Patent Publication Number: US-11653915-B2

Title: Surgical instruments with sled location detection and adjustment features

Description:
BACKGROUND 
     The present invention relates to surgical instruments and, in various arrangements, to surgical stapling and cutting instruments and staple cartridges for use therewith that are designed to staple and cut tissue. 
     SUMMARY 
     In one aspect, the present disclosure provides a surgical stapling instrument for use with a staple cartridge including a sled and staples. The surgical stapling instrument comprises a firing system. The firing system comprising a motor and a driving member operably coupled to the motor. The motor is configured to cause the driving member to advance the sled to deploy the staples into tissue grasped by the surgical stapling instrument. The driving member is movable by the motor along a predefined firing path. The surgical stapling instrument further comprises a control circuit that is configured to detect a location of the sled along the firing path, and adjust a motor control program based on the location of the sled. 
     In another aspect, the present disclosure provides a loading unit for use with a surgical stapling instrument. The loading unit comprises a shaft and an end effector extending from the shaft. The end effector comprises a first jaw that comprises an anvil. The end effector further comprises a second jaw. At least one of the first jaw and the second jaw is movable relative to the other to grasp tissue. The second jaw comprises an elongated channel comprising channel electrical contacts spaced apart along a length of the elongated channel defining a firing path. The second jaw further comprises a staple cartridge insertable into the elongated channel for assembly therewith. The staple cartridge comprises a cartridge pan, and a sled translatable along the firing path through positions defined by the channel electrical contacts. The loading unit further comprises a sled detection circuit transitionable from an open configuration to a closed configuration when the sled is moved into the positions. 
     In another aspect, the present disclosure provides a loading unit for use with a surgical stapling instrument. The loading unit comprises a shaft and an end effector extending from the shaft. The end effector comprises a first jaw that comprises an anvil. The end effector further comprises a second jaw. At least one of the first jaw and the second jaw is movable relative to the other to grasp tissue. The second jaw comprises an elongated channel and a staple cartridge insertable into the elongated channel for assembly therewith. The staple cartridge comprises a cartridge pan and a sled translatable relative to the cartridge pan from a home position along a firing path in a firing motion to deploy staples from the staple cartridge. The loading unit further comprises a sled position-resetting mechanism configured to return the sled to the home position from a predefined range of positions distal to the home positions prior to the firing motion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG.  1    is a perspective view of a surgical instrument, in accordance with at least one aspect of the present disclosure. 
         FIG.  2    is a perspective view of a motor operable, inner core, in accordance with at least one aspect of the present disclosure. 
         FIG.  3    is a perspective view of an embodiment of a housing in an open configuration and the inner core shown in  FIG.  2   . 
         FIG.  4    is a perspective view of the housing of  FIG.  3    having a different color associated therewith and being in a closed configuration, and the inner core shown in  FIG.  2   . 
         FIG.  5    is an exploded assembly view of a non-articulatable loading unit, in accordance with at least one aspect of the present disclosure. 
         FIG.  6    is an exploded assembly view of an articulatable loading unit, in accordance with at least one aspect of the present disclosure. 
         FIG.  7    is a cross-sectional view of a loading unit, in accordance with at least one aspect of the present disclosure. 
         FIG.  8    is an expanded view of a portion of the loading unit of  FIG.  7   . 
         FIG.  9    is a partial cross-sectional side view of the distal end of a drive assembly showing a latch member of a firing lockout assembly in a first or unlocked configuration. 
         FIG.  10    is a partial cross-sectional side view of the distal end of the drive assembly of  FIG.  9    showing the latch member in a second or locked configuration. 
         FIG.  11    is a partial exploded view of a staple cartridge assembly of a load unit, in accordance with at least one aspect of the present disclosure. 
         FIG.  12    is a partial cross-sectional view of the loading unit of  FIG.  11   . 
         FIG.  13    is a partial cross-sectional view of the staple cartridge assembly of  FIG.  11   . 
         FIG.  14    is a partial exploded view of a staple cartridge, in accordance with at least one aspect of the present disclosure. 
         FIG.  15    is a partial cross-sectional view of the staple cartridge of  FIG.  14   . 
         FIG.  16    is a partial perspective view of a staple cartridge, in accordance with at least one aspect of the present disclosure. 
         FIG.  17    is a partial exploded view of a staple cartridge, in accordance with at least one aspect of the present disclosure. 
         FIG.  18    is a partial cross-sectional view of the staple cartridge of  FIG.  17   . 
         FIG.  19    is a partial exploded view of a staple cartridge assembly, in accordance with at least one aspect of the present disclosure. 
         FIG.  20    is a top view and a cross-sectional view of a staple cartridge, in accordance with at least one aspect of the present disclosure. 
         FIG.  21    is a cross-sectional view of a staple cartridge assembly including the staple cartridge of  FIG.  20   . 
         FIG.  22    is a partial cross-sectional view of a staple cartridge including a sled and a retaining feature, in accordance with at least one aspect of the present disclosure. 
         FIG.  23    is a partial upside down perspective view of the staple cartridge of  FIG.  22   . 
         FIG.  24    illustrates a method of assembling the sled of the staple cartridge of  FIG.  22    with the retaining feature. 
         FIG.  25    partially illustrates a staple cartridge assembly including a staple cartridge and an elongated channel, and a drive member of a loading unit, in accordance with at least one aspect of the present disclosure. 
         FIG.  26    partially illustrates the staple cartridge assembly of  FIG.  25   , wherein the staple cartridge is properly seated in the elongated channel. 
         FIG.  27    is a partial transverse cross-sectional view of the staple cartridge assembly of  FIG.  25   . 
         FIG.  28    is a partial transverse cross-sectional view of the staple cartridge assembly of  FIG.  26   . 
         FIG.  29    is a partial perspective of a staple cartridge, in accordance with at least one aspect of the present disclosure. 
         FIG.  30    is a partial cross-sectional view of the staple cartridge of  FIG.  29   . 
         FIG.  31    is a logic flow diagram of a process depicting a control program or a logic configuration, in accordance with at least one aspect of the present disclosure. 
         FIG.  32    is a diagram of a surgical stapling instrument including a firing system, in accordance with at least one aspect of the present disclosure. 
         FIG.  33    illustrates a drive member of the surgical stapling instrument of  FIG.  32    at three positions along a firing path thereof, and a sled advanceable by the drive member to deploy staples of the surgical stapling instrument of  FIG.  32   . 
         FIG.  34    illustrates the drive member  FIG.  32    at two positions along the firing path. 
         FIG.  35    is a graph depicting, on the x-axis, the distance (δ) traveled by the drive member along the firing path from a starting position, and on the y-axis, the firing speed (V) and corresponding electrical load of the motor during a firing stroke of the powered surgical stapling instrument, in accordance with at least one aspect of the present disclosure. 
         FIG.  36    illustrates a staple cartridge including a retaining feature for maintaining a sled within the staple cartridge at a home position, in accordance with at least one aspect of the present disclosure. 
         FIG.  37    illustrates the staple cartridge of  FIG.  36    where the sled is advanced distally within the staple cartridge beyond the home position. 
         FIG.  38    illustrates the retaining feature of the staple cartridge of  FIG.  36   . 
         FIG.  39    illustrates a partial exploded view of a surgical stapling assembly, in accordance with at least one aspect of the present disclosure. 
         FIG.  40    is a graph illustrating varying resistances, on the y-axis, of a sled detection circuit and corresponding travel distances, on the x-axis, of a sled of the surgical stapling assembly of  FIG.  39   . 
         FIG.  41    is a partial cross-sectional view of the staple cartridge including a sled reset circuit, in accordance with at least one aspect of the present disclosure. 
         FIGS.  42 - 44    illustrate three positions of a sled over staple cartridge with respect to a retaining feature, in accordance with at least one aspect of the present disclosure. 
         FIG.  45    illustrates a partial perspective view of a staple cartridge including a sled retaining feature, in accordance with at least one aspect of the present disclosure. 
         FIG.  46    illustrates the staple cartridge of  FIG.  45    with a removed cartridge pan to expose the sled retaining feature. 
         FIG.  47    illustrates a simplified partial cross-sectional view of a staple cartridge assembly with a sled at a home position and at a position different than the home position, in accordance with at least one aspect of the present disclosure. 
         FIG.  48    illustrates a simplified partial cross-sectional view of the staple cartridge assembly of  FIG.  47    with a working end of a drive member being advanced to engage a raised portion of a sled resetting member, in accordance with at least one aspect of the present disclosure. 
         FIG.  49    illustrates a handle of a surgical instrument including a firing trigger movable to a first position and a second position, in accordance with at least one aspect of the present disclosure. 
         FIG.  50    illustrates a motor assembly operably coupled to a sled resetting member, in accordance with at least one aspect of the present disclosure. 
         FIG.  51    illustrates a handle of a surgical instrument including a firing trigger and a sled resetting actuator, in accordance with at least one aspect of the present disclosure. 
         FIG.  52    illustrates a partial exploded view of a loading unit including an anvil and a surgical stapling assembly including a staple cartridge for assembly with an elongated channel, in accordance with at least one aspect of the present disclosure. 
         FIG.  53    illustrates a partial cross-sectional view of the loading unit of  FIG.  52   , showing a staple cartridge assembled with an elongated channel in an unlocked configuration and an anvil in an open configuration with the elongated channel 
         FIG.  54    illustrates a partial cross-sectional view of the loading unit of  FIGS.  52  and  53    showing the staple cartridge and the elongated channel in a locked configuration and the anvil in a closed configuration with the elongated channel. 
         FIG.  55    illustrates a partial perspective view of the surgical stapling assembly of  FIG.  52    in the locked configuration. 
         FIG.  56    illustrates a partial perspective view of the surgical stapling assembly of  FIG.  52    being transitioned into from the locked configuration to the unlocked configuration. 
         FIG.  57    illustrates a partial perspective view of a surgical stapling assembly including a retainer, a staple cartridge, and an elongated channel, in accordance with at least one aspect of the present disclosure. 
         FIGS.  58 - 61    illustrate a method of utilizing the retainer of  FIG.  57    to release the staple cartridge from the elongated channel. 
         FIG.  62    illustrates a partial cross-sectional view of a staple cartridge assembly, in accordance with at least one aspect of the present disclosure. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate certain 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 
     Applicant of the present application also owns the following U.S. Patent Applications that were filed on Dec. 2, 2020 and which are each herein incorporated by reference in their respective entireties:
     U.S. patent application Ser. No. 17/109,589, entitled METHOD FOR TISSUE TREATMENT BY SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2022/0168038;   U.S. patent application Ser. No. 17/109,595, entitled SURGICAL INSTRUMENTS WITH INTERACTIVE FEATURES TO REMEDY INCIDENTAL SLED MOVEMENTS, now U.S. Patent Application Publication No. 2022/0167980;   U.S. patent application Ser. No. 17/109,615, entitled SURGICAL INSTRUMENT WITH CARTRIDGE RELEASE MECHANISMS, now U.S. Patent Application Publication No. 2022/0167972;   U.S. patent application Ser. No. 17/109,627, entitled DUAL-SIDED REINFORCED RELOAD FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2022/0167981;   U.S. patent application Ser. No. 17/109,636, entitled SURGICAL SYSTEMS WITH DETACHABLE SHAFT RELOAD DETECTION, now U.S. Patent Application Publication No. 2022/0167973;   U.S. patent application Ser. No. 17/109,645, entitled SURGICAL INSTRUMENTS WITH ELECTRICAL CONNECTORS FOR POWER TRANSMISSION ACROSS STERILE BARRIER, now U.S. Patent Application Publication No. 2022/0167982;   U.S. patent application Ser. No. 17/109,648, entitled DEVICES AND METHODS OF MANAGING ENERGY DISSIPATED WITHIN STERILE BARRIERS OF SURGICAL INSTRUMENT HOUSINGS, now U.S. Patent Application Publication No. 2022/0167983;   U.S. patent application Ser. No. 17/109,651, entitled POWERED SURGICAL INSTRUMENTS WITH EXTERNAL CONNECTORS, now U.S. Patent Application Publication No. 2022/0167977;   U.S. patent application Ser. No. 17/109,656, entitled POWERED SURGICAL INSTRUMENTS WITH SMART RELOAD WITH SEPARATELY ATTACHABLE EXTERIORLY MOUNTED WIRING CONNECTIONS, now U.S. Patent Application Publication No. 2022/0167974;   U.S. patent application Ser. No. 17/109,667, entitled POWERED SURGICAL INSTRUMENTS WITH COMMUNICATION INTERFACES THROUGH STERILE BARRIER, now U.S. Patent Application Publication No. 2022/0167984; and   U.S. patent application Ser. No. 17/109,669, entitled POWERED SURGICAL INSTRUMENTS WITH MULTI-PHASE TISSUE TREATMENT, now U.S. Patent Application Publication No. 2022/0167975.   

