Patent Description:
The present application relates generally to surgical occlusion instruments and, more particularly, to surgical staplers.

Surgical staplers are used to approximate or clamp tissue and to staple the clamped tissue together. As such, surgical staplers have mechanisms to ensure that tissue is properly positioned and captured and to drive staples through the tissue. As a result, this has produced, for example, multiple triggers and handles in conjunction with complex mechanisms to provide proper stapling of the clamped tissue. With these complex mechanisms, surgical staplers can have increased manufacturing burdens, as well as potential sources for device failure and confusion for the user. Thus, reliable stapling of clamped tissue without complex mechanisms is desired.

The invention is defined in appended claim <NUM>.

With reference to <FIG>, an embodiment of surgical stapling device is illustrated. The illustrated embodiment of surgical stapler <NUM> comprises an elongate shaft <NUM>, a jaw assembly <NUM>, and a handle assembly <NUM>. <FIG> illustrates the surgical stapler <NUM> with the jaw assembly <NUM> in an open configuration. <FIG> illustrates a removable reload shaft assembly comprising the elongate shaft <NUM> and jaw assembly <NUM> of the surgical stapler <NUM> with the jaw assembly <NUM> in a closed configuration.

With continued reference to <FIG> and <FIG>, the illustrated embodiment of surgical stapler <NUM> can be sized and configured for use in laparoscopic surgical procedures. For example, the elongate shaft <NUM> and jaw assembly <NUM> can be sized and configured to be introduced into a surgical field through an access port or trocar cannula. In some embodiments, the elongate shaft <NUM> and jaw assembly <NUM> can be sized and configured to be inserted through a trocar cannula having a relatively small working channel diameter, such as, for example, less than <NUM>. In other embodiments, elongate shaft <NUM> and jaw assembly <NUM> can be sized and configured to be inserted through a trocar cannula having a larger working channel diameter, such as, for example, <NUM>, <NUM>, <NUM>, or <NUM>. In other embodiments, it is contemplated that certain aspects of the surgical staplers described herein can be incorporated into a surgical stapling device for use in open surgical procedures.

With continued reference to <FIG> and <FIG>, as illustrated, the elongate shaft <NUM> comprises a generally tubular member. The elongate shaft <NUM> extends from a proximal end <NUM> to a distal end <NUM>. The elongate shaft <NUM> defines a central longitudinal axis, L. of the surgical stapler <NUM> extending between the proximal end <NUM> and the distal end <NUM>.

With continued reference to <FIG> and <FIG>, in the illustrated embodiment, the jaw assembly <NUM> is coupled to the elongate shaft <NUM> at the distal end <NUM> of the elongate shaft <NUM>. The jaw assembly <NUM> comprises a first jaw <NUM> and a second jaw <NUM> pivotally coupled to the first jaw <NUM>. In the illustrated embodiment of <FIG> and <FIG>, the jaw assembly <NUM> is articulable with respect to the elongate shaft <NUM> responsive to an articulation mechanism in the handle. <FIG> and <FIG> illustrate a handle assembly that are configured to fire a centrally-fixed jaw assembly to further illustrate an actuation mechanism of the handle assembly in a staple firing sequence. In an initial configuration, the first jaw <NUM> includes a plurality of staples <NUM> disposed therein.

With continued reference to <FIG> and <FIG>, in the illustrated embodiment, the jaw assembly <NUM> can be actuated from an open configuration (<FIG>) to a closed configuration (<FIG>) to a stapling configuration by an actuation member or beam that is longitudinally slideable within the elongate shaft. In an initial position, the beam can be positioned at the distal end <NUM> of the elongate shaft <NUM>. With the beam in the initial position, the second jaw <NUM> is pivoted away from the first jaw <NUM> such that the jaw assembly <NUM> is in the open configuration. The actuation beam engages the second jaw <NUM> upon translation of the actuation member or beam distally along the longitudinal axis L. Translation of the actuation beam distally from the initial position a first distance can actuate the jaw assembly from the open configuration to the closed configuration. With the jaw assembly <NUM> in the closed configuration, the actuation beam can be returned proximally the first distance to return the jaw assembly <NUM> to the open configuration. A distal end of the actuation beam can advance a staple slider configured to deploy staples from the first jaw <NUM> such that further translation of the actuation beam distally past the first distance deploys the plurality of staples <NUM> from the first jaw <NUM>.

With continued reference to <FIG> and <FIG>, in the illustrated embodiment, the handle assembly is coupled to the elongate shaft <NUM> at the proximal end <NUM> of the elongate shaft <NUM>. As illustrated, the handle assembly <NUM> has a pistol grip configuration with a housing defining a stationary handle <NUM> and a movable handle <NUM> or trigger pivotably coupled to the stationary handle <NUM>. It is contemplated that in other embodiments, surgical stapler devices including aspects described herein can have handle assemblies with other configurations such as, for example, scissors-grip configurations, or in-line configurations. As further described in greater detail below, the handle assembly <NUM> houses an actuation mechanism configured to selectively advance an actuation shaft responsive to movement of the movable handle <NUM>.

