Patent Description:
Surgical stapling devices for simultaneously stapling and cutting tissue are well known in the art. Typically, these stapling devices include a tool assembly and a drive assembly. The tool assembly includes an anvil assembly and a cartridge assembly. The cartridge assembly includes a channel member and a staple cartridge that includes a cartridge body, a knife, and an actuation sled. The drive assembly is movable in relation to the anvil and cartridge assemblies to advance the actuation sled and knife through the staple cartridge to move the tool assembly between open and clamped positions, to eject staples from the staple cartridge, and cut tissue clamped between the anvil and cartridge assemblies. After the stapling device is fired, the actuation sled remains in an advanced position within the tool assembly.

In some stapling devices, the staple cartridge is removably received within the channel member of the cartridge assembly and is replaceable to facilitate reuse of the stapling device. In order to prevent actuation of the tool assembly after the staples have been fired from the staple cartridge, the tool assembly may include a lock mechanism that is movable from an unlocked position to a locked position into engagement with the drive assembly when the sled is in its advanced position to prevent readvancement of the drive assembly. In some stapling devices, the lock mechanism is movable to the unlocked position in response to insertion of a new or unfired staple cartridge into the channel member.

A continuing need exists for a lock mechanism of simple construction that can prevent advancement of a drive assembly of a stapling device when a spent staple cartridge is positioned within the channel member of the cartridge assembly.

Further embodiments are provided by the dependent claims.

This disclosure is directed to a surgical stapling device having a tool assembly that includes an anvil and a cartridge assembly that are movable in relation to each other between open and clamped positions. The anvil supports a lock mechanism that includes a lock member that moves from a locked position to an unlocked position in response to movement of the tool assembly from the open position to the clamped position.

One aspect of the disclosure is directed to a surgical stapling device including an elongate body, a tool assembly, a lock mechanism, and a drive assembly. The elongate body has a proximal portion and a distal portion. The tool assembly is supported on the distal portion of the elongate body and includes a cartridge assembly and an anvil. The cartridge assembly includes a channel member and a staple cartridge. The staple cartridge is removably received within the channel member and includes a cartridge body, staples, and an actuation sled assembly including an actuation sled. The actuation sled assembly is movable through the cartridge body between retracted and advanced positions. The anvil includes a body that is coupled to the cartridge assembly such that the tool assembly is movable between open and clamped positions. The lock mechanism is supported on the anvil and includes a lock member that is rotatable between a locked position and an unlocked position in response to movement of the tool assembly from the open position to the clamped position. The drive assembly includes a clamp member that is movable in relation to the tool assembly between retracted and advanced positions. The lock member is positioned to prevent movement of the clamp member from the retracted position to the advanced position in the locked position.

The lock member is biased towards the locked position.

The lock mechanism includes a biasing member to urge the lock member towards the locked position.

The biasing member includes a coil spring.

The actuation sled assembly includes a knife that is supported on the actuation sled.

The lock member engages the actuation sled assembly when the actuation sled assembly is in its retracted position to retain the lock member in the unlocked position.

The lock member engages the knife of the actuation sled assembly when the actuation sled assembly is in its retracted position to retain the lock member in the unlocked position.

In aspects of the disclosure, the lock member includes a circular hub portion and the anvil body defines a recess having a cylindrical portion.

In some aspects of the disclosure, the circular hub portion of the lock member is received within the cylindrical portion of the recess to rotatably support the lock member on the anvil body.

In certain aspects of the disclosure, the lock mechanism includes a pin that engages the lock member to retain the lock member within the recess in the anvil body.

In aspects of the disclosure, the lock member includes an arm and an abutment member.

In some aspects of the disclosure, the circular hub portion is positioned on a distal portion of the arm and the abutment member is positioned on a proximal portion of the arm.

In certain aspects of the disclosure, the abutment member has an abutment surface that engages the clamp member when the lock member is in the locked position.

In aspects of the disclosure, the lock member is molded from plastic.

In some aspects of the disclosure, the locked member is stamped from sheet metal.

In certain aspects of the disclosure, the anvil body includes an overhang that is positioned over the recess to retain the lock member within the recess.

Another aspect of this disclosure is directed to an anvil assembly including an anvil and a lock mechanism. The anvil includes an anvil body having a staple forming surface defining staple forming pockets and a longitudinal slot. The staple forming pockets are positioned on opposite sides of the longitudinal slot. The lock mechanism is supported on the anvil body and includes a lock member that is rotatable between a locked position and an unlocked position. In the locked position, the lock member extends at least partially across the longitudinal slot.

Various aspects of the disclosure are described herein below with reference to the drawings, wherein:.

The disclosed stapling device will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. However, it is to be understood that aspects of the disclosure are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. 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 disclosure in virtually any appropriately detailed structure. In addition, directional terms such as front, rear, upper, lower, top, bottom, distal, proximal, and similar terms are used to assist in understanding the description and are not intended to limit the disclosure.

In this description, the term "proximal" is used generally to refer to that portion of the device that is closer to a clinician, while the term "distal" is used generally to refer to that portion of the device that is farther from the clinician. In addition, the term "clinician" is used generally to refer to medical personnel including doctors, nurses, and support personnel.

The disclosed surgical stapling device includes a tool assembly and a drive assembly for actuating the tool assembly. The tool assembly includes an anvil and a cartridge assembly that are movable in relation to each other between open and clamped positions. The cartridge assembly includes a channel member and a staple cartridge that is releasably received within the channel member and replaceable to facilitate reuse of the stapling device. The staple cartridge includes a cartridge body, and an actuation sled assembly which includes a knife. The drive assembly includes a clamp member that is movable through the cartridge body from a retracted position to an advanced position. Movement of the clamp member from its retracted position to its advanced position advances the actuation sled assembly though the cartridge body to move the tool assembly from the open position to the clamped position and to eject staples from the staple cartridge. The anvil supports a lock mechanism that forms an anvil assembly with the anvil. The lock mechanism includes a lock member that is movable from a locked position to an unlocked position in response to movement of the tool assembly from the open position to the clamped position. In the locked position, the lock mechanism obstructs movement of the drive assembly from its retracted to its advanced position to prevent operation of the stapling device. <FIG> illustrate a surgical stapling device according to aspects of the disclosure shown generally as stapling device <NUM> which includes a handle assembly <NUM>, an elongate body <NUM>, and a tool assembly <NUM>. The elongate body <NUM> defines a longitudinal axis "X" (<FIG>). The handle assembly <NUM> includes a body <NUM> that defines a hand grip 18a, a plurality of actuator buttons <NUM>, a rotation knob <NUM>, and an articulation lever <NUM>. The rotation knob <NUM> is rotatably supported on a distal portion of the body <NUM> of the handle assembly <NUM> and supports the elongate body <NUM> to facilitate rotation of the elongate body <NUM> and the tool assembly <NUM> in relation to the handle assembly <NUM> about the longitudinal axis "X". The actuator buttons <NUM> control operation of the various functions of the stapling device <NUM> including approximation, firing, and cutting. The articulation lever <NUM> is rotatably supported on the rotation knob <NUM> and is pivotable to effect articulation of the tool assembly <NUM> in relation to the elongate body <NUM> about an axis transverse to the longitudinal axis "X" of the elongate body <NUM>. Although the stapling device <NUM> is illustrated as an electrically powered stapling device, it is envisioned that the disclosed tool assembly <NUM> would also be suitable for use with manually powered surgical stapling devices and robotically actuated stapling devices. <CIT> discloses a surgical stapling device including a powered handle assembly and <CIT> discloses a surgical stapling device including a manually actuated handle assembly. <CIT> discloses a stapling device that is configured for use with a robotic system.

<FIG> illustrate the tool assembly <NUM> which includes an anvil <NUM> and a cartridge assembly <NUM>. The cartridge assembly <NUM> includes a staple cartridge <NUM> and a channel member <NUM> that receives the staple cartridge <NUM>. The staple cartridge <NUM> is releasably supported within the channel member <NUM> and is replaceable to facilitate reuse of the tool assembly <NUM>. The staple cartridge <NUM> includes a cartridge body <NUM>, an actuation sled <NUM> (<FIG>), and a plurality of staples <NUM> (<FIG>). The cartridge body <NUM> defines a central knife slot <NUM> and staple receiving pockets <NUM>. In aspects of the disclosure, the staple receiving pockets <NUM> are aligned in rows positioned on each side of the central knife slot <NUM>. Although three rows of staple receiving pockets <NUM> are shown in <FIG> on each side of the central knife slot <NUM>, it is envisioned that the cartridge body <NUM> may define one or more rows of staple receiving pockets <NUM> on each side of the central knife slot <NUM>. Each of the staple receiving pockets <NUM> receives a staple <NUM> (<FIG>). Although not shown, the staple cartridge <NUM> also includes pushers that support the staples <NUM> and are engaged by the actuation sled <NUM> (<FIG>) as the actuation sled <NUM> is advanced through the cartridge body <NUM> to eject the staples <NUM> from the cartridge body <NUM>. In aspects of the disclosure, the actuation sled <NUM> includes angled cam surfaces 112a (<FIG>) that engage and lift the pushers (not shown) within the cartridge body <NUM> of the staple cartridge <NUM> to eject the staples <NUM> from the cartridge body <NUM>.

<FIG> illustrate the actuation sled <NUM> of the staple cartridge <NUM> and a clamp member <NUM> of a drive assembly of the stapling device <NUM> (<FIG>). The actuation sled <NUM> supports a knife <NUM> to form an assembly that is movable through the cartridge body <NUM> from a retracted position to an advanced position. The knife <NUM> includes a longitudinal body portion <NUM> and a vertically positioned cutting member <NUM> that extends from the body <NUM> through the central knife slot <NUM> (<FIG>) in the cartridge body <NUM> towards the anvil <NUM>.

<FIG> illustrate the anvil <NUM> of the tool assembly <NUM> which includes an anvil body <NUM> that has a proximal portion and a distal portion. The distal portion of the anvil body <NUM> has a staple forming surface <NUM> that defines staple forming pockets 136a. The staple forming surface <NUM> is movable into juxtaposed alignment with the staple cartridge <NUM> (<FIG>) when the tool assembly <NUM> is moved from the open position to the clamped position to position the staple forming pockets 136a in juxtaposed alignment with the staple receiving pockets <NUM> (<FIG>) of the staple cartridge <NUM>. The anvil body <NUM> defines a channel <NUM> and a longitudinal slot <NUM> that communicates with the channel <NUM>. The channel <NUM> has a proximal portion that is defined by ramped surfaces <NUM> that are positioned on each side of the longitudinal slot <NUM>. The proximal portion of the anvil body <NUM> includes side flanges <NUM> that define openings <NUM>. Each of the openings <NUM> receives a pivot member <NUM> (<FIG>) to pivotably couple the anvil <NUM> to the channel member <NUM> of the cartridge assembly <NUM>.

The stapling device <NUM> (<FIG>) includes a drive assembly including a drive screw <NUM> (<FIG>) and the clamp member <NUM> (<FIG>). As known in the art, the drive screw <NUM> is axially fixed but rotatably supported within the cartridge assembly <NUM>.

<FIG> illustrate the clamp member <NUM> which includes a body <NUM> having a first beam <NUM>, a second beam <NUM>, and a central portion <NUM> that interconnects the first beam <NUM> and the second beam <NUM>. The central portion <NUM> includes a vertical strut <NUM> and a hub <NUM>. The vertical strut <NUM> defines a distal stop surface <NUM> and has a first end that is secured to the first beam <NUM> and a second end that is secured to a first side of the hub <NUM>. The hub <NUM> has a second side that is connected to the second beam <NUM> and defines a threaded through bore <NUM> that receives the drive screw <NUM> (<FIG>). When the drive screw <NUM> is rotated within the cartridge assembly <NUM>, the clamp member <NUM> is driven longitudinally along the drive screw <NUM> within the staple cartridge <NUM> between retracted and advanced positions.

The first beam <NUM> is received within the channel <NUM> (<FIG>) defined within the anvil body <NUM> of the anvil <NUM>. When the clamp member <NUM> moves from its retracted position towards its advanced position, the first beam <NUM> of the clamp member <NUM> engages the ramped surfaces <NUM> of the anvil body <NUM> to pivot the anvil <NUM> in relation to the cartridge assembly <NUM> from the open position to the clamped position. The first beam <NUM> of the clamp member <NUM> includes a distally extending finger 156a that has a downwardly extending projection <NUM> that slides along the longitudinal slot <NUM> (<FIG>) of the anvil <NUM> to push tissue from within the longitudinal slot <NUM>.

The second beam <NUM> is positioned to move along an outer surface 108a (<FIG>) of the channel member <NUM> (<FIG>). In aspects of the disclosure, the outer surface 108a of the channel member <NUM> defines a groove (not shown) that receives the second beam <NUM> to guide the second beam <NUM> along the channel member <NUM>. Engagement of the first and second beams <NUM> and <NUM> with the anvil <NUM> and the cartridge assembly <NUM>, respectively, sets a maximum tissue gap between the staple forming surface <NUM> of the anvil <NUM> and the staple cartridge <NUM> (<FIG>) as the clamp member <NUM> moves through the tool assembly <NUM>.

When the staple cartridge <NUM> is received within the channel member <NUM> of the cartridge assembly <NUM>, the clamp member <NUM> is positioned proximally of and adjacent to the actuation sled <NUM>. In this position, the cutting member <NUM> of the knife <NUM> is positioned adjacent to the distal stop surface <NUM> (<FIG>) of the vertical strut <NUM> of the clamp member <NUM>.

<FIG> illustrate a lock mechanism <NUM> of the tool assembly <NUM> which includes a lock member <NUM>, a biasing member <NUM>, and a pin <NUM>. The lock mechanism <NUM> is supported on the anvil body <NUM> of the anvil <NUM> to form an anvil assembly. The lock member <NUM> includes a circular hub portion <NUM>, an arm <NUM> that extends proximally from the hub portion <NUM>, an abutment member <NUM>, and a biasing member seat <NUM>. The lock member <NUM> is received within a recess <NUM> (<FIG>) defined in the anvil body <NUM>. The recess <NUM> in the anvil body <NUM> has a distal portion 196a that is cylindrical and receives the circular hub portion <NUM> of the lock member <NUM> to facilitate rotation of the lock member <NUM> within the recess <NUM>. The anvil body <NUM> also defines a transverse through bore <NUM> (<FIG>) and a groove <NUM>. The through bore <NUM> intersects the recess <NUM>. The pin <NUM> is received within the through bore <NUM> and engages a flat 188a (<FIG>) on the distal portion of the circular hub portion <NUM> of the lock member <NUM> (<FIG>) to retain a distal end of the lock member <NUM> within the recess <NUM> of the anvil body <NUM>. The anvil body <NUM> also includes an overhang <NUM> (<FIG>) that extends over the proximal portion of the lock member <NUM> to retain the proximal end of the lock member <NUM> within the recess <NUM> of the anvil body <NUM>.

In an alternate version of the disclosure shown in <FIG>, the pin <NUM> is replaced by a second overhang <NUM>' that is formed on the anvil body <NUM>'. The second overhang <NUM>' also retains the lock member <NUM>' within the recess <NUM>' of the anvil body <NUM>'.

The lock member <NUM> includes a transverse blind bore <NUM> (<FIG>) that is aligned with the biasing member seat <NUM>. The biasing member <NUM> of the lock mechanism <NUM> is received within the groove <NUM> (<FIG>) in the anvil body <NUM> and extends into the blind bore <NUM> and into engagement with the biasing member seat <NUM> of the lock member <NUM> to urge the lock member <NUM> towards a locked position described in further detail below. According to the invention, the biasing member <NUM> includes a coil spring although the use of a variety of different biasing members is envisioned.

The abutment member <NUM> of the lock member <NUM> extends upwardly from the arm <NUM> of the lock member <NUM> and from the anvil body <NUM> (as viewed in <FIG>) towards the cartridge assembly <NUM> (<FIG>). The abutment member <NUM> is positioned adjacent the longitudinal slot <NUM> (<FIG>) of the anvil <NUM> and includes a tapered or angled engagement surface <NUM> and an abutment surface <NUM>. The lock member <NUM> is rotatable about an axis "Z" (<FIG>) defined by the circular hub portion <NUM> from an unlocked position (<FIG>) to a locked position (<FIG>). In the locked position, the abutment member <NUM> extends at least partially across the longitudinal slot <NUM> of the anvil <NUM>.

<FIG> illustrate the tool assembly <NUM> (<FIG>) in the clamped position with the lock mechanism <NUM> in the unlocked position. When a new staple cartridge <NUM> (<FIG>), i.e., unfired, is positioned within the channel member <NUM> of the cartridge assembly <NUM> and the tool assembly <NUM> is moved to the clamped position, the staple forming surface <NUM> (<FIG>) of the anvil <NUM> moves into juxtaposed alignment with the staple cartridge <NUM>. As the anvil <NUM> pivots in relation to the staple cartridge <NUM> (<FIG>), the angled engagement surface <NUM> (<FIG>) of the abutment <NUM> of the lock member <NUM> engages the cutting member <NUM> of the knife <NUM>. This engagement rotates the lock member <NUM> of the lock mechanism <NUM> about the pivot axis "Z" (<FIG>) in the direction of arrow "A" in <FIG> against the urging of the biasing member <NUM> from the locked position (<FIG>) to the unlocked position (<FIG>). In the unlocked position, the lock member <NUM> is engaged with the cutting member <NUM> of the knife <NUM> to retain the abutment surface <NUM> of the abutment member <NUM> in a position outwardly of the distal stop surface <NUM> of the clamp member <NUM>. In this position, the stapling device <NUM> (<FIG>) can be fired.

<FIG> and <FIG> illustrate the tool assembly <NUM> in the clamped position and the lock mechanism <NUM> in the locked position. When the stapling device <NUM> (<FIG>) is fired, the clamp member <NUM> is advanced through the tool assembly <NUM> from a retracted position to an advanced position. As the clamp member <NUM> moves through the tool assembly <NUM>, the clamp member <NUM> abuts and advances the actuation sled <NUM> and the knife <NUM> (which is supported on the actuation sled <NUM>) through the staple cartridge <NUM>. Since the actuation sled <NUM> is only in abutting relationship with the clamp member <NUM>, when the clamp member <NUM> is moved from the advanced position back to the retracted position, the actuation sled <NUM> (<FIG>) and the knife <NUM> remain in the distal end of the staple cartridge <NUM>. As such, after the stapling device <NUM> (<FIG>) is fired and the clamp member <NUM> is returned to the retracted position, the cutting member <NUM> of the knife <NUM> is no longer positioned to obstruct movement of the lock member <NUM> of the lock mechanism <NUM> from the unlocked position to the locked position. Thus, the lock member <NUM> is moved by the biasing member <NUM> from the unlocked position (<FIG>) to the locked position (<FIG> ) in which the abutment surface <NUM> of the lock member <NUM> is positioned in alignment with the distal stop surface <NUM> of the clamp member <NUM> to prevent distal movement (or readvancement) of the clamp member <NUM> within the staple cartridge <NUM>.

<FIG> and <FIG> illustrate an alternative version of the lock mechanism shown generally as lock mechanism <NUM>. The lock mechanism <NUM> is substantially like lock mechanism <NUM> (<FIG>) except that the pin <NUM> (<FIG>) is not included in the lock assembly <NUM> and the circular hub portion <NUM> of the lock member <NUM> (<FIG>) is replaced with a pivot member <NUM> (<FIG>). In this version of the lock mechanism <NUM>, the distal portion of the lock member <NUM> defines a through bore <NUM> and the pivot member <NUM> includes a protrusion <NUM> that is fixedly received within the through bore <NUM>. In aspects of the disclosure, the through bore <NUM> and the protrusion <NUM> are not circular to prevent rotation of the protrusion <NUM> within the through bore <NUM>. In some aspects of the disclosure, the through bore <NUM> of the lock member <NUM> and the protrusion <NUM> of the pivot member <NUM> have oval configurations. The pivot member <NUM> also includes a head portion <NUM> (<FIG>) and a circular hub portion <NUM>. The circular hub portion <NUM> of the pivot member <NUM> is rotatably received within the distal portion 196a of the recess <NUM> in the anvil body <NUM>. The recess <NUM> extends through the anvil body <NUM> such that the circular hub portion <NUM> is received within the distal portion 196a of the recess <NUM>. The head portion <NUM> of the pivot member <NUM> engages the outer surface of the anvil body <NUM> to prevent the pivot member <NUM> from passing through the anvil body <NUM>.

The lock mechanism <NUM> also includes a biasing member <NUM> that is like biasing member <NUM> of lock mechanism <NUM> (<FIG>) to urge the lock member <NUM> towards the locked position. The lock mechanism <NUM> functions in a substantially similar manner to the lock mechanism <NUM> and will not be described in further detail herein.

In aspects of the disclosure, the lock members <NUM>, <NUM> of the lock mechanisms <NUM>, <NUM> can be molded from a suitable material, e.g., plastic. In an alternate version of the lock assembly, as shown in <FIG>, the lock member shown generally as lock member <NUM> can be stamped from sheet metal.

Each of the lock mechanisms disclosed is supported on the anvil of the tool assembly of the stapling device. By positioning the lock mechanism on the anvil, the lock mechanism remains in a locked position until the tool assembly is moved to the clamped position. Although each of the lock mechanisms is shown for use with a stapling device having a staple cartridge that includes a knife, it is envisioned that the lock mechanisms are also suitable for use with stapling devices that do not include a knife. In such devices, the lock members of the lock mechanisms would engage the actuation sled of the staple cartridge to retain the lock mechanism in the unlocked position prior to actuation of the stapling device.

Claim 1:
A surgical stapling device comprising:
an elongate body having a proximal portion and a distal portion;
a tool assembly supported on the distal portion of the elongate body, the tool assembly including:
a cartridge assembly including a channel member and a staple cartridge, the staple cartridge removably received within the channel member and including a cartridge body, staples, and an actuation sled assembly including an actuation sled, the actuation sled assembly movable through the cartridge body between retracted and advanced positions;
an anvil including an anvil body that is coupled to the cartridge assembly such that the tool assembly is movable between open and clamped positions; and
a lock mechanism supported on the anvil, the lock mechanism including a lock member that is rotatable between a locked position and an unlocked position in response to movement of the tool assembly from the open position to the clamped position; and
a drive assembly including a clamp member, the clamp member movable in relation to the tool assembly between retracted and advanced positions, wherein the lock member is positioned to prevent movement of the clamp member from the retracted position to the advanced position in the locked position when the tool assembly is in the clamped position, wherein the lock member is biased towards the locked position wherein the lock mechanism includes a biasing member to urge the lock member towards the locked position,
characterised in that
the biasing member includes a coil spring; and
in that the actuation sled assembly includes a knife that is supported on the actuation sled;
wherein the lock member engages the knife of the actuation sled assembly when the actuation sled assembly is in its retracted position to retain the lock member in the unlocked position.