SURGICAL STAPLER HAVING MOTOR CONTROL BASED ON AN ELECTRICAL PARAMETER RELATED TO A MOTOR CURRENT

BACKGROUND

[0001] The invention disclosed herein 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.

[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.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Various features of the embodiments described herein, together with advantages thereof, may be understood in accordance with the following description taken in conjunction with the accompanying drawings as follows:

[0005] FIG. 1 is a perspective view of a surgical instrument that has an interchangeable shaft assembly operably coupled thereto;

[0006] FIG. 2 is an exploded assembly view of the interchangeable shaft assembly and surgical instrument of FIG. 1; [0007] FIG. 3 is another exploded assembly view showing portions of the interchangeable shaft assembly and surgical instrument of FIGS. 1 and 2;

[0008] FIG. 4 is an exploded assembly view of a portion of the surgical instrument of FIGS. 1-3;

[0009] FIG. 5 is a cross-sectional side view of a portion of the surgical instrument of FIG. 4 with the firing trigger in a fully actuated position;

[0010] FIG. 6 is another cross-sectional view of a portion of the surgical instrument of FIG. 5 with the firing trigger in an unactuated position;

[0011] FIG. 7 is an exploded assembly view of one form of an interchangeable shaft assembly;

[0012] FIG. 8 is another exploded assembly view of portions of the interchangeable shaft assembly of FIG. 7;

[0013] FIG. 9 is another exploded assembly view of portions of the interchangeable shaft assembly of FIGS. 7 and 8;

[0014] FIG. 10 is a cross-sectional view of a portion of the interchangeable shaft assembly of FIGS. 7-9;

[0015] FIG. 11 is a perspective view of a portion of the shaft assembly of FIGS. 7-10 with the switch drum omitted for clarity;

[0016] FIG. 12 is another perspective view of the portion of the interchangeable shaft assembly of FIG. 11 with the switch drum mounted thereon;

[0017] FIG. 13 is a perspective view of a portion of the interchangeable shaft assembly of FIG. 11 operably coupled to a portion of the surgical instrument of FIG. 1 illustrated with the closure trigger thereof in an unactuated position;

[0018] FIG. 14 is a right side elevational view of the interchangeable shaft assembly and surgical instrument of FIG. 13;

[0019] FIG. 15 is a left side elevational view of the interchangeable shaft assembly and surgical instrument of FIGS. 13 and 14;

[0020] FIG. 16 is a perspective view of a portion of the interchangeable shaft assembly of FIG. 11 operably coupled to a portion of the surgical instrument of FIG. 1 illustrated with the closure trigger thereof in an actuated position and a firing trigger thereof in an unactuated position;

[0021] FIG. 17 is a right side elevational view of the interchangeable shaft assembly and surgical instrument of FIG. 16;

[0022] FIG. 18 is a left side elevational view of the interchangeable shaft assembly and surgical instrument of FIGS. 16 and 17; [0023] FIG. 18A is a right side elevational view of the interchangeable shaft assembly of FIG. 11 operably coupled to a portion of the surgical instrument of FIG. 1 illustrated with the closure trigger thereof in an actuated position and the firing trigger thereof in an actuated position;

[0024] FIG. 19 is a schematic of a system for powering down an electrical connector of a surgical instrument handle when a shaft assembly is not coupled thereto;

[0025] FIG. 20 is an exploded view of one aspect of an end effector of the surgical instrument of FIG. 1;

[0026] FIGS. 21A-21B is a circuit diagram of the surgical instrument of FIG. 1 spanning two drawings sheets;

[0027] FIG. 22 illustrates one instance of a power assembly comprising a usage cycle circuit configured to generate a usage cycle count of the battery back;

[0028] FIG. 23 illustrates one aspect of a process for sequentially energizing a segmented circuit;

[0029] FIG. 24 illustrates one aspect of a power segment comprising a plurality of daisy chained power converters;

[0030] FIG. 25 illustrates one aspect of a segmented circuit configured to maximize power available for critical and/or power intense functions;

[0031] FIG. 26 illustrates one aspect of a power system comprising a plurality of daisy chained power converters configured to be sequentially energized;

[0032] FIG. 27 illustrates one aspect of a segmented circuit comprising an isolated control section;

[0033] FIG. 28, which is divided into FIGS. 28A and 28B, is a circuit diagram of the surgical instrument of FIG. 1;

[0034] FIG. 29 is a block diagram the surgical instrument of FIG. 1 illustrating interfaces between the handle assembly 14 and the power assembly and between the handle assembly 14 and the interchangeable shaft assembly;

[0035] FIG. 30 illustrates a simplified representation of various embodiments of a surgical stapler;

[0036] FIG. 31 illustrates a simplified representation of various embodiments of a surgical stapler;

[0037] FIG. 32 illustrates a simplified representation of various embodiments of a surgical stapler;

[0038] FIG. 33 illustrates exemplary battery current and recirculation current waveforms of a surgical stapler according to various embodiments; and

[0039] FIG. 34 illustrates an exemplary sampling of a battery current of various embodiments of a surgical stapler over multiple periods of a PWM duty cycle. [0040] 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.

DETAILED DESCRIPTION

[0041] Applicant of the present application owns the following patent applications that were filed on even date herewith and which are each herein incorporated by reference in their respective entireties:

U.S. Patent Application Serial No. , entitled SURGICAL STAPLER HAVING

DOWNSTREAM CURRENT-BASED MOTOR CONTROL; Attorney Docket No.

END7660USNP/150095;

U.S. Patent Application Serial No. , entitled SURGICAL STAPLER HAVING

MOTOR CONTROL BASED ON A DRIVE SYSTEM COMPONENT; Attorney Docket No.

END7661USNP/150096;

U.S. Patent Application Serial No. , entitled SURGICAL STAPLER HAVING

TEMPERATURE-BASED MOTOR CONTROL; Attorney Docket No. END7662USNP/150097;

U.S. Patent Application Serial No. , entitled SURGICAL STAPLER HAVING

MAGNETIC FIELD-BASED MOTOR CONTROL; Attorney Docket No. END7663USNP/150098;

U.S. Patent Application Serial No. , entitled SURGICAL STAPLER HAVING

FORCE-BASED MOTOR CONTROL; Attorney Docket No. END7664USNP/150099; and

U.S. Patent Application Serial No. , entitled SURGICAL STAPLER HAVING

CURRENT MIRROR-BASED MOTOR CONTROL; Attorney Docket No.

END7665USNP/150100.

[0042] Applicant of the present application owns the following patent applications that were filed on March 6, 2015 and which are each herein incorporated by reference in their respective entireties:

U.S. Patent Application Serial No. 14/640,746, entitled POWERED SURGICAL

INSTRUMENT;

U.S. Patent Application Serial No. 14/640,765, entitled SYSTEM FOR DETECTING THE MIS-INSERTION OF A STAPLE CARTRIDGE INTO A SURGICAL STAPLER; U.S. Patent Application Serial No. 14/640,780, entitled SURGICAL INSTRUMENT COMPRISING A LOCKABLE BATTERY HOUSING;

U.S. Patent Application Serial No. 14/640,795, entitled MULTIPLE LEVEL

THRESHOLDS TO MODIFY OPERATION OF POWERED SURGICAL INSTRUMENTS;

U.S. Patent Application Serial No. 14/640,799, entitled SIGNAL AND POWER

COMMUNICATION SYSTEM POSITIONED ON A ROTATABLE SHAFT;

U.S. Patent Application Serial No. 14/640,817, entitled INTERACTIVE FEEDBACK SYSTEM FOR POWERED SURGICAL INSTRUMENTS;

U.S. Patent Application Serial No. 14/640,831, entitled MONITORING SPEED CONTROL AND PRECISION INCREMENTING OF MOTOR FOR POWERED SURGICAL INSTRUMENTS;

U.S. Patent Application Serial No. 14/640,832, entitled ADAPTIVE TISSUE

COMPRESSION TECHNIQUES TO ADJUST CLOSURE RATES FOR MULTIPLE TISSUE TYPES;

U.S. Patent Application Serial No. 14/640,837, entitled SMART SENSORS WITH LOCAL SIGNAL PROCESSING;

U.S. Patent Application Serial No. 14/640,844, entitled CONTROL TECHNIQUES AND SUB-PROCESSOR CONTAINED WITHIN MODULAR SHAFT WITH SELECT CONTROL PROCESSING FROM HANDLE;

U.S. Patent Application Serial No. 14/640,859, entitled TIME DEPENDENT

EVALUATION OF SENSOR DATA TO DETERMINE STABILITY, CREEP, AND

VISCOELASTIC ELEMENTS OF MEASURES; and

U.S. Patent Application Serial No. 14/640,935, entitled OVERLAID MULTI SENSOR RADIO FREQUENCY (RF) ELECTRODE SYSTEM TO MEASURE TISSUE COMPRESSION.

[0043] Applicant of the present application owns the following patent applications that were filed on February 27, 2015, and which are each herein incorporated by reference in their respective entireties:

U.S. Patent Application Serial No. 14/633,526, entitled ADAPTABLE SURGICAL INSTRUMENT HANDLE;

U.S. Patent Application Serial No. 14/633,541, entitled MODULAR STAPLING

ASSEMBLY; U.S. Patent Application Serial No. 14/633,542, entitled REINFORCED BATTERY FOR A SURGICAL INSTRUMENT;

U.S. Patent Application Serial No. 14/633,546, entitled SURGICAL APPARATUS CONFIGURED TO ASSESS WHETHER A PERFORMANCE PARAMETER OF THE SURGICAL APPARATUS IS WITHIN AN ACCEPTABLE PERFORMANCE BAND;

U.S. Patent Application Serial No. 14/633,548, entitled POWER ADAPTER FOR A SURGICAL INSTRUMENT;

U.S. Patent Application Serial No. 14/633,555, entitled SYSTEM FOR MONITORING WHETHER A SURGICAL INSTRUMENT NEEDS TO BE SERVICED;

U.S. Patent Application Serial No. 14/633,560, entitled SURGICAL CHARGING SYSTEM THAT CHARGES AND/OR CONDITIONS ONE OR MORE BATTERIES;

U.S. Patent Application Serial No. 14/633,562, entitled SURGICAL APPARATUS CONFIGURED TO TRACK AN END-OF-LIFE PARAMETER;

U.S. Patent Application Serial No. 14/633,566, entitled CHARGING SYSTEM THAT ENABLES EMERGENCY RESOLUTIONS FOR CHARGING A BATTERY; and

U.S. Patent Application Serial No. 14/633,576, entitled SURGICAL INSTRUMENT SYSTEM COMPRISING AN INSPECTION STATION.

[0044] Applicant of the present application owns the following patent applications that were filed on December 18, 2014 and which are each herein incorporated by reference in their respective entireties:

U.S. Patent Application Serial No. 14/574,478, entitled SURGICAL INSTRUMENT SYSTEMS COMPRISING AN ARTICULATABLE END EFFECTOR AND MEANS FOR ADJUSTING THE FIRING STROKE OF A FIRING;

U.S. Patent Application Serial No. 14/574,483, entitled SURGICAL INSTRUMENT ASSEMBLY COMPRISING LOCKABLE SYSTEMS;

U.S. Patent Application Serial No. 14/574,493, entitled SURGICAL INSTRUMENT ASSEMBLY COMPRISING A FLEXIBLE ARTICULATION SYSTEM;

U.S. Patent Application Serial No. 14/574,500, entitled SURGICAL INSTRUMENT ASSEMBLY COMPRISING A LOCKABLE ARTICULATION SYSTEM;

U.S. Patent Application Serial No. 14/575,117, entitled SURGICAL INSTRUMENTS WITH ARTICULATABLE END EFFECTORS AND MOVABLE FIRING BEAM SUPPORT ARRANGEMENTS; U.S. Patent Application Serial 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;

U.S. Patent Application Serial No. 14/575, 139, entitled DRIVE ARRANGEMENTS FOR ARTICULATABLE SURGICAL INSTRUMENTS;

U.S. Patent Application Serial No. 14/575,143, entitled SURGICAL INSTRUMENTS WITH FMPROVED CLOSURE ARRANGEMENTS;

U.S. Patent Application Serial No. 14/575,148, entitled LOCKING ARRANGEMENTS FOR DETACHABLE SHAFT ASSEMBLIES WITH ARTICULATABLE SURGICAL END EFFECTORS; and

U.S. Patent Application Serial No. 14/575,154, entitled SURGICAL INSTRUMENTS WITH ARTICULATABLE END EFFECTORS AND FMPROVED FIRING BEAM SUPPORT ARRANGEMENTS.

[0045] Applicant of the present application also owns the following patent applications that were filed on September 5, 2014 and which are each herein incorporated by reference in their respective entireties:

U.S. Patent Application Serial No. 14/478,895, entitled MULTIPLE SENSORS WITH ONE SENSOR AFFECTING A SECOND SENSO S OUTPUT OR INTERPRETATION;

U.S. Patent Application Serial No. 14/478,908, entitled MONITORING DEVICE

DEGRADATION BASED ON COMPONENT EVALUATION;

U.S. Patent Application Serial No. 14/479,098, entitled SMART CARTRIDGE WAKE UP OPERATION AND DATA RETENTION;

U.S. Patent Application Serial No. 14/479,103, entitled CIRCUITRY AND SENSORS FOR POWERED MEDICAL DEVICE;

U.S. Patent Application Serial No. 14/479,108, entitled LOCAL DISPLAY OF TISSUE PARAMETER STABILIZATION;

U.S. Patent Application Serial No. 14/479,110, entitled USE OF POLARITY OF HALL MAGNET DETECTION TO DETECT MISLOADED CARTRIDGE;

U.S. Patent Application Serial No. 14/479,115, entitled MULTIPLE MOTOR CONTROL FOR POWERED MEDICAL DEVICE; and

U.S. Patent Application Serial No. 14/479,119, entitled ADJUNCT WITH INTEGRATED SENSORS TO QUANTIFY TISSUE COMPRESSION. [0046] Applicant of the present application also owns the following patent applications that were filed on April 9, 2014 and which are each herein incorporated by reference in their respective entireties:

U.S. Patent Application Serial 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;

U.S. Patent Application Serial 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;

U.S. Patent Application Serial No. 14/248,586, entitled DRIVE SYSTEM DECOUPLING ARRANGEMENT FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0305990;

U.S. Patent Application Serial No. 14/248,587, entitled POWERED SURGICAL

STAPLER, now U.S. Patent Application Publication No. 2014/0309665;

U.S. Patent Application Serial No. 14/248,588, entitled POWERED LINEAR SURGICAL STAPLER, now U.S. Patent Application Publication No. 2014/0309666;

U.S. Patent Application Serial No. 14/248,590, entitled MOTOR DRIVEN SURGICAL INSTRUMENTS WITH LOCKABLE DUAL DRIVE SHAFTS, now U.S. Patent Application Publication No. 2014/0305987;

U.S. Patent Application Serial No. 14/248,591, entitled TRANSMISSION

ARRANGEMENT FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0305991;

U.S. Patent Application Serial 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; and

U.S. Patent Application Serial No. 14/248,607, entitled MODULAR MOTOR DRIVEN SURGICAL INSTRUMENTS WITH STATUS INDICATION ARRANGEMENTS, now U.S. Patent Application Publication No. 2014/0305992.

[0047] Applicant of the present application also owns the following patent applications that were filed on March 26, 2014 and are each herein incorporated by reference in their respective entireties: U.S. Patent Application Serial No. 14/226,071, entitled SURGICAL INSTRUMENT CONTROL CIRCUIT HAVING A SAFETY PROCESSOR;

U.S. Patent Application Serial No. 14/226,075, entitled MODULAR POWERED

SURGICAL INSTRUMENT WITH DETACHABLE SHAFT ASSEMBLIES;

U.S. Patent Application Serial No. 14/226,076, entitled POWER MANAGEMENT

THROUGH SEGMENTED CIRCUIT AND VARIABLE VOLTAGE PROTECTION;

U.S. Patent Application Serial No. 14/226,081, entitled SYSTEMS AND METHODS FOR CONTROLLING A SEGMENTED CIRCUIT;

U.S. Patent Application Serial No. 14/226,093, entitled FEEDBACK ALGORITHMS FOR MANUAL BAILOUT SYSTEMS FOR SURGICAL INSTRUMENTS;

U.S. Patent Application Serial No. 14/226,094, entitled VERIFICATION OF NUMBER OF BATTERY EXCHANGES/PROCEDURE COUNT;

U.S. Patent Application Serial No. 14/226,097, entitled SURGICAL INSTRUMENT COMPRISING INTERACTIVE SYSTEMS;

U.S. Patent Application Serial No. 14/226,099, entitled STERILIZATION VERIFICATION CIRCUIT;

U.S. Patent Application Serial No. 14/226,106, entitled POWER MANAGEMENT

CONTROL SYSTEMS FOR SURGICAL INSTRUMENTS;

U.S. Patent Application Serial No. 14/226,111, entitled SURGICAL STAPLING

INSTRUMENT SYSTEM;

U.S. Patent Application Serial No. 14/226,116, entitled SURGICAL INSTRUMENT UTILIZING SENSOR ADAPTATION;

U.S. Patent Application Serial No. 14/226,117, entitled POWER MANAGEMENT

THROUGH SLEEP OPTIONS OF SEGMENTED CIRCUIT AND WAKE UP CONTROL;

U.S. Patent Application Serial No. 14/226,125, entitled SURGICAL INSTRUMENT COMPRISING A ROTATABLE SHAFT;

U.S. Patent Application Serial No. 14/226,126, entitled INTERFACE SYSTEMS FOR USE WITH SURGICAL INSTRUMENTS; and

U.S. Patent Application Serial No. 14/226,133, entitled MODULAR SURGICAL

INSTRUMENT SYSTEM.

[0048] Applicant of the present application also owns the following patent application that was filed on March 7, 2014 and is herein incorporated by reference in its entirety: U.S. Patent Application Serial No. 14/200,111, entitled CONTROL SYSTEMS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0263539.

[0049] Applicant of the present application also owns the following patent applications that were filed on April 16, 2013 and which are each herein incorporated by reference in their respective entireties:

U.S. Provisional Patent Application Serial No. 61/812,365, entitled SURGICAL

INSTRUMENT WITH MULTIPLE FUNCTIONS PERFORMED BY A SINGLE MOTOR;

U.S. Provisional Patent Application Serial No. 61/812,372, entitled SURGICAL

INSTRUMENT WITH MULTIPLE FUNCTIONS PERFORMED BY A SINGLE MOTOR;

U.S. Provisional Patent Application Serial No. 61/812,376, entitled LINEAR CUTTER WITH POWER;

U.S. Provisional Patent Application Serial No. 61/812,382, entitled LINEAR CUTTER WITH MOTOR AND PISTOL GRIP; and

U.S. Provisional Patent Application Serial No. 61/812,385, entitled SURGICAL

INSTRUMENT HANDLE WITH MULTIPLE ACTUATION MOTORS AND MOTOR CONTROL.

[0050] Applicant of the present application also owns the following patent applications that were filed on March 14, 2013 and which are each herein incorporated by reference in their respective entireties:

U.S. Patent Application Serial No. 13/803,053, entitled INTERCHANGEABLE SHAFT ASSEMBLIES FOR USE WITH A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0263564;

U.S. Patent Application Serial No. 13/803,066, entitled DRIVE SYSTEM LOCKOUT ARRANGEMENTS FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0263565;

U.S. Patent Application Serial No. 13/803,086, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, now U.S. Patent Application Publication No. 2014/0263541;

U.S. Patent Application Serial No. 13/803,097, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, now U.S. Patent Application Publication No. 2014/0263542; U.S. Patent Application Serial No. 13/803,117, entitled ARTICULATION CONTROL SYSTEM FOR ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0263553;

U.S. Patent Application Serial No. 13/803,130, entitled DRIVE TRAIN CONTROL

ARRANGEMENTS FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0263543;

U.S. Patent Application Serial No. 13/803,148, entitled MULTI-FUNCTION MOTOR FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0263554;

U.S. Patent Application Serial No. 13/803,159, entitled METHOD AND SYSTEM FOR OPERATING A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No.

2014/0277017;

U.S. Patent Application Serial No. 13/803,193, entitled CONTROL ARRANGEMENTS FOR A DRIVE MEMBER OF A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0263537; and

U.S. Patent Application Serial No. 13/803,210, entitled SENSOR ARRANGEMENTS FOR ABSOLUTE POSITIONING SYSTEM FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0263538.

