Patent Publication Number: US-11033267-B2

Title: Systems and methods of controlling a clamping member firing rate of a surgical instrument

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; and a control circuit coupled to the motor, the control circuit configured to: detect whether an end effector connectable to the surgical instrument is in a closed position, the end effector configured to receive a cartridge supporting a plurality of staples; and 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 the end effector to the closed position as the clamping member moves from the first position to the second position; and deploy the plurality of staples from the cartridge 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: cause the motor to drive the clamping member at a first rate in a first zone between the first position and the second position; and cause the motor to drive the clamping member at a second rate in a second zone between the first position and the second position; wherein the first rate is less than the second rate. 
     In another aspect, a surgical instrument comprising: a motor; and a control circuit coupled to the motor, the control circuit configured to: detect whether an end effector connectable to the surgical instrument is in a closed position, the end effector configured to receive a cartridge supporting a plurality of staples; and detect a position of a clamping member drivable by the motor between a first position, a second position, and a third position, wherein the clamping member is configured to: transition the end effector to the closed position as the clamping member moves from the first position to the second position; and deploy the plurality of staples from the cartridge as the clamping member moves from the second position to the third position; wherein the control circuit is further configured to: cause the motor to drive the clamping member at a first rate in a first zone between the first position and the second position; and cause the motor to drive the clamping member at a second rate in a second zone between the second position and the third position; wherein the first rate is less than the second rate. 
     In another aspect, a surgical instrument comprising: a motor; and a control circuit coupled to the motor, the control circuit configured to: detect whether an end effector connectable to the surgical instrument is in a closed position, the end effector configured to receive a cartridge supporting a plurality of staples; and detect a position of a clamping member drivable by the motor between a first position, a second position, and a third position, wherein the clamping member is configured to: transition the end effector to the closed position as the clamping member moves from the first position to the second position; and deploy the plurality of staples from the cartridge as the clamping member moves from the second position to the third position; wherein the control circuit is further configured to cause the motor to drive the clamping member at a variable rate corresponding to a location of the clamping member between the second position and the third position, the variable rate being slower nearer to the second position. 
    
    
     
       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. 11  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 monitoring a motor current of a surgical instrument; 
         FIG. 20  is a pair of graphs of various clamping member strokes executed per the logic depicted in  FIG. 19 ; 
         FIG. 21  is a pair of graphs of various clamping member strokes executed per the logic depicted in  FIG. 19 ; 
         FIG. 22  is a diagram of an end effector including a gap sensor and a cartridge identity sensor; 
         FIG. 23  is a schematic diagram of a Hall effect sensor; 
         FIG. 24  is a cutaway view of the end effector partially joined to the distal end of the adapter; 
         FIG. 25  is a sectional of the end effector joined to the distal end of the adapter along the longitudinal axis thereof; 
         FIG. 26  is a logic flow diagram of a process for selecting an initial speed at which to fire the clamping member; and 
         FIG. 27  is a graph of various clamping member strokes executed per the logic illustrated in  FIG. 26 . 
     
    
    
     DESCRIPTION 
     Applicant of the present application owns the following U.S. Patent Applications that were filed on Dec. 15, 2017 and which are each herein incorporated by reference in their respective entireties: 
     U.S. patent application Ser. No. 15/843,485, entitled SEALED ADAPTERS FOR USE WITH ELECTROMECHANICAL SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,743,874; 
     U.S. patent application Ser. No. 15/843,518, entitled END EFFECTORS WITH POSITIVE JAW OPENING FEATURES FOR USE WITH ADAPTERS FOR ELECTROMECHANICAL SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2019/0183496; 
     U.S. patent application Ser. No. 15/843,535, entitled SURGICAL END EFFECTORS WITH CLAMPING ASSEMBLIES CONFIGURED TO INCREASE JAW APERTURE RANGES, now U.S. Patent Application Publication No. 2019/0183498; 
     U.S. patent application Ser. No. 15/843,558, entitled SURGICAL END EFFECTORS WITH PIVOTAL JAWS CONFIGURED TO TOUCH AT THEIR RESPECTIVE DISTAL ENDS WHEN FULLY CLOSED, now U.S. Patent Application Publication No. 2019/0183499; 
     U.S. patent application Ser. No. 15/843,528, entitled SURGICAL END EFFECTORS WITH JAW STIFFENER ARRANGEMENTS CONFIGURED TO PERMIT MONITORING OF FIRING MEMBER, now U.S. Pat. No. 10,743,875; 
     U.S. patent application Ser. No. 15/843,567, entitled ADAPTERS WITH END EFFECTOR POSITION SENSING AND CONTROL ARRANGEMENTS FOR USE IN CONNECTION WITH ELECTROMECHANICAL SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,779,825; 
     U.S. patent application Ser. No. 15/843,556, entitled DYNAMIC CLAMPING ASSEMBLIES WITH IMPROVED WEAR CHARACTERISTICS FOR USE IN CONNECTION WITH ELECTROMECHANICAL SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2019/0183490; 
     U.S. patent application Ser. No. 15/843,514, entitled ADAPTERS WITH FIRING STROKE SENSING ARRANGEMENTS FOR USE IN CONNECTION WITH ELECTROMECHANICAL SURGICAL INSTRUMENTS, now U.S. Pat. No. 10,687,813; 
     U.S. patent application Ser. No. 15/843,501, entitled ADAPTERS WITH CONTROL SYSTEMS FOR CONTROLLING MULTIPLE MOTORS OF AN ELECTRICAL MECHANICAL SURGICAL INSTRUMENT, now U.S. Pat. No. 10,869,666; 
     U.S. patent application Ser. No. 15/843,508, entitled HANDHELD ELECTROMECHANICAL SURGICAL INSTRUMENTS WITH IMPROVED MOTOR CONTROL ARRANGEMENTS FOR POSITIONING COMPONENTS OF AN ADAPTER COUPLED THERETO, now U.S. Pat. No. 10,828,033; 
     U.S. patent application Ser. No. 15/843,689, entitled SYSTEMS AND METHODS OF CONTROLLING A CLAMPING MEMBER, now U.S. Patent Application Publication No. 2019/0183502; and 
     U.S. patent application Ser. No. 15/843,704, entitled METHODS OF OPERATING SURGICAL END EFFECTORS, now U.S. Pat. No. 10,779,826. 
