Patent Description:
For further background, <CIT> describes a stapling assembly that comprises an anvil configured to deform staples. The anvil comprises a tissue-engaging surface and a pair of forming pockets defined in the tissue-engaging surface and aligned along a longitudinal pocket axis, wherein the pair of forming pockets is configured to deform corresponding legs of a staple. The pair of forming pockets comprises a proximal forming pocket and a distal forming pocket. Each pocket comprises a pair of sidewalls extending between the forming surface and the tissue-engaging surface. Each sidewall comprises discrete sidewall portions oriented at different angles with respect to the tissue-engaging surface.

<CIT> describes an instrument assembly comprising a shaft comprising a first drive portion of a drive system, an end effector comprising a second drive portion of the drive system, and an articulation joint rotatably connecting the end effector to the shaft. The end effector is rotatable between a first position and a second position about the articulation joint, wherein the first drive portion is not operably engaged with the second drive portion when the end effector is in the first position, and operably engaged with the second drive portion when the end effector is in the second position. The end effector comprises a first jaw and a second jaw, wherein the first jaw is movable relative to the second jaw between an open position and a closed position within a closure plane, and wherein the end effector is rotatable within an articulation plane which is coplanar with the closure plane. <CIT> constitutes prior art according to Article <NUM>(<NUM>) EPC and discloses a stapler with means for stopping tissue to extend proximally beyond the proximal-most one of a plurality of staple pockets.

<CIT> discloses a stapler comprising means to minimize pinch points that may otherwise be present between an anvil mounting portion and a distal end of a distal closure member when the anvil is in its fully opened position.

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:.

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

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'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 j oint 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> and <FIG> depict a motor-driven surgical cutting and fastening instrument <NUM> that may or may not be reused. The instrument <NUM> includes a previous housing <NUM> that comprises a handle <NUM> that is configured to be grasped, manipulated and actuated by the clinician. The housing <NUM> is configured for operable attachment to an interchangeable shaft assembly <NUM> that has a surgical end effector <NUM> operably coupled thereto that is configured to perform one or more surgical tasks or procedures. As the present Detailed Description proceeds, it will be understood that the various forms of interchangeable shaft assemblies disclosed herein may also be effectively employed in connection with robotically-controlled surgical systems. Thus, the term "housing" may also encompass a housing or similar portion of a robotic system that houses or otherwise operably supports at least one drive system that is configured to generate and apply at least one control motion which could be used to actuate the interchangeable shaft assemblies disclosed herein and their respective equivalents. In addition, various components may be "housed" or contained in the housing or various components may be "associated with" a housing. In such instances, the components may not be contained with the housing or supported directly by the housing. The term "frame" may refer to a portion of a handheld surgical instrument. The term "frame" may also represent a portion of a robotically controlled surgical instrument and/or a portion of the robotic system that may be used to operably control a surgical instrument. For example, the interchangeable shaft assemblies disclosed herein may be employed with various robotic systems, instruments, components and methods disclosed in <CIT>, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS.

The previous housing <NUM> depicted in <FIG> is shown in connection with an interchangeable shaft assembly <NUM> (<FIG>, <FIG> and <FIG>) that includes an end effector <NUM> that comprises a surgical cutting and fastening device that is configured to operably support a surgical staple cartridge <NUM> therein. The housing <NUM> may be configured for use in connection with interchangeable shaft assemblies that include end effectors that are adapted to support different sizes and types of staple cartridges, have different shaft lengths, sizes, and types, etc. In addition, the housing <NUM> may also be effectively employed with a variety of other interchangeable shaft assemblies including those assemblies that are configured to apply other motions and forms of energy such as, for example, radio frequency (RF) energy, ultrasonic energy and/or motion to end effector arrangements adapted for use in connection with various surgical applications and procedures. Furthermore, the end effectors, shaft assemblies, handles, surgical instruments, and/or surgical instrument systems can utilize any suitable fastener, or fasteners, to fasten tissue. For instance, a fastener cartridge comprising a plurality of fasteners removably stored therein can be removably inserted into and/or attached to the end effector of a shaft assembly.

<FIG> illustrates the surgical instrument <NUM> that includes an interchangeable shaft assembly <NUM> operably coupled to the housing <NUM>. <FIG> illustrates the interchangeable shaft assembly <NUM> detached from the housing <NUM> or handle <NUM>. As can be seen in <FIG>, the handle <NUM> may comprise a pair of interconnectable handle housing segments <NUM> and <NUM> that may be interconnected by screws, snap features, adhesive, etc. In the illustrated arrangement, the handle housing segments <NUM>, <NUM> cooperate to form a pistol grip portion <NUM> that can be gripped and manipulated by the clinician. As will be discussed in further detail below, the handle <NUM> operably supports a plurality of drive systems therein that are configured to generate and apply various control motions to corresponding portions of the interchangeable shaft assembly that is operably attached thereto.

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

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

An arm <NUM> may extend from the closure release button <NUM>. A magnetic element <NUM>, such as a permanent magnet, for example, may be mounted to the arm <NUM>. When the closure release button <NUM> is rotated from its first position to its second position, the magnetic element <NUM> can move toward a circuit board <NUM>. The circuit board <NUM> can include at least one sensor that is configured to detect the movement of the magnetic element <NUM>. A "Hall Effect" sensor (not shown) can be mounted to the bottom surface of the circuit board <NUM>. The Hall Effect sensor can be configured to detect changes in a magnetic field surrounding the Hall Effect sensor caused by the movement of the magnetic element <NUM>. The Hall Effect sensor can be in signal communication with a microcontroller, for example, which can determine whether the closure release button <NUM> is in its first position, which is associated with the unactuated position of the closure trigger <NUM> and the open configuration of the end effector, its second position, which is associated with the actuated position of the closure trigger <NUM> and the closed configuration of the end effector, and/or any position between the first position and the second position.

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

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

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

As indicated above, in at least one form, the longitudinally movable drive member <NUM> has a rack of teeth <NUM> formed thereon for meshing engagement with a corresponding drive gear <NUM> of the gear reducer assembly <NUM>. At least one form also includes a manually-actuatable "bailout" assembly <NUM> that is configured to enable the clinician to manually retract the longitudinally movable drive member <NUM> should the motor <NUM> become disabled. The bailout assembly <NUM> may include a lever or bailout handle assembly <NUM> that is configured to be manually pivoted into ratcheting engagement with teeth <NUM> also provided in the drive member <NUM>. Thus, the clinician can manually retract the drive member <NUM> by using the bailout handle assembly <NUM> to ratchet the drive member <NUM> in the proximal direction "PD". <CIT>, entitled POWERED SURGICAL CUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM, discloses bailout arrangements and other components, arrangements and systems that may also be employed with the various instruments disclosed herein.

Turning now to <FIG> and <FIG>, the interchangeable shaft assembly <NUM> includes a surgical end effector <NUM> that comprises an elongate channel <NUM> that is configured to operably support a staple cartridge <NUM> therein. The end effector <NUM> may further include an anvil <NUM> that is pivotally supported relative to the elongate channel <NUM>. The interchangeable shaft assembly <NUM> may further include an articulation joint <NUM> and an articulation lock <NUM> which can be configured to releasably hold the end effector <NUM> in a desired position relative to a shaft axis SA. As can be seen in <FIG>, the interchangeable shaft assembly <NUM> can further include a proximal housing or nozzle <NUM> comprised of nozzle portions <NUM> and <NUM>.

The interchangeable shaft assembly <NUM> can further include a closure system or closure member assembly <NUM> which can be utilized to close and/or open the anvil <NUM> of the end effector <NUM>. The shaft assembly <NUM> can include a spine <NUM> that is configured to, one, slidably support a firing member therein and, two, slidably support the closure member assembly <NUM> which extends around the spine <NUM>. As can be seen in <FIG>, a distal end <NUM> of spine <NUM> terminates in an upper lug mount feature <NUM> and in a lower lug mount feature <NUM>. The upper lug mount feature <NUM> is formed with a lug slot <NUM> therein that is adapted to mountingly support an upper mounting link <NUM> therein. Similarly, the lower lug mount feature <NUM> is formed with a lug slot <NUM> therein that is adapted to mountingly support a lower mounting link <NUM> therein. The upper mounting link <NUM> includes a pivot socket <NUM> therein that is adapted to rotatably receive therein a pivot pin <NUM> that is formed on a channel cap or anvil retainer <NUM> that is attached to a proximal end portion <NUM> of the elongate channel <NUM>. The lower mounting link <NUM> includes lower pivot pin <NUM> that adapted to be received within a pivot hole <NUM> formed in the proximal end portion <NUM> of the elongate channel <NUM>. The lower pivot pin <NUM> is vertically aligned with the pivot socket <NUM> to define an articulation axis AA about which the surgical end effector <NUM> may articulate relative to the shaft axis SA.

In the illustrated example, the surgical end effector <NUM> is selectively articulatable about the articulation axis AA by an articulation system <NUM>. In one form, the articulation system <NUM> includes proximal articulation driver <NUM> that is pivotally coupled to an articulation link <NUM>. As can be most particularly seen in <FIG>, an offset attachment lug <NUM> is formed on a distal end <NUM> of the proximal articulation driver <NUM>. A pivot hole <NUM> is formed in the offset attachment lug <NUM> and is configured to pivotally receive therein a proximal link pin <NUM> formed on the proximal end <NUM> of the articulation link <NUM>. A distal end <NUM> of the articulation link <NUM> includes a pivot hole <NUM> that is configured to pivotally receive therein a channel pin <NUM> formed on the proximal end portion <NUM> of the elongate channel <NUM>. Thus, axial movement of proximal articulation driver <NUM> will thereby apply articulation motions to the elongate channel <NUM> to thereby cause the surgical end effector <NUM> to articulate about the articulation axis AA relative to the spine assembly <NUM>. In various circumstances, the proximal articulation driver <NUM> can be held in position by an articulation lock <NUM> when the proximal articulation driver <NUM> is not being moved in the proximal or distal directions.