     Applicant of the present application owns the following U.S. Patent Applications, filed on Dec. 4, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:
     U.S. patent application Ser. No. 16/209,385, entitled METHOD OF HUB COMMUNICATION, PROCESSING, STORAGE AND DISPLAY;   U.S. patent application Ser. No. 16/209,395, entitled METHOD OF HUB COMMUNICATION;   U.S. patent application Ser. No. 16/209,403, entitled METHOD OF CLOUD BASED DATA ANALYTICS FOR USE WITH THE HUB;   U.S. patent application Ser. No. 16/209,407, entitled METHOD OF ROBOTIC HUB COMMUNICATION, DETECTION, AND CONTROL;   U.S. patent application Ser. No. 16/209,416, entitled METHOD OF HUB COMMUNICATION, PROCESSING, DISPLAY, AND CLOUD ANALYTICS;   U.S. patent application Ser. No. 16/209,423, entitled METHOD OF COMPRESSING TISSUE WITHIN A STAPLING DEVICE AND SIMULTANEOUSLY DISPLAYING THE LOCATION OF THE TISSUE WITHIN THE JAWS;   U.S. patent application Ser. No. 16/209,427, entitled METHOD OF USING REINFORCED FLEXIBLE CIRCUITS WITH MULTIPLE SENSORS TO OPTIMIZE PERFORMANCE OF RADIO FREQUENCY DEVICES;   U.S. patent application Ser. No. 16/209,433, entitled METHOD OF SENSING PARTICULATE FROM SMOKE EVACUATED FROM A PATIENT, ADJUSTING THE PUMP SPEED BASED ON THE SENSED INFORMATION, AND COMMUNICATING THE FUNCTIONAL PARAMETERS OF THE SYSTEM TO THE HUB;   U.S. patent application Ser. No. 16/209,447, entitled METHOD FOR SMOKE EVACUATION FOR SURGICAL HUB;   U.S. patent application Ser. No. 16/209,453, entitled METHOD FOR CONTROLLING SMART ENERGY DEVICES;   U.S. patent application Ser. No. 16/209,458, entitled METHOD FOR SMART ENERGY DEVICE INFRASTRUCTURE;   U.S. patent application Ser. No. 16/209,465, entitled METHOD FOR ADAPTIVE CONTROL SCHEMES FOR SURGICAL NETWORK CONTROL AND INTERACTION;   U.S. patent application Ser. No. 16/209,478, entitled METHOD FOR SITUATIONAL AWARENESS FOR SURGICAL NETWORK OR SURGICAL NETWORK CONNECTED DEVICE CAPABLE OF ADJUSTING FUNCTION BASED ON A SENSED SITUATION OR USAGE;   U.S. patent application Ser. No. 16/209,490, entitled METHOD FOR FACILITY DATA COLLECTION AND INTERPRETATION; and   U.S. patent application Ser. No. 16/209,491, entitled METHOD FOR CIRCULAR STAPLER CONTROL ALGORITHM ADJUSTMENT BASED ON SITUATIONAL AWARENESS.   

     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. 
     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&#39;s body or can be inserted through an access device that has a working channel through which the end effector and elongate shaft of a surgical instrument can be advanced. 
     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 the 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. 
     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. 
     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. 
     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. 
     With reference to  FIGS.  1 - 4   , a surgical instrument system is provided, such as, for example, an electromechanical surgical instrument system  10 . System  10  includes a handle assembly  100 , a plurality of types of adapter or shaft assemblies such as, for example, adapter assembly  200   a , and a plurality of types of end effectors such as, for example, end effector  300   a . Handle assembly  100  is configured for selective attachment thereto with any one of a number of adapter assemblies, for example, adapter assembly  200   a , and, in turn, each unique adapter assembly  200   a  is configured for selective connection with any number of surgical loading units or end effectors, such as, for example, end effector  300   a . End effector  300   a  and adapter assembly  200   a  are configured for actuation and manipulation by handle assembly  100 . Upon connecting one adapter assembly  200   a , for example, to handle assembly  100  and one type of end effector such as, for example, end effector  300   a  to the selected adapter assembly  200   a , a powered, hand-held, electromechanical surgical instrument is formed. 
     For a detailed description of the construction and operation of an exemplary electromechanical, hand-held, powered surgical instrument, reference may be made to International Publication No. WO 2009/039506 and U.S. Patent Application Publication No. 2011/0121049, the entire contents of all of which are incorporated herein by reference. 
     With reference to  FIGS.  1  and  2   , handle assembly  100  includes an inner core  101  and a housing or shell  110   a  configured to selectively receive and encase inner core  101 . Inner core  101  is motor operable and configured to drive an operation of a plurality of types of end effectors. Inner core  101  has a plurality of sets of operating parameters (e.g., speed of operation of motors of inner core  101 , an amount of power to be delivered by motors of inner core  101  to an adapter assembly, selection of motors of inner core  101  to be actuated, functions of an end effector to be performed by inner core  101 , or the like). Each set of operating parameters of inner core  101  is designed to drive the actuation of a specific set of functions unique to respective types of end effectors when an end effector is coupled to inner core  101 . For example, inner core  101  may vary its power output, deactivate or activate certain buttons thereof, and/or actuate different motors thereof depending on the type of end effector that is coupled to inner core  101 . 
     With specific reference to  FIG.  2   , inner core  101  defines an inner housing cavity therein in which a power-pack  106  is situated. Power-pack  106  is configured to control the various operations of inner core  101 . Power-pack  106  includes a plurality of motors  108   a ,  108   b  operatively engaged thereto. The rotation of motors  108   a ,  108   b  function to drive shafts and/or gear components of adapter assembly  200   a , for example, in order to drive the various operations of end effectors attached thereto, for example, end effector  300   a . Although two motors are depicted in the example illustrated in  FIG.  2   , in other examples, a handle assembly can include more or less than two motors. 
     In various examples, the handle assembly  100  is replaced with a robotic arm of a robotic system. In such examples, the adapter assembly  200   a  may also be effectively employed with a tool drive assembly of a robotically controlled or automated surgical system. For example, the adapter assemblies disclosed herein may be employed with various robotic systems, instruments, components, and methods such as, but not limited to, those disclosed in U.S. Pat. No. 9,072,535, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, which is hereby incorporated by reference herein in its entirety. 
     When end effector  300   a  is coupled to inner core  101 , motors of power-pack  106  are configured to drive shafts and/or gear components of adapter assembly  200   a  in order to selectively move end effector  300   a  relative to a proximal body portion  302   a  of end effector  300   a , to rotate end effector  300   a  about a longitudinal axis “X”, to move a cartridge assembly  308   a  and an anvil assembly  306   a  of end effector  300   a  relative to one another, and/or to fire staples from within cartridge assembly  308   a  of end effector  300   a.    
     With reference to  FIGS.  3  and  4   , surgical instrument system  10  further includes a disposable outer housing  110 . The housing  110  is configured to encase inner core  101  thereby inhibiting surgical debris from penetrating and contaminating inner core  101  during a surgical procedure. The housing  110  selectively encases inner core  101  prior to use and may then be detached from inner core  101  following use in order to be disposed of, or, in some instances, sterilized for re-use. 
     With reference to  FIG.  3   , the housing  110  includes a housing portion  112   a . The housing  110  further includes a housing portion  112   b  movably coupled to the housing portion  112   b  by a hinge  120   a  located along an upper edge of housing portion  112   b . Housing portions  112   a ,  112   b  are pivotable relative to one another between a closed, fully coupled configuration, as shown in  FIG.  4   , and an open, partially detached configuration, as shown in  FIG.  3   . When joined, housing portions  112   a ,  112   b  define a cavity  122   a  therein in which inner core  101 , memory  114 , and a microprocessor  140  may be selectively situated. In certain instances, the housing portions  112   a    112   b  may be fabricated from any suitable material, such as, for example, a polycarbonate. In certain instances, the memory  114  and the microprocessor  140  are incorporated into the inner core  101 , for example. 
     It is contemplated that the memory  114  may be non-volatile memories, such as, for example, electrically erasable programmable read-only memories. Memory  114  have stored therein discrete operating parameters of inner core  101  that correspond to the operation of one type of end effector, for example, end effectors such as, for example end effector  300   a  and/or one type of adapter assembly such as, for example, adapter assembly  200   a . The operating parameter(s) stored in memory  114  can be at least one of: a speed of operation of motors  108   a ,  108   b  of inner core  101 ; an amount of power to be delivered by motors  108   a ,  108   b  of inner core  101  during operation thereof; which motors  108   a ,  108   b  of inner core  101  are to be actuated upon operating inner core  101 ; types of functions of end effectors to be performed by inner core  101 ; or the like. 
       FIG.  5    depicts an example of a loading unit  16  that may be used in connection with the surgical instrument system  10  in a manner discussed in U.S. Pat. No. 5,865,361, the disclosure of which is herein incorporated by reference in its entirety. 
     As can be seen in  FIG.  5   , the loading unit  16  may generally comprise a tool assembly  17  for performing surgical procedures such as cutting tissue and applying staples on each side of the cut. In particular, the tool assembly includes a cartridge assembly  18  that houses a plurality of surgical staples therein. The tool assembly  17  also includes a staple-forming anvil assembly  20  that has an anvil portion  204  that has a plurality of staple deforming concavities formed in the undersurface thereof. A cover plate  208  is commonly secured to a top surface of anvil portion  204  to define an anvil cavity therebetween. The anvil cavity is dimensioned to receive a distal end of an axial drive assembly  212 . A longitudinal slot  214  extends through anvil portion  204  to facilitate passage of retention flange  284  of axial drive assembly  212  into the anvil cavity. A camming surface  209  is formed on a proximal end of anvil portion  204  and is positioned to engage axial drive assembly  212  to facilitate closing of the anvil assembly  20 . 
     Cartridge assembly  18  generally includes a carrier  216  which defines an elongated support channel  218 . Elongated support channel  218  is dimensioned and configured to receive a staple cartridge  220  therein. Such staple cartridge  220  supports a plurality of fasteners and pushers as is known in the art. A plurality of spaced-apart longitudinal slots  230  extend through staple cartridge  220  to accommodate upstanding cam wedges  232  of an actuation sled  234 . A central longitudinal slot  282  extends along the length of staple cartridge  220  to facilitate passage of a knife blade  280  formed on the axial drive assembly  212 . During operation of the loading unit  16 , actuation sled  234  translates through longitudinal slots  230  of staple cartridge  220  to advance cam wedges  232  into sequential contact with the pushers that are operably supported in the cartridge  220  to cause the pushers to translate vertically within the cartridge  220  and urge the fasteners (staples) associated with the pushers into the staple deforming cavities of the anvil assembly  20 . A pair of pivot members  211  are formed on the proximal end of the anvil portion  204  and are configured to be received in slots  213  that are formed in carrier  216  to enable the anvil portion  204  to pivot between the open and tissue-clamping positions. 
     As can also be seen in  FIG.  5   , the loading unit  16  also has a housing portion  200  that is adapted to snap onto or otherwise be attached to the carrier  216 . The axial drive assembly  212  includes an elongated drive beam  266  that has a distal working head  268  and a proximal engagement section  270 . As is known, the drive beam  266  may be constructed from a single sheet of material or, preferably, from multiple stacked sheets. Engagement section  270  includes a pair of engagement fingers  270   a  and  270   b  that are dimensioned and configured to mountingly engage a pair of corresponding retention slots  272   a  formed in a drive member  272 . Drive member  272  may include a proximal aperture that is configured to receive the distal end of a control rod as discussed in U.S. Pat. No. 5,865,361. 
     The distal end of drive beam  266  includes a vertical support strut  278  which supports the knife blade  280 , and an abutment surface  283  which engages the central portion of actuation sled  234  during a stapling procedure. Surface  285  is located at the base of surface  283  and is configured to receive a support member  287  that is slidably positioned along the bottom of the carrier  216 . Knife blade  280  is generally positioned to translate slightly behind actuation sled  234  through a central longitudinal slot  282  in staple cartridge  220  to form an incision between rows of stapled body tissue. 
     A retention flange  284  projects distally from vertical strut  278  and supports a camming pin  286  at its distal end. Camming pin  286  is dimensioned and configured to engage camming surface  209  on anvil portion  204  to clamp anvil portion  204  against body tissue. In addition, a leaf spring  207  may be provided between the proximal end of the anvil portion  204  and the distal end portion of the housing  200  to bias the anvil assembly  20  to a normally open position. The loading unit  16  may further include a lockout device  288  and spring  304  arrangement as described in U.S. Pat. No. 5,865,361. 
       FIG.  6    illustrates an articulatable loading unit  16 ′ that includes a tool assembly  17  that has an anvil assembly  20  and cartridge assembly  18 . Anvil assembly  20  includes an anvil portion  204  that has a plurality of staple deforming concavities formed in the undersurface thereof. A cover plate  208  is secured to a top surface of anvil portion  204  to define an anvil cavity therebetween. The anvil cavity is dimensioned to receive a distal end of an axial drive assembly  212 . A longitudinal slot  214  extends through anvil portion  204  to facilitate passage of retention flange  284  of axial drive assembly  212  into the anvil cavity. A camming surface  209  formed on anvil portion  204  may be positioned to engage axial drive assembly  212  to facilitate clamping of tissue between the anvil assembly  20  and the cartridge assembly  18 . 
     The cartridge assembly  18  includes a carrier  216  that supports a staple cartridge  220  therein. Staple cartridge  220  includes retention slots  225  for receiving a plurality of fasteners (staples) and pushers. A plurality of spaced apart longitudinal slots  230  extend through staple cartridge  220  to accommodate upstanding cam wedges  232  of an actuation sled  234 . A central longitudinal slot  282  extends along the length of staple cartridge  220  to facilitate passage of a knife blade  280 . During operation of the loading unit  16 ′, actuation sled  234  translates through longitudinal slots  230  of staple cartridge  220  to advance cam wedges  232  into sequential contact with the pushers that are operably supported in the cartridge  220  to cause the pushers to urge the fasteners into the staple deforming cavities of the anvil assembly  20 . A pair of pivot members  211  are formed on anvil portion  204  and are positioned within slots  213  formed in the carrier  216  to guide the anvil portion  204  between the open and tissue-clamping positions. 
     The articulatable loading unit  16 ′ further includes a housing portion  200  that comprises an upper housing half  250  and a lower housing half  252 . The proximal end of housing half  250  may include engagement nubs  254  for releasably engaging elongated body  14 . Nubs  254  form a bayonet type coupling with the distal end of body  14  as described in U.S. Pat. No. 5,865,361. As can also be seen in  FIG.  6   , the axial drive assembly  212  includes an elongated drive beam  266  that has a distal working head and a proximal engagement section  270 . Drive beam  266  may be constructed from a single sheet of material or, preferably, from multiple stacked sheets. Engagement section  270  includes a pair of engagement fingers  270   a  and  270   b  that are dimensioned and configured to mountingly engage a pair of corresponding retention slots  272  a formed in a drive member  272 . Drive member  272  includes a proximal port-aperture configured to receive the distal end of control rod when the proximal end of loading unit  16 ′ is engaged with elongated body  14  of a surgical stapling apparatus as disclosed in U.S. Pat. No. 5,865,361. 