     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  2200  for monitoring a motor current of a surgical instrument  100 , according to one aspect of the present disclosure. In the following description of the process  2200 , reference should also be made to  FIGS. 16-18 , which depict various sensor assemblies utilized by the process  2200 , and  FIGS. 20-21 , which depict various firing strokes of the clamping member  550  executed according to the process  2200 . The presently described process  2200  can be executed by a controller, which includes the control circuit depicted in  FIGS. 16-17 , the microcontroller  2104  of  FIG. 18 , 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  2200  begins to be executed when the clamping and cutting/stapling operations of the end effector  500  are initiated  2202 . 
     Accordingly, the process  2200  executed by the controller advances  2204  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  FIGS. 20-21 . 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 depicted in  FIG. 20 . 
     As the clamping member  550  is advanced  2204 , the controller detects  2206  the motor current via, for example, the current sensor  2018 . The controller then determines  2208  whether the clamping member  550  is at the closure end position. In one example, the controller can determine  2208  whether the clamping member is at the closure end position via the position sensor  2102 . 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 as the clamping member  550  continues to advance distally. In some aspects, the controller can retrieve the closure end position from a memory and then compare the stored closure end position to the detected position of the clamping member  550  to determine if the detected position matches or exceeds the stored closure end position. In other aspects, the controller can determine the closure end position by, for example, monitoring for a peak in the motor current. If the clamping member  550  is not at the closure end position, the process  2200  proceeds along the NO branch and the controller continues causing the motor  2010  to advance  2204  the clamping member  550 . The process  2200  continues this loop until the clamping member  550  is located at the closure end position. 
     If the controller determines  2208  that the clamping member  550  is located at or beyond the closure end position, the process  2200  proceeds along the YES branch and the controller selects  2210  the target firing speed at which the clamping member  550  is to be driven by the motor  2010  according to the value of the motor current at the closure end position. The level of motor current required to close the end effector  500  can be indicative of various properties of the clamped tissue. For example, the value of the motor current at the closure end position can correspond to the thickness of the clamped tissue because the force exerted by the clamping member  550  to clamp tissue is proportional to the thickness of the tissue. As the force exerted by the clamping member  550  or the torque exerted by the motor  2010  is proportional to the current drawn by the motor  2010 , the level of the motor current at the closure end position thus corresponds to the thickness of the clamped tissue. It can be desirable to set the target firing speed at which the clamping member  550  is driven according to the thickness of the clamped tissue because advancing the clamping member  550  too quickly through thick tissue can cause improper staple formation and increase the strain on the motor  2010 . As another example, the level of motor current can also correspond to the anatomical type of the clamped tissue (e.g., lung tissue, gastrointestinal tissue, or cardiac tissue) because the physical resistance exerted on the cutting surface  554  driven by the clamping member  550  can vary for different tissue types. In some aspects, the controller can compare the sensed value of the motor current at the closure end position to a range of motor current values and then determine whether the sensed motor current has exceeded one or more thresholds or falls within one or more zones of the range. The controller can then select  2210  the target firing speed for the clamping member  550  as a particular value or set a tolerance threshold for the target firing speed including a range of values, which correspond to where the sensed motor current lies within the range. 
     After selecting  2210  the target firing speed, the controller then causes the clamping member  550  to advance  2212  at an initial speed. The initial speed and the length of time or distance over which the clamping member  550  is advanced at the initial speed can be set values that are retrieved by the controller from a memory or calculated values that are determined by the controller as a function of the tissue thickness. In some aspects, the controller lacks this step of the process  2200  and instead simply proceeds to advance the clamping member  550  at the determined target speed. The initial speed can be a value that is less than the target firing speed. In other words, the controller can cause the motor  2010  to initially advance the clamping member  550  at a lower speed in a first zone or portion of the firing strike relative to a subsequent portion or zone of the firing stroke. In some aspects, the value of the initial speed can be zero or nearly zero. It can be desirable to advance  2212  the clamping member  550  at a lower speed initially in order to allow the fluid to drain from the tissue clamped at the end effector  500 . Fluid drains from clamped tissue due to the mechanical forces exerted on the tissue by the end effector  500 . In one aspect, the length of time or distance that the clamping member  550  is advanced at the initial speed can vary according to the thickness of the clamped tissue. 
     During the portion of the firing stroke of the clamping member  550  directly following the closure end position, the controller further determines  2214  whether the motor current exceeds a maximum or lockout threshold. The controller can retrieve the lockout threshold from a memory. The sensed motor current exceeding the lockout threshold indicates that the clamping member  550  is not being advanced distally from the closure end position. The clamping member  550  can be prevented from advancing distally in the portion of its firing stroke immediately following the closure end position for a variety of reasons, such as if the end effector  500  lacks a staple cartridge assembly  700 . If the motor current exceeds the lockout threshold, the process  2200  proceeds along the YES branch and stops  2216  in order to reduce strain on the motor  2010 . The controller can thereafter cause the surgical instrument  100  to display an alert to the operator or take other such actions. 
     If the motor current does not exceed the lockout threshold, the process  2200  proceeds along the NO branch the controller then causes the clamping member  550  to advance  2218  at an increasing rate of speed until the speed reaches the target speed value or is within the target speed range (which is a function of the tissue thickness). In some aspects, the rate at which the controller causes the motor  2010  to drive the clamping member  550  to increase the speed of the clamping member  550  is a set or predetermined rate. In other aspects, the rate at which the speed of the clamping member  550  is increased is a function of one or more parameters, such as the tissue thickness. In other words, the controller could be configured to cause the speed of the clamping member  550  to increase more slowly for thicker tissue or increase more quickly for thinner tissue. 