[0051] Applicant of the present application owns the following patent applications that were filed on March 1, 2013 and which are each herein incorporated by reference in their respective entireties:

U.S. Patent Application Serial No. 13/782,295, entitled ARTICULATABLE SURGICAL INSTRUMENTS WITH CONDUCTIVE PATHWAYS FOR SIGNAL COMMUNICATION, now U.S. Patent Application Publication No. 2014/0246471;

U.S. Patent Application Serial No. 13/782,323, entitled ROTARY POWERED

ARTICULATION JOINTS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0246472;

U.S. Patent Application Serial No. 13/782,338, entitled THUMBWHEEL SWITCH

ARRANGEMENTS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0249557;

U.S. Patent Application Serial No. 13/782,358, entitled JOYSTICK SWITCH

ASSEMBLIES FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0246477; U.S. Patent Application Serial No. 13/782,375, entitled ROTARY POWERED SURGICAL INSTRUMENTS WITH MULTIPLE DEGREES OF FREEDOM, now U.S. Patent Application Publication No. 2014/0246473;

U.S. Patent Application Serial No. 13/782,460, entitled MULTIPLE PROCESSOR MOTOR CONTROL FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Patent Application

Publication No. 2014/0246478;

U.S. Patent Application Serial No. 13/782,481, entitled SENSOR STRAIGHTENED END EFFECTOR DURING REMOVAL THROUGH TROCAR, now U.S. Patent Application

Publication No. 2014/0246479;

U.S. Patent Application Serial No. 13/782,499, entitled ELECTROMECHANICAL

SURGICAL DEVICE WITH SIGNAL RELAY ARRANGEMENT, now U.S. Patent Application Publication No. 2014/0246474;

U.S. Patent Application Serial No. 13/782,518, entitled CONTROL METHODS FOR SURGICAL INSTRUMENTS WITH REMOVABLE FMPLEMENT PORTIONS, now U.S. Patent Application Publication No. 2014/0246475; and

U.S. Patent Application Serial No. 13/782,536, entitled SURGICAL INSTRUMENT SOFT STOP, now U.S. Patent Application Publication No. 2014/0246476.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] FIGS. 1-6 depict a motor-driven surgical cutting and fastening instrument 10 that may or may not be reused. In the illustrated examples, the instrument 10 includes a housing 12 that comprises a handle assembly 14 that is configured to be grasped, manipulated and actuated by the clinician. The housing 12 is configured for operable attachment to an interchangeable shaft assembly 200 that has a surgical end effector 300 operably coupled thereto that is configured to perform one or more surgical tasks or procedures. As the present Detailed Description proceeds, it will be understood that the various unique and novel arrangements of the various forms of interchangeable shaft assemblies disclosed herein also may be effectively employed in connection with robotically-controlled surgical systems. Thus, the term "housing" also may encompass a housing or similar portion of a robotic system that houses or otherwise operably supports at least one drive system that is configured to generate and apply at least one control motion which could be used to actuate the interchangeable shaft assemblies disclosed herein and their respective equivalents. The term "frame" may refer to a portion of a handheld surgical instrument. The term "frame" also may represent a portion of a robotically controlled surgical instrument and/or a portion of the robotic system that may be used to operably control a surgical instrument. For example, the interchangeable shaft assemblies disclosed herein may be employed with various robotic systems, instruments, components and methods disclosed in U.S. Patent Application Serial No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE

DEPLOYMENT ARRANGEMENTS, now U.S. Patent No. 9,072,535. U.S. Patent Application Serial No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Patent No. 9,072,535, is incorporated by reference herein in its entirety.

[0061] The housing 12 depicted in FIGS. 1-3 is shown in connection with an interchangeable shaft assembly 200 that includes an end effector 300 that comprises a surgical cutting and fastening device that is configured to operably support a surgical staple cartridge 304 therein. The housing 12 may be configured for use in connection with interchangeable shaft assemblies that include end effectors that are adapted to support different sizes and types of staple cartridges, have different shaft lengths, sizes, and types, etc. In addition, the housing 12 also may be effectively employed with a variety of other interchangeable shaft assemblies including those assemblies that are configured to apply other motions and forms of energy such as, for example, radio frequency (RF) energy, ultrasonic energy and/or motion to end effector arrangements adapted for use in connection with various surgical applications and procedures. Furthermore, the end effectors, shaft assemblies, handles, surgical instruments, and/or surgical instrument systems can utilize any suitable fastener, or fasteners, to fasten tissue. For instance, a fastener cartridge comprising a plurality of fasteners removably stored therein can be removably inserted into and/or attached to the end effector of a shaft assembly. [0062] FIG. 1 illustrates the surgical instrument 10 with an interchangeable shaft assembly 200 operably coupled thereto. FIGS. 2 and 3 illustrate attachment of the interchangeable shaft assembly 200 to the housing 12 or handle assembly 14. As shown in FIG. 4, the handle assembly 14 may comprise a pair of interconnectable handle housing segments 16 and 18 that may be interconnected by screws, snap features, adhesive, etc. In the illustrated arrangement, the handle housing segments 16, 18 cooperate to form a pistol grip portion 19 that can be gripped and manipulated by the clinician. As will be discussed in further detail below, the handle assembly 14 operably supports a plurality of drive systems therein that are configured to generate and apply various control motions to corresponding portions of the interchangeable shaft assembly that is operably attached thereto.

[0063] Referring now to FIG. 4, the handle assembly 14 may further include a frame 20 that operably supports a plurality of drive systems. For example, the frame 20 can operably support a "first" or closure drive system, generally designated as 30, which may be employed to apply closing and opening motions to the interchangeable shaft assembly 200 that is operably attached or coupled thereto. In at least one form, the closure drive system 30 may include an actuator in the form of a closure trigger 32 that is pivotally supported by the frame 20. More specifically, as illustrated in FIG. 4, the closure trigger 32 is pivotally coupled to the housing 14 by a pin 33. Such arrangement enables the closure trigger 32 to be manipulated by a clinician such that when the clinician grips the pistol grip portion 19 of the handle assembly 14, the closure trigger 32 may be easily pivoted from a starting or "unactuated" position to an "actuated" position and more particularly to a fully compressed or fully actuated position. The closure trigger 32 may be biased into the unactuated position by spring or other biasing arrangement (not shown). In various forms, the closure drive system 30 further includes a closure linkage assembly 34 that is pivotally coupled to the closure trigger 32. As shown in FIG. 4, the closure linkage assembly 34 may include a first closure link 36 and a second closure link 38 that are pivotally coupled to the closure trigger 32 by a pin 35. The second closure link 38 also may be referred to herein as an "attachment member" and include a transverse attachment pin 37.

[0064] Still referring to FIG. 4, it can be observed that the first closure link 36 may have a locking wall or end 39 thereon that is configured to cooperate with a closure release assembly 60 that is pivotally coupled to the frame 20. In at least one form, the closure release assembly 60 may comprise a release button assembly 62 that has a distally protruding locking pawl 64 formed thereon. The release button assembly 62 may be pivoted in a counterclockwise direction by a release spring (not shown). As the clinician depresses the closure trigger 32 from its unactuated position towards the pistol grip portion 19 of the handle assembly 14, the first closure link 36 pivots upward to a point wherein the locking pawl 64 drops into retaining engagement with the locking wall 39 on the first closure link 36 thereby preventing the closure trigger 32 from returning to the unactuated position. See FIG. 18. Thus, the closure release assembly 60 serves to lock the closure trigger 32 in the fully actuated position. When the clinician desires to unlock the closure trigger 32 to permit it to be biased to the unactuated position, the clinician simply pivots the closure release button assembly 62 such that the locking pawl 64 is moved out of engagement with the locking wall 39 on the first closure link 36. When the locking pawl 64 has been moved out of engagement with the first closure link 36, the closure trigger 32 may pivot back to the unactuated position. Other closure trigger locking and release arrangements also may be employed.

[0065] Further to the above, FIGS. 13-15 illustrate the closure trigger 32 in its unactuated position which is associated with an open, or undamped, configuration of the shaft assembly 200 in which tissue can be positioned between the jaws of the shaft assembly 200. FIGS. 16-18 illustrate the closure trigger 32 in its actuated position which is associated with a closed, or clamped,

configuration of the shaft assembly 200 in which tissue is clamped between the jaws of the shaft assembly 200. Upon comparing FIGS. 14 and 17, the reader will appreciate that, when the closure trigger 32 is moved from its unactuated position (FIG. 14) to its actuated position (FIG. 17), the closure release button 62 is pivoted between a first position (FIG. 14) and a second position (FIG. 17). The rotation of the closure release button 62 can be referred to as being an upward rotation; however, at least a portion of the closure release button 62 is being rotated toward the circuit board 100. Referring to FIG. 4, the closure release button 62 can include an arm 61 extending therefrom and a magnetic element 63, such as a permanent magnet, for example, mounted to the arm 61. When the closure release button 62 is rotated from its first position to its second position, the magnetic element 63 can move toward the circuit board 100. The circuit board 100 can include at least one sensor configured to detect the movement of the magnetic element 63. In at least one aspect, a magnetic field sensor 65, for example, can be mounted to the bottom surface of the circuit board 100. The magnetic field sensor 65 can be configured to detect changes in a magnetic field surrounding the magnetic field sensor 65 caused by the movement of the magnetic element 63. The magnetic field sensor 65 can be in signal communication with a microcontroller 1500 (FIG. 19), for example, which can determine whether the closure release button 62 is in its first position, which is associated with the unactuated position of the closure trigger 32 and the open configuration of the end effector, its second position, which is associated with the actuated position of the closure trigger 32 and the closed configuration of the end effector, and/or any position between the first position and the second position.

[0066] As used throughout the present disclosure, a magnetic field sensor may be a Hall effect sensor, search coil, fluxgate, optically pumped, nuclear precession, SQUID, Hall-effect, anisotropic magnetoresi stance, giant magnetoresi stance, magnetic tunnel junctions, giant magnetoimpedance, magnetostrictive/piezoelectric composites, magnetodiode, magnetotransistor, fiber optic, magnetooptic, and microelectromechanical systems-based magnetic sensors, among others.

[0067] In at least one form, the handle assembly 14 and the frame 20 may operably support another drive system referred to herein as a firing drive system 80 that is configured to apply firing motions to corresponding portions of the interchangeable shaft assembly attached thereto. The firing drive system may 80 also be referred to herein as a "second drive system". The firing drive system 80 may employ an electric motor 82, located in the pistol grip portion 19 of the handle assembly 14. In various forms, the motor 82 may be a DC brushed driving motor having a maximum rotation of, approximately, 25,000 RPM, for example. In other arrangements, the motor 82 may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. The motor 82 may be powered by a power source 90 that in one form may comprise a removable power pack 92. As shown in FIG. 4, for example, the power pack 92 may comprise a proximal housing portion 94 that is configured for attachment to a distal housing portion 96. The proximal housing portion 94 and the distal housing portion 96 are configured to operably support a plurality of batteries 98 therein. Batteries 98 may each comprise, for example, a Lithium Ion ("LI") or other suitable battery. The distal housing portion 96 is configured for removable operable attachment to a control circuit board assembly 100 which is also operably coupled to the motor 82. A number of batteries 98 may be connected in series may be used as the power source for the surgical instrument 10. In addition, the power source 90 may be replaceable and/or rechargeable.

[0068] As outlined above with respect to other various forms, the electric motor 82 can include a rotatable shaft (not shown) that operably interfaces with a gear reducer assembly 84 that is mounted in meshing engagement with a with a set, or rack, of drive teeth 122 on a longitudinally-movable drive member 120. In use, a voltage polarity provided by the power source 90 can operate the electric motor 82 in a clockwise direction wherein the voltage polarity applied to the electric motor by the battery can be reversed in order to operate the electric motor 82 in a counter-clockwise direction. When the electric motor 82 is rotated in one direction, the drive member 120 will be axially driven in the distal direction "DD". When the motor 82 is driven in the opposite rotary direction, the drive member 120 will be axially driven in a proximal direction "PD". The handle assembly 14 can include a switch which can be configured to reverse the polarity applied to the electric motor 82 by the power source 90. As with the other forms described herein, the handle assembly 14 can also include a sensor that is configured to detect the position of the drive member 120 and/or the direction in which the drive member 120 is being moved.

[0069] Actuation of the motor 82 can be controlled by a firing trigger 130 that is pivotally supported on the handle assembly 14. The firing trigger 130 may be pivoted between an unactuated position and an actuated position. The firing trigger 130 may be biased into the unactuated position by a spring 132 or other biasing arrangement such that when the clinician releases the firing trigger 130, it may be pivoted or otherwise returned to the unactuated position by the spring 132 or biasing arrangement. In at least one form, the firing trigger 130 can be positioned "outboard" of the closure trigger 32 as was discussed above. In at least one form, a firing trigger safety button 134 may be pivotally mounted to the closure trigger 32 by pin 35. The safety button 134 may be positioned between the firing trigger 130 and the closure trigger 32 and have a pivot arm 136 protruding therefrom. See FIG. 4. When the closure trigger 32 is in the unactuated position, the safety button 134 is contained in the handle assembly 14 where the clinician cannot readily access it and move it between a safety position preventing actuation of the firing trigger 130 and a firing position wherein the firing trigger 130 may be fired. As the clinician depresses the closure trigger 32, the safety button 134 and the firing trigger 130 pivot down wherein they can then be manipulated by the clinician.

[0070] As discussed above, the handle assembly 14 can include a closure trigger 32 and a firing trigger 130. Referring to FIGS. 14-18A, the firing trigger 130 can be pivotably mounted to the closure trigger 32. The closure trigger 32 can include an arm 31 extending therefrom and the firing trigger 130 can be pivotably mounted to the arm 31 about a pivot pin 33. When the closure trigger 32 is moved from its unactuated position (FIG. 14) to its actuated position (FIG. 17), the firing trigger 130 can descend downwardly, as outlined above. After the safety button 134 has been moved to its firing position, referring primarily to FIG. 18 A, the firing trigger 130 can be depressed to operate the motor of the surgical instrument firing system. In various instances, the handle assembly 14 can include a tracking system, such as system 800, for example, configured to determine the position of the closure trigger 32 and/or the position of the firing trigger 130. With primary reference to FIGS. 14, 17, and 18 A, the tracking system 800 can include a magnetic element, such as permanent magnet 802, for example, which is mounted to an arm 801 extending from the firing trigger 130. The tracking system 800 can comprise one or more sensors, such as a first magnetic field sensor 803 and a second magnetic field sensor 804, for example, which can be configured to track the position of the magnet 802.

[0071] Upon comparing FIGS. 14 and 17, the reader will appreciate that, when the closure trigger 32 is moved from its unactuated position to its actuated position, the magnet 802 can move between a first position adjacent the first magnetic field sensor 803 and a second position adjacent the second magnetic field sensor 804.

[0072] Upon comparing FIGS. 17 and 18 A, the reader will further appreciate that, when the firing trigger 130 is moved from an unfired position (FIG. 17) to a fired position (FIG. 18A), the magnet

802 can move relative to the second magnetic field sensor 804. The sensors 803 and 804 can track the movement of the magnet 802 and can be in signal communication with a microcontroller on the circuit board 100. With data from the first sensor 803 and/or the second sensor 804, the

microcontroller can determine the position of the magnet 802 along a predefined path and, based on that position, the microcontroller can determine whether the closure trigger 32 is in its unactuated position, its actuated position, or a position therebetween. Similarly, with data from the first sensor

803 and/or the second sensor 804, the microcontroller can determine the position of the magnet 802 along a predefined path and, based on that position, the microcontroller can determine whether the firing trigger 130 is in its unfired position, its fully fired position, or a position therebetween.

[0073] As indicated above, in at least one form, the longitudinally movable drive member 120 has a rack of teeth 122 formed thereon for meshing engagement with a corresponding drive gear 86 of the gear reducer assembly 84. At least one form also includes a manually-actuatable "bailout" assembly 140 that is configured to enable the clinician to manually retract the longitudinally movable drive member 120 should the motor 82 become disabled. The bailout assembly 140 may include a lever or bailout handle assembly 142 that is configured to be manually pivoted into ratcheting engagement with teeth 124 also provided in the drive member 120. Thus, the clinician can manually retract the drive member 120 by using the bailout handle assembly 142 to ratchet the drive member 120 in the proximal direction "PD". U.S. Patent Application Publication No.

2010/0089970, now U.S. Patent No. 8,608,045, discloses bailout arrangements and other components, arrangements and systems that also may be employed with the various instruments disclosed herein. U.S. Patent Application Serial No. 12/249,117, entitled POWERED SURGICAL CUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM, U.S. Patent Application Publication No. 2010/0089970, now U.S. Patent No. 8,608,045, is hereby incorporated by reference in its entirety.

[0074] Turning now to FIGS. 1 and 7, the interchangeable shaft assembly 200 includes a surgical end effector 300 that comprises an elongated channel 302 that is configured to operably support a staple cartridge 304 therein. The end effector 300 may further include an anvil 306 that is pivotally supported relative to the elongated channel 302. The interchangeable shaft assembly 200 may further include an articulation joint 270 and an articulation lock 350 (FIG. 8) which can be configured to releasably hold the end effector 300 in a desired position relative to a shaft axis SA- SA. Details regarding the construction and operation of the end effector 300, the articulation joint 270 and the articulation lock 350 are set forth in U.S. Patent Application Serial No. 13/803,086, filed March 14, 2013, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, now U.S. Patent Application Publication No. 2014/0263541. The entire disclosure of U.S. Patent Application Serial No. 13/803,086, filed March 14, 2013, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, now U.S. Patent Application Publication No. 2014/0263541, is hereby incorporated by reference herein. As shown in FIGS. 7 and 8, the interchangeable shaft assembly 200 can further include a proximal housing or nozzle 201 comprised of nozzle portions 202 and 203. The interchangeable shaft assembly 200 can further include a closure tube 260 which can be utilized to close and/or open the anvil 306 of the end effector 300. Primarily referring now to FIGS. 8 and 9, the shaft assembly 200 can include a spine 210 which can be configured to fixably support a shaft frame portion 212 of the articulation lock 350. See FIG. 8. The spine 210 can be configured to, one, slidably support a firing member 220 therein and, two, slidably support the closure tube 260 which extends around the spine 210. The spine 210 can also be configured to slidably support a proximal articulation driver 230. The articulation driver 230 has a distal end 231 that is configured to operably engage the articulation lock 350. The articulation lock 350 interfaces with an articulation frame 352 that is adapted to operably engage a drive pin (not shown) on the end effector frame (not shown). As indicated above, further details regarding the operation of the articulation lock 350 and the articulation frame may be found in U.S. Patent Application Serial No. 13/803,086, now U.S. Patent Application Publication No. 2014/0263541. In various circumstances, the spine 210 can comprise a proximal end 21 1 which is rotatably supported in a chassis 240. In one arrangement, for example, the proximal end 211 of the spine 210 has a thread 214 formed thereon for threaded attachment to a spine bearing 216 configured to be supported within the chassis 240. See FIG. 7. Such an arrangement facilitates rotatable attachment of the spine 210 to the chassis 240 such that the spine 210 may be selectively rotated about a shaft axis SA-SA relative to the chassis 240.

[0075] Referring primarily to FIG. 7, the interchangeable shaft assembly 200 includes a closure shuttle 250 that is slidably supported within the chassis 240 such that it may be axially moved relative thereto. As shown in FIGS. 3 and 7, the closure shuttle 250 includes a pair of proximally- protruding hooks 252 that are configured for attachment to the attachment pin 37 that is attached to the second closure link 38 as will be discussed in further detail below. A proximal end 261 of the closure tube 260 is coupled to the closure shuttle 250 for relative rotation thereto. For example, a U shaped connector 263 is inserted into an annular slot 262 in the proximal end 261 of the closure tube 260 and is retained within vertical slots 253 in the closure shuttle 250. See FIG. 7. Such an arrangement serves to attach the closure tube 260 to the closure shuttle 250 for axial travel therewith while enabling the closure tube 260 to rotate relative to the closure shuttle 250 about the shaft axis SA-SA. A closure spring 268 is journaled on the closure tube 260 and serves to bias the closure tube 260 in the proximal direction "PD" which can serve to pivot the closure trigger into the unactuated position when the shaft assembly is operably coupled to the handle assembly 14.

[0076] In at least one form, the interchangeable shaft assembly 200 may further include an articulation joint 270. Other interchangeable shaft assemblies, however, may not be capable of articulation. As shown in FIG. 7, for example, the articulation joint 270 includes a double pivot closure sleeve assembly 271. According to various forms, the double pivot closure sleeve assembly 271 includes an end effector closure sleeve assembly 272 having upper and lower distally projecting tangs 273, 274. An end effector closure sleeve assembly 272 includes a horseshoe aperture 275 and a tab 276 for engaging an opening tab on the anvil 306 in the various manners described in U.S. Patent Application Serial No. 13/803,086, filed March 14, 2013, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, now U.S. Patent Application Publication No. 2014/0263541, which has been incorporated by reference herein. As described in further detail therein, the horseshoe aperture 275 and tab 276 engage a tab on the anvil when the anvil 306 is opened. An upper double pivot link 277 includes upwardly projecting distal and proximal pivot pins that engage respectively an upper distal pin hole in the upper proximally projecting tang 273 and an upper proximal pin hole in an upper distally projecting tang 264 on the closure tube 260. A lower double pivot link 278 includes upwardly projecting distal and proximal pivot pins that engage respectively a lower distal pin hole in the lower proximally projecting tang 274 and a lower proximal pin hole in the lower distally projecting tang 265. See also FIG. 8. [0077] In use, the closure tube 260 is translated distally (direction "DD") to close the anvil 306, for example, in response to the actuation of the closure trigger 32. The anvil 306 is closed by distally translating the closure tube 260 and thus the shaft closure sleeve assembly 272, causing it to strike a proximal surface on the anvil 360 in the manner described in the aforementioned reference U.S. Patent Application Serial No. 13/803,086, now U.S. Patent Application Publication No.

2014/0263541. As was also described in detail in that reference, the anvil 306 is opened by proximally translating the closure tube 260 and the shaft closure sleeve assembly 272, causing tab 276 and the horseshoe aperture 275 to contact and push against the anvil tab to lift the anvil 306. In the anvil-open position, the shaft closure tube 260 is moved to its proximal position.

[0078] As indicated above, the surgical instrument 10 may further include an articulation lock 350 of the types and construction described in further detail in U.S. Patent Application Serial No.

13/803,086, now U.S. Patent Application Publication No. 2014/0263541, which can be configured and operated to selectively lock the end effector 300 in position. Such arrangement enables the end effector 300 to be rotated, or articulated, relative to the shaft closure tube 260 when the articulation lock 350 is in its unlocked state. In such an unlocked state, the end effector 300 can be positioned and pushed against soft tissue and/or bone, for example, surrounding the surgical site within the patient in order to cause the end effector 300 to articulate relative to the closure tube 260. The end effector 300 also may be articulated relative to the closure tube 260 by an articulation driver 230.

