Patent Description:
The present application claims the benefit of and priority to <CIT>.

The present application is also a Continuation-in-Part Application which claims the benefit of and priority to <CIT>.

The present disclosure relates to powered surgical devices. More specifically, the present disclosure relates to reusable handheld electromechanical surgical devices including trocar locks, and trocar connection indicators.

Circular stapling instruments for performing surgical procedures such as anastomoses, hemorrhoidectomies, and mucosectomies are well known. These devices include an anvil assembly having a center rod and an anvil head supported on the center rod. The center rod of the anvil assembly is attachable to a trocar of the circular stapling instrument which enable linear translation of the anvil assembly. Typically, during a surgical procedure, the tool assembly of the circular stapling instrument is inserted into a tubular section or sections of tissue to join the tissue sections or remove diseased or damaged tissue from within the tissue section. Following a surgical procedure, it is desirable to reprocess the circular stapling instrument in order to minimize overall costs of the surgical procedures. The reprocessing typically requires cleaning of the circular stapling instrument via autoclaving and the like. In order to improve the efficiency of the reprocessing, removability of the trocar is desirable.

Accordingly, in view thereof, it is desirable to provide locks and indicators which alert the end user (e.g., doctor, nurse, clinician, etc.) that a trocar is properly attached to the underlying circular stapling instrument.

Document <CIT> relates to circular anastomosis instruments, particularly, with instruments intended to be reused and sterilized in whole or in part. In one embodiment, a surgical circular fastener apparatus includes an elongated body defining a longitudinal axis and having proximal and distal ends, a fastener cartridge disposed adjacent the distal end of the body, an anvil retainer or trocar releasably mounted relative to the fastener cartridge and a manually operably release configured to move between ` a first position corresponding to a secured condition of the anvil retainer relative to the fastener cartridge and a second position corresponding to a release condition of the anvil retainer relative to the fastener cartridge. The anvil retainer or trocar may be couplable to an anvil assembly. The elongated body includes a release housing with the manually operable release being mounted for movement relative to the release housing. The release housing may include at least one lock. The at least one lock may be operatively coupled to the manually operable release and configured to move between a locked position in secured engagement with the anvil retainer to prevent removal of the anvil retainer relative to the fastener cartridge upon movement of the manually operable release to the first position, and an unlocked position released from the anvil retainer to permit removal or mounting of the anvil retainer relative to the fastener cartridge upon movement of the manually operable release to the second position.

The invention is defined by appended claim <NUM>.

Embodiments of the present disclosure are described herein with reference to the accompanying drawings, wherein:.

Embodiments of the present disclosure are now 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 used herein the term "proximal" refers to a portion of a surgical device, or component thereof, closer to the user, and the term "distal" refers to a portion of the surgical device, or component thereof, farther from the user.

Turning now to <FIG>, a surgical device <NUM>, in accordance with an embodiment of the present disclosure, is in the form of a powered handheld electromechanical instrument. The surgical device includes a handle assembly <NUM>, an adapter assembly <NUM>, a reload <NUM>, and an anvil assembly <NUM>. The handle assembly <NUM> is configured for selective connection with the adapter assembly <NUM> and, in turn, the adapter assembly <NUM> is configured for selective connection with the reload <NUM>.

The handle assembly <NUM>, the adapter assembly <NUM>, and the reload <NUM> will only further be described to the extent necessary to disclose aspects of the present disclosure. For a detailed description of the structure and function of exemplary handle assemblies, adapter assemblies, and reloads, reference may be made to commonly owned <CIT> and <CIT>.

With reference now to <FIG>, the handle assembly <NUM> includes a power handle <NUM> and an outer or shell housing <NUM> configured to selectively receive and encase the power handle <NUM>. The shell housing <NUM> includes a proximal half-section 110a and a distal half-section 110b that are couplable together. The shell housing <NUM> includes a plurality of actuators <NUM> (e.g., finger-actuated control buttons, knobs, toggles, slides, interfaces, and the like) for activating various functions of the surgical device <NUM> (<FIG>) upon application of a respective force thereto.