     As the clamping member  550  is advanced distally (i.e., fired), the controller detects  2220  the motor current. The controller accordingly determines  2222  whether the sensed motor current exceeds a threshold value. In one example, the threshold value can be retrieved by the controller from a memory for comparison to the detected  2220  motor current. This threshold can be the same or different than the lockout threshold described above. Furthermore, the threshold can correspond to the tissue thickness, for example. In some aspects, if the controller determines  2222  that the motor current has exceeded the determined threshold, then the process  2200  proceeds along the YES branch and the controller decreases  2224  the firing speed of the clamping member  550 . In other aspects, if the controller determines  2222  that the motor current has exceeded the determined threshold, then the process  2200  proceeds along the YES branch and the controller pauses  2224  the clamping member  550  at its current position in its firing stroke. Decreasing the firing speed of or pausing  2224  the clamping member  550  reduces the torque experienced by the motor  2010  (to zero, in the case of pausing the clamping member  550 ). After a particular length of time or after the clamping member  550  had advanced a particular distance (in the case where the clamping member  550  is slowed, not paused), the process  2200  loops back and the controller again causes the clamping member  550  to advance  2218 . The elapsed time or distance before which the controller begins causing the clamping member  550  to increase in speed can be a set value or can be a function of a tissue parameter (e.g., the tissue thickness). 
     If the controller determines  2222  that the clamping member  550  has not exceeded a threshold, the process  2200  proceeds along the NO branch and the controller then determines  2226  whether the clamping member  550  is located at the firing end position. 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 . If the clamping member  550  has not reached the firing end position, the process  2200  proceeds along the NO branch and loops back. The controller then continues to advance  2218  the clamping member  550  (and increase its speed, as appropriate) and detects  2220  the motor current during the course of the firing stroke to determine  2222  whether the motor current exceeds the threshold. The controller continues this loop until it determines  2226  that the clamping member  550  is located at the firing end position. If the controller determines  2226  that the clamping member  550  is located at the firing end position, the process  2200  proceeds along the YES branch and then stops  2228 . 
     To provide further explanation regarding the function(s) described above that the controller is configured to execute, the process  2200  will be discussed in terms of several example firing strokes depicted in  FIGS. 20-21 .  FIG. 20  illustrates a first graph  2300  and a second graph  2302 , each of which depict a first firing stroke  2304  and a second firing stroke  2306  of the clamping member  550 . The first graph  2300  depicts motor current  2303  versus time  2301  and the second graph  2302  depicts clamping member speed  2305  versus time  2301  for the example firing strokes  2304 ,  2306  of the clamping member  550 . The time  2301  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  2300  and the second graph  2302  illustrate the relationship between motor current  2303  and clamping member speed  2305  for different firing strokes  2304 ,  2306  and the resulting actions taken by a controller executing the process  2200  depicted in  FIG. 19 . 
     As discussed above in connection with  FIG. 19 , the controller executing the process  2200  can be configured to select  2210  the firing speed at which the clamping member  550  is to be driven according to the motor current at the closure end position  2308 . In other words, the controller is configured to select  2210  a firing speed of the clamping member  550  that is appropriate for or that otherwise corresponds to the thickness of the clamped tissue, as indicated by the motor current at the closure end position  2308 . In one aspect, the controller selects the firing speed of the clamping member  550  according to where the sensed motor current at the closure end position  2308  falls within a range of values. In some aspects, this can be expressed as whether the motor current at the closure end position  2308  has surpassed one or more thresholds in a range of motor current values. In other aspects, this can be expressed as whether the motor current at the closure end position  2308  falls within a particular zone or zones in a range of motor current values. 
     In the depicted aspect, there are a first threshold T 1 , a second threshold T 2 , and a third threshold T 3 , which can demarcate zones corresponding to thin tissue, medium tissue, and thick tissue, respectively. In other words, if the motor current at the closure end position  2308  is below T 1 , then the tissue can be considered to be thin because relatively little torque was exerted by the motor  2010  to clamp the end effector  500  on the tissue. Accordingly, if the motor current at the closure end position  2308  has exceeded T 1 , but is below T 2 , then the tissue can be considered to be of medium, normal, or expected thickness. Accordingly, if the motor current at the closure end position  2308  has exceeded T 2 , but is below T 3 , then the tissue can be considered to thick because the motor  2010  was required to exert a high degree of torque to clamp the tissue. If the motor current at the closure end position  2308  exceed T 3 , then the tissue can be considered to be too thick to cut and staple or may have been clamped improperly. In that case, the process  2200  can display a warning to the operator and/or lockout the surgical instrument  100  from advancing the clamping member  550  further. The depiction of three thresholds T 1 , T 2 , T 3  is simply illustrative and the process  2200  can incorporate any number of thresholds, however. The speed at which the clamping member  550  is to be driven can be selected by the process  2200  executed by the controller to correspond to the relative tissue thickness, which is indicated by the motor current at the closure end position  2308 . In the depicted aspect, there are a first speed zone S 1  that is selected if the motor current does not exceed T 1 , a second speed zone S 2  that is selected if the motor current falls between T 1  and T 2 , and a third speed zone S 3  that is selected if the motor current falls between T 2  and T 3 . The first speed zone S 1  to the third speed zone S 3  correspond to increasingly slower speeds. It can be desirable to drive the clamping member  550  at a faster rate through thinner tissue because thin tissue provides little resistance to proper staple formation and thus the operation can be completed more quickly without sacrificing staple quality. Conversely, it can be desirable to drive the clamping member  550  at a slower rate through thicker tissue because staples may not be formed properly in thicker tissue if the sled  712  ( FIG. 10 ) is driven too quickly by the clamping member  550 . Driving the sled  712  at a slower rate thus ensures that the staples fully pierce the tissue and are fully formed against the anvil plate  620  ( FIG. 10 ). 
