Patent Description:
<CIT> discloses a cartridge assembly includes a channel and a removable assembly in releasable engagement with the channel. The removable assembly includes a cartridge body and a support plate. The cartridge body includes an engagement structure disposed adjacent a proximal end thereof. The support plate is configured to mechanically engage the cartridge body and includes an engagement structure disposed adjacent a proximal end thereof. The engagement structure of the cartridge body is configured for longitudinal alignment with the engagement structure of the support plate. The engagement structures of the cartridge body and the engagement structure of the support plate are configured to mechanically engage the engagement structure of the channel when the removable assembly is engaged with the channel.

<CIT> discloses a surgical stapling apparatus (stapler) including a housing, elongated member, and a reload. A cartridge is configured to selectively couple to a first jaw member of the reload and includes one or more resilient members thereon. An anvil operably supported on a second jaw member of the reload is configured to compress one or more fasteners ejected from the cartridge. The anvil includes one or more locking members thereon. A knife is configured to translate through the cartridge and anvil when the first and second jaw members are in a closed
configuration. Engagement between the knife and the resilient member(s) causes the resilient member(s) to move from an initial configuration that allows the knife to travel distally past the locking member(s) to a final configuration that allows the locking member(s) to engage the knife.

Surgical clamping and cutting instruments, such as, for example, surgical stapling instruments, may include an end effector having opposing jaws that clamp tissue and a knife that cuts the clamped tissue. It is often advantageous for an end effector of a surgical stapling instrument to be reusable. To that end, staple cartridges can be fitted into one jaw of the end effector prior to each use of the surgical stapling instrument.

It is desirable to prevent firing of a surgical stapling instrument while a spent cartridge remains in place on the jaw. Thus, a need exists for effective mechanisms to prevent firing of a surgical stapling instrument while a spent staple cartridge is in place in the end effector of the surgical stapling instrument.

The present invention is defined in the independent claims, with optional features being defined in the dependent claims. The following presents a simplified summary of the disclosed subject matter in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview of the disclosed subject matter. It is intended to neither identify key or critical elements of the disclosed subject matter nor delineate the scope of the disclosed subject matter. Its sole purpose is to present some concepts of the disclosed subject matter in a simplified form as a prelude to the more detailed description that is presented later.

The present disclosure relates to surgical stapling instruments having a locking mechanism to prevent actuation of a knife when there is a spent or previously fired cartridge in place.

Also disclosed is, a lockout assembly for use with a surgical stapling instrument including a locking member and a switch. A drive member is configured to releasably engage and translate at least one of a knife or a shuttle in a distal direction through a staple firing stroke. The locking member of the locking assembly is movable from a first position permitting distal translation of the drive member through the staple firing stroke, to a second position inhibiting distal translation of the drive member through the staple firing stroke. A spring may bias the locking member toward the second position. The switch of the locking assembly is movable from a proximal position to a distal position. When the switch is in the proximal position, the switch releasably maintains the locking member in the first position. When the switch is in the distal position, the switch disengages from the locking member thereby allowing the locking member to move to the second position.

Also disclosed is, a surgical stapling instrument including an anvil jaw assembly, and a staple jaw assembly, including a knife and a shuttle. A drive member is configured to releasably engage and translate the knife and shuttle in a distal direction through a staple firing stroke. The knife and shuttle disengage from the drive member upon distal movement of the drive member after the staple firing stroke. The surgical stapling instrument further includes a locking member pivotable from a first position permitting distal translation of the drive member, to a second position preventing distal translation of the drive member. The surgical stapling instrument further includes a switch, that when in a proximal position, releasably maintains the locking member in the first position. When the switch is in a distal position, the switch disengages from the locking member thereby allowing the locking member to move to the second position.

There is also disclosed a surgical stapling instrument including an anvil jaw assembly, and a staple jaw assembly including a shuttle. The surgical stapling instrument further includes a drive member having a knife integrally formed on an edge thereof. The drive member is configured to releasably engage and translate the shuttle in a distal direction through a staple firing stroke. The shuttle disengages from the drive member upon subsequent distal movement of the drive member after the staple firing stroke. The surgical stapling instrument further includes a locking member pivotable from a first position permitting distal translation of the drive member, to a second position preventing distal translation of the drive member. The surgical stapling instrument further includes a switch, that when in a proximal position, releasably maintains the locking member in the first position. When the switch is in a distal position, the switch disengages from the locking member thereby allowing the locking member to move to the second position.

The above and other aspects, features, and advantages of the present surgical stapling instruments having a locking mechanism will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:.

Particular embodiments of the present surgical stapling instruments are described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure and may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.

The present disclosure relates to locking assemblies including a locking member and a switch. A drive member is configured to engage at least one of a knife or a shuttle of a surgical stapling instrument and to translate the knife and/or shuttle in a distal direction through a staple-firing stroke. Contact between the drive member and the knife and/or shuttle is releasable in that once the knife and/or shuttle are translated by the drive member in the distal direction through a staple firing stroke, the knife and/or shuttle disengage from the drive member, remain at a distal portion of the stapling instrument, and are not translated in a proximal direction by the drive member. The locking member is movable from a first position permitting distal translation of the drive member through the staple-firing stroke, and a second position inhibiting distal translation of the drive member through the staple-firing stroke. A spring is configured to bias the locking member toward the second position. The switch of the locking assembly is movable from a proximal position to a distal position. When the switch is in the proximal position, the switch releasably maintains the locking member in the first position. When the switch is in the distal position, the switch disengages from the locking member thereby allowing the locking member to move to the second position.

While the following disclosure is presented with respect to a linear surgical stapler where staples are sequentially fired, it should be understood that the present locking assemblies may be readily adapted for use in any type of surgical clamping and cutting instruments, whether or not the surgical clamping and cutting instrument applies a fastener. The surgical clamping and cutting instrument may be a minimally invasive (e.g., laparoscopic) instrument or an instrument used for open surgery.

Additionally, the present locking assemblies may be readily adapted for use in surgical instruments that are activated using any technique within the purview of those skilled in the art, such as, for example, manually activated surgical instruments, powered surgical instruments (e.g., electro-mechanically powered instruments), robotic surgical instruments, and the like.

<FIG> is a perspective view of an illustrative surgical stapling instrument <NUM> capable of utilizing a locking assembly in accordance with the present disclosure. Surgical stapling instrument <NUM> includes a handle assembly <NUM>, and an end effector <NUM> including an anvil jaw assembly <NUM> and a staple jaw assembly <NUM> mounted on an elongated shaft <NUM> of the surgical stapling instrument <NUM>.

<FIG> shows anvil jaw assembly <NUM>, including an anvil <NUM> having staple forming pockets <NUM> (not shown) supported thereon, and staple jaw assembly <NUM>. Staple jaw assembly <NUM> and anvil jaw assembly <NUM> are configured to move from an open position to a closed position. In the open position, a fresh stapling cartridge can be loaded into jaw assembly <NUM>, a spent staple cartridge removed from jaw assembly <NUM>, and tissue may be positioned between the jaw assemblies <NUM>, <NUM>. In the closed position, jaw assemblies <NUM>, <NUM> cooperate to close upon and clamp tissue such that cartridge <NUM> and anvil <NUM> are in close cooperative alignment. In the embodiment shown in <FIG> and <FIG>, staple jaw assembly <NUM> is stationary and anvil jaw assembly <NUM> pivots to the open position. In other embodiments it is contemplated that the jaw assembly containing the anvil is stationary and the jaw assembly containing the staple cartridge pivots to the open position. As those skilled in the art reading this disclosure will appreciate, in yet other embodiments both the anvil jaw assembly and the staple jaw assembly may pivot.

With continued reference to <FIG>, staple jaw assembly <NUM> includes a staple cartridge <NUM> supported in a channel <NUM> on a lower jaw <NUM>. Cartridge <NUM> includes a plurality of staples <NUM> that are supported on corresponding staple drivers <NUM> provided within respective staple apertures <NUM> formed in cartridge <NUM>. Cartridge <NUM> also includes a shuttle <NUM> having an inclined distal portion <NUM> that, upon distal movement, sequentially acts on staple drivers <NUM>, camming them upwardly thereby moving staples <NUM> into deforming contact with anvil <NUM>. Cartridge <NUM> also includes a knife <NUM> configured to translate distally through a channel <NUM> in cartridge <NUM> and sever clamped, stapled tissue.

<FIG> further shows a drive member <NUM> that is movably supported on the surgical stapling instrument such that it may pass distally through cartridge <NUM> and staple jaw assembly <NUM> when the surgical stapling instrument is fired (e.g., actuated). Also shown in <FIG> is the locking assembly including locking member <NUM> on staple jaw assembly <NUM> and switch <NUM> on cartridge <NUM>.

For a more detailed description of illustrative end effectors, reference may be made to <CIT> and <CIT> It should of course, be understood that end effector shown in <FIG> and <FIG> is merely illustrative, and that other end effectors may be employed, including but not limited to the end effectors shown in <CIT>.

<FIG> shows an illustrative surgical stapling instrument with an unfired reload installed, including drive member <NUM>, spring <NUM>, locking member <NUM>, knife <NUM>, switch <NUM>, and slot <NUM>.

In a fresh reload, drive member <NUM> is in a proximal position where it has not yet engaged knife <NUM>. Drive member <NUM> may be any structure capable of pushing at least one of a shuttle or a knife of a surgical stapling instrument with the necessary force to effectively sever or staple human tissue. Drive member <NUM> may be an I-beam, an E-beam, or any other type of drive member capable of performing similar functions. Drive member <NUM> includes a lower distal portion <NUM> and upper distal portion <NUM>.

When an unfired reload is installed, as in <FIG>, switch <NUM> is in a first proximal position. In a fresh, unfired reload distal portion <NUM> of locking member <NUM> rests on shelf <NUM> of switch <NUM>, keeping engagement portion <NUM> of locking member <NUM> above and out of engagement with slot <NUM>. When locking member <NUM> is in this disabled position, distal translation of drive member <NUM> is permitted, as locking member <NUM> will not obstruct movement of drive member <NUM>.

As seen in <FIG>, an unfired reload containing a new cartridge, knife <NUM> is located on the proximal side of central portion <NUM> of switch <NUM>, which is uncut. Upon installation of an unfired reload, as depicted in <FIG>, retaining snaps <NUM> of switch <NUM> are configured to engage undercuts <NUM> formed on the unfired reload. This interaction, which may be a snap-fit interaction, retains the switch in the proximal position prior to firing of the surgical stapling instrument.

Upon initiation of the staple-firing stroke, as seen in <FIG> drive member <NUM> moves distally to contact knife <NUM>. At this point in the actuation stroke, locking member <NUM> remains out of engagement with slot <NUM> because distal portion <NUM> of the locking member continues to rest on shelf <NUM> of switch <NUM>. In this position, upper distal portion <NUM> of drive member <NUM> contacts knife <NUM> for distal translation as the actuation stroke continues. Lower distal portion <NUM> of drive member <NUM> similarly moves distally in order to engage and translate shuttle <NUM> (see <FIG>).

As illustrated in <FIG>, as drive member <NUM> continues to move distally, knife <NUM> begins to advance. Knife <NUM> is in contact with, and therefore pushes and translates, switch <NUM> from a proximal position, to a distal position. As illustrated in <FIG>, once in the distal position, switch <NUM> separates from and no longer supports distal portion <NUM> of locking member <NUM> which essentially falls off of shelf <NUM>. As a result, engagement portion <NUM> of locking member <NUM> falls into and engages slot <NUM>, enabling the lockout. Spring <NUM> is configured to bias engagement portion <NUM> of locking member <NUM> in the direction of Arrow "B", urging engagement portion <NUM> to drop into slot <NUM> to enable the locking mechanism.

In <FIG>, switch <NUM> is in the distal position. Once switch <NUM> is translated distally, further distal translation is prevented as switch <NUM> becomes obstructed by distal wall <NUM> as best seen in <FIG>. As a result of this obstruction, continued distal translation of knife <NUM> cuts through central portion <NUM> of switch <NUM> (see <FIG>), as a result of the force provided by drive member <NUM> translating knife <NUM> distally. A perspective view of switch <NUM> in the second distal position is shown in <FIG> just before cutting of central portion <NUM>. <FIG> also illustrates stops <NUM>, each including a proximal ramped face <NUM>. As drive member <NUM> translates knife <NUM> distally, and knife <NUM> pushes switch <NUM> distally, switch <NUM> rides over ramped faces <NUM> of stops <NUM>. Distal faces <NUM> of stops <NUM> prohibit movement of switch <NUM> back to its initial proximal position.

In <FIG>, knife <NUM> has cut through central portion <NUM> of switch <NUM> so that knife <NUM> may continue to translate distally towards a final, parked position. As illustrated, stops <NUM> are positioned on the proximal side of switch <NUM>. In this position, retraction of switch <NUM> is impossible, as the proximal portions <NUM> of switch <NUM> abut distal faces <NUM> of stops <NUM>. By preventing switch <NUM> from retracting, it is ensured that locking member <NUM> may not be disengaged, while also keeping both cut parts of switch <NUM> contained in the reload.

Once drive member <NUM> translates distally through a complete firing stroke during which stapling and severing of tissue have occurred, drive member <NUM> can be retracted, leaving knife <NUM> parked at a position in a distal portion of cartridge <NUM>. In embodiments, such as the embodiment illustrated in <FIG> a shuttle <NUM> may be unable to move proximally towards the home position due to friction with cartridge <NUM>. In embodiments, as illustrated in <FIG>, knife <NUM> may be integrally formed with drive member <NUM>. In embodiments, knife <NUM> may be parked in a predetermined position in a distally located garage <NUM>. The garage <NUM> includes lateral surfaces that face the cutting tip of knife <NUM>. As drive member <NUM> is retracted, engagement portion <NUM> of locking member <NUM> is unable to move upwards out of slot <NUM>, as spring <NUM> retains it in the locked position.

Further retraction of drive member <NUM> positions locking member <NUM> distal of the drive member. Because the staple cartridge is spent and there is no proximally positioned switch to hold the locking member out of engagement with slot <NUM>, any attempt to re-fire the surgical stapling instrument will be prevented by drive member <NUM> engaging locking member <NUM>.

In order to disable the lockout of the surgical stapling instrument, an unfired reload (i.e. a new cartridge) must be installed. Each new cartridge contains a new switch <NUM>, shuttle <NUM>, and knife <NUM>. When a new cartridge is installed, switch <NUM> moves proximally causing a distal portion <NUM> of locking member <NUM> to engage with and ride upwards along proximal ramped surface <NUM> of switch <NUM>, until locking member <NUM> is again resting on shelf <NUM>, as may be seen in <FIG>. The lockout is then disabled, allowing for a user to again fire the surgical stapling instrument.

While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of presently disclosed embodiments. Thus the scope of the embodiments should be determined by the appended claims, rather than by the examples given.

Claim 1:
A surgical stapling instrument (<NUM>) comprising:
an anvil jaw assembly (<NUM>);
a staple jaw assembly (<NUM>) including a knife (<NUM>) and a shuttle (<NUM>);
a drive member (<NUM>) configured to releasably engage and translate the knife and the shuttle in a distal direction through a staple firing stroke; and
a locking assembly including:
a locking member (<NUM>) pivotable between a first position permitting distal translation of the drive member, and a second position preventing distal translation of the drive member; and
a switch (<NUM>) movable from a proximal position to a distal position, wherein when the switch is in the proximal position the switch releasably maintains the locking member in the first position, and wherein when the switch is in the distal position the switch disengages from the locking member thereby allowing the locking member to move to the second position,
characterized in that the knife is configured to cut through a center portion of the switch.