In some embodiments, the surgical stapler <NUM> can include the plurality of staples <NUM> positioned in a disposable cartridge while the handle assembly <NUM> is configured to be reused with multiple staple cartridges. In the illustrated embodiment, the elongate shaft <NUM> and jaw assembly <NUM> define a disposable cartridge that is removably couplable to the handle assembly <NUM>. Accordingly, in the illustrated embodiment the handle assembly <NUM> includes a coupler <NUM> at the distal end thereof. The coupler <NUM> is adapted to engage the elongate shaft <NUM> of the surgical stapler <NUM> The coupler <NUM> can have a bayonet connection having an outer connector that can removably couple the handle assembly <NUM> to the elongate shaft <NUM>, and an inner connector that can removably couple the actuation shaft of the handle assembly <NUM> to the actuation member of the elongate shaft <NUM>. Accordingly, the surgical stapler <NUM> can be configured such that the handle assembly <NUM> can be reused with multiple disposable cartridges during a surgical procedure. It is contemplated that in other embodiments, the handle assembly and some portion of the elongate shaft can be reusable while a remainder of the elongate shaft and the jaw assembly define a disposable cartridge. In certain other embodiments, the handle assembly and the elongate shaft can be reusable while the jaw assembly defines a disposable cartridge. In still other embodiments, a jaw insert housing a plurality of staples can define a disposable cartridge while the remainder of the surgical stapler is reusable.

<FIG> illustrate various views of an embodiment of handle assembly <NUM> having an articulation mechanism for a surgical stapler <NUM>. The articulation mechanism can be positioned at the proximal end of the handle assembly <NUM> and have an articulation knob <NUM> for articulation of the jaw assembly. In <FIG>, a perspective view of the handle assembly <NUM> as illustrated with the movable handle <NUM> in an open position spaced apart from the stationary handle <NUM>. The illustrated handle assembly <NUM> further comprises a selector <NUM> operably coupled to the actuation mechanism housed within the handle assembly <NUM> as further discussed herein. As illustrated in <FIG>, the selector <NUM> is in a first position.

With reference to <FIG>, another perspective view of the handle assembly <NUM> of <FIG> is illustrated. As illustrated, the movable handle <NUM> is in the open position positioned adjacent the stationary handle <NUM>, and the selector <NUM> is in a second position. <FIG> illustrate a top view of the handle assembly of <FIG> with the selector <NUM>, such as a slider <NUM>, in the first position (<FIG>), and in the second position (<FIG>). <FIG> illustrates a side view of the handle assembly <NUM> of <FIG>, and <FIG> illustrates a cross-sectional side view of the handle assembly <NUM> of <FIG>.

<FIG> illustrate cross-sectional views of the handle assembly <NUM> in an initial configuration, revealing operation of the actuation mechanism <NUM>. In the illustrated embodiment, the actuation mechanism <NUM> is configured to selectively translate the actuation shaft <NUM> from a first position corresponding to the jaw assembly <NUM> being in the open configuration to a second position corresponding to the jaw assembly <NUM> being in the closed configuration and from the second position to a third position to position the jaw assembly <NUM> in a stapling configuration and deploy the plurality of staples <NUM>. In the initial configuration illustrated in <FIG>, actuation mechanism <NUM> can repeatedly translate the actuation shaft <NUM> between the first position and the second position responsive to movement of the movable handle <NUM> or trigger without deploying the staples to provide an open and close functionality. This open and close functionality allows a user to position, clamp tissue, and reposition the stapler <NUM> to find a desirable staple placement location before deploying the staples.

With reference to <FIG>, in the illustrated embodiment, the actuation mechanism comprises an advancing or forward driver <NUM>, a reverse driver <NUM>, an opening driver <NUM>, an advancing surface <NUM>, a reversing surface <NUM>, and an opening surface <NUM>. The forward driver <NUM> can be operably coupled to the movable handle <NUM> such that movement of the movable handle <NUM> from the open position to the closed position advances the forward driver <NUM> in a first direction such as for example distally within the handle assembly <NUM>. The forward driver <NUM> can comprise a pawl or tooth configured to engage a recess or slot.

The reverse driver <NUM> can be operably coupled to movable handle <NUM> such that movement of the movable handle <NUM> from the open position to the closed position advances the reverse driver <NUM> in a second direction opposite the first direction such as, for example proximally within the handle assembly <NUM>. In some embodiments, the movable handle <NUM> can be operably coupled with the reverse driver <NUM> with a geared connection including an idler gear <NUM>. The reverse driver <NUM> can comprise a pawl or tooth configured to engage a recess or slot.

The opening driver <NUM> can be operably coupled to the movable handle <NUM> such that movement of the movable handle <NUM> from the open position to the closed position advances the opening driver <NUM> in a first direction such as for example distally within the handle assembly <NUM>. In the illustrated embodiment, the opening driver <NUM> is coupled to the idler <NUM> with a pin and slot connection to operably couple the opening driver <NUM> to the movable handle <NUM>. The opening driver <NUM> can comprise a pawl or tooth configured to engage a recess or slot.

The actuation shaft <NUM> includes advancing surface <NUM>, reversing surface <NUM>, and opening surface <NUM> formed thereon. In the illustrated embodiment, the advancing surface <NUM> comprises a rack, or plurality of spaced recesses or teeth formed longitudinally along the actuation shaft <NUM>. As illustrated, reversing surface <NUM> comprises a rack or plurality of space recesses or teeth formed longitudinally along the actuation shaft <NUM> and angularly offset from the advancing surface <NUM>. In the illustrated embodiment, the opening surface <NUM> comprises a recess formed in the actuation shaft <NUM>.