The distal half-section 110b of the shell housing <NUM> defines a connecting portion <NUM> (e.g., a recess) configured to accept or receive a corresponding drive coupling assembly <NUM> (<FIG>) of the adapter assembly <NUM>. A sterile barrier plate assembly <NUM> is selectively supported in the distal half-section 110b of the shell housing <NUM> behind the connection portion <NUM>. The plate assembly <NUM> includes a plate <NUM> rotatably supporting three coupling shafts 124a, 124b, 124c, and having an electrical connector <NUM> supported thereon. The electrical connector <NUM> includes a chip and defines a plurality of contact paths each including an electrical conduit for extending an electrical connection across the plate <NUM>. When the plate assembly <NUM> is disposed within the shell housing <NUM>, distal ends of the coupling shafts 124a, 124b, 124c and the electrical connector <NUM> are disposed or situated within the connecting portion <NUM> of the shell housing <NUM> to electrically and/or mechanically engage respective corresponding features of the adapter assembly <NUM>, as will be described in greater detail below.

The power handle <NUM> has an inner handle housing <NUM> including a proximal half section 111a and a distal half section 111b that are coupled together to house a power-pack core assembly <NUM> therein. The power-pack core assembly <NUM> is configured to control the various operations of the handle assembly <NUM> and thus, the surgical device <NUM>.

The distal half section 111b of the inner handle housing <NUM> is configured and adapted to support a control plate <NUM> of the power-pack core assembly <NUM> such that the control plate <NUM> abuts the plate assembly <NUM> of the shell housing <NUM> when the power handle <NUM> is disposed within the shell housing <NUM>. The distal half section 111b of the inner handle housing <NUM> also supports a plurality of actuator interfaces <NUM> that are in operative registration with the respective actuators <NUM> of the shell housing <NUM>.

As shown in <FIG> and <FIG>, the power-pack core assembly <NUM> includes a battery circuit <NUM>, a controller circuit board <NUM>, and a rechargeable battery <NUM> configured to supply power to any of the electrical components of the handle assembly <NUM>. The controller circuit board <NUM> includes a motor controller circuit board 142a, a main controller circuit board 142b, and a first ribbon cable 142c interconnecting the motor controller circuit board 142a and the main controller circuit board 142b. A display screen <NUM> is supported on the main controller circuit board 142b and visible through a clear or transparent window <NUM> provided in the proximal half-section 111a of the inner handle housing <NUM>. A USB connector <NUM> (or other data connector) is also supported on the main controller circuit board 142b and is accessible through the control plate <NUM> of the power-pack core assembly <NUM>.

The power-pack core assembly <NUM> further includes a first motor <NUM>, a second motor <NUM>, and a third motor <NUM> disposed between the motor controller circuit board 142a and the main controller circuit board 142b. Each of the first, second, and third motors <NUM>, <NUM>, <NUM> is electrically connected to the controller circuit board <NUM> and the battery <NUM>, and controlled by a respective motor controller disposed on the motor controller circuit board 142a which, in turn, is coupled to a respective main controller disposed on the main controller circuit board 142b.

Each of the first, second, and third motors <NUM>, <NUM>, <NUM> is supported on a motor bracket <NUM> such that respective motor shaft 152a, 154a, 156a extending from the first, second, and third motors <NUM>, <NUM>, <NUM> are rotatably disposed within respective apertures of the motor bracket <NUM>. The motor bracket <NUM> rotatably supports three rotatable drive connector sleeves 152b, 154b, 156b that are keyed to the respective motor shafts 152a, 154a, 156a of the first, second, and third motors <NUM>, <NUM>, <NUM>. The drive connector sleeves 152b, 154b, 156b non-rotatably receive proximal ends of the respective coupling shafts 124a, 124b, 124c of the plate assembly <NUM> of the shell housing <NUM>, when the power handle <NUM> is disposed within the shell housing <NUM>, and are each spring biased away from the respective motors <NUM>, <NUM>, <NUM>.

The motor bracket <NUM> also supports an electrical receptacle <NUM>. The electrical receptacle <NUM> is in electrical connection with the main controller circuit board 142b by a second ribbon cable 142d. The electrical receptacle <NUM> defines a plurality of electrical slots for receiving respective electrical contacts or blades extending from the pass-through connector <NUM> of the plate assembly <NUM> of the shell housing <NUM>.

Rotation of the motor shafts 152a, 154a, 156a by the respective first, second, and third motors <NUM>, <NUM>, <NUM> function to drive shafts and/or gear components of the adapter assembly <NUM> in order to perform the various operations of the handle assembly <NUM>, as will be described in greater detail below.

In use, when the adapter assembly <NUM> is mated to the handle assembly <NUM>, each of the coupling shafts 124a, 124b, 124c of the handle assembly <NUM> couples with a corresponding rotatable connector sleeve <NUM>, <NUM>, <NUM> (<FIG>) of the adapter assembly <NUM>. In this regard, the interface between corresponding coupling shafts 124a, 124b, 124c and connector sleeves <NUM>, <NUM>, <NUM> are keyed such that rotation of each of the coupling shafts 124a, 124b, 124c of the handle assembly <NUM> causes a corresponding rotation of the corresponding connector sleeve <NUM>, <NUM>, <NUM> of the adapter assembly <NUM>.

The coupling shafts 124a, 124b, 124c of handle assembly <NUM> are configured to be independently rotated by the respective motor <NUM>, <NUM>, <NUM> such that rotational force(s) are selectively transferred from the motors <NUM>, <NUM>, <NUM> of the handle assembly <NUM> to the adapter assembly <NUM>. The selective rotation of the coupling shaft(s) 124a, 124b, 124c of the handle assembly <NUM> allows the handle assembly <NUM> to selectively actuate different functions of the reload <NUM>.

Turning now to <FIG>, the adapter assembly <NUM> is configured to convert a rotation of the coupling shaft(s) 124a, 124b, 124c (<FIG>) of the handle assembly <NUM> into axial translation useful for effecting various functions of the surgical device <NUM> (<FIG>). The adapter assembly <NUM> includes an adapter or knob housing <NUM> and an outer tube <NUM> extending from a distal end of the knob housing <NUM>. The knob housing <NUM> and the outer tube <NUM> are configured and dimensioned to house and support the components of the adapter assembly <NUM>. The knob housing <NUM> includes a drive coupling assembly <NUM> which is configured and adapted to connect to the connecting portion <NUM> (<FIG>) of the shell housing <NUM> of the handle assembly <NUM>. The outer tube <NUM> includes a connector sleeve <NUM> fixedly supported at a distal end thereof. The connector sleeve <NUM> is configured to selectively secure the reload <NUM> (<FIG>) to the adapter assembly <NUM>.

As shown in <FIG> and <FIG>, the adapter assembly <NUM> includes a rotation assembly <NUM> configured to enable rotation of the adapter assembly <NUM> relative to the handle assembly <NUM>. Specifically, the knob housing <NUM> and the outer tube <NUM> of the adapter assembly <NUM> are rotatable relative to the drive coupling assembly <NUM> of the adapter assembly <NUM>. The rotation assembly <NUM> includes a lock button <NUM> operably supported on the knob housing <NUM> and configured for actuating the rotation assembly <NUM>. When rotation assembly <NUM> is in an unlocked configuration, the knob housing <NUM> and the outer tube <NUM> are rotatable along a longitudinal axis "X" of the adapter assembly <NUM> relative to the drive coupling assembly <NUM>. When rotation assembly <NUM> is in a locked configuration, the knob housing <NUM> and the outer tube <NUM> are rotationally secured relative to the drive coupling assembly <NUM>.

The adapter assembly <NUM> further includes an attachment/detachment button <NUM> supported on the drive coupling assembly <NUM> of the adapter assembly <NUM>. In use, when the adapter assembly <NUM> is connected to the shell housing <NUM> of the handle assembly <NUM>, the attachment/detachment button <NUM> secures and retains the adapter assembly <NUM> and the handle assembly <NUM> with one another. When the attachment/detachment button <NUM> is depressed or actuated, the adapter assembly <NUM> and the handle assembly <NUM> may be disconnected from each other.

The adapter assembly <NUM> further includes a cavity <NUM> defined within the drive coupling assembly <NUM> that is configured to receive a pin connector assembly <NUM> (<FIG>) of an electrical assembly <NUM> configured for establishing an electrical connection with and between the handle assembly <NUM>, the adapter assembly <NUM>, and the reload <NUM>, as described in further detail below. The cavity <NUM> may include guiding ribs <NUM> configured to receive a printed circuit board <NUM> of the pin connector assembly <NUM>.

