a second cam 3159 configured to engage the second jaw 3120 as the firing assembly 3150 is advanced distally. The first cam 3158 and the second cam 3159 can co-operate to position the anvil 3122 relative to the staple cartridge 3112 and define a tissue gap therebetween. The firing member 3153 can be actuated by a surgical instrument assembly which can comprise a handle actuatable by a clinician and/or a robotically operated actuator, for example.

[0272] Various embodiments discussed herein utilize changes in electrical resistance, capacitance, and/or inductance within an electrical circuit to determine the location of a firing assembly within an end effector. By sensing the change in electrical resistance within a circuit that occurs due to the movement of the firing assembly through the end effector, for example, the position of the firing assembly can be determined. Referring to FIG. 27, the end effector assembly 3100 comprises a plurality of resistive elements 3105. The resistive elements 3105 are arranged longitudinally within the first jaw 3110. The resistive elements 3105 are positioned in the longitudinal slot 3111 defined in the staple cartridge 3112; however, the resistive elements 3105 can be arranged in any suitable manner in which the firing assembly 3150 can contact the resistive elements 3105. The resistive elements 3105 are arranged in parallel circuit segments in a firing progress detection circuit. In at least one instance, each resistive element 3105 is in communication with a first common electrical path which is in communication with a microprocessor of the firing progress detection circuit. In various instances, the first common electrical path can extend through the staple cartridge 3112, for example. As described in greater detail further below, the electrical firing progress detection circuit is completed, or at least partially completed, by the firing assembly 3150 as the firing assembly 3150 is advanced distally.

[0273] Portions of the firing assembly 3150 can be conductive for the purpose of providing a second electrical path between the resistive elements 3105 and the microprocessor of the firing progress detection circuit. In at least one such instance, the second electrical path can extend through the firing member 3153, for example. In other instances, the second electrical path can extend through the second jaw 3120. As the firing assembly 3150 progresses through the end effector 3100 toward the distal end 3102, the parallel circuit segments including the resistive elements 3105 are sequentially closed by the firing assembly 3150 and, as a result, the resistive elements 3105 are sequentially added to the electrical path experienced by the firing assembly 3150. When the resistive elements 3105 are added to the electrical path created by the firing assembly 3150, the electrical resistance of the firing progress detection circuit increases. This change in electrical resistance can be detected by measuring the resistance and/or voltage drop between the first electrical path and the second electrical path. The resistance measured can be related to the distance traveled by the firing assembly 3150. The resistance of the firing progress detection circuit will increase as the firing assembly 3150 is advanced distally. Correspondingly, the resistance of the firing progress detection circuit will decrease as the firing member 3150 is retracted proximally.

[0274] The resistive elements 3105 provide discrete increases in resistance to the firing progress detection circuit when the parallel circuit segments including the resistive elements 3105 are contacted and closed by the firing assembly 3150. In various instances, further to the above, a parallel circuit segment can remain closed as the firing assembly 3150 is advanced distally. Thus, a first parallel circuit segment can be closed by the firing assembly 3150 and remain closed as the firing assembly 3150 closes a second parallel circuit segment and a third parallel circuit segment and so forth. The closure of the parallel circuit segments can demark waypoints during the firing progression of the firing member. The combination of the closed parallel circuit segments can provide the firing progress detection circuit with a unique and identifiable resistance that corresponds to a specific position, or range of positions, of the firing assembly 3150. In other instances, a parallel circuit segment can be closed by the firing assembly 3150 and then re-opened as the firing assembly 3150 is advanced distally thereby. Such an arrangement can provide a momentary pulse to the microprocessor indicating that the firing assembly 3150 has reached a waypoint. In at least one such instance, the parallel circuit segments can each have different resistances thereby providing the firing progress detection circuit with a unique and identifiable resistance that corresponds to a specific position, or range of positions, of the firing assembly 3150. For instance, a first parallel circuit segment can have a first resistance and a second parallel circuit segment can have a second resistance which is different than the first resistance, and so forth.

[0275] In addition to the resistive elements 3105, or as an alternative, the firing progress detection circuit can include a potentiometer, for example, configured to track the firing progress of the firing assembly 3150. In such instances, the resistance of the firing progress detection circuit can increase continuously as the firing member 3150 is advanced distally. Correspondingly, the resistance of the firing progress detection circuit can decrease continuously as the firing member 3150 is retracted proximally. A continuous change in resistance can be provided by a longitudinal resistive member positioned within the first jaw 3110 and/or the second jaw 3120. The firing assembly 3150 is configured to contact the longitudinal resistive member along the length of the end effector 3100. The resistance experienced by the firing assembly may vary linearly as the firing assembly 3150 progresses through the end effector 3100. As the firing member 3153 progresses distally, the total length of the resistive member in contact with the firing assembly 3150 increases. The increase in length changes the electrical resistance of the firing progress detection circuit which can be detected and evaluated by the microprocessor. In various instances, measuring the change in resistance of the firing progress detection circuit can provide position, velocity, and/or acceleration feedback of the firing assembly 3150.

[0276] Referring to FIG. 30, an elongate channel 3160 of the first jaw 3110 is configured to support a staple cartridge, such as the staple cartridge 3122, for example, in accordance with various embodiments. The elongate channel 3160 comprises a slot 3161 configured to at least partially receive the firing member assembly 3150 discussed above. The slot 3160 comprises a distal end 3162. The distal end 3162 of the slot 3160 can receive the firing member assembly 3150 when the firing member assembly 3150 reaches its end of stroke position. Once the firing member assembly 3150 reaches the distal end 3162 of the slot 3161, the firing member assembly 3150 may bottom out.

[0277] Further to the above, the surgical instrument can comprise a control system including a microprocessor configured to detect when the firing member assembly 3150 has bottomed out in the end effector 3100. In at least one instance, the firing member assembly 3150 can be driven by an electric motor and the microprocessor can be configured to monitor the power draw of the electric motor. In at least one such instance, the microprocessor can monitor the current drawn by the electric motor, for example. When the control system detects an increase in the power drawn by the electric motor sufficient to indicate that the firing member assembly 3150 has bottomed out, the control system can interrupt the power supply to the electric motor and/or reverse the polarity of the voltage applied to the firing member assembly 3150. In addition to or in lieu of the above, the end effector assembly 3100 can include a sensor, such as sensor 3106, for example, which can detect when the firing member assembly 3150 has reached the end of its firing stroke. The sensor 3106 can comprise a proximity sensor and/or a Hall Effect sensor, for example. In any event, the control system can include means for generating haptic feedback in the handle of the surgical instrument to indicate to the user of the surgical instrument that the firing member assembly 3150 has reached the end of its firing stroke. In various instances, the haptic feedback can be generated by an electric motor comprising an imbalanced rotor, for example. By positioning the bottom out location 3162 distal to the articulation joint 3130, the furthest position that the firing assembly 3150 may travel is linked to the distal end 3102 of the end effector 3100, regardless of the angle in which the articulation joint 3130 is articulated.

[0278] An end effector assembly 3200 is depicted in FIGS. 31-33. The end effector assembly 3200 comprises a first jaw 3210 and a second jaw 3220. The first jaw 3210 comprises a staple cartridge 3212 including a plurality of staples removably stored therein. The plurality of staples can be deployed from the staple cartridge 3212 by a firing assembly 3250. The second jaw 3220 comprises an anvil 3222 configured to deform the staples when they are ejected from the staple cartridge 3212. The firing assembly 3250 is configured to travel between a proximal end 3201 of the end effector and a distal end 3202. The firing assembly 3250 comprises a sled 3251 configured to deploy the staples, a cutting member 3252 configured to incise tissue during the longitudinal progression of the firing assembly 3250, and a firing member 3253 configured to push the sled 3251 and/or the cutting member 3252 distally through the end effector assembly 3200. The firing member 3253 can be actuated by a handle actuatable by a clinician and/or a robotically operated actuator, for example.

[0279] The end effector assembly 3200 further comprises a distal sensor 3224b and a proximal sensor 3254a. The distal sensor 3224b is configured to detect the position of the second jaw 3220 and/or the position of the firing assembly 3250. The proximal sensor 3254a is configured to detect the position of the firing assembly 3250. The distal sensor 3224b and the proximal sensor 3254a comprise Hall Effect sensors, for example. The distal sensor 3224b is positioned at the distal end 3202 of the end effector 3200 on the second jaw 3220. The proximal sensor 3254a is positioned on the firing assembly 3250 and is configured to travel between the proximal end 3201 of the end effector 3200 and the distal end 3202 in conjunction with the firing assembly 3250. The staple cartridge 3212 further comprises a distal detectable element 3214b and a proximal detectable element 3214a. The detectable elements 3214a, 3214b may be at least partially comprised of a ferrous material, for example. In various instances, the detectable elements 3214a, 3214b can comprise permanent magnets and/or electromagnets, for example. In any event, the detectable elements 3214a, 3214b are detectable by the sensors 3254a, 3224b. The proximal detectable element 3214a is positioned within the staple cartridge 3212 at the proximal end 3201 of the end effector 3200, for example. The distal detectable element 3214b is positioned within the staple cartridge 3212 at the distal end 3202 of the end effector 3200, for example.

[0280] When the staple cartridge 3212 is positioned in the end effector 3200, the detectable elements 3214a, 3214b of the staple cartridge 3212 may provide the sensors 3254a, 3224b of the surgical instrument with an initial signal configuration. The initial signal configuration may be communicated to a microprocessor of the surgical instrument control system immediately following the installation of the staple cartridge 3212 into the end effector 3200. In various instances, the surgical instrument can include a cartridge presence sensor configured to detect whether a staple cartridge has been positioned in the end effector 3200. The cartridge presence sensor is also in signal communication with the microprocessor of the control system. When the microprocessor determines that a staple cartridge is not positioned in the end effector 3200, the microprocessor may not perform a signal evaluation of the sensors 3254a, 3224b, and when the microprocessor determines that a staple cartridge is positioned in the end effector 3200, the microprocessor can perform an initial signal evaluation of the sensors 3254a, 3224b.

[0281] As part of performing an initial signal evaluation of the sensors 3254a, 3224b, the microprocessor can identify the type of staple cartridge 3212 positioned in the end effector 3200. More specifically, each type of staple cartridge that can be used with the end effector 3200 can comprise a unique arrangement of the detectable elements 3214a and/or 3214b which can create a unique magnetic field array which is detectable by the sensors 3254a and/or 3224b and identifiable by the microprocessor of the control system. For example, the detectable element 3214a may generate a first magnetic field intensity for a first type of staple cartridge and a second magnetic field intensity for a second type of staple cartridge, and so forth, which can be detected by the sensor 3254a during the initial evaluation of the sensor signals. In various instances, the firing system 3250 can be held in a predetermined, or datum, position during the initial evaluation of the sensor signals such that the staple cartridge positioned in the end effector 3200 can be reliably identified. In any event, the microprocessor can access a lookup table and, using the value of the magnetic field intensity detected during the initial signal evaluation, determine the correct operating program for the surgical instrument to properly fire the staple cartridge positioned in the end effector 3200. The lookup table can be stored in virtual memory and/or physical memory. Such memory may be accessible by and/or integral with the microprocessor.

[0282] The position of the second jaw 3220 can be monitored to determine if the second jaw 3220 is in a position to deform the staples when the staples are ejected from the staple cartridge 3212. The distal detectable element 3214b is positioned such that the signal detected by the distal sensor 3224b is related to the position of the second jaw 3220 relative to the first jaw 3210. Stated another way, the distance between the distal sensor 3224b and the distal detectable element 3214b affects the magnitude of the magnetic field detected by the distal sensor 3224b. When the second jaw 3220 is in an open position, the distal sensor 3224b will detect a first intensity of the magnetic field produced by the distal detectable element 3214b. When the second jaw 3220 is in a fully-closed position, the distal sensor 3224b will detect a second intensity of the magnetic field produced by the distal detectable element 3214b. As the reader will appreciate, the second intensity detected by the distal sensor 3224b is larger than the first field intensity because the distal sensor 3224b is closer to the distal detectable element 3214b when the second jaw 3220 is in its fully-closed position.

[0283] Further to the above, the intensity of the magnetic field detected by the distal sensor 3224b can be utilized by the microprocessor to determine the position of the second jaw 3220 relative to the first jaw 3210. If the microprocessor determines that the second jaw 3220 has not been sufficiently closed to properly form the staples when they are ejected from the staple cartridge 3212, the microprocessor can prevent the distal advancement of the firing system 3250. In at least one such instance, the microprocessor may not permit power to be supplied to the electric motor configured to drive the firing system 3250. If the microprocessor determines that the second jaw 3220 has been sufficiently closed to properly form the staples when they are ejected from the staple cartridge 3212, the microprocessor can advance the firing system 3250 distally when commanded to do so by a firing actuator operated by the user of the surgical instrument, for example. In various instances, the microprocessor may prevent the firing system 3250 from being advanced distally when the magnetic field intensity detected by the distal sensor 3224b is in a first range and, correspondingly, permit the firing system 3250 to be advanced distally when the magnetic field intensity detected by the distal sensor 3224b is in a second range.