In embodiments according to the invention, the actuation shaft <NUM> is rotatable within the handle assembly <NUM> about the longitudinal axis of the stapler <NUM>. The handle assembly <NUM> can comprise a rotation mechanism <NUM> to provide selective rotation of the actuation shaft <NUM> within the handle assembly <NUM>. The actuation shaft <NUM> is rotatable between a first orientation in which the forward driver <NUM> is engageable with the advancing surface <NUM> and a second orientation in which the reverse driver <NUM> is engageable with the reversing surface <NUM>. With the angular offset of the advancing surface <NUM> from the reversing surface <NUM> with respect to the actuation shaft <NUM>, with the actuation shaft in the first orientation, the reverse driver <NUM> is disengaged from the reversing surface <NUM>, and with the actuation shaft in the second orientation, the forward driver <NUM> is disengaged from the advancing surface <NUM>.

With continued reference to <FIG>, in certain embodiments, the rotation mechanism <NUM> comprises a selector <NUM>, such as a slider. The slider can extend transversely through the housing of the handle assembly <NUM>. The slider can be operably coupled to the actuation shaft <NUM> such that positioning the slider in the first position extending from one side of the handle assembly <NUM> positions the actuation shaft <NUM> in the first orientation, and positioning the slider in the second position extending from an opposite side of the handle assembly <NUM> rotates the actuation shaft <NUM> to the second orientation. In the illustrated embodiment, the slider is coupled to a rack <NUM> in meshing engagement with a gear <NUM> that is rotatably fixed to the actuation shaft <NUM> and longitudinally slideable along the actuation shaft <NUM> (such as, for example, with a keyed connection). Desirably, the illustrated rotation mechanism <NUM> including a slider discretely positions the actuation shaft <NUM> in a desired orientation, reducing the incidence of the mismeshed gearing within the actuation mechanism <NUM>. In some embodiments the slider can include visual indicators, such as arrows, to indicate the orientation of the actuation shaft <NUM>, and thus, the actuation mode of the stapler to a user. In other embodiments, the rotation mechanism <NUM>" (<FIG>) can include another mechanism such as a rotatable knob directly rotationally coupled to the actuation shaft, rather than the slider selector <NUM>.

In the illustrated embodiment, the advancing surface <NUM> and the reverse surface <NUM> are angularly offset by approximately <NUM> degrees about the actuation shaft. Thus, the rotation mechanism <NUM> is configured to rotate the actuation shaft approximately <NUM> degrees between the first orientation and the second orientation. In other embodiments, the actuation surface <NUM> and the reverse surface <NUM> can have a different angular offset, such as, for example <NUM> degrees, and the rotation mechanism <NUM> can be configured to rotate the actuation shaft <NUM> correspondingly. Moreover, as described in further detail herein with respect to an open/close mode of the handle assembly <NUM> operation, in the illustrated embodiment, the opening driver <NUM> engages with the actuation shaft in the second orientation, in other embodiments, the actuation shaft can be rotatable to a third orientation in which the opening driver <NUM> engages with the actuation shaft.

With reference to <FIG>, a typical operation sequence of the actuation mechanism <NUM> of the handle assembly <NUM> is illustrated. <FIG> and <FIG> illustrate operation of the handle assembly <NUM> in an initial configuration providing an open/close functionality to the jaw assembly <NUM>. In <FIG>, the movable trigger <NUM> is at an open position, and the actuation shaft <NUM> is at a first position, corresponding to the first position of the actuation beam at the distal end of the elongate shaft <NUM>. In the initial position, the actuation shaft <NUM> is positioned at the second orientation such that the reverse driver <NUM> is angularly aligned with the reversing surface <NUM>. With actuation shaft <NUM> in the second orientation, the opening driver <NUM> is positioned within the opening surface <NUM> or recess. Movement of the movable handle <NUM> from the open position (<FIG>) to the closed position (<FIG>), advances the forward driver <NUM> distally along the actuation shaft <NUM> to engage an advancing recess <NUM> formed in the actuation shaft <NUM> and drive the actuation shaft <NUM> distally in the handle assembly <NUM> to a second position. The second position of the actuation shaft <NUM> within the handle assembly <NUM> corresponds to the second position of the actuation beam, which positions the jaw assembly <NUM> in a closed configuration.

The movable handle <NUM> can be biased to the open position by a biasing member, such as a coil spring <NUM> (<FIG>). Thus, releasing the movable handle <NUM> from the closed position illustrated in <FIG> would return it to the open position of <FIG>. Operable coupling of the movable handle <NUM> to the opening driver <NUM> would likewise translate the opening driver <NUM> proximally within the handle assembly <NUM> as the movable handle <NUM> returns to the open position. In the second orientation of the actuation shaft <NUM>, the opening driver <NUM> engages opening surface <NUM> such that the proximal movement of the opening driver <NUM> returns the actuation shaft <NUM> from the second position to the first position, returning the jaw assembly <NUM> to the open configuration.

A user can seek a desired stapling position within a surgical field by repeatedly opening and closing the jaws to clamp tissue in various locations. Once a desired stapling position has been selected, the actuation mechanism <NUM> can be configured in a stapling or firing mode by rotating the actuation shaft <NUM> to the first orientation. With the jaw assembly a closed configuration at a desired stapling position (as illustrated in <FIG>), a user can reposition the selector <NUM> by sliding the slider to the first position, corresponding to the first orientation of the actuation shaft <NUM> (as illustrated in <FIG>). In the first orientation of the actuation shaft <NUM>, the forward driver <NUM> is engageable with the advancing surface <NUM>, the reversing driver <NUM> is angularly misaligned with the reversing surface <NUM>, and the opening driver <NUM> angularly misaligned with the opening surface <NUM>. With the actuation shaft <NUM> in the first orientation, the movable handle <NUM> can be released into the open position (<FIG>), engaging the forward driver <NUM> with the advancing surface <NUM>.

