Patent Description:
The present disclosure relates generally to surgical instruments for endoscopic use and, more specifically, to surgical instruments including adapter assemblies that articulate an attached surgical loading unit.

Various types of surgical instruments used to endoscopically treat tissue are known in the art, and are commonly used, for example, for closure of tissue or organs in transection, resection, anastomoses, for occlusion of organs in thoracic and abdominal procedures, and for electro surgically fusing or sealing tissue.

One example of such a surgical instrument is a surgical stapling instrument. Typically, surgical stapling instruments include an end effector having an anvil assembly and a cartridge assembly for supporting an array of surgical staples, an approximation mechanism for approximating the cartridge and anvil assemblies, a rotation assembly for rotating the cartridge and anvil assemblies about an axis, and a firing mechanism for ejecting the surgical staples from the cartridge assembly.

During laparoscopic or endoscopic surgical procedures, access to a surgical site is achieved through a small incision or through a narrow cannula inserted through a small entrance wound in a patient. Because of limited area available to access the surgical site, many endoscopic instruments include mechanisms for articulating the end effector of the instrument in relation to a body portion of the instrument to improve access to tissue to be treated. Some instruments include a motor or drive element for causing articulation of the end effector, and also include a rotation assembly for causing rotation of the end effector.

<CIT>relates to a surgical instrument that includes an end effector, an articulation joint, an articulation member and a position sensor configured to detect a position of the articulation member.

It would be beneficial to provide an improved surgical instrument or adapter assembly which can detect and/or correct any undesired partial articulation of the end effector.

The present disclosure relates to an adapter assembly configured to mechanically engage a surgical instrument. The adapter assembly includes a knob housing, an outer tube, an end effector, an articulation link, and a sensor assembly. The outer tube extends distally from the knob housing and defines a longitudinal axis. The end effector extends distally from the outer tube, and is movable from a first position where the end effector is aligned with the longitudinal axis, to a second position where the end effector is disposed at an angle relative to the longitudinal axis. The articulation link extends through at least a portion of the outer tube and is disposed in mechanical cooperation with the end effector. Longitudinal translation of the articulation link relative to the outer tube causes the end effector to move from its first position to its second position. The sensor assembly includes a first portion disposed in mechanical cooperation with the articulation link, and a second portion disposed at least partially within the outer tube. The sensor assembly is configured to determine an actual amount of articulation of the end effector based on a distance the articulation link moves longitudinally relative to the outer tube.

In disclosed embodiments, the sensor assembly is configured to communicate with software that compares the actual amount of articulation of the end effector with a desired amount of articulation of the end effector. It is disclosed that the software is disposed on a printed circuit board disposed at least partially within the knob housing.

It is also disclosed that one of the first portion or the second portion of the sensor assembly is a magnet, and the other of the first portion or the second portion of the sensor assembly is a magnetoresistive sensor.

It is further disclosed that one of the first portion or the second portion of the sensor assembly is a leaf spring, and the other of the first portion or the second portion of the sensor assembly is a thin-pot resistive sensor.

Additionally, it is disclosed that the adapter assembly includes a second sensor assembly disposed at least partially within the knob housing. The second sensor assembly is configured to detect manual rotation of the knob housing relative to the outer tube. In embodiments, the second sensor assembly includes at least one sensor and at least one magnet, and the at least one sensor of the second sensor assembly includes at least two Hall effect sensors. It is also disclosed that the at least one magnet of the second sensor assembly includes a refrigerator-type magnet. In further embodiments, the software is disposed on a printed circuit board disposed at least partially within the knob housing, and the at least two Hall effect sensors are disposed on the printed circuit board.

The present disclosure also relates to a surgical instrument including a handle assembly and an adapter assembly. The handle assembly includes a first drive member. The adapter assembly is configured to selectively engage the handle assembly and includes a knob housing, an outer tube, an end effector, an articulation link, a ring gear, and a sensor assembly. The outer tube extends distally from the knob housing and defines a longitudinal axis. The end effector extends distally from the outer tube, and is movable from a first position where the end effector is aligned with the longitudinal axis, to a second position where the end effector is disposed at an angle relative to the longitudinal axis. The articulation link extends through at least a portion of the outer tube and is disposed in mechanical cooperation with the end effector. Longitudinal translation of the articulation link relative to the outer tube causes the end effector to move from its first position to its second position. The ring gear is disposed at least partially within the knob housing and is in mechanical cooperation with the first drive member when the adapter assembly is engaged with the handle assembly. Rotation of the first drive member causes rotation of the ring gear about the longitudinal axis, which causes longitudinal translation of the articulation link. The sensor assembly includes a first portion disposed in mechanical cooperation with the articulation link, and a second portion disposed at least partially within the outer tube. The sensor assembly is configured to determine an actual amount of articulation of the end effector based on a distance the articulation link moves longitudinally relative to the outer tube.

In disclosed embodiments, manual rotation of the knob housing causes undesired articulation of the end effector. In embodiments, the sensor assembly is configured to communicate with software, and the software compares the actual amount of articulation of the end effector with a desired amount of articulation of the end effector. It is further disclosed that the software is configured to instruct the first drive member of the surgical instrument to move the articulation link such that the actual articulation of the end effector equals the desired articulation of the end effector.

It is also disclosed that the surgical instrument includes a second sensor assembly disposed at least partially within the knob housing. The second sensor assembly is configured to detect manual rotation of the knob housing relative to the outer tube. In embodiments, the second sensor assembly includes at least one sensor and at least one magnet. It is further disclosed that the at least one sensor of the second sensor assembly includes at least two Hall effect sensors, and that the at least one magnet of the second sensor assembly includes a refrigerator-type magnet (e.g., a magnet having appropriately alternating north/south oriented poles).

In disclosed embodiments, one of the first portion or the second portion of the sensor assembly is a magnet, and the other of the first portion or the second portion of the sensor assembly is a magnetoresistive sensor.

In additional embodiments, one of the first portion or the second portion of the sensor assembly is a leaf spring, and the other of the first portion or the second portion of the sensor assembly is a thin-pot resistive senor.

Surgical instruments including embodiments of the presently disclosed adapter assemblies are disclosed herein with reference to the drawings, wherein:.

Persons skilled in the art will understand that the adapter assemblies and surgical loading units specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.

As used herein, the term "distal" refers to that portion of the surgical instrument which is farthest from a clinician, while the term "proximal" refers to that portion of the surgical instrument which is closest to the clinician. In addition, as used herein, the term clinician refers to medical staff including doctors, nurses and support personnel.

The present disclosure is directed to a surgical instrument including an adapter assembly configured to be actuated by a hand-held actuator or a surgical robotic system, and a surgical loading unit coupled to the adapter assembly. The adapter assembly includes an articulation mechanism that drives an articulation of the surgical loading unit relative to the adapter assembly. The articulation mechanism includes a cam housing that defines a pair of cam slots, each of which receiving a corresponding pin of a pair of elongate shafts. As the cam housing rotates, the cam slots drive an opposing longitudinal motion of the pair of elongate shafts, which articulate the surgical loading unit. Additional advantages of the presently disclosed surgical instruments and components thereof are described below.

<FIG> illustrate a surgical instrument <NUM> including a handle assembly <NUM>, an adapter assembly <NUM> configured to be coupled to the handle assembly <NUM>, and a surgical loading unit <NUM> pivotably coupled to the adapter assembly <NUM>. While the depicted surgical instrument <NUM> may be configured to fire staples, it is contemplated that the surgical instrument <NUM> may be adapted to fire any other suitable fastener such as clips and two-part fasteners. Additionally, while the figures depict a linear surgical stapling instrument <NUM>, it is envisioned that certain components described herein may be adapted for use in other types of endoscopic surgical instruments including non-linear surgical stapler loading units, endoscopic forceps, graspers, dissectors, other types of surgical stapling instruments, powered vessel sealing and/or cutting devices, etc..

Generally, the adapter assembly <NUM> of the surgical instrument <NUM> includes an outer housing <NUM> and an outer tube <NUM> extending distally from the outer housing <NUM>. The outer housing <NUM> includes a knob housing <NUM> and a coupling mechanism <NUM> extending proximally from the knob housing <NUM> and configured to be operably coupled to the handle assembly <NUM> or a surgical robotic system (not shown) responsible for actuating the surgical instrument <NUM>. The outer tube <NUM> has a proximal end portion fixed within the distal end portion of the knob housing <NUM>. In other embodiments, the outer tube <NUM> may be rotatable relative to and within the knob housing <NUM>. The surgical loading unit <NUM> is adapted to be attached to a distal end portion of the outer tube <NUM> of the adapter assembly <NUM> and may be configured for a single use, or may be configured to be used more than once.

The surgical loading unit <NUM> includes a collar <NUM> pivotably coupled to the distal end portion of the outer tube <NUM> and an end effector <NUM> supported on the collar <NUM>. The end effector <NUM> includes an anvil plate <NUM> non-rotationally coupled to the collar <NUM>, and a staple cartridge assembly <NUM> disposed in opposed relation with the anvil plate <NUM>. The staple cartridge assembly <NUM> has a chassis <NUM> pivotably coupled to the collar <NUM> and a staple cartridge body <NUM> configured for removable receipt in a channel <NUM> of the chassis <NUM>.

For a detailed description of the handle assembly <NUM>, reference may be made to <CIT>, and <CIT>.

With reference to <FIG>, the articulation mechanism of the adapter assembly <NUM> will now be described. The adapter assembly <NUM> includes an articulation input shaft <NUM>, a firing input shaft <NUM>, and a rotation input shaft <NUM> each rotationally supported in the coupling mechanism <NUM> of the outer housing <NUM> (<FIG>). The articulation input shaft <NUM> has a proximal end portion 50a configured to be drivingly coupled to a corresponding drive member 13a of the handle assembly <NUM> to effect a rotation of the articulation input shaft <NUM>. The articulation input shaft <NUM> has a distal end portion 50b having a gear <NUM> (e.g., a spur gear) fixed thereabout.

The adapter assembly <NUM> includes a ring gear <NUM> operably coupled to the articulation input shaft <NUM> and non-rotationally coupled to a cam housing <NUM>. The ring gear <NUM> has an inner surface defining gear teeth <NUM> interfacing with gear teeth of a first gear 64a of a spur gear cluster <NUM>. The spur gear cluster <NUM> has a second gear 64b fixed to and disposed adjacent the first gear 64a and having a larger diameter than the first gear 64a. The second gear 64b of the spur gear cluster <NUM> interfaces with the gear <NUM> non-rotationally fixed about the distal end portion 50b of the articulation input shaft <NUM>. As such, a rotation of the articulation input shaft <NUM> rotates the first gear 64a and second gear 64b of the spur gear cluster <NUM>, which, in turn, drives a rotation of the ring gear <NUM>.

With reference to <FIG>, the cam housing <NUM> of the adapter assembly <NUM> is rotationally supported in the knob housing <NUM>. The cam housing <NUM> includes an annular plate or disc <NUM> and a tubular shaft <NUM> extending distally from the annular plate <NUM>. The annular plate <NUM> may be disposed within, and pinned to, the ring gear <NUM>, such that the cam housing <NUM> rotates with a rotation of the ring gear <NUM>. The tubular shaft <NUM> of the cam housing <NUM> defines a longitudinally-extending channel <NUM> therethrough. The channel <NUM> is dimensioned for receipt of various components of the articulation and firing mechanisms of the adapter assembly <NUM>, thereby allowing for a more compact design of the adapter assembly <NUM>.

With reference to <FIG>, the tubular shaft <NUM> of the cam housing <NUM> defines a proximal cam slot 72a in communication with the channel <NUM>, and a distal cam slot 72b located distally of the proximal cam slot 72a and in communication with the channel <NUM>. The proximal and distal cam slots 72a, 72b are longitudinally spaced from one another and wrap around a central longitudinal axis "X" (<FIG>) defined by the channel <NUM> of the tubular shaft <NUM> of the cam housing <NUM>. The proximal and distal cam slots 72a, 72b each have opposite helical configurations. For example, the proximal cam slot 72a may have a left-handed helical configuration, whereas the distal cam slot 72b may have a right-handed helical configuration, the importance of which being described in detail below. The cam slots 72a, 72b are layed out at a particular pitch such that a set rotation of the tubular shaft <NUM> results in a defined articulation for the three-bar linkage arrangement.

With reference to <FIG>, the adapter assembly <NUM> further includes a pair of first and second axially movable elongate shafts <NUM>, <NUM> and a pair of first and second articulation links <NUM>, <NUM>. The first and second elongate shafts <NUM>, <NUM> are disposed on opposite sides of the central longitudinal axis "X" of the cam housing <NUM>. Each of the first and second elongate shafts <NUM>, <NUM> has a proximal end portion 74a, 76a disposed within the knob housing <NUM>, and a distal end portion 74b, 76b disposed within the outer tube <NUM>.

The proximal end portion 74a of the first elongate shaft <NUM> has a radially-outwardly extending projection or pin <NUM> received within the proximal cam slot 72a. The proximal end portion 76a of the second elongate shaft <NUM> has a radially-outwardly extending projection or pin <NUM> received in the distal cam slot 72b. Due to the proximal and distal cam slots 72a, 72b of the cam housing <NUM> having opposing helical configurations (e.g., right-handed vs. left-handed threading), rotation of the cam housing <NUM> drives the first and second elongate shafts <NUM>, <NUM> in opposing longitudinal directions.

The first articulation link <NUM> of the surgical instrument <NUM> has a proximal end portion 86a pivotably coupled to the distal end portion 74b of the first elongate shaft <NUM>, and the second articulation link <NUM> has a proximal end portion 88a pivotably coupled to the distal end portion 76b of the second elongate shaft <NUM>. The first and second links <NUM>, <NUM> each have a distal end portion 86b, 88b pivotably coupled to opposite sides of the collar <NUM> of the surgical loading unit <NUM>. As such, the opposing longitudinal motion of the first and second elongate shafts <NUM>, <NUM>, induced by a rotation of the cam housing <NUM>, pushes and pulls the corresponding first and second links <NUM>, <NUM> to articulate the surgical loading unit <NUM> relative to the adapter assembly <NUM>.

With specific reference to <FIG>, the first articulation link <NUM> includes an inner-facing surface <NUM> and the second articulation link <NUM> includes an inner-facing surface <NUM> that faces the inner-facing surface <NUM> of the first link <NUM>. The inner-facing surface <NUM> of the first link <NUM> has a concave intermediate portion 90c disposed between a convex proximal end portion 90a of the inner-facing surface <NUM> and a convex distal end portion 90b of the inner-facing surface <NUM>. Similarly, the inner-facing surface <NUM> of the second link <NUM> has a concave intermediate portion 92c disposed between a convex proximal end portion 92a of the inner-facing surface <NUM> and a convex distal end portion 92b of the inner-facing surface <NUM>. The inner-facing surfaces <NUM>, <NUM> of the first and second links <NUM>, <NUM> are configured to guide and support blow-out plates 102a, 102b and a knife shaft <NUM> of an I-beam assembly <NUM> of the adapter assembly <NUM> during articulation of the surgical loading unit <NUM>.

In particular, the concave intermediate portion 90c of the inner-facing surface <NUM> of the first link <NUM> is dimensioned to receive a first blow-out plate 102a of the I-beam assembly <NUM> during articulation of the surgical loading unit <NUM> in a first direction, indicated by arrow "A" in <FIG>, whereas the concave intermediate portion 92c of the inner-facing surface <NUM> of the second link <NUM> is dimensioned to receive a second blow-out plate 102b of the I-beam assembly <NUM> during articulation of the surgical loading unit <NUM> in a second direction, indicated by arrow "B" in <FIG>.

The convex distal end portions 90b, 92b of the inner-facing surfaces <NUM>, <NUM> of the first and second links <NUM>, <NUM> further support the blow-out plates 102a, 102b and the knife shaft <NUM> of the I-beam assembly <NUM> during articulation of the surgical loading unit <NUM>. In this way, the inner-facing surfaces <NUM>, <NUM> of the respective first and second links <NUM>, <NUM> accommodate the flexing of the knife shaft <NUM> and blow-out plates 102a, 102b as the surgical loading unit <NUM> articulates to resist wear and tear of the knife shaft <NUM> and the blow-out plates 102a, 102b. For example, as best shown in <FIG>, articulation of the surgical loading unit <NUM> in the first direction causes the knife shaft <NUM> and the blow-out plates 102a, 102b to assume a curved shape, whereby the outer blow-out plate (e.g., the first blow-out plate 102a) is guided and supported by the concave intermediate portion 90c of the inner-facing surface <NUM> of the first link <NUM>, and the inner blow-out plate (e.g., the second blow-out plate 102b) is guided and supported by the convex distal end portion 92b of the inner-facing surface <NUM> of the second link <NUM>. As can be appreciated, during articulation of the surgical loading unit <NUM> in the second direction, the first and second links <NUM>, <NUM> work together in a similar manner to accommodate a flexing of the blow-out plates 102a, 102b and the knife shaft <NUM>.

In operation, to articulate the surgical loading unit <NUM>, the articulation input shaft <NUM> is rotated via an actuation of the handle assembly <NUM>. The articulation input shaft <NUM> transfers rotational motion from the gear <NUM> fixed thereabout to the ring gear <NUM> via the spur gear cluster <NUM>. Since the cam housing <NUM> is fixed to the ring gear <NUM>, the cam housing <NUM> rotates with the ring gear <NUM> about the central longitudinal axis "X. " As the cam housing <NUM> rotates, the proximal cam slot 72a of the cam housing <NUM> drives the pin <NUM> of the first elongate shaft <NUM> through the proximal cam slot <NUM> in a distal direction, indicated by arrow "C" in <FIG>, and the distal cam slot 72b of the cam housing <NUM> drives the pin <NUM> of the second elongate shaft <NUM> through the distal cam slot 72b in a proximal direction, indicated by arrow "D" in <FIG>.

Due to the first articulation link <NUM> acting as a pivotable coupling between the first elongate shaft <NUM> of the adapter assembly <NUM> and the first side of the surgical loading unit <NUM>, and the second link <NUM> acting as a pivotable coupling between the second elongate shaft <NUM> of the adapter assembly <NUM> and the second side of the surgical loading unit <NUM>, distal movement of the first elongate shaft <NUM> and proximal movement of the second elongate shaft <NUM> drives an articulation of the surgical loading unit <NUM> in the first direction indicated by arrow "A" in <FIG>. Similarly, proximal movement of the first elongate shaft <NUM> and distal movement of the second elongate shaft <NUM> drives an articulation of the surgical loading unit <NUM> in the second direction indicated by arrow "B" in <FIG>.

With reference to <FIG>, the firing and clamping mechanism of the adapter assembly <NUM> will now be described. The firing input shaft <NUM> of the adapter assembly <NUM> is centrally located between the articulation and rotation input shafts <NUM>, <NUM> and is configured to effect a clamping and stapling function of the surgical loading unit <NUM>. The firing input shaft <NUM> has a proximal end portion 52a configured to be drivingly coupled to the drive member 13b of the handle assembly <NUM> to drive a rotation of the firing input shaft <NUM>. It is contemplated that the firing input shaft <NUM> may be configured as a drive screw having a threaded outer surface <NUM>.

The adapter assembly <NUM> further includes an I-beam assembly <NUM>, briefly described above, having a nut <NUM>, a firing rod or tube <NUM>, and a knife shaft <NUM>. The nut <NUM> of the I-beam assembly <NUM> is disposed within the tubular shaft <NUM> of the cam housing <NUM> and is keyed to an inner tube <NUM>, such that rotation of the nut <NUM> within the inner tube <NUM> is prevented during rotation of the firing input shaft <NUM>. The nut <NUM> being disposed within the cam housing <NUM> of the articulation mechanism gives the adapter assembly <NUM> a compact design.

The firing rod <NUM> of the I-beam assembly <NUM> has a proximal end portion 110a fixed to the nut <NUM>, and a distal end portion 110b fixed to a proximal end portion 104a of the knife shaft <NUM> of the I-beam assembly <NUM>. In embodiments, the nut <NUM> may be directly attached to the proximal end portion 104a of the knife shaft <NUM> rather than be coupled via the firing rod <NUM>. Since the knife shaft <NUM> of the I-beam assembly <NUM> is fixed to the nut <NUM>, axial movement of the nut <NUM> through the outer tube <NUM>, in response to a rotation of the firing input shaft <NUM>, drives an axial movement of the knife shaft <NUM>.

With reference to <FIG>, <FIG>, the knife shaft <NUM> of the I-beam assembly includes a plurality of stacked elongated, rectangular blades <NUM>. The plurality of blades <NUM> have an upper portion 114a extending through a longitudinally-extending slot <NUM> defined in the anvil plate <NUM>, and a lower portion 114b extending through a longitudinally-extending slot <NUM> defined in the chassis <NUM> of the staple cartridge assembly <NUM>. As shown in <FIG>, the upper portion 114a of the blades <NUM> overlap with the anvil plate <NUM>, and the lower portion 114b of the blades <NUM> overlap with the chassis <NUM>. It is contemplated that this overlapping arrangement prevents buckling of the knife shaft <NUM> during firing.

The knife shaft <NUM> of the I-beam assembly <NUM> has a distal end portion 104b disposed within the surgical loading unit <NUM>. The distal end portion 104b of the knife shaft <NUM> is configured to pivot the staple cartridge assembly <NUM> toward the anvil plate <NUM> during distal advancement of the knife shaft <NUM>. The distal end portion 104b of the knife shaft <NUM> has an upper foot <NUM> disposed within a channel <NUM> defined by the anvil plate <NUM>, a lower foot <NUM> disposed outside of the chassis <NUM> of the staple cartridge assembly <NUM>, and a sharp distally-oriented surface <NUM> extending between the upper and lower foots <NUM>, <NUM>. The distally-oriented surface <NUM> is configured to sever tissue during distal advancement thereof through the end effector <NUM>.

In operation, to fire and clamp the surgical loading unit <NUM>, the firing input shaft <NUM> is rotated via an actuation of the handle assembly <NUM> attached to the coupling mechanism <NUM> of the adapter assembly <NUM>. The firing input shaft <NUM> drives a translation of the nut <NUM> in a distal direction, indicated by arrow "C" in <FIG>, relative to the firing input shaft <NUM>. Given that the I-beam assembly <NUM>, including the nut <NUM>, the firing rod <NUM>, and the knife shaft <NUM>, is one integral unit, the firing rod <NUM> and the knife shaft <NUM> advance distally with the nut <NUM>. The distal end portion 104b of the knife shaft <NUM> of the I-beam assembly <NUM> advances distally through the anvil plate <NUM> and the chassis <NUM> to pivot the chassis <NUM> toward the anvil plate <NUM>. As the distal end portion 104b of the knife shaft <NUM> advances distally through the anvil plate <NUM> and the chassis <NUM>, any tissue disposed therebetween is severed by the sharp, distally-oriented surface <NUM> of the knife shaft <NUM>.

With reference to <FIG>, the rotation mechanism of the adapter assembly <NUM> will now be described. The rotation input shaft <NUM> of the adapter assembly <NUM> has a proximal end portion 54a configured to be drivingly coupled to a drive member 13c of the handle assembly <NUM> to drive a rotation of the rotation input shaft <NUM>. The rotation input shaft <NUM> has a gear <NUM> fixed about a distal end portion 54b thereof. The gear <NUM> of the rotation input shaft <NUM> is operably coupled to teeth <NUM> of a rotation ring gear <NUM> via an idler gear <NUM>. In embodiments, the gear <NUM> of the rotation input shaft <NUM> may directly interface with the rotation ring gear <NUM>.

The rotation ring gear <NUM> has a pair of tabs 134a, 134b extending radially outward from opposite radial positions of the rotation ring gear <NUM>. The tabs 134a, 134b of the rotation ring gear <NUM> interlock with corresponding recesses (not explicitly shown) defined in an inner surface of the knob housing <NUM>, such that the knob housing <NUM> is rotatable with the rotation ring gear <NUM> relative to the coupling mechanism <NUM>. In embodiments, the rotation ring gear <NUM> may have any suitable feature that fastens the rotation ring gear <NUM> to the knob housing <NUM>, such as, for example, threaded engagement, frictional engagement, lock and key engagement, latches, buttons, bayonet-type connections, welding, adhesives and/or other mechanisms.

In operation, to rotate the surgical loading unit <NUM>, the rotation input shaft <NUM> is rotated via an actuation of the handle assembly <NUM> attached to the coupling mechanism <NUM> of the adapter assembly <NUM>. Rotational motion of the rotation input shaft <NUM> is transferred to the rotation ring gear <NUM> via the idler gear <NUM>. Since the tabs 134a, 134b of the rotation ring gear <NUM> lock the knob housing <NUM> thereto, rotation of the rotation ring gear <NUM> results in a rotation of the knob housing <NUM> relative to the coupling mechanism <NUM> and around the input shafts <NUM>, <NUM>, <NUM>. The outer tube <NUM> of the adapter assembly <NUM> is fastened to the knob housing <NUM> and, as such, rotates with the knob housing <NUM>, which, in turn, causes the surgical loading unit <NUM> to rotate about the longitudinal axis of the adapter assembly <NUM>.

Turning now to <FIG>, another embodiment of an adapter assembly is shown and is generally referred to by reference character <NUM>. Adapter assembly <NUM> has several identical or similar components as those discussed hereinabove with regard to adapter assembly <NUM>. Accordingly, many of the features of adapter assembly <NUM> will not be discussed in further detail. Additionally, features that are common to both adapter assembly <NUM> and adapter assembly <NUM> may be referred to by the same reference number.

Adapter assembly <NUM> includes structure to help limit, prevent or correct unintentional articulation of the end effector <NUM>. For instance, during manual rotation of knob housing 22a to rotate end effector <NUM> and outer tube <NUM> about the central longitudinal axis "X," for instance, the angle of articulation of end effector <NUM> may also change. As shown in <FIG>, this unintentional change in the angle of articulation of end effector <NUM> may occur during manual rotation of the knob housing 22a in the general direction of arrow "M," when the cam housing <NUM> remains in its rotational position (e.g., due to the engagement between the articulation input shaft <NUM> and an associated drive member 13a of the handle assembly <NUM>) (see <FIG> and <FIG>). Knob housing 22a is non-rotationally connected to a distal bushing 22b which is non-rotationally connected to ring gear <NUM>. In this manner, manual rotation of knob housing 22a results in rotation of distal bushing 22b, and in turn rotation of ring gear <NUM>.

Referring now to <FIG>, a sensor assembly <NUM> may be used to determine whether the articulation movement is unintentional, such as during manual rotation of the knob housing 22a (<FIG> and <FIG>). Here, the sensor assembly <NUM> includes sensors <NUM> (e.g., Hall effect sensors) and a magnet <NUM> (e.g., a refrigerator-type magnet or magnet having appropriately alternating north/south oriented poles). The sensors <NUM> are mounted in quadrature on a printed circuit board <NUM> within adapter assembly <NUM>. The magnet <NUM> is mounted to, and circumferentially around, the ring gear <NUM> at a location that is detectable by sensors <NUM>, as shown in <FIG>. The sensors <NUM> relay the information relating to the rotation of the ring gear <NUM> to a controller or software <NUM> on the printed circuit board <NUM>, to signify a manual rotation of the knob housing <NUM>, and thus an unintentional articulation of the end effector <NUM>.

To help limit, prevent or correct the unintentional articulation of the end effector <NUM>, the adapter assembly <NUM> includes software <NUM>, and at least one sensor assembly, as discussed below. Generally, the sensor assembly detects unintentional movement of first and/or second articulation links <NUM>, <NUM>, communicates with the software <NUM>, and the software <NUM> sends a signal to the drive member 13a (or a different motor) to make the necessary adjustments to return the first and/or second articulation links <NUM>, <NUM> (and accompanying sensor assembly or portion thereof) to the desired position (see <FIG>).

The software <NUM> may be included on a printed circuit board <NUM> that is located on or within a portion of surgical instrument <NUM>, and may communicate with the sensor assembly(ies) and/or drive member 13a (<FIG>) with electrical connections such as pins, ribbons, or wires, or may communicate wirelessly. For example, <FIG> and <FIG> illustrate the printed circuit board <NUM> within adapter assembly <NUM>. Alternatively, the software <NUM> may be located at a remote location and communicate with the sensor assembly(ies) and/or drive member 13a wirelessly.

A variety of different types of sensor assemblies may be used in connection with adapter assembly <NUM> to detect movement of the first and/or second articulation links <NUM>, <NUM>. For instance, adapter assembly <NUM> may include a giant magnetoresistive (GMR) sensor, a flat resistive sensor, a potentiometer sensor, an optical sensor, a sonar sensor, an inductive sensor, and/or other suitable sensors.

With particular reference to <FIG> and <FIG> adapter assembly <NUM> is shown including a first type of sensor assembly <NUM>, which includes a magnetic or GMR sensor <NUM> and a corresponding magnet <NUM>. The GMR sensor <NUM> (e.g., model number AAK001-14E, manufactured by NVE Corporation) is disposed at least partially within an inner tube <NUM> of the adapter assembly <NUM>. The magnet <NUM> is disposed in engagement with the first articulation link <NUM>. GMR sensor <NUM> is electrically connected to software <NUM> (e.g., in the printed circuit board <NUM> or controller) via electrical ribbon <NUM> (<FIG>). Since the first and second articulation links <NUM>, <NUM> move together (in opposite directions), the inclusion of the magnet <NUM> in engagement with a single articulation link is effective. The present disclosure also includes embodiments where the GMR sensor <NUM> is disposed in engagement with the first articulation link <NUM>, and the magnet is disposed at least partially within the inner tube <NUM> of the adapter assembly <NUM>.

In use, GMR sensor <NUM> senses the position of the magnet <NUM> (and thus first articulation link <NUM>) relative thereto. The relative position (or displacement) of the magnet <NUM> and the first articulation link <NUM> corresponds to the amount of articulation of the end effector <NUM>, as discussed above. This positional information is relayed to the software <NUM>. The software <NUM> includes data regarding the desired amount of articulation of the end effector <NUM>, and the associated desired position of the first articulation link <NUM>/magnet <NUM>. The desired amount of articulation of the end effector <NUM> can be ascertained by analyzing the amount of rotation of the articulation input shaft <NUM>.

Next, the software <NUM> compares the actual, measured position of the magnet <NUM> with the desired potion of the magnet <NUM>, and sends a signal to drive member 13a to move the first articulation link <NUM> a sufficient distance proximally or distally such that the desired position of the first articulation link <NUM>, and thus the desired amount of articulation of the end effector <NUM> is achieved. Additionally, the software <NUM> is capable of constantly or servo controlling the drive member 13a to help ensure non-desired articulation of the end effector <NUM> is limited.

Referring now to <FIG>, adapter assembly <NUM> is shown including a second type of sensor assembly <NUM>, which includes a thin-pot resistive senor <NUM> and a corresponding biasing element (e.g., leaf spring <NUM>). Sensor assembly <NUM> is used to determine the longitudinal position of the first articulation link <NUM> relative to the inner tube <NUM> of the adapter assembly <NUM>. The sensor <NUM> is disposed at least partially within the inner tube <NUM> of the adapter assembly <NUM>, and the leaf spring <NUM> is disposed in engagement with the first articulation link <NUM>, such that the leaf spring <NUM> is in contact with the sensor <NUM> and is configured to slidingly engage the sensor <NUM>. The sensor <NUM> is in communication with the software <NUM> (e.g., in the printed circuit board <NUM> or controller) via wireless communication, for instance. Since the first and second articulation links <NUM>, <NUM> move together (in opposite directions), the inclusion of the leaf spring <NUM> in engagement with a single articulation link is effective. The present disclosure also includes embodiments where the sensor <NUM> disposed in engaged with the first articulation link <NUM>, and the leaf spring <NUM> is disposed at least partially within the inner tube <NUM> of the adapter assembly <NUM>.

In use, the sensor <NUM> senses the position of the leaf spring <NUM> (and thus first articulation link <NUM>) relative thereto. The relative position (or displacement) of the leaf spring <NUM> and the first articulation link <NUM> corresponds directly to the amount of articulation of the end effector <NUM>, as discussed above. This positional information is relayed to the software <NUM>. The software <NUM> includes data regarding the desired amount of articulation of the end effector <NUM>, and the associated desired position of the first articulation link <NUM>/leaf spring <NUM>. The desired amount of articulation of the end effector <NUM> can be ascertained or calculated by analyzing the amount of rotation of the articulation input shaft <NUM> and/or the amount of linear displacement of the first articulation link <NUM> and or the second articulation link <NUM>.

Next, the software <NUM> compares the actual, measured position of the leaf spring <NUM> with the desired potion of the leaf spring <NUM>, and sends a signal to the drive member 13a to move the first articulation link <NUM> a sufficient distance proximally or distally such that the desired position of the first articulation link <NUM>, and thus the desired amount of articulation of the end effector <NUM> is achieved. Additionally, the software <NUM> is capable of constantly or servo controlling the drive member 13a to help ensure non-desired articulation of the end effector <NUM> is limited.

It is also envisioned that drive member 13a includes an encoder that can be monitored during use. Here, if the drive member 13a is mechanically backdriven during rotation of knob <NUM>, the driver member 13a can automatically correct its position such that the amount of non-desired articulation of the end effector <NUM> is limited.

Claim 1:
A surgical instrument (<NUM>), comprising:
a handle assembly (<NUM>) including a first drive member (13a); and
an adapter assembly (<NUM>) configured to selectively engage the handle assembly, the adapter assembly including:
a knob housing (22a);
an outer tube (<NUM>) extending distally from the knob housing and defining a longitudinal axis;
an end effector (<NUM>) extending distally from the outer tube (<NUM>), the end effector is movable from a first position where the end effector is aligned with the longitudinal axis, to a second position where the end effector is disposed at an angle relative to the longitudinal axis;
an articulation link (<NUM>, <NUM>) extending through at least a portion of the outer tube (<NUM>) and disposed in mechanical cooperation with the end effector, wherein longitudinal translation of the articulation link relative to the outer tube causes the end effector to move from its first position to its second position; and
a sensor assembly (<NUM>) including a first portion disposed in mechanical cooperation with the articulation link (<NUM>), and a second portion disposed at least partially within the outer tube (<NUM>), the sensor assembly configured to determine an actual amount of articulation of the end effector based on a distance the articulation link moves longitudinally relative to the outer tube; and
characterized in that the adapter assembly includes a ring gear disposed at least partially within the knob housing and in mechanical cooperation with the first drive member when the adapter assembly is engaged with the handle assembly, wherein rotation of the first drive member causes rotation of the ring gear about the longitudinal axis, which causes longitudinal translation of the articulation link.