[0284] In addition to or in lieu of the above, the position of the firing system 3250 can be monitored by the proximal sensor 3254a and/or the distal sensor 3224b as the firing system 3250 progresses from the proximal end 3201 of the end effector 3200 to the distal end 3202. When the firing system 3250 is in its unfired position, referring to FIG. 31, the proximal sensor 3254a is positioned adjacent to, but proximally with respect to, the proximal detectable element 3214a. In such a position, the proximal sensor 3254a can detect a first magnetic field created by the proximal detectable element 3214a. As the firing system 3250 is moved distally, the firing system 3250 moves closer to the proximal detectable element 3214a and, as a result, the magnitude of the first magnetic field detected by the proximal sensor 3254a increases. Once the firing system 3250 passes the proximal detectable element 3214a, referring to FIG. 32, the magnitude of the first magnetic field detected by the proximal sensor 3254a decreases. In various instances, the proximal sensor 3254a and the proximal detectable element 3214a can be aligned along a longitudinal axis and the magnitude of the first magnetic field detected by the proximal sensor 3254a is inversely proportional to the square of the distance between the proximal sensor 3254a and the proximal detectable element 3214a. In at least one such instance, the proximal detectable element 3214a can be aligned with the path of the proximal sensor 3254a. In other instances, the proximal detectable element 3214a can be offset with respect to the path of the proximal sensor 3254a.

[0285] As discussed above, the proximal sensor 3254a is in signal communication with a microprocessor of the surgical instrument control system. Further to the above, the microprocessor can access another lookup table and, using the value of the first magnetic field intensity detected by the proximal sensor 3254a, assess the position of the firing system 3250 positioned in the end effector 3200. Similar to the above, the lookup table can be stored in virtual memory and/or physical memory. Such memory may be accessible by and/or integral with the microprocessor. In at least one instance, the lookup table can comprise an array of magnetic field values which are arranged in a sequential order which corresponds to the distal progression of the firing system 3250. The microprocessor can compare the magnitude of the first magnetic field intensity detected by the proximal sensor 3254a and compare that value to the array of values in the lookup table. In some instances, the microprocessor can compare the current, or most-recently acquired, value to the array in addition to comparing one or more previously-obtained values to the array. The lookup table can further include an array of position values which is linked to the array of magnetic field intensity values and can indicate the position of the firing system 3250 to the microprocessor.

[0286] As the firing system 3250 is advanced distally, referring to FIG. 33 the firing system 3250 can approach the distal detectable element 3214b. Similar to the above, the proximal sensor 3254a can detect a second magnetic field created by the distal detectable element 3214b. As the firing system 3250 is moved distally, the firing system 3250 moves closer to the distal detectable element 3214b and, as a result, the magnitude of the second magnetic field detected by the proximal sensor 3254a increases. The distal detectable element 3214b is positioned distally with respect to the proximal sensor 3254a throughout the firing stroke of the firing system 3250. In other embodiments, the proximal sensor 3254a can pass the distal detectable element 3214b during the firing stroke of the firing system 3250. When the firing system 3250 passes the distal detectable element 3214b, in such circumstances, the magnitude of the second magnetic field detected by the proximal sensor 3254a decreases. In various instances, the proximal sensor 3254a and the distal detectable element 3214b can be aligned along a longitudinal axis and the magnitude of the second magnetic field detected by the proximal sensor 3254a is inversely proportional to the square of the distance between the proximal sensor 3254a and the distal detectable element 3214b. In at least one such instance, the distal detectable element 3214b can be aligned with the path of the proximal sensor 3254a. In other instances, the distal detectable element 3214b can be offset with respect to the path of the proximal sensor 3254a.

[0287] As outlined above, the proximal sensor 3254a can be configured to detect the magnetic field generated by the proximal detectable element 3214a to determine the position of the firing system 3250. Alternatively, the proximal sensor 3254a can be configured to detect the magnetic field generated by the distal detectable element 3214b to determine the position of the firing system 3250. Such alternatives are possible when only one of the detectable elements 3214a, 3214b are emitting a magnetic field during the firing stroke of the firing system 3250. In at least one such embodiment, at least one of the detectable elements 3214a, 3214b can comprise an electromagnet which can be deactivated during the firing stroke of the firing system 3250 such that the electromagnet is no longer producing a sufficiently detectable magnetic field. In various instances, however, both detectable elements 3214a, 3214b produce a magnetic field during the firing stroke of the firing system 3250, especially when the detectable elements 3214a, 3214b comprise permanent magnets, for example. In such instances, the proximal sensor 3254a may detect the first magnetic field produced by the proximal detectable element 3214a and the second magnetic field produced by the distal detectable element 3214b at the same time. Thus, the overall magnetic field detected by the proximal sensor 3254a from the first magnetic field and the second magnetic field can be evaluated and compared to an array of magnetic field values that takes the combined magnetic field into account.

[0288] An end effector assembly 3300 is depicted in FIGS. 34-41. The end effector assembly 3300 comprises a first jaw 3310 and a second jaw 3320. The first jaw 3310 comprises a staple cartridge 3312 which includes a plurality of staples removably stored therein. The plurality of staples can be deployed from the staple cartridge 3312 by a firing assembly 3350. The second jaw 3320 comprises an anvil 3322 configured to deform the staples when they are ejected from the staple cartridge 3312. The firing assembly 3350 is configured to travel between a proximal end 3301 of the end effector and a distal end 3302. The firing assembly 3350 comprises a sled 3351 configured to deploy the staples, a cutting member 3352 configured to incise tissue during the longitudinal progression of the firing assembly 3350, and a firing member 3253 configured to push the sled 3351 and/or the cutting member 3352 distally through the end effector assembly 3300. The firing member 3353 can be actuated by a surgical instrument assembly comprising a shaft 3340 and an articulation joint 3330 which is configured to permit the end effector assembly 3300 to be articulated relative to the shaft 3340. The firing member 3353 is positioned in the shaft 3340 such that, when the firing member 3353 is actuated, the firing member 3353 travels longitudinally within the shaft 3340 to fire the staples in the staple cartridge 3312. Further to the above, the firing member 3353 can extend through the articulation joint 3330 and can bend within the articulation joint 3330 when the end effector 3300 is articulated. The surgical instrument assembly can further comprise a handle actuatable by a clinician and/or a robotically operated actuator, for example, to move the firing member 3353 relative to the end effector 3300.

[0289] The proximal end of the end effector 3300 comprises a channel retainer 3360. The channel retainer 3360, shown in FIG. 35, comprises a drive post 3365 extending therefrom which can be pushed distally and/or pulled proximally by an articulation actuator 3366 to articulate the end effector 3300 about the articulation joint 3330. The channel retainer 3360 comprises a plurality of sensors, such as a first sensor 3368a and a second sensor 3368b, for example. The sensors 3368a, 3368b are positioned distally with respect to the articulation joint 3330 in a firing member slot 3331 defined in the channel retainer 3360. The firing member 3353 is slidably positioned in the firing member slot 3331. Referring primarily to FIG. 34, the firing member 3353 comprises a plurality of features 3356a, 3357a, 3356b, 3357b, 3356c, 3357c, 3356d, and 3357d which are arranged in a staggered orientation comprising a first row 3355a of features 3356a-3356d offset from a second row 3355b of features 3357a-3357d. The first row 3355a of features 3356a-d is configured to be sensed by the first sensor 3368a. The second row 3355b of features 3357a-d is configured to be sensed by the second sensor 3368b. As the firing member 3353 moves distally through the channel retainer 3360 and the end effector 3300, the first sensor 3368a and the second sensor 3368b can sense the features 3356a-d and 3357a-d, respectively. As described in greater detail further below, the signals generated by the sensors 3368a, 3368b correspond with the position of the firing member 3353.