In various circumstances, the spine <NUM> can comprise a proximal end <NUM> which is rotatably supported in a chassis <NUM>. In one arrangement, for example, the proximal end <NUM> of the spine <NUM> has a thread <NUM> formed thereon for threaded attachment to a spine bearing <NUM> configured to be supported within the chassis <NUM>. Such an arrangement facilitates rotatable attachment of the spine <NUM> to the chassis <NUM> such that the spine <NUM> may be selectively rotated about a shaft axis SA relative to the chassis <NUM>.

Referring primarily to <FIG>, the interchangeable shaft assembly <NUM> includes a closure shuttle <NUM> that is slidably supported within the chassis <NUM> such that it may be axially moved relative thereto. The closure shuttle <NUM> includes a pair of proximally-protruding hooks <NUM> that are configured for attachment to the attachment pin <NUM> (<FIG> and <FIG>) that is attached to the second closure link <NUM> as will be discussed in further detail below. In at least one example, the closure member assembly <NUM> comprises a proximal closure member segment <NUM> that has a proximal end <NUM> that is coupled to the closure shuttle <NUM> for relative rotation thereto. For example, a U shaped connector <NUM> is inserted into an annular slot <NUM> in the proximal end <NUM> of the proximal closure member segment <NUM> and is retained within vertical slots <NUM> in the closure shuttle <NUM>. Such an arrangement serves to attach the proximal closure tube segment <NUM> to the closure shuttle <NUM> for axial travel therewith while enabling the proximal closure tube segment <NUM> to rotate relative to the closure shuttle <NUM> about the shaft axis SA. A closure spring <NUM> is journaled on the proximal closure tube segment <NUM> and serves to bias the proximal closure tube segment <NUM> in the proximal direction "PD" which can serve to pivot the closure trigger <NUM> into the unactuated position when the shaft assembly is operably coupled to the handle <NUM>.

In at least one form, the interchangeable shaft assembly <NUM> may further include an articulation joint <NUM>. Other interchangeable shaft assemblies, however, may not be capable of articulation. As can be seen in <FIG>, for example, a distal closure member or distal closure tube segment <NUM> is coupled to the distal end of the proximal closure member or proximal closure tube segment <NUM>. The articulation joint <NUM> includes a double pivot closure sleeve assembly <NUM>. According to various forms, the double pivot closure sleeve assembly <NUM> includes an end effector closure tube <NUM> having upper and lower distally projecting tangs <NUM>, <NUM>. An upper double pivot link <NUM> includes upwardly projecting distal and proximal pivot pins that engage respectively an upper distal pin hole in the upper proximally projecting tang <NUM> and an upper proximal pin hole in an upper distally projecting tang <NUM> on the distal closure tube segment <NUM>. A lower double pivot link <NUM> includes upwardly projecting distal and proximal pivot pins that engage respectively a lower distal pin hole in the lower proximally projecting tang <NUM> and a lower proximal pin hole in the lower distally projecting tang <NUM>. See <FIG> and <FIG>. As will be discussed in further detail below, the closure tube assembly <NUM> is translated distally (direction "DD") to close the anvil <NUM>, for example, in response to the actuation of the closure trigger <NUM>. The anvil <NUM> is opened by proximally translating the closure tube assembly <NUM> which causes the end effector closure sleeve to interact with the anvil <NUM> and pivot it to an open position.

As was also indicated above, the interchangeable shaft assembly <NUM> further includes a firing member <NUM> that is supported for axial travel within the shaft spine <NUM>. The firing member includes an intermediate firing shaft portion <NUM> that is configured for attachment to a distal cutting portion or knife bar <NUM>. The intermediate firing shaft portion <NUM> may include a longitudinal slot <NUM> in the distal end thereof which can be configured to receive a tab <NUM> on the proximal end of the distal knife bar <NUM>. The longitudinal slot <NUM> and the proximal end tab <NUM> can be sized and configured to permit relative movement therebetween and can comprise a slip joint. The slip joint1914 can permit the intermediate firing shaft portion <NUM> of the firing drive to be moved to articulate the end effector <NUM> without moving, or at least substantially moving, the knife bar <NUM>. Once the end effector <NUM> has been suitably oriented, the intermediate firing shaft portion <NUM> can be advanced distally until a proximal sidewall of the longitudinal slot <NUM> comes into contact with the tab <NUM> in order to advance the knife bar <NUM> and fire the staple cartridge <NUM> positioned within the channel <NUM>. The knife bar <NUM> includes a knife portion <NUM> that includes a blade or tissue cutting edge <NUM> and includes an upper anvil engagement tab <NUM> and lower channel engagement tabs <NUM>. Various firing member configurations and operations are disclosed in various other references mentioned herein.

As can be seen in <FIG>, the shaft assembly <NUM> further includes a switch drum <NUM> that is rotatably received on the closure tube <NUM>. The switch drum <NUM> comprises a hollow shaft segment <NUM> that has a shaft boss formed thereon for receive an outwardly protruding actuation pin therein. In various circumstances, the actuation pin extends through a longitudinal slot provided in the lock sleeve to facilitate axial movement of the lock sleeve when it is engaged with the articulation driver. A rotary torsion spring <NUM> is configured to engage the boss on the switch drum <NUM> and a portion of the nozzle housing <NUM> to apply a biasing force to the switch drum <NUM>. The switch drum <NUM> can further comprise at least partially circumferential openings <NUM> defined therein which can be configured to receive circumferential mounts extending from the nozzle halves <NUM>, <NUM> and permit relative rotation, but not translation, between the switch drum <NUM> and the proximal nozzle <NUM>. The mounts also extend through openings <NUM> in the proximal closure tube segment <NUM> to be seated in recesses <NUM> in the spine shaft <NUM>. Rotation of the switch drum <NUM> about the shaft axis SA will ultimately result in the rotation of the actuation pin and the lock sleeve between its engaged and disengaged positions. In one arrangement, the rotation of the switch drum <NUM> may be linked to the axial advancement of the closure tube or closure member. For example, when the closure tube is in its proximal-most position corresponding to a "jaws open" position, the closure tube segment <NUM> will have positioned the switch drum <NUM> so as to link the articulation system with the firing drive system. When, the closure tube has been moved to its distal position corresponding to a "jaws closed" position, the closure tube has rotated the switch drum <NUM> to a position wherein the articulation system is delinked from the firing drive system.

As also illustrated in <FIG>, the shaft assembly <NUM> can comprise a slip ring assembly <NUM> which can be configured to conduct electrical power to and/or from the end effector <NUM> and/or communicate signals to and/or from the end effector <NUM>, for example. The slip ring assembly <NUM> can comprise a proximal connector flange <NUM> that is mounted to a chassis flange <NUM> that extends from the chassis <NUM> and a distal connector flange that is positioned within a slot defined in the shaft housings. The proximal connector flange <NUM> can comprise a first face and the distal connector flange can comprise a second face which is positioned adjacent to and movable relative to the first face. The distal connector flange can rotate relative to the proximal connector flange <NUM> about the shaft axis SA. The proximal connector flange <NUM> can comprise a plurality of concentric, or at least substantially concentric, conductors defined in the first face thereof. A connector can be mounted on the proximal side of the connector flange and may have a plurality of contacts wherein each contact corresponds to and is in electrical contact with one of the conductors. Such an arrangement permits relative rotation between the proximal connector flange <NUM> and the distal connector flange while maintaining electrical contact therebetween. The proximal connector flange <NUM> can include an electrical connector <NUM> which can place the conductors in signal communication with a shaft circuit board <NUM> mounted to the shaft chassis <NUM>, for example. In at least one instance, a wiring harness comprising a plurality of conductors can extend between the electrical connector <NUM> and the shaft circuit board <NUM>. The electrical connector <NUM> may extend proximally through a connector opening <NUM> defined in the chassis mounting flange <NUM>.

As discussed above, the shaft assembly <NUM> can include a proximal portion which is fixably mounted to the handle <NUM> and a distal portion which is rotatable about a longitudinal axis. The rotatable distal shaft portion can be rotated relative to the proximal portion about the slip ring assembly <NUM>, as discussed above. The distal connector flange of the slip ring assembly <NUM> can be positioned within the rotatable distal shaft portion. Moreover, further to the above, the switch drum <NUM> can also be positioned within the rotatable distal shaft portion. When the rotatable distal shaft portion is rotated, the distal connector flange and the switch drum <NUM> can be rotated synchronously with one another. In addition, the switch drum <NUM> can be rotated between a first position and a second position relative to the distal connector flange. When the switch drum <NUM> is in its first position, the articulation drive system may be operably disengaged from the firing drive system and, thus, the operation of the firing drive system may not articulate the end effector <NUM> of the shaft assembly <NUM>. When the switch drum <NUM> is in its second position, the articulation drive system may be operably engaged with the firing drive system and, thus, the operation of the firing drive system may articulate the end effector <NUM> of the shaft assembly <NUM>. When the switch drum <NUM> is moved between its first position and its second position, the switch drum <NUM> is moved relative to distal connector flange. In various instances, the shaft assembly <NUM> can comprise at least one sensor configured to detect the position of the switch drum <NUM>.