     The first firing stroke  2304  and the second firing stroke  2306  are examples where the controller determines  2222  that the motor current exceeds a threshold during the course of the clamping member firing stroke and then pauses  2224  the clamping member  550 . For example, in the first firing stroke  2304  the closure motor current  2312  at the closure end position  2308  has exceed the second threshold T 2 ; therefore, the controller selects the slowest speed zone S 3  as the target speed at which the clamping member  550  is to be driven during the cutting/stapling phase of the firing stroke. In the second firing stroke  2306  the closure motor current  2319  at the closure end position  2308  has exceed the first threshold T 1 ; therefore, the controller selects the medium speed zone S 2  as the target speed at which the clamping member  550  is to be driven during the cutting/stapling phase of the firing stroke. The speed zones S 1 , S 2 , S 3  set the upper and lower tolerance thresholds for the speed at which the clamping member  550  is driven by the motor  2010 . If the speed of the clamping member  550  exceeds the upper and lower limits of the speed zone S 1 , S 2 , S 3  selected by the controller, then the controller can be configured to take various actions, such as controlling the motor  2010  to increase or decrease the speed at which the clamping member  550  is driven or adjusting the electrical energy supplied to the motor  2010 . In other words, the speed zones S 1 , S 2 , S 3  represent ranges of acceptable speeds in which the speed at which the clamping member  550  is actually translated can vary without causing the controller to take corrective action. It should be appreciated that although the target speed zones S 1 , S 2 , S 3  are depicted as ranges in the second graph  2302 , they could alternatively be discrete values. In general, it can be desirable to set tolerance ranges for the speed at which the clamping member  550  is advancing because the speed will naturally vary during a firing stroke because tissue is not uniform in thickness, the clamping member  550  tends to slow as the sled  712  ejects staples (which are spaced from each other), and the tissue cutting surface  554  ( FIG. 10 ) may be advancing through different types of tissue with different physical properties. 
     Continuing the description of the first firing stroke  2304 , after the closure end position  2308  the controller causes the speed at which the clamping member  550  is advanced to drop from the closure speed  2332  to an initial speed  2333 , which may be lower than the selected target speed (and in some cases is zero). The initial speed  2333  corresponds to a low initial motor current  2313 . The controller then gradually increases the speed at which the clamping member  550  is driven to a target speed  2334  that is within the target speed range S 3  previously selected by the controller. As the clamping member speed increases, the motor current likewise increases  2314 . If the clamping member  550  does not encounter any abnormal resistance from the tissue as the tissue cutting surface  554  is driven therethrough, the clamping member speed will thus be maintained within the target speed range S 3  through the firing stroke until the stop position  2310 . However, in this example, the speed instead begins decreasing thereafter. As the speed decreases, the motor current increases until it peaks  2315  and reaches the maximum threshold T 3 . The clamping member speed dropping while the motor current is simultaneously increasing indicates that the tissue cutting surface  554  driven by the clamping member  550  is encountering thicker than expected tissue or there is otherwise an error that is causing the torque on the motor  2010  to increase unexpectedly. When unexpectedly thick tissue is encountered, the torque on the motor  2010  can increase while the clamping member speed is, at best, maintained or, in this case, falls. When the motor current meets or exceeds the maximum threshold T 3  (at peak  2315 ), the controller reduces or cuts  2316  the current to the motor  2010 , which cause the clamping member speed to drop  2335  to a lower speed or, in some aspects, to zero (i.e., the clamping member  550  is paused). After a period of time, the controller re-energizes the motor  2010  and gradually increases  2317  the motor current in order to cause the speed at which the clamping member  550  is driven to gradually increase to a target speed  2336  within the target speed range S 3 . As long as the motor current does not re-exceed the maximum threshold T 3 , the clamping member  550  continues to advance until it reaches the stop position  2310 . At that point, the controller causes the motor current to drop  2318  to zero and the clamping member speed likewise drops  2337  to zero as the clamping member slows to a stop due to the motor  2010  being de-energized. 
     A similar series of events described above with respect to the first firing stroke  2304  occurs with respect to the second firing stroke  2306 , except that the controller selects the target speed range as S 2  because the closure motor current  2319  only exceeded the first threshold T 1  at the closure end position  2308 . As with the first firing stroke  2304 , after the closure end position  2308  the controller causes the speed at which the clamping member  550  is advanced to drop from the closure speed  2326  to an initial speed  2327 . The controller then gradually increases the speed at which the clamping member  550  is driven to a target speed  2328  that is within the target speed range S 2  previously selected by the controller. As the clamping member speed increases, the motor current likewise increases  2321 . As with the first firing stroke  3406 , the speed begins decreasing and the motor current increases until it peaks  2322  and reaches the maximum threshold T 3 . As the motor current meets or exceeds the maximum threshold T 3  (at peak  2322 ), the controller reduces or cuts  2323  the current to the motor  2010 , which cause the clamping member speed to drop  2329  to a lower speed or, in some aspects, to zero (i.e., the clamping member  550  is paused). After a period of time, the controller re-energizes the motor  2010  and gradually increases  2324  the motor current to increase the clamping member speed a target speed  2330  within the target speed range S 2 . The time delay prior to the controller re-energizing the motor can vary for different conditions encountered during the firing stroke. As can be noted from either the first graph  2300  or the second graph  2302 , the length of time that the current is cut  2316  in the first firing stroke  2304  is greater than the length of time that the current is cut  2323  in the second firing stroke  2306 . In some aspects, the length of the pause (or the length of time at which the clamping member  550  is driven at a lower or initial speed) can be a function of the tissue thickness. For example, the controller can pause the advancement of the clamping member  550  longer for thicker tissue. The controller continues to advance the clamping member  550  until it reaches the stop position  2338 . At that point, the controller causes the motor current to drop  2325  to zero and the clamping member speed likewise drops  2331  to zero as the clamping member slows to a stop due to the motor  2010  being de-energized. As can further be noted, the stop position  2338 ,  2310  can vary. In some aspects, the location of the stop position  2338 ,  2310  can vary according to the length of the cartridge body  702  present into the end effector  500 . In other aspects, the location of the stop position  2338 ,  2310  can be set by the operator of the surgical instrument  100  to a shorter (i.e., more proximal) position than the maximum stop position. 
