Patent Publication Number: US-2019183502-A1

Title: Systems and methods of controlling a clamping member

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. 
     While several devices have been made and used, it is believed that no one prior to the inventors has made or used the device described in the appended claims. 
     SUMMARY 
     In one aspect, a surgical instrument comprising: a motor; a current sensor configured to sense a current drawn by the motor; and a control circuit coupled to the motor and the current sensor, the control circuit configured to: detect a position of a clamping member drivable by the motor between a first position and a second position, wherein the clamping member is configured to: transition an end effector to a closed position as the clamping member moves from the first position to the second position; and deploy a plurality of staples from a cartridge positioned in the end effector after the end effector is in the closed position as the clamping member moves to the second position; wherein the control circuit is further configured to: detect whether the current drawn by the motor exceeds a threshold via the current sensor; and upon detecting that the current drawn by the motor exceeds the threshold, control the motor to change a speed at which the clamping member is driven. 
     In another aspect, a surgical instrument comprising: a motor; a current sensor configured to sense a current drawn by the motor; and a control circuit coupled to the motor and the current sensor, the control circuit configured to: detect a position of a clamping member drivable by the motor between a first position and a second position, wherein the clamping member is configured to: transition an end effector to a closed position as the clamping member moves from the first position to the second position; and deploy a plurality of staples from a cartridge positioned in the end effector after the end effector is in the closed position as the clamping member moves to the second position; wherein the control circuit is further configured to: control the motor to change a speed at which the clamping member is driven at a defined position between the first position and the second position; and detect the defined position according to the current drawn by the motor via the current sensor. 
    
    
     
       FIGURES 
       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 an electromechanical surgical system; 
         FIG. 2  is a perspective view of a distal end of an electromechanical surgical instrument portion of the surgical system of  FIG. 1 ; 
         FIG. 3  is an exploded assembly view of an outer shell feature and the electromechanical surgical instrument of  FIG. 2 ; 
         FIG. 4  is a rear perspective view of a portion of the electromechanical surgical instrument of  FIG. 2 ; 
         FIG. 5  is a partial exploded assembly view of a portion of an adapter and the electromechanical surgical instrument of the surgical system of  FIG. 1 ; 
         FIG. 6  is an exploded assembly view of a portion of the adapter of  FIG. 5 ; 
         FIG. 7  is a cross-sectional perspective view of a portion of an articulation assembly of an adapter; 
         FIG. 8  is a perspective view of the articulation assembly of  FIG. 7 ; 
         FIG. 9  is another perspective view of the articulation assembly of  FIG. 8 ; 
         FIG. 10  is an exploded assembly view of a loading unit employed in the electromechanical surgical system of  FIG. 1 ; 
         FIG. 11  is a perspective view of an alternative adapter embodiment; 
         FIG. 12  is a side elevational view of a portion of a loading unit of the adapter of  FIG. 11  with the jaws thereof in an open position; 
         FIG. 13  is another side elevational view of a portion of the loading unit of  FIG. 11  with portions thereof shown in cross-section and the jaws thereof in a closed position; 
         FIG. 14  is a bottom view of a portion of the loading unit of  FIG. 13  with portions thereof shown in cross-section; 
         FIG. 15  is a perspective view of a portion of the loading unit of  FIG. 15  with a portion of the outer tube shown in phantom lines; 
         FIG. 16  is a schematic diagram of a circuit for controlling a motor of a surgical instrument; 
         FIG. 17  is a schematic diagram of a circuit for controlling a motor of a surgical instrument; 
         FIG. 18  is a schematic diagram of a position sensor of a surgical instrument; 
         FIG. 19  is a logic flow diagram of a process for controlling a speed of a clamping member during a firing stroke; 
         FIG. 20  is a logic flow diagram of a process for detecting a defined position according to motor current; 
         FIG. 21  is a graph of various clamping member firing strokes executed per the logic depicted in  FIGS. 19 and 20 ; 
         FIG. 22  is an exploded view of an anvil including a slot stop member; 
         FIG. 23  is a partial cutaway view of an anvil including a slot stop member; 
         FIG. 24  is a sectional view of an anvil including a slot stop member; 
         FIG. 25  is a side elevational view of an anvil including a slot stop member; 
         FIG. 26  is a longitudinal sectional view of an end effector and a drive assembly including a stop member, with the clamping member in a proximal position; 
         FIG. 27  is a longitudinal sectional view of an end effector and a drive assembly including a stop member, with the clamping member in a distal position; 
         FIG. 28  is a longitudinal sectional view of an end effector including a stop member located distally in the elongated slot, with the clamping member in a proximal position; 
         FIG. 29  is a longitudinal sectional view of an end effector including a stop member located distally in the elongated slot, with the clamping member in a distal position; and 
         FIG. 30  is a cross-sectional view of the adapter. 
     
    
    
     DESCRIPTION 
     Applicant of the present application owns the following U.S. Patent Applications that were filed on even date herewith and which are each herein incorporated by reference in their respective entireties:
     U.S. patent application Ser. No. ______, entitled SEALED ADAPTERS FOR USE WITH ELECTROMECHANICAL SURGICAL INSTRUMENTS; Attorney Docket No. END8286USNP/170227;   U.S. patent application Ser. No. ______, entitled END EFFECTORS WITH POSITIVE JAW OPENING FEATURES FOR USE WITH ADAPTERS FOR ELECTROMECHANICAL SURGICAL INSTRUMENTS; Attorney Docket No. END8277USNP/170219;   U.S. patent application Ser. No. ______, entitled SURGICAL END EFFECTORS WITH CLAMPING ASSEMBLIES CONFIGURED TO INCREASE JAW APERTURE RANGES; Attorney Docket No. END8278USNP/170220;   U.S. patent application Ser. No. ______, entitled SURGICAL END EFFECTORS WITH PIVOTAL JAWS CONFIGURED TO TOUCH AT THEIR RESPECTIVE DISTAL ENDS WHEN FULLY CLOSED; Attorney Docket No. END8283USNP/170223;   U.S. patent application Ser. No. ______, entitled SURGICAL END EFFECTORS WITH JAW STIFFENER ARRANGEMENTS CONFIGURED TO PERMIT MONITORING OF FIRING MEMBER; Attorney Docket No. END8282USNP/170221;   U.S. patent application Ser. No. ______, entitled ADAPTERS WITH END EFFECTOR POSITION SENSING AND CONTROL ARRANGEMENTS FOR USE IN CONNECTION WITH ELECTROMECHANICAL SURGICAL INSTRUMENTS; Attorney Docket No. END8281USNP/170228;   U.S. patent application Ser. No. ______, entitled DYNAMIC CLAMPING ASSEMBLIES WITH IMPROVED WEAR CHARACTERISTICS FOR USE IN CONNECTION WITH ELECTROMECHANICAL SURGICAL INSTRUMENTS; Attorney Docket No. END8279USNP/170222;   U.S. patent application Ser. No. ______, entitled ADAPTERS WITH FIRING STROKE SENSING ARRANGEMENTS FOR USE IN CONNECTION WITH ELECTROMECHANICAL SURGICAL INSTRUMENTS; Attorney Docket No. END8287USNP/170229;   U.S. patent application Ser. No. ______, entitled ADAPTERS WITH CONTROL SYSTEMS FOR CONTROLLING MULTIPLE MOTORS OF AN ELECTRICAL MECHANICAL SURGICAL INSTRUMENT; Attorney Docket No. END8284USNP/170224;   U.S. patent application Ser. No. ______, entitled HANDHELD ELECTROMECHANICAL SURGICAL INSTRUMENTS WITH IMPROVED MOTOR CONTROL ARRANGEMENTS FOR POSITIONING COMPONENTS OF AN ADAPTER COUPLED THERETO; Attorney Docket No. END8285USNP/170255;   U.S. patent application Ser. No. ______, entitled SYSTEMS AND METHODS OF CONTROLLING A CLAMPING MEMBER FIRING RATE OF A SURGICAL INSTRUMENT; Attorney Docket No. END8280USNP/170226; and   U.S. patent application Ser. No. ______, entitled METHODS OF OPERATING SURGICAL END EFFECTORS; Attorney Docket No. END8298USNP/170218M.   

     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. 
     The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a surgical system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, an element of a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. 
     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. 
     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. 
       FIG. 1  depicts a motor-driven (electromechanical) surgical system  1  that may be used to perform a variety of different surgical procedures. As can be seen in that Figure, one example of the surgical system  1  includes a powered handheld electromechanical surgical instrument  100  that is configured for selective attachment thereto of a plurality of different surgical tool implements (referred to herein as “adapters”) that are each configured for actuation and manipulation by the powered handheld electromechanical surgical instrument. As illustrated in  FIG. 1 , the handheld surgical instrument  100  is configured for selective connection with an adapter  200 , and, in turn, adapter  200  is configured for selective connection with end effectors that comprise a single use loading unit (“SULU”) or a disposable loading unit (“DLU”) or a multiple use loading unit (“MULU”). In another surgical system embodiment, various forms of adapter  200  may also be effectively employed with a tool drive assembly of a robotically controlled or automated surgical system. For example, the surgical tool 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. 
     As illustrated in  FIGS. 1 and 2 , surgical instrument  100  includes a power-pack  101  and an outer shell housing  10  that is configured to selectively receive and substantially encase the power-pack  101 . The power pack  101  may also be referred to herein as handle assembly  101 . One form of surgical instrument  100 , for example, is disclosed in International Publication No. WO 2016/057225 A1, International Application No. PCT/US2015/051837, entitled HANDHELD ELECTROMECHANICAL SURGICAL SYSTEM, the entire disclosure of which is hereby incorporated by reference herein. Various features of surgical instrument  100  will not be disclosed herein beyond what is necessary to understand the various features of the inventions disclosed herein with it being understood that further details may be gleaned from reference to WO 2016/057225 and other references incorporated by reference herein. 