Referring again to <FIG>, the chassis <NUM> includes at least one, and preferably two, tapered attachment portions <NUM> formed thereon that are adapted to be received within corresponding dovetail slots <NUM> formed within a distal attachment flange portion <NUM> of the frame <NUM>. Each dovetail slot <NUM> may be tapered or, stated another way, be somewhat V-shaped to seatingly receive the attachment portions <NUM> therein. As can be further seen in <FIG>, a shaft attachment lug <NUM> is formed on the proximal end of the intermediate firing shaft <NUM>. As will be discussed in further detail below, when the interchangeable shaft assembly <NUM> is coupled to the handle <NUM>, the shaft attachment lug <NUM> is received in a firing shaft attachment cradle <NUM> formed in the distal end <NUM> of the longitudinal drive member <NUM>.

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

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

As can be most particularly seen in <FIG>, the lock yoke <NUM> includes at least one and preferably two lock hooks <NUM> that are adapted to contact corresponding lock lug portions <NUM> that are formed on the closure shuttle <NUM>. When the closure shuttle <NUM> is in an unactuated position (i.e., the first drive system <NUM> is unactuated and the anvil <NUM> is open), the lock yoke <NUM> may be pivoted in a distal direction to unlock the interchangeable shaft assembly <NUM> from the housing <NUM>. When in that position, the lock hooks <NUM> do not contact the lock lug portions <NUM> on the closure shuttle <NUM>. However, when the closure shuttle <NUM> is moved to an actuated position (i.e., the first drive system <NUM> is actuated and the anvil <NUM> is in the closed position), the lock yoke <NUM> is prevented from being pivoted to an unlocked position. Stated another way, if the clinician were to attempt to pivot the lock yoke <NUM> to an unlocked position or, for example, the lock yoke <NUM> was in advertently bumped or contacted in a manner that might otherwise cause it to pivot distally, the lock hooks <NUM> on the lock yoke <NUM> will contact the lock lugs <NUM> on the closure shuttle <NUM> and prevent movement of the lock yoke <NUM> to an unlocked position.

Attachment of the interchangeable shaft assembly <NUM> to the handle <NUM> will now be described. To commence the coupling process, the clinician may position the chassis <NUM> of the interchangeable shaft assembly <NUM> above or adjacent to the distal attachment flange <NUM> of the frame <NUM> such that the tapered attachment portions <NUM> formed on the chassis <NUM> are aligned with the dovetail slots <NUM> in the frame <NUM>. The clinician may then move the shaft assembly <NUM> along an installation axis that is perpendicular to the shaft axis SA to seat the attachment portions <NUM> in "operable engagement" with the corresponding dovetail receiving slots <NUM>. In doing so, the shaft attachment lug <NUM> on the intermediate firing shaft <NUM> will also be seated in the cradle <NUM> in the longitudinally movable drive member <NUM> and the portions of pin <NUM> on the second closure link <NUM> will be seated in the corresponding hooks <NUM> in the closure yoke <NUM>. As used herein, the term "operable engagement" in the context of two components means that the two components are sufficiently engaged with each other so that upon application of an actuation motion thereto, the components may carry out their intended action, function and/or procedure.

At least five systems of the interchangeable shaft assembly <NUM> can be operably coupled with at least five corresponding systems of the handle <NUM>. A first system can comprise a frame system which couples and/or aligns the frame or spine of the shaft assembly <NUM> with the frame <NUM> of the handle <NUM>. Another system can comprise a closure drive system <NUM> which can operably connect the closure trigger <NUM> of the handle <NUM> and the closure tube <NUM> and the anvil <NUM> of the shaft assembly <NUM>. As outlined above, the closure tube attachment yoke <NUM> of the shaft assembly <NUM> can be engaged with the pin <NUM> on the second closure link <NUM>. Another system can comprise the firing drive system <NUM> which can operably connect the firing trigger <NUM> of the handle <NUM> with the intermediate firing shaft <NUM> of the shaft assembly <NUM>. As outlined above, the shaft attachment lug <NUM> can be operably connected with the cradle <NUM> of the longitudinal drive member <NUM>. Another system can comprise an electrical system which can signal to a controller in the handle <NUM>, such as microcontroller, for example, that a shaft assembly, such as shaft assembly <NUM>, for example, has been operably engaged with the handle <NUM> and/or, two, conduct power and/or communication signals between the shaft assembly <NUM> and the handle <NUM>. For instance, the shaft assembly <NUM> can include an electrical connector <NUM> that is operably mounted to the shaft circuit board <NUM>. The electrical connector <NUM> is configured for mating engagement with a corresponding electrical connector <NUM> on the handle control board <NUM>. The fifth system may consist of the latching system for releasably locking the shaft assembly <NUM> to the handle <NUM>.

Referring now to <FIG>, the anvil <NUM> in the illustrated example includes an anvil body <NUM> that terminates in anvil mounting portion <NUM>. The anvil mounting portion <NUM> is movably or pivotably supported on the elongate channel <NUM> for selective pivotal travel relative thereto about a fixed anvil pivot axis PA that is transverse to the shaft axis SA. In the illustrated arrangement, a pivot member or anvil trunnion <NUM> extends laterally out of each lateral side of the anvil mounting portion <NUM> to be received in a corresponding trunnion cradle <NUM> formed in the upstanding walls <NUM> of the proximal end portion <NUM> of the elongate channel <NUM>. The anvil trunnions <NUM> are pivotally retained in their corresponding trunnion cradle <NUM> by the channel cap or anvil retainer <NUM>. The channel cap or anvil retainer <NUM> includes a pair of attachment lugs that are configured to be retainingly received within corresponding lug grooves or notches formed in the upstanding walls <NUM> of the proximal end portion <NUM> of the elongate channel <NUM>.

Referring to <FIG>, <FIG>, in at least one arrangement, the distal closure member or end effector closure tube <NUM> employs two axially offset, proximal and distal positive jaw opening features <NUM> and <NUM>. In <FIG>, the proximal positive jaw opening feature <NUM> is located on the right side (as viewed by a user of the tool assembly) of the shaft axis SA. The positive jaw opening features <NUM>, <NUM> are configured to interact with corresponding relieved areas <NUM>, <NUM> and stepped portions formed on the anvil mounting portion <NUM>. Other jaw opening arrangements may be employed.

<FIG> and <FIG> illustrate one form of an anvil <NUM> that includes an elongate anvil body portion <NUM> that terminates in an mounting portion <NUM> that is configured to interact with the end effector closure sleeve <NUM> to minimize the amount of resultant forces experienced by the end effector closure tube <NUM> as the anvil <NUM> is moved from a fully open position to a closed position and ultimately an over-closed position. The anvil body portion <NUM> includes a staple-forming undersurface <NUM> that has a series of anvil forming pockets (not shown) formed therein. An elongate slot <NUM> extends through the body portion <NUM> and the mounting portion <NUM> to facilitate passage of the knife portion or "firing member" <NUM> therethrough. In addition, an anvil cover <NUM> is attached to the anvil body <NUM> to cover the slot <NUM>. In various circumstances, the anvil mounting portion <NUM> comprises anvil cam surface <NUM> formed thereon. The anvil cam surface <NUM> is bisected or otherwise split by the elongate slot <NUM>. As can be seen in <FIG> and <FIG>, a proximal end portion <NUM> of the anvil cover <NUM> is oriented at an angle that corresponds to the angle/orientation of the anvil cam surfaces <NUM>. <FIG> and <FIG> illustrate the anvil <NUM> in a fully open position. As can be seen in <FIG>, the distal or end effector closure tube <NUM> is in its proximal most position when the "second jaw" or anvil <NUM> is in its fully open position. When in that position, a cam surface <NUM> formed on the distal end <NUM> of the end effector closure tube <NUM> is not applying any closure forces to the cam closure surfaces <NUM>. As the end effector closure tube <NUM> is moved distally, the cam surface <NUM> on the end effector closure tube <NUM> contacts the cam closure surfaces <NUM> on the anvil mounting portion <NUM> and a corresponding closure surface <NUM> on the proximal end portion <NUM> of the anvil cover <NUM> to pivot the anvil <NUM> into a "closed" position. <FIG> and <FIG> illustrate the positions of the end effector closure tube <NUM> and the anvil <NUM> when the anvil <NUM> is in the closed position.

As the end effector closure tube <NUM> continues to be advanced distally to apply additional closure motions to the anvil to ultimately move the anvil to an "over-closed" position, the end effector closure tube may experience significant stress which may, overtime, cause the end effector closure tube to become elongated vertically (when viewed from an end) or, stated another way, become somewhat oval in shape which may ultimately lead to failure or otherwise detrimentally effect the ability to attain a fully closed position. It is axiomatic that when a thin-walled tube or cylinder is subjected to internal pressure, a "hoop" and longitudinal stress are produced in the wall of the tube. This hoop stress is acting circumferential and perpendicular to the axis and radius of the cylinder wall. Such hoop stress may be calculated as: <MAT> where:.

End effector closure tubes with various tube wall configurations have been developed.

<FIG> illustrate one form of an end effector closure tube <NUM>. The closure tube <NUM> comprises an external surface <NUM> and an internal wall surface <NUM>. In at least one form, the closure tube <NUM> comprises a constant internal diameter ID and a constant external diameter OD to define a wall thickness CT that is uniform or constant throughout a length of the closure tube <NUM> or at least the portion of the closure tube that is configured to interface with the end effector jaws such as the anvil <NUM> and the elongate channel <NUM>.

Returning now to <FIG>, in at least one arrangement, when the anvil <NUM> is in the "closed position", a clearance distance "CD" may be observed between the staple-forming underside <NUM> of the anvil body <NUM> and the cartridge deck surface of a cartridge that is supported within the elongate channel <NUM> when no tissue is clamped between the anvil <NUM> and the cartridge. <FIG> is a cross-sectional view taken along line <NUM>-<NUM> in <FIG> across the closure cam surfaces <NUM> as well as through a distal end portion of the end effector closure tube <NUM> as well as the anvil mounting portion <NUM> and the proximal end portion of the elongate channel <NUM>. As can be seen in that Figure, various closure forces CF are applied to the anvil <NUM> and elongate channel <NUM> by the end effector closure tube <NUM>. For example, closure forces CF are applied onto the closure cam surfaces <NUM> and the proximal end portion <NUM> of the anvil cap <NUM> as well as onto the elongate channel <NUM>.

In the example illustrated in <FIG>, the anvil mounting portion <NUM> is formed to establish a plurality of discrete load transfer locations that are configured to be contacted by the inner surface <NUM> of the end effector closure tube <NUM> when the end effector closure tube <NUM> is in the position corresponding to the closed position of the anvil <NUM>. In at least one arrangement, at least two discrete load transfer locations are located on each side of a vertical plane VP that bisects the anvil <NUM> when the anvil <NUM> is in the closed position. For example, in <FIG>, a first right load transfer location or edge 2070R, a second right load transfer location or edge 2072R, a third right load transfer location or edge 2074R and a fourth right load transfer location or edge 2076R are formed on a right side of the vertical plane VP. Similarly, a first left load transfer location or edge <NUM>, a second left load transfer location or edge <NUM>, a third left load transfer location or edge <NUM> and a fourth left load transfer location or edge <NUM> are formed on a left side of the vertical plane VP. As used in this context, the term "at least two discrete load transfer locations" means that the load transfer locations are formed relative to each other so that a space or clearance is formed between the portion of the anvil mounting portion <NUM> extending between the load transfer locations and the inner surface <NUM> of the end effector closure tube <NUM>.

For example, a first amount of clearance CR<NUM> is formed between the inner surface <NUM> of the end effector closure tube <NUM> extending between the first right load transfer location 2070R and the second right load transfer location 2072R. A second amount of clearance CR<NUM> is formed between the inner surface of the end effector closure tube <NUM> extending between the third right load transfer location 2072R and the third right load transfer location 2074R. A third amount of clearance CR<NUM> is formed between the third right load transfer location 2074R and the fourth right load transfer location 2076R. A first amount of clearance CL<NUM> is formed between the inner surface of the end effector closure tube extending between the first left load transfer location <NUM> and the second left load transfer location <NUM>. A second amount of clearance CL<NUM> is formed between the inner surface <NUM> of the end effector closure tube extending between the second left load transfer location <NUM> and the third left load transfer location <NUM>. A third amount of clearance CL<NUM> is formed between the third left load transfer location <NUM> and the fourth left load transfer location <NUM>. In at least one arrangement, the closure forces CF applied to the closure cam surfaces <NUM>, as well as the proximal portion <NUM> of the anvil cap <NUM> may be evenly distributed between the first right load transfer location 2070R and the first left load transfer location <NUM>. Likewise, the closure forces CF applied to the elongate channel <NUM> may be evenly distributed between the fourth right load transfer location 2076R and the fourth left load transfer location <NUM>, for example.

In at least one arrangement, at least two right load transfer locations 2070R, 2072R and at least two left load transfer locations <NUM>, <NUM> are located on one side of a horizontal plane HP that bisects the end effector <NUM>. As illustrated in <FIG>, the two right load transfer locations 2070R, 2072R are located on an opposite side of vertical plane VP from the two left load transfer locations <NUM>, <NUM>. Also in at least one arrangement, the third right load transfer location 2074R and the fourth right load transfer location 2076R are located on an opposite side of the horizontal plane HP from the first right load transfer location 2070R and the second right load transfer location 2072R. Similarly, third left load transfer location <NUM> and the fourth left load transfer location <NUM> are located on a opposite side of the horizontal plane HP from the first left load transfer location <NUM> and the second left load transfer location <NUM>. The right load transfer locations 2074R, 2076R are located on an opposite side of vertical plane VP from the two left load transfer locations <NUM>, <NUM>. As can be seen in <FIG> and <FIG>, the load transfer locations may be formed by scalloped or relieved areas <NUM>, <NUM>, <NUM> so that the load transfer locations comprise corners formed from adjoining surfaces. Other load transfer location shapes are contemplated.

<FIG> and <FIG> illustrate the anvil <NUM> and the end effector closure tube <NUM> in an "over-closed" state that is created as the end effector closure tube <NUM> is advanced further distally after the anvil <NUM> has attained the closed position. In at least one example, the anvil <NUM> is in an "over-closed state" when a distal end portion <NUM> of the body portion <NUM> of the anvil <NUM> is in contact with the cartridge deck of the staple cartridge that is operably supported with the elongate channel <NUM>. Continued distal advancement of the end effector closure tube <NUM> after the anvil <NUM> has attained the closed position may significantly increase the hoop stress formed in the end effector closure tube <NUM> which may cause the end effector closure tube to effectually fail or vertically elongate which can detrimentally effect the proper closure of the anvil when used in future applications. As be seen in <FIG>, the first right amount of clearance CR<NUM> and the first left amount of clearance CLi may each have a clearance width CW<NUM> that is located on a common side of the horizontal plane HP. The second right amount of clearance CR<NUM>, and the second left amount of clearance CL<NUM> each span across the horizontal plane HP. Stated another way, portions of the second right amount of clearance CR<NUM> are located on each side of the horizontal plane HP and portions of the second left amount of clearance CL<NUM> are located on each side of the horizontal plane HP.

Forming at least two discrete load transfer locations located on each side of the vertical plane may reduce the amount of detrimental hoop stresses established in the end effector closure tube <NUM> as it is distally moved into the over-closed position. By forming at least three load transfer locations located on each side of the vertical plane may further reduce the amount of detrimental hoop stresses established in the end effector closure tube <NUM> as it is distally moved into the over-closed position. Forming at least four load transfer locations located on each side of the vertical plane may further reduce the amount of detrimental hoop stresses established in the end effector closure tube <NUM> as it is distally moved into the over-closed position. Such arrangements therefor enable the end effector closure tube <NUM> to be made with a constant wall thickness as described above, which may reduce the amount of manufacturing costs associated with manufacturing the end effector closure tube.

<FIG> illustrate an alternative anvil <NUM>' that is substantially identical to anvil <NUM> described above expect for the differences discussed below. As can be seen in <FIG>, the anvil mounting portion <NUM>' is formed with continuous arcuate anvil camming surfaces <NUM>' that are not interrupted by any load transfer locations. <FIG> and <FIG> illustrate the anvil <NUM>' in a fully open position. As can be seen in <FIG>, the end effector closure tube <NUM>' is in its proximal most position when the "second jaw" or anvil <NUM>' is in its fully open position. When in that position, the end effector closure tube <NUM>' is not applying any closure forces to the cam closure surfaces <NUM>'.

<FIG> illustrates one form of an end effector closure tube <NUM>' that may be identical to the end effector closure tube <NUM> described above, except for the differences noted below. The end effector closure tube <NUM>' comprises an external surface <NUM>' and an internal wall surface <NUM>'. In at least one form, the closure tube <NUM>' has a constant wall thickness WT<NUM> except for a segment As of the wall located at the top of the end effector closure tube <NUM>'that has a thicker wall thickness WT<NUM> that is greater than WT<NUM>. Such arrangement forms a single load transfer location <NUM>'.

<FIG> and <FIG> illustrate the positions of the end effector closure tube <NUM>' and the anvil <NUM>' when the anvil <NUM>' is in the closed position. As can be seen in <FIG>, as the end effector closure tube <NUM>' is moved distally, the load transfer location <NUM>' on the end effector closure tube <NUM>' contacts the cam surface <NUM> on the proximal portion <NUM> of the anvil cap <NUM>. The end effector closure tube <NUM>' also contacts portions of the elongate channel <NUM> on each side of the vertical plane VP that bisects the end effector. The load transfer location <NUM>' may span across the entire cam surface <NUM> to contact an upper portion of the cam surfaces <NUM>' on each side of the vertical plane VP as shown in <FIG>. When in the closed position shown in <FIG> and <FIG>, such arrangement serves to form a space <NUM> between the corresponding portions of the inner surface <NUM>' of the end effector closure tube <NUM>' and the cam surfaces <NUM>' of the anvil mounting portion <NUM>' as shown in <FIG>. The spaces <NUM> each extend from the load transfer location <NUM>' and the area wherein the inner surface <NUM>' contacts the elongate channel <NUM> (space distance SD). Thus, when the anvil <NUM>' is moved to a closed position, there is a discrete first load transfer location <NUM>' located on one side of a horizontal plane HP and two discrete load transfer locations 2072R', <NUM>' locations located on an opposite side of the horizontal plane HP. The discrete first load transfer location <NUM>' is separated from each of the discrete load transfer locations 2072R', <NUM>' by spaces <NUM> when the anvil <NUM>' is in the closed position. As can also be seen in <FIG>, the load transfer locations 2072R', <NUM>' are located on opposite sides of the vertical plane VP.