       FIG. 21  illustrates a third graph  2400  and a fourth graph  2402 , each of which depict a third firing stroke  2404 , a fourth firing stroke  2406 , and a fifth firing stroke  2408  of the clamping member  550 . The third graph  2400  depicts motor current  2403  versus clamping member displacement distance  2401  and the fourth graph  2402  depicts clamping member speed  2405  versus displacement distance  2401  for the example firing strokes  2404 ,  2406 ,  2408  of the clamping member  550 . The displacement distance  2401  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 driving in each respective portion of its firing stroke. In combination, the third graph  2400  and the fourth graph  2402  illustrate the relationship between motor current  2403  and clamping member speed  2405  for different firing strokes  2404 ,  2406 ,  2408  and the resulting actions taken by a controller executing the process  2200  depicted in  FIG. 19 . 
     As discussed above in connection with  FIG. 19 , the controller executing the process  2200  can be configured to select  2210  the firing speed at which the clamping member  550  is to be driven according to the motor current at the closure end position  2410 . In other words, the controller is configured to select  2210  a firing speed for the clamping member  550  that is appropriate for or that otherwise corresponds to the thickness of the clamped tissue, as indicated by the motor current at the closure end position  2410 . In one aspect, the controller selects the firing speed of the clamping member  550  according to where the sensed motor current at the closure end position  2410  falls within a range of values. In some aspects, this can be expressed as whether the motor current at the closure end position  2410  has surpassed one or more thresholds in a range of motor current values. In other aspects, this can be expressed as whether the motor current at the closure end position  2410  falls within a particular zone or zones in a range of motor current values. In the depicted aspect, the motor current  2403  includes a first zone i 1 , a second zone i 2 , and a third zone i 3 . The zones may or may not be contiguous with each other. The depiction of three zones i 1 , i 2 , i 3  along the axis of the motor current  2403  is simply illustrative and the process  2200  can incorporate any number of thresholds, however. 
     As also discussed above in connection with  FIG. 19 , the process  2200  executed by the controller can be configured to determine  2214  whether the motor current exceeds a lockout threshold  2415 . The third firing stroke  2404  represents an example firing stroke wherein the controller determines  2214  that the lockout threshold  2415  is exceeded. In the third firing stroke  2404 , the motor current spikes  2414  in the portion of the firing stroke immediately following the closure end position  2410 , reaching or exceeding the lockout threshold  2415 , as the clamping member speed sharply drops  2416  to zero. In other words, the motor current increases sharply with minimal or no corresponding movement of the clamping member  550 . When the motor current reaches the lockout threshold  2415 , the process  2200  executed by the controller stops  2216  and the controller can display a warning to the operator and/or lockout the surgical instrument  100  from firing the clamping member  550 . In one example, the spike  2414  in the motor current exhibited by the third firing stroke  2404  directly after the closure end position  2410  can be indicative of a cartridge  702  not being present or being improperly loaded in the end effector  500 . 
     The fourth firing stroke  2406  is an example where controller determines  2222  that the motor current exceeds a threshold during the course of the clamping member stroke and then decreases  2224  the speed of the clamping member  550 . In the fourth firing stroke  2406 , the closure motor current  2418  falls within the i 2  zone; therefore, the controller selects S 2  as the target speed range  2436 . After the closure end position  2410 , the controller causes the clamping member speed to decrease from the closure speed  2432  to an initial speed  2434 . The controller then causes the displacement member speed to increase from the initial speed  2434  to a target speed  2436  in the selected speed range S 2 . It should be noted that the initial speed  2434  can be a set value or a range of values. The motor current correspondingly increases  2420  as the displacement member speed increases. As the clamping member  550  continues advancing in the fourth firing stroke  2406 , the clamping member  550  hits a point where the motor current sharply increases  2422  such that it exceeds a threshold demarcated by the upper boundary of the i 2  zone. The sharp increase  2422  in the motor current is indicative of the cutting surface  554  being driven through an unexpectedly thick portion of the clamped tissue. In this example, there are multiple thresholds (demarcated by the boundaries of the current zones i 1 , i 2 , i 3 ) that the controller compares the sensed motor current against to determine  2222  whether to decrease  2224  the displacement member speed or pause the clamping member  550 . This is in contrast to the first firing stroke  2304  and the second firing stroke  2306  where the controller only took action (i.e., paused the clamping member  550  in the particular examples) when the motor current reached or exceeded a singular maximum threshold (T 3 ). When the motor current exceeds the threshold, the controller decreases  2438  the clamping member speed from the original speed range S 2  to the lower speed range S 3 . The controller then causes the motor  2010  to advance the clamping member  550  at the lower speed  2440 . As the clamping member  550  advances at the lower speed range S 3 , the motor current continues  2424  in the higher current range i 3  until it sharply decreases  2426  past the lower boundary of the i 3  current zone. The sharp decrease  2426  in the motor current is indicative of the cutting surface  554  being driven through a thinner portion of the clamped tissue because less current is required to advance the clamping member  550  at the target speed. When the motor current reaches or exceeds the threshold represented by this lower boundary, the controller then causes the motor  2010  to increase  2442  the clamping member speed from the lower speed range S 3  back to the original speed range S 2 . Through the remaining portion of the fourth firing stroke  2406 , the displacement member speed continues  2444  within the target speed range S 2  (with the motor current likewise continuing  2428  with its respective range i 2 ) until the clamping member  550  reaches the firing end position  2412 . When the clamping member  550  reaches the firing end position  2412 , the controller cuts  2430  the motor current and the clamping member speed correspondingly drops  2446  to zero as the motor  2010  is de-energized. 