With reference to <FIG> and <FIG>, with the actuation shaft <NUM> in the first orientation, and the forward driver <NUM> engaging the advancing surface <NUM>, the actuation mechanism <NUM> is in a stapling or firing mode. Several cycles of movable handle <NUM> movement from the open position to the closed position and back to the open position advance the actuation shaft <NUM> from the second position (<FIG>), to a third position in which the actuation shaft <NUM> is moved to its distal-most limit with respect to the handle assembly <NUM> (<FIG>). In some embodiments, the actuation mechanism can include a stop to interfere with distal travel of the actuation shaft <NUM> at the third position. The second position of the actuation shaft corresponds to the second position of the actuation beam in the jaw assembly <NUM>. The third position of the actuation shaft corresponds to the third position of the actuation beam in the jaw assembly <NUM> in which the plurality of staples have been deployed from the first jaw. With movement of the movable handle <NUM> or trigger in the firing mode to advance the actuation shaft from the second position to the third position, the forward driver <NUM> is sequentially advanced over the adjacent teeth or grooves of the actuating surface <NUM> in a ratchet-like advancement.

With reference to <FIG>, once the actuation shaft <NUM> has been advanced to the third position and the staples have been fired from the jaw assembly, the actuation mechanism <NUM> can be configured in a reverse mode. Accordingly, the rotation mechanism <NUM> can rotate the actuation shaft <NUM> to the second orientation to position the reversing surface <NUM> in angular alignment with the reverse driver <NUM>. The slider can be slid to the second position to rotate the actuation shaft from the first orientation (<FIG>) to the second orientation (<FIG>). With the actuation shaft <NUM> in the second orientation, repeated cycles of the movable handle <NUM> from the open position to the closed position and back to the open position engage the reverse driver <NUM> with the reversing surface <NUM> in a ratchet-like advancement while retracting the actuation shaft <NUM> proximally in the handle assembly <NUM>. Once the reverse driver <NUM> has driven the actuation shaft <NUM> proximally to the second position (illustrated in <FIG>), the opening driver <NUM> engages the opening surface <NUM>. The opening driver <NUM> returns the actuation shaft <NUM> to the first position when the movable handle <NUM> is released to the open position. (Returning the handle assembly to the configuration illustrated in <FIG>). With the actuation shaft <NUM> in the first position, the cartridge, emptied of staples, can be decoupled from the handle assembly <NUM> and a new cartridge can be coupled to the handle assembly to begin another stapling operation.

With reference to <FIG>, and <FIG>, an embodiment of articulation mechanism for the handle assembly <NUM> is illustrated. In the illustrated embodiment, the handle can articulate the jaw assembly at the distal end of the shaft up to <NUM>° in a fully articulated position in either direction relative to a longitudinally centered position. In some embodiments, the handle assembly uses a manual articulation mechanism including a series of components coupled to the manually actuated articulation knob <NUM> at the proximal end of the handle. It is contemplated that in other embodiments, the articulation knob and certain components of the articulation mechanism can be disposed at other locations on the handle assembly such as, for example, the distal end, an upper surface thereof, or on the stationary handle.

With reference to <FIG>, the articulation mechanism is coupled to an articulation member <NUM> extending longitudinally within the reload shaft when the reload shaft is coupled to the handle. Actuation of the articulation mechanism longitudinally translates the articulation member <NUM> proximally or distally relative to the shaft to articulate the jaw assembly at the distal end of the shaft.

With reference to <FIG>, the articulation mechanism comprises a ball screw <NUM> having at least one helical groove or thread <NUM> in which one or more ball bearing <NUM> can ride. In the illustrated embodiment, the articulation mechanism comprises two ball bearings <NUM> that are engageable in two threads <NUM>. The ball bearings <NUM> are positioned in ball bearing apertures <NUM> in a ball sleeve <NUM> positioned radially outwardly of the ball screw <NUM>. The ball bearings <NUM> are maintained in the threads <NUM> by a release sleeve <NUM> positioned radially outward of the ball bearings <NUM>. Rotation of the articulation knob <NUM>, which is coupled to the ball sleeve <NUM> such as by connecting pins <NUM>, rotates the ball sleeve <NUM> about an axis of rotation, causing the ball bearings <NUM> to travel within the threads <NUM> and correspondingly longitudinally translate the ball screw <NUM>. Articulation of the jaw assembly is accomplished by rotating the articulation knob <NUM> to correspondingly rotate the ball sleeve <NUM> and the ball bearings <NUM> about the axis of rotation while their longitudinal position is fixed along the axis of rotation. The ball bearings <NUM>, which are engaged in the threads <NUM> of the ball screw <NUM> will then translate the ball screw <NUM> forward and reverse along the axis of rotation. In the illustrated embodiment, the ball sleeve <NUM> is generally tubular, having a cavity formed therein, and a portion of the ball screw <NUM> is positioned within the cavity and translates longitudinally within the cavity. While the illustrated embodiment of articulation mechanism includes two ball bearings engageable threads in a ball screw, it is contemplated that in other embodiments, the articulation mechanism can have fewer or more than two ball bearings such as, for example, a single ball bearing positioned in a single helical screw or three or more ball bearings in a corresponding number of helical threads.