<FIG> and <FIG> illustrate the interrelationship between the end effector closure tube <NUM>' and the anvil <NUM>' when the end effector closure tube <NUM>' has moved the anvil <NUM>' in an over-closed orientation. As can be seen in <FIG>, when in the over-closed position, the end effector closure tube <NUM>' contacts the anvil <NUM>' and the elongate channel <NUM> to form a discrete load transfer location <NUM>' that is separated from discrete load transfer locations 2074R', <NUM>' by spaces 3079R, <NUM>. The discrete load transfer location 2074R' is separated by the discrete load transfer location 2076R' by a space 3081R and the discrete load transfer location <NUM>' is separated from a discrete load transfer location <NUM>' by a space <NUM>. Thus, in this arrangement, at least one discrete load transfer location (<NUM>') spans a vertical plane VP that bisects the end effector and at least two discrete load transfer locations span a horizontal plane HP that bisects the end effector. In addition, at least one discrete load transfer location is located on each side of the horizontal plane HP and at least one discrete load transfer location is located on each side of the vertical plane VP. Such arrangement of load transfer locations in the above manner may help to prevent the vertical elongation of the end effector closure tube <NUM>'.

<FIG> illustrate an alternative anvil <NUM>" that is substantially identical to anvil <NUM> described above expect for the differences discussed below. As can be seen in <FIG>, the anvil mounting portion <NUM>" is formed with an arcuate anvil camming surface <NUM>" and right and left notched or recessed portions <NUM>". <FIG> and <FIG> illustrate the anvil <NUM>" in a fully open position. As can be seen in <FIG>, the end effector closure tube <NUM>" is in its proximal most position when the "second jaw" or anvil <NUM>" is in its fully open position. When in that position, the end effector closure tube <NUM>" is not applying any closure forces to the cam closure surfaces <NUM>". <FIG> illustrates one form of an end effector closure tube <NUM>" that may be identical to the end effector closure tube <NUM> described above, except for the differences noted below. The end effector closure tube <NUM>" comprises an external surface <NUM>" and an internal wall surface <NUM>". In at least one form, the closure tube <NUM>" has a first wall thickness WT<NUM>, a second wall thickness WT<NUM>, a third wall thickness WT<NUM>, and a fourth wall thickness WT<NUM> that are arranged as shown in <FIG>. In at least one arrangement, for example, WT<NUM> < WT<NUM> < WT<NUM> ≤ WT<NUM>. In some cases, WT<NUM> > WT<NUM>. The portion of the end effector closure tube <NUM>" that has a wall thickness corresponding to WT<NUM> forms a load transfer location <NUM>". In the illustrated arrangement, for example, the load transfer location <NUM>" spans across a vertical plane VP that bisects the end effector closure tube <NUM>". The portions of the end effector closure tube <NUM>" that have a wall thickness WT<NUM> form load transfer locations 2072R", <NUM>". In at least one arrangement as shown in <FIG>, the load transfer locations 2072R", <NUM>" span across a horizontal plane HP that bisects the end effector closure tube <NUM>".

Referring now to <FIG> and <FIG>, as the end effector closure tube <NUM>" is moved distally, the load transfer location <NUM>" contacts the cam surface <NUM> on the proximal portion <NUM> of the anvil cap <NUM>. The load transfer locations 2072R", <NUM>" also contact corresponding portions of the anvil mounting portion <NUM>". Also portions of the end effector closure tube <NUM>" form load transfer locations 2074R", <NUM>" that contact corresponding portions of the elongate channel <NUM> to move the anvil <NUM>" to the closed position shown in <FIG> and <FIG>. When in the closed position shown in <FIG> and <FIG>, such arrangement serves to form a space <NUM>", <NUM>" between the corresponding portions of the inner surface <NUM>" of the end effector closure tube <NUM>" and the cam surfaces <NUM>" of the anvil mounting portion <NUM>" as shown in <FIG>. The spaces <NUM>" are located between the load transfer location <NUM>" and the load transfer locations 2072R", <NUM>". The spaces <NUM>" are located between the load transfer locations 2072R", <NUM>" and the load transfer locations 2074R, <NUM>" as shown in <FIG>.

<FIG> and <FIG> illustrate the interrelationship between the end effector closure tube <NUM>" and the anvil <NUM>" when the end effector closure tube <NUM>" has moved the anvil <NUM>" into an over-closed orientation. As can be seen in <FIG>, in addition to the load transfer locations <NUM>", 2072R", <NUM>", 2074R", <NUM>", discrete load transfer locations 2076R", <NUM>" are formed by the edge of the recessed portions <NUM>"formed on the anvil mounting portion <NUM>". Such discrete load transfer locations 2076R", <NUM>" are separated from the corresponding discrete load transfer locations 2072R". <NUM>" by corresponding spaces <NUM>". The provision of the discrete load transfer locations in the above manner may help to prevent the vertical elongation of the end effector closure tube <NUM>".

When using an end effector <NUM> of the type and construction described herein, a clinician manipulates the first and second jaws (the anvil <NUM> and the elongate channel <NUM> that has a surgical staple cartridge operably mounted therein), to capture the tissue to be cut and stapled (the "target tissue") therebetween. As can be seen in <FIG> and <FIG>, for example, a surgical staple cartridge <NUM> comprises a cartridge body <NUM> that is configured to be removably supported within the elongate channel <NUM>. The cartridge body <NUM> includes an elongate cartridge slot <NUM> that extends from a proximal end <NUM> through the cartridge body <NUM> to a distal end portion <NUM> to enable the knife member or firing member <NUM> to pass therethrough. The cartridge body <NUM> further defines a cartridge deck surface <NUM> on each side of the elongate slot <NUM>. A plurality of staple cavities <NUM> are provided in the cartridge body <NUM> on each side of the elongate slot <NUM>. Each cavity <NUM> opens through the deck surface <NUM> to removably support a surgical staple or staples therein. In at least one cartridge arrangement, three lines of staple cavities <NUM> are provided on each side of the elongate slot <NUM>. The lines are formed such that the staples in a center line are staggered relative to the staples in the two adjacent outer lines. The staples are supported on staple drivers that are movably supported within each staple cavity. In at least some arrangements, the staple drivers are arranged to be contacted or "fired" upward when contacted by a cam member or camming portions associated with the knife member <NUM>, for example. In some arrangements, a wedge sled or camming sled is movably supported in the cartridge body and is adapted to be axially displaced through the cartridge body as the knife member <NUM> is axially deployed through the cartridge from the proximal end portion <NUM> to the distal end portion <NUM> of the cartridge body <NUM>. The wedge sled includes a camming member or wedge associated with each line of staple cavities so as to serially deploy the staple drivers supported therein. As the cam contacts a staple driver, the driver is driven upwardly within the staple cavity driving the staple or staples supported thereon out of the staple cavity through the clamped tissue and into forming contact with the staple-forming undersurface of the anvil. The wedge sled or camming member is located distal to the knife or tissue cutting edge of the knife or firing member <NUM>, so that the tissue is stapled prior to be severed by the tissue cutting edge.

When the clinician initially locates the target tissue between the anvil and the staple cartridge, it is important that the target tissue be located so that the knife does not cut into the target tissue unless it is first stapled. In previous anvil arrangements, tissue stops are provided on the proximal end of the anvil body to prevent the target tissue from moving proximally past the proximal most staple pockets in the staple cartridge. Such tissue stops form abrupt proximal ends that confront or face the distal end of the end effector closure tube. As the closure tube is moved distally to close the anvil, tissue extending outward from between the anvil and the cartridge occasionally will become undesirably pinned or pinched between the proximal ends of the tissue stops and the distal end of the end effector closure tube. The examples disclosed below are configured to minimize the possibility of tissue being pinched between the tissue stops and the end effector closure tube when the anvil is being moved to the closed and over-closed positions in the various manners described herein.

Turning to <FIG>, for example, the staple cartridge <NUM> includes staples (not shown) that are removably supported or stored in each of the proximal most staple cavities 4022P located in the lines of staple cavities <NUM> located in the cartridge body <NUM> on each side of the elongate slot <NUM>.

In various circumstances, In embodiments of the invention, to prevent the target tissue from being clamped proximal to the staples in the proximal most staple cavities 4022P, the anvil <NUM> includes two tissue stop members <NUM> that protrude downwardly past the staple-forming undersurface on each side of the anvil body. When the anvil is in a closed position or in an over-closed position, each of the tissue stop members <NUM> protrude downwardly on each side of the cartridge body <NUM>. <FIG> illustrates the anvil <NUM> in an open configuration. As can be seen in that Figure, each of the tissue stops <NUM> extend below the cartridge deck surface to prevent the target tissue from extending proximally past the staples in the proximal most staple cavities 4022P. As can be seen in <FIG>, <FIG>, in at least one arrangement, the tissue stops <NUM> are integrally formed with the anvil body portion <NUM>. The anvil body portion <NUM> and the proximal ends of the tissue stops <NUM> extend slightly above the corresponding camming surfaces <NUM> formed on the anvil mounting portion <NUM>. In the illustrated example, the proximal ends of the tissue stops <NUM> are segmented into an upper proximal end portion <NUM>, a lower proximal end portion <NUM> and a bottom proximal end portion <NUM>. As can also be seen in <FIG>, an angled surface or chamfer surface <NUM> is formed between the upper proximal end portion <NUM> and the camming surface <NUM> on the anvil mounting portion. An angled surface or chamfer surface <NUM> is formed between the lower proximal end portion <NUM> and the camming surface <NUM> and an angled surface or chamfer surface <NUM> is formed between the bottom proximal end portion <NUM> and the camming surface <NUM>. In the illustrated arrangement wherein scalloped or relieved areas <NUM>, <NUM>, <NUM> are formed in the anvil mounting portion <NUM>, the chamfer <NUM> corresponds to the relieved area <NUM>. The lower proximal end portion <NUM> and accompanying chamfer <NUM> correspond to relieved area <NUM> and the bottom proximal end portion <NUM> and accompanying chamfer <NUM> corresponds to relieved area <NUM>.