     The fifth firing stroke  2408  represents a firing stroke wherein the clamping member  550  is driven through clamped tissue lacking any significant variations in thickness. In the fifth firing stroke  2408 , the closure motor current  2448  falls within the i 1  zone; therefore, the controller selects S 1  as the target speed range  2458 . After the closure end position  2410 , the controller causes the clamping member speed to decrease from the closure speed  2454  to an initial speed  2456 . The controller then causes the displacement member speed to increase from the initial speed  2456  to a target speed  2458  in the selected speed range S 3 . In the present example, the clamping member  550  maintains its speed within the target speed  2458  for the entire length of the firing stroke. The motor current is likewise maintained  2450  within the boundaries of the current zone i 1 . In other words, the clamping member  550  does not encounter any portions of tissue that is appreciably thicker or thinner relative to the expected tissue thickness (i.e., the tissue thickness indicated by the closure motor current  2418 ) as the clamping member  550  advances from the closure end position  2410  to the firing end position  2412 . When the clamping member  550  reaches the firing end position  2412 , the controller cuts  2452  the motor current, which causes the clamping member speed to drop  2460  to zero as the motor  2010  is de-energized. 
       FIG. 22  illustrates a diagram of an end effector  10000  including a gap sensor  10006  and a cartridge identity sensor  10010 , according to one aspect of the present disclosure. The gap sensor  10006  is configured to sense the gap or distance between the first jaw member  10004  (i.e., the anvil assembly  610 ) and the second jaw member  10006  (i.e., the cartridge assembly  700 ) by sensing the relative position of a magnet  10008 . The position sensor  10006  can include a Hall effect sensor, among other sensors configured to detect the relative distance between components. In one aspect depicted in  FIG. 23 , the position sensor  10006  comprises a Hall element  10100 , an amplifier  10102 , and a power source  10104 . The Hall element comprises a first input terminal  10108 A and a second input terminal  10108 B. The first and second input terminals  10108 A,  10108 B are configured to receive a constant input current from the power source  10104 . When no magnetic field is present, the input current enters the first input terminal  10108 A and exits the second input terminal  10108 B with no loss of voltage potential to either side of the Hall element  10100 . As a magnetic field is applied to the Hall element  10100 , such as, for example, by magnet  10008 , a voltage potential is formed at the sides of the Hall element  10100  due to the deflection of electrons flowing through the Hall element  10100 . A first output terminal  10108 C and a second output terminal  10108 D are located at opposite sides of the Hall element  10100 . The first and second output terminals  10108 C,  10108 D provide the voltage potential caused by the magnetic field to the amplifier  10102 . The amplifier  10102  amplifies the voltage potential experienced by the Hall element  10100  and outputs the amplified voltage to an output terminal  10106 . Therefore, the output of the position sensor  10006  corresponds to the relative distance of the magnet  10008  to the Hall element  10100 . Detecting the distance between the jaw members  10006 ,  10008  can be beneficial because this distance corresponds to the thickness of the grasped tissue when the end effector  10000  is clamped. Therefore, sensing the distance between the jaw member  10006 ,  10008  can be used in lieu of, or in addition to, determining the tissue thickness from the motor current to clamp the end effector  10000 , as described above. 
     Referring back to  FIG. 22 , the cartridge identity sensor  10010  is configured to sense the type or identity of a cartridge  702  present in the end effector  10000 . In one aspect where the end effector  10000  is a MULU with replaceable cartridges  702 , the cartridge identity sensor  10010  includes a receiver that is configured to receive a signal (e.g., a RF signal) transmitted from the cartridge  702 . In another aspect where the end effector  10000  is a MULU, the cartridge identity sensor  10010  includes an electrical contact that is configured to contact a corresponding electrical contact of the cartridge  702  when the cartridge  702  is inserted into the end effector  10000 . Upon the cartridge  702  being inserted, the cartridge  702  transmits a signal through the electrically connected electrical contacts, which is received by a controller of the surgical instrument  100  to identity the cartridge  702 . 
     In another aspect where the end effector  10000  is a SULU, the cartridge identity sensor  10010  is configured to detect when the end effector  10000  is mated to the adapter  200 . In this aspect depicted in  FIGS. 24-25 , the terminal end  10206  of the adapter  200  includes one or more electrical contacts  10200 , which each include a bent portion  10202 . The end effector  500  further includes a memory disposed within or on the end effector housing  10201 . The memory includes a memory chip and one or more electrical contacts  10204  electrically connected to the memory chip. The memory chip is configured to store one or more parameters relating to the end effector  500 . The parameters can include a serial number of the end effector  500 , a type of the end effector  500  and/or the cartridge  702  therein, a size of end effector  500  and/or the cartridge  702  therein, a staple size, information identifying whether the end effector  500  has been fired, a length of the end effector  500  and/or the cartridge  702  therein, maximum number of uses of the end effector  500 , and combinations thereof. When the end effector  500  is mated to the adapter  200 , the end effector electrical contacts  10204  engaged the adapter electrical contacts  10200 . The memory chip is configured to communicate the presence of the end effector  500  and one or more of the parameters of the end effector  500  described herein, via electrical contacts  10200 ,  100204 , upon engagement of the end effector  500  with the adapter  200 . 
       FIG. 26  illustrates a logic flow diagram of a process  10300  for selecting an initial speed at which to fire the clamping member  550 , according to one aspect of the present disclosure. In the following description of the process  10300 , reference should also be made to  FIGS. 22-25 , which depict various sensor assemblies utilized by the process  10300 , and  FIG. 27 , which depicts various firing strokes of the clamping member  550  executed according to the process  10300 . The presently described process  10300  can be executed by a controller, which includes the control circuit depicted in  FIGS. 16-17 , the microcontroller  2104  of  FIG. 18 , 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  10300  begins to be executed when the clamping and cutting/stapling operations of the end effector  500  are initiated  10302 . 