     As illustrated in  FIG. 3 , outer shell housing  10  includes a distal half-section  10   a  and a proximal half-section  10   b  that is pivotably connected to distal half-section  10   a  by a hinge  16  located along an upper edge of distal half-section  10   a  and proximal half-section  10   b.  When joined, distal and proximal half-sections  10   a,    10   b  define a shell cavity  10   c  therein in which the power-pack  101  is selectively situated. Each of distal and proximal half-sections  10   a,    10   b  includes a respective upper shell portion  12   a,    12   b,  and a respective lower shell portion  14   a,    14   b.  Lower shell portions  14   a,    14   b  define a snap closure feature  18  for selectively securing the lower shell portions  14   a,    14   b  to one another and for maintaining shell housing  10  in a closed condition. Distal half-section  10   a  of shell housing  10  defines a connecting portion  20  that is configured to accept a corresponding drive coupling assembly  210  of adapter  200  (see  FIG. 5 ). Specifically, distal half-section  10   a  of shell housing  10  has a recess that receives a portion of drive coupling assembly  210  of adapter  200  when adapter  200  is mated to surgical instrument  100 . 
     Connecting portion  20  of distal half-section  10   a  defines a pair of axially extending guide rails  21 a,  21 b that project radially inward from inner side surfaces thereof as shown in  FIG. 5 . Guide rails  21 a,  21 b assist in rotationally orienting adapter  200  relative to surgical instrument  100  when adapter  200  is mated to surgical instrument  100 . Connecting portion  20  of distal half-section  10   a  defines three apertures  22   a,    22   b,    22   c  that are formed in a distally facing surface thereof and which are arranged in a common plane or line with one another. Connecting portion  20  of distal half-section  10   a  also defines an elongate slot  24  also formed in the distally facing surface thereof. Connecting portion  20  of distal half-section  10   a  further defines a female connecting feature  26  (see  FIG. 2 ) formed in a surface thereof. Female connecting feature  26  selectively engages with a male connecting feature of adapter  200 . 
     Distal half-section  10   a  of shell housing  10  supports a distal facing toggle control button  30 . The toggle control button  30  is capable of being actuated in a left, right, up and down direction upon application of a corresponding force thereto or a depressive force thereto. Distal half-section  10   a  of shell housing  10  supports a right-side pair of control buttons  32   a,    32   b  (see  FIG. 3 ); and a left-side pair of control button  34   a,    34   b  (see  FIG. 2 ). The right-side control buttons  32   a,    32   b  and the left-side control buttons  34   a,    34   b  are capable of being actuated upon application of a corresponding force thereto or a depressive force thereto. Proximal half-section  10   b  of shell housing  10  supports a right-side control button  36   a  (see  FIG. 3 ) and a left-side control button  36   b  (see  FIG. 2 ). Right-side control button  36   a  and left-side control button  36   b  are capable of being actuated upon application of a corresponding force thereto or a depressive force thereto. 
     Shell housing  10  includes a sterile barrier plate assembly  60  selectively supported in distal half-section  10   a.  Specifically, the sterile barrier plate assembly  60  is disposed behind connecting portion  20  of distal half-section  10   a  and within shell cavity  10   c  of shell housing  10 . The plate assembly  60  includes a plate  62  rotatably supporting three coupling shafts  64   a,    64   b,    64   c  (see  FIGS. 3 and 5 ). Each coupling shaft  64   a,    64   b,    64   c  extends from opposed sides of plate  62  and has a tri-lobe transverse cross-sectional profile. Each coupling shaft  64   a,    64   b,    64   c  extends through the respective apertures  22   a,    22   b,    22   c  of connecting portion  20  of distal half-section  10   a  when the sterile barrier plate assembly  60  is disposed within shell cavity  10   c  of shell housing  10 . The plate assembly  60  further includes an electrical pass-through connector  66  supported on plate  62 . Pass-through connector  66  extends from opposed sides of plate  62 . Pass-through connector  66  defines a plurality of contact paths each including an electrical conduit for extending an electrical connection across plate  62 . When the plate assembly  60  is disposed within shell cavity  10   c  of shell housing  10 , distal ends of coupling shaft  64   a,    64   b,    64   c  and a distal end of pass-through connector  66  are disposed or situated within connecting portion  20  of distal half-section  10   a  of shell housing  10 , and are configured to electrically and/or mechanically engage respective corresponding features of adapter  200 . 
     Referring to  FIGS. 3 and 4 , the power-pack or the handle assembly  101  includes an inner handle housing  110  having a lower housing portion  104  and an upper housing portion  108  extending from and/or supported on lower housing portion  104 . Lower housing portion  104  and upper housing portion  108  are separated into a distal half section  110   a  and a proximal half-section  110   b  connectable to distal half-section  110   a  by a plurality of fasteners. When joined, distal and proximal half-sections  110   a,    110   b  define the inner handle housing  110  having an inner housing cavity  110   c  therein in which a power-pack core assembly  106  is situated. Power-pack core assembly  106  is configured to control the various operations of surgical instrument  100 . 
     Distal half-section  110   a  of inner handle housing  110  supports a distal toggle control interface  130  that is in operative registration with the distal toggle control button  30  of shell housing  10 . In use, when the power-pack  101  is disposed within shell housing  10 , actuation of the toggle control button  30  exerts a force on toggle control interface  130 . Distal half-section  110   a  of inner handle housing  110  also supports a right-side pair of control interfaces (not shown), and a left-side pair of control interfaces  132   a,    132   b.  In use, when the power-pack  101  is disposed within shell housing  10 , actuation of one of the right-side pair of control buttons or the left-side pair of control button of distal half-section  10   a  of shell housing  10  exerts a force on a respective one of the right-side pair of control interfaces  132   a,    132   b  or the left-side pair of control interfaces  132   a,    132   b  of distal half-section  110   a  of inner handle housing  110 . 
     With reference to  FIGS. 1-5 , inner handle housing  110  provides a housing in which power-pack core assembly  106  is situated. Power-pack core assembly  106  includes a battery circuit  140 , a controller circuit board  142  and a rechargeable battery  144  configured to supply power to any of the electrical components of surgical instrument  100 . Controller circuit board  142  includes a motor controller circuit board  142   a,  a main controller circuit board  142   b,  and a first ribbon cable  142   c  interconnecting motor controller circuit board  142   a  and main controller circuit board  142   b.  Power-pack core assembly  106  further includes a display screen  146  supported on main controller circuit board  142   b.  Display screen  146  is visible through a clear or transparent window  110 d (see  FIG. 3 ) provided in proximal half-section  110   b  of inner handle housing  110 . It is contemplated that at least a portion of inner handle housing  110  may be fabricated from a transparent rigid plastic or the like. It is further contemplated that shell housing  10  may either include a window formed therein (in visual registration with display screen  146  and with window  110 d of proximal half-section  110   b  of inner handle housing  110 , and/or shell housing  10  may be fabricated from a transparent rigid plastic or the like. 
     Power-pack core assembly  106  further includes a first motor  152 , a second motor  154 , and a third motor  156  that are supported by motor bracket  148  and are each electrically connected to controller circuit board  142  and battery  144 . Motors  152 ,  154 ,  156  are disposed between motor controller circuit board  142   a  and main controller circuit board  142   b.  Each motor  152 ,  154 ,  156  includes a respective motor shaft  152   a,    154   a,    156   a  extending therefrom. Each motor shaft  152   a,    154   a,    156   a  has a tri-lobe transverse cross-sectional profile for transmitting rotative forces or torque. Each motor  152 ,  154 ,  156  is controlled by a respective motor controller. Rotation of motor shafts  152   a,    154   a,    156   a  by respective motors  152 ,  154 ,  156  function to drive shafts and/or gear components of adapter  200  in order to perform the various operations of surgical instrument  100 . In particular, motors  152 ,  154 ,  156  of power-pack core assembly  106  are configured to drive shafts and/or gear components of adapter  200 . 
     As illustrated in  FIGS. 1 and 5 , surgical instrument  100  is configured for selective connection with adapter  200 , and, in turn, adapter  200  is configured for selective connection with end effector  500 . Adapter  200  includes an outer knob housing  202  and an outer tube  206  that extends from a distal end of knob housing  202 . Knob housing  202  and outer tube  206  are configured and dimensioned to house the components of adapter assembly  200 . Outer tube  206  is dimensioned for endoscopic insertion, in particular, that outer tube is passable through a typical trocar port, cannula or the like. Knob housing  202  is dimensioned to not enter the trocar port, cannula of the like. Knob housing  202  is configured and adapted to connect to connecting portion  20  of the outer shell housing  10  of surgical instrument  100 . 
     Adapter  200  is configured to convert a rotation of either of first or second coupling shafts  64   a,    64   b  of surgical instrument  100  into axial translation useful for operating a drive assembly  540  and an articulation link  560  of end effector  500 , as illustrated in  FIG. 10  and as will be described in greater detail below. As illustrated in  FIG. 6 , adapter  200  includes the proximal inner housing assembly  204  that rotatably supports a first rotatable proximal drive shaft  212 , a second rotatable proximal drive shaft  214 , and a third rotatable proximal drive shaft  216  therein. Each proximal drive shaft  212 ,  214 ,  216  functions as a rotation receiving member to receive rotational forces from respective coupling shafts  64   a,    64   b  and  64   c  of surgical instrument  100 . In addition, the drive coupling assembly  210  of adapter  200  is also configured to rotatably support first, second and third connector sleeves  218 ,  220  and  222 , respectively, arranged in a common plane or line with one another. Each connector sleeve  218 ,  220 ,  222  is configured to mate with respective first, second and third coupling shafts  64   a,    64   b,    64   c  of surgical instrument  100 , as described above. Each connector sleeves  218 ,  222 ,  220  is further configured to mate with a proximal end of respective first, second, and third proximal drive shafts  212 ,  214 ,  216  of adapter  200 . 
     Drive coupling assembly  210  of adapter  200  also includes a first, a second, and a third biasing member  224 ,  226 , and  228  disposed distally of respective first, second, and third connector sleeves  218 ,  220 ,  222 . Each biasing members  224 ,  226 , and  228  is disposed about respective first, second, and third rotatable proximal drive shaft  212 ,  214 , and  216 . Biasing members  224 ,  226 , and  228  act on respective connector sleeves  218 ,  222 , and  220  to help maintain connector sleeves  218 ,  222 . and  220  engaged with the distal end of respective coupling shafts  64   a,    64   b,  and  64   c  of surgical instrument  100  when adapter  200  is connected to surgical instrument  100 . 