As discussed above, the anvil <NUM> is moved from a fully open position to the closed position and an over-closed position by the axially movable end effector closure tube <NUM>. <FIG> and <FIG> illustrate the position of the end effector closure tube <NUM> relative to the tissue stops <NUM> when the anvil <NUM> is in the closed position. As can be seen in <FIG>, the upper proximal end portion <NUM> and accompanying chamfer <NUM> are approximately parallel to a corresponding portion of a distal end <NUM> of the end effector closure tube <NUM>. To reduce a possibility of tissue being inadvertently pinched between the tissue stops <NUM> and the distal end <NUM> of the end effector closure tube <NUM>, the lower proximal end portion <NUM> and the bottom proximal end portion <NUM> of the tissue stop2040 and the corresponding chamfers <NUM> and <NUM> angle away from the distal end <NUM> of the end effector closure tube <NUM>. This arrangement has the practical effect of increasing a distance between the portion of the tissue stop and the end effector closure tube that may most likely encounter adjacent tissue.

<FIG> is an enlarged view of a portion of the end effector depicted in <FIG> wherein the anvil <NUM> is in a closed position. When in that position, the upper proximal end portion <NUM> of each tissue stops <NUM> is located a first tissue distance TD<NUM> from the distal end 3051of the end effector closure tube <NUM>. The bottom proximal end portion <NUM> of each tissue stop <NUM> is located a second tissue distance TD<NUM> from the distal end <NUM> of the end effector closure tube <NUM>. As can be seen in that Figure, TD<NUM> > TD<NUM>. <FIG> and <FIG> depict the anvil <NUM> in an over-closed position. The first tissue distance TD<NUM>' between the upper proximal end portion <NUM> of each tissue stop <NUM> is still slightly less than the second tissue distance TD<NUM>' between the bottom proximal end portion <NUM> of each tissue stop <NUM> and the distal end <NUM> of the end effector closure tube <NUM> which will still reduce the likelihood of tissue pinch therebetween. Also, the inclusion of the chamfered surfaces <NUM>, <NUM> and <NUM> may help to lessen the likelihood of pinching tissue between the tissue stops <NUM> and the distal end <NUM> of the end effector closure tube <NUM> when the anvil <NUM> is moved to the closed and over-closed positions. In at least one example, TD<NUM> and/or TD<NUM>' may be approximately ten thousands of an inch (<NUM>) to approximately twenty-five thousands of an inch (<NUM>). However, other gaps may be attained. The person of ordinary skill in the art will appreciate that the above-described tissue stop configurations will also work with other forms of end effector closure tube and closure member arrangements.

<FIG> illustrate another anvil <NUM> that is identical to anvil <NUM> described above except for the differences relating to tissue stops <NUM>. Tissue stops <NUM> may be identical to tissue stops <NUM> except that proximal end portions <NUM>, <NUM>, <NUM> of each tissue stop and the accompanying chamfer surfaces <NUM>, <NUM>, <NUM> are approximately parallel to the distal end <NUM> of the end effector closure tube <NUM>. End effector closure tube <NUM> may otherwise be identical to end effector closure tube <NUM> described above, except for the differences discussed below. <FIG> and <FIG> illustrate the anvil <NUM> in the closed position. In this arrangement, an area that may otherwise be susceptible to pinching tissue is the edge of the bottom proximal end portion <NUM> and the confronting portion of the distal end <NUM> of the end effector closure tube <NUM>. To alleviate and minimize such possibility, a relieved area <NUM> is formed in the distal end <NUM> of the end effector closure tube <NUM> that confronts or, stated another way, is opposite from the bottom proximal end <NUM> of each of the tissue stops <NUM>. In the illustrated example, each relieved area <NUM> comprises an arcuate notch <NUM> that is formed in the portion of the distal end <NUM> of the end effector closure tube <NUM> corresponding to the bottom proximal end portion <NUM> of each tissue stop <NUM>. In the illustrated arrangements, for example, the bottom proximal end portion <NUM> of each of the tissue stops <NUM> terminates in a bottom corner <NUM> and the apex or bottom <NUM> is directly across from the bottom corner <NUM> when the end effector closure tube <NUM> is in the position corresponding to the closed position of the anvil <NUM>. Other notch shapes, however, may be employed.

<FIG> is an enlarged view of a portion of the end effector depicted in <FIG> wherein the anvil <NUM> is in a closed position. When in that position, the upper proximal end portion <NUM>, the lower proximal end portion <NUM> and the bottom proximal end portion <NUM> of each tissue stop <NUM> are located a first tissue distance TD<NUM> from the distal end <NUM> of the end effector closure tube <NUM>. The bottom proximal end portion <NUM> of each tissue stop <NUM> is located a second tissue distance TD<NUM> from the apex or bottom <NUM> of the notch <NUM> in the distal end <NUM> of the end effector closure tube <NUM>. As can be seen in that Figure, TD<NUM> > TD<NUM>. <FIG> and <FIG> depict the anvil <NUM> in an over-closed position. The first tissue distance TD<NUM>' between the bottom proximal end portion <NUM> of each tissue stop <NUM> is still less than the second tissue distance TD<NUM>' between the bottom proximal end portion <NUM> of each tissue stop <NUM> and the apex <NUM> of the corresponding notch <NUM> in the distal end <NUM> of the end effector closure tube <NUM> which will still reduce the likelihood of tissue pinch therebetween. Also, the inclusion of the chamfered surfaces <NUM>, <NUM> and <NUM> may help to lessen the likelihood of pinching tissue between the tissue stops <NUM> and the distal end <NUM> of the end effector closure tube <NUM> when the anvil <NUM> is moved to the closed and over-closed positions. The person of ordinary skill in the art will appreciate that the above-described tissue stop configurations will also work with other forms of end effector closure tube and closure member arrangements.

<FIG> illustrates a previous surgical staple cartridge <NUM> that includes a cartridge body <NUM> that is configured to be removably supported within the elongate channel <NUM>. The cartridge body <NUM> includes an elongate cartridge slot <NUM> that extends from a proximal end <NUM> through the cartridge body <NUM> to a distal end portion <NUM> to enable the knife member or firing member <NUM> (<FIG>) to pass therethrough. The cartridge body <NUM> further defines a cartridge deck surface <NUM> on each side of the elongate slot <NUM>. A plurality of staple cavities <NUM> are provided in the cartridge body <NUM> on each side of the elongate slot <NUM>. Each cavity <NUM> opens through the deck surface <NUM> to removably support a surgical staple or staples therein. In at least one cartridge arrangement, three lines of staple cavities <NUM> are provided on each side of the elongate slot <NUM>. In the illustrated example, the lines are formed such that the staples in a center line are staggered relative to the staples in the two adjacent outer lines. The staples are supported on staple drivers that are movably supported within each staple cavity. In at least some arrangements, the staple drivers are arranged to be contacted or "fired" upward when contacted by a cam member or camming portions associated with the knife member <NUM>, for example. In some arrangements, a "wedge" sled or camming sled is movably supported in the cartridge body <NUM> and is adapted to be axially displaced through the cartridge body <NUM> as the knife member <NUM> is axially deployed through the cartridge from the proximal end portion <NUM> to the distal end portion <NUM> of the cartridge body <NUM>. The wedge sled includes a camming member or "wedge" associated with each line of staple cavities so as to serially deploy the staple drivers supported therein. As the corresponding wedge or cam contacts a staple driver, the driver is driven upwardly within the staple cavity thereby driving the staple or staples supported thereon out of the staple cavity through the clamped tissue and into forming contact with the staple-forming undersurface of a confronting anvil of the end effector. The wedge sled or camming member is located distal to the knife or tissue cutting edge of the knife or firing member <NUM>, so that the tissue is stapled prior to being severed by the tissue cutting edge on the knife or firing member.

Variations to the arrangement and/or geometry of staples in a staple line can affect the flexibility and sealing properties of the staple line. For example, a staple line comprised of linear aligned staples can provide a limited amount of flexibility or stretch because the staple line can flex or stretch between the linear staples. Consequently, a limited portion of the staple line (e.g., the portion between staples) is flexible. A staple line comprised of angularly-oriented staples can also flex or stretch between the staples. However, the angularly-oriented staples are also able to rotate, which provides an additional degree of stretch within the staple line. A staple line comprised of angularly-oriented staples may be capable of stretching in excess of <NUM>%, for example. In certain instances, a staple line comprised of angularly-oriented staples can stretch at least <NUM>% or at least <NUM>%, for example. The arrangement of staples includes the relative orientation of the staples and the spacing between the staples, for example. The geometry of the staples includes the size and shape of the staples, for example. The flexibility and sealing properties of a staple line can change at longitudinal and/or lateral positions based on the arrangement and/or geometry of the staples. In certain instances, it is desirable to alter the flexibility and/or sealing properties of a staple line at one or more locations along the staple line. For example, it can be desirable to maximize the flexibility of the staple line or a portion thereof. Additionally or alternatively, it can be desirable to minimize the flexibility of the staple line or a portion thereof. It can also be desirable to maximize the sealing properties of the staple line or a portion thereof. Additionally or alternatively, it can be desirable to minimize the sealing properties of the staple line or a portion thereof.