     Accordingly, the process  10300  executed by the controller first advances  10304  the clamping member  550  by energizing the motor  2010  to which the clamping member  550  is operably connected. The controller then determines  10306  whether the clamping member  550  is at the closure end position. In one example, the controller can determine  10306  whether the clamping member  550  is at the closure end position via the position sensor  2102  ( FIG. 18 ). 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 some aspects, the controller can retrieve the closure end position from a memory and then compare the known closure end position to the sensed position of the clamping member  550 . In other aspects, the controller can determine the closure end position by monitoring for a peak in the motor current. If the clamping member  550  is not at the closure end position, the process  10300  proceeds along the NO branch and the controller continues causing the motor  2010  to advance  10304  the clamping member  550 . The process  2200  continues this loop until the clamping member  550  is located at or beyond the closure end position. 
     If the controller determines  10306  that the clamping member  550  is located at or beyond the closure end position in its firing stroke, the process  10300  proceeds along the YES branch and then determines  10308  the gap distance between the anvil assembly  610  and the cartridge assembly  700 . In one example, the controller determines  10308  the gap distance via the gap sensor  10006 . The controller then determines  10310  the type or identity of the cartridge  702  and/or the end effector  500 . In one example, the controller determines  10310  the type or identity of the cartridge  702  via the cartridge identity sensor  10100 . The cartridge then determines  10312  whether the gap distance is acceptable for the sensed cartridge type. Different types of cartridges  702  have different acceptable tolerance ranges; therefore, a gap distance between the anvil assembly  610  and the cartridge assembly  700  that is suitable (i.e., within operational tolerances) for one type of cartridge  702  may not be suitable for another type of cartridge  702 . If the controller determines that the gap distance is not suitable for the given cartridge type, the process  10300  proceeds along the NO branch and stops  10314 . In that case, the process  10300  can display a warning to the operator and/or lockout the surgical instrument  100  from firing the clamping member  550 . 
     If the controller determines that the gap distance is suitable for the given cartridge type, the process  10300  proceeds along the YES branch and next determines  10316  the target firing speed for the clamping member  550  according to the sensed gap distance and the sensed cartridge type. In one aspect, the controller can select a target firing speed according to whether the sensed gap distance exceeds one or more thresholds or falls within one or more zones within a range of gap distances that are particular to a given cartridge type. In other words, different cartridge types may have different tolerance ranges for the speeds at which the clamping member  550  can be advanced for different thicknesses of the clamped tissue. Across cartridge types, the controller can be configured to generally select slower firing speeds for thicker tissue and faster firing speeds for thinner tissue; however, whether a given thickness of tissue is considered to be relatively thick or relatively thin will vary according to the cartridge type. After determining  10316  the appropriate target firing speed, the process  10300  stops  10318 . 
     To provide further explanation regarding the function(s) described above that the controller is configured to execute, the process  10300  will be discussed in terms of several example firing strokes depicted in  FIG. 27 .  FIG. 27  illustrates a graph  10400  that depicts several firing strokes  10406 ,  10408 ,  10410 ,  10412 ,  10414 ,  10416 ,  10418  of the clamping member  550  corresponding to different cartridge types. In the graph  10400 , the first firing stroke  10406 , the second firing stroke  10408 , the fifth firing stroke  10414 , and the seventh firing stroke  10418  correspond to a first cartridge type; the third firing stroke  10410  and the sixth firing stroke  10416  correspond to a second cartridge type; and the fourth firing stroke  10412  corresponds to a third cartridge type. The graph  10400  depicts the gap distance  10404  of the end effector  500  versus the displacement distance  10402  of the clamping member  550 . The resulting actions taken by a controller executing the process  10300  (i.e., determining  10316  the firing speed) depends upon gap distance  10404  at the closure end position  10420  for the cartridge type of each firing stroke. The graph  10400  also depicts a variety of thresholds x 1  . . . x 6  along the gap distance  10404  axis that delineate zones therebetween. The sequentially increasing thresholds x 1  . . . x 6  can correspond to increasingly larger values of the gap distance  10404 . Each cartridge type does not necessarily utilize all of the depicted thresholds x 1  . . . x 6  and different cartridge types can use the same or different thresholds x 1  . . . x 6  and/or zones, as will be discussed below. Furthermore, although six thresholds x 1  . . . x 6  are depicted, the process  10300  executed by the controller can utilize any number of thresholds and/or zones in practice. 
     For the first cartridge type, the thresholds x 6 , x 5 , and x 3  define the zones that determine the firing speed selected by the controller. For example, at the closure end position  10420  the first firing stroke  10406  is located at a position  10407  exceeding x 6 . Exceeding the x 6  threshold corresponds to the clamped tissue being too thick to cut and staple for the given cartridge type or having been clamped improperly. In this case, the controller can display a warning to the operator and/or lockout the surgical instrument  100  from firing the clamping member  550 . The second firing stroke  10408  is located at a position  10409  in a zone between x 6  and x 5  at the closure end position  10420 , which corresponds to a large gap or thick tissue for the given cartridge type. Therefore, the controller can select a slower firing speed for the clamping member  550 . The fifth firing stroke  10414  is located at a position  10415  in a zone between x 5  and x 3  at the closure end position  10420 , which corresponds to a medium gap or medium, normal, or expected tissue thickness for the given cartridge type. Therefore, the controller can select a medium or normal firing speed for the clamping member  550 . The seventh firing stroke  10418  is located at a position  10419  in a zone below x 3  at the closure end position  10420 , which corresponds to a small gap or thin tissue for the given cartridge type. Therefore, the controller can select a fast firing speed for the clamping member  550 . 
     The relevant thresholds can vary for different cartridge types. For the second cartridge type, the x 4  threshold delineates zones defining a fast firing speed and a normal firing speed. For example, the third firing stroke  10410  is located at a position  10411  in a zone above x 4  at the closure end position  10420 , which corresponds to a medium gap or a medium, normal, or expected tissue thickness for the given cartridge type. Therefore, the controller can select a medium or normal firing speed for the clamping member  550 . The sixth firing stroke  10416  is located at a position  10417  in a zone below x 4  at the closure end position  10420 , which corresponds to a small gap or thin tissue for the given cartridge type. Therefore, the controller can select a fast firing speed for the clamping member  550 . 
     The relevant thresholds can also be shared between different cartridge types. For the third cartridge type, the x 4  threshold delineates zones defining a fast firing speed and a normal firing speed (as with the second cartridge type of the third firing stroke  10410  and the sixth firing stroke  10416 ). For example, the fourth firing stroke  10412  is located at a position  10413  in a zone below x 4  at the closure end position  10420 , which corresponds to a small gap or thin tissue for the given cartridge type. Therefore, the controller will select a fast firing speed for the clamping member  550 . 
     In sum, the process  10300  executed by the controller can select the appropriate firing speed for the clamping member  550  during the cutting/stapling portion of its firing stroke according to where the sensed gap distance between the anvil assembly  610  and the cartridge assembly  700  falls relative to various tolerance ranges, which may be unique to each cartridge type. The process  10300  thus allows the controller to customize the speed at which the clamping member  550  is fired to cut and/or staple tissue according to the thickness of the clamped tissue and the cartridge type. 
     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 a motor that includes a control circuit coupled thereto and configured to detect whether an end effector that is connectable to the surgical instrument is in a closed position. In at least one example, the end effector is configured to receive a cartridge that supports a plurality of staples. The control circuit is also configured to detect a position of a clamping member that is drivable by the motor between a first position and a second position. The clamping member is configured to transition the end effector to the closed position as the clamping member moves from the first position to the second position and deploy the plurality of staples from the cartridge 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 cause the motor to drive the clamping member at a first rate in a first zone between the first position and the second position and cause the motor to drive the clamping member at a second rate in a second zone between the first position and the second position. In at least one example, the first rate is less than the second rate. 
     EXAMPLE 2 
     The surgical instrument of Example 1, wherein the first zone is located proximally relative to the second zone. 
     EXAMPLE 3 
     The surgical instrument of Example 1, wherein the first zone is located prior to the second zone. 
     EXAMPLE 4 
     The surgical instrument of Example 1, 2 or 3, wherein a length of the first zone corresponds to a thickness of a tissue grasped at the end effector. 
     EXAMPLE 5 
     The surgical instrument of Example 3, wherein the surgical instrument comprises a sensor that is configured to detect a gap between the jaw members of the end effector. The gap corresponds to the thickness of the tissue. 
     EXAMPLE 6 
     The surgical instrument of Examples 4 or 5, wherein the control circuit is configured to detect a current of the motor as the end effector transitions to the closed position, the current of the motor corresponding to the thickness of the tissue. 
     EXAMPLE 7 
     A surgical instrument comprising a motor that includes a control circuit coupled thereto wherein the control circuit is configured to detect whether an end effector that is connectable to the surgical instrument is in a closed position. In at least one example, the end effector is configured to receive a cartridge that supports a plurality of staples. The control circuit is further configured to detect a position of a clamping member that is drivable by the motor between a first position, a second position, and a third position. The clamping member is configured to transition the end effector to the closed position as the clamping member moves from the first position to the second position. The clamping member is further configured to deploy the plurality of staples from the cartridge as the clamping member moves from the second position to the third position. The control circuit is further configured to cause the motor to drive the clamping member at a first rate in a first zone between the first position and the second position and cause the motor to drive the clamping member at a second rate in a second zone between the second position and the third position. In at least one example, the first rate is less than the second rate. 
     EXAMPLE 8 
     The surgical instrument of Example 7, wherein the first zone is located proximally relative to the second zone. 
     EXAMPLE 9 
     The surgical instrument of Example 7, wherein the first zone is located prior to the second zone. 
     EXAMPLE 10 
     The surgical instrument of Examples 7, 8 or 9, wherein a length of the first zone corresponds to a thickness of a tissue grasped at the end effector. 
     EXAMPLE 11 
     The surgical instrument of Example 10, wherein the surgical instrument comprises a sensor configured to detect a gap between jaw members of the end effector, the gap corresponding to the thickness of the tissue. 
     EXAMPLE 12 
     The surgical instrument of Examples 10 or 11 wherein the control circuit is configured to detect a current of the motor as the end effector transitions to the closed position, the current of the motor corresponding to the thickness of the tissue. 
     EXAMPLE 13 
     A surgical instrument comprising a motor that includes a control circuit coupled thereto that is configured to detect whether an end effector that is connectable to the surgical instrument is in a closed position. In at least one example, the end effector is configured to receive a cartridge that supports a plurality of staples. The control circuit is further configured to detect a position of a clamping member that is drivable by the motor between a first position, a second position, and a third position. The clamping member is configured to transition the end effector to the closed position as the clamping member moves from the first position to the second position and deploy the plurality of staples from the cartridge as the clamping member moves from the second position to the third position. The control circuit is further configured to cause the motor to drive the clamping member at a variable rate corresponding to a location of the clamping member between the second position and the third position. In at least one example, the variable rate is slower nearer to the second position. 
     EXAMPLE 14 
     The surgical instrument of Example 13, wherein the control circuit is configured to cause the motor to drive the clamping member at a slower rate for a period of time corresponding to a thickness of a tissue grasped at the end effector. 
     EXAMPLE 15 
     The surgical instrument of Examples 13 or 14, wherein the surgical instrument comprises a sensor configured to detect a gap between jaw members of the end effector, the gap corresponding to the thickness of the tissue. 
     EXAMPLE 16 
     The surgical instrument of Examples 13, 14 or 15, wherein the control circuit is configured to detect a current of the motor as the end effector transitions to the closed position, the current of the motor corresponding to the thickness of the tissue. 
     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.