     Also in the illustrated arrangement, adapter  200  includes first, second, and third drive converting assemblies  240 ,  250 ,  260 , respectively, that are each disposed within inner housing assembly  204  and outer tube  206 . Each drive converting assembly  240 ,  250 ,  260  is configured and adapted to transmit or convert a rotation of a first, second, and third coupling shafts  64   a,    64   b,  and  64   c  of surgical instrument  100  into axial translation of an articulation driver or bar  258  of adapter  200 , to effectuate articulation of end effector  500 ; a rotation of a ring gear  266  of adapter  200 , to effectuate rotation of adapter  200 ; or axial translation of a distal drive member  248  of adapter  200  to effectuate closing, opening, and firing of end effector  500 . 
     Still referring to  FIG. 6 , first force/rotation transmitting/converting assembly  240  includes first rotatable proximal drive shaft  212 , which, as described above, is rotatably supported within inner housing assembly  204 . First rotatable proximal drive shaft  212  includes a non-circular or shaped proximal end portion configured for connection with first connector sleeve  218  which is connected to respective first coupling shaft  64   a  of surgical instrument  100 . First rotatable proximal drive shaft  212  includes a threaded distal end portion  212   b.  First force/rotation transmitting/converting assembly  240  further includes a drive coupling nut  244  that threadably engages the threaded distal end portion  212   b  of first rotatable proximal drive shaft  212 , and which is slidably disposed within outer tube  206 . Drive coupling nut  244  is slidably keyed within proximal core tube portion of outer tube  206  so as to be prevented from rotation as first rotatable proximal drive shaft  212  is rotated. In this manner, as the first rotatable proximal drive shaft  212  is rotated, drive coupling nut  244  is translated along threaded distal end portion  212   b  of first rotatable proximal drive shaft  212  and, in turn, through and/or along outer tube  206 . 
     First force/rotation transmitting/converting assembly  240  further includes a distal drive member  248  that is mechanically engaged with drive coupling nut  244 , such that axial movement of drive coupling nut  244  results in a corresponding amount of axial movement of distal drive member  248 . The distal end portion of distal drive member  248  supports a connection member  247  configured and dimensioned for selective engagement with an engagement member  546  of a drive assembly  540  of end effector  500  ( FIG. 10 ). Drive coupling nut  244  and/or distal drive member  248  function as a force transmitting member to components of end effector  500 . In operation, as first rotatable proximal drive shaft  212  is rotated, as a result of the rotation of first coupling shaft  64   a  of surgical instrument  100 , drive coupling nut  244  is translated axially along first rotatable proximal drive shaft  212 . As drive coupling nut  244  is translated axially along first rotatable proximal drive shaft  212 , distal drive member  248  is translated axially relative to outer tube  206 . As distal drive member  248  is translated axially, with connection member  247  connected thereto and engaged with a hollow drive member  548  attached to drive assembly  540  of end effector  500  ( FIG. 10 ), distal drive member  248  causes concomitant axial translation of drive assembly  540  of end effector  500  to effectuate a closure of a tool assembly portion  600  of the end effector  500  and a firing of various components within the tool assembly. 
     Still referring to  FIG. 6 , second drive converting assembly  250  of adapter  200  includes second proximal drive shaft  214  that is rotatably supported within inner housing assembly  204 . Second rotatable proximal drive shaft  214  includes a non-circular or shaped proximal end portion configured for connection with second coupling shaft  64   c  of surgical instrument  100 . Second rotatable proximal drive shaft  214  further includes a threaded distal end portion  214   a  configured to threadably engage an articulation bearing housing  253  of an articulation bearing assembly  252 . Referring to  FIGS. 6-9 , the articulation bearing housing  253  supports an articulation bearing  255  that has an inner race  257  that is independently rotatable relative to an outer race  259 . Articulation bearing housing  253  has a non-circular outer profile, for example tear-dropped shaped, that is slidably and non-rotatably disposed within a complementary bore (not shown) of inner housing hub  204   a.  Second drive converting assembly  250  of adapter  200  further includes articulation bar  258  that has a proximal portion that is secured to inner race  257  of articulation bearing  255 . A distal portion of articulation bar  258  includes a slot  258 a therein, which is configured to accept a hook  562  the articulation link  560  ( FIG. 10 ) of end effector  500 . Articulation bar  258  functions as a force transmitting member to components of end effector  500 . In the illustrated arrangement and as further discussed in WO 2016/057225 A1, articulation bearing assembly  252  is both rotatable and longitudinally translatable and is configured to permit free, unimpeded rotational movement of end effector  500  when its first and second jaw members  610 ,  700  are in an approximated position and/or when jaw members  610 ,  700  are articulated. 
     In operation, as second proximal drive shaft  214  is rotated, the articulation bearing assembly  252  is axially translated along threaded distal end portion  214   a  of second proximal drive shaft  214 , which in turn, causes articulation bar  258  to be axially translated relative to outer tube  206 . As articulation bar  258  is translated axially, articulation bar  258 , being coupled to articulation link  560  of end effector  500 , causes concomitant axial translation of articulation link  560  of end effector  500  to effectuate an articulation of tool assembly  600 . Articulation bar  258  is secured to inner race  257  of articulation bearing  253  and is thus free to rotate about the longitudinal axis relative to outer race  259  of articulation bearing  253 . 
     As illustrated in  FIG. 6 , adapter  200  includes a third drive converting assembly  260  that is supported in inner housing assembly  204 . Third drive converting assembly  260  includes rotation ring gear  266  that is fixedly supported in and connected to outer knob housing  202 . Ring gear  266  defines an internal array of gear teeth  266   a  and includes a pair of diametrically opposed, radially extending protrusions  266   b.  Protrusions  266   b  are configured to be disposed within recesses defined in outer knob housing  202 , such that rotation of ring gear  266  results in rotation of outer knob housing  202 , and vice a versa. Third drive converting assembly  260  further includes third rotatable proximal drive shaft  216  which, as described above, is rotatably supported within inner housing assembly  204 . Third rotatable proximal drive shaft  216  includes a non-circular or shaped proximal end portion that is configured for connection with third connector  220 . Third rotatable proximal drive shaft  216  includes a spur gear  216  keyed to a distal end thereof. A reversing spur gear  264  inter-engages spur gear  216   a  of third rotatable proximal drive shaft  216  to gear teeth  266   a  of ring gear  266 . In operation, as third rotatable proximal drive shaft  216  is rotated, due to a rotation of the third coupling shaft  64   b  of surgical instrument  100 , spur gear  216   a  of third rotatable proximal drive shaft  216  engages reversing gear  264  causing reversing gear  264  to rotate. As reversing gear  264  rotates, ring gear  266  also rotates thereby causing outer knob housing  202  to rotate. Rotation of the outer knob housing  202  causes the outer tube  206  to rotate about longitudinal axis of adapter  200 . As outer tube  206  is rotated, end effector  500  that is connected to a distal end portion of adapter  200 , is also rotated about a longitudinal axis of adapter  200 . 
     Adapter  200  further includes an attachment/detachment button  272  ( FIG. 5 ) that is supported on a stem  273  ( FIG. 6 ) that projects from drive coupling assembly  210  of adapter  200 . The attachment/detachment button  272  is biased by a biasing member (not shown) that is disposed within or around stem  273 , to an un-actuated condition. Button  272  includes a lip or ledge that is configured to snap behind a corresponding lip or ledge of connecting portion  20  of the surgical instrument  100 . As also discussed in WO 2016/057225 A1, the adapter  200  may further include a lock mechanism  280  for fixing the axial position of distal drive member  248 . As can be seen in  FIG. 21 , for example, lock mechanism  280  includes a button  282  that is slidably supported on outer knob housing  202 . Lock button  282  is connected to an actuation bar (not shown) that extends longitudinally through outer tube  206 . Actuation bar moves upon a movement of lock button  282 . In operation, in order to lock the position and/or orientation of distal drive member  248 , a user moves lock button  282  from a distal position to a proximal position, thereby causing the lock out (not shown) to move proximally such that a distal face of the lock out moves out of contact with camming member  288 , which causes camming member  288  to cam into recess  249  of distal drive member  248 . In this manner, distal drive member  248  is prevented from distal and/or proximal movement. When lock button  282  is moved from the proximal position to the distal position, the distal end of actuation bar moves distally into the lock out (not shown), against the bias of a biasing member (not shown), to force camming member  288  out of recess  249 , thereby allowing unimpeded axial translation and radial movement of distal drive member  248 . 
     Returning again to  FIG. 6 , adapter  200  includes an electrical assembly  290  supported on and in outer knob housing  202  and inner housing assembly  204 . Electrical assembly  290  includes a plurality of electrical contact blades  292 , supported on a circuit board  294 , for electrical connection to pass-through connector of plate assembly of shell housing  10  of surgical instrument  100 . Electrical assembly  290  serves to allow for calibration and communication information (i.e., life-cycle information, system information, force information) to pass to the circuit board of surgical instrument  100  via an electrical receptacle portion of the power-pack core assembly  106  of surgical instrument  100 . Electrical assembly  290  further includes a strain gauge  296  that is electrically connected to circuit board  294 . Strain gauge  296  is mounted within the inner housing assembly  204  to restrict rotation of the strain gauge  296  relative thereto. First rotatable proximal drive shaft  212  extends through strain gauge  296  to enable the strain gauge  296  to provide a closed-loop feedback to a firing/clamping load exhibited by first rotatable proximal drive shaft  212 . Electrical assembly  290  also includes a slip ring  298  that is non-rotatably and slidably disposed along drive coupling nut  244  of outer tube  206 . Slip ring  298  is in electrical connection with circuit board  294  and serves to permit rotation of first rotatable proximal drive shaft  212  and axial translation of drive coupling nut  244  while still maintaining electrical contact of slip ring  298  with at least another electrical component within adapter  200 , and while permitting the other electrical components to rotate about first rotatable proximal drive shaft  212  and drive coupling nut  244 . 
     Still referring to  FIG. 6 , inner housing assembly  204  includes a hub  205  that has a distally oriented annular wall  207  that defines a substantially circular outer profile. Hub  205  includes a substantially tear-drop shaped inner recess or bore that is shaped and dimensioned to slidably receive articulation bearing assembly  252  therewithin. Inner housing assembly  204  further includes a ring plate  254  that is secured to a distal face of distally oriented annular wall  207  of hub  204   a.  Ring plate  254  defines an aperture  254   a  therethrough that is sized and formed therein so as to be aligned with second proximal drive shaft  214  and to rotatably receive a distal tip thereof. In this manner, the distal tip of the second proximal drive shaft  214  is supported and prevented from moving radially away from a longitudinal rotational axis of second proximal drive shaft  214  as second proximal drive shaft  214  is rotated to axially translate articulation bearing assembly  252 . 
     Turning next to  FIG. 10 , in one example, the end effector  500  may be configured for a single use (“disposable loading unit—DLU”) and be similar to those DLU&#39;s disclosed in U.S. Patent Application Publication No. US 2010/0301097, entitled LOADING UNIT HAVING DRIVE ASSEMBLY LOCKING MECHANISM, U.S. Patent Application Publication No. US 2012/0217284, entitled LOCKING MECHANISM FOR USE WITH LOADING UNITS, and U.S. Patent Application Publication No. US 2015/0374371, entitled ADAPTER ASSEMBLIES FOR INTERCONNECTING SURGICAL LOADING UNITS AND HANDLE ASSEMBLIES, the entire disclosures of each such references being hereby incorporated by reference herein. It is also contemplated that the end effector  500  may be configured for multiple uses (MULU) such as those end effectors disclosed in US Patent Application Publication No. US 2017/0095250, entitled MULTI-USE LOADING UNIT, the entire disclosure of which is hereby incorporated by reference herein. 
     The depicted surgical instrument  100  fires staples, but it may be adapted to fire any other suitable fastener such as clips and two-part fasteners. In the illustrated arrangement, the end effector  500  comprises a loading unit  510 . The loading unit  510  comprises a proximal body portion  520  and a tool assembly  600 . Tool assembly  600  includes a pair of jaw members including a first jaw member  610  that comprises an anvil assembly  612  and a second jaw member  700  that comprises a cartridge assembly  701 . One jaw member is pivotal in relation to the other to enable the clamping of tissue between the jaw members. The cartridge assembly  701  is movable in relation to anvil assembly  612  and is movable between an open or unclamped position and a closed or approximated position. However, the anvil assembly  612 , or both the cartridge assembly  701  and the anvil assembly  612 , can be movable. 
     The cartridge assembly  701  has a cartridge body  702  and in some instances a support plate  710  that are attached to a channel  720  by a snap-fit connection, a detent, latch, or by another type of connection. The cartridge assembly  701  includes fasteners or staples  704  that are movably supported in a plurality of laterally spaced staple retention slots  706 , which are configured as openings in a tissue contacting surface  708 . Each slot  706  is configured to receive a fastener or staple therein. Cartridge body  702  also defines a plurality of cam wedge slots which accommodate staple pushers  709  and which are open on the bottom (i.e., away from tissue-contacting surface) to allow an actuation sled  712  to pass longitudinally therethrough. The cartridge assembly  701  is removable from channel  720  after the staples have been fired from cartridge body  702 . Another removable cartridge assembly is capable of being loaded onto channel  720 , such that surgical instrument  100  can be actuated again to fire additional fasteners or staples. Further details concerning the cartridge assembly may be found, for example, in US Patent Application Publication No. US2017/0095250 as well as various other references that have been incorporated by reference herein. 
     Cartridge assembly  701  is pivotal in relation to anvil assembly  612  and is movable between an open or unclamped position and a closed or clamped position for insertion through a cannula of a trocar. Proximal body portion  520  includes at least a drive assembly  540  and an articulation link  560 . In one arrangement, drive assembly  540  includes a flexible drive beam  542  that has a distal end  544  and a proximal engagement section  546 . A proximal end of the engagement section  546  includes diametrically opposed inwardly extending fingers  547  that engage a hollow drive member  548  to fixedly secure drive member  548  to the proximal end of beam  542 . Drive member  548  defines a proximal porthole which receives connection member  247  of drive tube  246  of first drive converting assembly  240  of adapter  200  when the end effector  500  is attached to the distal end of the adapter  200 . 
     End effector  500  further includes a housing assembly  530  that comprises an outer housing  532  and an inner housing  534  that is disposed within outer housing  532 . First and second lugs  536  are each disposed on an outer surface of a proximal end  533  of outer housing  532  and are configured to operably engage the distal end of the adapter  200  as discussed in further detail in WO 2016/057225 A1. 
     With reference to  FIG. 10 , for example, anvil assembly  612  includes an anvil cover  630  and an anvil plate  620 , which includes a plurality of staple forming depressions. Anvil plate  620  is secured to an underside of anvil cover  630 . When tool assembly  600  is in the approximated position, staple forming depressions are positioned in juxtaposed alignment with staple receiving slots of the cartridge assembly  701 . 
     The tool assembly  600  includes a mounting assembly  800  that comprises an upper mounting portion  810  and a lower mounting portion  812 . A mounting tail  632  protrudes proximally from a proximal end  631  of the anvil cover  630 . A centrally-located pivot member  814  extends from each upper and lower mounting portions  810  and  812  through openings  822  that are formed in coupling members  820 . In at least one arrangement, the pivot member  814  of the upper mounting portion  810  also extends through an opening  634  in the mounting tail  632  as well. Coupling members  820  each include an interlocking proximal portion  824  that is configured to be received in corresponding grooves formed in distal ends of the outer housing  532  and inner housing  534 . Proximal body portion  520  of end effector  500  includes articulation link  560  that has a hooked proximal end  562 . The articulation link  560  is dimensioned to be slidably positioned within a slot in the inner housing. A pair of H-block assemblies  830  are positioned adjacent the distal end of the outer housing  532  and adjacent the distal end  544  of axial drive assembly  540  to prevent outward buckling and bulging of the flexible drive beam  542  during articulation and firing of surgical stapling apparatus  10 . Each H-block assembly  830  includes a flexible body  832  which includes a proximal end fixedly secured to the distal end of the outer housing  532  and a distal end that is fixedly secured to mounting assembly  800 . In one arrangement, a distal end  564  of the articulation link is pivotally pinned to the right H block assembly  830 . Axial movement of the articulation link  560  will cause the tool assembly to articulate relative to the body portion  520 . 
       FIGS. 11-15  illustrate an adapter  200 ′ that is substantially identical to adapter  200  described above, except for the differences noted below. As can be seen in  FIG. 11 , the adapter  200 ′ includes an outer tube  206  that has a proximal end portion  910  that has a first diameter “FD” and is mounted within the outer knob housing  202 . The proximal end portion  910  may be coupled to the inner housing assembly  204  or otherwise supported therein in the manners discussed in further detail in WO 2016/057225 A1 for example. The proximal end portion  910  extends proximally from a central tube portion  912  that has a second diameter “SD”. In the illustrated embodiment, an end effector  500  is coupled to a distal end  914  of a shaft assembly  203  or outer tube  206 . The outer tube  206  defines a longitudinal axis LA that extends between the proximal end portion  910  and the distal end  914  as can be seen in  FIG. 11 . As can be seen in  FIGS. 10 and 11 , an outer sleeve  570  of the proximal body portion  520  of the end effector  500  has a distal end portion  572  and a proximal end portion  574 . The proximal end portion  574  has a diameter SD′ that is approximately equal to the second diameter SD of the central tube portion  912 . The distal end portion  572  has a third diameter “TD”. In one arrangement, FD and TD are approximately equal and greater than SD. Other arrangements are contemplated wherein FD and TD are not equal, but each are greater than SD. However, it is preferable that for most cases FD and TD are dimensioned for endoscopic insertion through a typical trocar port, cannula or the like. In at least one arrangement ( FIG. 11 ), the outer sleeve  570  is formed with a flat or scalloped side  576  to facilitate improved access within the patient while effectively accommodating the various drive and articulation components of the adapter  200 ′. In addition, by providing the central tube portion  912  with a reduced diameter may afford the adapter  200 ′ with improved thoracic in-between rib access. 
     In at least one arrangement, channel  720 , which may be machined or made of sheet metal, includes a pair of proximal holes  722  ( FIG. 10 ) that are configured to align with a pair of corresponding holes  636  in the anvil cover  630  to receive corresponding pins or bosses  638  ( FIG. 12 ) to facilitate a pivotal relationship between anvil assembly  612  and cartridge assembly  701 . In the illustrated example, a dynamic clamping assembly  550  is attached to or formed at the distal end  544  of the flexible drive beam  542 . The dynamic clamping assembly  550  includes a vertical body portion  552  that has a tissue cutting surface  554  formed thereon or attached thereto. See  FIG. 10 , for example. An anvil engagement feature  556  is formed on one end of the body portion  552  and comprises an anvil engagement tab  557  that protrudes from each lateral side of the body portion  552 . Similarly, a channel engagement feature  558  is formed on the other end of the of the body portion  552  and comprises a channel engagement tab  559  that protrudes from each lateral side of the body portion  552 . See  FIG. 15 . 
     As indicated above, the anvil assembly  612  includes an anvil plate  620 . The anvil plate  620  includes an elongate slot  622  that is configured to accommodate the body portion  552  of the dynamic clamping assembly  550  as the dynamic clamping assembly  550  is axially advanced during the firing process. The elongate slot  622  is defined between two anvil plate ledges  624  that extend along each lateral side of the elongate slot  622 . See  FIG. 10 . As the dynamic clamping assembly  550  is distally advanced, the anvil engagement tabs  557  slidably engage the anvil plate ledges  624  to retain the anvil assembly  612  clamped onto the target tissue. Similarly, during the firing operation, the body portion  552  of the dynamic clamping assembly  550  extends through a central slot in the channel  720  and the channel engagement tabs  559  slidably engage channel ledges  725  extending along each side of the central channel slot to retain the cartridge assembly  701  clamped onto the target tissue. 
     Turning to  FIGS. 13 and 15 , the channel  720  defines a docking area generally designated as  730  that is configured to accommodate the dynamic clamping assembly  550  when it is in its proximal most position referred to herein as an unfired or starting position. In particular, the docking area  730  is partially defined by planar docking surfaces  732  that provides clearance between the channel engagement tabs  559  on the dynamic clamping assembly  550  to enable the cartridge assembly  701  to pivot to a fully opened position. A ramped or camming surface  726  extends from a distal end of each of the docking surfaces  732 . Ramped surface  726  is engaged by the dynamic clamping assembly  550  in order to move the anvil assembly  612  and the cartridge assembly  701  with respect to one another. Similar camming surface could be provided on the anvil assembly  612  in other embodiments. It is envisioned that ramped surfaces  726  may also facilitate the alignment and/or engagement between channel  720  and support plate  620  and/or cartridge body  702 . As the drive assembly  540  is distally advanced (fired), the channel engagement tabs  559  on the dynamic clamping assembly  550  engage the corresponding ramped surfaces  726  to apply a closing motion to the cartridge assembly  701  thus closing the cartridge assembly  701  and the anvil assembly  612 . Further distal translation of the dynamic clamping assembly  550  causes the actuation sled  712  to move distally through cartridge body  702 , which causes cam wedges  713  of actuation sled  712  to sequentially engage staple pushers  709  to move staple pushers  709  vertically within staple retention slots  706  and eject staples  704  into staple forming depressions of anvil plate  620 . Subsequent to the ejection of staples  704  from retention slots  706  (and into tissue), the cutting edge  554  of the dynamic clamping assembly  550  severs the stapled tissue as the tissue cutting edge  554  on the vertical body portion  552  of the dynamic clamping assembly  550  travels distally through a central slot  703  of cartridge body  702 . After staples  704  have been ejected from cartridge body  702  and a user wishes to use the same instrument  10  to fire additional staples  704  (or another type of fastener or knife), the user can remove the loading unit  510  from the adapter  200 ′ and replace it with another fresh or unspent loading unit. In an alternative arrangement, the user may simply remove the spent cartridge body  702  and replace it with a fresh unspent or unfired cartridge body  702 . 
     The surgical instrument  100  can include sensor assemblies for detecting various states and/or parameters associated with the operation of the surgical instrument  100 . A control circuit or processor can monitor these sensed states and/or parameters and then control the operation of the surgical instrument  100  accordingly. For example, the surgical instrument  100  can monitor the current drawn by the motor driving the first force/rotation transmitting/converting assembly  240  ( FIG. 6 ) in order to control the speed at which the clamping member  550  ( FIG. 10 ) is translated. As another example, the surgical instrument  100  can monitor the gap or distance between the jaw members or the anvil plate  620  ( FIG. 10 ) and the cartridge body  702  ( FIG. 10 ) when the end effector  500  is clamped in order to control the speed at which the clamping member  550  is driven thereafter. These and other sensor assemblies with corresponding logic executed by a control circuit or processor in conjunction with the sensor assemblies are described herebelow. 
       FIGS. 16 and 17  illustrate schematic diagrams a circuit  2000  for controlling a motor  2010  of a surgical instrument, according to various aspects of the present disclosure. In the depicted aspects, the circuit  2000  includes a switch  2002 , a first limit switch  2004  (e.g., a normally open switch), a second limit switch  2006  (e.g., a normally closed switch), a power source  2008 , and a motor  2010  (e.g., a motor that is configured to drive the first force/rotation transmitting/converting assembly  240 ). The circuit  2002  can further include a first relay  2012  (e.g., a single-pole double-throw relay), a second relay  2014  (e.g., a single-pole single-throw relay), a third relay  2016  (e.g., a double-pole double-throw relay), a current sensor  2018 , and a current detection module  2030 . In one aspect, the circuit  2000  can include a motor control circuit  2028  that is configured to sense the electrical current through the motor  2010  and then control the current accordingly. In the aspect depicted in  FIG. 16 , the second relay  2014 , the current sensor  2018 , the position sensor  2020 , and the current detection module  2030  collectively form the motor control circuit  2028 . In the aspect depicted in  FIG. 17 , the second relay  2014 , the current sensor  2018 , the position sensor  2020 , and the controller  2034  collectively form the motor control circuit  2028 . As described below, the motor control circuit  2028  controls the current to the motor  2010  by interrupting the current based upon the sensed current, thus deactivating the motor  2010  when certain conditions occur. 
     The switch  2002  is activated when an operator of the surgical instrument  100  initiates the firing of the clamping member  550  to clamp the end effector  500  and cut and/or staple tissue. The first limit switch  2004  is configured to remain open when the cutting/stapling operation of the end effector  500  is not yet complete. When the first limit switch  2004  is open, the coil  2022  of first relay  2012  is de-energized, thus forming a conductive path between the power source  2008  and second relay  2014  via a normally-closed contact of relay  2012 . The coil  2026  of the second relay  2014  is controlled by the current detection module  2030  and the position sensor  2020  as described below. When the coil  2026  of the second relay  2014  and the coil  2022  of the first relay  2022  are de-energized, a conductive path between the power source  2008  and a normally-closed contact of the third relay  2016  is formed. The third relay  2016  controls the rotational direction of the motor  2010  based on the states of switches  2004 ,  2006 . When first limit switch  2004  is open and the second limit switch  2006  is closed (indicating that the clamping member  550  has not yet fully deployed distally), the coil  2024  of the third relay  2016  is de-energized. Accordingly, when coils  2022 ,  2024 ,  2026  are collectively de-energized, current from the power source  2008  flows through the motor  2010  via the normally-closed contacts of the third relay  2016  and causes the forward rotation of the motor  2010 , which in turn causes the clamping member  550  to be driven distally by the motor  2010  to clamp the end effector  500  and cut and/or staple tissue. 
     When the clamping member  550  has been fully advanced distally, the first limit switch  2004  is configured to close. When the first limit switch  2004  is closed, the coil  2022  of the first relay  2012  is energized and the coil  2024  of third relay  2016  is energized via a normally open contact of relay  2012 . Accordingly, current now flows to the motor  2010  via normally-open contacts of relays  2012 ,  2016 , thus causing reverse rotation of the motor  2010  which in turn causes the clamping member  550  to retract from its distal position and the first limit switch  2004  to open. The second limit switch  2004  is configured to open when the clamping member  550  is fully retracted. Coil  2022  of relay  2012  remains energized until the second limit switch  2006  is opened, indicating the complete retraction of the clamping member  550 . 
     The magnitude of current through the motor  2010  during its forward rotation is indicative of forces exerted upon the clamping member  550  as it is driven distally by the motor  2010 . If a staple cartridge  702  is not loaded into the end effector  500 , an incorrect staple cartridge  702  is loaded into the end effector  500 , or if the clamping member  550  experiences unexpectedly high resistance from the tissue as it cuts and/or staples the tissue, the resistive force exerted against the clamping member  550  causes an increase in motor torque, which thereby causes the motor current to increase. If the motor current exceeds a threshold, the motor control circuit  2028  can cut off the electrical current to the motor  2010 , deactivating the motor and thus pausing the advancement of the clamping member  550 . Accordingly, by sensing the current through the motor  2010 , the motor control circuit  2028  can differentiate between normal operational thresholds of the deployment of the clamping member  550  and potential error conditions. 
     The current sensor  2018  may be coupled to a path of the circuit  2000  that conducts current to the motor  2010  during its forward rotation. The current sensor  2018  may be any current sensing device (e.g., a shunt resistor, a Hall effect current transducer, etc.) suitable for generating a signal (e.g., a voltage signal) representative of sensed motor current. The generated signal may be input to the current detection module  2030  for processing therein. According to the aspect depicted in  FIG. 16 , the current detection module  2030  may be configured for comparing the signal generated by the current sensor  2018  to a threshold signal (e.g., a threshold voltage signal) via a comparator circuit  2032  for receiving the threshold and current sensor  2018  signals and generating a discrete output based on a comparison of the received signals. In some aspects, a value of the threshold signal may be empirically determined a priori by measuring the peak signal generated by the current sensor  2018  when the clamping member  550  is initially deployed (e.g., over an initial period or length of its distal movement) during a cutting and stapling operation. In other aspects, the value of the threshold signal can be a pre-determined value that can, in one example, be retrieved from a memory. 
     In some aspects, it may be desirable to limit the comparison of the sensed motor current to the threshold value to a particular position or range(s) of positions along the firing stroke of the clamping member  550 . In these aspects, the motor control circuit  2028  further includes a position sensor  2020  that is configured to generate a signal indicative of the position of the clamping member  550  (or alternatively, a component of the second or third force/rotation transmitting/converting assemblies  250 ,  260  for aspects wherein the motor  2010  represented in  FIGS. 16 and 17  drives the second or third force/rotation transmitting/converting assemblies  250 ,  260 ). The position sensor  2020  can include, for example, the position sensing assembly depicted in  FIG. 18  and described in fuller detail below. The position sensor  2020  is connected in series with the comparator circuit  2032  (or the microcontroller  2034  of the aspect depicted in  FIG. 17 ) to limit the comparison based on the position of the clamping member  550 . Accordingly, if the signal generated by the current sensor  2018  exceeds the threshold signal (indicating that unexpectedly high resistance is being encountered by the clamping member  550 ) and the clamping member  550  is within a particular zone as determined by the position sensor  2020 , the coil  2026  of the second relay  2014  will be energized. This causes normally-closed switch of the second relay  2014  to open, thereby interrupting current flow to the motor  2010  and pausing the advancement of the clamping member  550 . In this way, if the threshold signal is exceeded when the position of the clamping member  550  is not at a position that activates the position sensor  2020 , then the motor control circuit  2038  will not deactivate the motor  2010 , regardless of the result of the comparison. In other aspects, the motor control circuit  2038  is configured to monitor the motor current along the entirety of the firing stroke of the clamping member  550 . In these aspects, the motor control circuit  2038  lacks the position sensor  2020  (or the position sensor  2020  is deactivated) and the output of the comparator circuit  2032  (or the microcontroller  2034 ) is fed directly to the second relay  2014 . Accordingly, if the signal generated by the current sensor  2018  exceeds the threshold signal at any point along the firing stroke of the clamping member  550 , then current flow to the motor  2010  is interrupted, in the manner described above. 
     According to the aspect depicted in  FIG. 17 , the motor control circuit  2028  can include a processor-based microcontroller  2034  in lieu of the current detection module  2030  described above. Although not shown for purposes of clarity, the microcontroller  2034  may include components well known in the microcontroller art such as, for example, a processor, a random access memory (RAM) unit, an erasable programmable read-only memory (EPROM) unit, an interrupt controller unit, timer units, analog-to-digital conversion (ADC) and digital-to-analog conversion (DAC) units, and a number of general input/output (I/O) ports for receiving and transmitting digital and analog signals. In on example, the microcontroller  2034  includes motor controllers comprising A3930/31K motor drivers from Allegro Microsystems, Inc. The A3930/31K motor drivers are designed to control a 3-phase brushless DC (BLDC) motor with N-channel external power MOSFETs, such as the motors  152 ,  154 ,  156  ( FIG. 4 ). Each of the motor controllers is coupled to a main controller disposed on the main controller circuit board  142   b  ( FIG. 4 ). The main controller is also coupled to memory, which is also disposed on the main controller circuit board  142   b  ( FIG. 4 ). In one example, the main controller comprises an ARM Cortex M4 processor from Freescale Semiconductor, Inc. which includes 1024 kilobytes of internal flash memory. The main controller communicates with the motor controllers through an FPGA, which provides control logic signals. The control logic of the motor controllers then outputs corresponding energization signals to their respective motors  152 ,  154 ,  156  using fixed frequency pulse width modulation (PWM). 
     The current sensor  2018  and the position sensor  2020  may be connected to analog and digital inputs, respectively, of the microcontroller  2034 , and the coil  2026  of the second relay  2014  may be connected to a digital output of the microcontroller  2034 . It will be appreciated that in aspects in which the output of the position sensor  2020  is an analog signal, the position sensor  2020  may be connected to an analog input instead. Additionally, although the circuit  2000  includes relays  2012 ,  2014 ,  2016 , it will be appreciated that in other aspects the relay switching functionality may be replicated using solid state switching devices, software, and combinations thereof. In certain aspects, for example, instructions stored and executed in the microcontroller  2034  may be used to control solid state switched outputs of the microcontroller  2034 . In such aspects, switches  2004 ,  2006  may be connected to digital inputs of the microcontroller  2034 . 
       FIG. 18  illustrates a schematic diagram of a position sensor  2102  of a surgical instrument  100 , according to one aspect of the present disclosure. The position sensor  2102  may be implemented as an AS5055EQFT single-chip magnetic rotary position sensor available from Austria Microsystems, AG. The position sensor  2102  is interfaced with the controller  2104  to provide an absolute positioning system  2100 . The position sensor  2102  is a low-voltage and low-power component and includes four Hall effect elements  2106 A,  2106 B,  2106 C,  2106 D in an area  2120  of the position sensor  2102  that is located above a magnet that is coupled to a component of the surgical instrument  100 . The magnet can be coupled to, for example, a drive shaft of the motor driving the first force/rotation transmitting/converting assembly  240 , the proximal drive shaft  212  of the first force/rotation transmitting/converting assembly  240 , or a gear assembly that is rotatably driven by the clamping member  550  as the clamping member  550  is translated. In other words, the magnet can be coupled to a component of the surgical instrument  100  such that the angular position of the magnet with respect to the Hall effect elements  2106 A,  2106 B,  2106 C,  2106 D corresponds to a longitudinal position of, for example, the clamping member  550 . A high-resolution ADC  2108  and a smart power management controller  2112  are also provided on the chip. A CORDIC processor  2110  (for Coordinate Rotation Digital Computer), also known as the digit-by-digit method and Volder&#39;s algorithm, is provided to implement a simple and efficient algorithm to calculate hyperbolic and trigonometric functions that require only addition, subtraction, bitshift, and table lookup operations. The angle position, alarm bits, and magnetic field information are transmitted over a standard serial communication interface such as an SPI interface  2114  to the controller  2104 . The position sensor  2102  provides 12 or 14 bits of resolution. The position sensor  2102  may be an AS5055 chip provided in a small QFN 16-pin 4×4×0.85 mm package. 
     The Hall effect elements  2106 A,  2106 B,  2106 C,  2106 D are located directly above the rotating magnet (not shown). The Hall effect is a well-known effect and for expediency will not be described in detail herein; however, generally, the Hall effect produces a voltage difference (the Hall voltage) across an electrical conductor transverse to an electric current in the conductor and a magnetic field perpendicular to the current. A Hall coefficient is defined as the ratio of the induced electric field to the product of the current density and the applied magnetic field. It is a characteristic of the material from which the conductor is made, since its value depends on the type, number, and properties of the charge carriers that constitute the current. In the AS5055 position sensor  2102 , the Hall effect elements  2106 A,  2106 B,  2106 C,  2106 D are capable producing a voltage signal that is indicative of the absolute position of the magnet  1202  in terms of the angle over a single revolution of the magnet  1202 . This value of the angle, which is unique position signal, is calculated by the CORDIC processor  2110  is stored onboard the AS5055 position sensor  2102  in a register or memory. The value of the angle that is indicative of the position of the magnet  1202  over one revolution is provided to the controller  2104  in a variety of techniques, for example, upon power up or upon request by the controller  2104 . 
     The AS5055 position sensor  2102  requires only a few external components to operate when connected to the controller  2104 . Six wires are needed for a simple application using a single power supply: two wires for power and four wires  2116  for the SPI interface  2114  with the controller  2104 . A seventh connection can be added in order to send an interrupt to the controller  2104  to inform that a new valid angle can be read. Upon power-up, the AS5055 position sensor  2102  performs a full power-up sequence including one angle measurement. The completion of this cycle is indicated as an INT output  2118 , and the angle value is stored in an internal register. Once this output is set, the AS5055 position sensor  2102  suspends to sleep mode. The controller  2104  can respond to the INT request at the INT output  2118  by reading the angle value from the AS5055 position sensor  2102  over the SPI interface  2114 . Once the angle value is read by the controller  2104 , the INT output  2118  is cleared again. Sending a “read angle” command by the SPI interface  2114  by the controller  2104  to the position sensor  2102  also automatically powers up the chip and starts another angle measurement. As soon as the controller  2104  has completed reading of the angle value, the INT output  2118  is cleared and a new result is stored in the angle register. The completion of the angle measurement is again indicated by setting the INT output  2118  and a corresponding flag in the status register. 
     Due to the measurement principle of the AS5055 position sensor  2102 , only a single angle measurement is performed in very short time (˜600 μs) after each power-up sequence. As soon as the measurement of one angle is completed, the AS5055 position sensor  2102  suspends to power-down state. An on-chip filtering of the angle value by digital averaging is not implemented, as this would require more than one angle measurement and, consequently, a longer power-up time that is not desired in low-power applications. The angle jitter can be reduced by averaging of several angle samples in the controller  2104 . For example, an averaging of four samples reduces the jitter by 6 dB (50%). 
       FIG. 19  illustrates a logic flow diagram of a process  15000  for controlling a speed of a clamping member  550  during a firing stroke, according to one aspect of the present disclosure. In the following description of the process  15000 , reference should also be made to  FIGS. 102-104 , which depict various sensor assemblies utilized by the process  15000 , and  FIG. 21 , which depicts various firing strokes of the clamping member  550  executed according to the process  15000 . The presently described process  15000  can be executed by a controller, which includes the control circuit depicted in  FIGS. 102-103 , the microcontroller  2104  of  FIG. 104 , or another control circuit and/or processor that is executing logic and/or instructions stored in a memory of the surgical instrument  100 . The process  15000  begins to be executed when the clamping and cutting/stapling operations of the end effector  500  are initiated  15002 . 
     Accordingly, the process  15000  executed by the controller advances  15004  the clamping member  550  from a first or proximal position by energizing the motor  2010  to which the clamping member  550  is operably connected. The advancement of the clamping member  550  between a first or proximal position and a second or distal position can be referred to as a stroke or a firing stroke. During the course of a full stroke of the clamping member  550 , the clamping member  550  will clamp the end effector  500  and then cut and/or staple tissue held thereby. The stroke of the clamping member  550  can be represented, for example, as a graph where the x-axis corresponds to the distance or time over which the clamping member  550  has advanced, as depicted in  FIG. 21 . The actions effectuated by the clamping member  550  can correspond to positions or zones defined within the stroke of the clamping member  550 . For example, there can be a position in the stroke where the clamping member  550  has closed the end effector  500  and is thereafter cutting and/or stapling tissue. As another example, there can be a position in the stroke of the clamping member  550  where the clamping member  550  is no longer ejecting staples or cutting tissue. The controller can also take various actions according to the position of the clamping member  550 . For example, there can be a position where the speed at which the clamping member  550  is driven is controlled or changed by a controller. These positions or zones can refer to actual physical positions at which the clamping member is located or relative positions within the stroke of the clamping member. The positions or zones can alternatively be represented as times in the stroke of the clamping member  550 . 
     As the clamping member  550  is advanced  15004 , the controller determines  15006  whether the clamping member  550  is at or near (i.e., within a tolerance of) a defined position in the firing stroke of the clamping member  550 . A defined position is a pre-defined location in the firing stroke of the clamping member  550  where the controller is configured to increase the clamping member speed (i.e., step up the motor  2010 ) or decrease the clamping member speed (i.e., step down the motor  2010 ). There can be zero, one, or multiple defined positions in the process  15000  executed by the controller. The defined positions can be located at or near the proximal or distal ends of the firing stroke or can be located at any intermediate position therebetween. In some aspects, the closure end position and the firing end position are defined positions wherein the controller can be configured, for example, to slow the speed at which the clamping member  550  is being driven by the motor  2010 . The closure end position corresponds to the location in the firing stroke of the clamping member  550  after the clamping member  550  has closed the end effector  500  and is thereafter cutting tissue and/or firing staples. In one example, slowing the clamping member  550  as it approaches the closure end position can be useful in order to prevent the clamping member  550  from inadvertently colliding with a lockout stop when there is no staple cartridge present in the end effector  500 . The firing end position corresponds to the distal point reached by the clamping member  550  in its firing stroke to cut tissue and/or fire staples from the end effector  500 . In one example, slowing the clamping member  550  as it approaches the firing end position can be useful in order to prevent the clamping member  550  from inadvertently colliding with the distal end of the anvil elongated slot  622 . In yet another aspect, the firing stroke of the clamping member  550  includes an intermediate defined position positioned between the closure end position and the firing end position where the controller is configured to drive the clamping member  550  at a faster speed. 
     In some aspects, the controller determines  15006  whether the clamping member  550  is approaching or located at a defined position by detecting the present position of the clamping member  550  (e.g., via the position sensor  2102 ), retrieving one or more stored positions from a memory, and then comparing the detected position to the one or more stored positions to determine if the detected position matches or is within a tolerance distance from at least one of the stored positions. In other aspects, the controller determines  15006  whether the clamping member  550  is approaching or located at a defined position by sensing the motor current and determining whether the sensed motor current or the rate of change of the sensed motor current has exceeded a particular threshold (as described below in  FIG. 20 ). If the controller determines  15006  that the clamping member  550  is not located at a defined position, the process  15000  proceeds along the NO branch and loops back to continue advancing  15004  the clamping member  550 . 
     If the controller determines  15006  that the clamping member  550  is located at (or within a tolerance of) a defined position, the process  15000  proceeds along the YES branch and then changes  15008  the clamping member speed in the manner dictated by the particular defined position. When the controller determines  15006  that the clamping member  550  is located at or near a defined position, the controller can retrieve the manner in which the clamping member speed is to be changed (e.g., whether the speed is to be increased or decreased, a particular value or speed range to which the speed is to be set, or a function for calculating a value or speed range to which the speed is to be set) from a memory that stores each how the clamping member speed is to be changed in association with each of the stored positions. The controller then controls the motor  2010  to increase or decrease the speed at which the clamping member  550  is driven accordingly. 
     The controller then determines  15010  whether the clamping member  550  is located at a stop position. The controller can determine  15010  the location of the clamping member  550  in the same manner described above, namely via a position sensor  2102  or sensing the motor current relative to one or more thresholds. If the clamping member  550  is located at the stop position, then the process  15000  proceeds along the YES branch and stops  15012 . When the process  15000  executed by the controller stops  15012 , the controller can take various actions, such as cutting the current to the motor  2010  or displaying a notification to the user that the clamping member  550  has stopped. If the clamping member  550  is not located at the stop position, then the process  15000  proceeds along the NO branch and continues to advance  15004  the clamping member  552 . This loop continues until the clamping member  550  reaches the stop position and the process  15000  stops  15012 . 
       FIG. 20  illustrates a logic flow diagram of a process  15100  for detecting a defined position according to motor current, according to one aspect of the present disclosure. In the following description of the process  15100 , reference should also be made to  FIGS. 102-104 , which depict various sensor assemblies utilized by the process  15100 , and  FIG. 21 , which depicts various firing strokes of the clamping member  550  executed according to the process  15100 . The presently described process  15100  can be executed by a controller, which includes the control circuit depicted in  FIGS. 102-103 , the microcontroller  2104  of  FIG. 104 , or another control circuit and/or processor that is executing logic and/or instructions stored in a memory of the surgical instrument  100 . The process  15100  begins to be executed when the cutting/stapling operation of the end effector  500  is initiated  15102 . 
     As the controller controls the motor  2010  to advance  15104  the clamping member  550 , the controller monitors or detects  15106  the motor current (e.g., via the current sensor  2018 ). Further, the controller determines  15108  whether the detected motor current or the rate of change of the detected motor current is greater than or equal to a particular threshold value that is indicative of the firing end position in the stroke of the clamping member  550 . In other words, the controller determines  15108  whether the motor current spikes or peaks above a certain level, either by comparing the value of the motor current or the rate of change of the motor current to a particular threshold. Because the motor current tends to sharply increase above a particular threshold as the clamping member  550  approaches certain positions, such as the closure end position and the firing end position, the controller can be configured to monitor the motor current for an indicative increase in the motor current and then take action to slow the clamping member  550  or otherwise prevent the clamping member  550  as it approaches these positions. Slowing the clamping member  550  in this manner can prevent the clamping member  550  from sharply contacting the distal ends of the anvil assembly  610  and/or cartridge assembly  700 . In some aspects, the controller can be configured to cross-reference the detected motor current with a position detected from a position sensor  2102  to confirm that the clamping member  550  is located at or near a position where it would be expected for the motor current to increase or decrease in the manner that is being detected. If the controller determines  15108  that the motor current has not exceeded the threshold, the process  15100  proceeds along the NO branch and continues advancing  15104  the clamping member  550 . If the controller determines  15108  that the motor current has exceed the end of stroke threshold, the process  15100  proceeds along the YES branch and the process  15100  stops  15110 . In some aspects, when the process  15100  stops  15110  the controller de-energizes the motor  2010 . 
     To provide further explanation regarding the function(s) described above that the controller is configured to execute, the processes  15000 ,  15100  will be discussed in terms of several example firing strokes depicted in  FIG. 21 .  FIG. 21  illustrates a first graph  15200  and a second graph  15202 , each of which depict a first firing stroke  15204 , a second firing stroke  15206 , and a third firing stroke  15208  of the clamping member  550  between an initial or proximal position  15216  and an end or distal position  15218 . The first graph  15200  depicts motor current  15203  versus clamping member displacement distance  15201  and the second graph  2302  depicts clamping member speed  15205  versus clamping member displacement distance  15201  for the example firing strokes  15204 ,  15206 ,  15206  of the clamping member  550 . The displacement distance  15201  axis is delineated into a “CLOSURE” zone, a “CUTTING/STAPLING” zone, and a “STOP” zone, which indicates the action(s) that the clamping member  550  is effectuating in each respective portion of its firing stroke. In combination, the first graph  15200  and the second graph  15202  illustrate the relationship between motor current  15203  and clamping member speed  15205  for different firing strokes  15204 ,  15206 ,  15208  and the resulting actions taken by a controller executing the processes  15000 ,  15100  depicted in  FIGS. 19-20 . 
     For each of the firing strokes  15204 ,  15206 ,  15208 , as the displacement member  550  advances from the initial position  15216  to the closure end position  15210  the motor current sharply increases  15220 ,  15222 ,  15224 . In one example, the controller executing the process  15000  depicted in  FIG. 19  can detect this sharp increase  15220 ,  15222 ,  15224  in the motor current by sensing when the rate of change in the motor current for each of the firing strokes  15204 ,  15206 ,  15208  exceeds a threshold, as depicted in  FIG. 21 . The process  15000  then decreases  15226 ,  15228 ,  15230  the speed of the clamping member  550  accordingly as it reaches the closure end position  15210 . As the clamping member  550  advances past the closure end position  15210 , the controller increases  15232 ,  15234 ,  15236  the speed at which the clamping member  550  is driven until the clamping member  550  is driven within a particular speed range S 1 , S 2 , S 3 . In one example, the controller increases  15232 ,  15234 ,  15236  the speed at which the clamping member  550  is driven until the clamping member  550  is driven within a speed range S 1 , S 2 , S 3  corresponding to the thickness of the tissue clamped at the end effector  500 . 
     In some aspects, such with the second and third firing strokes  15206 ,  15208 , the clamping member  550  is thereafter driven at a consistent speed or within a consistent speed range. In other aspects, such as with the first firing stroke  15204 , the controller is configured to control the motor  2010  to drive the clamping member  550  at varying speeds to account for varying tissue properties. For example, in the first firing stroke  15204  the motor current increases  15238  as the clamping member  550  approaches an intermediate position  15214 , potentially due to the cutting surface  554  of the clamping member  550  encountering increasingly thick tissue. In response, the controller can be configured to decrease  15252  the speed at which the clamping member  550  is driven in order to prevent the motor current from continuing to increase. Decreasing  15252  the clamping member speed reduces the current drawn by the motor  2010  because it lowers the torque on the motor  2010 . In some aspects, the controller can be configured to change the maximum acceptable current or torque limits on the motor  2010  in response to detected conditions. For example, in the first firing stroke  15204  the first or initial maximum acceptable current limit of the motor  2010  is delineated by the upper bound of the current range i 2  that was selected by the controller in accordance with the clamped tissue thickness. However, when the motor current  15238  increases as the clamping member  550  approaches the intermediate position  15214 , the controller can be configured to upwardly adjust the maximum motor current to a second maximum acceptable current limit delineated by the upper bound of the current range i 3 . 
     As the clamping member  550  approaches the firing end position  15212  the motor current sharply increases  15240 ,  15242 ,  15244  for each of the firing strokes  15204 ,  15206 ,  15208  until it reaches a threshold  15215 . The controller executing the process  15000  depicted in  FIG. 19  can detect that the motor current has reached or surpassed this threshold  15215 , which is indicative of the clamping member  550  approaching the firing end position  15212 . The process  15000  then decreases  15246 ,  15248 ,  15250  the speed of the clamping member  550  accordingly in each of the firing strokes  15204 ,  15206 ,  15208  and the clamping member  550  slows as it reaches the stop position  15218  (i.e., the distal most position of its firing stroke). When the clamping member  550  reaches the stop position  15218 , the processes  15000 ,  15100  can stop and the controller can take various actions, such as displaying an alert to the operator of the surgical instrument  100  indicating that the clamping, cutting, and/or stapling by the surgical instrument  100  has been completed. 