The arrangement of staple cavities in a staple cartridge corresponds to the arrangement of staples in a staple line generated by the staple cartridge. For example, the spacing and relative orientation of staple cavities in a staple cartridge corresponds to the spacing and relative orientation of staples in a staple line generated by the staple cartridge. In various instances, a staple cartridge can include an arrangement of staples cavities that is selected and/or designed to optimize the flexibility and/or sealing properties of the resultant staple line. A surgeon may select a staple cartridge having a particular arrangement of staple cavities based on the surgical procedure to be performed and/or the properties of the tissue to be treated during the surgical procedure, for example.

In certain instances, it can be desirable to generate a staple line with different staple patterns. A staple line can include a first pattern of staples for a first portion thereof and a second pattern of staples for a second portion thereof. The first pattern and the second pattern can be longitudinally offset. For example, the first pattern can be positioned at the proximal or distal end of the staple line. In other instances, the first pattern and the second pattern can be laterally offset and, in still other instances, the first pattern and the second pattern can be laterally offset and longitudinally offset. A staple line can include at least two different patterns of staples.

In certain instances, the majority of staples in a staple line can form a major pattern and other staples in the staple line can form one or more minor patterns. The major pattern can span a significant portion of the staple line and can include a longitudinally-repetitive sub-pattern. In certain instances, the minor pattern, or irregularity, can deviate from the major pattern. The minor pattern can be an anomaly at one or more locations along the length of the staple line, for example. The different patterns in a staple line can be configured to produce different properties at predefined locations. For example, the major pattern can be a highly flexible or elastic pattern, which can permit extensive stretching of the stapled tissue, and the minor pattern can be less flexible or less elastic. It can be desirable for the majority of the staple line to be highly flexible and for one or more limited portions to be less flexible, for example. In other instances, the minor pattern can be more flexible than the major pattern. In certain instances, because the minor pattern extends along a shorter portion of the staple line, the flexibility of the minor pattern may not impact, or may not significantly impact, the overall flexibility of the entire staple line.

Referring again to <FIG>, the majority of the staple cavities <NUM> in the cartridge <NUM> are arranged in a first pattern, or major pattern, <NUM>. The first pattern <NUM> is a longitudinally-repetitive pattern of angularly-oriented staple cavities <NUM>. Longitudinally-repetitive patterns are patterns in which a sub-pattern or arrangement is longitudinally repeated. For example, an arrangement of three staple cavities on each side of the slot <NUM> (an inner staple cavity, an intermediate staple cavity, and an outer staple cavity) can be repeated along at least a portion of the length of the staple cartridge body <NUM>. The openings <NUM> of the staple cavities <NUM> in the first pattern <NUM> form a herringbone pattern having six rows of angularly-oriented staple cavity openings <NUM> in the cartridge deck surface <NUM>. An inner row 4026a, an intermediate row 4026b, and an outer row 4026c of staple cavities <NUM> are positioned on each side of the slot <NUM>.

Each staple cavity opening <NUM> has a proximal end <NUM> and a distal end <NUM>. The proximal end <NUM> and the distal end <NUM> of the staple cavities <NUM> in the first pattern <NUM> are laterally offset. Stated differently, each staple cavity <NUM> in the first pattern <NUM> is angularly oriented relative to a longitudinal staple cartridge axis SCA. A cavity axis CA extends between the proximal end <NUM> and the distal end <NUM> of each opening <NUM>. The cavity axes CA are obliquely oriented relative to the slot <NUM>. More specifically, the openings <NUM> in the inner rows 4026a of staple cavities <NUM> and the outer rows 4026c of staple cavities <NUM> are oriented at <NUM> degrees, or about <NUM> degrees, relative to the longitudinal staple cartridge axis SCA, and the openings <NUM> in the intermediate rows 4026b of staple cavities <NUM> are oriented at <NUM> degrees, or about <NUM> degrees, relative to the openings <NUM> of the inner rows 4026a and the outer rows 4026c.

In the example of <FIG>, certain staple cavities in the cartridge body <NUM> are oriented at an angle that is anomalous or irregular with respect to the staple cavities <NUM> in the first pattern <NUM>. More specifically, the angular orientation of proximal staple cavities 4022a, 4022b, 4022c, and 4022d and distal staples cavities 4022e, 4022f, <NUM>, and <NUM> does not conform to the herringbone arrangement of the staple cavities <NUM> in the first pattern <NUM>. Rather, the proximal staple cavities 4022a-4022d and the distal staple cavities 4022e-<NUM> are angularly offset from the staple cavities <NUM> in the first pattern <NUM>. The proximal staple cavities 4022a, 4022b, 4022c, and 4022d are obliquely oriented relative to the staples cavities <NUM> in the first pattern <NUM>, and the distal staple cavities 4022e, 4022f, <NUM>, and <NUM> are also obliquely oriented relative to the staples cavities <NUM> in the first pattern <NUM>. The proximal and distal staple cavities 4022a-<NUM> are oriented parallel to the slot <NUM> and to the longitudinal staple cartridge axis SCA.

The proximal staple cavities 4022a-4022d form a proximal pattern <NUM> that is distinct from the first pattern <NUM>, and the distal staple cavities 4022e-<NUM> form a distal pattern <NUM> that is also distinct from the first pattern <NUM>. In the depicted arrangement, the proximal pattern <NUM> includes a first pair of parallel, longitudinally-aligned staple cavities 4022a, 4022b on a first side of the slot <NUM> and a second pair of parallel, longitudinally-aligned staple cavities 4022c, 4022d on a second side of the longitudinal slot <NUM>. The distal pattern <NUM> also includes a first pair of parallel, longitudinally-aligned staple cavities 4022e, 4022f on the first side of the longitudinal slot <NUM> and a second pair of parallel, longitudinally-aligned staple cavities <NUM>, <NUM> on the second side of the longitudinal slot <NUM>. In other instances, the distal pattern <NUM> can be different from the proximal pattern <NUM>.

The proximal pattern <NUM> and the distal pattern <NUM> are symmetric relative to the longitudinal staple cartridge axis SCA. In other instances, the proximal pattern <NUM> and/or the distal pattern <NUM> can be asymmetric relative to the longitudinal staple cartridge axis SCA. For example, the staple cavities 4022e and 4022f can be longitudinally offset from the staple cavities <NUM> and <NUM> and/or the staple cavities 4022a and 4022b can be longitudinally offset from the staple cavities 4022c and 4022d. Additionally or alternatively, in certain instances, the staple cartridge body <NUM> can include either the proximal pattern <NUM> or the distal pattern <NUM>. In other instances, the staple cavities <NUM> defined in the staple cartridge body <NUM> can include additional and/or different patterns of staple cavities <NUM>.

As can be further seen in <FIG>, atraumatic extenders <NUM> extend or protrude from the deck surface <NUM> around a portion of the staple cavities <NUM> in the first pattern <NUM>. The atraumatic extenders <NUM> surround the proximal and distal ends <NUM> and <NUM>, respectively, of the openings <NUM> of the staple cavities <NUM> in the first pattern <NUM>. The atraumatic extenders <NUM> may be configured to grip tissue that is clamped by the end effector. Additionally or alternatively, in certain instances, the tips of the staple legs can protrude from the cartridge body <NUM>. In such instances, the atraumatic extenders <NUM> may be configured to extend flush with and/or beyond the tips of the staple legs to prevent the tips from prematurely penetrating tissue. Consequently, larger staples, e.g., staples having longer legs, can be positioned in the staple cavities <NUM> having atraumatic extenders <NUM> positioned therearound. For example, referring again to <FIG>, larger staples can be positioned in the staple cavities <NUM> in the first pattern <NUM> than the staples in the staple cavities in the proximal pattern <NUM> and the distal pattern <NUM> without risking premature piercing of tissue by the longer staple legs. In certain instances, atraumatic extenders <NUM> can be positioned around staples cavities <NUM> in the proximal pattern <NUM> and/or the distal pattern <NUM>, and larger staples can be positioned in one of more of those staple cavities 4022a-<NUM>, as well.

The staple cartridge body <NUM> can be configured to generate a staple line having different properties along the length thereof. A staple line <NUM> generated by the staple cartridge body <NUM> and embedded in tissue T is depicted in <FIG>. The staple line <NUM> is comprised of staples <NUM>, and an exemplary staple <NUM> for use with various staple cartridges described herein is depicted in <FIG>. The staple <NUM> can be comprised of a bent wire, for example. The wire can have a diameter of <NUM> inches (<NUM>), or approximately <NUM> inches. In other instances, the wire can have a diameter of <NUM> inches (<NUM>), or approximately <NUM> inches. In still other instances, the wire can have a diameter of <NUM> inches (<NUM>), or approximately <NUM> inches. In certain instances, the wire can have a diameter of less than <NUM> inches (<NUM>) or more than <NUM> inches (<NUM>). The reader will appreciate that the diameter of the wire can dictate the diameter of the staple. The staple <NUM> is a substantially U-shaped staple having a base <NUM>, a first leg <NUM> extending from a first end of the base <NUM>, and a second leg <NUM> extending from a second end of the base <NUM>. The first leg <NUM> is substantially parallel to the second leg <NUM> and substantially perpendicular to the base <NUM>. When implanted in tissue T, the angular orientation of the base <NUM> corresponds to the angular orientation of the staple cavity opening <NUM> from which the staple <NUM> was fired.