With reference to <FIG>, the ball screw <NUM> extends to a distal end <NUM> coupled to a pair of articulation links <NUM>. The articulation links <NUM> are spaced apart from one another, which desirably allows them to be positioned radially outwardly of the actuation mechanism and actuation shaft within the handle. As illustrated in <FIG>, the articulation links <NUM> can comprise a mating feature such as a slot formed therein to allow them to be keyed into a corresponding mating feature such as a post extending radially inwardly from the handle body. The slots can stabilize the articulation links relative to the handle and interaction of the handle posts with ends of the slots can define a range of articulation for the articulation mechanism. The distal ends of the articulation links <NUM> can be rotatably coupled to the articulation adapter <NUM>, which can be positioned coaxially radially outwardly of the actuation adapter at the distal end of the handle. This rotational coupling can include an articulation bearing <NUM> having relatively low friction properties. This articulation bearing <NUM> can facilitate rotation of a coupled reload shaft relative to the handle assembly and longitudinal movement of the articulation adapter <NUM> during operation of the articulation mechanism. While the illustrated embodiment of articulation mechanism includes two articulation links laterally offset from the actuation mechanism within the handle, it is contemplated that in other embodiments, the articulation mechanism can have fewer or more than two articulation links such as, for example, an articulation link or three or more articulation links.

With continued reference to <FIG>, the articulation adapter <NUM> can be connected to the articulation member <NUM> in the shaft by a bayonet connection when the shaft is coupled to the handle. The articulation member <NUM> extends distally within the shaft and is coupled to an end effector or jaw assembly articulably coupled to the shaft. The threads <NUM> can be configured such that moving the ball screw proximally will articulate the jaw assembly to the left when viewed from the handle relative to a longitudinally centered position and moving the ball screw <NUM> distally will articulate the jaw assembly to the right when viewed from the handle relative to the centered position.

Advantageously, since the helical threads <NUM> of the ball screw <NUM> are continuous, the articulation mechanism can allow the jaw assembly to be articulated to virtually infinite angular positions between a desired operational range. In some embodiments, the articulation mechanism can be configured to provide an articulation operational range from -<NUM>° to +<NUM>° of the jaw assembly relative to a longitudinally centered position defined by the longitudinal axis of the shaft. In other embodiments, the articulation mechanism can be configured to provide other operative articulation ranges including ranges providing more than +/-<NUM>° of articulation or those providing less than +/-<NUM>° of articulation. In some embodiments, the articulation mechanism can be configured to provide articulation in a single direction relative to a longitudinally centered position.

In some embodiments, the pitch of the threads <NUM> on the ball screw <NUM> is variable. For example, the threads <NUM> can include a relatively low pitch towards an end of the threads to advantageously provide a larger mechanical advantage when the jaw assembly can require more force to articulate. The threads <NUM> can include a relatively higher pitch towards a center of the threads to allow rapid movement with a relatively lower mechanical advantage where the jaw assembly can require a lower force to articulate. In other embodiments, the threads <NUM> include a constant pitch such that rotation of the articulation knob results in a proportional amount of articulation of a jaw assembly of the stapler that does not vary over the articulation range of the articulation mechanism. Desirably, such a constant pitch thread ball screw can result in an easily predictable response during operation of the actuation mechanism.

With reference to <FIG>, the articulation mechanism can comprise a release mechanism that allows the articulation mechanism to advantageously be reset to the longitudinally centered position from any articulated position. The release mechanism is operated by user pressing a release button <NUM>. In the illustrated embodiment, the release button <NUM> is positioned radially nested within the articulation knob <NUM>.

With reference to <FIG>, operation of the release button <NUM> will distally advance the release sleeve <NUM>. A radially inner surface of the release sleeve <NUM> is stepped to include an engagement surface <NUM> having a relatively small inner diameter and a release surface <NUM> having a relatively larger inner diameter with a smooth ramp between the engagement surface and the release surface. In operation, the engagement surface of the release sleeve maintains the ball bearings <NUM> in the threads <NUM> of the ball screw <NUM>. Once the release button <NUM> is pushed, the engagement surface is distally advanced, allowing the ball bearings <NUM> to disengage from the threads <NUM> and advance radially outward through the ball bearing apertures <NUM> in the ball sleeve <NUM> (<FIG>) against the release surface.

With reference to <FIG>, with the ball bearings <NUM> disengaged from the threads <NUM>, the articulation mechanism can be biased to a centered position. In some embodiments, the ball screw <NUM> is biased to a centered position by a biasing member such as two springs <NUM> and spring force from the shaft. The ball bearings <NUM> positioned in the centered position (<FIG>) along the threads <NUM> corresponds to a longitudinally centered position of the jaw assembly.

With reference to <FIG>, once the release button <NUM> is allowed to return to an undisturbed configuration, release sleeve <NUM> is retracted proximally (indicated by arrows <NUM>) by a spring. Proximal movement of the release spring <NUM> forces the ball bearings <NUM> into engagement with the threads <NUM> of the ball screw. Thus, the articulation mechanism can then be used to articulate the jaw assembly from the longitudinally centered position, or the stapler can be used with the jaw assembly in the longitudinally centered position.

In certain embodiments, the handle assemblies described herein can further comprise an articulation lockout mechanims. Embodiments according to the invention comprise a shaft coupling firing lockout mechanism. The articulation lockout mechanism can be configured to prevent operation of the articulation mechanism with no reload shaft coupled to the handle assembly and allow operation of the articulation mechanism as described above with respect to <FIG> when a reload shaft is coupled to the handle assembly. Desirably, this articulation lockout mechanism facilitates coupling the articulation mechanism as described with respect to <FIG> as the reload shaft is coupled to the handle assembly. If the articulation mechanism were maintained in an engaged configuration even when no instrument shaft were coupled to the handle assembly, it could be difficult to align the articulation member within the instrument shaft with the articulation adapter <NUM> in an attempt to couple the instrument shaft with the handle assembly.