[0079] As was also indicated above, the interchangeable shaft assembly 200 further includes a firing member 220 that is supported for axial travel within the shaft spine 210. The firing member 220 includes an intermediate firing shaft portion 222 that is configured for attachment to a distal cutting portion or knife bar 280. The firing member 220 also may be referred to herein as a "second shaft" and/or a "second shaft assembly". As shown in FIGS. 8 and 9, the intermediate firing shaft portion 222 may include a longitudinal slot 223 in the distal end thereof which can be configured to receive a tab 284 on the proximal end 282 of the distal knife bar 280. The longitudinal slot 223 and the proximal end 282 can be sized and configured to permit relative movement therebetween and can comprise a slip joint 286. The slip joint 286 can permit the intermediate firing shaft portion 222 of the firing drive 220 to be moved to articulate the end effector 300 without moving, or at least substantially moving, the knife bar 280. Once the end effector 300 has been suitably oriented, the intermediate firing shaft portion 222 can be advanced distally until a proximal sidewall of the longitudinal slot 223 comes into contact with the tab 284 in order to advance the knife bar 280 and fire the staple cartridge positioned within the channel 302 As can be further seen in FIGS. 8 and 9, the shaft spine 210 has an elongate opening or window 213 therein to facilitate assembly and insertion of the intermediate firing shaft portion 222 into the shaft frame 210. Once the

intermediate firing shaft portion 222 has been inserted therein, a top frame segment 215 may be engaged with the shaft frame 212 to enclose the intermediate firing shaft portion 222 and knife bar 280 therein. Further description of the operation of the firing member 220 may be found in U.S. Patent Application Serial No. 13/803,086, now U.S. Patent Application Publication No.

2014/0263541.

[0080] Further to the above, the shaft assembly 200 can include a clutch assembly 400 which can be configured to selectively and releasably couple the articulation driver 230 to the firing member 220. In one form, the clutch assembly 400 includes a lock collar, or sleeve 402, positioned around the firing member 220 wherein the lock sleeve 402 can be rotated between an engaged position in which the lock sleeve 402 couples the articulation driver 360 to the firing member 220 and a disengaged position in which the articulation driver 360 is not operably coupled to the firing member 200. When lock sleeve 402 is in its engaged position, distal movement of the firing member 220 can move the articulation driver 360 distally and, correspondingly, proximal movement of the firing member 220 can move the articulation driver 230 proximally. When lock sleeve 402 is in its disengaged position, movement of the firing member 220 is not transmitted to the articulation driver 230 and, as a result, the firing member 220 can move independently of the articulation driver 230. In various circumstances, the articulation driver 230 can be held in position by the articulation lock 350 when the articulation driver 230 is not being moved in the proximal or distal directions by the firing member 220.

[0081] Referring primarily to FIG. 9, the lock sleeve 402 can comprise a cylindrical, or an at least substantially cylindrical, body including a longitudinal aperture 403 defined therein configured to receive the firing member 220. The lock sleeve 402 can comprise diametrically-opposed, inwardly- facing lock protrusions 404 and an outwardly-facing lock member 406. The lock protrusions 404 can be configured to be selectively engaged with the firing member 220. More particularly, when the lock sleeve 402 is in its engaged position, the lock protrusions 404 are positioned within a drive notch 224 defined in the firing member 220 such that a distal pushing force and/or a proximal pulling force can be transmitted from the firing member 220 to the lock sleeve 402. When the lock sleeve 402 is in its engaged position, the second lock member 406 is received within a drive notch 232 defined in the articulation driver 230 such that the distal pushing force and/or the proximal pulling force applied to the lock sleeve 402 can be transmitted to the articulation driver 230. In effect, the firing member 220, the lock sleeve 402, and the articulation driver 230 will move together when the lock sleeve 402 is in its engaged position. On the other hand, when the lock sleeve 402 is in its disengaged position, the lock protrusions 404 may not be positioned within the drive notch 224 of the firing member 220 and, as a result, a distal pushing force and/or a proximal pulling force may not be transmitted from the firing member 220 to the lock sleeve 402.

Correspondingly, the distal pushing force and/or the proximal pulling force may not be transmitted to the articulation driver 230. In such circumstances, the firing member 220 can be slid proximally and/or distally relative to the lock sleeve 402 and the proximal articulation driver 230.

[0082] As shown in FIGS. 8-12, the shaft assembly 200 further includes a switch drum 500 that is rotatably received on the closure tube 260. The switch drum 500 comprises a hollow shaft segment 502 that has a shaft boss 504 formed thereon for receive an outwardly protruding actuation pin 410 therein. In various circumstances, the actuation pin 410 extends through a slot 267 into a longitudinal slot 408 provided in the lock sleeve 402 to facilitate axial movement of the lock sleeve 402 when it is engaged with the articulation driver 230. A rotary torsion spring 420 is configured to engage the boss 504 on the switch drum 500 and a portion of the nozzle housing 203 as shown in FIG. 10 to apply a biasing force to the switch drum 500. The switch drum 500 can further comprise at least partially circumferential openings 506 defined therein which, referring to FIGS. 5 and 6, can be configured to receive circumferential mounts 204, 205 extending from the nozzle halves 202, 203 and permit relative rotation, but not translation, between the switch drum 500 and the proximal nozzle 201. As shown in those Figures, the mounts 204 and 205 also extend through openings 266 in the closure tube 260 to be seated in recesses 209 in the shaft spine 210. However, rotation of the nozzle 201 to a point where the mounts 204, 205 reach the end of their respective slots 506 in the switch drum 500 will result in rotation of the switch drum 500 about the shaft axis SA-SA.

Rotation of the switch drum 500 will ultimately result in the rotation of the actuation pin 410 and the lock sleeve 402 between its engaged and disengaged positions. Thus, in essence, the nozzle 201 may be employed to operably engage and disengage the articulation drive system with the firing drive system in the various manners described in further detail in U.S. Patent Application Serial No. 13/803,086, now U.S. Patent Application Publication No. 2014/0263541.

[0083] As also illustrated in FIGS. 8-12, the shaft assembly 200 can comprise a slip ring assembly 600 which can be configured to conduct electrical power to and/or from the end effector 300 and/or communicate signals to and/or from the end effector 300, for example. The slip ring assembly 600 can comprise a proximal connector flange 604 mounted to a chassis flange 242 extending from the chassis 240 and a distal connector flange 601 positioned within a slot defined in the shaft housings 202, 203. The proximal connector flange 604 can comprise a first face and the distal connector flange 601 can comprise a second face which is positioned adjacent to and movable relative to the first face. The distal connector flange 601 can rotate relative to the proximal connector flange 604 about the shaft axis SA-SA. The proximal connector flange 604 can comprise a plurality of concentric, or at least substantially concentric, conductors 602 defined in the first face thereof. A connector 607 can be mounted on the proximal side of the connector flange 601 and may have a plurality of contacts (not shown) wherein each contact corresponds to and is in electrical contact with one of the conductors 602. Such an arrangement permits relative rotation between the proximal connector flange 604 and the distal connector flange 601 while maintaining electrical contact therebetween. The proximal connector flange 604 can include an electrical connector 606 which can place the conductors 602 in signal communication with a shaft circuit board 610 mounted to the shaft chassis 240, for example. In at least one instance, a wiring harness comprising a plurality of conductors can extend between the electrical connector 606 and the shaft circuit board 610. The electrical connector 606 may extend proximally through a connector opening 243 defined in the chassis mounting flange 242. See FIG. 7. U.S. Patent Application Serial No. 13/800,067, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on March 13, 2013, now U.S. Patent Application Publication No. 2014/0263552, is incorporated by reference in its entirety. U.S. Patent Application Serial No. 13/800,025, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on March 13, 2013, now U.S. Patent Application Publication No. 2014/0263551, is incorporated by reference in its entirety. Further details regarding slip ring assembly 600 may be found in U.S. Patent Application Serial No. 13/803,086, now U.S. Patent Application Publication No. 2014/0263541.

[0084] As discussed above, the shaft assembly 200 can include a proximal portion which is fixably mounted to the handle assembly 14 and a distal portion which is rotatable about a longitudinal axis. The rotatable distal shaft portion can be rotated relative to the proximal portion about the slip ring assembly 600, as discussed above. The distal connector flange 601 of the slip ring assembly 600 can be positioned within the rotatable distal shaft portion. Moreover, further to the above, the switch drum 500 can also be positioned within the rotatable distal shaft portion. When the rotatable distal shaft portion is rotated, the distal connector flange 601 and the switch drum 500 can be rotated synchronously with one another. In addition, the switch drum 500 can be rotated between a first position and a second position relative to the distal connector flange 601. When the switch drum 500 is in its first position, the articulation drive system may be operably disengaged from the firing drive system and, thus, the operation of the firing drive system may not articulate the end effector 300 of the shaft assembly 200. When the switch drum 500 is in its second position, the articulation drive system may be operably engaged with the firing drive system and, thus, the operation of the firing drive system may articulate the end effector 300 of the shaft assembly 200. When the switch drum 500 is moved between its first position and its second position, the switch drum 500 is moved relative to distal connector flange 601. In various instances, the shaft assembly 200 can comprise at least one sensor configured to detect the position of the switch drum 500. Turning now to FIGS. 11 and 12, the distal connector flange 601 can comprise a magnetic field sensor 605, for example, and the switch drum 500 can comprise a magnetic element, such as permanent magnet 505, for example. The magnetic field sensor 605 can be configured to detect the position of the permanent magnet 505. When the switch drum 500 is rotated between its first position and its second position, the permanent magnet 505 can move relative to the magnetic field sensor 605. In various instances, magnetic field sensor 605 can detect changes in a magnetic field created when the permanent magnet 505 is moved. The magnetic field sensor 605 can be in signal communication with the shaft circuit board 610 and/or the handle circuit board 100, for example. Based on the signal from the magnetic field sensor 605, a microcontroller on the shaft circuit board 610 and/or the handle circuit board 100 can determine whether the articulation drive system is engaged with or disengaged from the firing drive system.

[0085] Referring again to FIGS. 3 and 7, the chassis 240 includes at least one, and preferably two, tapered attachment portions 244 formed thereon that are adapted to be received within

corresponding dovetail slots 702 formed within a distal attachment flange portion 700 of the frame 20. Each dovetail slot 702 may be tapered or, stated another way, be somewhat V-shaped to seatingly receive the attachment portions 244 therein. As can be further seen in FIGS. 3 and 7, a shaft attachment lug 226 is formed on the proximal end of the intermediate firing shaft 222. As will be discussed in further detail below, when the interchangeable shaft assembly 200 is coupled to the handle assembly 14, the shaft attachment lug 226 is received in a firing shaft attachment cradle 126 formed in the distal end 125 of the longitudinal drive member 120 as shown in FIGS. 3 and 6, for example.

[0086] Various shaft assemblies employ a latch system 710 for removably coupling the shaft assembly 200 to the housing 12 and more specifically to the frame 20. As shown in FIG. 7, for example, in at least one form, the latch system 710 includes a lock member or lock yoke 712 that is movably coupled to the chassis 240. In the illustrated example, for example, the lock yoke 712 has a U-shape with two spaced downwardly extending legs 714. The legs 714 each have a pivot lug 715 formed thereon that are adapted to be received in corresponding holes 245 formed in the chassis 240. Such arrangement facilitates pivotal attachment of the lock yoke 712 to the chassis 240. The lock yoke 712 may include two proximally protruding lock lugs 716 that are configured for releasable engagement with corresponding lock detents or grooves 704 in the distal attachment flange 700 of the frame 20. See FIG. 3. In various forms, the lock yoke 712 is biased in the proximal direction by spring or biasing member (not shown). Actuation of the lock yoke 712 may be accomplished by a latch button 722 that is slidably mounted on a latch actuator assembly 720 that is mounted to the chassis 240. The latch button 722 may be biased in a proximal direction relative to the lock yoke 712. As will be discussed in further detail below, the lock yoke 712 may be moved to an unlocked position by biasing the latch button the in distal direction which also causes the lock yoke 712 to pivot out of retaining engagement with the distal attachment flange 700 of the frame 20. When the lock yoke 712 is in "retaining engagement" with the distal attachment flange 700 of the frame 20, the lock lugs 716 are retainingly seated within the corresponding lock detents or grooves 704 in the distal attachment flange 700.

[0087] When employing an interchangeable shaft assembly that includes an end effector of the type described herein that is adapted to cut and fasten tissue, as well as other types of end effectors, it may be desirable to prevent inadvertent detachment of the interchangeable shaft assembly from the housing during actuation of the end effector. For example, in use the clinician may actuate the closure trigger 32 to grasp and manipulate the target tissue into a desired position. Once the target tissue is positioned within the end effector 300 in a desired orientation, the clinician may then fully actuate the closure trigger 32 to close the anvil 306 and clamp the target tissue in position for cutting and stapling. In that instance, the first drive system 30 has been fully actuated. After the target tissue has been clamped in the end effector 300, it may be desirable to prevent the inadvertent detachment of the shaft assembly 200 from the housing 12. One form of the latch system 710 is configured to prevent such inadvertent detachment.

[0088] As can be most particularly seen in FIG. 7, the lock yoke 712 includes at least one and preferably two lock hooks 718 that are adapted to contact corresponding lock lug portions 256 that are formed on the closure shuttle 250. Referring to FIGS. 13-15, when the closure shuttle 250 is in an unactuated position (i.e., the first drive system 30 is unactuated and the anvil 306 is open), the lock yoke 712 may be pivoted in a distal direction to unlock the interchangeable shaft assembly 200 from the housing 12. When in that position, the lock hooks 718 do not contact the lock lug portions 256 on the closure shuttle 250. However, when the closure shuttle 250 is moved to an actuated position (i.e., the first drive system 30 is actuated and the anvil 306 is in the closed position), the lock yoke 712 is prevented from being pivoted to an unlocked position. See FIGS. 16-18. Stated another way, if the clinician were to attempt to pivot the lock yoke 712 to an unlocked position or, for example, the lock yoke 712 was in advertently bumped or contacted in a manner that might otherwise cause it to pivot distally, the lock hooks 718 on the lock yoke 712 will contact the lock lug portions 256 on the closure shuttle 250 and prevent movement of the lock yoke 712 to an unlocked position.

[0089] Attachment of the interchangeable shaft assembly 200 to the handle assembly 14 will now be described with reference to FIG. 3. To commence the coupling process, the clinician may position the chassis 240 of the interchangeable shaft assembly 200 above or adjacent to the distal attachment flange 700 of the frame 20 such that the tapered attachment portions 244 formed on the chassis 240 are aligned with the dovetail slots 702 in the frame 20. The clinician may then move the shaft assembly 200 along an installation axis IA that is perpendicular to the shaft axis SA-SA to seat the attachment portions 244 in "operable engagement" with the corresponding dovetail receiving slots 702. In doing so, the shaft attachment lug 226 on the intermediate firing shaft 222 will also be seated in the cradle 126 in the longitudinally movable drive member 120 and the portions of pin 37 on the second closure link 38 will be seated in the corresponding hooks 252 in the closure yoke 250. As used herein, the term "operable engagement" in the context of two components means that the two components are sufficiently engaged with each other so that upon application of an actuation motion thereto, the components may carry out their intended action, function and/or procedure.

[0090] As discussed above, at least five systems of the interchangeable shaft assembly 200 can be operably coupled with at least five corresponding systems of the handle assembly 14. A first system can comprise a frame system which couples and/or aligns the frame or spine of the shaft assembly 200 with the frame 20 of the handle assembly 14. Another system can comprise a closure drive system 30 which can operably connect the closure trigger 32 of the handle assembly 14 and the closure tube 260 and the anvil 306 of the shaft assembly 200. As outlined above, the closure tube attachment yoke 250 of the shaft assembly 200 can be engaged with the pin 37 on the second closure link 38. Another system can comprise the firing drive system 80 which can operably connect the firing trigger 130 of the handle assembly 14 with the intermediate firing shaft 222 of the shaft assembly 200.

[0091] As outlined above, the shaft attachment lug 226 can be operably connected with the cradle 126 of the longitudinal drive member 120. Another system can comprise an electrical system which can signal to a controller in the handle assembly 14, such as microcontroller, for example, that a shaft assembly, such as shaft assembly 200, for example, has been operably engaged with the handle assembly 14 and/or, two, conduct power and/or communication signals between the shaft assembly 200 and the handle assembly 14. For instance, the shaft assembly 200 can include an electrical connector 1410 that is operably mounted to the shaft circuit board 610. The electrical connector 1410 is configured for mating engagement with a corresponding electrical connector 1400 on the handle control board 100. Further details regaining the circuitry and control systems may be found in U.S. Patent Application Serial No. 13/803,086, now U.S. Patent Application Publication No. 2014/0263541, the entire disclosure of which was previously incorporated by reference herein. The fifth system may consist of the latching system for releasably locking the shaft assembly 200 to the handle assembly 14.

[0092] Referring again to FIGS. 2 and 3, the handle assembly 14 can include an electrical connector 1400 comprising a plurality of electrical contacts. Turning now to FIG. 19, the electrical connector 1400 can comprise a first contact 1401a, a second contact 1401b, a third contact 1401c, a fourth contact 1401d, a fifth contact 1401e, and a sixth contact 1401f, for example. While the illustrated example utilizes six contacts, other examples are envisioned which may utilize more than six contacts or less than six contacts.

[0093] As illustrated in FIG. 19, the first contact 1401a can be in electrical communication with a transistor 1408, contacts 1401b-1401e can be in electrical communication with a microcontroller 1500, and the sixth contact 1401f can be in electrical communication with a ground. In certain circumstances, one or more of the electrical contacts 1401b-1401e may be in electrical

communication with one or more output channels of the microcontroller 1500 and can be energized, or have a voltage potential applied thereto, when the handle assembly 14 is in a powered state. In some circumstances, one or more of the electrical contacts 1401b-1401e may be in electrical communication with one or more input channels of the microcontroller 1500 and, when the handle assembly 14 is in a powered state, the microcontroller 1500 can be configured to detect when a voltage potential is applied to such electrical contacts. When a shaft assembly, such as shaft assembly 200, for example, is assembled to the handle assembly 14, the electrical contacts 1401a- 1401f may not communicate with each other. When a shaft assembly is not assembled to the handle assembly 14, however, the electrical contacts 140 la- 140 If of the electrical connector 1400 may be exposed and, in some circumstances, one or more of the contacts 1401a-1401f may be accidentally placed in electrical communication with each other. Such circumstances can arise when one or more of the contacts 140 la- 140 If come into contact with an electrically conductive material, for example. When this occurs, the microcontroller 1500 can receive an erroneous input and/or the shaft assembly 200 can receive an erroneous output, for example. To address this issue, in various circumstances, the handle assembly 14 may be unpowered when a shaft assembly, such as shaft assembly 200, for example, is not attached to the handle assembly 14.

[0094] In other circumstances, the handle assembly 14 can be powered when a shaft assembly, such as shaft assembly 200, for example, is not attached thereto. In such circumstances, the

microcontroller 1500 can be configured to ignore inputs, or voltage potentials, applied to the contacts in electrical communication with the microcontroller 1500, i.e., contacts 1401b-1401e, for example, until a shaft assembly is attached to the handle assembly 14. Even though the

microcontroller 1500 may be supplied with power to operate other functionalities of the handle assembly 14 in such circumstances, the handle assembly 14 may be in a powered-down state. In a way, the electrical connector 1400 may be in a powered-down state as voltage potentials applied to the electrical contacts 1401b-1401e may not affect the operation of the handle assembly 14. The reader will appreciate that, even though contacts 1401b-1401e may be in a powered-down state, the electrical contacts 1401a and 1401f, which are not in electrical communication with the

microcontroller 1500, may or may not be in a powered-down state. For instance, sixth contact 140 If may remain in electrical communication with a ground regardless of whether the handle assembly 14 is in a powered-up or a powered-down state.

[0095] Furthermore, the transistor 1408, and/or any other suitable arrangement of transistors, such as transistor 1410, for example, and/or switches may be configured to control the supply of power from a power source 1404, such as a battery 90 within the handle assembly 14, for example, to the first electrical contact 1401a regardless of whether the handle assembly 14 is in a powered-up or a powered-down state. In various circumstances, the shaft assembly 200, for example, can be configured to change the state of the transistor 1408 when the shaft assembly 200 is engaged with the handle assembly 14. In certain circumstances, further to the below, a magnetic field sensor 1402 can be configured to switch the state of transistor 1410 which, as a result, can switch the state of transistor 1408 and ultimately supply power from power source 1404 to first contact 1401a. In this way, both the power circuits and the signal circuits to the connector 1400 can be powered down when a shaft assembly is not installed to the handle assembly 14 and powered up when a shaft assembly is installed to the handle assembly 14.

[0096] In various circumstances, referring again to FIG. 19, the handle assembly 14 can include the magnetic field sensor 1402, for example, which can be configured to detect a detectable element, such as a magnetic element 1407 (FIG. 3), for example, on a shaft assembly, such as shaft assembly 200, for example, when the shaft assembly is coupled to the handle assembly 14. The magnetic field sensor 1402 can be powered by a power source 1406, such as a battery, for example, which can, in effect, amplify the detection signal of the magnetic field sensor 1402 and communicate with an input channel of the microcontroller 1500 via the circuit illustrated in FIG. 19. Once the microcontroller 1500 has a received an input indicating that a shaft assembly has been at least partially coupled to the handle assembly 14, and that, as a result, the electrical contacts 140 la- 140 If are no longer exposed, the microcontroller 1500 can enter into its normal, or powered-up, operating state. In such an operating state, the microcontroller 1500 will evaluate the signals transmitted to one or more of the contacts 1401b-1401e from the shaft assembly and/or transmit signals to the shaft assembly through one or more of the contacts 1401b-1401e in normal use thereof. In various circumstances, the shaft assembly 200 may have to be fully seated before the magnetic field sensor 1402 can detect the magnetic element 1407. While a magnetic field sensor 1402 can be utilized to detect the presence of the shaft assembly 200, any suitable system of sensors and/or switches can be utilized to detect whether a shaft assembly has been assembled to the handle assembly 14, for example. In this way, further to the above, both the power circuits and the signal circuits to the connector 1400 can be powered down when a shaft assembly is not installed to the handle assembly 14 and powered up when a shaft assembly is installed to the handle assembly 14.