Another exemplary staple <NUM> that may be used with various staple cartridges described herein is depicted in <FIG>. The staple <NUM> is a substantially "V-shaped" staple having a base <NUM>, a first leg <NUM> extending from a first end of the base <NUM>, and a second leg <NUM> extending from a second end of the base <NUM>. The first leg <NUM> is obliquely oriented relative to the second leg <NUM> and the base <NUM>. When implanted in tissue T, the orientation of the base <NUM> corresponds to the orientation of the staple cavity opening <NUM> from which the staple <NUM> was fired. The reader will appreciate that staples having different geometries can also be fired from the staple cartridges described herein.

Referring again to <FIG>, the staple line <NUM> includes a first portion <NUM>, a proximal portion <NUM>, and a distal portion <NUM>. The first portion <NUM> is generated from the first pattern, or major pattern, <NUM> and extends along a substantial portion of the staple line <NUM>. Owing to the angular orientation of the staples <NUM> in the first portion <NUM>, the first portion <NUM> is substantially flexible or compliant. For example, because the angularly-oriented staples <NUM> can rotate within the stapled tissue T while minimizing trauma to the tissue T, the first portion <NUM> is configured to stretch or extend longitudinally and/or laterally as the stapled tissue stretches.

The proximal portion <NUM> is generated from the proximal pattern <NUM> and forms the proximal end of the staple line <NUM>. The distal portion <NUM> is generated from the distal pattern <NUM> and forms the distal end of the staple line <NUM>. Owing to the parallel orientation of the staples <NUM> in the proximal portion <NUM> and the distal portion <NUM> of the staple line <NUM>, the proximal portion <NUM> and the distal portion <NUM> of the staple line <NUM> can be less flexible than the first portion <NUM>. However, the reduced flexibility of the proximal portion <NUM> and the distal portion <NUM> may not impact, or not substantially impact, the overall flexibility of the staple line <NUM>. Moreover, as described herein, the proximal portion <NUM> and the distal portion <NUM> may not extend adjacent to the cutline and, in certain instances, the proximal portion <NUM> may be absent or missing from the staple line <NUM>.

As described herein, staples are removably positioned in a staple cartridge and fired from the staple cartridge during use. In various instances, the staples can be driven out of staple cavities in the staple cartridge and into forming contact with an anvil. For example, a firing element can translate through the staple cartridge during a firing stroke to drive the staples from the staple cartridge toward an anvil. In certain instances, the staples can be supported by staple drivers and the firing element can lift the staple drivers to eject or remove the staples from the staple cartridge.

An anvil can include a staple-forming undersurface having staple-forming pockets defined therein. In certain instances, the staple-forming pockets can be stamped in the anvil. For example, the staple-forming pockets can be coined in a flat surface of the anvil. The reader will appreciate that certain features of the staple-forming pockets can be a deliberate consequence of a coining process. For example, a certain degree of rounding at corners and/or edges of the staple-forming produce can be an intentional result of the coining process. Such features can also be designed to better form the staples to their formed configurations, including staples that become skewed and/or otherwise misaligned during deployment.

Each staple in the staple cartridge can be aligned with a staple-forming pocket of the anvil. In other words, the arrangement of staple cavities and staples in a staple cartridge for an end effector can correspond or match the arrangement of staple-forming pockets in an anvil of the end effector. More specifically, the angular orientation of each staple cavity can match the angular orientation of the respective staple-forming pocket. For example, when the staple cavities are arranged in a herringbone pattern, the staple-forming pockets can also be arranged in a herringbone pattern.

When staples are driven from the staple cartridge and into forming contact with the anvil, the staples can be formed into a "fired" configuration. In various instances, the fired configuration can be a "B-form" configuration, in which the tips of the staple legs are bent toward the staple base or crown to form a capital letter B having symmetrical upper and lower loops. In other instances, the fired configuration can be a modified B-form, such as a skewed B-form configuration, in which at least a portion of a staple leg torques out of plane with the staple base, or an asymmetrical B-form configuration, in which the upper and lower loops of the capital letter B are asymmetric. Tissue can be captured or clamped within the formed staple.

The arrangement of staples and/or staple cavities in a staple cartridge can be configured to optimize the corresponding arrangement of staple-forming pockets in the forming surface of a complementary anvil. For example, the angular orientation and spacing of staples in a staple cartridge can be designed to optimize the forming surface of an anvil. In certain instances, the footprint of the staple-forming pockets in an anvil can be limited by the geometry of the anvil. In instances in which the staple-forming pockets are obliquely-oriented relative to a longitudinal axis, the width of the anvil can limit the size and spacing of the obliquely-oriented staple-forming pockets. For example, the width of an intermediate row of staple-forming pockets can define a minimum distance between a first row (e.g. an outer row) on one side of the intermediate row and a second row (e.g. an inner row) on the other side of the intermediate row. Moreover, the rows of staple-forming pockets are confined between an inside edge on the anvil, such as a knife slot, and an outside edge of the anvil.

In various instances, the pockets can be adjacently nested along a staple-forming undersurface of the anvil. For example, an intermediate pocket can be nested between an inner pocket and an outer pocket. The angular orientation of the pockets can vary row-to-row to facilitate the nesting thereof. For example, the staple-forming pockets in an inner row can be oriented at a first angle, the staple-forming pockets in an intermediate row can be oriented at a second angle, and the staple-forming pockets in an outer row can be oriented at a third angle. The first angle, the second angle, and the third angle can be different, which can facilitate the close arrangement of the staple-forming pockets.

Referring again to the previous staple cartridge depicted in <FIG> and other previous staple cartridges disclosed in, for example, <CIT>, entitled FASTENER CARTRIDGE FOR CREATING FLEXIBLE STAPLE LINES and/or <CIT>, now <CIT>, entitled METHOD FOR CREATING A FLEXIBLE STAPLE LINE, the varying angles of the staples and the staple cavities in each row can be selected to optimize the nesting of the staple-forming pockets in a complementary anvil. For each such staple cartridge, a complementary anvil can be configured to have a corresponding arrangement of staple-forming pockets. Moreover, the staple-forming pockets in the complementary anvils can be larger than the staple cavities in an effort to facilitate the staple legs land or fall within the staple-forming pockets. For example, the staple legs may be biased outward, such as in the case of V-shaped staples (see <FIG>) and the larger footprint of the staple-forming pockets can catch the outwardly-biased staple legs during firing. In various instances, the staple-forming pockets can be <NUM> inches (<NUM>) to <NUM> inches (<NUM>) longer than the corresponding staple cavities and/or staples. Additionally or alternatively, the staple-receiving cups of each staple-forming pocket can be <NUM> inches (<NUM>) to <NUM> inches (<NUM>) wider than the corresponding staple cavities. In other instances, the difference in length and/or width can be less than <NUM> inches (<NUM>) or more than <NUM> inches (<NUM>).

In instances in which the size of the staples varies within a staple cartridge, the size of the staple-forming pockets can corresponding vary within a complementary anvil. Varying the size of the staple-forming pockets can further facilitate the nesting thereof. For example, in instances in which staple-forming pockets in an intermediate row are shorter than the staple-forming pockets in an inner row or an outer row, the width of the intermediate row of staple-forming pockets can be reduced, which can minimize the requisite spacing between the inner row and the outer row.

The spacing of the staple-forming pockets can also be configured to optimize the nesting thereof. For example, the pockets arranged in an inner row can be longitudinally staggered relative to the pockets arranged in an outer row. Moreover, the pockets in the inner row can partially longitudinally overlap the pockets in the outer row. The pockets in an intermediate row can be longitudinally staggered relative to the pockets in the inner row and the pockets in the outer row. For example, the pockets in the intermediate row can be equidistantly longitudinally offset from the pockets in the outer row and the pockets in the inner row.

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.

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.

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.

Claim 1:
A surgical instrument, comprising:
a surgical staple cartridge comprising a plurality of staple pockets configured to store at least one surgical staple therein;
an anvil (<NUM>) comprising a proximal anvil mounting portion configured to support said anvil (<NUM>) relative to said surgical staple cartridge such that said surgical staple cartridge and said anvil (<NUM>) are movable between an open position, a closed position and an over-closed position;
means for stopping tissue received between said anvil (<NUM>) and said surgical staple cartridge from extending proximally beyond a proximal-most one of said plurality of staple pockets;
a closure member (<NUM>) configured to axially move between a starting position corresponding to said open position of said anvil and said staple cartridge, an intermediate position corresponding to said closed position of said anvil and said staple cartridge and an ending position corresponding to said over-closed position of said anvil and said staple cartridge; and
means (<NUM>, <NUM>, <NUM>, <NUM>) for preventing other tissue from becoming pinched between a distal end of said closure member and said means for stopping when said closure member is in either of said intermediate position and ending position,
wherein said anvil (<NUM>) comprises an elongate anvil body (<NUM>) comprising a staple-forming undersurface and wherein said means for stopping comprises:
a first tissue stop (<NUM>) extending downward below said staple-forming undersurface of said elongate anvil body (<NUM>) on a portion of one side of said elongate anvil body; and
a second tissue stop (<NUM>) extending downward below said staple-forming undersurface of said elongate anvil body (<NUM>) on another portion of another side of said elongate anvil body,
characterized in that each of said first and second tissue stops (<NUM>) comprises an upper proximal end portion (<NUM>) and a bottom proximal end portion (<NUM>) and wherein when said closure member (<NUM>) is in said intermediate position, said upper proximal end portion (<NUM>) of each said first and second tissues stop (<NUM>) is located a first distance (TD<NUM>) from a distal end of said closure member (<NUM>) and said bottom proximal end portion (<NUM>) of each said first and second tissue stops (<NUM>) is located a second distance (TD<NUM>) from said distal end of said closure member (<NUM>) and wherein said second distance differs from said first distance.