The shaft coupling firing lockout mechanism is configured to prevent a user from selecting a firing mode of the handle assembly unless a reload shaft is coupled to the handle assembly. Thus, desirably, a user is prevented from initiating a firing operation if the reload shaft is not secured to the handle assembly. In the illustrated embodiment, the articulation lockout mechanism and shaft firing lockout mechanism are integrated and share certain components. This integrated mechanism can desirably present manufacturing and packaging efficiencies. It is contemplated that in other embodiments a handle assembly can include an articulation lockout mechanism that is distinct from a shaft coupling firing lockout mechanism.

With reference to <FIG>, a perspective view of an embodiment of handle assembly having an articulation lockout mechanism and a shaft coupling firing lockout mechanism are illustrated with a portion of a housing of the handle assembly removed to illustrate the mechanisms therein. As illustrated in <FIG>, the articulation lockout mechanism and shaft coupling firing lockout mechanism are in a locked out configuration corresponding to no reload shaft coupled to the handle assembly. As illustrated in <FIG>, the articulation lockout mechanism and shaft coupling firing lockout mechanism are in an unlocked configuration corresponding to a reload shaft coupled to the handle assembly.

With continued reference to <FIG>, the articulation lockout mechanism comprises a lockout sleeve <NUM> at the distal end of the handle assembly and at least one lockout arm <NUM> coupled to the lockout sleeve. In the illustrated embodiment, the lockout sleeve <NUM> can be positioned radially outwardly of the articulation adapter <NUM>. In the illustrated embodiment, the articulation lockout mechanism comprises two lockout arms <NUM> extending longitudinally within the handle assembly from a proximal end coupled to a locking sleeve <NUM> positioned around the release sleeve <NUM> of the articulation mechanism to a distal end coupled to the lockout sleeve <NUM>. The lockout arms <NUM> can extend parallel to and offset from the articulation links <NUM> of the articulation mechanism. The lockout arms can be positioned laterally outwardly of the actuation shaft <NUM> and other actuation mechanism components. In other embodiments, one or more than two lockout arms <NUM> can couple the lockout sleeve <NUM> to the release sleeve <NUM>, and the lockout arms <NUM> can be disposed in a different lateral position than in the illustrated embodiment.

With continued reference to <FIG>, in the illustrated embodiment, the shaft coupling firing mechanism comprises the lockout sleeve <NUM> at the distal end of the handle assembly and the at least one lockout arm <NUM> coupled to the lockout sleeve <NUM> and extending proximally therefrom. The at least one lockout arm <NUM> comprises at least one lockout tab <NUM> extending radially inwardly therefrom. In the illustrated embodiment, the articulation lockout mechanism comprises two lockout arms <NUM>, on laterally opposed sides of the actuation shaft <NUM>, and one of the two lockout arms <NUM> comprises one lockout tab <NUM>. As further discussed with reference to <FIG> and <FIG>, in certain embodiments to provide lock out functionality during engagement of an instrument shaft with the handle assembly, a lockout arm <NUM> can comprise two lockout tabs: a proximal lockout tab <NUM> and a distal lockout tab <NUM> with a lockout recess <NUM> therebetween.

With reference to <FIG>, perspective views of the shaft coupling firing lockout mechanism are illustrated. As illustrated in <FIG>, the shaft coupling firing lockout mechanism is in a locked out configuration corresponding to no reload shaft being coupled to the handle assembly. As illustrated in <FIG>, the shaft coupling firing lockout mechanism is in an unlocked configuration corresponding to a reload shaft being coupled to the handle assembly.

With reference to <FIG>, the shaft coupling firing lockout mechanism is biased longitudinally distally. For example, in some embodiments a coil spring can bias the lockout sleeve <NUM> distally relative to the handle assembly. With no reload shaft coupled to the handle assembly, the lockout sleeve <NUM> and lockout arm <NUM> are biased to a distal position corresponding to the locked out configuration of the shaft coupling firing lockout configuration. With the lockout arm <NUM> in the distal position, the lockout tab <NUM> is longitudinally aligned with the gear <NUM> of the rotation mechanism. In this position, the lockout tab <NUM> prevents rotation of the gear <NUM> such that a user is unable to rotate the actuation shaft <NUM> to a firing orientation. In certain embodiments, the gear <NUM> can comprise a slot <NUM> positioned to receive the lockout tab of the lockout arm <NUM>.

With reference to <FIG>, as a reload shaft is coupled to the handle assembly, a lockout keyway <NUM> (<FIG>) engages the lockout sleeve <NUM> and advances the lockout sleeve <NUM> and lockout arm <NUM> longitudinally proximally a predetermined distance to a proximal position. In the proximal position, as illustrated, the lockout tab <NUM> is misaligned with the gear <NUM> of the rotation mechanism such that the rotation mechanism can be actuated by the selector <NUM> as described with respect to <FIG>.

Thus, desirably, the shaft coupling firing lockout mechanism prevents initiating a firing actuation of the handle assembly without a reload shaft fully coupled to the handle assembly. Desirably, this lockout mechanism can facilitate proper alignment of the bayonet coupling features of the handle assembly and reload shaft during an initial coupling of the reload shaft to the handle assembly. Furthermore, the lockout mechanism can desirably prevent an inadvertent attempt to fire a reload shaft that is not securely, fully coupled to the handle assembly.