[0097] In various examples, as may be used throughout the present disclosure, any suitable magnetic field sensor may be employed to detect whether a shaft assembly has been assembled to the handle assembly 14, for example. For example, the technologies used for magnetic field sensing include Hall effect sensor, search coil, fluxgate, optically pumped, nuclear precession, SQUID, Hall-effect, anisotropic magnetoresi stance, giant magnetoresi stance, magnetic tunnel junctions, giant magnetoimpedance, magnetostrictive/piezoelectric composites, magnetodiode, magnetotransistor, fiber optic, magnetooptic, and microelectromechanical systems-based magnetic sensors, among others. [0098] Referring to FIG. 19, the microcontroller 1500 may generally comprise a microprocessor ("processor") and one or more memory units operationally coupled to the processor. By executing instruction code stored in the memory, the processor may control various components of the surgical instrument, such as the motor, various drive systems, and/or a user display, for example. The microcontroller 1500 may be implemented using integrated and/or discrete hardware elements, software elements, and/or a combination of both. Examples of integrated hardware elements may include processors, microprocessors, microcontrollers, integrated circuits, application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate arrays (FPGA), logic gates, registers, semiconductor devices, chips, microchips, chip sets, microcontrollers, system-on-chip (SoC), and/or system-in-package (SIP). Examples of discrete hardware elements may include circuits and/or circuit elements such as logic gates, field effect transistors, bipolar transistors, resistors, capacitors, inductors, and/or relays. In certain instances, the microcontroller 1500 may include a hybrid circuit comprising discrete and integrated circuit elements or components on one or more substrates, for example.

[0099] Referring to FIG. 19, the microcontroller 1500 may be an LM 4F230H5QR, available from Texas Instruments, for example. In certain instances, the Texas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Core comprising on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle serial random access memory (SRAM), internal read-only memory (ROM) loaded with StellarisWare® software, 2KB electrically erasable programmable read-only memory (EEPROM), one or more pulse width modulation (PWM) modules, one or more quadrature encoder inputs (QEI) analog, one or more 12-bit Analog-to-Digital Converters (ADC) with 12 analog input channels, among other features that are readily available. Other

microcontrollers may be readily substituted for use with the present disclosure. Accordingly, the present disclosure should not be limited in this context.

[0100] As discussed above, the handle assembly 14 and/or the shaft assembly 200 can include systems and configurations configured to prevent, or at least reduce the possibility of, the contacts of the handle electrical connector 1400 and/or the contacts of the shaft electrical connector 1410 from becoming shorted out when the shaft assembly 200 is not assembled, or completely assembled, to the handle assembly 14. Referring to FIG. 3, the handle electrical connector 1400 can be at least partially recessed within a cavity 1409 defined in the handle frame 20. The six contacts 1401a-1401f of the electrical connector 1400 can be completely recessed within the cavity 1409. Such arrangements can reduce the possibility of an object accidentally contacting one or more of the contacts 140 la- 140 If Similarly, the shaft electrical connector 1410 can be positioned within a recess defined in the shaft chassis 240 which can reduce the possibility of an object accidentally contacting one or more of the contacts 141 la-141 If of the shaft electrical connector 1410. With regard to the particular example depicted in FIG. 3, the shaft contacts 141 la-141 If can comprise male contacts. In at least one example, each shaft contact 141 la-141 If can comprise a flexible projection extending therefrom which can be configured to engage a corresponding handle contact 1401a-1401f, for example. The handle contacts 1401a-1401f can comprise female contacts. In at least one example, each handle contact 1401a-1401f can comprise a flat surface, for example, against which the male shaft contacts 140 la- 140 If can wipe, or slide, against and maintain an electrically conductive interface therebetween. In various instances, the direction in which the shaft assembly 200 is assembled to the handle assembly 14 can be parallel to, or at least substantially parallel to, the handle contacts 140 la- 140 If such that the shaft contacts 141 la-141 If slide against the handle contacts 1401a-1401f when the shaft assembly 200 is assembled to the handle assembly 14. In various alternative examples, the handle contacts 1401a-1401f can comprise male contacts and the shaft contacts 141 la-141 If can comprise female contacts. In certain alternative examples, the handle contacts 140 la- 140 If and the shaft contacts 141 la-141 If can comprise any suitable arrangement of contacts.

[0101] In various instances, the handle assembly 14 can comprise a connector guard configured to at least partially cover the handle electrical connector 1400 and/or a connector guard configured to at least partially cover the shaft electrical connector 1410. A connector guard can prevent, or at least reduce the possibility of, an object accidentally touching the contacts of an electrical connector when the shaft assembly is not assembled to, or only partially assembled to, the handle. A connector guard can be movable. For instance, the connector guard can be moved between a guarded position in which it at least partially guards a connector and an unguarded position in which it does not guard, or at least guards less of, the connector. In at least one example, a connector guard can be displaced as the shaft assembly is being assembled to the handle. For instance, if the handle comprises a handle connector guard, the shaft assembly can contact and displace the handle connector guard as the shaft assembly is being assembled to the handle.

Similarly, if the shaft assembly comprises a shaft connector guard, the handle can contact and displace the shaft connector guard as the shaft assembly is being assembled to the handle. In various instances, a connector guard can comprise a door, for example. In at least one instance, the door can comprise a beveled surface which, when contacted by the handle or shaft, can facilitate the displacement of the door in a certain direction. In various instances, the connector guard can be translated and/or rotated, for example. In certain instances, a connector guard can comprise at least one film which covers the contacts of an electrical connector. When the shaft assembly is assembled to the handle, the film can become ruptured. In at least one instance, the male contacts of a connector can penetrate the film before engaging the corresponding contacts positioned underneath the film.

[0102] As described above, the surgical instrument can include a system which can selectively power-up, or activate, the contacts of an electrical connector, such as the electrical connector 1400, for example. In various instances, the contacts can be transitioned between an unactivated condition and an activated condition. In certain instances, the contacts can be transitioned between a monitored condition, a deactivated condition, and an activated condition. For instance, the microcontroller 1500, for example, can monitor the contacts 1401a-1401f when a shaft assembly has not been assembled to the handle assembly 14 to determine whether one or more of the contacts 1401a-1401f may have been shorted. The microcontroller 1500 can be configured to apply a low voltage potential to each of the contacts 1401a-1401f and assess whether only a minimal resistance is present at each of the contacts. Such an operating state can comprise the monitored condition. In the event that the resistance detected at a contact is high, or above a threshold resistance, the microcontroller 1500 can deactivate that contact, more than one contact, or, alternatively, all of the contacts. Such an operating state can comprise the deactivated condition. If a shaft assembly is assembled to the handle assembly 14 and it is detected by the microcontroller 1500, as discussed above, the microcontroller 1500 can increase the voltage potential to the contacts 1401a-1401f. Such an operating state can comprise the activated condition.

[0103] The various shaft assemblies disclosed herein may employ sensors and various other components that require electrical communication with the controller in the housing. These shaft assemblies generally are configured to be able to rotate relative to the housing necessitating a connection that facilitates such electrical communication between two or more components that may rotate relative to each other. When employing end effectors of the types disclosed herein, the connector arrangements must be relatively robust in nature while also being somewhat compact to fit into the shaft assembly connector portion.

[0104] Referring to FIG. 20, a non-limiting form of the end effector 300 is illustrated. As described above, the end effector 300 may include the anvil 306 and the staple cartridge 304. In this non- limiting example, the anvil 306 is coupled to an elongate channel 198. For example, apertures 199 can be defined in the elongate channel 198 which can receive pins 152 extending from the anvil 306 and allow the anvil 306 to pivot from an open position to a closed position relative to the elongate channel 198 and staple cartridge 304. In addition, FIG. 20 shows a firing bar 172, configured to longitudinally translate into the end effector 300. The firing bar 172 may be constructed from one solid section, or in various examples, may include a laminate material comprising, for example, a stack of steel plates. A distally projecting end of the firing bar 172 can be attached to an E-beam 178 that can, among other things, assist in spacing the anvil 306 from a staple cartridge 304 positioned in the elongate channel 198 when the anvil 306 is in a closed position. The E-beam 178 can also include a sharpened cutting edge 182 which can be used to sever tissue as the E-beam 178 is advanced distally by the firing bar 172. In operation, the E-beam 178 can also actuate, or fire, the staple cartridge 304. The staple cartridge 304 can include a molded cartridge body 194 that holds a plurality of staples 191 resting upon staple drivers 192 within respective upwardly open staple cavities 195. A wedge sled 190 is driven distally by the E-beam 178, sliding upon a cartridge tray 196 that holds together the various components of the replaceable staple cartridge 304. The wedge sled 190 upwardly cams the staple drivers 192 to force out the staples 191 into deforming contact with the anvil 306 while a cutting surface 182 of the E-beam 178 severs clamped tissue.

[0105] Further to the above, the E-beam 178 can include upper pins 180 which engage the anvil 306 during firing. The E-beam 178 can further include middle pins 184 and a bottom foot 186 which can engage various portions of the cartridge body 194, cartridge tray 196 and elongate channel 198. When a staple cartridge 304 is positioned within the elongate channel 198, a slot 193 defined in the cartridge body 194 can be aligned with a slot 197 defined in the cartridge tray 196 and a slot 189 defined in the elongate channel 198. In use, the E-beam 178 can slide through the aligned slots 193, 197, and 189 wherein, as indicated in FIG. 20, the bottom foot 186 of the E-beam 178 can engage a groove running along the bottom surface of channel 198 along the length of slot 189, the middle pins 184 can engage the top surfaces of cartridge tray 196 along the length of longitudinal slot 197, and the upper pins 180 can engage the anvil 306. In such circumstances, the E-beam 178 can space, or limit the relative movement between, the anvil 306 and the staple cartridge 304 as the firing bar 172 is moved distally to fire the staples from the staple cartridge 304 and/or incise the tissue captured between the anvil 306 and the staple cartridge 304. Thereafter, the firing bar 172 and the E-beam 178 can be retracted proximally allowing the anvil 306 to be opened to release the two stapled and severed tissue portions (not shown). [0106] Having described a surgical instrument 10 (FIGS. 1-4) in general terms, the description now turns to a detailed description of various electrical/electronic components of the surgical instrument 10. Turning now to FIGS. 21 A-21B, where one example of a segmented circuit 2000 comprising a plurality of circuit segments 2002a-2002g is illustrated. The segmented circuit 2000 comprising the plurality of circuit segments 2002a-2002g is configured to control a powered surgical instrument, such as, for example, the surgical instrument 10 illustrated in FIGS. 1-18 A, without limitation. The plurality of circuit segments 2002a-2002g is configured to control one or more operations of the powered surgical instrument 10. A safety processor segment 2002a (Segment 1) comprises a safety processor 2004. A primary processor segment 2002b (Segment 2) comprises a primary or main processor 2006. The safety processor 2004 and/or the primary processor 2006 are configured to interact with one or more additional circuit segments 2002c-2002g to control operation of the powered surgical instrument 10. The primary processor 2006 comprises a plurality of inputs coupled to, for example, one or more circuit segments 2002c-2002g, a battery 2008, and/or a plurality of switches 2056-2070. The segmented circuit 2000 may be implemented by any suitable circuit, such as, for example, a printed circuit board assembly (PCB A) within the powered surgical instrument 10. It should be understood that the term processor as used herein includes any microprocessor, microcontroller, or other basic computing device that incorporates the functions of a computer's central processing unit (CPU) on an integrated circuit or at most a few integrated circuits. The processor is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and provides results as output. It is an example of sequential digital logic, as it has internal memory. Processors operate on numbers and symbols represented in the binary numeral system.

[0107] In one aspect, the main processor 2006 may be any single core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. In one example, the safety processor 2004 may be a safety microcontroller platform comprising two microcontroller- based families such as TMS570 and RM4x known under the trade name Hercules ARM Cortex R4, also by Texas Instruments. Nevertheless, other suitable substitutes for microcontrollers and safety processor may be employed, without limitation. In one example, the safety processor 2004 may be configured specifically for IEC 61508 and ISO 26262 safety critical applications, among others, to provide advanced integrated safety features while delivering scalable performance, connectivity, and memory options. [0108] In certain instances, the main processor 2006 may be an LM 4F230H5QR, available from Texas Instruments, for example. In at least one example, the Texas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Core comprising on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle SRAM, internal ROM loaded with StellarisWare® software, 2KB EEPROM, one or more PWM modules, one or more QEI analog, one or more 12-bit ADC with 12 analog input channels, among other features that are readily available for the product datasheet. Other processors may be readily substituted and, accordingly, the present disclosure should not be limited in this context.

[0109] In one aspect, the segmented circuit 2000 comprises an acceleration segment 2002c (Segment 3). The acceleration segment 2002c comprises an acceleration sensor 2022. The acceleration sensor 2022 may comprise, for example, an accelerometer. The acceleration sensor 2022 is configured to detect movement or acceleration of the powered surgical instrument 10. In some examples, input from the acceleration sensor 2022 is used, for example, to transition to and from a sleep mode, identify an orientation of the powered surgical instrument, and/or identify when the surgical instrument has been dropped. In some examples, the acceleration segment 2002c is coupled to the safety processor 2004 and/or the primary processor 2006.

[0110] In some aspects, the segmented circuit 2000 comprises a display segment 2002d (Segment 4). According to various embodiments, the display segment 2002d comprises a display connector (not shown) which is coupled to the primary processor 2006, one or more display driver integrated circuits (not shown) which are coupled to the display connector, and a display 2028 which is coupled to the one or more display driver integrated circuits. The display connector and the one or more display driver integrated circuits are shown, for example, in FIG. 4B of U.S. Patent

Application Serial No. 14/226,076, the content of which is hereby incorporated by reference in its entirety. The display driver integrated circuits may be integrated with the display 2028 and/or may be located separately from the display 2028. The display 2028 may comprise any suitable display, such as, for example, an organic light-emitting diode (OLED) display, a liquid-crystal display (LCD), and/or any other suitable display. In some examples, the display segment 2002d is coupled to the safety processor 2004.

[0111] In some aspects, the segmented circuit 2000 comprises a shaft segment 2002e (Segment 5). The shaft segment 2002e comprises one or more controls for a shaft assembly (e.g., shaft assembly 200) coupled to the surgical instrument 10 and/or one or more controls for an end effector (e.g., end effector 300) coupled to the shaft 200. According to various embodiments, the shaft segment 2002e comprises a shaft connector 2030 and a shaft printed circuit board assembly (PCB A) 2031. The shaft connector 2030 is configured to couple the shaft PCBA 2031 to the primary processor 2006. According to various embodiments, the shaft PCBA 2031 comprises a first articulation switch (not shown), a second articulation switch (not shown), and a shaft PCBA EEPROM (not shown). In some examples, the shaft PCBA EEPROM comprises one or more parameters, routines, and/or programs specific to the shaft assembly 200 and/or the shaft PCBA 2031. The shaft PCBA 2031 may be coupled to the shaft assembly 200 and/or integral with the surgical instrument 10. In some examples, the shaft segment 2002e comprises a second shaft EEPROM (not shown). The second shaft EEPROM comprises a plurality of algorithms, routines, parameters, and/or other data corresponding to one or more shaft assemblies 200 and/or end effectors 300 which may be interfaced with the powered surgical instrument 10. The first articulation switch, the second articulation switch, and the shaft PCBA EEPROMs are shown, for example, in FIG. 4 A of U.S. Patent Application Serial No. 14/226,076, the content of which is hereby incorporated by reference in its entirety. According to other embodiments, as shown in FIG. 21 A, the shaft segment 2002 e comprises the shaft PCBA 2031, a Hall effect sensor 2070 and the shaft connector 2025. The shaft PCBA 2031 comprises a low-power microprocessor 2090 with ferroelectric random access memory (FRAM) technology, a mechanical articulation switch 2092, a shaft release Hall effect switch 2094 and flash memory 2034. The Hall effect sensor 2070 is utilized to indicate engagement of the shaft assembly 200 and thus may be considered a shaft engaged switch.

[0112] In some aspects, the segmented circuit 2000 comprises a position encoder segment 2002f (Segment 6). The position encoder segment 2002f comprises one or more magnetic rotary position encoders 2040a-2040b. The one or more magnetic rotary position encoders 2040a-2040b are configured to identify the rotational position of a motor 2048, a shaft assembly 200, and/or an end effector 300 of the surgical instrument 10. In some examples, the magnetic rotary position encoders 2040a-2040b may be coupled to the safety processor 2004 and/or the primary processor 2006.

[0113] In some aspects, the segmented circuit 2000 comprises a motor segment 2002g (Segment 7). The motor segment 2002g comprises a motor 2048, such as, for example, a brushed DC motor, configured to control one or more movements of the powered surgical instrument 10. The motor 2048 is coupled to the primary processor 2006 through a motor controller 2043, a plurality of H- bridge drivers 2042 and a plurality of H-bridge field-effect transistors (not shown). According to various embodiments, the H-bridge field-effect transistors (FETs) are coupled to the safety processor 2004. The H-bridge FETs are shown, for example, in FIG. 4B of U.S. Patent Application Serial No. 14/226,076, the content of which is hereby incorporated by reference in its entirety. The motor controller 2043 controls a first motor flag 2074a and a second motor flag 2074b to indicate the status and position of the motor 2048 to the primary processor 2006. The primary processor 2006 provides a pulse-width modulation (PWM) high signal 2076a, a PWM low signal 2076b, a direction signal 2078, a synchronize signal 2080, and a motor reset signal 2082 to the motor controller 2043 through a buffer 2084. A motor current sensor 2046 is coupled in series with the motor 2048 to measure the current draw of the motor 2048. The motor current sensor 2046 is in signal communication with the primary processor 2006 and/or the safety processor 2004. In some examples, the motor 2048 is coupled to a motor electromagnetic interference (EMI) filter (not shown). The EMI filter is shown, for example, in FIG. 3B of U.S. Patent Application Serial No. 14/226,076, the content of which is hereby incorporated by reference in its entirety.

[0114] In some aspects, the segmented circuit 2000 comprises a power segment 2002h (Segment 8) configured to provide a segment voltage to each of the circuit segments 1102a-l 102g. A battery 2008 is coupled to the safety processor 2004, the primary processor 2006, and one or more of the additional circuit segments 2002c-2002g. The battery 2008 is coupled to the segmented circuit 2000 by a battery connector 2010 and a current sensor 2012. The current sensor 2012 is configured to measure the total current draw of the segmented circuit 2000. In some examples, one or more voltage converters 2014a, 2014b, 2016 are configured to provide predetermined voltage values to one or more circuit segments 2002a-2002g. For example, in some examples, the segmented circuit 2000 may comprise 3.3V voltage converters 2014a-2014b and/or 5V voltage converters 2016. A boost converter 2018 is configured to provide a boost voltage up to a predetermined amount, such as, for example, up to 13 V. The boost converter 2018 is configured to provide additional voltage and/or current during power intensive operations and prevent brownout or low-power conditions. A transistor switch (e.g., N-Channel MOSFET) 2015 is coupled to the power converters 2014B, 2016.

[0115] In some aspects, the safety segment 2002a comprises a motor power interrupt 2020. The motor power interrupt 2020 is coupled between the power segment 2002h and the motor segment 2002g. A transistor switch (e.g., N-Channel MOSFET) 2057 is coupled to the motor power interrupt 2020. The safety segment 2002a is configured to interrupt power to the motor segment 2002g when an error or fault condition is detected by the safety processor 2004 and/or the primary processor 2006 as discussed in more detail herein. Although the circuit segments 2002a-2002g are illustrated with all components of the circuit segments 2002a-2002h located in physical proximity, one skilled in the art will recognize that a circuit segment 2002a-2002h may comprise components physically and/or electrically separate from other components of the same circuit segment 2002a- 2002g. In some examples, one or more components may be shared between two or more circuit segments 2002a-2002g.

[0116] In some aspects, a plurality of switches 2056-2070 are coupled to the safety processor 2004 and/or the primary processor 2006. The plurality of switches 2056-2070 may be configured to control one or more operations of the surgical instrument 10, control one or more operations of the segmented circuit 2000, and/or indicate a status of the surgical instrument 10. For example, a bailout door switch 2056 is configured to indicate the status of a bail-out door. A plurality of articulation switches, such as, for example, a left side articulation left switch 2058a, a left side articulation right switch 2060a, a left side articulation center switch 2062a, a right side articulation left switch 2058b, a right side articulation right switch 2060b, and a right side articulation center switch 2062b are configured to control articulation of a shaft assembly 200 and/or an end effector 300. A left side reverse switch 2064a and a right side reverse switch 2064b are coupled to the primary processor 2006. In some examples, the left side switches comprising the left side articulation left switch 2058a, the left side articulation right switch 2060a, the left side articulation center switch 2062a, and the left side reverse switch 2064a are coupled to the primary processor 2006 by a left flex connector (not shown). The right side switches comprising the right side articulation left switch 2058b, the right side articulation right switch 2060b, the right side articulation center switch 2062b, and the right side reverse switch 2064b are coupled to the primary processor 2006 by a right flex connector (not shown). The left flex connector and the right flex connector are shown, for example, in FIG. 3A of U.S. Patent Application Serial No. 14/226,076, the content of which is hereby incorporated by reference in its entirety. In some examples, a firing switch 2066, a clamp release switch 2068, and the Hall effect sensor/shaft engaged switch 2070 are coupled to the primary processor 2006.

[0117] In some aspects, the plurality of switches 2056-2070 may comprise, for example, a plurality of handle controls mounted to a handle of the surgical instrument 10, a plurality of indicator switches, and/or any combination thereof. In various examples, the plurality of switches 2056-2070 allow a surgeon to manipulate the surgical instrument, provide feedback to the segmented circuit 2000 regarding the position and/or operation of the surgical instrument, and/or indicate unsafe operation of the surgical instrument 10. In some examples, additional or fewer switches may be coupled to the segmented circuit 2000, one or more of the switches 2056-2070 may be combined into a single switch, and/or expanded to multiple switches. For example, in one example, one or more of the left side and/or right side articulation switches 2058a-2064b may be combined into a single multi-position switch.

[0118] In one aspect, the safety processor 2004 is configured to implement a watchdog function, among other safety operations. The safety processor 2004 and the primary processor 2006 of the segmented circuit 2000 are in signal communication. The primary processor 2006 is also coupled to a flash memory 2086. A microprocessor alive heartbeat signal is provided at output 2096. The acceleration segment 2002c comprises an accelerometer 2022 configured to monitor movement of the surgical instrument 10. In various examples, the accelerometer 2022 may be a single, double, or triple axis accelerometer. The accelerometer 2022 may be employed to measure proper acceleration that is not necessarily the coordinate acceleration (rate of change of velocity). Instead, the accelerometer sees the acceleration associated with the phenomenon of weight experienced by a test mass at rest in the frame of reference of the accelerometer 2022. For example, the accelerometer 2022 at rest on the surface of the earth will measure an acceleration g=9.8 m/s ² (gravity) straight upwards, due to its weight. Another type of acceleration that accelerometer 2022 can measure is g- force acceleration. In various other examples, the accelerometer 2022 may comprise a single, double, or triple axis accelerometer. Further, the acceleration segment 2002c may comprise one or more inertial sensors to detect and measure acceleration, tilt, shock, vibration, rotation, and multiple degrees-of-freedom (DoF). A suitable inertial sensor may comprise an accelerometer (single, double, or triple axis), a magnetometer to measure a magnetic field in space such as the earth's magnetic field, and/or a gyroscope to measure angular velocity.

[0119] In one aspect, the safety processor 2004 is configured to implement a watchdog function with respect to one or more circuit segments 2002c-2002h, such as, for example, the motor segment 2002g. In this regards, the safety processor 2004 employs the watchdog function to detect and recover from malfunctions of the primary processor 2006. During normal operation, the safety processor 2004 monitors for hardware faults or program errors of the primary processor 2006 and to initiate corrective action or actions. The corrective actions may include placing the primary processor 2006 in a safe state and restoring normal system operation. In one example, the safety processor 2004 is coupled to at least a first sensor. The first sensor measures a first property of the surgical instrument 10 (FIGS. 1-4). In some examples, the safety processor 2004 is configured to compare the measured property of the surgical instrument 10 to a predetermined value. For example, in one example, a motor sensor 2040a (e.g., a magnetic rotary position encoder) is coupled to the safety processor 2004. The motor sensor 2040a provides motor speed and position information to the safety processor 2004. The safety processor 2004 monitors the motor sensor 2040a and compares the value to a maximum speed and/or position value and prevents operation of the motor 2048 above the predetermined values. In some examples, the predetermined values are calculated based on real-time speed and/or position of the motor 2048, calculated from values supplied by a second motor sensor 2040b (e.g., a magnetic rotary position encoder) in

communication with the primary processor 2006, and/or provided to the safety processor 2004 from, for example, a memory module coupled to the safety processor 2004.

[0120] In some aspects, a second sensor is coupled to the primary processor 2006. The second sensor is configured to measure the first physical property. The safety processor 2004 and the primary processor 2006 are configured to provide a signal indicative of the value of the first sensor and the second sensor respectively. When either the safety processor 2004 or the primary processor 2006 indicates a value outside of an acceptable range, the segmented circuit 2000 prevents operation of at least one of the circuit segments 2002c-2002h, such as, for example, the motor segment 2002g. For example, in the example illustrated in FIGS. 21 A-21B, the safety processor 2004 is coupled to a first motor position sensor 2040a and the primary processor 2006 is coupled to a second motor position sensor 2040b. The motor position sensors 2040a, 2040b may comprise any suitable motor position sensor, such as, for example, a magnetic angle rotary input comprising a sine and cosine output. The motor position sensors 2040a, 2040b provide respective signals to the safety processor 2004 and the primary processor 2006 indicative of the position of the motor 2048.

[0121] The safety processor 2004 and the primary processor 2006 generate an activation signal when the values of the first motor sensor 2040a and the second motor sensor 2040b are within a predetermined range. When either the primary processor 2006 or the safety processor 2004 detect a value outside of the predetermined range, the activation signal is terminated and operation of at least one circuit segment 2002c-2002h, such as, for example, the motor segment 2002g, is interrupted and/or prevented. For example, in some examples, the activation signal from the primary processor 2006 and the activation signal from the safety processor 2004 are coupled to an AND gate 2059. The AND gate 2059 is coupled to a motor power switch 2020. The AND gate 2059 maintains the motor power switch 2020 in a closed, or on, position when the activation signal from both the safety processor 2004 and the primary processor 2006 are high, indicating a value of the motor sensors 2040a, 2040b within the predetermined range. When either of the motor sensors 2040a, 2040b detect a value outside of the predetermined range, the activation signal from that motor sensor 2040a, 2040b is set low, and the output of the AND gate 2059 is set low, opening the motor power switch 2020. In some examples, the value of the first sensor 2040a and the second sensor 2040b is compared, for example, by the safety processor 2004 and/or the primary processor 2006. When the values of the first sensor and the second sensor are different, the safety processor 2004 and/or the primary processor 2006 may prevent operation of the motor segment 2002g.

[0122] In some aspects, the safety processor 2004 receives a signal indicative of the value of the second sensor 2040b and compares the second sensor value to the first sensor value. For example, in one aspect, the safety processor 2004 is coupled directly to a first motor sensor 2040a. A second motor sensor 2040b is coupled to a primary processor 2006, which provides the second motor sensor 2040b value to the safety processor 2004, and/or coupled directly to the safety processor 2004. The safety processor 2004 compares the value of the first motor sensor 2040 to the value of the second motor sensor 2040b. When the safety processor 2004 detects a mismatch between the first motor sensor 2040a and the second motor sensor 2040b, the safety processor 2004 may interrupt operation of the motor segment 2002g, for example, by cutting power to the motor segment 2002g.

[0123] In some aspects, the safety processor 2004 and/or the primary processor 2006 is coupled to a first sensor 2040a configured to measure a first property of a surgical instrument and a second sensor 2040b configured to measure a second property of the surgical instrument. The first property and the second property comprise a predetermined relationship when the surgical instrument is operating normally. The safety processor 2004 monitors the first property and the second property. When a value of the first property and/or the second property inconsistent with the predetermined relationship is detected, a fault occurs. When a fault occurs, the safety processor 2004 takes at least one action, such as, for example, preventing operation of at least one of the circuit segments, executing a predetermined operation, and/or resetting the primary processor 2006. For example, the safety processor 2004 may open the motor power switch 2020 to cut power to the motor circuit segment 2002g when a fault is detected.

[0124] In one aspect, the safety processor 2004 is configured to execute an independent control algorithm. In operation, the safety processor 2004 monitors the segmented circuit 2000 and is configured to control and/or override signals from other circuit components, such as, for example, the primary processor 2006, independently. The safety processor 2004 may execute a

preprogrammed algorithm and/or may be updated or programmed on the fly during operation based on one or more actions and/or positions of the surgical instrument 10. For example, in one example, the safety processor 2004 is reprogrammed with new parameters and/or safety algorithms each time a new shaft and/or end effector is coupled to the surgical instrument 10. In some examples, one or more safety values stored by the safety processor 2004 are duplicated by the primary processor 2006. Two-way error detection is performed to ensure values and/or parameters stored by either of the processors 2004, 2006 are correct.

[0125] In some aspects, the safety processor 2004 and the primary processor 2006 implement a redundant safety check. The safety processor 2004 and the primary processor 2006 provide periodic signals indicating normal operation. For example, during operation, the safety processor 2004 may indicate to the primary processor 2006 that the safety processor 2004 is executing code and operating normally. The primary processor 2006 may, likewise, indicate to the safety processor 2004 that the primary processor 2006 is executing code and operating normally. In some examples, communication between the safety processor 2004 and the primary processor 2006 occurs at a predetermined interval. The predetermined interval may be constant or may be variable based on the circuit state and/or operation of the surgical instrument 10.

[0126] FIG. 22 illustrates one example of a power assembly 2100 comprising a usage cycle circuit 2102 configured to monitor a usage cycle count of the power assembly 2100. The power assembly 2100 may be coupled to a surgical instrument 2110. The usage cycle circuit 2102 comprises a processor 2104 and a use indicator 2106. The use indicator 2106 is configured to provide a signal to the processor 2104 to indicate a use of the battery back 2100 and/or a surgical instrument 2110 coupled to the power assembly 2100. A "use" may comprise any suitable action, condition, and/or parameter such as, for example, changing a modular component of a surgical instrument 2110, deploying or firing a disposable component coupled to the surgical instrument 2110, delivering electrosurgical energy from the surgical instrument 2110, reconditioning the surgical instrument 2110 and/or the power assembly 2100, exchanging the power assembly 2100, recharging the power assembly 2100, and/or exceeding a safety limitation of the surgical instrument 2110 and/or the battery back 2100.

[0127] In some instances, a usage cycle, or use, is defined by one or more power assembly 2100 parameters. For example, in one instance, a usage cycle comprises using more than 5% of the total energy available from the power assembly 2100 when the power assembly 2100 is at a full charge level. In another instance, a usage cycle comprises a continuous energy drain from the power assembly 2100 exceeding a predetermined time limit. For example, a usage cycle may correspond to five minutes of continuous and/or total energy draw from the power assembly 2100. In some instances, the power assembly 2100 comprises a usage cycle circuit 2102 having a continuous power draw to maintain one or more components of the usage cycle circuit 2102, such as, for example, the use indicator 2106 and/or a counter 2108, in an active state.

[0128] The processor 2104 maintains a usage cycle count. The usage cycle count indicates the number of uses detected by the use indicator 2106 for the power assembly 2100 and/or the surgical instrument 2110. The processor 2104 may increment and/or decrement the usage cycle count based on input from the use indicator 2106. The usage cycle count is used to control one or more operations of the power assembly 2100 and/or the surgical instrument 2110. For example, in some instances, a power assembly 2100 is disabled when the usage cycle count exceeds a predetermined usage limit. Although the instances discussed herein are discussed with respect to incrementing the usage cycle count above a predetermined usage limit, those skilled in the art will recognize that the usage cycle count may start at a predetermined amount and may be decremented by the processor 2104. In this instance, the processor 2104 initiates and/or prevents one or more operations of the power assembly 2100 when the usage cycle count falls below a predetermined usage limit.

[0129] The usage cycle count is maintained by a counter 2108. The counter 2108 comprises any suitable circuit, such as, for example, a memory module, an analog counter, and/or any circuit configured to maintain a usage cycle count. In some instances, the counter 2108 is formed integrally with the processor 2104. In other instances, the counter 2108 comprises a separate component, such as, for example, a solid state memory module. In some instances, the usage cycle count is provided to a remote system, such as, for example, a central database. The usage cycle count is transmitted by a communications module 2112 to the remote system. The communications module 2112 is configured to use any suitable communications medium, such as, for example, wired and/or wireless communication. In some instances, the communications module 2112 is configured to receive one or more instructions from the remote system, such as, for example, a control signal when the usage cycle count exceeds the predetermined usage limit.

[0130] In some instances, the use indicator 2106 is configured to monitor the number of modular components used with a surgical instrument 2110 coupled to the power assembly 2100. A modular component may comprise, for example, a modular shaft, a modular end effector, and/or any other modular component. In some instances, the use indicator 2106 monitors the use of one or more disposable components, such as, for example, insertion and/or deployment of a staple cartridge within an end effector coupled to the surgical instrument 2110. The use indicator 2106 comprises one or more sensors for detecting the exchange of one or more modular and/or disposable components of the surgical instrument 2110.

[0131] In some instances, the use indicator 2106 is configured to monitor single patient surgical procedures performed while the power assembly 2100 is installed. For example, the use indicator 2106 may be configured to monitor firings of the surgical instrument 2110 while the power assembly 2100 is coupled to the surgical instrument 2110. A firing may correspond to deployment of a staple cartridge, application of electrosurgical energy, and/or any other suitable surgical event. The use indicator 2106 may comprise one or more circuits for measuring the number of firings while the power assembly 2100 is installed. The use indicator 2106 provides a signal to the processor 2104 when a single patient procedure is performed and the processor 2104 increments the usage cycle count.

[0132] In some instances, the use indicator 2106 comprises a circuit configured to monitor one or more parameters of the power source 2114, such as, for example, a current draw from the power source 2114. The one or more parameters of the power source 2114 correspond to one or more operations performable by the surgical instrument 2110, such as, for example, a cutting and sealing operation. The use indicator 2106 provides the one or more parameters to the processor 2104, which increments the usage cycle count when the one or more parameters indicate that a procedure has been performed.

[0133] In some instances, the use indicator 2106 comprises a timing circuit configured to increment a usage cycle count after a predetermined time period. The predetermined time period corresponds to a single patient procedure time, which is the time required for an operator to perform a procedure, such as, for example, a cutting and sealing procedure. When the power assembly 2100 is coupled to the surgical instrument 2110, the processor 2104 polls the use indicator 2106 to determine when the single patient procedure time has expired. When the predetermined time period has elapsed, the processor 2104 increments the usage cycle count. After incrementing the usage cycle count, the processor 2104 resets the timing circuit of the use indicator 2106.

[0134] In some instances, the use indicator 2106 comprises a time constant that approximates the single patient procedure time. In one example, the usage cycle circuit 2102 comprises a resistor- capacitor (RC) timing circuit 2506. The RC timing circuit comprises a time constant defined by a resistor-capacitor pair. The time constant is defined by the values of the resistor and the capacitor. In one example, the usage cycle circuit 2552 comprises a rechargeable battery and a clock. When the power assembly 2100 is installed in a surgical instrument, the rechargeable battery is charged by the power source. The rechargeable battery comprises enough power to run the clock for at least the single patient procedure time. The clock may comprise a real time clock, a processor configured to implement a time function, or any other suitable timing circuit.

[0135] Referring still to FIG. 22, in some instances, the use indicator 2106 comprises a sensor configured to monitor one or more environmental conditions experienced by the power assembly 2100. For example, the use indicator 2106 may comprise an accelerometer. The accelerometer is configured to monitor acceleration of the power assembly 2100. The power assembly 2100 comprises a maximum acceleration tolerance. Acceleration above a predetermined threshold indicates, for example, that the power assembly 2100 has been dropped. When the use indicator 2106 detects acceleration above the maximum acceleration tolerance, the processor 2104 increments a usage cycle count. In some instances, the use indicator 2106 comprises a moisture sensor. The moisture sensor is configured to indicate when the power assembly 2100 has been exposed to moisture. The moisture sensor may comprise, for example, an immersion sensor configured to indicate when the power assembly 2100 has been fully immersed in a cleaning fluid, a moisture sensor configured to indicate when moisture is in contact with the power assembly 2100 during use, and/or any other suitable moisture sensor.

[0136] In some instances, the use indicator 2106 comprises a chemical exposure sensor. The chemical exposure sensor is configured to indicate when the power assembly 2100 has come into contact with harmful and/or dangerous chemicals. For example, during a sterilization procedure, an inappropriate chemical may be used that leads to degradation of the power assembly 2100. The processor 2104 increments the usage cycle count when the use indicator 2106 detects an

inappropriate chemical.

[0137] In some instances, the usage cycle circuit 2102 is configured to monitor the number of reconditioning cycles experienced by the power assembly 2100. A reconditioning cycle may comprise, for example, a cleaning cycle, a sterilization cycle, a charging cycle, routine and/or preventative maintenance, and/or any other suitable reconditioning cycle. The use indicator 2106 is configured to detect a reconditioning cycle. For example, the use indicator 2106 may comprise a moisture sensor to detect a cleaning and/or sterilization cycle. In some instances, the usage cycle circuit 2102 monitors the number of reconditioning cycles experienced by the power assembly 2100 and disables the power assembly 2100 after the number of reconditioning cycles exceeds a predetermined threshold. [0138] The usage cycle circuit 2102 may be configured to monitor the number of power assembly 2100 exchanges. The usage cycle circuit 2102 increments the usage cycle count each time the power assembly 2100 is exchanged. When the maximum number of exchanges is exceeded the usage cycle circuit 2102 locks out the power assembly 2100 and/or the surgical instrument 2110. In some instances, when the power assembly 2100 is coupled the surgical instrument 2110, the usage cycle circuit 2102 identifies the serial number of the power assembly 2100 and locks the power assembly 2100 such that the power assembly 2100 is usable only with the surgical instrument 2110. In some instances, the usage cycle circuit 2102 increments the usage cycle each time the power assembly 2100 is removed from and/or coupled to the surgical instrument 2110.

[0139] In some instances, the usage cycle count corresponds to sterilization of the power assembly 2100. The use indicator 2106 comprises a sensor configured to detect one or more parameters of a sterilization cycle, such as, for example, a temperature parameter, a chemical parameter, a moisture parameter, and/or any other suitable parameter. The processor 2104 increments the usage cycle count when a sterilization parameter is detected. The usage cycle circuit 2102 disables the power assembly 2100 after a predetermined number of sterilizations. In some instances, the usage cycle circuit 2102 is reset during a sterilization cycle, a voltage sensor to detect a recharge cycle, and/or any suitable sensor. The processor 2104 increments the usage cycle count when a reconditioning cycle is detected. The usage cycle circuit 2102 is disabled when a sterilization cycle is detected. The usage cycle circuit 2102 is reactivated and/or reset when the power assembly 2100 is coupled to the surgical instrument 2110. In some instances, the use indicator comprises a zero power indicator. The zero power indicator changes state during a sterilization cycle and is checked by the processor 2104 when the power assembly 2100 is coupled to a surgical instrument 2110. When the zero power indicator indicates that a sterilization cycle has occurred, the processor 2104 increments the usage cycle count.

[0140] A counter 2108 maintains the usage cycle count. In some instances, the counter 2108 comprises a non-volatile memory module. The processor 2104 increments the usage cycle count stored in the non-volatile memory module each time a usage cycle is detected. The memory module may be accessed by the processor 2104 and/or a control circuit, such as, for example, the control circuit 2000. When the usage cycle count exceeds a predetermined threshold, the processor 2104 disables the power assembly 2100. In some instances, the usage cycle count is maintained by a plurality of circuit components. For example, in one instance, the counter 2108 comprises a resistor (or fuse) pack. After each use of the power assembly 2100, a resistor (or fuse) is burned to an open position, changing the resistance of the resistor pack. The power assembly 2100 and/or the surgical instrument 2110 reads the remaining resistance. When the last resistor of the resistor pack is burned out, the resistor pack has a predetermined resistance, such as, for example, an infinite resistance corresponding to an open circuit, which indicates that the power assembly 2100 has reached its usage limit. In some instances, the resistance of the resistor pack is used to derive the number of uses remaining.

[0141] In some instances, the usage cycle circuit 2102 prevents further use of the power assembly 2100 and/or the surgical instrument 2110 when the usage cycle count exceeds a predetermined usage limit. In one instance, the usage cycle count associated with the power assembly 2100 is provided to an operator, for example, utilizing a screen formed integrally with the surgical instrument 2110. The surgical instrument 2110 provides an indication to the operator that the usage cycle count has exceeded a predetermined limit for the power assembly 2100, and prevents further operation of the surgical instrument 2110.

[0142] In some instances, the usage cycle circuit 2102 is configured to physically prevent operation when the predetermined usage limit is reached. For example, the power assembly 2100 may comprise a shield configured to deploy over contacts of the power assembly 2100 when the usage cycle count exceeds the predetermined usage limit. The shield prevents recharge and use of the power assembly 2100 by covering the electrical connections of the power assembly 2100.

[0143] In some instances, the usage cycle circuit 2102 is located at least partially within the surgical instrument 2110 and is configured to maintain a usage cycle count for the surgical instrument 2110. FIG. 22 illustrates one or more components of the usage cycle circuit 2102 within the surgical instrument 2110 in phantom, illustrating the alternative positioning of the usage cycle circuit 2102. When a predetermined usage limit of the surgical instrument 2110 is exceeded, the usage cycle circuit 2102 disables and/or prevents operation of the surgical instrument 21 10. The usage cycle count is incremented by the usage cycle circuit 2102 when the use indicator 2106 detects a specific event and/or requirement, such as, for example, firing of the surgical instrument 2110, a

predetermined time period corresponding to a single patient procedure time, based on one or more motor parameters of the surgical instrument 2110, in response to a system diagnostic indicating that one or more predetermined thresholds are met, and/or any other suitable requirement. As discussed above, in some instances, the use indicator 2106 comprises a timing circuit corresponding to a single patient procedure time. In other instances, the use indicator 2106 comprises one or more sensors configured to detect a specific event and/or condition of the surgical instrument 2110. [0144] In some instances, the usage cycle circuit 2102 is configured to prevent operation of the surgical instrument 2110 after the predetermined usage limit is reached. In some instances, the surgical instrument 2110 comprises a visible indicator to indicate when the predetermined usage limit has been reached and/or exceeded. For example, a flag, such as a red flag, may pop-up from the surgical instrument 2110, such as from the handle, to provide a visual indication to the operator that the surgical instrument 2110 has exceeded the predetermined usage limit. As another example, the usage cycle circuit 2102 may be coupled to a display formed integrally with the surgical instrument 2110. The usage cycle circuit 2102 displays a message indicating that the predetermined usage limit has been exceeded. The surgical instrument 2110 may provide an audible indication to the operator that the predetermined usage limit has been exceeded. For example, in one instance, the surgical instrument 2110 emits an audible tone when the predetermined usage limit is exceeded and the power assembly 2100 is removed from the surgical instrument 2110. The audible tone indicates the last use of the surgical instrument 2110 and indicates that the surgical instrument 2110 should be disposed or reconditioned.

[0145] In some instances, the usage cycle circuit 2102 is configured to transmit the usage cycle count of the surgical instrument 2110 to a remote location, such as, for example, a central database. The usage cycle circuit 2102 comprises a communications module 2112 configured to transmit the usage cycle count to the remote location. The communications module 2112 may utilize any suitable communications system, such as, for example, wired or wireless communications system. The remote location may comprise a central database configured to maintain usage information. In some instances, when the power assembly 2100 is coupled to the surgical instrument 2110, the power assembly 2100 records a serial number of the surgical instrument 2110. The serial number is transmitted to the central database, for example, when the power assembly 2100 is coupled to a charger. In some instances, the central database maintains a count corresponding to each use of the surgical instrument 2110. For example, a bar code associated with the surgical instrument 2110 may be scanned each time the surgical instrument 2110 is used. When the use count exceeds a predetermined usage limit, the central database provides a signal to the surgical instrument 2110 indicating that the surgical instrument 2110 should be discarded.

[0146] The surgical instrument 2110 may be configured to lock and/or prevent operation of the surgical instrument 2110 when the usage cycle count exceeds a predetermined usage limit. In some instances, the surgical instrument 2110 comprises a disposable instrument and is discarded after the usage cycle count exceeds the predetermined usage limit. In other instances, the surgical instrument 2110 comprises a reusable surgical instrument which may be reconditioned after the usage cycle count exceeds the predetermined usage limit. The surgical instrument 2110 initiates a reversible lockout after the predetermined usage limit is met. A technician reconditions the surgical instrument 2110 and releases the lockout, for example, utilizing a specialized technician key configured to reset the usage cycle circuit 2102.

[0147] In some aspects, the segmented circuit 2000 is configured for sequential start-up. An error check is performed by each circuit segment 2002a-2002g prior to energizing the next sequential circuit segment 2002a-2002g. FIG. 23 illustrates one example of a process for sequentially energizing a segmented circuit 2270, such as, for example, the segmented circuit 2000. When a battery 2008 is coupled to the segmented circuit 2000, the safety processor 2004 is energized 2272. The safety processor 2004 performs a self-error check 2274. When an error is detected 2276a, the safety processor stops energizing the segmented circuit 2000 and generates an error code 2278a. When no errors are detected 2276b, the safety processor 2004 initiates 2278b power-up of the primary processor 2006. The primary processor 2006 performs a self-error check. When no errors are detected, the primary processor 2006 begins sequential power-up of each of the remaining circuit segments 2278b. Each circuit segment is energized and error checked by the primary processor 2006. When no errors are detected, the next circuit segment is energized 2278b. When an error is detected, the safety processor 2004 and/or the primary process stops energizing the current segment and generates an error 2278a. The sequential start-up continues until all of the circuit segments 2002a-2002g have been energized.

[0148] FIG. 24 illustrates one aspect of a power segment 2302 comprising a plurality of daisy chained power converters 2314, 2316, 2318. The power segment 2302 comprises a battery 2308. The battery 2308 is configured to provide a source voltage, such as, for example, 12V. A current sensor 2312 is coupled to the battery 2308 to monitor the current draw of a segmented circuit and/or one or more circuit segments. The current sensor 2312 is coupled to an FET switch 2313. The battery 2308 is coupled to one or more voltage converters 2309, 2314, 2316. An always on converter 2309 provides a constant voltage to one or more circuit components, such as, for example, a motion sensor 2322. The always on converter 2309 comprises, for example, a 3.3V converter. The always on converter 2309 may provide a constant voltage to additional circuit components, such as, for example, a safety processor (not shown). The battery 2308 is coupled to a boost converter 2318. The boost converter 2318 is configured to provide a boosted voltage above the voltage provided by the battery 2308. For example, in the illustrated example, the battery 2308 provides a voltage of 12V. The boost converter 2318 is configured to boost the voltage to 13 V. The boost converter 2318 is configured to maintain a minimum voltage during operation of a surgical instrument, for example, the surgical instrument 10 (FIGS. 1-4). Operation of a motor can result in the power provided to the primary processor 2306 dropping below a minimum threshold and creating a brownout or reset condition in the primary processor 2306. The boost converter 2318 ensures that sufficient power is available to the primary processor 2306 and/or other circuit components, such as the motor controller 2343, during operation of the surgical instrument 10. In some examples, the boost converter 2318 is coupled directly one or more circuit components, such as, for example, an OLED display 2388.

[0149] The boost converter 2318 is coupled to one or more step-down converters to provide voltages below the boosted voltage level. A first voltage converter 2316 is coupled to the boost converter 2318 and provides a first stepped-down voltage to one or more circuit components. In the illustrated example, the first voltage converter 2316 provides a voltage of 5 V. The first voltage converter 2316 is coupled to a rotary position encoder 2340. A FET switch 2317 is coupled between the first voltage converter 2316 and the rotary position encoder 2340. The FET switch 2317 is controlled by the processor 2306. The processor 2306 opens the FET switch 2317 to deactivate the position encoder 2340, for example, during power intensive operations. The first voltage converter 2316 is coupled to a second voltage converter 2314 configured to provide a second stepped-down voltage. The second stepped-down voltage comprises, for example, 3.3V. The second voltage converter 2314 is coupled to a processor 2306. In some examples, the boost converter 2318, the first voltage converter 2316, and the second voltage converter 2314 are coupled in a daisy chain configuration. The daisy chain configuration allows the use of smaller, more efficient converters for generating voltage levels below the boosted voltage level. The examples, however, are not limited to the particular voltage range(s) described in the context of this specification.

[0150] FIG. 25 illustrates one aspect of a segmented circuit 2400 configured to maximize power available for critical and/or power intense functions. The segmented circuit 2400 comprises a battery 2408. The battery 2408 is configured to provide a source voltage such as, for example, 12V. The source voltage is provided to a plurality of voltage converters 2409, 2418. An always-on voltage converter 2409 provides a constant voltage to one or more circuit components, for example, a motion sensor 2422 and a safety processor 2404. The always-on voltage converter 2409 is directly coupled to the battery 2408. The always-on converter 2409 provides a voltage of 3.3V, for example. The examples, however, are not limited to the particular voltage range(s) described in the context of this specification.

[0151] The segmented circuit 2400 comprises a boost converter 2418. The boost converter 2418 provides a boosted voltage above the source voltage provided by the battery 2408, such as, for example, 13 V. The boost converter 2418 provides a boosted voltage directly to one or more circuit components, such as, for example, an OLED display 2488 and a motor controller 2443. By coupling the OLED display 2488 directly to the boost converter 2418, the segmented circuit 2400 eliminates the need for a power converter dedicated to the OLED display 2488. The boost converter 2418 provides a boosted voltage to the motor controller 2443 and the motor 2448 during one or more power intensive operations of the motor 2448, such as, for example, a cutting operation. The boost converter 2418 is coupled to a step-down converter 2416. The step-down converter 2416 is configured to provide a voltage below the boosted voltage to one or more circuit components, such as, for example, 5V. The step-down converter 2416 is coupled to, for example, a FET switch 2451 and a position encoder 2440. The FET switch 2451 is coupled to the primary processor 2406. The primary processor 2406 opens the FET switch 2451 when transitioning the segmented circuit 2400 to sleep mode and/or during power intensive functions requiring additional voltage delivered to the motor 2448. Opening the FET switch 2451 deactivates the position encoder 2440 and eliminates the power draw of the position encoder 2440. The examples, however, are not limited to the particular voltage range(s) described in the context of this specification.

[0152] The step-down converter 2416 is coupled to a linear converter 2414. The linear converter 2414 is configured to provide a voltage of, for example, 3.3V. The linear converter 2414 is coupled to the primary processor 2406. The linear converter 2414 provides an operating voltage to the primary processor 2406. The linear converter 2414 may be coupled to one or more additional circuit components. The examples, however, are not limited to the particular voltage range(s) described in the context of this specification.

[0153] The segmented circuit 2400 comprises a bailout switch 2456. The bailout switch 2456 is coupled to a bailout door on the surgical instrument 10. The bailout switch 2456 and the safety processor 2404 are coupled to an AND gate 2419. The AND gate 2419 provides an input to a FET switch 2413. When the bailout switch 2456 detects a bailout condition, the bailout switch 2456 provides a bailout shutdown signal to the AND gate 2419. When the safety processor 2404 detects an unsafe condition, such as, for example, due to a sensor mismatch, the safety processor 2404 provides a shutdown signal to the AND gate 2419. In some examples, both the bailout shutdown signal and the shutdown signal are high during normal operation and are low when a bailout condition or an unsafe condition is detected. When the output of the AND gate 2419 is low, the FET switch 2413 is opened and operation of the motor 2448 is prevented. In some examples, the safety processor 2404 utilizes the shutdown signal to transition the motor 2448 to an off state in sleep mode. A third input to the FET switch 2413 is provided by a current sensor 2412 coupled to the battery 2408. The current sensor 2412 monitors the current drawn by the circuit 2400 and opens the FET switch 2413 to shut-off power to the motor 2448 when an electrical current above a predetermined threshold is detected. The FET switch 2413 and the motor controller 2443 are coupled to a bank of FET switches 2445 configured to control operation of the motor 2448.

[0154] A motor current sensor 2446 is coupled in series with the motor 2448 to provide a motor current sensor reading to a current monitor 2447. The current monitor 2447 is coupled to the primary processor 2406. The current monitor 2447 provides a signal indicative of the current draw of the motor 2448. The primary processor 2406 may utilize the signal from the motor current 2447 to control operation of the motor, for example, to ensure the current draw of the motor 2448 is within an acceptable range, to compare the current draw of the motor 2448 to one or more other parameters of the circuit 2400 such as, for example, the position encoder 2440, and/or to determine one or more parameters of a treatment site. In some examples, the current monitor 2447 may be coupled to the safety processor 2404.

[0155] In some aspects, actuation of one or more handle controls, such as, for example, a firing trigger, causes the primary processor 2406 to decrease power to one or more components while the handle control is actuated. For example, in one example, a firing trigger controls a firing stroke of a cutting member. The cutting member is driven by the motor 2448. Actuation of the firing trigger results in forward operation of the motor 2448 and advancement of the cutting member. During firing, the primary processor 2406 opens the FET switch 2451 to remove power from the position encoder 2440. The deactivation of one or more circuit components allows higher power to be delivered to the motor 2448. When the firing trigger is released, full power is restored to the deactivated components, for example, by closing the FET switch 2451 and reactivating the position encoder 2440.

[0156] In some aspects, the safety processor 2404 controls operation of the segmented circuit 2400. For example, the safety processor 2404 may initiate a sequential power-up of the segmented circuit 2400, transition of the segmented circuit 2400 to and from sleep mode, and/or may override one or more control signals from the primary processor 2406. For example, in the illustrated example, the safety processor 2404 is coupled to the step-down converter 2416. The safety processor 2404 controls operation of the segmented circuit 2400 by activating or deactivating the step-down converter 2416 to provide power to the remainder of the segmented circuit 2400.

[0157] FIG. 26 illustrates one aspect of a power system 2500 comprising a plurality of daisy chained power converters 2514, 2516, 2518 configured to be sequentially energized. The plurality of daisy chained power converters 2514, 2516, 2518 may be sequentially activated by, for example, a safety processor during initial power-up and/or transition from sleep mode. The safety processor may be powered by an independent power converter (not shown). For example, in one example, when a battery voltage VBATT is coupled to the power system 2500 and/or an accelerometer detects movement in sleep mode, the safety processor initiates a sequential start-up of the daisy chained power converters 2514, 2516, 2518. The safety processor activates the 13V boost section 2518. The boost section 2518 is energized and performs a self-check. In some examples, the boost section 2518 comprises an integrated circuit 2520 configured to boost the source voltage and to perform a self check. A diode D prevents power-up of a 5 V supply section 2516 until the boost section 2518 has completed a self-check and provided a signal to the diode D indicating that the boost section 2518 did not identify any errors. In some examples, this signal is provided by the safety processor. The examples, however, are not limited to the particular voltage range(s) described in the context of this specification.

[0158] The 5V supply section 2516 is sequentially powered-up after the boost section 2518. The 5V supply section 2516 performs a self-check during power-up to identify any errors in the 5V supply section 2516. The 5V supply section 2516 comprises an integrated circuit 2515 configured to provide a step-down voltage from the boost voltage and to perform an error check. When no errors are detected, the 5 V supply section 2516 completes sequential power-up and provides an activation signal to the 3.3V supply section 2514. In some examples, the safety processor provides an activation signal to the 3.3V supply section 2514. The 3.3V supply section comprises an integrated circuit 2513 configured to provide a step-down voltage from the 5 V supply section 2516 and perform a self-error check during power-up. When no errors are detected during the self-check, the 3.3V supply section 2514 provides power to the primary processor. The primary processor is configured to sequentially energize each of the remaining circuit segments. By sequentially energizing the power system 2500 and/or the remainder of a segmented circuit, the power system 2500 reduces error risks, allows for stabilization of voltage levels before loads are applied, and prevents large current draws from all hardware being turned on simultaneously in an uncontrolled manner. The examples, however, are not limited to the particular voltage range(s) described in the context of this specification.

[0159] In one aspect, the power system 2500 comprises an over voltage identification and mitigation circuit. The over voltage identification and mitigation circuit is configured to detect a monopolar return current in the surgical instrument and interrupt power from the power segment when the monopolar return current is detected. The over voltage identification and mitigation circuit is configured to identify ground floatation of the power system. The over voltage identification and mitigation circuit comprises a metal oxide varistor. The over voltage

identification and mitigation circuit comprises at least one transient voltage suppression diode.

[0160] FIG. 27 illustrates one aspect of a segmented circuit 2600 comprising an isolated control section 2602. The isolated control section 2602 isolates control hardware of the segmented circuit 2600 from a power section (not shown) of the segmented circuit 2600. The control section 2602 comprises, for example, a primary processor 2606, a safety processor (not shown), and/or additional control hardware, for example, a FET Switch 2617. The power section comprises, for example, a motor, a motor driver, and/or a plurality of motor MOSFETS. The isolated control section 2602 comprises a charging circuit 2603 and a rechargeable battery 2608 coupled to a 5V power converter 2616. The charging circuit 2603 and the rechargeable battery 2608 isolate the primary processor 2606 from the power section. In some examples, the rechargeable battery 2608 is coupled to a safety processor and any additional support hardware. Isolating the control section 2602 from the power section allows the control section 2602, for example, the primary processor 2606, to remain active even when main power is removed, provides a filter, through the rechargeable battery 2608, to keep noise out of the control section 2602, isolates the control section 2602 from heavy swings in the battery voltage to ensure proper operation even during heavy motor loads, and/or allows for real-time operating system (RTOS) to be used by the segmented circuit 2600. In some examples, the rechargeable battery 2608 provides a stepped-down voltage to the primary processor, such as, for example, 3.3V. The examples, however, are not limited to the particular voltage range(s) described in the context of this specification.

[0161] FIGS. 28A and 28B illustrate another aspect of a control circuit 3000 configured to control the powered surgical instrument 10, illustrated in FIGS. 1-18 A. As shown in FIGS. 18 A, 28B, the handle assembly 14 may include a motor 3014 which can be controlled by a motor driver 3015 and can be employed by the firing system of the surgical instrument 10. In various forms, the motor 3014 may be a DC brushed driving motor having a maximum rotation of, approximately, 25,000 RPM, for example. In other arrangements, the motor 3014 may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. In certain circumstances, the motor driver 3015 may comprise an H-Bridge FETs 3019, as illustrated in FIG. 28B, for example. The motor 3014 can be powered by a power assembly 3006, which can be releasably mounted to the handle assembly 14. The power assembly 3006 is configured to supply control power to the surgical instrument 10. The power assembly 3006 may comprise a battery which may include a number of battery cells connected in series that can be used as the power source to power the surgical instrument 10. In such configuration, the power assembly 3006 may be referred to as a battery pack. In certain circumstances, the battery cells of the power assembly 3006 may be replaceable and/or rechargeable. In at least one example, the battery cells can be Lithium-Ion batteries which can be separably couplable to the power assembly 3006.

[0162] Examples of drive systems and closure systems that are suitable for use with the surgical instrument 10 are disclosed in U.S. Provisional Patent Application Serial No. 61/782,866, entitled CONTROL SYSTEM OF A SURGICAL INSTRUMENT, and filed March 14, 2013, the entire disclosure of which is incorporated by reference herein in its entirety. For example, the electric motor 3014 can include a rotatable shaft (not shown) that may operably interface with a gear reducer assembly that can be mounted in meshing engagement with a set, or rack, of drive teeth on a longitudinally-movable drive member. In use, a voltage polarity provided by the battery can operate the electric motor 3014 to drive the longitudinally-movable drive member to effectuate the end effector 300. For example, the motor 3014 can be configured to drive the longitudinally- movable drive member to advance a firing mechanism to fire staples into tissue captured by the end effector 300 from a staple cartridge assembled with the end effector 300 and/or advance a cutting member to cut tissue captured by the end effector 300, for example.

[0163] As illustrated in FIGS. 28A and 28B and as described below in greater detail, the power assembly 3006 may include a power management controller 3016 which can be configured to modulate the power output of the power assembly 3006 to deliver a first power output to power the motor 3014 to advance the cutting member while the interchangeable shaft assembly 200 is coupled to the handle assembly 14 and to deliver a second power output to power the motor 3014 to advance the cutting member while the interchangeable shaft assembly 200 is coupled to the handle assembly 14, for example. Such modulation can be beneficial in avoiding transmission of excessive power to the motor 3014 beyond the requirements of an interchangeable shaft assembly that is coupled to the handle assembly 14. [0164] The shaft assembly 200 may include the shaft PCBA 3031 which includes the shaft assembly controller 3022 which can communicate with the power management controller 3016 through an interface (e.g., interface 3024 of FIG. 29) while the shaft assembly 200 and the power assembly 3006 are coupled to the handle assembly 14. For example, the interface may comprise a first interface portion 3025 which may include one or more electric connectors for coupling engagement with corresponding shaft assembly electric connectors and a second interface portion 3027 which may include one or more electric connectors for coupling engagement with

corresponding power assembly electric connectors to permit electrical communication between the shaft assembly controller 3022 and the power management controller 3016 while the shaft assembly 200 and the power assembly 3006 are coupled to the handle assembly 14. One or more

communication signals can be transmitted through the interface to communicate one or more of the power requirements of the attached interchangeable shaft assembly 200 to the power management controller 3016. In response, the power management controller 3016 may modulate the power output of the battery of the power assembly 3006, as described below in greater detail, in accordance with the power requirements of the attached shaft assembly 200. In certain

circumstances, one or more of the electric connectors may comprise switches which can be activated after mechanical coupling engagement of the handle assembly 14 to the shaft assembly 200 and/or to the power assembly 3006 to allow electrical communication between the shaft assembly controller 3022 and the power management controller 3016.

[0165] In certain circumstances, the interface can facilitate transmission of the one or more communication signals between the power management controller 3016 and the shaft assembly controller 3022 by routing such communication signals through a main controller 3017 residing in the handle assembly 14, for example. In other circumstances, the interface can facilitate a direct line of communication between the power management controller 3016 and the shaft assembly controller 3022 through the handle assembly 14 while the shaft assembly 200 and the power assembly 3006 are coupled to the handle assembly 14.

[0166] In one instance, the main microcontroller 3017 may be any single core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. In one instance, the surgical instrument 10 (FIGS. 1-4) may comprise a power management controller 3016 such as, for example, a safety microcontroller platform comprising two microcontroller-based families such as TMS570 and RM4x known under the trade name Hercules ARM Cortex R4, also by Texas Instruments. Nevertheless, other suitable substitutes for microcontrollers and safety processor may be employed, without limitation. In one instance, the safety processor 2004 (FIG. 21A) may be configured specifically for IEC 61508 and ISO 26262 safety critical applications, among others, to provide advanced integrated safety features while delivering scalable performance, connectivity, and memory options.

[0167] In certain instances, the microcontroller 3017 may be an LM 4F230H5QR, available from Texas Instruments, for example. In at least one example, the Texas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Core comprising on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle serial random access memory (SRAM), internal read-only memory (ROM) loaded with StellarisWare® software, 2KB electrically erasable programmable read-only memory (EEPROM), one or more pulse width modulation (PWM) modules, one or more quadrature encoder inputs (QEI) analog, one or more 12-bit Analog-to-Digital Converters (ADC) with 12 analog input channels, among other features that are readily available for the product datasheet. The present disclosure should not be limited in this context.

[0168] The power assembly 3006 may include a power management circuit which may comprise the power management controller 3016, a power modulator 3038, and a current sense circuit 3036. The power management circuit can be configured to modulate power output of the battery based on the power requirements of the shaft assembly 200 while the shaft assembly 200 and the power assembly 3006 are coupled to the handle assembly 14. For example, the power management controller 3016 can be programmed to control the power modulator 3038 of the power output of the power assembly 3006 and the current sense circuit 3036 can be employed to monitor power output of the power assembly 3006 to provide feedback to the power management controller 3016 about the power output of the battery so that the power management controller 3016 may adjust the power output of the power assembly 3006 to maintain a desired output.

[0169] It is noteworthy that the power management controller 3016 and/or the shaft assembly controller 3022 each may comprise one or more processors and/or memory units which may store a number of software modules. Although certain modules and/or blocks of the surgical instrument 10 may be described by way of example, it can be appreciated that a greater or lesser number of modules and/or blocks may be used. Further, although various instances may be described in terms of modules and/or blocks to facilitate description, such modules and/or blocks may be implemented by one or more hardware components, e.g., processors, Digital Signal Processors (DSPs),

Programmable Logic Devices (PLDs), Application Specific Integrated Circuits (ASICs), circuits, registers and/or software components, e.g., programs, subroutines, logic and/or combinations of hardware and software components.

[0170] In certain instances, the surgical instrument 10 may comprise an output device 3042 which may include one or more devices for providing a sensory feedback to a user. Such devices may comprise, for example, visual feedback devices (e.g., an LCD display screen, LED indicators), audio feedback devices (e.g., a speaker, a buzzer) or tactile feedback devices (e.g., haptic actuators). In certain circumstances, the output device 3042 may comprise a display 3043 which may be included in the handle assembly 14. The shaft assembly controller 3022 and/or the power management controller 3016 can provide feedback to a user of the surgical instrument 10 through the output device 3042. The interface (e.g. interface 3024 of FIG. 29) can be configured to connect the shaft assembly controller 3022 and/or the power management controller 3016 to the output device 3042. The reader will appreciate that the output device 3042 can instead be integrated with the power assembly 3006. In such circumstances, communication between the output device 3042 and the shaft assembly controller 3022 may be accomplished through the interface while the shaft assembly 200 is coupled to the handle assembly 14.

[0171] FIG. 29 is a block diagram the surgical instrument of FIG. 1 illustrating interfaces

(collectively 3024) between the handle assembly 14 and the power assembly 3006 and between the handle assembly 14 and the interchangeable shaft assembly 200. As shown in FIG. 29, the power assembly 3006 may include a power management circuit 3034 which may comprise the power management controller 3016, a power modulator 3038, a current sense circuit 3036 and a power assembly connector 3032. The power management circuit 3034 can be configured to modulate power output of the battery 3007 based on the power requirements of the shaft assembly 200 while the shaft assembly 200 and the power assembly 3006 are coupled to the handle assembly 14. For example, the power management controller 3016 can be programmed to control the power modulator 3038 of the power output of the power assembly 3006 and the current sense circuit 3036 can be employed to monitor power output of the power assembly 3006 to provide feedback to the power management controller 3016 about the power output of the battery 3007 so that the power management controller 3016 may adjust the power output of the power assembly 3006 to maintain a desired output. The power assembly connector 3032 is configured to connect to the power assembly connector 3030 of the handle assembly 14 at the interface 3027 to connect the power assembly 3006 to the handle assembly 14. [0172] The shaft assembly 200 includes the shaft assembly controller 3022 and a shaft assembly connector 3028. The shaft assembly connector 3028 is configured to connect to the shaft assembly connector 3026 of the handle assembly 14 at the interface 3025 to connect the shaft assembly 200 to the handle assembly 14. As shown in FIG. 29, the handle assembly 14 may include the main microcontroller 3017 and the output device 3042 which comprises the display 3043.

[0173] As described hereinabove, various components may cooperate to assist in the control of a motor of a powered surgical instrument. For example, for the powered surgical instrument 10, the motor current sensor 2046 measures the current being delivered to the motor 2048 and delivers an input signal representative of the measured current to the main processor 2006, which in turn applies pulse width modulation signals to the motor controller 2043, which in turn provides control signals to the gate terminals of the FETS 2044 to control the amount of current delivered to the motor 2048 over time from the battery 2008, as well as the direction of rotation of the motor 2048. One motor current sensor 2046 may be utilized to measure the current being delivered to the motor 2048 when the motor is rotating in a first direction and another motor current sensor 2046 may be utilized to measure the current being delivered to the motor 2048 when the motor is rotating in a second direction. Collectively, such components may be considered to form a portion of a control circuit/system or a motor control circuit/system. In various embodiments, in order to measure the current being delivered to the motor 2048, the motor current sensor 2046 is positioned to measure the current flowing in the H-bridge circuit (the H-bridge circuit includes the FETS 2044 and allows a voltage to be applied across the motor 2048 in either direction to allow the motor 2048 to rotate in a first direction and a second direction) between the motor 2048 and a FET 2044 which is upstream to the motor 2048. The measured current can be utilized to control the motor 2048, and by extension, to control a force applied to the firing drive system 80 of the powered surgical instrument 10.

[0174] In practice, it is relatively difficult to position a motor current sensor 2046 to measure the current flowing in the H-bridge circuit between the motor 2048 and a FET 2044 which is upstream to the motor 2048. Therefore, according to various embodiments, it is desired to utilize a current other than the current measured in the H-bridge circuit to control the motor 2048. For example, in lieu of utilizing the current measured in the H-bridge circuit as described hereinabove, an out-of- phase current downstream of the H-bridge can be utilized to control the motor 2048.

[0175] FIG. 30 illustrates a simplified representation of various embodiments of a surgical stapler 3100. According to various embodiments, the surgical stapler 3100 includes a drive system, an electric motor 3102, a battery 3104, and a control system. The drive system, which is not shown in FIG. 30 for purposes of simplicity, may be similar or identical to the firing drive system 80. The electric motor 3102 is mechanically coupled to the drive system, and may be similar or identical to the motor 2048. The battery 3104 is electrically couplable to the electric motor 3102, and may be similar or identical to the battery 2008. The control system is electrically connected to the electric motor 3102, and includes an H-bridge circuit, a first inductive element 3120, a second inductive element 3122, a first resistive element 3124, a second resistive element 3126, a first sensor 3128 and a second sensor 3130. The H-bridge circuit which includes a first switching device 3110, a second switching device 3112, a third switching device 3114 and a fourth switching device 3116. The first, second, third and fourth switching devices 3110-3116 may be any suitable type of switching devices, and may be similar or identical to the FETS 2044. The H-bridge circuit also defines a high side and a low side relative to the electric motor 3102. The high side includes first and second legs, with the first switching device 3110 being part of the first leg and the second switching device 3112 being part of the second leg. The low side includes third and fourth legs, with the third switching device 3114 being part of the third leg and the fourth switching device 316 being part of the fourth leg. The high side of the H-bridge circuit is considered the upstream side of the H-bridge circuit and the low side of the H-bridge circuit is considered the downstream side of the H-bridge circuit. The electric motor 3102 is electrically couplable to the battery 3104 via the H- bridge circuit.

[0176] The first inductive element 3120 is electrically connected in series with the fourth switching device 3116, downstream of the fourth switching device 3116. The first inductive element 3120 may be embodied as any suitable type of inductive element. For example, according to various embodiments, the first inductive element 3120 may be embodied as an inductor. Although the first inductive element 3120 is shown as a single inductor, it will be appreciated that the first inductive element 3120 may include any number of inductive elements. The second inductive element 3122 is electrically connected in series with the third switching device 3114, downstream of the third switching device 3114. The second inductive element 3122 may be embodied as any suitable type of inductive element. For example, according to various embodiments, the second inductive element 3122 may be embodied as an inductor. Although the second inductive element 3122 is shown as a single inductor, it will be appreciated that the second inductive element 3122 may include any number of inductive elements. The first and second inductive elements 3120, 3122 may be the same or different, and may embodied as any suitable type of inductive element. For example, the first and second inductive elements 3120, 3122 may be embodied as inductors and the inductors may have the same or different henry values.

[0177] The first resistive element 3124 is electrically connected in series with the first inductive element 3120. The first resistive element 3124 may be embodied as any suitable type of resistive element. For example, according to various embodiments, the first resistive element 3124 may be embodied as a resistor. Although the first resistive element 3124 is shown as a single resistor, it will be appreciated that the first resistive element 3124 may include any number of resistive elements. The second resistive element 3126 is electrically connected in series with the second inductive element 3122. The second resistive element 3126 may be embodied as any suitable type of resistive element. For example, according to various embodiments, the second resistive element 3126 may be embodied as a resistor. Although the second resistive element 3126 is shown as a single resistor, it will be appreciated that the second resistive element 3126 may include any number of resistive elements. The first and second resistive elements 3124, 3126 may be the same or different, and may embodied as any suitable type of resistive element. For example, as shown in according to various embodiments, the first and second resistive elements 3124, 3126 may be embodied as resistors, and the resistors may have the same or different ohm values.

[0178] The first sensor 3128 may be positioned proximate the first resistive element 3124 and is configured to sense/measure a current entering, passing through, exiting from or downstream of the first resistive element 3124. The first sensor 3124 may be any suitable type of sensor configured to sense/measure a current. The second sensor 3130 may be positioned proximate the second resistive element 3126 and is configured to sense/measure a current entering, passing through, exiting from or downstream of the second resistive element 3126. The second sensor 3126 may be any suitable type of sensor configured to sense/measure a current.

[0179] In operation, when the first and fourth switching devices 3110, 3116 are "closed" and the second and third switching devices 3112, 3114 are "open", the electric motor 3102 is able to draw current from the battery 3104 and rotate in a first direction (e.g., a direction which causes a component of the drive system to advance distally). For this condition, the path of the current is from the positive terminal of the battery 3104, through the first switching device 3110, through the electric motor 3102, through the fourth switching device 3116, through the first inductive element 3120, through the first resistive element 3124 and back to the negative terminal of the battery 3104. Initially, the current through the first inductive element 3120 is zero, then it increases over time until it is equal to the battery voltage divided by the series resistance between the battery 3104 and the first inductive element 3120. In other words, the first inductive element 3120 initially resists any change in the current flowing through the first inductive element 3120. Due to the variation in the amount of current flowing through the first inductive element 3120 over time, the current flowing through the first resistive element 3124 will also vary over time, initially starting at zero then increasing over time until it is equal to the battery voltage divided by the series resistance between the battery 3104 and the first resistive element 3124. The current flowing through the first resistive element 3124 may be sensed/measured by the first sensor 3128. Responsive to the sensed current, the first sensor 3128 may output a signal which is indicative of the magnitude of the sensed current. The output signal from the first sensor 3128 may be input to the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler 3100 when the electric motor 3102 is operating in the first direction.

[0180] Similarly, when the second and third switching devices 3112, 3114 are "closed" and the first and fourth switching devices 3110, 3116 are "open", the electric motor 3102 is able to draw current from the battery 3104 and rotate in a second direction (e.g., a direction which causes a component of the drive system to retract proximally). For this condition, the path of the current is from the positive terminal of the battery 3104, through the second switching device 3112, through the electric motor 3102, through the third switching device 3114, through the second inductive element 3122, through the second resistive element 3126 and back to the negative terminal of the battery 3104. Initially, the current through the second inductive element 3122 is zero, then it increases over time until it is equal to the battery voltage divided by the series resistance between the battery 3104 and the second inductive element 3122. In other words, the second inductive element 3122 initially resists any change in the current flowing through the second inductive element 3122. Due to the variation in the amount of current flowing through the second inductive element 3122 over time, the current flowing through the second resistive element 3126 will also vary over time, initially starting at zero then increasing over time until it is equal to the battery voltage divided by the series resistance between the battery 3104 and the second resistive element 3126. The current flowing through the second resistive element 3126 may be sensed/measured by the second sensor 3130. Responsive to the sensed current, the second sensor 3130 may output a signal which is indicative of the magnitude of the sensed current. The output signal from the second sensor 3130 may be input to the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler 3100 when the electric motor 3102 is operating in the second direction. [0181] Although the surgical stapler 3100 is only shown in FIG. 30 as having an inductive element and a resistive element downstream of each lower leg of the H-bridge circuit, it will be appreciated that according to other embodiments, the surgical stapler 3100 may include a single inductive element / resistive element pair electrically connected downstream of either the third leg or the fourth leg of the H-bridge circuit. Additionally, according to other embodiments, other

combinations/arrangements of electrical components may be electrically connected downstream of the lower legs of the H-bridge circuit.

[0182] FIG. 31 illustrates a simplified representation of various embodiments of a surgical stapler 3200. The surgical stapler 3200 is similar to the surgical stapler 3100, but is different in that the surgical stapler 3200 includes a different combination and arrangement of electrical components downstream of the lower legs of the H-bridge circuit. The surgical stapler 3200 includes first and second inductive elements 3220, 3222, first and second resistive elements 3224, 3226, first and second sensors 3228, 3230 and first and second capacitive elements 3232, 3234. The first and second inductive elements 3220, 3222 may be similar or identical to the first and second inductive elements 3120, 3122. The first and second resistive elements 3224, 3226 may be similar or identical to first and second resistive elements 3124, 3126. The first and second sensors 3228, 3230 may be similar or identical to the first and second sensors 3128, 3130. For example, according to various embodiments, the first and second sensors 3228, 3230 may be configured to sense/measure a current. According to other embodiments, the first and second sensors 3228, 3230 may be configured to sense a voltage. According to yet other embodiments, the first and second sensors 3228, 3230 may be configured to sense a current and/or a voltage.

[0183] The first capacitive element 3232 is electrically connected in series with the first inductive element 3220 and in parallel with the first resistive element 3224. The first capacitive element 3232 may be embodied as any suitable type of capacitive element. For example, according to various embodiments, the first capacitive element 3232 may be embodied as a capacitor. Although the first capacitive element 3232 is shown as a single capacitor, it will be appreciated that the first capacitive element 3232 may include any number of capacitive elements. The second capacitive element 3234 is electrically connected in series with the second inductive element 3222 and in parallel with the second resistive element 3226. The second capacitive element 3234 may be embodied as any suitable type of capacitive element. For example, according to various embodiments, the second capacitive element 3234 may be embodied as a capacitor. Although the second capacitive element 3234 is shown as a single capacitor, it will be appreciated that the second capacitive element 3234 may include any number of capacitive elements. The first and second capacitive elements 3232, 3234 may be the same or different, and may embodied as any suitable type of capacitive element. For example, according to various embodiments, the first and second capacitive elements 3232, 3234 may be embodied as capacitors, and the capacitors may have the same or different farad values.

[0184] In operation, when the first and fourth switching devices 3110, 3116 are "closed" and the second and third switching devices 3112, 3114 are "open", the electric motor 3102 is able to draw current from the battery 3104 and rotate in a first direction (e.g., a direction which causes a component of the drive system to advance distally). For this condition, the path of the current is from the positive terminal of the battery 3104, through the first switching device 3110, through the electric motor 3102, through the fourth switching device 3116, through both the first resistive element 3224 and the first inductive element 3220 / first capacitance element 3232 pair, and back to the negative terminal of the battery 3104. Initially, the current through the first inductive element 3220 is zero, then it increases over time until it is equal to the battery voltage divided by the series resistance between the battery 3104 and the first inductive element 3220. Due to the variation in the amount of current flowing through the first inductive element 3220 over time, the current flowing through the first capacitive element 3232 will also vary over time, initially starting at zero then increasing over time until it is equal to the battery voltage divided by the series resistance between the battery 3104 and the first capacitive element 3232. The current downstream of the first capacitance element 3232 (or downstream of the first resistive element 3224) may be

sensed/measured by the first sensor 3228. Responsive to the sensed current, the first sensor 3228 may output a signal which is indicative of the magnitude of the sensed current. The output signal from the first sensor 3228 may be input to the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler 3100 when the electric motor 3102 is operating in the first direction.

[0185] With respect to voltage, initially the voltage across the first capacitive element 3232 is zero, then it increases over time until it is equal to the battery voltage less any voltage drops between the battery 3104 and the first capacitive element 3232. In other words, the first capacitive element 3232 initially resists any change in the voltage across it. Thus, there is a variation in the amount of voltage across the first capacitive element 3232 over time, initially starting at zero then increasing over time until it is equal to the battery voltage less any voltage drops between the battery 3104 and the first capacitive element 3232. By measuring a voltage across the first capacitive element 3232 while the electric motor 3102 is operating in the first direction, the measured voltage will have a magnitude which is different than a magnitude of a voltage measured at the electric motor 3102. The voltage across the first capacitive element 3232 may be sensed/measured by a the first sensor 3228. Responsive to the sensed voltage, the first sensor 3228 may output a signal which is indicative of the magnitude of the sensed voltage. The output signal from the first sensor 3228 may be input to the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler 3100 when the electric motor 3102 is operating in the first direction.

[0186] Similarly, when the second and third switching devices 3112, 3114 are "closed" and the first and fourth switching devices 3110, 3116 are "open", the electric motor 3102 is able to draw current from the battery 3104 and rotate in a second direction (e.g., a direction which causes a component of the drive system to retract proximally). For this condition, the path of the current is from the positive terminal of the battery 3104, through the second switching device 3112, through the electric motor 3102, through the third switching device 3114, through both the second resistive element 3226 and the second inductive element 3222 / second capacitance element 3234 pair, and back to the negative terminal of the battery 3104. Initially, the current through the second inductive element 3222 is zero, then it increases over time until it is equal to the battery voltage divided by the series resistance between the battery 3104 and the second inductive element 3222. Due to the variation in the amount of current flowing through the second inductive element 3222 over time, the current flowing through the second capacitive element 3234 will also vary over time, initially starting at zero then increasing over time until it is equal to the battery voltage divided by the series resistance between the battery 3104 and the second capacitive element 3234. The current downstream of the second capacitance element 3234 (or downstream of the second resistive element 3226) may be sensed/measured by the second sensor 3230. Responsive to the sensed current, the second sensor 3230 may output a signal which is indicative of the magnitude of the sensed current. The output signal from the second sensor 3230 may be input to the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler 3100 when the electric motor 3102 is operating in the second direction.

[0187] With respect to voltage, initially the voltage across the second capacitive element 3234 is zero, then it increases over time until it is equal to the battery voltage less any voltage drops between the battery 3104 and the second capacitive element 3234. In other words, the second capacitive element 3234 initially resists any change in the voltage across it. Thus, there is a variation in the amount of voltage across the second capacitive element 3234 over time, initially starting at zero then increasing over time until it is equal to the battery voltage less any voltage drops between the battery 3104 and the second capacitive element 3234. By measuring a voltage across the second capacitive element 3234 while the electric motor 3102 is operating in the second direction, the measured voltage will have a magnitude which is different than a magnitude of a voltage measured at the electric motor 3102. The voltage across the second capacitive element 3234 may be sensed/measured by the second sensor 3230. Responsive to the sensed voltage, the second sensor 3230 may output a signal which is indicative of the magnitude of the sensed voltage. The output signal from the second sensor 3230 may be input to the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler 3100 when the electric motor 3102 is operating in the second direction.

[0188] Although the surgical stapler 3200 is only shown in FIG. 31 as having an resistive element and an inductive element / capacitive element pair downstream of each lower leg of the H-bridge circuit, it will be appreciated that according to other embodiments, the surgical stapler 3200 may include a single resistive element and a single inductive element / capacitive element pair electrically connected downstream of either the third leg or the fourth leg of the H-bridge circuit.

[0189] FIG. 32 illustrates a simplified representation of a surgical stapler 3300 according to various embodiments. The surgical stapler 3300 is similar to the surgical stapler 3200, but is different in that the surgical stapler 3200 includes a different combination and arrangement of electrical components downstream of the lower legs of the H-bridge circuit. The surgical stapler 3300 includes first and second inductive elements 3320, 3322, third and fourth inductive elements 3336, 3338, first and second resistive elements 3324, 3326, first and second sensors 3328, 3330 and first and second capacitive elements 3332, 3334. The first and second inductive elements 3320, 3322 may be similar or identical to the first and second inductive elements 3120, 3122. The first and second resistive elements 3324, 3326 may be similar or identical to first and second resistive elements 3124, 3126. The first and second sensors 3328, 3330 may be similar or identical to the first and second sensors 3228, 3230. The first and second capacitive elements 3332, 3334 may be similar or identical to first and second capacitive elements 3232, 3234.

[0190] The first inductive element 3320 is electrically connected in series with the fourth switching device 3116 and is magnetically coupled with the second inductive element 3336. The first and second inductive elements 3320, 3336 may be embodied as coupled inductors or may collectively form a portion of a transformer. The first and second inductive elements 3320, 3336 may be the same or different, and may embodied as any suitable type of inductive element. For example, according to various embodiments, the first and second inductive elements 3320, 3336 may be embodied as inductors, and the inductors may have the same or different henry values. Although the first inductive element 3320 is shown as a single inductor and the second inductive element 3336 is shown as a single inductor, it will be appreciated that the first inductive element 3320 and/or the second inductive element 3336 may each include any number of inductive elements. Similarly, the third inductive element 3322 is electrically connected in series with the third switching device 3114 and is magnetically coupled with the fourth inductive element 3338. The third and fourth inductive elements 3332, 3338 may be embodied as coupled inductors or may collectively form a portion of a transformer. The third and fourth inductive elements 3332, 3338 may be the same or different, and may embodied as any suitable type of inductive element. For example, according to various embodiments, the third and fourth inductive elements 3332, 3338 may be embodied as inductors, and the inductors may have the same or different henry values. Although the third inductive element 3322 is shown as a single inductor and the fourth inductive element 3338 is shown as a single inductor, it will be appreciated that the third inductive element 3322 and/or the fourth inductive element 3338 may each include any number of inductive elements.

[0191] The first resistive element 3324 is electrically connected in series with the second inductive element 3336. The second resistive element 3326 is electrically connected in series with the fourth inductive element 3338. The first capacitive element 3332 is electrically connected in series with the first resistive element 3324. The second capacitive element 3334 is electrically connected in series with the second resistive element 3326. Collectively, the second inductive element 3336, the first resistive element 3324 and the first capacitive element 3332 form a LRC circuit (e.g., a filter) which is magnetically coupled to the first inductive element 3320. The LRC circuit is configured to filter away certain components (e.g., switching currents, harmonics, etc.) of the current exiting the fourth switching device 3116. Similarly, the fourth inductive element 3338, the second resistive element 3326 and the second capacitive element 3334 form a second LRC circuit (e.g., a filter) which is magnetically coupled to the second inductive element 3322. The second LRC circuit is configured to filter away certain components (e.g., switching currents, harmonics, etc.) of the current exiting the third switching device 3114. Although the two filters are shown as LRC circuits, it will be appreciated that according to various embodiments, the three components of each filter may be arranged in a different order (e.g., a RLC circuit), and one filter may be arranged differently than the other filter. [0192] In operation, when the first and fourth switching devices 3110, 3116 are "closed" and the second and third switching devices 3112, 3114 are "open", the electric motor 3102 is able to draw current from the battery 3104 and rotate in a first direction (e.g., a direction which causes a component of the drive system to advance distally). For this condition, the path of the current is from the positive terminal of the battery 3104, through the first switching device 3110, through the electric motor 3102, through the fourth switching device 3116, through first inductive element 3320 and back to the negative terminal of the battery 3104. Initially, the current through the first inductive element 3320 is zero, then it increases over time until it is equal to the battery voltage divided by the series resistance between the battery 3104 and the first inductive element 3320. The varying current passing through the first inductive element 3320 induces a varying electromotive force (EMF) or voltage across the third inductive element 3336. The voltage induces a current in the LRC circuit. The current in the LRC circuit is a "filtered" current in comparison to the current exiting the fourth switching device 3116 and has a magnitude which is different than the magnitude of the current exiting the fourth switching device 3116. The LRC current may be sensed/measured by the first sensing device 3328. Responsive to the sensed LRC current, the first sensor 3328 may output a signal which is indicative of the magnitude of the sensed current. The output signal from the first sensor 3328 may be input to the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler 3100 when the electric motor 3102 is operating in the first direction. Additionally, the voltage across the first capacitive element 3332 will be different than the voltage at the electric motor 3102. The first sensor 3328 may be configured to sense/measure the voltage across the first capacitive element 3332. Responsive to the sensed voltage, the first sensor 3328 may output a signal which is indicative of the magnitude of the sensed voltage. The output signal from the first sensor 3328 may be input to the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler 3100 when the electric motor 3102 is operating in the first direction.

[0193] Similarly, when the second and third switching devices 3112, 3114 are "closed" and the first and fourth switching devices 3110, 3116 are "open", the electric motor 3102 is able to draw current from the battery 3104 and rotate in a second direction (e.g., a direction which causes a component of the drive system to retract proximally). For this condition, the path of the current is from the positive terminal of the battery 3104, through the second switching device 3112, through the electric motor 3102, through the third switching device 3114, through second inductive element 3322 and back to the negative terminal of the battery 3104. Initially, the current through the second inductive element 3322 is zero, then it increases over time until it is equal to the battery voltage divided by the series resistance between the battery 3104 and the second inductive element 3322. The varying current passing through the second inductive element 3332 induces a varying electromotive force (EMF) or voltage across the fourth inductive element 3338. The voltage induces a current in the second LRC circuit. The current in the second LRC circuit is a "filtered" current in comparison to the current exiting the third switching device 3114 and has a magnitude which is different than the magnitude of the current exiting the third switching device 3114. The LRC current may be sensed/measured by the second sensing device 3330. Responsive to the sensed LRC current, the second sensor 3330 may output a signal which is indicative of the magnitude of the sensed current. The output signal from the second sensor 3330 may be input to the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler 3100 when the electric motor 3102 is operating in the second direction. Additionally, the voltage across the second capacitive element 3334 will be different than the voltage at the electric motor 3102. The second sensor 3330 may be configured to sense/measure the voltage across the second capacitive element 3334. Responsive to the sensed voltage, the second sensor 3330 may output a signal which is indicative of the magnitude of the sensed voltage. The output signal from the second sensor 3330 may be input to the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler 3100 when the electric motor 3102 is operating in the second direction.

[0194] Although the surgical stapler 330 is shown in FIG. 32 as having two LRC circuits, each coupled to inductive elements which are downstream of different legs on the downstream side of the H-bridge circuit, it will be appreciated that according to other embodiments, the surgical stapler 3300 may include a single LRC circuit coupled to a single inductive element which is downstream of either the third leg or the fourth leg of the H-bridge circuit.

[0195] For each of the surgical staplers/instruments described hereinabove, both battery current and recirculation current flows in the H-bridge circuit. An example of battery current and recirculation current waveforms are shown in FIG. 33. In general, when a pulse width modulation circuit of the surgical stapler (e.g., a pulse width modulation circuit of the main processor 2006) provides a high signal (e.g., a voltage signal which is above a baseline value) to the motor controller 2043, the motor controller 2043 controls the switching devices in the H-bridge circuit such that a voltage is applied from the battery 3104 to the electric motor 3102. The electric motor 3102 draws and increasing amount of current from the battery 3104, eventually causing the battery 3104 to rotate. The increasing battery current is shown as the "A" portions of FIG. 33. When the pulse width modulation circuit of the surgical stapler transitions from providing a high signal to providing a low signal (e.g., a voltage signal which is not above a baseline value) to the motor controller 2043, the motor controller 2043 controls the switching devices in the H-bridge circuit voltage such that no voltage is applied to the electric motor 3102 from the battery 3104. When the voltage applied by the battery 3104 is interrupted, the electric motor 3102 does not draw any current from the battery 3104. However, because the electric motor 3102 was rotating, the electric motor 3102 acts like a generator while the electric motor 3102 is still rotating. While the electric motor 3102 is acting like a generator, the electric motor 3102 produces a recirculation current which gradually diminishes to zero. The diminishing recirculation current is shown as the "B" portions of FIG. 33. The shape of the recirculation curve can vary based on the inductance of the electric motor 3102 and the resistance of the recirculation loop.

[0196] Therefore, in order to measure the total average current in the H-bridge, both battery current and recirculation current are measured. Although the battery current can be sensed relatively easily by a current sensor (e.g., current sensor 2012) positioned proximate the battery 3104, the current sensor positioned proximate the battery 3104 will not sense the recirculating current. Although a current sensor positioned to sense a current in the H-bridge proximate the electric motor 3102 would sense the recirculation current, as indicated hereinabove it is relatively difficult to position a current sensor in the H-bridge circuit.

[0197] According to various embodiments, each of the above-described surgical staplers may be configured to utilize predicted recirculation current values to determine an average total current associated with the electric motor 3102, and the average total current may be utilized to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler when the motor is operating in the first or second direction. For such embodiments, the control system includes a battery current sensor positioned to sense the battery current, and the control system is configured to predict recirculating current values based on the sensed battery current.

[0198] The recirculation current may be predicted from the measured battery current in any suitable manner. For example, according to various embodiments, the recirculation current may be predicted based on a characterization of the battery current. For example, the recirculation current may be predicted in the following manner. First, the battery current sensor of the control system takes a plurality of battery current measurements while a pulse signal generated by the pulse width modulation circuit is "high" (above a baseline value). Such samples are indicated by the dots shown on the "A" portions of FIG. 33. Second, the control system (e.g., the main processor 2006) fits the battery current measurements to a first curve representative of the following equation: where V _B is the battery voltage, R is the resistance, t is the time and L is the inductance. The values for the resistance R and the inductance L are known and stored in the handle assembly 14. The above equation is representative of a charging current curve for an inductor (e.g., the motor). At t=0, the current 1 = 0. As t approaches infinity, the current I = VB/R. Third, given the measured battery current I, the control system (e.g., the main processor 2006) determines the value of V _B . Fourth, the control system (e.g., the main processor 2006) utilizes the value of VB as determined above in the following equation to predict values of the recirculating current at various times while the pulse signal is not high:

where R is the resistance, t is the time and L is the inductance. The values for the resistance R and the inductance L are known and stored in the handle assembly 14. The above equation is representative of the discharge current curve for an inductor (e.g., the motor). At t=0, the current I = V _B /R. As t approaches infinity, the current 1 = 0.

[0199] Once the recirculating current values are predicted as described above, the control system (e.g., the main processor 2006) fits the recirculating current values to a second curve representative of the following equation:

where R is the resistance, t is the time and L is the inductance. The values for the resistance R and the inductance L are known and stored in the handle assembly 14. Next, the control system (e.g., the main processor 2006) determines the intersection of the first and second curves. The intersection is representative of an inflection point of a curve which includes a battery current component and a recirculating curve component. From this point, the control system (e.g., the main processor 2006) determines the area under the first curve up to the intersection and the area under the second curve after the intersection. Next, the control system (e.g., the main processor 2006) adds the areas under the first and second curves to determine the average total current at the motor 3102. Finally, the determined average total current at the motor 3102 may be input to or utilized by the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler when the motor is operating in the first or second direction.

[0200] According to other embodiments, the recirculation current may be predicted based on a characterization of the peaks of the measured battery current. For example, the recirculation current may be predicted in the following manner. First, the battery current sensor of the control system takes a plurality of battery current measurements over multiple periods of the PWM duty cycle. An example of such sampling is shown in FIG. 34, where the dots represent the sampled battery current. During recirculation, the battery current is zero. Second, the control system (e.g., the main processor 2006) pulls out the maximum value of the samples (in FIG. 34, the sample "M" has the highest value), designates the maximum value as the ending condition of a battery current curve representative of the following equation: where V _B is the battery voltage, R is the resistance, t is the time and L is the inductance, and generates the battery current curve based on the above equation. The values for the resistance R and the inductance L are known and stored in the handle assembly 14. The above equation is representative of a charging current curve for an inductor (e.g., the motor). At t=0, the current 1 = 0. As t approaches infinity, the current I = V _B /R. Third, given the measured battery current I, the control system (e.g., the main processor 2006) determines the value of V _B . Fourth, the control system (e.g., the main processor 2006) also designates the maximum value of the samples as the initial condition of a recirculation current curve representative of the following equation:

where V _B is the determined battery voltage value, R is the resistance, t is the time and L is the inductance, and generates the recirculation current curve based on the above equation. The values for the resistance R and the inductance L are known and stored in the handle assembly 14. From this point, the control system (e.g., the main processor 2006) determines the area under the battery current curve and the area under the recirculation current curve. Next, the control system (e.g. the main processor) adds the areas under the battery current curve and the recirculation current curves to determine the average total current at the motor 3102. Finally, the determined average total current at the motor 3102 may be input to or utilized by the main processor 2006 to control the electric motor 3102, and by extension, to control a force applied to the drive system of the surgical stapler when the motor is operating in the first or second direction. [0201] According to yet other embodiments, in lieu of utilizing the measured battery current and the predicted recirculation current to control the electric motor, the measured battery current and a state of a duty cycle associated with a pulse width modulation circuit may be utilized to control the electric motor, and by extension, to control a force applied to the drive system of the surgical stapler when the electric motor is operating in the first or second direction. For example, the measured battery current and the state of the duty cycle may be utilized in the following manner.

[0202] First, during the manufacturing of the surgical stapler, the surgical stapler is run at increments of PWM duty cycle between 0% and 100%. At each increment of the PWM duty cycle test, a range of loads are applied to the surgical stapler and the current draw from the battery 3104 is also measured. Also, at each increment of the PWM duty cycle test, the measured current draw is tabulated against the PWM duty cycle and the associated load. Based on the tests, a PWM and current versus force lookup table is generated and stored in a memory (e.g., a nonvolatile memory) of the surgical stapler. Second, during the subsequent use of the surgical stapler, the control system of the surgical stapler utilizes pulse width modulation to modulate the voltage applied to the motor to achieve a target force applied by the surgical stapler. To achieve the target force, the state of the PWM duty cycle (e.g., 20%, 30%, etc.) and the value of the measured battery current are input to the lookup table to obtain the actual force being applied by the surgical stapler. Third, the control system compares the actual force to target force and adjusts the PWM duty cycle to increase or decrease the actual force being applied by the surgical stapler as required to achieve the target force.

[0203] According to various embodiments, the PWM and current versus force lookup table is stored in the main processor 2006. For surgical staplers which also include the safety processor 2004, the PWM and current versus force lookup table can be passed to both the main processor 2006 and the safety processor 2004 during manufacturing. For such embodiments, the PWM duty cycle can be communicated from the main processor 2006 to the safety processor 2004 during the use of the surgical stapler. According to other embodiments, the safety processor 2004 could measure the PWM signal issuing from the main processor 2006 and decode it to access the appropriate force value in the PWM and current versus force lookup table.

[0204] Examples

[0205] Example 1 - A surgical stapler is provided. The surgical stapler comprises a drive system, an electric motor mechanically coupled to the drive system, a battery electrically couplable to the electric motor, and a control system electrically connected to the electric motor. The control system comprises an H-bridge circuit, an electrically resistive element, and an electrically inductive element electrically connected to the electrically resistive element. The H-bridge circuit comprises a high side and a low side, wherein the low side of the H-bridge circuit comprises first and second switching devices. The electrically resistive element is electrically connected in series with the first switching device. The control system is configured to control a force applied to the drive system based on a current downstream of the electrically resistive element.

[0206] Example 2 - The surgical stapler of Example 1, wherein the low side of the H-bridge circuit comprises first and second legs, and the electrically resistive element and the electrically inductive element are electrically connected to one of the first and second legs of the H-bridge circuit.

[0207] Example 3 - The surgical stapler of Examples 1 or 2, wherein the electrically inductive element is electrically connected in series with the electrically resistive element.

[0208] Example 4 - The surgical stapler of Examples 1 or 2, wherein the electrically inductive element is electrically connected in parallel with the electrically resistive element.

[0209] Example 5 - The surgical stapler of Examples 1, 2 or 4, further comprising an electrically capacitive element electrically connected in series with the electrically inductive element.

[0210] Example 6 - The surgical stapler of Examples 1, 2, 3, 4 or 5, further comprising, a second electrically resistive element electrically connected in series with the second switching device, and a second electrically inductive element electrically connected to the second electrically resistive element, wherein the control system is further configured to control a second force applied to the drive system based on a second current measured downstream of the second electrically resistive element.

[0211] Example 7 - The surgical stapler of Example 6, wherein the second electrically inductive element is electrically connected in series with the second electrically resistive element.

[0212] Example 8 - The surgical stapler of Example 6, wherein the second electrically inductive element is electrically connected in parallel with the second electrically resistive element.

[0213] Example 9 - The surgical stapler of Examples 6 or 8, further comprising a second electrically capacitive element electrically connected in series with the second electrically inductive element.

[0214] Example 10 - A surgical stapler is provided. The surgical stapler comprises a drive system, an electric motor mechanically coupled to the drive system, a battery electrically couplable to the electric motor, and a control system electrically connected to the electric motor. The control system comprises an H-bridge circuit, an electrically inductive element, and a filter magnetically coupled to the electrically inductive element. The H-bridge circuit comprises a high side and a low side, wherein the low side of the H-bridge circuit comprises first and second switching devices. The electrically inductive element is electrically connected in series with the first switching device. The control system is configured to control a force applied to the drive system based on a current in the filter.

[0215] Example 11 - The surgical stapler of Example 10, wherein the filter comprises a second electrically inductive element magnetically coupled to the first electrically inductive element, an electrically resistive element electrically connected to the second electrically inductive element, and an electrically capacitive element electrically connected to the electrically resistive element.

[0216] Example 12 - The surgical stapler of Examples 10 or 11, further comprising a sensor configured to sense the current in the filter.

[0217] Example 13 - The surgical stapler of Examples 10, 11 or 12, further comprising a third electrically inductive element electrically connected in series with the second switching device, and a second filter magnetically coupled to the third electrically inductive element, wherein the control system is further configured to control a second force applied to the drive system based on a second current in the second filter.

[0218] Example 14 - The surgical stapler of Example 13, wherein the second filter comprises a fourth electrically inductive element magnetically coupled to the third electrically inductive element, a second electrically resistive element electrically connected to the fourth electrically inductive element, and a second electrically capacitive element electrically connected to the second electrically resistive element.

[0219] Example 15 - The surgical stapler of Examples 12 or 13, further comprising a second sensor configured to sense the second current in the filter.

[0220] Example 16 - A surgical stapler is provided. The surgical stapler comprises a drive system, an electric motor mechanically coupled to the drive system, a battery electrically couplable to the electric motor, and a control system electrically connected to the electric motor. The control system comprises a pulse width modulation circuit and is configured to control a force applied to the drive system based on, one, a plurality of battery current measurements taken while a pulse signal generated by the pulse modulation circuit is above a baseline value, and, two, a plurality of predicted recirculating current values, wherein the predicted recirculating current values are based on at least one of the plurality of battery current measurements.

[0221] Example 17 - The surgical stapler of Example 16, wherein the control system is further configured to fit the plurality of battery current measurements to a first curve defined by a first mathematical equation, utilize a parameter of the first mathematical equation to predict a plurality of recirculating current values, fit the plurality of predicted recirculating current values to a second curve defined by a second mathematical equation, determine an intersection of the first and second curves, and determine a total area under the first and second curves.

[0222] Example 18 - The surgical stapler of Example 17, wherein the total area under the first and second curves is representative of an average current at the electric motor.

[0223] Example 19 - The surgical stapler of Examples 16, 17 or 18, wherein the control system is further configured to predict the recirculating current values based on a maximum value of the plurality of battery current measurements taken.

[0224] Example 20 - The surgical stapler of claim 19, wherein the control system is further configured to determine the maximum value, designate the maximum value as an ending condition of a battery current curve and as an initial condition of a recirculation current curve, generate the battery current curve based on a first mathematical equation and generate recirculation current curve based on a second mathematical equation, and determine a total area under the battery current curve and the recirculation current curve.

[0225] Example 21 The surgical stapler of Example 20, wherein the total area under the battery current curve and the recirculation current curve is representative of an average current at the electric motor.

[0226] Example 22 - A surgical stapler is provided. The surgical stapler comprises a drive system, an electric motor mechanically coupled to the drive system, a battery electrically couplable to the electric motor, and a control system electrically connected to the electric motor. The control system comprises a pulse width modulation circuit and is configured to control a force applied to the drive system based on, one, a battery current measurement taken while a pulse signal generated by the pulse modulation circuit is above a baseline value, and, two, a state of a duty cycle associated with the pulse width modulation circuit.

[0227] Example 23 - The surgical stapler of Example 22, wherein the control system is further configured to read a force value from a look-up table of a memory of the surgical stapler based on the measured battery current and the state of the duty cycle, compare the read force value to a target force value, and modify the duty cycle.

[0228] The entire disclosures of:

U.S. Patent No. 5,403,312, entitled ELECTRO SURGICAL HEMOSTATIC DEVICE, which issued on April 4, 1995; U.S. Patent No. 7,000,818, entitled SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS, which issued on February 21, 2006;

U.S. Patent No. 7,422, 139, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH TACTILE POSITION FEEDBACK, which issued on September 9, 2008;

U.S. Patent No. 7,464,849, entitled ELECTRO-MECHANICAL SURGICAL

INSTRUMENT WITH CLOSURE SYSTEM AND ANVIL ALIGNMENT COMPONENTS, which issued on December 16, 2008;

U.S. Patent No. 7,670,334, entitled SURGICAL INSTRUMENT HAVING AN

ARTICULATING END EFFECTOR, which issued on March 2, 2010;

U.S. Patent No. 7,753,245, entitled SURGICAL STAPLING INSTRUMENTS, which issued on July 13, 2010;

U.S. Patent No. 8,393,514, entitled SELECTIVELY ORIENT ABLE IMPLANTABLE FASTENER CARTRIDGE, which issued on March 12, 2013;

U.S. Patent Application Serial No. 11/343,803, entitled SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES; now U.S. Patent No. 7,845,537;

U.S. Patent Application Serial No. 12/031,573, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT HAVING RF ELECTRODES, filed February 14, 2008;

U.S. Patent Application Serial No. 12/031,873, entitled END EFFECTORS FOR A

SURGICAL CUTTING AND STAPLING INSTRUMENT, filed February 15, 2008, now U.S. Patent No. 7,980,443;

U.S. Patent Application Serial No. 12/235,782, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT, now U.S. Patent No. 8,210,411;

U.S. Patent Application Serial No. 12/249,117, entitled POWERED SURGICAL CUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM, now U.S. Patent No. 8,608,045;

U.S. Patent Application Serial No. 12/647,100, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT WITH ELECTRIC ACTUATOR DIRECTIONAL CONTROL ASSEMBLY, filed December 24, 2009; now U.S. Patent No. 8,220,688;

U.S. Patent Application Serial No. 12/893,461, entitled STAPLE CARTRIDGE, filed September 29, 2012, now U.S. Patent No. 8,733,613; U.S. Patent Application Serial No. 13/036,647, entitled SURGICAL STAPLING INSTRUMENT, filed February 28, 2011, now U.S. Patent No. 8,561,870;

U.S. Patent Application Serial No. 13/118,241, entitled SURGICAL STAPLING

INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Patent No. 9,072,535;

U.S. Patent Application Serial No. 13/524,049, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, filed on June 15, 2012; now U.S. Patent No. 9, 101,358;

U.S. Patent Application Serial No. 13/800,025, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on March 13, 2013, now U.S. Patent Application

Publication No. 2014/0263551;

U.S. Patent Application Serial No. 13/800,067, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on March 13, 2013, now U.S. Patent Application

Publication No. 2014/0263552;

U.S. Patent Application Publication No. 2007/0175955, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT WITH CLOSURE TRIGGER LOCKING MECHANISM, filed January 31, 2006; and

U.S. Patent Application Publication No. 2010/0264194, entitled SURGICAL STAPLING INSTRUMENT WITH AN ARTICULATABLE END EFFECTOR, filed April 22, 2010, now U.S. Patent No. 8,308,040, are hereby incorporated by reference herein.

[0229] 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.

[0230] 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.

[0231] By way of example only, aspects described herein may be processed before surgery. First, a new or used instrument may be obtained and when necessary cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK (commercially available from E. I. du Pont de Nemours and Company) bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation may kill bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a medical facility. A device also may be sterilized using any other technique known in the art, including but not limited to beta or gamma radiation, ethylene oxide, plasma peroxide, or steam.

[0232] 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.

[0233] 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.