As illustrated in <FIG>, the drive coupling assembly <NUM> of the adapter assembly <NUM> rotatably supports first, second, and third connector sleeves <NUM>, <NUM> and <NUM> therein, and an inner housing member <NUM> disposed within the knob housing <NUM> rotatably supports first, second, and third rotatable proximal drive shafts <NUM>, <NUM>, <NUM> therein. Each of the first, second, and third connector sleeves <NUM>, <NUM>, <NUM> is configured to mate with a respective coupling shaft 124a, 124c, 124b (<FIG>) of the handle assembly <NUM>. Each of the first, second, and third connector sleeves <NUM>, <NUM>, <NUM> is further configured to mate with a proximal end of the respective first, second, and third proximal drive shafts <NUM>, <NUM>, <NUM> of the adapter assembly <NUM> such that each of the first, second, and third proximal drive shafts <NUM>, <NUM>, <NUM> functions as a rotation receiving member to receive rotational forces from the respective coupling shafts 124a, 124c, 124b of the handle assembly <NUM>.

The adapter assembly <NUM> includes first, second and third force/rotation transmitting/converting assemblies <NUM>, <NUM>, <NUM> disposed within the inner housing member <NUM> and the outer tube <NUM>. Each of the force/rotation transmitting/converting assemblies <NUM>, <NUM>, <NUM> is configured and adapted to transmit or convert a rotation of the respective coupling shaft 124a, 124c, 124b of the handle assembly <NUM> into axial translation to effectuate operation of the reload <NUM> (<FIG>), as will be described in greater detail below.

As shown in <FIG> and <FIG>, the first force/rotation transmitting/converting assembly <NUM> includes the first rotatable proximal drive shaft <NUM>, as described above, a second rotatable proximal drive shaft <NUM>, a rotatable distal drive shaft <NUM>, and a coupling member <NUM>. First force/rotation transmitting/converting assembly <NUM>, as illustrated in <FIG>, further includes a trocar assembly <NUM> removably supported in a distal end of outer tube <NUM>. Trocar assembly <NUM> includes a tubular outer housing <NUM>, a trocar member <NUM> slidably disposed within tubular outer housing <NUM>, and a drive screw <NUM> operably received within trocar member <NUM> for axially moving trocar member <NUM> relative to tubular housing <NUM>. In particular, trocar member <NUM> includes a proximal end 274a having an inner threaded portion <NUM> which engages a threaded distal portion 276b of drive screw <NUM>. Trocar member <NUM> further includes at least one longitudinally extending flat 274d formed in an outer surface thereof which mates with a corresponding flat 272b formed in tubular housing <NUM> thereby inhibiting rotation of trocar member <NUM> relative to tubular housing <NUM> as drive screw <NUM> is rotated. A distal end 274b of trocar member <NUM> is configured to selectively engage anvil assembly <NUM> (<FIG>).

Tubular housing <NUM> of trocar assembly <NUM> is axially and rotationally fixed within outer tube <NUM> of adapter assembly <NUM>. Tubular housing <NUM> defines a pair of radially opposed, and radially oriented openings 272a which are configured and dimensioned to cooperate with a pair of lock pins 275c of a trocar assembly release mechanism <NUM> (see <FIG> and <FIG>) of adapter assembly <NUM>. With continued reference to <FIG>, adapter assembly <NUM> includes a support block <NUM> fixedly disposed within outer tube <NUM>. The pair of lock pins 275c extend through support block <NUM> and into tubular housing <NUM> of trocar assembly <NUM> to connect trocar assembly <NUM> to adapter assembly <NUM>.

As illustrated in <FIG>, trocar assembly release mechanism <NUM> includes a release button 275a pivotally supported on a hinge guide <NUM> and in outer tube <NUM>. Release button 275a is biased, via a spring 275d (see <FIG>, <FIG>), to a locked/extended condition. Trocar assembly release mechanism <NUM> further includes a spring clip 275b having a backspan connected to release button 275a, and a pair of legs, extending from the backspan, that extend through support block <NUM> and transversely across trocar assembly <NUM>. Each of the pair of legs of spring clip 275b extends through a respective lock pin 275c which is slidably disposed within a respective radial opening 272a of tubular housing <NUM> and radial opening 292a of support block <NUM>. Each of the pair of legs of spring clip 275b defines a gooseneck along a length thereof such that a distal portion of each of the pair of legs of spring clip 275b is closer to one another as compared to a proximal portion of each of the pair of legs of spring clip 275b.

In use, when release button 275a is depressed (e.g., in a radially inward direction, <FIG>), release button 275a moves spring clip 275b transversely relative to trocar assembly <NUM>. As spring clip 275b is moved transversely relative to trocar assembly <NUM>, the pair of legs of spring clip 275b translate through the pair of lock pins 275c such that a gooseneck in each leg acts to cam and urge the pair of lock pins 275c radially outward. Specifically, the pair of lock pins 275c are traversed by the gooseneck portions the pair of legs of spring clip 275b, transitioning from the distal portions thereof to the proximal portions thereof. In so moving, each of the pair of lock pins 275c is urged radially outward by a distance sufficient that each of the pair of lock pins 275c clears respective opening 272a of tubular housing <NUM>, and in an embodiment, project from outer tube <NUM> or are flush with an outer surface of outer tube <NUM>. It is contemplated that outer tube <NUM> may include openings 206a (see <FIG>) formed therein which are in registration with each of the pair of lock pins 275c. With the pair of lock pins 275c free and clear of tubular housing <NUM>, trocar assembly <NUM> may be axially withdrawn from within the distal end of outer tube <NUM> of adapter assembly <NUM>, or may be inserted into the distal end of outer tube <NUM> of adapter assembly <NUM>.

Projection of the pair of lock pins 275c, radially outward from outer tube <NUM> (or to be substantially flush with an outer surface of the outer tube <NUM>), provides a visual indication to the end user that no trocar assembly <NUM> is inserted into the distal end of outer tube <NUM> of adapter assembly <NUM>, or that trocar assembly <NUM> is not properly inserted into the distal end of outer tube <NUM> of adapter assembly <NUM>. When trocar assembly <NUM> is properly inserted into the distal end of outer tube <NUM> of adapter assembly <NUM>, the pair of lock pins 275c of trocar assembly release mechanism <NUM> are in registration with, and enter into, a respective opening 272a of tubular housing <NUM> of trocar assembly <NUM> (see <FIG>), to thereby lock trocar assembly <NUM> within the distal end of outer tube <NUM> of adapter assembly <NUM>, and to thereby provide a visual indication to the end user that trocar assembly <NUM> is properly inserted into the distal end of outer tube <NUM> of adapter assembly <NUM>.

Turning now to <FIG>, disclosing an embodiment according to the invention, adapter assembly <NUM> includes a trocar assembly release mechanism <NUM>. As illustrated, trocar assembly release mechanism <NUM> includes a pair of release buttons 1275a rotatably supported on a support block (not shown) and in outer tube <NUM>, via a respective pivot pin 1275e. Each release button 1275a is biased, via a respective biasing member 1275d (e.g., leaf spring), to a locked condition.

Each release button 1275a is identical to one another, and thus, only one of the pair of release buttons 1275a will be described in detail herein. Release button 1275a is substantially semi-circular, extending approximately <NUM>° about pivot pin 1275e. Release button 1275a defines a distal face or surface 1275a' against which a portion of biasing member 1275d engages to urge release button 1275a proximally, and a proximal face or surface projecting to a tail 1275a". An outer surface of release button 1275a may include finger gripping features (e.g., ribs, knurling, etc.) formed thereon.

Release button 1275a is movable between a first unlocked position and a second locked position. If or when a trocar assembly <NUM> is not properly inserted into the distal end of outer tube <NUM> of adapter assembly <NUM>, the release button 1275a is rotated or urged radially outward from outer tube <NUM> by trocar assembly <NUM>, to the first unlocked position, thereby providing a visual indication to the end user that trocar assembly <NUM> is not properly inserted into the distal end of outer tube <NUM> of adapter assembly <NUM>. When a trocar assembly <NUM> is properly inserted into the distal end of outer tube <NUM> of adapter assembly <NUM>, the release button 1275a is rotated or urged radially inward, to the second locked position, by biasing member 1275d rotating release button 1275a such that tail 1275a" thereof is received in a recess or depression formed in the outer surface of tubular housing <NUM> of trocar assembly <NUM> (e.g., similar to openings 272a of tubular housing <NUM>). When release button 1275a is in the second locked position, a visual indication is provided to the end user that trocar assembly <NUM> is properly inserted and locked into the distal end of outer tube <NUM> of adapter assembly <NUM>.

In an embodiment, with reference to <FIG>, tail 1275a" includes a chamfered distal surface to facilitate receipt or passage of trocar assembly <NUM> during connection of trocar assembly <NUM> to outer tube <NUM>, when release button 1275a is in the second locked position. Tail 1275a" further includes a substantially squared proximal surface to inhibit withdrawal or disconnection of trocar assembly <NUM> from outer tube <NUM> when release button 1275a is in the second locked position relative to tubular housing <NUM> of trocar assembly <NUM>.

With reference to <FIG>, in operation, the first force/rotation transmitting/converting assembly <NUM> functions to advance/retract trocar member <NUM> of trocar assembly <NUM> of the adapter assembly <NUM>, and to open/close the reload <NUM> (<FIG>) when an anvil assembly <NUM> is connected to the trocar member <NUM>. Specifically, as the first rotatable proximal drive shaft <NUM> is rotated, due to a rotation of the first connector sleeve <NUM>, as a result of the rotation of the first coupling shaft 124a (<FIG>) of the handle assembly <NUM>, the second rotatable proximal drive shaft <NUM> is caused to be rotated. Rotation of the second rotatable proximal drive shaft <NUM> results in contemporaneous rotation of the rotatable distal drive shaft <NUM>. Rotation of the rotatable distal drive shaft <NUM> causes contemporaneous rotation of the coupling member <NUM>, which, in turn, causes contemporaneous rotation of the drive screw <NUM> of the trocar assembly <NUM>. As the drive screw <NUM> is rotated within and relative to the trocar member <NUM>, engagement between the trocar member <NUM> and the drive screw <NUM> (e.g., threaded engagement) causes axial translation of the trocar member <NUM> within the tubular housing <NUM> of the trocar assembly <NUM>. Specifically, rotation of the drive screw <NUM> in a first direction causes axial translation of the trocar member <NUM> in a first direction (e.g., extension or advancement of the trocar assembly <NUM>), and rotation of the drive screw <NUM> in a second direction causes axial translation of the trocar member <NUM> in a second direction (e.g., retraction of the trocar assembly <NUM>). When the anvil assembly <NUM> is connected to the trocar member <NUM>, the axial translation of the trocar member <NUM> in the first direction results in an opening of the reload <NUM>, and the axial translation of the trocar member <NUM> in the second direction results in a closing of the reload <NUM>.

As shown in <FIG> and <FIG>, the second force/rotation transmitting/converting assembly <NUM> of adapter assembly <NUM> includes the second proximal drive shaft <NUM>, as described above, a first coupling shaft <NUM>, a planetary gear set <NUM>, a staple lead screw <NUM>, and a staple driver <NUM>. The second force/rotation transmitting/converting assembly <NUM> of the adapter assembly <NUM> also includes an outer flexible band assembly <NUM> secured to the staple driver <NUM>. The outer flexible band assembly <NUM> includes first and second flexible bands 255a, 255b laterally spaced and connected at proximal ends thereof to a support ring 255c and at distal ends thereof to a proximal end of a support base 255d. The outer flexible band assembly <NUM> further includes first and second connection extensions 255e, 255f extending proximally from the support ring 255c that are configured to operably connect the outer flexible band assembly <NUM> to the staple driver <NUM>. The second force/rotation transmitting/converting assembly <NUM> functions to fire staples "S" (<FIG>) of the reload <NUM> for formation against the anvil assembly <NUM>.

In operation, as the second rotatable proximal drive shaft <NUM> is rotated due to a rotation of the second connector sleeve <NUM>, as a result of the rotation of the second coupling shaft 124c (<FIG>) of the handle assembly <NUM>, the first coupling shaft <NUM> is caused to be rotated, which in turn causes the planetary gear set <NUM> to rotate. Rotation of the planetary gear set <NUM> causes contemporaneous rotation of the staple lead screw <NUM>. As the staple lead screw <NUM> is rotated, the staple driver <NUM> is caused to be axially translated, which in turn causes the outer flexible band assembly <NUM> to be axially translated. As the outer flexible band assembly <NUM> is axially translated, the support base 255d presses against a driver adapter of a staple driver assembly (not shown) of the reload <NUM> to distally advance a driver and fire staples from a staple cartridge (not shown) of the reload <NUM> and against anvil assembly <NUM> for formation of the staples in underlying tissue.

With reference to <FIG> and <FIG>, the third force/rotation transmitting/converting assembly <NUM> of the adapter assembly <NUM> includes the third proximal drive shaft <NUM>, as described above, a second coupling shaft <NUM>, a hollow shaft <NUM>, a planetary gear set <NUM>, a knife lead screw <NUM>, and a knife driver <NUM>. The third force/rotation transmitting/converting assembly <NUM> of adapter assembly <NUM> also includes an inner flexible band assembly <NUM> secured to the knife driver <NUM>. The inner flexible band assembly <NUM> includes first and second flexible bands 265a, 265b laterally spaced and connected at proximal ends thereof to a support ring 265c and at distal ends thereof to a proximal end of a support base 265d. The third force/rotation transmitting/converting assembly <NUM> functions to fire an annular knife <NUM> (<FIG>) of the reload <NUM>.

In operation, as the third rotatable proximal drive shaft <NUM> is rotated due to a rotation of the third connector sleeve <NUM>, as a result of the rotation of the third coupling shaft 124b (<FIG>) of the handle assembly <NUM>, the second coupling shaft <NUM> is caused to be rotated, which in turn causes the hollow shaft <NUM> to rotate. Rotation of the hollow shaft <NUM> results in contemporaneous rotation of the planetary gear set <NUM>, which in turn causes the knife lead screw <NUM> to rotate. As the knife lead screw <NUM> is rotated, the knife driver <NUM> is caused to be axially translated, which in turn causes the inner flexible band assembly <NUM> to be axially translated. As the inner flexible band assembly <NUM> is axially translated, the support base 265d presses against a knife carrier (not shown) of the reload <NUM> to distally advance the knife carrier and fire the an annular knife (not shown) of the reload <NUM> against the anvil assembly <NUM> for cutting of tissue clamped in the reload <NUM>.

Claim 1:
An adapter assembly (<NUM>) for connecting a surgical stapler to an electromechanical handle assembly (<NUM>), the adapter assembly comprising:
an outer tube (<NUM>);
a trocar assembly (<NUM>) releasably securable within a distal end of the outer tube, the trocar assembly including a tubular trocar housing (<NUM>) defining a pair of openings or recesses in the outer surface therein (272a), wherein the pair of openings or recesses are in opposed radially extending relation to one another; and
a trocar assembly release mechanism (<NUM>) configured to releasably secure the trocar assembly within the outer tube, the release mechanism including:
a pair of release buttons (1275a) rotatably supported on opposed radial sides of the outer tube (<NUM>), wherein each release button is selectively receivable within a respective opening of the pair of openings or recesses formed in the trocar housing, each release button being movable between a release condition and an engaged condition; and
a pair of biasing members (1275d) supported in the outer tube and associated with a respective one of the pair of release buttons, wherein the biasing members urge the pair of release buttons to the engaged condition and into engagement with the trocar housing;
wherein, when the release buttons are in the engaged, locked condition, the release buttons are disposed within the pair of openings or recesses of the trocar housing to maintain the trocar assembly connected to the outer tube; and
wherein, when the release buttons are in the release depressed, unlocked condition, the release buttons are disengaged from the pair of openings or recesses of the trocar housing to release the trocar assembly from the outer tube;
each release button defines a proximal face projecting to a tail (1275a"), wherein when the trocar assembly is properly inserted into the outer tube, the release buttons are urged radially inward, to the locked condition, by the biasing members (<NUM>) rotating the release buttons such that the tails thereof are received in the openings or recesses in the trocar housing to provide a visual indication to an end user that the trocar assembly is properly inserted into the outer tube and wherein when the trocar assembly is not properly inserted into the outer tube, the release buttons are urged radially outward, to the unlocked condition, to provide a visual indication to an end user that the trocar assembly is not properly inserted into the outer tube.