With reference to <FIG>, cut away top views of the articulation lockout mechanism are illustrated. As illustrated in <FIG>, the articulation lockout mechanism is in a locked out configuration corresponding to no reload shaft being coupled to the handle assembly. As illustrated in <FIG>, the articulation lockout is in an unlocked configuration corresponding to a reload shaft being coupled to the handle assembly.

With reference to <FIG>, with no reload shaft coupled to the handle assembly, the lockout sleeve at the distal end of the handle assembly is biased to the distal position, advancing the lockout arms <NUM> and locking sleeve <NUM> to a distal position. As illustrated, the locking sleeve <NUM> is positioned around the release sleeve of the articulation mechanism. In embodiments of handle assembly having an articulation lockout, the release sleeve <NUM> can comprise a flange <NUM> protruding radially outwardly at a distal end of the release sleeve. As the locking sleeve <NUM> is biased to the distal position corresponding to a locked out configuration of the articulation lockout mechanism, the locking sleeve <NUM> engages the flange <NUM> of the release sleeve <NUM>, moving the release sleeve distally to release ball bearings <NUM> from the ball screw as described above with reference to <FIG>. Accordingly, with no reload shaft coupled to the handle assembly, the articulation knob may be rotated without actuating the articulation mechanism because the ball bearings <NUM> are disengaged from the threads of the ball screw.

Thus, in certain embodiments, the articulation lockout mechanism can maintain the articulation mechanism in a centered position if no instrument shaft is coupled to the handle assembly. This centered position of the articulation adapter can facilitate the bayonet coupling of instrument shaft and handle assembly previously discussed above. If the articulation mechanism were maintained in an engaged configuration even when no instrument shaft were coupled to the handle assembly, it could be difficult to align the articulation member within the instrument shaft with the articulation adapter <NUM> in an attempt to couple the instrument shaft with the handle assembly.

With reference to <FIG>, once a reload shaft has been coupled to the handle assembly, the lockout sleeve at the distal end of the handle assembly is advanced to the proximal position, advancing the lockout arms <NUM> and locking sleeve <NUM> to a proximal position. As illustrated, with the locking sleeve <NUM> in the proximal position, the locking sleeve <NUM> is spaced apart from the flange <NUM> of the release sleeve. <NUM> Accordingly, with the articulation lockout mechanism in the unlocked configuration, ball bearings <NUM> are engaged with the ball screw, as described above with respect to <FIG>, and the articulation mechanism and its release button are operable as described above with respect to <FIG>. Thus, with an instrument shaft attached, rotation of the articulation knob results in translation of the articulation adapter to articulate an end effector coupled to the instrument shaft.

While in certain embodiments, the shaft coupling firing lockout mechanism can have a locked out configuration in which the lockout sleeve is biased to the distal position and an unlocked configuration in which a shaft has been coupled to the handle assembly, as discussed above with respect to <FIG>, in certain embodiments, the reload shaft and shaft coupling firing lockout mechanism can be configured to further comprise an engagement position of the lockout mechanism in which the reload shaft is being coupled to the handle assembly but not yet fully seated. It can be desirable that the reload shaft is securely coupled to the handle assembly before a firing operation is initiated to facilitate the reliable firing of staples. Thus, in certain embodiments, the shaft coupling firing lockout mechanism can be configured to position the lockout sleeve and lockout arm in a locked out configuration while the reload shaft is being coupled to the handle assembly. In certain embodiments, a lockout keyway on the reload shaft can be sized and configured to engage the lockout sleeve of the handle assembly to initially position the lockout sleeve and the shaft coupling firing lockout mechanism in the engagement position during coupling of the shaft with the handle assembly, then position the lockout sleeve and the shaft coupling firing lockout mechanism in the proximal position once the reload shaft is securely coupled to the handle assembly.

With reference to <FIG>, an embodiment of reload shaft for use with a handle assembly having a shaft coupling firing lockout mechanism and an articulation lockout mechanism is illustrated. <FIG> illustrates a side view of the reload shaft <NUM> having a proximal end <NUM> configured to couple to the coupler <NUM> of the handle assembly. <FIG> is a detail perspective view of the proximal end <NUM> of the reload shaft <NUM> having a lockout keyway <NUM> therein. The lockout keyway <NUM> comprises at least one notch <NUM> formed therein that is engageable with the lockout sleeve to sequentially position the shaft coupling firing lockout mechanism initially in the engagement position corresponding to a locked out configuration of the mechanism, then to the proximal position, corresponding to an unlocked configuration of the mechanism.

With reference to <FIG>, an exemplary embodiment of lockout keyway <NUM> is illustrated. The illustrated lockout keyway 310has a height H to a proximal edge, a notch <NUM> recessed from the height H. The lockout keyway comprises a ramped edge <NUM> extending between the proximal edge and at least one side of the notch <NUM>. Each of the lockout keyways further comprise a key, such as a rib <NUM> to restrict rotation of the lockout keyway relative to the reload shaft as the reload shaft is coupled with the handle assembly.

With reference to <FIG>, an exemplary lockout sleeve <NUM> of the handle assembly is illustrated. In the illustrated embodiment, the lockout sleeve <NUM> comprises an engagement feature such as a flange <NUM> at a proximal end and at least one rib <NUM> or other key element protruding from the outer surface thereof to maintain an orientation of the lockout sleeve <NUM> relative to a longitudinal axis of the actuation shaft. As illustrated, the lockout sleeve <NUM> further comprises at least one mating protrusion such as a tooth <NUM> extending distally from the distal end thereof positioned to engage a corresponding notch of a lockout keyway of a connected reload shaft. The at least one tooth <NUM> can have a ramped edge <NUM> such that it can matingly engage a notch of a lockout keyway that likewise has a ramped edge. In the illustrated embodiment, the lockout sleeve <NUM> comprises two teeth <NUM> positioned diametrically opposed on a distal end of the lockout sleeve <NUM> to engage a corresponding two identification notches. In other embodiments, it is contemplated that the number and locations of mating features included the lockout keyways and lockout sleeves can be varied.

With reference to <FIG>, an exemplary sequence of interaction between a lockout sleeve <NUM> and a lockout keyway <NUM> is illustrated as a reload shaft is installed on a handle assembly. As illustrated, the shaft installation sequence proceeds from left to right. In the left panel, as the shaft is positioned in the coupler <NUM> (<FIG>) of the handle assembly, the lockout sleeve <NUM> is oriented such that the teeth <NUM> are misaligned with the notches <NUM>. The coupler <NUM> and shaft engage in a bayonet connection in which the shaft is advanced longitudinally proximally relative to the handle, then rotated relative to the longitudinal axis. The center panel illustrates the proximal longitudinal movement longitudinally proximally displacing the lockout sleeve <NUM> relative to the handle as the rotational movement of the shaft moves the teeth <NUM> closer to alignment with the notches <NUM>. The right panel illustrates completion of rotation of the shaft relative to the handle assembly to secure the bayonet coupling. As illustrated, once the shaft is coupled to the handle assembly, the teeth <NUM> of the lockout sleeve <NUM> engage and are positioned within the notches <NUM> of the lockout keyway <NUM>. Thus, during a coupling operation, the lockout sleeve <NUM> is initially displaced proximally by installation of the shaft with the teeth misaligned with the notches, then returns distally as the teeth <NUM> engage the notches <NUM>. Thus, in the illustrated embodiment as a bayonet coupling is initiated, the lockout sleeve is advanced longitudinally proximally to the engagement position of the shaft coupling firing lockout mechanism. Once the reload shaft has been rotated with respect to the handle assembly to complete the bayonet coupling, the lockout sleeve is biased distally to the proximal position corresponding to an unlocked configuration of the shaft coupling firing lockout mechanism.

With reference to <FIG>, a side view of the shaft coupling firing lockout mechanism is illustrated in the engagement position. In the illustrated embodiment, the lockout arm <NUM> comprises two lockout tabs <NUM>, <NUM> separated by a lockout recess <NUM> to provide a locked out configuration with the lockout arm <NUM> in the engagement position. Initially with no reload shaft coupled to the handle assembly, the shaft coupling firing lockout mechanism is positioned in a locked out configuration similar to <FIG>. In this locked out configuration, the lockout sleeve <NUM> and lockout arm <NUM> are biased to a distal position such that the proximal lockout tab <NUM> is positioned to prevent rotation of the gear <NUM> of the rotation mechanism. As the reload shaft is advanced proximally in a bayonet coupling operation with the handle assembly, the lockout sleeve <NUM> and lockout arm <NUM> are advanced proximally to the engagement position of the shaft coupling firing lockout mechanism in which the distal lockout tab <NUM> is positioned to prevent rotation of the gear <NUM> of the rotation mechanism.

With reference to <FIG>, a side view of the shaft coupling firing lockout mechanism of <FIG> is illustrated in the proximal position corresponding to an unlocked configuration of the lockout mechanism. Once the reload shaft is rotated to securely couple the reload shaft to the handle assembly, the lockout sleeve <NUM> and lockout arm <NUM> are biased distally to the proximal position of the shaft coupling firing lockout mechanism in which the lockout recess <NUM> is positioned to allow rotation of the gear <NUM> of the rotation mechanism. Thus, with the lockout arm <NUM> in the proximal position as illustrated, the shaft coupling firing lockout mechanism is in the unlocked configuration.

Claim 1:
A handle assembly (<NUM>) for a surgical stapler, the handle assembly comprising:
a handle body comprising a stationary handle (<NUM>) and a movable handle (<NUM>) pivotably coupled to the handle body, the handle body comprising a coupler (<NUM>) configured to removably couple to an instrument shaft (<NUM>) having a stapler jaw assembly (<NUM>);
an actuation shaft (<NUM>) mechanically coupled to the movable handle (<NUM>) for manual actuation thereof, the actuation shaft (<NUM>) slidable within the handle body along a longitudinal axis, the actuation shaft (<NUM>) selectively positionable in a first orientation wherein movement of the movable handle (<NUM>) relative to the stationary handle (<NUM>) distally advances the actuation shaft (<NUM>) and a second orientation wherein movement of the movable handle (<NUM>) relative to the stationary handle (<NUM>) proximally retracts the actuation shaft (<NUM>); and
a shaft coupling firing lockout mechanism, the shaft coupling firing lockout mechanism preventing selective positioning of the actuation shaft (<NUM>) in the first orientation when no instrument shaft (<NUM>) is coupled to the coupler (<NUM>) and allowing selective positioning of the actuation shaft (<NUM>) in the first orientation when the instrument shaft (<NUM>) is coupled to the coupler (<NUM>).