     In some aspects, the surgical instrument  100  includes stops that are configured to prevent the clamping member  550  (or another component of the firing drive system) from becoming damaged by inadvertently colliding with the anvil assembly  610  and/or the cartridge assembly  700  at the end of its firing stroke. The stops can be constructed from materials that are deformable, bendable, or configured to strain elastically in order to absorb or attenuate the forces from the clamping member  550  as it is advanced to the terminal position of its firing stroke. The stops can be utilized in combination with, or in lieu of, a controller executing a process, such as the process  15100  depicted in  FIG. 20 , to detect the firing stroke end position and then slow and/or stop the clamping member  550  accordingly. 
       FIGS. 22-25  illustrate various views of a stop member  15300  that is engaged with the elongated slot  15352  of the anvil plate  15350 . In the depicted aspect, the stop member  15300  includes a vertical stem or body  15302 , a base  15304  extending orthogonally from the body  15302 , and one or more flanges  15306   a,    15306   b.  The base  15304  extends across the surface  15364  of the anvil plate  15350 . The flanges  15306   a,    15306   b  bear against the interior surface of the shelf  15356  of the elongated slot  15352  and the base  15304  bears against the surface  15364 , which secures the stop member  15300  within the elongated slot  15352  and thus prevents the stop member  15300  from being withdrawn therefrom. The stop member  15300  can be positioned at or adjacently to the distal end  15354  of the elongated slot  15352  and serve as a physical obstruction or barrier preventing the clamping member  15358  from colliding with the distal end  15354  during the stroke of the clamping member  15358  as it translates from a first or proximal position  15360  to a second or distal position  15362 . 
       FIGS. 26-27  illustrate longitudinal sectional views of an end effector  15454  and a drive assembly including a stop member  15400 . In one aspect, the surgical instrument  100  includes one or more projections  15450  extending from the shaft assembly  203  ( FIG. 1 ) or the end effector  15454 . In the depicted aspect, the projections  15450  extend outwardly from the proximal portion of the end effector  15454 , adjacent to the pivot joint  15452 . The drive beam  15402  includes one or more stop members  15400  extending generally orthogonally therefrom that are configured to contact the projections  15450 . The stop members  15400  are rigidly connected to the drive beam  15402  such that the drive beam  15402  is prevented from being advanced further distally when the stop members  15400  contact the projections  15450 . The stop members  15400  are positioned on the drive beam  15402  such that the clamping member  15404  does not contact the distal end  15458  of the elongated slot  15456  when the stop members  15400  contact the projections  15450 . Stated differently, the distance from the distal end  15458  of the elongated slot  15456  to the projections  15450  is larger than the distance between the distal end of the clamping member  15404  and the stop members  15400 . The projections  15450  and/or the stop members  15400  can be constructed from deformable materials or materials that are configured to strain elastically. 
       FIGS. 28-29  illustrate longitudinal sectional views of an end effector  15454  including a stop member  15500  located distally in the elongated slot  15456 . In the depicted aspect, the end effector  15454  includes a stop member  15500  located at the distal end  15458  of the elongated slot. In this aspect, the stop member  15500  is located within or occupies the distal end  15458  or the distal end  15458  terminates at the stop member  15500 . In either case, the stop member  15500  is positioned such that the clamping member  15404  is configured to contact it when the clamping member  15404  has advanced to the most distal position in its firing stroke. The stop member  15500  can be constructed from deformable materials or materials that are configured to strain elastically. 
       FIG. 30  illustrates a cross-sectional view of the adapter  200 . The adapter  200  can include a locking mechanism  280  that is configured to fix the axial or longitudinal position of the distal drive member  248 . In some cases, it may be desirable for the lock mechanism  280  to control a switch or transmit a signal to the controller to indicate that the lock mechanism  280  is engaged and thus that the motor  2010  should not be activated to attempt to drive the distal drive member  248 . In one aspect, the adapter  200  include a switch (not shown) that is tripped when the camming member  288  of the locking mechanism  280  cams into the recess  249  of the distal drive member  248 . The switch is communicably coupled to the controller of the surgical instrument  100 . If the controller determines that the locking mechanism switch has indicated that the locking mechanism  280  is engaged, then the controller can limit or cut current to the motor  2010  in order to prevent the motor  2010  from attempting to drive the locked distal drive member  248 . Likewise, when the camming member  288  is withdrawn from the recess  249  of the distal drive member  248 , then the switch can be un-tripped or re-tripped to indicate to the controller that the locking mechanism  280  has been disengaged and that the motor  2010  can thus be energized to drive the distal drive member  248 . Such an arrangement can be useful in order to, for example, prevent damage to the motor  2010  and/or locking mechanism  280 . 
     Although various aspects have been described herein, many modifications and variations to those aspects may be implemented. For example, different types of end effectors may be employed. Also, where materials are disclosed for certain components, other materials may be used. The foregoing description and following claims are intended to cover all such modification and variations. 
     Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. 
     Various aspects of the subject matter described herein are set out in the following numbered examples: 
     EXAMPLE 1 
     A surgical instrument comprising motor and a current sensor that is configured to sense a current drawn by the motor. The surgical instrument further comprises a control circuit that is coupled to the motor and the current sensor. The control circuit is configured to detect a position of a clamping member that is drivable by the motor between a first position and a second position. In at least one example, the clamping member is configured to transition an end effector to a closed position as the clamping member moves from the first position to the second position and deploy a plurality of staples from a cartridge that is positioned in the end effector after the end effector is in the closed position as the clamping member moves to the second position. The control circuit is further configured to detect whether the current drawn by the motor exceeds a threshold via the current sensor and, upon detecting that the current drawn by the motor exceeds the threshold, control the motor to change a speed at which the clamping member is driven. 
     EXAMPLE 2 
     The surgical instrument of Example 1, wherein the clamping member is configured to deploy staples from a staple cartridge positioned within the end effector and the current drawn by the motor that exceeds the threshold corresponds to a position of the clamping member wherein the staples have been fully deployed from the staple cartridge. 
     EXAMPLE 3 
     The bsurgical instrument of Examples 1 or 2, wherein a knife is coupled to the clamping member and is driven through the end effector as the clamping member moves from the first position to the second position. The current that is drawn by the motor exceeds the threshold that corresponds to a distal position of the knife. 
     EXAMPLE 4 
     The surgical instrument of Examples 1, 2 or 3, wherein the current drawn by the motor exceeding the threshold corresponds to a position of the clamping member wherein the end effector is in the closed position. 
     EXAMPLE 5 
     The surgical instrument of Examples 1, 2, 3 or 4, wherein the control circuit is configured to control the motor to decrease the speed at which the clamping member is driven. 
     EXAMPLE 6 
     The surgical instrument of Examples 1, 2, 3, 4 or 5, wherein the control circuit is configured to detect whether a value of the current drawn by the motor exceeds the threshold. 
     EXAMPLE 7 
     The surgical instrument of Examples 1, 2, 3, 4, 5 or 6, wherein the control circuit is configured to detect whether a rate of change of the current drawn by the motor exceeds the threshold. 
     EXAMPLE 8 
     A surgical instrument comprising a motor and a current sensor that is configured to sense a current that is drawn by the motor. A control circuit is coupled to the motor and the current sensor. In at least one example, the control circuit is configured to detect a position of a clamping member that is drivable by the motor between a first position and a second position. In at least one example, the clamping member is configured to transition an end effector to a closed position as the clamping member moves from the first position to the second position and deploy a plurality of staples from a cartridge positioned in the end effector after the end effector is in the closed position as the clamping member moves to the second position. The control circuit is further configured to control the motor to change a speed at which the clamping member is driven at a defined position between the first position and the second position and detect the defined position according to the current drawn by the motor via the current sensor. 
     EXAMPLE 9 
     The surgical instrument of Example 8, wherein the clamping member is configured to deploy staples from a staple cartridge that is positioned within the end effector and the defined position corresponds to a position of the clamping member wherein the staples have been fully deployed from the staple cartridge. 
     EXAMPLE 10 
     The surgical instrument of Example 8, wherein the defined position corresponds to a position of the clamping member wherein the end effector is in the closed position. 
     EXAMPLE 11 
     The surgical instrument of Example 8, wherein the defined position corresponds to an increase in the current drawn by the motor above a threshold. 
     EXAMPLE 12 
     The surgical instrument of Example 11, wherein the control circuit is configured to detect whether a value of the current drawn by the motor exceeds the threshold. 
     EXAMPLE 13 
     The surgical instrument of Examples 11 or 12, wherein the control circuit is configured to detect whether a rate of change of the current drawn by the motor exceeds the threshold. 
     EXAMPLE 14 
     The surgical instrument of Example 8, wherein the control circuit is configured to control the motor to decrease the speed at which the clamping member is driven. 
     Many of 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 various instances, the surgical instrument systems described herein can be motivated by a manually-operated trigger, for example. In certain instances, the motors disclosed herein may comprise a portion or portions of a robotically controlled system. Moreover, any of the end effectors and/or tool assemblies disclosed herein can be utilized with a robotic surgical instrument 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 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. 
     Although various devices have been described herein in connection with certain embodiments, modifications and variations to those embodiments may be implemented. Particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined in whole or in part, with the features, structures or characteristics of one ore more other embodiments without limitation. Also, where materials are disclosed for certain components, other materials may be used. Furthermore, according to various embodiments, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to perform a given function or functions. The foregoing description and following claims are intended to cover all such modification and variations. 
     The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, a device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps including, but not limited to, the disassembly of the device, followed by cleaning or replacement of particular pieces of the device, and subsequent reassembly of the device. In particular, a reconditioning facility and/or surgical team can disassemble a device and, after cleaning and/or replacing particular parts of the device, the device can be reassembled for subsequent use. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. 
     The devices disclosed herein may be processed before surgery. First, a new or used instrument may be obtained and, when necessary, cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, and/or high-energy electrons. The radiation may kill bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a medical facility. A device may also be sterilized using any other technique known in the art, including but not limited to beta radiation, gamma radiation, ethylene oxide, plasma peroxide, and/or steam. 
     While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles.