Patent Description:
Surgical instruments for, e.g., applying staples, clips, or other fasteners to tissue, are well known. Generally, surgical instruments include an actuation unit, e.g., a handle assembly for actuating the instrument, an elongate shaft for accessing a body cavity, and a tool assembly disposed at a distal end of the elongate shaft. The surgical instruments may be manual or powered. Typically, one or more drive assemblies extend from the handle assembly, through the elongate shaft of the surgical instrument for effecting at least one function of the end effector, e.g., clamping, stapling, or cutting.

It would be beneficial to have a surgical instrument with one or more mechanical lockout mechanisms to inhibit operation of the surgical instrument prior to certain conditions being met and/or to prevent a second or subsequent operation of the surgical instrument. <CIT>, <CIT>, <CIT> and <CIT> disclose surgical instruments with lockout mechanisms, generally provided in the handle part of the instrument. Document <CIT> discloses a surgical instrument according to the preamble of claim <NUM>.

The present invention provides a surgical instrument as set out in the appended set of claims. The surgical instrument includes a first drive assembly including a first drive gear; and a lockout mechanism positioned for releasable engagement with the first drive assembly to inhibit rotation of the first drive gear. The lockout mechanism includes a pawl and an actuator means for moving the pawl from a first position in engagement with the first drive gear to a second position spaced from the first drive gear.

In embodiments, the pawl includes a plurality of teeth and the first drive gear includes a plurality of teeth. The plurality of teeth of the pawl may engage the plurality of teeth of the first drive gear when the pawl is in the first position. The pawl may pivot from the first position to the second position. The surgical instrument includes an adapter assembly. The first drive assembly and the lockout mechanism are disposed within the adapter assembly. The actuator may include a motor, a servo, or an electromagnet.

The surgical instrument includes a handle assembly. The adapter assembly is releasably secured to the handle assembly. In addition, the surgical instrument further includes an end effector releasably secured to the adapter assembly. The end effector may include a loading unit and an anvil assembly.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiments given below, serve to explain the principles of the disclosure, wherein:.

Embodiments of the presently disclosed lockout mechanisms 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. As is common in the art, the term "proximal" refers to that part or component closer to the user or operator, e.g. surgeon or clinician, while the term "distal" refers to that part or component farther away from the user.

Referring initially to <FIG>, an adapter assembly including a lockout mechanism according to an embodiment of the present disclosure, shown generally as adapter assembly <NUM>, is a component of a surgical stapling instrument <NUM>. The surgical stapling instrument <NUM> further includes a powered handle assembly <NUM>, and an end effector <NUM>. As shown, the end effector <NUM> includes a loading unit <NUM>, and an anvil assembly <NUM>. Although shown and described with reference to surgical stapling instrument <NUM>, the aspects of the present disclosure may be modified for use with surgical instruments having one or more drive assemblies for effecting actuation of an end effector. For a detailed description of exemplary powered surgical stapling instruments, please refer to commonly owned <CIT> and <CIT> ("the '<NUM> patent" and "the '<NUM> patent", respectively).

The adapter assembly <NUM> of the surgical stapling instrument <NUM> will only be described to the extent necessary to fully disclose the aspects of the present disclosure. For a detailed description of exemplary adapter assemblies, please refer to commonly owned <CIT> ("the '<NUM> publication), <NUM>/<NUM> ("the '<NUM> publication"), and <CIT> ("the '<NUM> publication").

With continued reference to <FIG>, the adapter assembly <NUM> includes a proximal portion <NUM> configured for operable connection to the handle assembly <NUM> (<FIG>) and a distal portion <NUM> configured for operable connection to the loading unit <NUM> (<FIG>). Although shown and described as forming an integral unit, it is envisioned that the proximal and distal portions <NUM>, <NUM> may be formed as separate units that are releasably securable to one another.

With reference to <FIG>, the proximal portion <NUM> of the adapter assembly <NUM> includes a rotation knob assembly <NUM>. The rotation knob assembly <NUM> includes a base <NUM>, and a rotation knob <NUM> rotatably secured to the base <NUM>. The base <NUM> is configured to operably connect the adapter assembly <NUM> with the handle assembly <NUM>.

With particular reference to <FIG>, a drive coupling assembly <NUM> is operably disposed within the base <NUM> of the rotation knob assembly <NUM>. The drive coupling assembly <NUM> engages first, second and third drive shafts (not shown) of the handle assembly <NUM> (<FIG>). A drive transfer assembly <NUM> is disposed within the rotation knob <NUM> of the rotation knob assembly <NUM> and is operably secured to the drive coupling assembly <NUM>. The drive coupling assembly <NUM> and drive transfer assembly <NUM> remain rotationally fixed relative to the handle assembly to which adapter assembly <NUM> is attached, e.g., handle assembly <NUM>.

The drive coupling assembly <NUM> and the drive transfer assembly <NUM> together form first, second, and third drive assemblies <NUM>, <NUM>, <NUM>. The first, second, and third drive assemblies <NUM>, <NUM>, <NUM> may each effect a different operation of an attached end effector, e.g., end effector <NUM> (<FIG>). For example, the first drive assembly <NUM> may effect tissue stapling, the second drive assembly <NUM> may effect tissue cutting, and the third drive assembly <NUM> may effect tissue clamping.

With particular reference to <FIG>, in one embodiment of the present disclosure, a lockout mechanism <NUM> includes a pawl <NUM> operably disposed within the rotation knob assembly <NUM> of the adapter assembly <NUM>. The pawl <NUM> is pivotally supported relative to a first drive gear <NUM> of the third drive assembly <NUM>. The pawl <NUM> includes a plurality of teeth 164a on a free end <NUM>. The plurality of teeth 164a is configured to engage the first drive gear <NUM> of the third drive assembly <NUM>. In embodiments, and as shown, the plurality of teeth 164a of the pawl <NUM> is configured to inhibit rotation of the first drive gear <NUM> in a first direction, e.g., clockwise, and permit rotation of the first drive gear <NUM> in a second direction, e.g., counter-clockwise. In this manner, the lockout mechanism <NUM> may permit retraction of the third drive assembly <NUM> while preventing advancement of the third drive assembly <NUM>. Alternatively, the plurality of teeth 164a of the pawl <NUM> may be configured to inhibit rotation of the first drive gear <NUM> in both the first and second directions.

Although shown and described with the pawl <NUM> in engagement with the first drive gear <NUM> of the third drive assembly <NUM>, it is envisioned that the lockout mechanism <NUM> may be modified to include one or more pawls that engage any of the gears of any combination of the first, second, and third drive assemblies <NUM>, <NUM>, <NUM>.

Turning to <FIG>, when the handle assembly <NUM> (<FIG>) of the surgical stapling instrument <NUM> is programmed to detect if certain parameters are satisfied, e.g., proper loading of a trocar assembly <NUM> within the adapter assembly <NUM>, and when satisfied, the handle assembly <NUM> activates the lockout mechanism <NUM> to disengage the pawl <NUM> from the first drive gear <NUM> of the third drive assembly <NUM> to permit rotation of the first drive gear <NUM>. In embodiments, the lockout mechanism <NUM> includes an actuator <NUM>, e.g., a motor, servo, electromagnet or other suitable means for pivoting the pawl <NUM> out of engagement with the first drive gear <NUM>. Once the pawl <NUM> disengages from the first drive gear <NUM>, the third drive assembly <NUM> operates in a traditional manner.

The handle assembly <NUM> may be programmed to reengage the pawl <NUM> of the lockout mechanism <NUM> with the first drive gear <NUM> of the third drive assembly <NUM> subsequent to firing of the surgical stapling instrument <NUM> to prevent reuse of the surgical stapling instrument <NUM>. Similarly, the and/or at any time during the stapling procedure when locking of the third drive assembly <NUM> may become desired, e.g., malfunction of the surgical stapling instrument <NUM> (<FIG>).

With reference now to <FIG>, a lockout mechanism falling outside the scope of the present invention will be shown and described with reference to an adapter assembly <NUM>, and a removable trocar assembly <NUM> releasably disposable within a distal portion <NUM> of the adapter assembly <NUM>. The adapter assembly <NUM> is substantially similar to adapter assembly <NUM> described hereinabove and will only be described in detail as relates to the differences therebetween.

The trocar assembly <NUM> includes a housing <NUM> and a trocar member <NUM> selectively extendable from the housing <NUM>. The housing <NUM> defines a pair of openings <NUM> (<FIG>). As will be described in further detail below, the housing <NUM> of the trocar assembly <NUM> is configured to be engaged by a retaining mechanism <NUM> when the trocar assembly <NUM> is fully received and seated within the distal portion <NUM> of the adapter assembly <NUM> to secure the trocar assembly <NUM> within the adapter assembly <NUM>.

With reference now to <FIG> and <FIG>, the retaining mechanism <NUM> of the adapter assembly <NUM> is disposed between first and second drive members <NUM>, <NUM>, <NUM>, <NUM> of respective first and second drive assemblies <NUM>, <NUM>. The first and second drive assemblies <NUM>, <NUM> are operably connected to first and second drive members (not shown) in a proximal portion <NUM> of the adapter assembly <NUM> for effecting operation of an end effector, e.g., the end effector <NUM> (<FIG>), to perform first and second functions. More particularly, the first and second drive members <NUM>, <NUM>, <NUM>, <NUM> of the respective first and second drive assemblies <NUM>, <NUM> are configured for longitudinal movement within the distal portion <NUM> of the adapter assembly <NUM>. Advancement of the first drive assembly <NUM> effects tissue stapling, and advancement of the second drive assembly <NUM> effects tissue cutting.

The first and second drive assemblies <NUM>, <NUM> will only be described to the extent necessary to fully disclose the aspects of the present disclosure. For a detailed description of exemplary drive assemblies, please refer to the '<NUM> publication.

With additional reference to <FIG>, the first drive member <NUM> of the first drive assembly <NUM> includes an elongate band 222a and a flange portion 222b extending outwardly from a proximal portion of the elongate band 222a. As will be described in further detail below, the flange portion 222b of the first drive member <NUM> is configured to be engaged by a wire cam or spring clip <NUM> of a lockout mechanism <NUM> to inhibit advancement of the first drive assembly <NUM> when the trocar assembly <NUM> is not fully received and seated within the adapter assembly <NUM>.

With continued reference to <FIG> and <FIG>, and additional reference to <FIG>, the retaining mechanism <NUM> of the adapter assembly <NUM> includes a retaining block <NUM>, a wire cam <NUM> (<FIG>), a pair of retaining members <NUM> (<FIG>), and a release button <NUM> (<FIG>). The retaining block <NUM> of the retaining mechanism <NUM> defines a central opening <NUM> for receiving the trocar assembly <NUM>, a pair of opposed cylindrical openings 241a in communication with the central opening <NUM> for receiving the retainer members <NUM>, and a channel or slot 241b extending about a perimeter of the retaining block <NUM> and through the cylindrical openings 241a in the retaining block <NUM> for receiving the wire cam <NUM>. The retainer members <NUM> of the retaining mechanism <NUM> are supported within the cylindrical openings 241a by the wire cam <NUM> and are configured to be received within the openings <NUM> (<FIG>) in the housing <NUM> of the trocar assembly <NUM> when the trocar assembly <NUM> is fully received and seated within the distal portion <NUM> of the adapter assembly <NUM>.

The wire cam <NUM> of the retaining mechanism <NUM> includes a substantially U-shaped body 244a having a pair of opposed angled sections 244b and free ends 244c. The wire cam <NUM> is received within the channel 241b of the retaining block <NUM> and is moveable between a first position (<FIG>) when the trocar assembly <NUM> is partially received within the distal portion <NUM> of the adapter assembly <NUM>, e.g., the retaining members <NUM> are not aligned with the openings <NUM> in the housing <NUM> of the trocar assembly <NUM>, and a second position (<FIG>) when the trocar assembly <NUM> is fully received within the distal portion <NUM> of the adapter assembly <NUM>, e.g., the retaining members <NUM> are aligned with and received in the openings <NUM> in the housing <NUM>.

With particular reference to <FIG> and <FIG>, when the wire cam <NUM> of the retaining mechanism <NUM> is in the first position, the free ends 244c of the wire cam <NUM> extend beyond the retainer block <NUM> of the retaining mechanism <NUM>. The first drive member <NUM> of the first drive assembly <NUM> and the retaining block <NUM> of the retaining assembly <NUM> are configured such that one of the free ends 244c of the wire cam <NUM> of the retainer assembly <NUM> engages the flange 222b of the first drive member <NUM> to form the lockout mechanism <NUM>. The lockout mechanism <NUM> inhibits operation of the first drive assembly <NUM>, e.g., advancement of the first drive member <NUM>. Although shown with only one of the free ends 244c of the wire cam <NUM> engaging the first drive member <NUM> of the first drive assembly <NUM>, it is envisioned that the first drive member <NUM> may be configured to engage both free ends 244c of the wire cam <NUM>. The engagement of the first drive member <NUM> of the first drive assembly <NUM> with the flange 222b of the first drive member <NUM> may provide sufficient resistance to movement that the handle assembly <NUM> (<FIG>) detects and identifies that the trocar assembly <NUM> is not fully received and properly seated within the adapter assembly <NUM>.

The retaining members <NUM> of the retaining mechanism <NUM> are supported on the angled portions 244b of the wire cam <NUM>. The retaining members <NUM> may include an inclined inner surface 246a (<FIG>) to facilitate receipt of the trocar assembly <NUM> therebetween. The retaining members <NUM> each define an opening <NUM> through which the respective angled section 244b of the wire cam <NUM> is received. The wire cam <NUM> and the retaining members <NUM> are configured such that when the trocar assembly <NUM> is not fully received within the distal portion <NUM> of the adapter assembly <NUM>, the wire cam <NUM> is maintained in the first position (<FIG>), with the free ends 244c of the wire cam <NUM> extending beyond the retaining block <NUM>. In this manner, at least one of the free ends 244c of the wire cam <NUM> engages the first drive member <NUM> of the first drive assembly <NUM> to inhibit advancement of the first drive member <NUM>.

As shown in <FIG> and <FIG>, when the trocar assembly <NUM> is received within the distal portion <NUM> of the adapter assembly <NUM> and when the openings <NUM> in the housing <NUM> of the adapter assembly <NUM> are not aligned with the retaining members <NUM>, the housing <NUM> of the trocar assembly <NUM> biases the retaining members <NUM> outward, as indicated by arrows "A" in <FIG>. The angled sections 244c of the wire cam <NUM> and the openings <NUM> in the retaining members <NUM> are configured such that when the retaining members <NUM> are biased outwardly through contact with the housing <NUM> of the trocar assembly <NUM>, the cam wire <NUM> is biased upwardly, as indicated by arrows "B" in <FIG>, to cause the free ends 244c of the cam wire <NUM> to extend beyond the retaining block <NUM> and into the path of the first drive member <NUM> of the first drive assembly <NUM>.

With reference to <FIG> and <FIG>, when the trocar assembly <NUM> is fully received and properly seated within the distal portion <NUM> of the adapter assembly <NUM> (<FIG>), e.g., the openings <NUM> of the housing <NUM> of the trocar assembly <NUM> are aligned with the retaining members <NUM> of the retaining mechanism <NUM>, the retaining members <NUM> move within the openings <NUM> in the housing <NUM> of the trocar assembly <NUM>, as indicated by arrows "C" in <FIG>. Movement of the retaining members <NUM> into the openings <NUM> of the housing <NUM> moves the cam wire <NUM> downwardly (as illustrated in <FIG>) such that the free ends 244c of the cam wire <NUM> are retracted within the retaining block <NUM>. Retraction of the free ends 244c of the cam wire <NUM> within the retaining block <NUM> clears a path for the first drive member <NUM> of the first drive assembly <NUM>. The adapter assembly <NUM> then operates in a traditional manner.

Following a stapling procedure with adapter assembly <NUM>, the trocar assembly <NUM> may be released from the adapter assembly <NUM> by pressing the retaining button <NUM> of the retaining mechanism <NUM> to cause the cam wire <NUM> to move upwardly (as illustrated in <FIG>) and result in the retaining members <NUM> moving outwardly from within the openings <NUM> in the housing <NUM> of the trocar assembly <NUM>. Once the retaining members <NUM> clear the openings <NUM> in the housing <NUM>, the trocar assembly <NUM> may be removed from within the distal portion <NUM> of the adapter assembly <NUM>.

With reference now to <FIG>, another lockout mechanism falling outside the scope of the present invention is shown generally as lockout mechanism <NUM>. As shown, the lockout mechanism <NUM> is configured to inhibit advancement of a drive member <NUM> of a drive assembly <NUM>. More particularly, the lockout mechanism <NUM> includes a locking member <NUM> that is pivotally secured relative to the drive member <NUM>. The locking member <NUM> is configured to be received within a cutout <NUM> in the first drive member <NUM>. The cutout <NUM> is defined by a vertical distal facing surface 314a and a sloped proximal facing surface 314b. When the locking member <NUM> is received within the cutout <NUM> and in engagement with the vertical distal facing surface 314a, the locking member <NUM> inhibits movement of the drive member <NUM>.

The lockout mechanism <NUM> further includes an electromagnet <NUM> disposed adjacent the locking member <NUM>. When activated, the electromagnet <NUM> causes the locking member <NUM> to pivot out of the cutout <NUM> in the drive member <NUM>, thereby permitting advancement of the drive member <NUM>. Although shown as including an electromagnet <NUM>, it is envisioned that the locking member <NUM> may be moved with a motor, solenoid, or other mechanism. Although shown as being pivoted out of engagement with the drive member <NUM>, it is envisioned that the locking member <NUM> may instead by retracted or otherwise moved in a linear manner from within the cutout <NUM>.

With particular reference to <FIG>, a distance "x" between the vertical distal facing surface 314a of the drive member <NUM> and the sloped proximal facing surface 314b of the drive member <NUM> determines the distance the drive member <NUM> may be advanced before the lockout mechanism <NUM> engages. The greater the distance "x", the greater the distance the drive member <NUM> may be advanced prior to the lockout mechanism <NUM> engaging.

Turning to <FIG>, another lockout mechanism falling outside the scope of the present invention is shown generally as lockout mechanism <NUM>. The lockout mechanism <NUM> includes a housing <NUM>, a plunger member <NUM>, a biasing member, e.g., spring <NUM>, and an electromagnet <NUM>. Although shown including a housing <NUM>, it is envisioned that the lockout mechanism <NUM> may be incorporated directly into an adapter assembly, e.g., adapter assembly <NUM>.

The housing <NUM> of the locking mechanism <NUM> includes a cylindrical recess <NUM>, a cutout <NUM>, and a passage <NUM> extending between the cylindrical recess <NUM> and the cutout <NUM>. The plunger member <NUM> includes a head portion <NUM> and an elongate body portion <NUM>. The head portion <NUM> is received within the cylindrical recess <NUM> and the elongate body portion <NUM> extends through the passage <NUM> into the cutout <NUM>. The biasing member, e.g., spring <NUM>, is disposed within the cylindrical recess <NUM> and biases the plunger member <NUM> in a first direction, as indicated by arrow "F" in <FIG>, into an extended or locked position. In the locked position, the elongate body portion <NUM> of the plunger member <NUM> extends from the passage <NUM> into the cutout <NUM>.

The electromagnet <NUM> is disposed adjacent the cylindrical recess <NUM> opposite the passage <NUM>. Activation of the electromagnet <NUM> retracts the plunger member <NUM> against the bias of the spring <NUM>, as indicated by arrow "G" in <FIG>, into a retracted or unlocked position. When the plunger member <NUM> is in the unlocked position, the elongate body portion <NUM> of the plunger member <NUM> is retracted from within the cutout <NUM> of the housing <NUM> of the locking mechanism <NUM> such that the cutout is unobstructed.

In operation, the locking mechanism <NUM> is positioned within a surgical instrument, e.g., surgical stapling instrument <NUM> (<FIG>), such that the cutout <NUM> of the housing <NUM> is in alignment with a path (not shown) of a drive member (not shown) or connecting element <NUM>. When the plunger member <NUM> is in the locked position, the elongate body portion <NUM> of the plunger member <NUM> is disposed within the cutout <NUM>, thereby obstructing the path of the drive member and/or connector member <NUM> and preventing advancement of the drive member through the housing <NUM> of the locking mechanism <NUM> and/or connection of the connector member <NUM> with the housing <NUM>.

As noted above, activation of the electromagnet <NUM> causes the plunger member <NUM> to retract to the unlocked position (<FIG>), thereby clearing the path through the cutout <NUM> in the housing <NUM>. In this manner, the drive member (not shown) is able to pass through the housing <NUM> unobstructed. Similarly, the connector member <NUM> is able to be received within the cutout <NUM> in the housing <NUM> of the locking mechanism <NUM> to secure the connector member <NUM> with the housing <NUM>.

With reference now to <FIG>, a locking mechanism falling outside the scope of the present invention is shown generally as locking mechanism <NUM>. The locking mechanism <NUM> is substantially similar to locking mechanism <NUM> described hereinabove, and will only be described in detail as relates to the difference therebetween.

In the locking mechanism <NUM>, a plunger member <NUM> is maintained in a retracted or unlocked position (<FIG>) within a cylindrical recess <NUM> of a housing <NUM> by a biasing member, e.g., spring <NUM>, as indicated by arrow "G" in <FIG>. When in the unlocked position, an elongate body portion <NUM> of the plunger member <NUM> obstructs a cutout <NUM> in the housing <NUM> to prevent advancement of a drive member (not shown) and/or preventing receipt of a connector member <NUM> within the cutout <NUM>.

Claim 1:
A surgical instrument (<NUM>) comprising:
an adapter assembly (<NUM>), the adapter assembly including a proximal portion (<NUM>) configured for operable connection to a handle assembly (<NUM>) and a distal portion (<NUM>) configured for operable connection to an end effector (<NUM>), the adapter assembly comprising a rotation knob assembly (<NUM>) including a base (<NUM>) and a rotation knob (<NUM>) rotatably secured to the base; the adapter assembly further comprising a drive coupling assembly (<NUM>) disposed within the rotation knob assembly (<NUM>), and a drive assembly (<NUM>) including a first drive gear (<NUM>);
characterized by
the rotation knob assembly (<NUM>) including a lockout mechanism (<NUM>) positioned for releasable engagement with the drive assembly (<NUM>) to inhibit rotation of the first drive gear (<NUM>), the lockout mechanism including a pawl (<NUM>) and an actuator (<NUM>) for moving the pawl from a first position in engagement with the first drive gear (<NUM>) to a second position spaced from the first drive gear.