[0290] The sensors 3368a, 3368b are in signal communication with a microprocessor of the surgical instrument control system which is configured to receive and interpret the signals generated by the sensors 3368a, 3368b. The first sensor 3368a can transmit a first signal to the microprocessor. The first signal can comprise a series of pulses which corresponds to the sensor 3368a sensing the features 3356a-d. For example, the first sensor 3368a can transmit a high voltage potential across a first circuit in communication with an input channel of the microprocessor when the first sensor 3368a detects a feature 3356a-d positioned adjacent the first sensor 3368a and a low voltage potential across the first circuit when the first sensor 3368a does not detect a feature 3356a-d adjacent the first sensor 3368a. Similarly, the second sensor 3368a can transmit a high voltage potential across a second circuit in communication with an input channel of the microprocessor when the second sensor 3368b detects a feature 3357a-d positioned adjacent the second sensor 3368b and a low voltage potential across the second circuit when the second sensor 3368b does not detect a feature 3357a-d adjacent the second sensor 3368b. The microprocessor can count the pulses sent by the sensors indicating that a feature has passed a sensor and, based on that count, assess the position of the firing member 3353 during its firing stroke. In certain instances, the microprocessor can maintain a first count of the features 3356a-d that have passed the first sensor 3368a and a separate, second, count of the features 3356a-d that have passed the second sensor 3368b. In other instances, the microprocessor can maintain a combined count of the features 3356a-d and 3357a-d that have been sensed. In either event, the microprocessor can count the features 3356a-d and 3357a-d that have passed by the sensors 3368a and 3368b to determine whether the firing member 3353 has reached the end of its stroke.

[0291] In various instances, only one set of features 3356a-d and 3357a-d and one sensor 3368a and 3368b may be needed to determine the position of the firing member 3353. A single set of features may provide the microprocessor with an array of data which can be linked to another array of data which corresponds to the position of the firing member 3353. Utilizing a plurality of feature sets and sensors, however, provides the microprocessor with a matrix of data which can be linked to an array of data which corresponds to the position of the firing member 3353. Such a matrix of data is illustrated in FIG. 39.

[0292] The features 3356a-d and 3357a-d can comprise any suitable features which can be detected by the sensors 3368a and 3368b, respectively. In various instances, the features 3356a-d and 3357a-d can comprise magnetic elements and the sensors 3368a and 3368b can comprise Hall Effect sensors which can detect the magnetic elements, for example. In certain instances, the features 3356a-d and 3357a-d can comprise reflective elements and the sensors 3368a and 3368b can each comprise a signal emitter and receiver, for example. In at least one instance, the features 3356a-d and 3357a-d can comprise through holes. In at least one such instance, the sensors 3368a and 3368b can comprise optical sensors configured to detect a change in the color and/or reflectivity of the firing member 3353 as the features 3356a-d and 3357a-d pass by the sensors 3368a and 3368b, respectively. In certain instances, the sensors 3368a and 3368b can be configured to detect laser signals emitted from the opposite side of the firing member 3353, for example. In any event, the features 3356a-d can be positioned at regular intervals along the first row 3355a, for example. Similarly, the features 3357a-d can be positioned at regular intervals along the second row 3355b, for example. The microprocessor can be configured to evaluate the rate in which the features 3356a-d and/or the features 3357a-d are detected by the first sensor 3368a and the second sensor 3368b, respectively. In such instances, the microprocessor can also evaluate the speed, velocity and/or acceleration of the firing member 3353.

[0293] When the features 3356a-d and 3357a-d of the firing member 3353 comprise through holes, the through holes can comprise any suitable geometry, such as a circular geometry, for example. Turning now to FIG. 40, a firing member 3453 comprises an array of detectable features 3459 arranged along a longitudinal axis of the firing member 3453. In at least one instance, the detectable features 3459 comprise square through holes, for example. In certain instances, the detectable features 3459 comprise textured surfaces on the firing member 3453. In at least one such instance, the textured surfaces are square, for example.

[0294] FIG. 41 illustrates an alternative firing member 3553 of a firing assembly 3550 comprising teeth, or serrations, 3558 extending therefrom for use with an end effector assembly 3500. The teeth 3558 are arranged along a longitudinal axis of the firing member 3553 and gaps are present intermediate the teeth 3558. A sensor 3535 mounted to the end effector 3500 is configured to detect the teeth 3558 and/or the gaps between the teeth 3558 as the firing member 3353 is advanced distally. In at least one instance, the sensor 3535 can comprise an optical sensor, for example. The sensor 3535 is in signal communication with a microprocessor of a surgical instrument system. The sensor 3535 sends signals and/or signal pulses triggered by the teeth 3558 and/or the gaps positioned intermediate the teeth 3558 to indicate the position of the firing member 3553 as the firing assembly 3550 travels through the end effector 3500. The firing member 3353 can comprise a set, or predetermined, number of teeth 3558 which may trigger the sensor 3535 to send a set, or predetermined, number of signal pulses to the microprocessor to indicate the progression of the firing assembly 3550. The microprocessor can count the signal pulses that it receives from the sensor 3535 and compare the counted signal pulses to the predetermined number of pulses to assess whether the firing member 3553 has reached the end of stroke position and/or assess the distance that the firing member 3553 must travel before reaching its end of stroke position. The controller may count the teeth 3558 between the distal-most tooth 3558d which provides the microprocessor with the first signal pulse and the proximal-most tooth 3558p which provides the microprocessor with the last signal pulse. The end of stroke position may be detected once the microprocessor recognizes that the number of teeth 3558 sensed by the sensor 3535 is equal to the number of teeth 3558 that are on the firing member 3553.

[0295] An elongate channel 3610 is depicted in FIG. 42. The elongate channel 3610 can be used in accordance with various embodiments disclosed herein. The elongate channel 3610 is configured to support a staple cartridge of an end effector. The channel 3610 comprises a first cavity 3602 and a second cavity 3604 defined therein. The first cavity 3602 is located at a proximal portion 3601 of the channel 3610 and the second cavity 3604 is located at a distal portion 3603 of the channel 3610. The first cavity 3602 is configured to support a first, or proximal, sensor therein and the second cavity 3604 is configured to support a second, or distal, sensor therein. The sensors may be any suitable sensor configured to detect movement of a firing assembly. The proximal sensor is configured to detect whether the firing assembly is in its unfired, or unadvanced, position, for example. The distal sensor is configured to detect whether the firing assembly has reached the end of its firing stroke, for example.

[0296] FIG. 43 depicts a jaw 3710 for use with an end effector assembly 3700 of a surgical stapling instrument. The jaw 3710 comprises a staple cartridge 3712 and a firing assembly 3750. The staple cartridge 3712 comprises a longitudinal slot 3713 defined therein which is configured to receive the firing assembly 3750. The firing assembly 3750 is configured to travel between a proximal end 3701 and a distal end 3702 of the staple cartridge 3712. The firing assembly 3750 comprises a cutting member 3752 which includes, one, a cutting edge configured to incise tissue and, two, an electrically conductive portion for the purpose of providing an electrical path across the slot 3713, i.e., from one lateral side of the slot 3713 to the other. The staple cartridge 3712 comprises a conductive layer 3770 which is contacted by the conductive portion of the cutting member 3752 as the firing assembly 3750 travels through the staple cartridge 3712. The layer 3770 comprises a plurality of resistance regions, such as regions 3771, 3772, 3773, and 3774, for example. In at least one such instance, the layer 3770 extends along both sides of the slot 3713. FIG. 41 depicts only one of the two sides of the layer 3770. As described in greater detail further below, the resistance of a circuit created between the layer 3770 and the cutting member 3752 as the firing assembly 3750 progresses through the staple cartridge 3712 can be monitored and correlated with the position of the firing assembly 3750.

[0297] In various instances, further to the above, each resistance region 3771, 3772, 3773, and 3774 is comprised of an electrically-conductive material. In at least one such instance, the first resistance region 3771 is comprised of a first electrically-conductive material, the second resistance region 3772 is comprised of a second electrically-conductive material, the third resistance region 3773 is comprised of a third electrically-conductive material, and the fourth resistance region 3774 is comprised of a fourth electrically-conductive material. In various instances, the first material, the second material, the third material, and the fourth material are different electrically-conductive materials having different resistivities, for example. In certain instances, the first material, the second material, the third material, and/or the fourth material can be comprised of the same electrically-conductive material when the resistance regions having the same electrically-conductive material are not adjacent to each other. In any event, the resistance regions 3771, 3772, 3773, and 3774 are part of a firing progress detection circuit. The firing progress detection circuit further comprises a first conductor in communication with a first side of the layer 3770 and a second conductor in communication with a second side of the layer 3770. The first conductor and the second conductor are in communication with a microprocessor which can detect and evaluate the resistance of the firing progress detection circuit, as described in greater detail further below.

[0298] The resistance regions 3771, 3772, 3773, and 3774 of the layer 3770 can correspond to different positions of the cutting member 3752 and, correspondingly, different positions of the firing assembly 3750. The cutting member 3752 is movable through a firing stroke between a proximal, unadvanced position and a distal, fully-advanced position. When the cutting member 3752 is in its proximal, unadvanced position, the cutting member 3752 is in contact with the first resistance region 3771. Such a position can be referred to as a ‘home’ position of the cutting member 3752. When the cutting member 3752 is in contact with the first resistance region 3771, the firing progress detection circuit can have a first resistance which can be detected by the microprocessor. In such instances, the firing progress detection circuit can include the first conductor, the first side of the first resistance region 3771, the cutting member 3752, the second side of the first resistance region 3771, and the second conductor. When the microprocessor detects that the firing progress detection circuit has the first resistance, the microprocessor can determine that the cutting member 3752 is in its proximal-most position and that a full firing stroke is needed to completely fire the staples from the staple cartridge. While the first resistance of the firing progress detection circuit may comprise a specific first resistance, in various instances, it may also be inclusive of a first range of resistances.

[0299] When the cutting member 3752 is advanced distally from its home position, the cutting member 3752 can move out of contact with the first resistance region 3771 and into contact with the second resistance region 3772. Such a position can be referred to as the ‘lockout’ position of the cutting member 3752. The lockout position of the cutting member 3752 is the furthest distal position in which the cutting member 3752 can be advanced if an unexpended staple cartridge is not positioned in the first jaw 3710. When the cutting member 3752 is in contact with the second resistance region 3772, the firing progress detection circuit can have a second resistance which can be detected by the microprocessor. In such instances, the firing progress detection circuit can include the first conductor, the first side of the second resistance region 3772, the cutting member 3752, the second side of the second resistance region 3772, and the second conductor. When the microprocessor detects that the firing progress detection circuit has the second resistance, the microprocessor can determine that the cutting member 3752 is in its lockout position and that the cutting member 3752 may be blocked from being advanced distally if an unspent staple cartridge is not positioned in the first jaw 3710. In various instances, as a result, the microprocessor may operate an electric motor which drives the firing assembly 3750 distally at a reduced speed when moving the cutting member 3752 distally from the second resistance region 3772 to the third resistance region 3773 in the event that the cutting member 3752 contacts the lockout. While the second resistance of the firing progress detection circuit may comprise a specific second resistance, in various instances, it may also be inclusive of a second range of resistances.

[0300] When the cutting member 3752 is advanced distally from its lockout position, the cutting member 3752 can move out of contact with the second resistance region 3772 and into contact with the third resistance region 3773. The third resistance region 3773 corresponds to a range of positions in which the firing assembly 3750 is ejecting the staples from the staple cartridge 3712. When the cutting member 3752 is in contact with the third resistance region 3773, the firing progress detection circuit can have a third resistance which can be detected by the microprocessor. In such instances, the firing progress detection circuit can include the first conductor, the first side of the third resistance region 3773, the cutting member 3752, the second side of the third resistance region 3773, and the second conductor. When the microprocessor detects that the firing progress detection circuit has the third resistance, the microprocessor can determine that the firing assembly 3750 is firing the staples into tissue and that the cutting member 3752 is incising the tissue. In various instances, the microprocessor may operate the electric motor which drives the firing assembly 3750 at a suitable speed as the cutting member 3752 moves through the third resistance region 3773. A suitable speed may comprise a constant speed, for example. In some instances, the cutting member 3752 may be accelerated at the proximal end of the third resistance region 3773 and decelerated at the distal end of the third resistance region 3773, for example. While the third resistance of the firing progress detection circuit may comprise a specific third resistance, in various instances, it may also be inclusive of a third range of resistances.

[0301] When the cutting member 3752 is advanced distally from its staple firing range, the cutting member 3752 can move out of contact with the third resistance region 3773 and into contact with the fourth resistance region 3774. The fourth resistance region 3774 corresponds to the distal-most, fully-fired position of the cutting member 3752. When the cutting member 3752 is in contact with the fourth resistance region 3774, the firing progress detection circuit can have a fourth resistance which can be detected by the microprocessor. In such instances, the firing progress detection circuit can include the first conductor, the first side of the fourth resistance region 3774, the cutting member 3752, the second side of the fourth resistance region 3774, and the second conductor. When the microprocessor detects that the firing progress detection circuit has the fourth resistance, the microprocessor can determine that the firing assembly 3750 is at the end of its firing stroke. At such point, the microprocessor may stop the electric motor which drives the firing assembly 3750. In some instances, the microprocessor may automatically reverse the direction of the electric motor and retract the cutting member 3752. The sled 3251 may be left at the distal end 3702 of the staple cartridge 3712 or retracted proximally with the cutting member 3752. While the fourth resistance of the firing progress detection circuit may comprise a specific fourth resistance, in various instances, it may also be inclusive of a fourth range of resistances.

[0302] Detecting the first, second, third, and fourth resistances can provide real time position detection of the firing assembly 3750. While four resistance regions are utilized in the illustrated embodiment, any suitable number of resistance regions may be utilized.

[0303] Means for detecting when a firing assembly has attained an end of stroke position can also be located within a handle assembly of a surgical stapling instrument. A handle assembly 4100 is depicted in FIG. 44. The handle assembly 4100 comprises a motor 4110 and a gear assembly 4130. Operably meshed with the gear assembly 4130 is a firing member 4150. The motor 4110 may be actuated by a user-actuated firing actuator 4111 in order to drive the gear assembly 4130 and consequently drive the firing member 4150. The handle assembly 4100 also comprises a cavity 4121 configured to house a sensor. The sensor can be configured to detect the position, velocity, and/or acceleration of the firing member 4150. The firing member 4150 comprises markings 4151. The markings 4151 may be printed on the firing bar 4153, for example. Alternative embodiments present markings that are etched in the firing member 4150, for example. The firing member 4150 can be comprised of any suitable material, such as plastic, fiberglass-filled plastic, stainless steel, and/or glass, for example. The sensor can be any suitable sensor configured to sense the markings 4151 of the firing bar 4150. The markings 4151 may extend longitudinally along the firing member 4150 in any suitable orientation on any suitable side thereof which can be detected by the sensor positioned within the cavity 4121. The sensor can be positioned within the cavity 4121 to sense markings 4151 of the firing member 4150 as the firing member 4150 travels longitudinally within the surgical stapling instrument.

[0304] Another system in which the position, velocity and/or acceleration of a firing assembly may be detected can comprise audible and/or haptic means configured to notify the user of the surgical instrument, with sound and/or vibration, the position, velocity and/or acceleration of the firing member. Illustrated in FIGS. 45-46 is a partial view of a firing assembly 4200 for use with a surgical stapling instrument. Positioned at least partially within a handle assembly of the instrument, the firing assembly 4200 is configured to fire a plurality of staples removably stored within an end effector, for example. The firing assembly 4200 comprises a firing member 4250, a drive gear 4215, and a motor 4210. The motor 4210 is mounted to a handle frame, or chassis, 4220. The motor 4210 can be actuated by a user-actuated firing actuator of the surgical instrument in order to drive, or rotate, the drive gear 4215. The firing member 4250 comprises a longitudinal array of drive teeth 4255 operably meshed with the drive gear 4215. When driven by the motor 4210 in a first direction, the drive gear 4215 drives the firing member 4250 distally toward the end effector. The firing member 4250 further comprises a longitudinal array of haptic ribs, or teeth, 4251 configured to engage a haptic spring 4256 mounted in the handle frame 4220. An audible click and/or vibration is made each time a haptic rib 4251 strikes, deflects, and passes by the haptic spring 4256.

[0305] As the firing member 4250 is advanced distally, further to the above, the user of the surgical instrument can be audibly alerted, for example, of the status of the firing assembly 4250 as the haptic ribs 4251 engage the haptic spring 4255. If the firing member 4250 is moving at a constant speed, the rate in which the clicks are made will be constant. If the firing member 4250 is being accelerated, the rate in which the clicks are made will increase. If the firing member 4250 is being decelerated, the rate in which the clicks are made will decrease. The haptic ribs 4251 comprise a denser arrangement 4252 at the proximal end 4257 of the firing member 4250 as compared to the haptic ribs 4251 distal to the proximal end 4257. For a given speed of the firing member 4250, the haptic ribs 4251 positioned at the proximal end 4257 of the firing member 4250, i.e., ribs 4252, cause the audible alert created by the haptic spring 4256 to be different than that of the alert created by the haptic spring 4256 when the haptic spring 4256 engages the haptic ribs 4251 distal to the proximal end 4257. In at least one such instance, the ribs 4252 quicken the rate of the clicking heard by and/or the vibrations felt by the user. Upon hearing an increased rate of the clicking caused by the ribs 4252, for example, the user of the surgical instrument may understand that the firing member 4250 may be approaching, or has arrived at, the end of stroke position. In such instances, the user may release the firing actuator which is driving the electric motor 4210 to stop the firing member 4250. In the instances where the firing actuator comprises a variable speed control over the motor 4210, the user can relax the pressure being applied to the firing actuator to slow the motor 4210 before releasing the firing actuator to stop the motor 4210. At such point, the firing member 4250 can be retracted proximally by operating the motor 4210 in a second, or opposite, direction.

[0306] As described above, a longitudinal array of ribs can include two portions—a first portion that establishes a baseline of feedback and a second portion which provides a departure in that feedback. Other embodiments are envisioned which comprise a baseline feedback and more than one additional feedback which departs from the baseline feedback. In various instances, a final feedback can comprise an accelerating rate of audible clicks and/or vibrations, for example, as the firing member gets closer to its end of stroke position, for example.

[0307] The audible clicks and/or vibrations, or haptic feedback, described above in connection with the embodiment of FIGS. 45 and 46 are generated within and emanate from the handle of the surgical instrument. In addition to or in lieu of the above, audible clicks and/or vibrations can be generated within and emanate from the shaft and/or end effector of the surgical instrument. Turning now to FIG. 48, a cutting element 4452 is configured to engage a longitudinal array of ribs positioned in a first jaw 4410 of an end effector 4400 as the cutting element 4456 is advanced distally. Similar to the above, the ribs can indicate the position of the cutting element 4452 by generating clicking sounds and/or vibrations as the cutting element 4452 passes thereby. The longitudinal array of ribs 4455 comprises a first portion 4455 which comprises ribs spaced a first distance apart, a second portion 4456 which comprises ribs spaced a second distance apart, and a third portion 4457 which comprises ribs a third distance apart. The second distance is shorter than the first distance and the third distance is shorter than the second distance, for example. The cutting element 4452 comprises a haptic nodule 4454 extending therefrom which is configured to engage and slide across the ribs to generate a clicking sound and/or vibration for each rib that the haptic nodule 4454 contacts. For a given speed of the cutting element 4452, the first portion 4455 will create clicks and/or vibrations at a first rate, the second portion 4456 will create clicks and/or vibrations at a second rate, and the third position 4457 will create clicks and/or vibrations at a third rate. The second rate is faster than the first rate and the third rate is faster than the second rate, for example. A user hearing an increase in the pace of the clicks, for example, would indicate to the user that the cutting element 4452 is reaching its end of stroke position. A user may respond to this feedback by slowing down and/or stopping the cutting element 4452.

[0308] In FIG. 47, a partial view of a handle assembly is shown. The handle assembly 4300 comprises a drive assembly 4320 for use in conjunction with a clutch assembly 4330 configured to limit the amount of torque transferred to a firing member 4350 of the drive assembly 4320. The drive assembly 4320 comprises an electric motor, a planetary gear train 4331 operably coupled to an output shaft of the electric motor, a clutch shaft 4332, a clutch drive plate 4334, a release spring 4333, an output shaft 4338, an output gear 4339, and a firing member 4350. The electric motor drives the planetary gear train 4331 in order to rotate the clutch shaft 4332. It can also be appreciated that the clutch shaft 4332 may be driven manually by a handcrank, for example. The clutch shaft 4332 is coupled with the clutch drive plate 4334 such that the rotation of the clutch shaft 4332 is transferred to the clutch drive plate 4334. More particularly, the clutch drive plate 4334 is keyed to the clutch shaft 4332 such that the clutch drive plate 4334 is rotatable with the clutch shaft 4332; however, the clutch drive plate 4334 is slidable relative to the clutch shaft 4322. As described in greater detail further below, the clutch drive plate 4334 comprises teeth 4336 configured to operably engage and operably disengage from teeth 4337 on the output shaft 4338. When the teeth 4336 of the clutch drive plate 4334 are operably engaged with the teeth 4337 of the output shaft 4338, the rotation of the clutch drive plate 4334 is transferred to the output shaft 4338. The output gear 4339 is coupled to the output shaft 4338 such that the rotation of the output shaft 4338, if any, is transferred to the output gear 4339. The output gear 4339 is operably engaged with the firing member 4350 in order advance the firing member 4350 distally and/or retract the firing member 4350 proximally, depending on the direction in which the output gear 4339 is rotated.

[0309] Further to the above, the release spring 4333 biases the clutch drive plate 4334 into engagement with the output shaft 4338. More specifically, the release spring 4333 biases the teeth 4336 of the clutch drive plate 4334 into operative engagement with the teeth 4337 of the output shaft 4338. Owing to angled surfaces on the teeth 4336, 4337, the teeth 4336, 4337 may tend to push the clutch drive plate 4334 away from the output shaft 4338 when a working load is transmitted therebetween. The release spring 4333 can be designed to handle a particular, or predetermined, working load applied between the clutch drive plate 4334 and the output shaft 4338. Such a predetermined working load is sufficient to operate the end effector of the surgical instrument under normal operating conditions. For example, the predetermine working load is sufficient to fire and properly deform the staples removably stored in a staple cartridge and incise the tissue being stapled. In the event that the firing member 4350 becomes jammed, for example, the motor may attempt to transmit a larger working load than the predetermined working load through the clutch assembly. In such instances, the release spring 4333 may be overcome and the clutch drive plate 4334 may be pushed out of engagement with the output shaft 4338. At such point, the clutch drive plate 4334 may rotate relative to the output shaft 4338 without transferring, or at least substantially transferring, relative rotational movement therebetween.

[0310] When the firing member 4350 has reached the end of its firing stroke, further to the above, the firing member 4350 may abut a distal end of the staple cartridge, for example. In such circumstances, the distal end of the staple cartridge will stop the advancement of the firing member 4350 and, similar to the above, the teeth 4336 of the clutch drive plate 4334 will slip relative to the teeth 4337 of the output shaft 4338 and/or de-mesh as a result of the increased torque being transmitted from the electric motor to the clutch drive plate 4334 in an attempt to advance the firing member 4350 further distally. The force of the release spring 4333 applied to the clutch drive plate 4334 is not great enough to keep the teeth 4336 of the clutch drive plate 4334 and the teeth 4337 of the output shaft 4338 engaged to drive the output gear 4339. When the electric motor is operated in an opposite direction, for example, the torque being transmitted into the clutch interface which is causing the clutch to slip will be released and the teeth 4336 will be remeshed with the teeth 4337 in order to retract the firing member 4350 proximally.

[0311] Another embodiment can comprise a sensor positioned within a firing assembly configured to sense force experienced by the firing assembly as the firing assembly reaches a distal end of an end effector. At the distal end of an end effector, a stop may be configured to arrest the distal movement of the firing member assembly. The stop may be designed to provide a known resistive force profile in which a controller of the surgical instrument can detect and/or measure to notify a user that the firing assembly is at the end of stroke position. Different force profiles will occur depending on the design of the stop. The stop may be breakable and designed with a discontinuity ensuring material failure open arrival of the firing assembly at the end of stroke position. A stepped stop may be designed to gradually arrest the movement of the cutting member. Once the cutting member contacts the distal wall of the stepped stop, the firing assembly will have reached the distal-most position. The controller may look for a first expected force to notify the user of the surgical instrument that the firing member assembly is nearing the end of stroke position. The controller may also look for a second expected force the firing member will experience when the firing member reaches an end of stroke position.

[0312] A surgical instrument system comprising an end effector including an anvil, a staple cartridge comprising a proximal end, a distal end, a plurality of staple cavities, and a plurality of staples removably stored in the staple cavities, and a sled slidable within the staple cartridge to move the staples toward the anvil. The surgical instrument system further comprising a firing member movable relative to the staple cartridge to move the sled from the proximal end toward the distal end of the staple cartridge during a firing stroke, a shaft defining a longitudinal axis, an articulation joint, wherein the end effector is rotatably connected to the shaft about the articulation joint between an unarticulated position and an articulated position, and adjusting means for adjusting the length of the firing stroke as a function of the degree in which the end effector is articulated relative to the longitudinal axis.

[0313] The surgical instrument system of Example 1, further comprising means for determining the position of the firing member during the firing stroke.

[0314] The surgical instrument system of Examples 2 or 3, further comprising sensing means for sensing the degree of articulation of the end effector relative to the longitudinal axis.

[0315] The surgical instrument system of Example 3, further comprising a flexible firing bar extending through the articulation joint, wherein the flexible firing bar comprises a plurality of lateral portions, and wherein the sensing means comprises means for detecting the relative positions of the lateral portions.

[0316] The surgical instrument system of Examples 3 or 4, wherein the adjusting means comprises a controller in communication with the sensing means, wherein the controller is configured to adjust the length of the firing stroke based on feedback from the sensing means.

[0317] The surgical instrument system of Examples 1, 2, 3, 4, or 5, wherein the adjusting means comprises a firing path shifter.

[0318] A surgical instrument system, comprising an end effector including an anvil and a staple cartridge comprising a plurality of staple cavities and a plurality of staples removably stored in the staple cavities, a shaft defining a longitudinal axis, and an articulation joint, wherein the end effector is rotatably connected to the shaft at the articulation joint between an unarticulated position and a plurality of articulated positions relative to the longitudinal axis. The surgical instrument system further comprises a flexible firing bar extending through the articulation joint, wherein the flexible firing bar comprises a proximal end positioned proximal to the articulation joint, a distal end positioned distal to the articulation joint, and a plurality of lateral portions extending through the articulation joint, wherein the lateral portions are configured to shift relative to each other at the proximal end when the end effector is moved to an articulated position. The surgical instrument system further comprises a sensor configured to defect shifting between a first lateral portion and a second lateral portion at the proximal end of the flexible firing bar.

[0319] The surgical instrument system of Example 7, wherein the sensor comprises a Hall effect sensor, and wherein at least one magnet is positioned on the flexible firing bar.

[0320] The surgical instrument system of Examples 7 or 8, wherein the sensor comprises a linear encoder.

[0321] The surgical instrument system of Examples 7, 8, or 9, wherein the sensor comprises a rotary encoder.

[0322] The surgical instrument system of Examples 7, 8, 9, or 10, wherein the sensor comprises a flexible band comprising an electrically active polymer.

[0323] The surgical instrument system of Examples 7, 8, 9, 10, or 11, wherein the sensor comprises at least one first contact on the first lateral portion, and at least one second contact on the second lateral portion, wherein the second lateral portion is adjacent to the first lateral portion.

[0324] A surgical instrument system comprising an end effector including an anvil and a staple cartridge comprising a plurality of staple cavities and a plurality of staples removably stored in the staple cavities, a shaft defining a longitudinal axis, an articulation joint, wherein the end effector is rotatably connected to the shaft at the articulation joint between an unarticulated position and at least one articulated position relative to the longitudinal axis, a flexible firing member extending through the articulation joint, wherein the flexible firing member comprises a plurality of lateral portions, and wherein the lateral portions are configured to shift relative to each other when the end effector is moved to the at least one articulated position, and a relief feature configured to accommodate shifting of the lateral portions of the flexible firing member.

[0325] The surgical instrument system of Example 13, further comprising a rigid firing rod extending through the shaft, wherein the rigid firing rod is coupled to the flexible firing member, and wherein the relief feature is positioned intermediate the flexible firing member and the rigid firing rod.

[0326] The surgical instrument system of Examples 13 or 14, wherein the flexible firing member is comprised of a first material having a first durometer hardness, wherein the relief feature is comprised of a second material having a second durometer hardness, and wherein the second durometer hardness is less than the first durometer hardness.

[0327] The surgical instrument system of Examples 13, 14, or 15, wherein the staple cartridge further comprises a sled slidable within the staple cartridge to move the staples toward the anvil, and wherein the relief feature is positioned intermediate the sled and the flexible firing member.

[0328] The surgical instrument system of Examples 13, 14, 15, or 16, wherein a longitudinal slot is defined through at least a portion of the staple cartridge, and wherein the relief feature comprises a bridge extending across the longitudinal slot.

[0329] The surgical instrument system of Examples 13, 14, 15, 16, or 17, wherein the relief feature comprises a frangible member.

[0330] The surgical instrument system of Examples 13, 14, 15, 16, 17, or 18, wherein the staple cartridge comprises a distal end wall, and wherein the relief feature comprises at least one aperture through the distal end wall.

[0331] The surgical instrument system of Examples 13, 14, 15, 16, 17, 18, or 19 wherein the relief feature comprises a hard stop comprising a plurality of steps.

[0332] The entire disclosures of the following documents are hereby incorporated by reference herein in their respective entireties:

• [0333] U.S. Pat. No. 5,403,312, entitled ELECTROSURGICAL HEMOSTATIC DEVICE, which issued on Apr. 4, 1995;
• [0334] U.S. Pat. No. 7,000,818, entitled SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS, which issued on Feb. 21, 2006;
• [0335] U.S. Pat. No. 7,422,139, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH TACTILE POSITION FEEDBACK, which issued on Sep. 9, 2008;
• [0336] U.S. Pat. No. 7,464,849, entitled ELECTRO-MECHANICAL SURGICAL INSTRUMENT WITH CLOSURE SYSTEM AND ANVIL ALIGNMENT COMPONENTS, which issued on Dec. 16, 2008;
• [0337] U.S. Pat. No. 7,670,334, entitled SURGICAL INSTRUMENT HAVING AN ARTICULATING END EFFECTOR, which issued on Mar. 2, 2010;
• [0338] U.S. Pat. No. 7,753,245, entitled SURGICAL STAPLING INSTRUMENTS, which issued on Jul. 13, 2010;
• [0339] U.S. Pat. No. 8,393,514, entitled SELECTIVELY ORIENTABLE IMPLANTABLE FASTENER CARTRIDGE, which issued on Mar. 12, 2013;
• [0340] U.S. patent application Ser. No. 11/343,803, entitled SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES; now U.S. Pat. No. 7,845,537;
• [0341] U.S. patent application Ser. No. 12/031,573, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT HAVING RF ELECTRODES, filed Feb. 14, 2008;
• [0342] U.S. patent application Ser. No. 12/031,873, entitled END EFFECTORS FOR A SURGICAL CUTTING AND STAPLING INSTRUMENT, filed Feb. 15, 2008, now U.S. Pat. No. 7,980,443;
• [0343] U.S. patent application Ser. No. 12/235,782, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT, now U.S. Pat. No. 8,210,411;
• [0344] U.S. patent application Ser. No. 12/249,117, entitled POWERED SURGICAL CUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM, now U.S. Pat. No. 8,608,045;
• [0345] U.S. patent application Ser. No. 12/647,100, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT WITH ELECTRIC ACTUATOR DIRECTIONAL CONTROL ASSEMBLY, filed Dec. 24, 2009; now U.S. Pat. No. 8,220,688;
• [0346] U.S. patent application Ser. No. 12/893,461, entitled STAPLE CARTRIDGE, filed Sep. 29, 2012, now U.S. Pat. No. 8,733,613;
• [0347] U.S. patent application Ser. No. 13/036,647, entitled SURGICAL STAPLING INSTRUMENT, filed Feb. 28, 2011, now U.S. Pat. No. 8,561,870;
• [0348] U.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Patent Application Publication No. 2012/0298719;
• [0349] U.S. patent application Ser. No. 13/524,049, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, filed on Jun. 15, 2012; now U.S. Patent Application Publication No. 2013/0334278;
• [0350] U.S. patent application Ser. No. 13/800,025, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013;
• [0351] U.S. patent application Ser. No. 13/800,067, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013;
• [0352] U.S. Patent Application Publication No. 2007/0175955, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT WITH CLOSURE TRIGGER LOCKING MECHANISM, filed Jan. 31, 2006; and
• [0353] U.S. Patent Application Publication No. 2010/0264194, entitled SURGICAL STAPLING INSTRUMENT WITH AN ARTICULATABLE END EFFECTOR, filed Apr. 22, 2010, now U.S. Pat. No. 8,308,040.

[0354] Although the various embodiments of the devices have been described herein in connection with certain disclosed embodiments, many modifications and variations to those embodiments may be implemented. 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.

[0355] The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.

[0356] Preferably, the invention described herein will be processed before surgery. First, a new or used instrument is obtained and if necessary cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument are then placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation kills bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility.

[0357] 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.

[0358] Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.