     The distal end of drive beam  266  is defined by a vertical support strut  278  which supports a knife blade  280 , and an abutment surface  283  which engages the central portion of actuation sled  234  during a stapling procedure. Surface  285  at the base of surface  283  may be configured to receive a support member  287  that is slidably positioned along the bottom of the carrier  216 . Knife blade  280  is generally positioned to translate slightly behind actuation sled  234  through a central longitudinal slot  282  in staple cartridge  220  to form an incision between rows of stapled body tissue. To provide support to the drive beam  266  within the housing portion  200  as the drive beam  266  is advanced axially, a blade stabilizing member  290  is mounted within the housing portion  200 . A retention flange  284  projects distally from vertical strut  278  and supports a pair of cylindrical cam rollers  286  at its distal end. Cam rollers  286  are dimensioned and configured to engage camming surface  209  on anvil portion  204  to clamp anvil portion  204  against body tissue. 
     The articulatable reload unit  16 ′ includes an articulation joint  340  that includes a mounting assembly  202  that comprises an upper mounting portion  236  and a lower mounting portion  238 . A pivot pin  244  is formed on each of the mounting portions  236 ,  238  and serve to define a pivot axis “A 1 -A 1 ” which may be substantially perpendicular to the longitudinal axis “L-L” of the articulatable loading unit  16 ′. The mounting assembly  202  is pivotally coupled to the distal end of the housing portion  200  by a pair of coupling members  246 . Each of coupling members  246  has an aperture  247  therethrough for receiving a corresponding pin  244  therethrough. The proximal end  248  of each coupling member  246  is configured to be interlockingly received in a corresponding groove  251  formed in the distal end of the upper housing half  250  and the distal end of the lower housing half  252 . A pair of springs  207  are provided between the proximal end of the anvil portion  204  and the upper mounting portion  236  to bias the anvil assembly  20  to a normally open position. An articulation link  256  may be provided to articulate the tool assembly  17  about the articulation axis “A 1 -A 1 ” relative to the housing portion  200  as is taught in U.S. Pat. No. 5,865,361. 
       FIGS.  7  and  8    illustrate an example of a loading unit  1100  for use with the surgical instrument system  10 . The loading unit  1100  is substantially as described in U.S. Patent Application Publication No. 2013/0098965 and U.S. Patent Application Publication No. 2016/0249921, which are incorporated by reference herein in their entireties. The loading unit  1100  includes a proximal body portion  1102  and a tool assembly  1104 . 
     The loading unit  1100  further includes a drive assembly  1180  that includes a drive member  1182  having a body and a working end  1184 . The working end  1184  includes an upper flange  1186   a , a lower flange  1186   b , a vertical strut interconnecting the upper flange  1186   a  and the lower flange  1186   b , and a knife  1187  supported on or formed into the vertical strut. The upper flange  1186   a  is positioned to be slidably received within the channel  1131  of the anvil assembly  1130  and the lower flange  1186   b  is positioned to be slidably positioned along an outer surface  1156   a  of the jaw member  1156 . In use, distal movement of the drive member  1182  initially advances the upper flange  1186   a  into a cam surface formed on the anvil plate  134  and advances the lower flange  1186   b  into engagement with a cam surface  1156   b  formed on the jaw member  1156  to pivot the cartridge assembly  1150  towards the anvil assembly  1130  to the approximated or closed position. Continued advancement of the drive member  1182  progressively maintains a minimum tissue gap between the anvil assembly  1130  and the cartridge assembly  1150  adjacent the working end  184  of the drive assembly  1180  as the working end  1184  moves through the tool assembly  1104 . 
     Actuation sled  1162  is disposed within cartridge assembly  1150  at a position distal of the working end  1184 . When the working end  1184  is in its proximal-most position and the tool assembly  1104  is in the open or unapproximated position, the sled  1162  and the working end  1184  are in their initial position. The sled  1162  includes a plurality of cam surfaces which are positioned to engage and lift the pushers within the staple retention slots the cartridge body of cartridge assembly  1150 . The pushers are positioned within the cartridge assembly  1150  to eject the staples from the cartridge body when the sled  1162  is advanced through the tool assembly  1104 . 
     Referring to  FIGS.  7 - 10   , the loading unit  1100  includes a firing lockout assembly  1221  that includes a latch member  1222  which is pivotally supported on a distal end of a lower mounting portion  1174 . The latch member  1222  includes a U-shaped body having a proximal base member  224  and two spaced distally extending legs. The base member  1224  is provided with a blocking member which defines a blocking surface and is welded or secured to the base member  1224  to provide additional support to the base member  1224 . Alternatively, the base member  1224  and the blocking member are integrally or monolithically formed. The latch member  1222  is pivotal from a first position ( FIG.  9   ) to a second position ( FIG.  10   ). In the first position shown in  FIG.  9   , the blocking member  1224   a  of the latch member  1222  is aligned with the stop surface  1184   a  of the drive member  1182  to prevent advancement of the drive member  1182  within the tool assembly  1104 . In the second position shown in  FIG.  10   , the blocking member  1224   a  is misaligned with the stop surface  1184   a  of the drive member  1182  to permit advancement of the drive member  1182  within the tool assembly  1104 . 
     Further to the above, insertion of an unfired cartridge assembly  1150  into an elongated channel  1157  of the jaw member  1156  pivots the latch member  1222  to the second position thereby permitting advancement of the drive member  1182  within the tool assembly  1104 . A proximal portion of the sled  1162  holds the latch member  1222  in the second position against the biasing force of a biasing member  1230 . During firing, when the sled  1162  is advanced distally through the cartridge assembly  1150 , the sled  1162  disengages from the latch member  1222 , and the biasing member  230  causes the latch member  1222  to return to the first position where the latch member  1222  re-enters a locking engagement with the drive member  182 . 
     Notably, an incidental bumping or shaking of the unfired cartridge assembly  1150  may cause a slight movement of the sled  1162  within the unfired cartridge assembly  1150 . Such movement can be problematic as a misaligned sled  1162  cannot deactivate the firing lockout assembly  1221  by causing the latch member  1222  to transition to the second position upon insertion of the unfired cartridge assembly  1150 . Consequently, advancement of the drive member  1182  remains hindered even though a new unfired cartridge assembly  1150  is ready for firing. 
     Further to the above, a properly installed unfired cartridge assembly  1150  can suffer the same fate due to incidental bumping or shaking of the loading unit  1100 . The slight movement of the sled  1162  may cause the latch member  1222  to be disengaged from the sled  1162 , thereby allowing the latch member  1222  to be returned to the first position by the biasing force of the biasing member  1230 . Consequently, the firing lockout assembly  1221  is prematurely reactivated by the incidental bumping or shaking of the loading unit  1100  before an actual firing commences. 
     In either event, the misalignment of the sled  1162  can be frustrating to a user expecting an apparently properly-installed unfired cartridge assembly  1150  to be fired to deploy staples into a tissue grasped between the anvil assembly  1130  and the cartridge assembly  1500 . When the firing inevitably fails, the user is left with no recourse but to release the tissue sacrificing all the time spent to identifying the most suitable tissue bite and aligning the loading unit  1100  therewith for grasping. Moreover, confident in that the cartridge assembly is new and unfired, the user may attempt to replace the loading unit  1100  and/or the surgical instrument system  10 , which is costly and will not be a successful remedy if the user installs the cartridge assembly  1150  was the misaligned sled  1162  into the new loading unit  1100 . 
     The present disclosure provides various solutions that maintain a sled  1162  in a proper position for an unfired cartridge assembly  1150 . Additionally, or alternatively, the present disclosure provides various mechanisms for detecting an incidental movement of the sled  1162  from its proper position. The present disclosure further provides various mechanisms actively returning the sled  1162  to its proper position. 
     Referring to  FIGS.  11 - 13   , a loading unit  1200  is similar in many respects to the loading unit  1100 . For example, the loading unit  1200  includes the proximal body portion  1102  ( FIG.  8   ) and a tool assembly  1204  that includes an end effector with a jaw  1236  including an anvil assembly  1230  and a jaw  1256  including a staple cartridge assembly  1250 . At least one of the jaws  1236 ,  1256  is movable relative to the other to grasp tissue between the anvil assembly  1230  and the staple cartridge assembly  1250 . 
     Furthermore, the staple cartridge assembly  1250  includes an elongated channel  1257  dimensioned and designed to receive and releasably retain a staple cartridge  1220  similar in many respects to other staple cartridges described elsewhere herein such as, for example, the staple cartridge  220 . Staples are deployed from the staple cartridge  1220  through a cartridge deck  1255  into the tissue via staple drivers motivated by the sled  1262  in a similar manner to that described in connection loading units  16 ,  16 ′,  1100  of  FIGS.  1 - 8   . The staples and the staple drivers are stored in a cartridge body  1259  of the staple cartridge  1220 . 
     A cartridge pan  1258  is attached to the bottom of the cartridge body  1259  to prevent the staple drivers from falling out of the cartridge body  1259 . The cartridge pan  1258  includes a pan slot  1254  that is aligned with a cartridge slot defined in the cartridge deck  1255 . The pan slot  1254  is also aligned with a channel slot  1253  defined in a base portion  1252  of the elongated channel  1257 . During firing, the working end  1184  of the drive member  1182  ( FIG.  9   ) slidably moves through the cartridge slot, the pan slot  1254 , and the channel slot  1253  distally advancing the sled  1262  from a first position toward a second position within the cartridge body to cause the staple drivers to deploy the staples through the cartridge deck  1255 . 
     Furthermore, the loading unit  1200  includes the firing lockout assembly  1221  configured to prevent advancement of the drive member  1182  in the absence of an unfired staple cartridge  1220  with a properly positioned sled  1262 . To resist a movement of the sled  1262  due to an incidental bumping or shaking of the staple cartridge  1220 , the base portion  1252  includes one or more retaining features (e.g., retaining features  1270   a ,  1270   b ) configured to matingly engage the sled  1262  and resist a movement of the sled  1262  up to a predetermined force. 
     In certain instances, as illustrated in  FIG.  13   , the sled  1262  includes one or more apertures, bores, grooves, or detents (e.g., detents  1272   a ,  1272   b ) defined in a sled base  1263 . The detents  1272   a ,  1272   b  are aligned with and configured to receive the retaining features  1270   a ,  1270   b  when the sled  1262  is located at the first position. In the example illustrated in  FIGS.  11 - 13   , the retaining features  1270   a ,  1270   b  extend through corresponding apertures or cutouts  1274   a ,  1274   b  in the cartridge pan  1258  when the staple cartridge  1220  is properly seated in the elongated channel  1257 . 
     In the illustrated example, when the sled  1262  is at the first position, the retaining feature  1270   a , the detent  1272   a , and the cutout  1274   a  reside on a first side of a plane longitudinally bisecting the staple cartridge  1220  and extending longitudinally along the cartridge slot, the pan slot  1254 , and the channel slot  1253 . The retaining feature  1270   b , the detent  1272   b , and the cutout  1274   b  reside on a second side of a plane opposite the first side. 
     In various examples, the retaining features  1270   a ,  1270   b  are in the form of bumps or protrusions extending upwardly from the base portion  1252 . The retaining features  1270   a ,  1270   b  may define ramps and/or curved profiles comprise with radii of curvatures dimensioned to resist advancement of the sled  1262  when a driving force applied by the drive member  1182  to the sled  1262  is less than or equal to a predetermined force. 
     In various aspects, a retaining feature may comprise a triangular prism shape, a partial ellipsoid shape, a partial spherical shape, a partial cylindrical shape, or a truncated pyramid shape. Other shapes are also contemplated by the present disclosure. In various aspects, a retaining feature height may be less than, or equal to, than a depth a corresponding detent of a sled to ensure that the sled is not lifted by the retaining feature when assembled therewith. In various aspects, the number of retaining features can be more or less than two. In one example, a single retaining feature can be employed with corresponding detent and cutout. In another example, three or more retaining features can be employed with corresponding detents and cutouts. In certain examples, dedicated cutouts are replaced with a single cutout that accommodates the passing of multiple retaining features therethrough. 
     When the driving force applied by the drive member  1182  exceeds the predetermined force, the sled  1262  moves out of alignment with the retaining features  1270   a ,  1270   b  toward the second position. After the sled  1262  reaches the second position, the drive member  1182  is retracted to a starting position where the firing lockout assembly  1221  is reactivated to prevent re-advancement of the drive member  1182  until an unfired staple cartridge  1220  is assembled with the elongated channel such that a sled  1262  is properly located at the first position. A proximal portion of the sled  1262  engages the latch member  1222  deactivating the firing lockout assembly  1221 . 
       FIG.  13    illustrates an example of a retaining feature  1270   a  of the unfired staple cartridge  1220  properly seated in the elongated channel  1257 . The detent  1272   a  of the sled  1262  of the unfired staple cartridge  1220  is properly aligned to receive the retaining feature  1270   a  through the cutout  1274   a  at a first position, which yields an unlocked configuration of the firing lockout assembly  1221 . The retaining feature  1270   a  includes a base portion  1277  protruding from the elongated channel  1257  and extending into the cutout  1274   a , and a head portion  1279  protruding from the based portion and extending into the detent  1272   a  of the sled  1262 . The head portion  1279 , but not the base portion  1277 , extend through the cutout  1274   a  beyond the cartridge pan  1258  and into the detent  1272   a.    
     The base portion  1277  ensures proper alignment of the staple cartridge  1220  with the elongated channel  1257 , and the head portion  1279  ensures that the sled  1262  remains at the first position until a driving force greater than a predetermined driving force is applied thereto. In the illustrated example, the base portion  1277  has a rectangular, or at least substantially rectangular, cross-section. In certain instances, the head portion  1279  has a curved profile that defines a ramp resists advancement of the sled  1262  at or below a predetermined force defined by a radius of curvature of the head portion  1279 . 
     Furthermore, the head portion  1277  is slightly smaller in size than the detent  1272   a  to permit slight movements of the sled relative to the head portion  1279  without an unintended transition in the firing lockout assembly from the unlocked configuration to the locked configuration. In the illustrated example, the detent  1272   a  has a length d 2  greater than a length d 1  of the head portion  1279  by a distance Δd (difference between d 1  and d 2 ). As such, the sled is slidably movable relative to the cartridge pan  1258  a distance Δd without compromising the mating engagement between the head portion  1279  and the detent  1272   a.    
       FIGS.  14  and  15    illustrate a staple cartridge  1220 ′ similar in many respects to the staple cartridges  220 ,  1220 . For example, the staple cartridge  1220 ′ includes the sled  1262  with the detents  1272   a . However, unlike the staple cartridge  1220 , a cartridge pan  1258 ′ of the staple cartridge  1220 ′ does not include cutouts to accommodate retaining features of an elongated channel. Instead, the cartridge pan  1258 ′ includes retaining features  1270   a ′ and  1270   b ′ protruding from the cartridge pan  1258 ′. The retaining features  1270   a ′ and  1270   b ′ are similar in many respects to the retaining features  1270   a ,  1270   b . For example, the retaining features  1270   a ′ and  1270   b ′ are configured to matingly engage the detents  1272   a ,  1272   b  of the sled  1262  to maintain the sled  1262  at the first position corresponding to an unlocked configuration of the firing lockout assembly  1221  ( FIG.  9   ). 
     In the example illustrated in  FIGS.  14  and  15   , the retaining features  1270   a ′,  1270   b ′ are on opposite sides of the pan slot  1254 . The retaining features  1270   a ′  1270   b ′ are defined in a base portion of the cartridge pan  1258 ′ adjacent side walls  1273   a ,  1273   b . In the illustrated examples, the retaining features  1270   a ′  1270   b ′ are aligned across the pan slot  1254 . In other examples, the retaining features  1270   a ′  1270   b ′ can be offset. 
       FIG.  16    illustrates an alternative staple cartridge  1220 ″ similar in many respects to other staple cartridges described elsewhere herein such as, for example, the staple cartridges  220 .  1220 .  1220 ′. Staples are deployed from the staple cartridge  1220 ″ through a cartridge deck into tissue via staple drivers motivated by a sled  1162  in a similar manner to that described in connection loading units  16 ,  16 ′,  1100  of  FIGS.  1 - 8   . The drive member  1182  is configured to deploy the staples from a cartridge body through the cartridge deck by slidably advancing the sled  1162  distally from a first position toward the second position relative to the cartridge pan  1258 ″. The staple cartridge  1220 ″ includes retaining features  1270   a ″,  1270   b ″ defined in a base portion  1252 ″ of a cartridge pan  1258 ″ on opposite sides of a pan slot  1254 . 
     The staple cartridge  1220 ″ differs from the staple cartridge  1220 ′ in that the retaining features  1270   a ″,  1270   b ″ are in the form of tabs that are bent away from the base portion  1252 ″. The retaining features  1270   a ″,  1270   b ″ define collapsible ramps that are configured to resist a movement of the sled  1162  beyond the first position thereby maintaining the firing lockout assembly  1221  ( FIG.  9   ) in the unlocked configuration while the sled  1162  is at the first position. 
     In the illustrated example, the sled  1162  can be slidably moved slightly from the first position before engaging the retaining features  1270   a ″,  1270   b ″. The permissible movement is insufficient to disengage the sled  1162  from the latch member  1222  and, accordingly, is insufficient to prematurely transition the firing lockout assembly  1221  to the locked configuration. As a distal portion of the sled  1162  engages the retaining features  1270   a ″,  1270   b ″, an additional advancement of the sled  1162  is resisted by the retaining features  1270   a ″,  1270   b″.    
     When a drive force exerted by the drive member  1182  on the sled  1162  exceeds the predetermined driving force, the sled  1162  is advanced over the retaining features  1270   a ″,  1270   b ″. In certain instances, the retaining features  1270   a ″,  1270   b ″ are collapsed under the sled  1162  when the drive force exerted by the drive member  1182  on the sled  1162  exceeds the predetermined driving force. 
       FIGS.  17  and  18    illustrate a staple cartridge  1320  similar in many respects to other staple cartridges described elsewhere herein such as, for example, the staple cartridges  220 .  1220 .  1220 ′. Staples are deployed from the staple cartridge  1320  through a cartridge deck  1355  into the tissue via staple drivers motivated by a sled  1362  in a similar manner to that described in connection loading units  16 ,  16 ′,  1100  of  FIGS.  1 - 8   . The staples and the staple drivers are stored in a cartridge body  1359  of the staple cartridge  1320 . 
     Further to the above, the sled  1362  of an unfired staple cartridge  1320  is maintained at a default first position using retaining features  1370   a ,  1370   b  defined in proximal portions of sidewalls of the cartridge pan  1358 . In the example illustrated in  FIG.  17   , retaining features  1370   a ,  1370   b  are in the form of leaf springs projecting inward. The leaf springs can be stamped or formed in the sidewalls of the cartridge pan  1358 . The retaining feature  1370   a  includes a base attached to, and protruding from, a sidewall of the cartridge pan  1358 . An apex portion extends from the base, and is dimensioned to pass through cutouts (e.g., cutout  1374   a ) defined in the cartridge body  1359 , and into the detents defined in sidewalls of the sled  1362  (e.g., detent  1372   a ). The retaining feature  1370   a  defines a ramp that resists a distal advancement of the sled  1362  up to a predetermined driving force. 
       FIG.  19    illustrates an alternative staple cartridge assembly  1450  similar in many respects to the cartridge assembly  1250 . For example, like the staple cartridge assembly  1250 , the staple cartridge assembly  1450  includes a staple cartridge  1420  that includes a sled  1462  configured to deploy staples from a cartridge body through a cartridge deck by slidably advancing the sled  1462  distally from a first position toward the second position relative to the cartridge pan  1458 . When an unfired staple cartridge  1420  is properly assembled with an elongated channel  1457  of a loading unit, a firing lockout assembly  1221  is transitioned into an unlocked configuration to permit advancement of a drive member  1182  distally to motivate the sled  1462  to deploy the staples. 
     The staple cartridge assembly  1450  differs from the staple cartridge assembly  1250  in that the elongated channel  1457  includes retaining features  1470   a ,  1470   b  in the form of grooves, bores, apertures, or detents. The retaining features  1470   a ,  1470   b  are configured to receive sled protrusions  1472   a ,  1472   b  through cutouts  1474   a ,  1474   b  defined in the base portion of the cartridge pan  1458 . The retaining features  1470   a ,  1470   b  are configured to resist a movement of the sled  1462  up to a predetermined force. When the driving force of the drive member  1182  is greater than the predetermined force, the sled  1462  is advanced distally beyond the first position causing the sled protrusions  1472   a ,  1472   b  to exit the retaining features  1470   a ,  1470   b.    
       FIGS.  20 - 21    illustrate an alternative staple cartridge assembly  1550  similar in many respects to the cartridge assemblies  1250 ,  1450 . The staple cartridge assembly  1550  includes a staple cartridge  1520  similar in many respects to other staple cartridges described elsewhere herein such as, for example, the staple cartridges  220 ,  1220 ,  1220 ′,  1220 ″,  1420 . Staples are deployed from the staple cartridge  1520  through a cartridge deck  1555  into tissue via staple drivers motivated by a sled  1562  in a similar manner to that described in connection loading units  16 ,  16 ′,  1100  of  FIGS.  1 - 8   . The drive member  1182  is configured to deploy the staples from a cartridge body through the cartridge deck  1555  by slidably advancing the sled  1562  distally from a first position toward the second position relative to a cartridge pan  1558 . 
     The staple cartridge  1520  includes one or more retaining features (e.g., retaining features  1570   a ,  1570   b ) that are configured to resist a distal advancement of the sled  1562  until the staple cartridge  1520  is fully seated, or assembled, with an elongated channel  1557  of a loading unit. In the illustrated example, a retaining feature  1570   b  is in the form of a collapsible leaf spring defined in a cartridge pan  1558  by bending an existing pan sheet metal. In the illustrated example, the retaining feature  1570   b  comprises a first portion bent towards the cartridge deck  1555  and a second portion bent away from the cartridge deck  1555 . A curved portion extends between, and connects, the first portion and the second portion. In the illustrated example, the second portion is slightly longer than the first portion. 
     Insertion of the staple cartridge  1520  into the elongated channel  1557 , as illustrated in  FIG.  21   , causes the retaining features  1570   a ,  1570   b  to be collapsed, or flattened, against the elongated channel  1557 , which allows the sled  1562  to be moved distally by the drive member  1182 . The retaining features  1570   a ,  1570   b  resist an advancement of the sled  1562  until their collapse by the insertion of the staple cartridge  1520  into the elongated channel  1557 . In other words, the retaining features  1570   a ,  1570   b  are configured to maintain the sled  1562  at the first position until the staple cartridge  1520  is inserted into the elongated channel  1557 . In doing so, the retaining features  1570   a ,  1570   b  ensure that the sled  1562  transitions the firing lockout assembly  1221  to the unlocked configuration to allow advancement of the drive member  1182 . 
       FIGS.  22 - 24    depict an alternative staple cartridge  1620  with a retaining feature  1670  similar in many respects to the staple cartridge  1520  and its retaining features  1570   a ,  1570   b . For example, the retaining feature  1670  is also in the form of a collapsible leaf spring defined in a cartridge pan  1658  by bending an existing pan sheet metal. However, unlike the retaining features  1570   a ,  1570   b , the retaining feature  1670  is not collapsed, or flattened, by the insertion of the staple cartridge  1620  into an elongated channel of a loading unit. Instead, a sled  1662  of the staple cartridge  1620  includes a groove, aperture, bore, or detent  1672  configured to receive the retaining feature  1670 , as illustrated in  FIG.  22   . 
     Like other collapsible retaining features described elsewhere herein, the retaining feature  1670  is configured to maintain the sled  1662  at a first position thereby ensuring an unlocked configuration of the firing lockout assembly  1221  by a sustained engagement between the latch member  1222  and the sled  1662 . When a drive force exerted by the drive member  1182  against the sled  1662  exceeds a predetermined threshold, the retaining feature  1670  collapses out of the detent  1672  permitting further advancement of the sled  1662 . 
     In the illustrated example, the retaining feature  1670  includes a first portion  1671 , a second portion  1673 , and an intermediate bent portion  1675  extending between, and connecting, the portions  1671 ,  1673 . The portion  1671  includes an aperture  1679 . During assembly, as illustrated in  FIG.  24   , a hook member  1681  engages the portion  1671  at the aperture  1679  to temporarily pull the retaining feature  1670  back to permit the sled  1662  to be slidably moved to the first position. The hook member  1681  then releases the portion  1671 , which allows the retaining feature  1670  to be received in the detent  1672 . 
     Referring now to  FIGS.  25 - 28   , a staple cartridge assembly  1750  is similar in many respects other staple cartridge assemblies described elsewhere herein such as, for example, the staple cartridge assembly  1250 . For example, the staple cartridge assembly  1750  includes an elongated channel  1757  dimensioned and designed to receive and releasably retain a staple cartridge  1720  similar in many respects to other staple cartridges described elsewhere herein such as, for example, the staple cartridge  220 .  1220 . Staples are deployed from the staple cartridge  1720  through a cartridge deck into tissue via staple drivers motivated by the sled  1762  in a similar manner to that described in connection loading units  16 ,  16 ′,  1100  of  FIGS.  1 - 8   . The staples and the staple drivers are stored in a cartridge body of the staple cartridge  1720 . During firing, the working end of the drive member  1182  distally advances the sled  1762  from a first position toward a second position within the cartridge body to cause the staple drivers to deploy the staples. 
     Like the staple cartridge assembly  1250 , the staple cartridge assembly  1750  includes a retaining feature  1770  disposed in the elongated channel  1757 . In the illustrated example, the retaining feature  1770  is in the form of a leaf spring flattened, or at least partially flattened, in a biased configuration by a hard stop that includes hard stop portions  1771   a ,  1771   b  that are defined in opposing side walls  1757   a ,  1757   b  of the elongated channel  1757 . When an unfired staple cartridge  1720  is properly assembled with the elongated channel  1757 , the sled  1762  presses the hard stop portions  1771   a ,  1771   b  into the opposing side walls  1757   a ,  1757   b , respectively, thereby allowing the retaining feature  1770  to be released from the hard stop portions  1771   a ,  1771   b.    
     A distal portion of the retaining feature  1770  then engages a corresponding detent  1772  in the sled  1762  pulling and maintaining the sled  1762  at a first position corresponding to an unlocked configuration of the lockout firing assembly  1221 . In the illustrated example, the engagement between the retaining feature  1770  and that the detent  1772  permits a slight movement of the sled  1762  within a predefined threshold distance “d” without transitioning the firing lockout assembly  1221  to the locked configuration. 
     As described in greater detail was other retaining features of the present disclosure, the retaining feature  1770  is configured to resist an advancement of the sled  1762  up to a predetermined force. When the driving force of the drive member  1182  is greater than the predetermined force, the sled  1762  is released from the retaining feature  1770 , and is advanced distally beyond the first position. The advancement of the sled  1762  over the retaining feature  1770  resets the retaining feature  1770  into a locking engagement with the hard stop portions  1771   a ,  1771   b.    
     The retaining feature  1770  is then maintained in a flattened, or at least partially flattened, configuration by the hard stop portions  1771   a ,  1771   b  until another unfired staple cartridge  1720  is inserted into the elongated channel  1757 . In the illustrated example, maintaining the retaining feature  1770  in a flattened, or at least partially flattened, the configuration reduces drag on the drive member  1182  during the remainder of the firing. 
     In the illustrated example, the sled  1762  include one or more features  1773  designed and dimensioned to engage and depress the hard stop portions  1771   a ,  1771   b  into the opposing side walls  1757   a ,  1757   b . The hard stop portions  1771   a ,  1771   b  can be spring biased such that they return to a locking engagement with the retaining feature  1770  after disengaging from the one or more features  1773 . 
     In various aspects, one or more of the sled positioning and/or retaining mechanisms described in the present disclosure can be combined position and/or maintain the sled in a staple cartridge prior to and after insertion of the staple cartridge into an elongated channel of the loading unit. For example, a first positioning and/or retaining mechanism can be employed to maintain the sled at a first position within the staple cartridge prior to insertion of the staple cartridge into the elongated channel. Then, second positioning and/or retaining mechanism can be employed to maintain the sled at the first position within the staple cartridge after the insertion of the staple cartridge into the elongated channel. 
     In the example illustrated in  FIGS.  25 - 28   , the one or more features  1773  can be received in corresponding apertures or cutouts of a cartridge pan, as described in connection with the loading unit  1200  of  FIGS.  11 - 13   . The features  1773  maintain the sled at the first position within the staple cartridge  1720  prior to insertion of the staple cartridge  1720  into the elongated channel  1757 . After the insertion, however, the sled  1762  is maintained at the first position by the retaining feature  1770 . Accordingly, a staple cartridge assembly (e.g., staple cartridge assembly  1750 ) can be configured to maintain the sled at the first position differently before insertion than after insertion into an elongated channel. In other words, the insertion of the staple cartridge into the elongated channel may cause an active retaining feature to deactivated, and cause an inactive retaining feature to be activated. 
     Referring to  FIGS.  29 - 30   , a staple cartridge  1820  is similar respects to other staple cartridges described elsewhere herein such as, for example, the staple cartridge  220 . For example, like the staple cartridge  220 , the staple cartridge  1820  includes the knife blade  280  ( FIG.  5   ). A central longitudinal slot  1882  is defined in staple cartridge  220  along a central longitudinal plane  1884 . The knife blade  280  is generally positioned to translate slightly behind a sled  1860  through the central longitudinal slot  1882  in the staple cartridge  1820  to form an incision between rows of stapled body tissue. 
     In various aspects, the sled  1860  is maintained at a first, or home, position by a retaining feature  1855  extending across the central longitudinal slot  1882 . In the illustrated example, the retaining feature  1855  includes a weakened central portion  1885   c  extending between portions  1885   a ,  1885   b  that defined hinging gates attached at one end thereof to sidewalls  1882   a ,  1882   b , respectively. In the illustrated example, the central portion  1885   c  includes a perforated breakable body. In other examples, the central portion  1885   c  may comprise a smaller thickness than the portions  1885   a ,  1885   b.    
     In any event, the central portion  1885   c  is designed and dimensioned to resist an advancement of the sled  1860  up to a predetermined driving force threshold. Beyond the threshold, the knife blade  280  applies a force to the sled  1860  that breaks through the central portion  1885   c  causing the portions  1885   a ,  1885   b  to fold or swing open allowing the sled  1860  move distally beyond the first, or home, position. 
     As described in greater detail elsewhere herein, an incidental bumping or shaking of the unfired staple cartridge may cause an unintended movement of the sled within the unfired staple cartridge.  FIG.  31    illustrates a logic flow diagram of a process  1920  depicting a control program or a logic configuration for detecting  1922  the location of a sled of a powered surgical stapling instrument along a firing path thereof, and adjusting  1924  one or more motor settings, or motor control programs, of the powered surgical stapling instrument based on the location of the sled along the firing path. 
       FIGS.  32 - 34    illustrate a powered surgical stapling instrument  1901  that includes a firing system  1902  configured to detect the location of a sled along a firing path thereof, and adjust one or more motor settings, or motor control programs, based on the location of the sled along the firing path, in accordance with the process  1920 . The firing system  1902  includes a control circuit  1930  configured to perform the process  1920 . In the illustrated example, the control circuit  1930  comprises a controller  1932  that includes a processor  1934  and a memory  1936  storing program instructions, which when executed by the processor  1934 , causes the processor  1934  to perform one or more aspects of the process  1920 . 
     The surgical stapling instrument  1901  further includes a loading unit  1900  similar in many respects to other loading units described elsewhere herein such as, for example, the loading units  1100 ,  1200 . For example, like the loading unit  1100 , the loading unit  1900  includes a drive assembly  1980  that includes a drive member  1982 . A motor assembly  1904  includes a motor configured to move the drive member  1982  along a predefined firing path to advance a sled  1962  distally to deploy staples  1908  from a staple cartridge  1921  into tissue grasped between the staple cartridge  1921  and an anvil assembly  1931 . The sled  1962  includes a plurality of cam surfaces which are positioned to engage and lift the pushers within the staple retention slots of the cartridge body of staple cartridge  1921 . The pushers are positioned within the staple cartridge  1921  to eject the staples  1908  from the cartridge body when the sled  1962  is advanced by the drive member  1982 , as illustrated in  FIGS.  33 ,  34   . 
       FIG.  35    is a graph  1940  illustrating, on the x-axis, the distance (δ) traveled by the drive member  1982  along the firing path from a starting position, and on the y-axis, the firing speed (V) and corresponding electrical load of the motor during a firing stroke of the powered surgical stapling instrument  1901  ( FIG.  32   ), which are represented by lines  1942 ′,  1944 ′,  1946 ′,  1948 ′,  1950 ′,  1952 ′, and lines  1942 ,  1944 ,  1946 ,  1948 ,  1950 ,  1952 , respectively. A segment Δδ SC  along the firing path defines acceptable initial sled-contact locations, where the drive member  1982  is configured to first engage (See  FIG.  33   ) the sled  1962  during advancement of the drive member  1982  along the firing path. In addition, a segment Δδ IS  along the firing path defines acceptable initial staple-contact locations, where the sled  1962 , driven by the drive member  1982 , is configured to first engage (See  FIG.  33   ) the pushers of the staples  1908  within the staple cartridge  1921 . 
     In a successful firing, as illustrated by lines  1942 ,  1944 , the drive member  1982  is configured to initially contact ( 1 M,  2 M) the sled  1982  within the segment Δδ SC , and the sled  1962 , driven by the drive member  1982 , is configured to initially contact ( 1 M′,  2 M′) the pushers of the staples  1908  within the segment Δδ IS . 
     In various aspects, a rapid increase, or a step-up, in the electric load of the motor to a value (F S1 ,  FIG.  33   ) within a predetermined range (F-sled min  to F-sled max ) indicates that an initial contact between the drive member  1982  and the sled  1962  is detected. In various aspects, the control circuit  1930  detects the location of the sled  1962  by monitoring at least one parameter indicative of the electric load of the motor such as, for example, the current draw of the motor. 
     Likewise, a rapid increase, or a step-up, in the electric load of the motor to a value (F S2 ,  FIG.  33   ) within a predetermined range (F-staple min  to F-staple max ), which is greater than the predetermined range (F-sled min  to F-sled max ), indicates that an initial contact between the sled  1962 , driven by the drive member  1982 , and the pushers of the staples  1908  is detected. In various aspects, the control circuit  1930  detects the initial contact between the sled  1962  and the staple pushers by monitoring at least one parameter indicative of the electric load of the motor such as, for example, the current draw of the motor. 
     If the rapid increase in the electric load of the motor is detected within the segment Δδ SC , the control circuit  1930  permits the drive member  1982  to continue advancing the sled  1962  along the firing path at a speed less than or equal to a predetermined maximum speed (V-sled max ) until the sled  1982  engages the pushers of the staple cartridge  1921 , which is characterized by another rapid increase in the electric load of the motor to a value (F S2 ,  FIG.  33   ), as discussed above. The detection of the initial contact between the sled  1962  and the staple pusher causes control circuit  1930  to ramp up ( 1 R,  2 R) the speed of the of the drive member  1982  to a speed greater than a predetermined minimum speed (V-firing min ) and less than or equal to a predetermined maximum speed (V-firing max ). 
     If, however, the control circuit  1930  fails ( 4 M) to detect the location of the sled  1962  within the segment Δδ SC , as illustrated by line  1950 , the control circuit  1930  may cause the drive member  1982  to stop ( 4 R) by causing the motor assembly  1904  to stop the motor, for example. The control circuit  1930  may further prompt a user through a user interface  1909  to replace the staple cartridge, as the absence of the sled  1962  can be due to an attachment of a previously fired staple cartridge to the cartridge channel of the loading unit  1900 , or the absence of a staple cartridge. If the user approves, the drive member  1982  is returned (b) to the starting position. If, however, the user is confident that an unfired staple cartridge has been attached to the cartridge channel, the sled  1962  may have been moved or misaligned due to an incidental bumping of the staple cartridge. 
     To resolve the issue, the control circuit  1930  prompts the user for permission to continue (a) advancing the drive member  1982  until a predetermined maximum threshold value δ max  of travel without sled detection is reached ( 5 M,  5 R). If the sled  1962  is not detected, and the predetermined maximum threshold value δ max  has been reached, the control circuit  1930  causes the drive member to be returned to its starting position ( 5 R′). 
     If, however, the sled  1962  is detected ( 6 M,  6 R) prior to reaching the predetermined threshold value δ max , the control circuit  1930  may permit an additional advancement ( 6 R′) of the drive member  1982  in a predetermined segment Δδ SL  to couple the drive assembly  1980  to the sled  1962 , as described in greater detail below. The predetermined segment Δδ SL  defines a functional window of sled travel for ensuring that a coupling between the drive member  1982  and the sled  1962  has occurred. 
     The control circuit  1980  then causes the motor to retract the drive member  1980  to its starting position, which causes the sled  1962  to return to its home position ( 6 R″) within the unfired staple cartridge. The control circuit  1930  may further prompt the user to push down any staples  1908  incidentally lifted above the cartridge deck by the inadvertent advancement of the sled  1962 . Once the sled is returned to the home position, the control circuit  1930  may prompt the user to reinitiate (c) the firing stroke. 
     Further to the above, a successful detection ( 1 M) of the sled  1962  within the segment Δδ SC , accompanied by a failure ( 3 M′) to detect an initial contact between the sled  1962  and the staple pushers within the segment Δδ IS , causes the control circuit  1930  to stop ( 3 R) the advancement of the drive member  1982  at, or about, the end of segment Δδ IS . The control circuit  1930  may further cause the drive member  1982  to return to the starting position. 
     Although the process  1920  is described as being executed by a control circuit  1930 , this is merely for brevity, and it should be understood that the process  1920 , and other processes described elsewhere herein, can be executed by circuitry that can include a variety of hardware and/or software components and may be located in or associated with various suitable systems described by the present disclosure such as, for example, the combinational logic circuit or the sequential logic circuit. 
     In various forms, the motor of the motor assembly  1904  may be a DC brushed driving motor having a maximum rotation of, approximately, 25,000 RPM, for example. In other arrangements, the motor may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. The motor may be powered by a power source  1910  that, in one form, may comprise a removable power pack. The power source  1910  may comprise, for example, anyone of the various power source arrangements disclosed in further detail in U.S. Patent Application Publication No. 2015/0272575 and entitled SURGICAL INSTRUMENT COMPRISING A SENSOR SYSTEM, the entire disclosure of which is hereby incorporated by reference herein. 
     In at least one example, the surgical stapling instrument  1901  is implemented as a hand-held surgical instrument similar in many respects to the surgical instrument system  10  of  FIG.  1   . In another example, the surgical stapling instrument  1901  is implemented as a robotic surgical stapling instrument similar to those disclosed in U.S. Pat. No. 9,072,535, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, which is hereby incorporated by reference herein in its entirety. 
     In various examples, the surgical instrument  1901  includes sensors  1938  that comprise one or more sensors configured to monitor a parameter indicative of the position of the drive member  1982  along the firing path. The sensors  1938  may further include one or more sensors configured to monitor the current draw of the motor. Readings sensors  1938  can aid the control circuit  1930  detect the presence of the drive member  1982  is in the segment Δδ SC  or the segment Δδ IS , detect an initial contact between the drive member  1982  and the sled  1962 , and/or detect an initial contact between the sled  1962 , driven by the drive member  1982 , and the pushers of the staples  1908 , for example. 
     In various aspects, the sensors  1938  may include various other sensors such as, for example, a magnetic sensor, such as a Hall effect sensor, a strain gauge, a pressure sensor, an inductive sensor, such as an eddy current sensor, a resistive sensor, a capacitive sensor, an optical sensor, and/or any other suitable sensor to perform one or more aspects of the process  1920 , for example. 
     Referring now to  FIGS.  36 - 38   , a staple cartridge  2020  includes a retaining feature  2072  configured to maintain a sled  2062  within the staple cartridge  2020  at a home, or start, position. The staple cartridge  2020  is similar in many respects to other staple cartridges disclosed elsewhere herein such as, for example, the staple cartridges  1520 ,  1620 . To resist a movement of the sled  2062  due to an incidental bumping or shaking of the staple cartridge  2020 , a cartridge pan  2058  of the staple cartridge  2020  includes one or more retaining features (e.g., retaining features  2020 ) configured to matingly engage the sled  2062  and resist a movement of the sled  2062  up to a predetermined force. 
     In the illustrated example, the retaining feature  2072  is in the form of a leaf spring projecting, or bent, inward. The leaf spring can be stamped or formed in a base proximal portion of the cartridge pan  2058 . The retaining feature  2072  includes a base attached to, and protruding from, the base portion of the cartridge pan  2058 . An apex portion extends from the base, and is dimensioned to pass through cutouts (e.g., cutout  2022 ) defined in the cartridge pan  2058 , and into the detents defined in sidewalls of the sled  2062  (e.g., detent  2063 ). The retaining feature  2072  defines a ramp that resists a distal advancement of the sled  2062  up to a predetermined driving force. The retaining feature  2072  is flattened by the advancement of the sled  2072  when a drive member (e.g., drive member  1982 ) exerts a driving force on the sled  2072  greater than the predetermined driving force. 
     The staple cartridge  2020  includes a sled detection circuit  2073  configured to determine whether the sled  2062  is outside the home, or starting, position. The sled detection circuit  2073  includes the retaining feature  2072  and a wire, or rod,  2071  extending from a distal portion  2075  of the retaining feature  2072  through a groove  2077  defined in a proximal portion  2078  of the retaining feature  2072 . The wire  2071  terminates in an electrical contact  2079  such as for example a pogo pin. The electrical contact  2079  is configured to transition the sled detection circuit  2073  between a closed configuration while the retaining feature  2072  is bent as illustrated in  FIG.  36   , and an open configuration while the retaining feature  2072  is flattened by the sled  2062 , as illustrated in  FIG.  37   . 
     Accordingly, a control circuit such as, for example, the control circuit  1930  of the surgical instrument  1901  may employ the sled detection circuit  2073  to determine whether the sled  2062  is outside the home, or starting, position by detecting whether or not the sled detection circuit  2073  has transitioned from the closed configuration to the open configuration. A switch of the sled detection circuit  2073  from the closed configuration to an open configuration signals the control circuit  1930  that the sled  2062  has been distally advanced beyond the home, or starting, position. Further, a return of the sled detection circuit  2073  to the closed configuration signals the control circuit  1930  that the sled detection circuit  2073  has been returned to the home, or starting, position. 
     Referring now to  FIG.  39   , a staple cartridge assembly  2150  can be used with a loading unit such as, for example, the loading units  1100 ,  1200 . In the illustrated example, the staple cartridge assembly  2150  includes an elongated channel  2157  dimensioned and designed to receive and releasably retain a staple cartridge  2120  similar in many respects to other staple cartridges described elsewhere herein such as, for example, the staple cartridge  220 . For example, staples also are deployed from the staple cartridge  2120  through a cartridge deck into tissue via staple drivers, or pushers, motivated by a sled  2162  in a similar manner to that described in connection loading units  16 ,  16 ′,  1100  of  FIGS.  1 - 8   . The staples and the staple drivers are stored in a cartridge body of the staple cartridge  2120 . 
     A cartridge pan  2158  is attached to the bottom of the cartridge body to prevent the staple drivers from falling out of the staple cartridge  2120 . The cartridge pan  2158  includes a pan slot  2154  that is aligned with a cartridge slot defined in the cartridge deck. The pan slot  2154  is also aligned with a channel slot  2153  defined in a base portion  2152  of the elongated channel  2157 . During firing, the working end  1184  of the drive member  1182  slidably moves through the cartridge slot, the pan slot  2154 , and the channel slot  2153  distally advancing the sled  2162  from a first position toward a second position within the cartridge body to cause the staple drivers to deploy the staples through the cartridge deck. 
     As described above in greater detail, a sled such as, for example, the sled  2162  can move from its home, or starting position, due to an incidental bumping or shaking of the staple cartridge  2120 . To detect such movement, the staple cartridge assembly  2150  includes a sled detection circuit  2160  configured to detect configured to detect the location of the sled  2162  as the home, or starting position and additional locations distal to the home, or starting position through a series of spaced apart electrical contacts  2170   a ,  2170   b  on opposite sides of the channel slot  2153 . When corresponding electrical contacts  2172   a ,  2172   b  of the sled are positioned against a pair of the electrical contacts  2170   a ,  2170   b , the sled detection circuit  2160  is transitioned into the closed configuration, and a signal unique to such location, as illustrated in  FIG.  41   , is transmitted to a control circuit such as, for example, the control circuit  1930 . 
     The control circuit  1930  can determine the position of the sled  2162  based on the received signal. For example, the memoryl 936  may store an algorithm, an equation, or a look-up table for determining the position of the sled based on one or more parameters of the received signals. The processor  1934  may employ such algorithm, equation, and/or look-up table to determine the position of the sled based on readings of the one or more parameters. In one example, the readings are current or voltage readings indicative of the position of the sled  2162 . 
     In at least one example, the sensors  1938  include a current sensor configured to measure the current passing through the sled detection circuit  2160  in the closed configuration. For a given voltage, the measured current value will change depending on the resistance.  FIG.  41    illustrates example resistances associated with different positions of the sled  2162  along the firing path. Each position is designed to yield a unique resistance and, as such, a unique current value associated with the position. Accordingly, the current readings of the current sensor can aid a control circuit (e.g., control circuit  1930 ) in determining whether the sled  2162  is in the home, or starting, position or in other more distal positions. 
     As illustrated in  FIG.  40   , an inherent baseline resistance exists in the sled detection circuit  2160  leading back to the control circuit  1930 . Each time the sled  2162  completes the sled detection circuit  2160 , additional resistance inherent to the lines in the channel will increase the total resistance and, as such, yielding unique current readings per each position along the firing path. In various aspects, intentionally high-resistance circuit material and/or actual resistors may be used at each contact-point. 
     In the illustrated examples, the electrical contacts  2170   a ,  2170   b  are raised above the base portion  2152  of the elongated channel  2157 , and define biasing members configured to ensure a good connection with the staple cartridge  2120 . The electrical contacts  2170   a ,  2170   b  extend through cutouts  2174   a ,  2174   b  defined in the base portion  2159  of the cartridge pan  2158 . In various aspects, the cartridge pan  2158  is coated with a thin film electrical insulator to prevent shorting. Similarly, the internal surface of the base portion  2152  can be coated with a thin film electrical insulator to prevent shorting. The electrical contacts  2170   a ,  2170   b  extend through the electrical insulator film of the cartridge pan  2158 . 
     In various aspects, signals from the sled detection circuit  2160  indicate the completion of a firing stroke. Electrical contacts  2170   a ,  2170   b  can be positioned at, or about, the end of the firing path. In the illustrated examples, electrical contacts  2170   a ,  2170   b  are position at, or about, a distance 60 mm from the home, or starting, position. When the sled  2162  reaches the end of the firing stroke, the electrical contacts  2172   a ,  2172   b  engage the electrical contacts  2170   a ,  2170   b  transitioning the sled detection circuit  2160  to a closed configuration, and yielding a unique signal indicative of the completion of the firing stroke. 
     In the illustrated example, the sled  2162  is insulated except for a conductive portion  2161  that defines the electrical contacts  2172   a ,  2172   b . In other examples, however, the entire sled  2162  can be comprised of a conductive material. In such instances, the whole sled  2162  becomes part of the sled detection circuit  2160 . 
     Referring now to  FIG.  41   , a staple cartridge  2220  is depicted. The staple cartridge  2220  is similar in many respects to other staple cartridges disclosed elsewhere herein such as, for example, the staple cartridges  1220 ′,  1220 ″,  1320 ,  1620 . For example, the staple cartridge  2220  includes a retaining feature  2270  configured to resist incidental movements of a sled to  2262  within the staple cartridge  2220  due to, for example, an incidental bumping of the staple cartridge  2220 . 
     In addition, the staple cartridge  2220  is further equipped with a sled reset circuit  2264  configured to retract the sled  2262  to a home, or starting, position  2267 . In the illustrated example, the sled  2262  includes one or more apertures, bores, grooves, or detents (e.g., detent  2272 ) defined in a sled base  2263 . The detent  2272  is aligned with and configured to receive the retaining feature  2270 . A driving force greater than a predetermined threshold is needed to separate the retaining feature  2270  from the sled  2262 . Accordingly, the retaining feature  2270  is configured to resist an advancement of the sled  2262  up to the predetermined threshold. 
     Furthermore, the retaining feature  2270  rides in a channel  2266  defined in a cartridge pan  2258  of the staple cartridge  2220 . A proximal wall  2266   a  of the channel  2266  defines a proximal stopping position for the retaining feature  2270 , which corresponds to the home, or starting, position  2267  of the sled  2262 . A distal wall  2266   b  of the channel  2266  defines a distal stopping position of the retaining feature  2270  within the channel  2266 . Since the retaining feature  2270  is not permitted to move beyond the distal wall  2266   b , an additional movement of the sled  2262  forces the sled  2262  to decouple from the retaining feature  2270 . 
     Further to the above, the channel  2266  permits incidental movements of the sled  2262  and the retaining feature  2270  without decoupling the sled  2262  from the retaining feature  2270  within a predetermined range defined by the length of the channel  2266 , or the distance between the proximal wall  2266   a  and the distal wall  2266   b . Prior to firing however the sled reset circuit  2264  is activated to retract the retaining feature  2270  to abut against the proximal wall  2266   a . The retraction of the retaining feature  2270  causes the sled  2262  to be retracted to the home, or starting, position  2267 . In the illustrated example, the sled reset circuit  2264  includes a solenoid  2269  that, when activated, is configured to pull, or retract, a wire or rod  2268  coupled to the retaining feature  2270 . 
     As described elsewhere herein, the sled  2262  of an unfired staple cartridge  2220  prevents the firing lockout assembly  1221  from transitioning to a locked configuration while the sled  2262  is at the home, or starting, position  2267 . Accordingly, retraction of the sled  2262  by the sled reset circuit  2264  ensures that an unfired staple cartridge  2220  is not mistaken for a previously fired staple cartridge  2220  due to an incidental advancement of the sled to from the home, or starting, position  2267 . Notably, the sled reset circuit  2264  is capable of retracting the sled  2262  only when the retaining feature  2270  is coupled to the sled  2262 . Once the sled  2262  is advanced distally by the drive member beyond its coupling engagement was the retaining feature  2270 , the staple cartridge  2220  is deemed as fired. 
     In various aspects, the sled reset circuit  2264  can be incorporated into other staple cartridges disclosed elsewhere herein. In certain aspects, the sled reset circuit  2264  can be coupled to the control circuit  1930 , and can be activated by the control circuit  1930 , in response to a determination by the control circuit  1930  that the sled  2262  is not at the home, or starting, position  2267 . In such aspects, one or more of the sensors  1938  may detect that the sled  2262  is at a position beyond the home, or starting position  2267 . In response, the control circuit  1930  may activate the sled reset circuit  2264  to return the sled  2262  to the home, or starting, position  2267  prior to initializing the firing stroke. 
     Referring now to  FIGS.  42 - 44   , an alternative embodiment of a sled reset circuit  2364  is depicted. Like the sled reset circuit  2264 , the sled reset circuit  2364  is also configured to retract a sled  2362  to a home, or starting position within a predetermined range of motion of the sled  2362  where a retaining feature  2370  remains movably coupled to the sled  2362 . Beyond the predetermined range, a drive member motivates the sled  2362  to decouple from the retaining feature  2370 . The retaining feature  2370  is then retracted to a proximal starting position by the sled reset circuit  2364 . 
     Referring now to  FIGS.  45 - 46   , a surgical stapling assembly  2450  includes a staple cartridge  2420  including a sled  2462 . The staple cartridge assembly  2450  is transitionable to a closed configuration to grasp tissue in a similar manner to that described in connection with other staple cartridges assemblies such as, for example, the staple cartridge assemblies  1150 ,  1250 . A working end  2484  of a drive member (e.g., drive member  1182 ) defines an I-beam configured to effect a firing of the surgical stapling assembly  2450 . 
     The working end  2484  includes a first flange  2484   a , a second flange, a vertical strut  2484   c  interconnecting the first flange  2484   a  and the second flange, and a knife supported on or formed into the vertical strut  2484   c . The second flange is positioned to be slidably received within a channel of an anvil assembly (e.g., anvil assembly  1130 ) and the first flange  2484   a  is positioned to be slidably positioned along an outer surface of surgical stapling assembly  2450 . Actuation sled  2462  is disposed within cartridge assembly  2450  at a position distal of the working end  2484 . 
     In various aspects, a flexible arm  2470  extends from the working end  2484  into a channel  2471  defined in a side wall of a cartridge body  2459  of the staple cartridge  2420 . In illustrated example, the flexible arm  2470  defines a leaf-spring arm member that passes through the channel  2471  and latches onto a distal portion of the sled  2470 . The flexible arm  2470  is configured to retract the sled  2462  to a home, or starting, position. 
     In the channel  2471 , the flexible arm  2470  is flattened such that it is naturally pressing into the side of the sled  2462 . In at least one example, a distal end of the flexible arm  2470  passes the distal end of the sled  2462 . A tab  2472  extends out from the flexible arm  2470 , in the relaxed position, to latch onto the front edge of the sled  2462 . The motion of the working end  2484  that occurs prior to driving the knife of the staple cartridge assembly  2450  during a full firing stroke will allow for the flexible arm  2470  to pull the sled  2462  back into the home, or starting, position as long as the sled  2462  is within a threshold defined by the length of the side channel  2471 . 
       FIGS.  47 - 51    illustrate various aspects of a sled resetting mechanism  2500  for retracting a sled of a staple cartridge (e.g., staple cartridge  2520 ) to a home position (H) prior to firing a surgical instrument to deploy staples of the staple cartridge  2520 . As discussed elsewhere herein, a sled of an unfired staple cartridge can be inadvertently moved if the staple cartridge is bumped or shaken, which may cause the staple cartridge to be mistakenly deemed as fired and/or may cause a firing lockout assembly to be activated. The sled resetting mechanism  2500  is configured to return a sled that was inadvertently moved to its home position (H) within the staple cartridge as long as the sled has not moved beyond a predetermined distance (d 1 ) from the home position (H). 
       FIG.  47    illustrates a sled  2562  of the staple cartridge  2520  at a position distal to the home position (H) but proximal to the distal position (A) defined by the predetermined distance (d 1 ). Prior to firing, a sled resetting member  2592  retracts the sled  2562  to the home position (H). The sled resetting member  2592  includes catcher  2595 , which can be in the form of a hook or a bent portion, configured to engage a distal portion of the sled  2562  to return the sled  2562  to the home position (H). 
     In various aspects, a portion of the sled resetting member  2592  extends, and is slidably movable below the sled  2562  such as, for example, within a channel defined in a cartridge pan of the staple cartridge  2520 . In at least one example, as illustrated in  FIG.  51   , the sled resetting member  2592  is manually operable by an actuation member  2593  defined in a handle  2507 . A user can pull the actuation member  2593  proximally to return the sled  2562  to the home position (H) prior to activation of the firing mechanism. 
     In another example, as illustrated in  FIGS.  49  and  50   , the sled resetting member  2592  is powered by a motor assembly  2504  similar in many respects to the motor drive assembly  1904  of the surgical instrument  1901 . In the illustrated example, the motor drive assembly  2504  includes a linear threaded coupler  2598  operably connected to the sled resetting member  2592 . In the illustrated example, the motor assembly  2504  is housed in a handle  2510  that includes a trigger member  2512 . A movement of the trigger member  2512  to a first position causes the motor assembly  2504  to retract the sled resetting member  2592  thereby returning the sled  2562  to the home position (H). A second movement of the trigger member  2512  from the first position to a second position activates the firing stroke, or firing motion, to deploy staples from the staple cartridge  2520 . 
     The sled resetting mechanism  2500  can be implemented in combination with other suitable embodiments of the present disclosure such as, for example, a sled detection circuit. Further, the sled resetting mechanism  2500  can be implemented in combination with suitable components of the surgical stapling instrument  1901 . For example, the control circuit  1930  may determine that the sled is at a position different than the home position based on the sled detection circuit. In response, the control circuit  1930  may cause the motor assembly  2504  to return the sled to the home position, which can be verified by the sled detection circuit, for example. 
     In use, the sled  2562  is returned to the home position (H) by the sled resetting member  2592 , as illustrated in  FIG.  47   . Then, a drive member (e.g. drive member  1182 ), is configured to advance a working end thereof (e.g. working end  1184 ) to engage the sled  2562  to advance the sled  2562  to deploy staples from the staple cartridge  2520 . In various aspects, as illustrated in  FIG.  48   , the sled resetting member  2592  includes a raised portion  2597 , which can be in the form of a ramp, positioned proximal to the catcher  2595 . During advancement of the drive member  2582 , the working end  2584  may engage the raised portion  2597  prior to engaging the sled  2562 , which causes the catcher  2595  to move out of a firing path  2503  of the sled  2562 . In at least one example, the working end  2584  causes the catcher  2595  to drop into the channel defined in the cartridge pan of the staple cartridge  2520 , which permits further advancement of the sled  3562 . 
     In various aspects, setting acceptable and/or unacceptable sled positions, or sled distances from the home position, which is also referred to herein as a functional window, along a firing path can depend, at least in part, on staple cartridge size. Accordingly, to accurately set such positions, or distances, surgical cartridge may include identification codes which can be communicated to a control circuit (e.g., control circuit  1930 ) after attachment of the staple cartridge to the surgical instrument (e.g., surgical instrument  1901 ). The communication may occur through a wired connection with the staple cartridge, or wirelessly. 
     In various aspects, the control circuit may select a suitable function window given the expected location of the sled contact based on the communicated identification code of the cartridge. In various aspects, the firing system may further adjust one or more parameters of a predetermined firing program such as, for example, the force/velocity/stroke of both the sensing region based on the identification of the cartridge and/or the actuation region based on the timing/location of the sensed sled relative to its expected location. 
     Referring now to  FIGS.  52 - 56   , a loading unit  2600  is similar in many respects to other loading units described elsewhere herein such as, for example, the loading units  1100 ,  1200 . For example, the loading unit  2600  includes a staple cartridge assembly  2650  and an anvil assembly  2630 . At least one of the anvil assembly  2630  and the staple cartridge assembly  2650  is movable relative to the other from an open configuration, as illustrated in  FIG.  53   , to a closed configuration, as illustrated in  FIG.  54   , to grasp tissue. Staples are deployed into the tissue from staple cavities  2621  defined in a cartridge body  2622  of a staple cartridge  2620  of the staple cartridge assembly  2650 . The anvil assembly  2630  includes pockets configured to deform the staples. 
     Further to the above, the staple cartridge  2620  includes a cartridge pan  2658  configured to prevent the staples from falling out of the staple cavities  2621 . The cartridge body  2622  is attachable to the cartridge pan  2658  by way projections  2623  receivable in a corresponding cutouts  2653  defined in side walls of the cartridge pan  2658 . In various examples, the cutouts  26523  are sized and shaped to receive the corresponding cutouts  2653  to secure the cartridge body  2622  to the cartridge pan  2657 . 
     In use, the staple cartridge  2620  is inserted into the elongated channel  2657  for assembly therewith. In various aspects, the staple cartridge  2620  and the elongated channel  2657  comprise corresponding locking features. In the illustrated example, pan projections  2656 , which are defined in side walls of the cartridge pan  2658 , are received in L-shaped slots  2659  when the staple cartridge  2620  is inserted into the elongated channel  2657 . 
     The corresponding locking features of the staple cartridge  2620  and the elongated channel  2657  permit a proximal translating motion of the cartridge pan  2658  relative to the elongated channel  2658  to lock the staple cartridge  2620  to the elongated channel  2657 , and a distal translating motion of the cartridge pan  2658  relative to the elongated channel  2658  to unlock the staple cartridge  2620  to the elongated channel  2657 . In the illustrated example, the L-shaped slots  2659  are sized and shaped to permit the corresponding projections  2656  to translate proximally a distance “X” in the long arm of L-shaped slots  2659  thereby locking the staple cartridge  2620  to the elongated channel  2657 , and to translate distally the distance “X” in the long arm of L-shaped slots  2659  thereby unlocking the staple cartridge  2620  from the elongated channel  2657 . 
     In other examples, the projections can be defined in an elongated channel and corresponding L-shaped slots can be defined in a cartridge pan of a staple cartridge. Furthermore, other suitable mating and locking mechanisms can be implemented to produce locked and unlocked configurations of a staple cartridge and an elongated channel. For example, slots with other suitable shapes can replace the L-shaped slot. 
     Further to the above, the locking mechanism of the staple cartridge  2620  to the elongated channel  2657  is implemented automatically during the transition to a closed configuration of the anvil assembly  2630  and the staple cartridge assembly  2650 , as illustrated in  FIGS.  53  and  54   . In certain examples, the anvil assembly  2630  is configured to cause the cartridge pan  2658  to translate proximally relative to the elongated channel  2657  into the locked configuration. In the illustrated example, the anvil assembly  2630  includes camming members  2631  configured to retract the cartridge pan  2658  to the locked configuration as the loading unit  2600  is transitioned into the closed configuration ( FIG.  54   ). 
     In the illustrated example, the cartridge pan  2658  includes a proximal tongue portion  2662  bisected by a pan slot  2663 . The proximal tongue portion  2662  includes cutouts  2661  on opposite sides of the pan slot  2663 . The camming members  2631  are configured to engage proximal edges  2664  of the cutouts  2661  during a closure motion of the loading unit  2600 . As the loading unit  2600  is transitioned to the closed configuration, the camming members  2631  exert a camming force against the proximal edges  2664  of the cutouts  2661  thereby causing the cartridge pan  2658  to translate proximally into the locked configuration. Accordingly, the closure motion of the loading unit  2600  automatically transitions the staple cartridge  2620  into a locked configuration with the elongated channel  2657 . 
     In the illustrated example, to ensure a proper engagement with the camming member  2631  the proximal end of the proximal tongue portion  2662  is bent toward the cutouts  2661  thereby forming the edges  2664 . The camming members  2631  are configured to engage the edges  2664  as the camming members  2631  pivot with the anvil assembly  2630  towards the staple cartridge  2620 . In other example, an anvil assembly including the camming members  2631  can be fixed, and an elongated channel is pivoted towards the anvil assembly to yield a closed configurations. In such examples, the edges  2664  are moved towards the camming members  2631 . When the edges  2664  engage the camming members  2641 , the camming force causes the cartridge pan  2658  to translate proximally to the locked configuration. 
     Further to the above, the elongated channel  2657  includes proximal slots or cutouts  2671  defined in a proximal portion of a base  2672  of the elongated channel  2657 . The cutouts  2671  are laterally or transversely aligned, or at least partially aligned, with the cutouts  2661 . In the unlocked configuration, as illustrated in  FIG.  53   , the cutouts  2661  are distal to the cutouts  2671 . However, in the locked configuration, as illustrated in  FIG.  54   , the cutouts  2661  are longitudinally aligned with cutouts  2671 , or at least are closer to a longitudinal alignment with the cutouts  2671  than in the unlocked configuration. As the camming members  1631  are pivotally moved in the cutouts  2661 ,  2671 , the camming members  2631  are configured to cause the cutouts  2661  to move proximally a distance “X” to be aligned, or at least partially aligned, with the cutouts  2671 , as illustrated in  FIG.  54   . 
     After completion of the firing stroke, a spent staple cartridge  2620  is removed from the elongated channel  2657  by translating the cartridge pan  2658  to the unlocked configuration. In the illustrated example, the cartridge pan  2658  includes a release feature  2655 , which can be in the form of a finger tab. The release feature  2655  is slidably movable distally in a corresponding slot  2620 , defined in nose portion  2626  of the cartridge body  2622 , to transition the staple cartridge  2620  to the unlocked configuration, as illustrated in  FIGS.  55  and  56   . 
     Referring now to  FIGS.  57 - 61   , a staple surgical assembly  2750  includes an elongated channel  2757 , a staple cartridge  2758 , and a retainer  2730 . The staple surgical assembly  2750  is similar in many respects to other staple surgical assemblies described elsewhere herein. For example, the staple surgical assembly  2750  can be incorporated into any suitable surgical instrument described elsewhere herein. 
     In the example illustrated in  FIG.  57   , the staple cartridge assembly  2750  is in a first configuration where the retainer  2730  is assembled with the staple cartridge  2720  to prevent staples from inadvertently falling out of staple cavities of the staple cartridge  2720 . In the first configuration, long tabs  2731  of the retainer  2730  define retainer arms that engage a cartridge pan  2758  of the staple cartridge  2720 , and short tabs  2732  define retainer arms that engage a cartridge body  2721  of the staple cartridge  2720 . The tabs  2731 ,  2732  cooperate to maintain the retainer  2730  pressed against a deck  2722  of the cartridge body  2721  in the first configuration to maintain staples in their staple cavities. In the illustrated example, the cartridge body  2721  includes ledges  2723  extending laterally from the deck  2722 . The ledges  2723  are engaged by the short tabs  2732  in the first configuration. 
     After completion of the firing stroke, a spent staple cartridge  2720  is removed from the elongated channel  2757 , as illustrated in  FIGS.  58 - 61   , by the retainer  2730 . In a second configuration, the long tabs  2731  of the retainer  2730  are inserted through tracks or notches  2724  defined in the cartridge body  2721 , as best illustrated in  FIG.  60   . The tabs  2731  release collapsible members  2755  of the cartridge pan  2558  from corresponding apertures  2756  of the elongated channel  2757  to permit removal of the staple cartridge  2720  from the elongated channel  2757  by the retainer  2730 , as illustrated in  FIG.  61   . 
     In the illustrated example, the collapsible members  2755  are in the form of leaf springs that can be stamped or formed in the sidewalls of the cartridge pan  2758 . The tabs  2731  include hook features  2733  configured to collapse the collapsible members  2755  to release the collapsible members  2755  from the apertures  2756  as the tabs  2731  are advanced in the tracks  2724 , and further configured to form a movable locking-engagement with the collapsed collapsible members  2755  in the second configuration, as illustrated in  FIG.  60   . 
     The retainer  2730  is then pulled away from the elongated channel  2757  to remove the staple cartridge  2720  from the elongated channel  2757 , as illustrated in  FIG.  61   . As the retainer  2730  is pulled away, the hook features  2733  lift the collapsible members  2755  out of the tracks  2724  thereby releasing the staple cartridge  2720  from the elongated channel  2757 . 
     In the illustrated example, the apertures  2756  are defined in sidewalls of the elongated channel  2757  in the form of cutouts. In other examples, the apertures  2756  can be replaced with recesses or slots defined on inner surfaces of the inner walls of the elongated channel  2757 . The recesses or slots are shaped and sized to receive the collapsible members  2755  in their natural state in a similar manner to that illustrated in  FIG.  59    with respect to the apertures  2756 . 
     Referring still to  FIGS.  59 - 61   , a method of using the retainer  2730  to remove a spent staple cartridge  2720  from the elongated channel  2757  is depicted. The method includes decoupling the retainer  2730  from the staple cartridge assembly  2750 . The method further includes inserting the tabs  2731  into the track  2724 , releasing the collapsible members  2755  from the apertures  2756  by the hook features  2733  of the tabs  2731 , and forming a movable locking-engagement between the collapsed collapsible members  2755  and the hook features  2733  in the tracks  2724 . The method further includes pulling the retainer  2730  away from the elongated channel  2757  to remove the spent staple cartridge  2720  from the elongated channel  2757 . 
     Referring now to  FIG.  62   , a staple surgical assembly  2850  includes a quick-release feature that facilitates removal of a staple cartridge  2820  from an elongated channel  2857  of a surgical instrument. The staple surgical assembly  2850  is similar in many respects to other staple surgical assemblies described elsewhere herein. For example, the staple surgical assembly  2850  can be incorporated into any suitable surgical instrument described elsewhere herein. 
     The staple cartridge  2820  includes a cartridge body  2821  and a cartridge pan  2858 . Furthermore, the staple cartridge  2858  includes a cartridge release member  2822  movably disposed in a nose portion  2823  of the cartridge body  2821 . In the illustrated example, the cartridge release member  2822  is linearly movable through a passage  2824  defined in the nose portion  2823  from an unactuated configuration to an actuated configuration. In the unactuated configuration, as illustrated in  FIG.  62   , the cartridge release member  2822  protrudes from the nose portion  2823  through one end of the passage  2824 . When actuated, by applying an external pressure thereto for example, the cartridge release member  2822  moves in the passage  2824 , and protrudes through the other end of the passage  2824 . The cartridge release member  2822  then presses against the elongated channel  2857  to release the staple cartridge  2820  from the elongated channel  2857 . In the illustrated example, the passage  2824  defines a direction of motion for the cartridge release member  2822  that is at an acute angle with the elongated channel  2857   
     The surgical instrument systems described herein are motivated by an electric motor; however, the surgical instrument systems described herein can be motivated in any suitable manner. In certain instances, the motors disclosed herein may comprise a portion or portions of a robotically controlled system. U.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Pat. No. 9,072,535, for example, discloses several examples of a robotic surgical instrument system in greater detail, the entire disclosure of which is incorporated by reference herein. The disclosures of International Patent Publication No. WO 2017/083125, entitled STAPLER WITH COMPOSITE CARDAN AND SCREW DRIVE, published May 18, 2017, International Patent Publication No. WO 2017/083126, entitled STAPLE PUSHER WITH LOST MOTION BETWEEN RAMPS, published May 18, 2017, International Patent Publication No. WO 2015/153642, entitled SURGICAL INSTRUMENT WITH SHIFTABLE TRANSMISSION, published Oct. 8, 2015, U.S. Patent Application Publication No. 2017/0265954, filed Mar. 17, 2017, entitled STAPLER WITH CABLE-DRIVEN ADVANCEABLE CLAMPING ELEMENT AND DUAL DISTAL PULLEYS, U.S. Patent Application Publication No. 2017/0265865, filed Feb. 15, 2017, entitled STAPLER WITH CABLE-DRIVEN ADVANCEABLE CLAMPING ELEMENT AND DISTAL PULLEY, and U.S. Patent Application Publication No. 2017/0290586, entitled STAPLING CARTRIDGE, filed on Mar. 29, 2017, are incorporated herein by reference in their entireties. 
     The surgical instrument systems described herein have been described in connection with the deployment and deformation of staples; however, the embodiments described herein are not so limited. Various embodiments are envisioned which deploy fasteners other than staples, such as clamps or tacks, for example. Moreover, various embodiments are envisioned which utilize any suitable means for sealing tissue. For instance, an end effector in accordance with various embodiments can comprise electrodes configured to heat and seal the tissue. Also, for instance, an end effector in accordance with certain embodiments can apply vibrational energy to seal the tissue. 
     EXAMPLES 
     Various aspects of the subject matter described herein are set out in the following numbered examples. 
     Example 1—A surgical stapling instrument for use with a staple cartridge including a sled and staples. The surgical stapling instrument comprises a firing system. The firing system comprising a motor and a driving member operably coupled to the motor. The motor is configured to cause the driving member to advance the sled to deploy the staples into tissue grasped by the surgical stapling instrument. The driving member is movable by the motor along a predefined firing path. The surgical stapling instrument further comprises a control circuit that is configured to detect a location of the sled along the firing path, and adjust a motor control program based on the location of the sled. 
     Example 2—The surgical stapling instrument of Example 1, wherein the control circuit is configured to determine the location of the sled using a sled detection circuit. 
     Example 3—The surgical stapling instrument of Examples 1 or 2, wherein the motor control program is selected based on an identification key of the staple cartridge. 
     Example 4—The surgical stapling instrument of Examples 1, 2, or 3, wherein the control circuit is configured to detect the location of the sled by monitoring a parameter indicative of an electrical load of the motor. 
     Example 5—The surgical stapling instrument of Examples 1, 2, 3, or 4, wherein the firing path comprises a first segment defining acceptable initial sled-contact locations, and a second segment defining acceptable initial staple-contact locations. 
     Example 6—The surgical stapling instrument of Example 5, wherein a failure to detect the sled in the first segment of the firing pathway causes the control circuit to stop the motor. 
     Example 7—The surgical stapling instrument of Example 6, wherein a failure to detect the sled in the first segment of the firing path further causes the control circuit to issue an alert. 
     Example 8—The surgical stapling instrument of Examples 1, 2, 3, 4, 5, 6, or 7, wherein the control circuit is configured to detect an initial staple contact with the firing system by monitoring the parameter indicative of the electrical load of the motor. 
     Example 9—The surgical stapling instrument of Example 8, wherein a failure to detect the initial staple contact in the second segment causes the control circuit to stop the motor. 
     Example 10—The surgical stapling instrument of Examples 8 or 9, wherein a failure to detect the initial staple contact in the second segment causes the control circuit to issue an alert. 
     Example 11—The surgical stapling instrument of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the control circuit is configured to cause the firing system to retract the sled when the location of the sled is outside a home position range. 
     Example 12—The surgical stapling instrument of Examples 5, 6, 7, 8, 9, 10, or 11, wherein a failure to detect the sled along the firing path up to a predetermined threshold beyond the first segment and the second segment causes the control circuit to cause the motor to return to the home position. 
     Example 13—A loading unit for use with a surgical stapling instrument. The loading unit comprises a shaft and an end effector extending from the shaft. The end effector comprises a first jaw that comprises an anvil. The end effector further comprises a second jaw. At least one of the first jaw and the second jaw is movable relative to the other to grasp tissue. The second jaw comprises an elongated channel comprising channel electrical contacts spaced apart along a length of the elongated channel defining a firing path. The second jaw further comprises a staple cartridge insertable into the elongated channel for assembly therewith. The staple cartridge comprises a cartridge pan, and a sled translatable along the firing path through positions defined by the channel electrical contacts. The loading unit further comprises a sled detection circuit transitionable from an open configuration to a closed configuration when the sled is moved into the positions. 
     Example 14—The loading unit of Example 13, wherein the sled detection circuit is configured to yield a unique electrical signal for each of the positions. 
     Example 15—The loading unit of Examples 13 or 14, wherein the sled comprises sled electrical contacts. 
     Example 16—The loading unit of Example 15, wherein the channel electrical contacts are configured to engage the sled electrical contacts through the cartridge pan. 
     Example 17—The loading unit of Examples 13, 14, 15, or 16, wherein the channel electrical contacts comprise biasing members. 
     Example 18—The loading unit of Examples 13, 14, 15, 16, or 17, wherein the cartridge pan comprises cutouts configured to receive the biasing members. 
     Example 19—The loading unit of Examples 13, 14, 15, 16, 17, or 18, wherein the positions comprise a first position defining a first resistance of the sled detection circuit, and a second position defining a second resistance of the sled detection circuit different than the first resistance. 
     Example 20—A loading unit for use with a surgical stapling instrument. The loading unit comprises a shaft and an end effector extending from the shaft. The end effector comprises a first jaw that comprises an anvil. The end effector further comprises a second jaw. At least one of the first jaw and the second jaw is movable relative to the other to grasp tissue. The second jaw comprises an elongated channel and a staple cartridge insertable into the elongated channel for assembly therewith. The staple cartridge comprises a cartridge pan and a sled translatable relative to the cartridge pan from a home position along a firing path in a firing motion to deploy staples from the staple cartridge. The loading unit further comprises a sled position-resetting mechanism configured to return the sled to the home position from a predefined range of positions distal to the home positions prior to the firing motion. 
     Example 21—The loading unit of Example 20, wherein the sled position-resetting mechanism is configured to releasably engage a distal portion of the sled. 
     While several forms have been illustrated and described, it is not the intention of Applicant to restrict or limit the scope of the appended claims to such detail. Numerous modifications, variations, changes, substitutions, combinations, and equivalents to those forms may be implemented and will occur to those skilled in the art without departing from the scope of the present disclosure. Moreover, the structure of each element associated with the described forms can be alternatively described as a means for providing the function performed by the element. Also, where materials are disclosed for certain components, other materials may be used. It is therefore to be understood that the foregoing description and the appended claims are intended to cover all such modifications, combinations, and variations as falling within the scope of the disclosed forms. The appended claims are intended to cover all such modifications, variations, changes, substitutions, modifications, and equivalents. 
     The foregoing detailed description has set forth various forms of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, and/or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Those skilled in the art will recognize that some aspects of the forms disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as one or more program products in a variety of forms, and that an illustrative form of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. 
     Instructions used to program logic to perform various disclosed aspects can be stored within a memory in the system, such as dynamic random access memory (DRAM), cache, flash memory, or other storage. Furthermore, the instructions can be distributed via a network or by way of other computer readable media. Thus a machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer), but is not limited to, floppy diskettes, optical disks, compact disc, read-only memory (CD-ROMs), and magneto-optical disks, read-only memory (ROMs), random access memory (RAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic or optical cards, flash memory, or a tangible, machine-readable storage used in the transmission of information over the Internet via electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). Accordingly, the non-transitory computer-readable medium includes any type of tangible machine-readable medium suitable for storing or transmitting electronic instructions or information in a form readable by a machine (e.g., a computer). 
     As used in any aspect herein, the term “control circuit” may refer to, for example, hardwired circuitry, programmable circuitry (e.g., a computer processor including one or more individual instruction processing cores, processing unit, processor, microcontroller, microcontroller unit, controller, digital signal processor (DSP), programmable logic device (PLD), programmable logic array (PLA), or field programmable gate array (FPGA)), state machine circuitry, firmware that stores instructions executed by programmable circuitry, and any combination thereof. The control circuit may, collectively or individually, be embodied as circuitry that forms part of a larger system, for example, an integrated circuit (IC), an application-specific integrated circuit (ASIC), a system on-chip (SoC), desktop computers, laptop computers, tablet computers, servers, smart phones, etc. Accordingly, as used herein “control circuit” includes, but is not limited to, electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application specific integrated circuit, electrical circuitry forming a general purpose computing device configured by a computer program (e.g., a general purpose computer configured by a computer program which at least partially carries out processes and/or devices described herein, or a microprocessor configured by a computer program which at least partially carries out processes and/or devices described herein), electrical circuitry forming a memory device (e.g., forms of random access memory), and/or electrical circuitry forming a communications device (e.g., a modem, communications switch, or optical-electrical equipment). Those having skill in the art will recognize that the subject matter described herein may be implemented in an analog or digital fashion or some combination thereof. 
     As used in any aspect herein, the term “logic” may refer to an app, software, firmware and/or circuitry configured to perform any of the aforementioned operations. Software may be embodied as a software package, code, instructions, instruction sets and/or data recorded on non-transitory computer readable storage medium. Firmware may be embodied as code, instructions or instruction sets and/or data that are hard-coded (e.g., nonvolatile) in memory devices. 
     As used in any aspect herein, the terms “component,” “system,” “module” and the like can refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. 
     As used in any aspect herein, an “algorithm” refers to a self-consistent sequence of steps leading to a desired result, where a “step” refers to a manipulation of physical quantities and/or logic states which may, though need not necessarily, take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It is common usage to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. These and similar terms may be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities and/or states. 
     A network may include a packet switched network. The communication devices may be capable of communicating with each other using a selected packet switched network communications protocol. One example communications protocol may include an Ethernet communications protocol which may be capable permitting communication using a Transmission Control Protocol/Internet Protocol (TCP/IP). The Ethernet protocol may comply or be compatible with the Ethernet standard published by the Institute of Electrical and Electronics Engineers (IEEE) titled “IEEE 802.3 Standard”, published in December, 2008 and/or later versions of this standard. Alternatively or additionally, the communication devices may be capable of communicating with each other using an X.25 communications protocol. The X.25 communications protocol may comply or be compatible with a standard promulgated by the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T). Alternatively or additionally, the communication devices may be capable of communicating with each other using a frame relay communications protocol. The frame relay communications protocol may comply or be compatible with a standard promulgated by Consultative Committee for International Telegraph and Telephone (CCITT) and/or the American National Standards Institute (ANSI). Alternatively or additionally, the transceivers may be capable of communicating with each other using an Asynchronous Transfer Mode (ATM) communications protocol. The ATM communications protocol may comply or be compatible with an ATM standard published by the ATM Forum titled “ATM-MPLS Network Interworking 2.0” published August 2001, and/or later versions of this standard. Of course, different and/or after-developed connection-oriented network communication protocols are equally contemplated herein. 
     Unless specifically stated otherwise as apparent from the foregoing disclosure, it is appreciated that, throughout the foregoing disclosure, discussions using terms such as “processing,” “computing,” “calculating,” “determining,” “displaying,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. 
     One or more components may be referred to herein as “configured to,” “configurable to,” “operable/operative to,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Those skilled in the art will recognize that “configured to” can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise. 
     The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” refers to the portion closest to the clinician and the term “distal” refers 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. 
     Those skilled in the art will recognize that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. 
     In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.” 
     With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flow diagrams are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise. 
     It is worthy to note that any reference to “one aspect,” “an aspect,” “an exemplification,” “one exemplification,” and the like means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, appearances of the phrases “in one aspect,” “in an aspect,” “in an exemplification,” and “in one exemplification” in various places throughout the specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more aspects. 
     In this specification, unless otherwise indicated, terms “about” or “approximately” as used in the present disclosure, unless otherwise specified, means an acceptable error for a particular value as determined by one of ordinary skill in the art, which depends in part on how the value is measured or determined. In certain embodiments, the term “about” or “approximately” means within 1, 2, 3, or 4 standard deviations. In certain embodiments, the term “about” or “approximately” means within 50%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, or 0.05% of a given value or range. 
     In this specification, unless otherwise indicated, all numerical parameters are to be understood as being prefaced and modified in all instances by the term “about,” in which the numerical parameters possess the inherent variability characteristic of the underlying measurement techniques used to determine the numerical value of the parameter. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter described herein should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. 
     Any numerical range recited herein includes all sub-ranges subsumed within the recited range. For example, a range of “1 to 10” includes all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10. Also, all ranges recited herein are inclusive of the end points of the recited ranges. For example, a range of “1 to 10” includes the end points 1 and 10. Any maximum numerical limitation recited in this specification is intended to include all lower numerical limitations subsumed therein, and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited. All such ranges are inherently described in this specification. 
     Any patent application, patent, non-patent publication, or other disclosure material referred to in this specification and/or listed in any Application Data Sheet is incorporated by reference herein, to the extent that the incorporated materials is not inconsistent herewith. 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. 
     In summary, numerous benefits have been described which result from employing the concepts described herein. The foregoing description of the one or more forms has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more forms were chosen and described in order to illustrate principles and practical application to thereby enable one of ordinary skill in the art to utilize the various forms and with various modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope.