Patent Description:
In a motorized surgical stapling and cutting instrument it may be useful to measure the position and velocity of a cutting member in an initial predetermined time or displacement to control speed. Measurement of position or velocity over an initial predetermined time or displacement may be useful to evaluate tissue thickness and to adjust the speed of the remaining stroke based on this comparison against a threshold.

While several devices have been made and used, it is believed that no one prior to the inventors has made or used the device described in the appended claims.

For further background, document <CIT> describes a coupling device, such as a slip ring assembly or an inductive or capacitive coupling in a drive unit or within an associated adapter to transmit imaging signals from a rotating electrical cable within the guidewire drive shaft to the non-rotating electronics within the drive unit.

A shaft assembly is usable with a surgical instrument. The shaft assembly defines a longitudinal axis extending longitudinally through the shaft assembly. The shaft assembly includes a proximal shaft portion including a first sensor and a second sensor. The shaft assembly also includes a distal shaft portion rotatable about the longitudinal axis and relative to the proximal shaft portion. The distal shaft portion includes housing, a first magnet rotatable with the housing, a clutch assembly rotatable relative to the housing to transition the shaft assembly between an articulation engaged state and an articulation disengaged state, and a second magnet rotatable with the clutch assembly. The shaft assembly further includes a control circuit configured to detect a transition from the articulation engaged state to the articulation disengaged state based on output signals from the first sensor and the second sensor.

A shaft assembly is usable with a surgical instrument. The shaft assembly defines a longitudinal axis extending longitudinally through the shaft assembly. The shaft assembly includes a proximal shaft portion including a first sensor and a second sensor. The shaft assembly also includes a distal shaft portion rotatable about the longitudinal axis and relative to the proximal shaft portion. The distal shaft portion includes a housing, a first magnet rotatable with the housing, a clutch assembly rotatable relative to the housing to transition the shaft assembly between an articulation engaged state and an articulation disengaged state, and a second magnet rotatable with the clutch assembly. The shaft assembly further includes a control circuit configured to detect a transition from the articulation engaged state to the articulation disengaged state based on relative rotational positions of the distal shaft portion of the shaft assembly and the clutch assembly.

A shaft assembly is usable with a surgical instrument. The shaft assembly defines a longitudinal axis extending longitudinally through the shaft assembly. The shaft assembly includes a proximal shaft portion including a first sensor configured to generate a first output signal and a second sensor configured to generate a second output signal. The shaft assembly also includes a distal shaft portion. The distal shaft portion includes a clutch assembly rotatable with the distal shaft portion about the longitudinal axis and relative to the proximal shaft portion. The clutch assembly is further rotatable relative to the distal shaft portion to transition the shaft assembly between an articulation engaged state and an articulation disengaged state. The rotation of clutch assembly with the distal shaft portion changes the first output signal. The rotation of the clutch assembly relative to the distal shaft portion changes the second output signal. The shaft assembly also includes a control circuit in electrical communication with the first sensor and the second sensor, wherein the control circuit is configured to detect a change in the second output signal occurring without a corresponding change in the first output signal, and wherein the detected change indicates a transition between the articulation engaged state and the articulation disengaged state.

A surgical instrument includes a surgical end effector, a control circuit, and a connector assembly. The connector assembly includes a first connector comprising a first conductor electrically coupled to the surgical end effector, and a second connector comprising a second conductor spaced apart from the first conductor, wherein the second conductor is electrically coupled to the control circuit, wherein the first connector is rotatable relative to the second connector, wherein the first conductor is capacitively coupled to the second conductor defining a capacitive channel therebetween for transmitting an electrical signal between the end effector and the control circuit.

A surgical instrument includes a surgical end effector, an energy source, and a connector assembly. The connector assembly includes a first connector comprising a first conductor electrically coupled to the surgical end effector, and a second connector comprising a second conductor spaced apart from the first conductor, wherein the second conductor is electrically coupled to the energy source, wherein the first connector is rotatable relative to the second connector, wherein the first conductor is capacitively coupled to the second conductor defining a capacitive channel therebetween for transmitting energy from the energy source to the end effector. The present invention relates to a slip ring assembly where a slip ring can form a capacitor for improved electrical communication. There can be multiple capacitive channels on a single dielectric. The dielectric may be movable with respect to the dielectric. The slip ring may also form a patient isolation barrier, which can be particularly advantageous in robotic surgery.

The unit "inch", as used in the following description, is defined as <NUM> inch = <NUM>.

The features of the various aspects described herein are set forth with particularity in the appended claims. The various aspects, however, both as to organization and methods of operation may be better understood by reference to the following description, taken in conjunction with the accompanying drawings as follows:.

Certain aspects are shown and described to provide an understanding of the structure, function, manufacture, and use of the disclosed devices and methods. Features shown or described in one example may be combined with features of other examples and modifications and variations are within the scope of this disclosure.

The terms "proximal" and "distal" are relative to a clinician manipulating the handle of the surgical instrument where "proximal" refers to the portion closer to the clinician and "distal" refers to the portion located further from the clinician. For expediency, spatial terms "vertical," "horizontal," "up," and "down" used with respect to the drawings are not intended to be limiting and/or absolute, because surgical instruments can used in many orientations and positions.

The terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has" and "having"), "include" (and any form of include, such as "includes" and "including") and "contain" (and any form of contain, such as "contains" and "containing") are open-ended linking verbs. As a result, a surgical system, device, or apparatus that "comprises," "has," "includes" or "contains" one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, an element of a system, device, or apparatus that "comprises," "has," "includes" or "contains" one or more features possesses those one or more features, but is not limited to possessing only those one or more features.

Example devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. Such devices and methods, however, can be used in other surgical procedures and applications including open surgical procedures, for example. The surgical instruments can be inserted into a through a natural orifice or through an incision or puncture hole formed in tissue. The working portions or end effector portions of the instruments can be inserted directly into the body or through an access device that has a working channel through which the end effector and elongated shaft of the surgical instrument can be advanced.

<FIG> depict a motor-driven surgical instrument <NUM> for cutting and fastening that may or may not be reused. In the illustrated examples, the surgical instrument <NUM> includes a housing <NUM> that comprises a handle assembly <NUM> that is configured to be grasped, manipulated, and actuated by the clinician. The housing <NUM> is configured for operable attachment to an interchangeable shaft assembly <NUM> that has an end effector <NUM> operably coupled thereto that is configured to perform one or more surgical tasks or procedures. In accordance with the present disclosure, various forms of interchangeable shaft assemblies may be effectively employed in connection with robotically controlled surgical systems. The term "housing" may encompass a housing or similar portion of a robotic system that houses or otherwise operably supports at least one drive system configured to generate and apply at least one control motion that could be used to actuate interchangeable shaft assemblies. The term "frame" may refer to a portion of a handheld surgical instrument. The term "frame" also may represent a portion of a robotically controlled surgical instrument and/or a portion of the robotic system that may be used to operably control a surgical instrument. Interchangeable shaft assemblies may be employed with various robotic systems, instruments, components, and methods disclosed in <CIT>, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS.

<FIG> is a perspective view of a surgical instrument <NUM> that has an interchangeable shaft assembly <NUM> operably coupled thereto according to one aspect of this disclosure. The housing <NUM> includes an end effector <NUM> that comprises a surgical cutting and fastening device configured to operably support a surgical staple cartridge <NUM> therein. The housing <NUM> may be configured for use in connection with interchangeable shaft assemblies that include end effectors that are adapted to support different sizes and types of staple cartridges, have different shaft lengths, sizes, and types. The housing <NUM> may be employed with a variety of interchangeable shaft assemblies, including assemblies configured to apply other motions and forms of energy such as, radio frequency (RF) energy, ultrasonic energy, and/or motion to end effector arrangements adapted for use in connection with various surgical applications and procedures. The end effectors, shaft assemblies, handles, surgical instruments, and/or surgical instrument systems can utilize any suitable fastener, or fasteners, to fasten tissue. For instance, a fastener cartridge comprising a plurality of fasteners removably stored therein can be removably inserted into and/or attached to the end effector of a shaft assembly.

The handle assembly <NUM> may comprise a pair of interconnectable handle housing segments <NUM>, <NUM> interconnected by screws, snap features, adhesive, etc. The handle housing segments <NUM>, <NUM> cooperate to form a pistol grip portion <NUM> that can be gripped and manipulated by the clinician. The handle assembly <NUM> operably supports a plurality of drive systems configured to generate and apply control motions to corresponding portions of the interchangeable shaft assembly that is operably attached thereto.

<FIG> is an exploded assembly view of a portion of the surgical instrument <NUM> of <FIG> according to one aspect of this disclosure. The handle assembly <NUM> may include a frame <NUM> that operably supports a plurality of drive systems. The frame <NUM> can operably support a "first" or closure drive system <NUM>, which can apply closing and opening motions to the interchangeable shaft assembly <NUM>. The closure drive system <NUM> may include an actuator such as a closure trigger <NUM> pivotally supported by the frame <NUM>. The closure trigger <NUM> is pivotally coupled to the handle assembly <NUM> by a pivot pin <NUM> to enable the closure trigger <NUM> to be manipulated by a clinician. When the clinician grips the pistol grip portion <NUM> of the handle assembly <NUM>, the closure trigger <NUM> can pivot from a starting or "unactuated" position to an "actuated" position and more particularly to a fully compressed or fully actuated position.

The handle assembly <NUM> and the frame <NUM> may operably support a firing drive system <NUM> configured to apply firing motions to corresponding portions of the interchangeable shaft assembly attached thereto. The firing drive system <NUM> may employ an electric motor <NUM> located in the pistol grip portion <NUM> of the handle assembly <NUM>. The electric motor <NUM> may be a DC brushed motor having a maximum rotational speed of approximately <NUM>,<NUM> RPM, for example. In other arrangements, the motor may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. The electric motor <NUM> may be powered by a power source <NUM> that may comprise a removable power pack <NUM>. The removable power pack <NUM> may comprise a proximal housing portion <NUM> configured to attach to a distal housing portion <NUM>. The proximal housing portion <NUM> and the distal housing portion <NUM> are configured to operably support a plurality of batteries <NUM> therein. Batteries <NUM> may each comprise, for example, a Lithium Ion (LI) or other suitable battery. The distal housing portion <NUM> is configured for removable operable attachment to a control circuit board <NUM>, which is operably coupled to the electric motor <NUM>. Several batteries <NUM> connected in series may power the surgical instrument <NUM>. The power source <NUM> may be replaceable and/or rechargeable.

The electric motor <NUM> can include a rotatable shaft (not shown) that operably interfaces with a gear reducer assembly <NUM> mounted in meshing engagement with a with a set, or rack, of drive teeth <NUM> on a longitudinally movable drive member <NUM>. The longitudinally movable drive member <NUM> has a rack of drive teeth <NUM> formed thereon for meshing engagement with a corresponding drive gear <NUM> of the gear reducer assembly <NUM>.

In use, a voltage polarity provided by the power source <NUM> can operate the electric motor <NUM> in a clockwise direction wherein the voltage polarity applied to the electric motor by the battery can be reversed in order to operate the electric motor <NUM> in a counter-clockwise direction. When the electric motor <NUM> is rotated in one direction, the longitudinally movable drive member <NUM> will be axially driven in the distal direction "DD. " When the electric motor <NUM> is driven in the opposite rotary direction, the longitudinally movable drive member <NUM> will be axially driven in a proximal direction "PD. " The handle assembly <NUM> can include a switch that can be configured to reverse the polarity applied to the electric motor <NUM> by the power source <NUM>. The handle assembly <NUM> may include a sensor configured to detect the position of the longitudinally movable drive member <NUM> and/or the direction in which the longitudinally movable drive member <NUM> is being moved.

Actuation of the electric motor <NUM> can be controlled by a firing trigger <NUM> that is pivotally supported on the handle assembly <NUM>. The firing trigger <NUM> may be pivoted between an unactuated position and an actuated position.

Turning back to <FIG>, the interchangeable shaft assembly <NUM> includes an end effector <NUM> comprising an elongated channel <NUM> configured to operably support a surgical staple cartridge <NUM> therein. The end effector <NUM> may include an anvil <NUM> that is pivotally supported relative to the elongated channel <NUM>. The interchangeable shaft assembly <NUM> may include an articulation joint <NUM>. Construction and operation of the end effector <NUM> and the articulation joint <NUM> are set forth in <CIT>, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK. The interchangeable shaft assembly <NUM> may include a proximal housing or nozzle <NUM> comprised of nozzle portions <NUM>, <NUM>. The interchangeable shaft assembly <NUM> may include a closure tube <NUM> extending along a shaft axis SA that can be utilized to close and/or open the anvil <NUM> of the end effector <NUM>.

Turning back to <FIG>, the closure tube <NUM> is translated distally (direction "DD") to close the anvil <NUM>, for example, in response to the actuation of the closure trigger <NUM> in the manner described in the aforementioned reference <CIT>. The anvil <NUM> is opened by proximally translating the closure tube <NUM>. In the anvil-open position, the closure tube <NUM> is moved to its proximal position.

<FIG> is an exploded view of one aspect of an end effector <NUM> of the surgical instrument <NUM> of <FIG> in accordance with one or more aspects of the present disclosure. The end effector <NUM> may include the anvil <NUM> and the surgical staple cartridge <NUM>. In this nonlimiting example, the anvil <NUM> is coupled to an elongated channel <NUM>. For example, apertures <NUM> can be defined in the elongated channel <NUM> which can receive pins <NUM> extending from the anvil <NUM> and allow the anvil <NUM> to pivot from an open position to a closed position relative to the elongated channel <NUM> and surgical staple cartridge <NUM>. A firing bar <NUM> is configured to longitudinally translate into the end effector <NUM>. The firing bar <NUM> may be constructed from one solid section, or in various examples, may include a laminate material comprising, for example, a stack of steel plates. The firing bar <NUM> comprises an E-beam <NUM> and a cutting edge <NUM> at a distal end thereof. In various aspects, the E-beam may be referred to as an I-beam. A distally projecting end of the firing bar <NUM> can be attached to the E-beam <NUM> element in any suitable manner and can, among other things, assist in spacing the anvil <NUM> from a surgical staple cartridge <NUM> positioned in the elongated channel <NUM> when the anvil <NUM> is in a closed position. The E-beam <NUM> also can include a sharpened cutting edge <NUM> that can be used to sever tissue as the E-beam <NUM> is advanced distally by the firing bar <NUM>. In operation, the E-beam <NUM> also can actuate, or fire, the surgical staple cartridge <NUM>. The surgical staple cartridge <NUM> can include a molded cartridge body <NUM> that holds a plurality of staples <NUM> resting upon staple drivers <NUM> within respective upwardly open staple cavities <NUM>. A wedge sled <NUM> is driven distally by the E-beam <NUM>, sliding upon a cartridge tray <NUM> that holds together the various components of the surgical staple cartridge <NUM>. The wedge sled <NUM> upwardly cams the staple drivers <NUM> to force out the staples <NUM> into deforming contact with the anvil <NUM> while the cutting edge <NUM> of the E-beam <NUM> severs clamped tissue.

The E-beam <NUM> can include upper pins <NUM> that engage the anvil <NUM> during firing. The E-beam <NUM> can further include middle pins <NUM> and a bottom foot <NUM> that can engage various portions of the cartridge body <NUM>, cartridge tray <NUM>, and elongated channel <NUM>. When a surgical staple cartridge <NUM> is positioned within the elongated channel <NUM>, a slot <NUM> defined in the cartridge body <NUM> can be aligned with a longitudinal slot <NUM> defined in the cartridge tray <NUM> and a slot <NUM> defined in the elongated channel <NUM>. In use, the E-beam <NUM> can slide through the aligned longitudinal slots <NUM>, <NUM>, and <NUM> wherein, as indicated in <FIG>, the bottom foot <NUM> of the E-beam <NUM> can engage a groove running along the bottom surface of elongated channel <NUM> along the length of slot <NUM>, the middle pins <NUM> can engage the top surfaces of cartridge tray <NUM> along the length of longitudinal slot <NUM>, and the upper pins <NUM> can engage the anvil <NUM>. In such circumstances, the E-beam <NUM> can space, or limit the relative movement between, the anvil <NUM> and the surgical staple cartridge <NUM> as the firing bar <NUM> is moved distally to fire the staples from the surgical staple cartridge <NUM> and/or incise the tissue captured between the anvil <NUM> and the surgical staple cartridge <NUM>. Thereafter, the firing bar <NUM> and the E-beam <NUM> can be retracted proximally allowing the anvil <NUM> to be opened to release the two stapled and severed tissue portions.

Referring to <FIG>, in at least one arrangement, an interchangeable shaft assembly can be used in connection with an RF cartridge <NUM> as well as a surgical staple/fastener cartridge.

The RF surgical cartridge <NUM> includes a cartridge body <NUM> that is sized and shaped to be removably received and supported in the elongate channel <NUM>. For example, the cartridge body <NUM> may be configured to be removable retained in snap engagement with the elongate channel <NUM>. In at least one aspect, the cartridge body <NUM> includes a centrally disposed elongate slot <NUM> that extends longitudinally through the cartridge body to accommodate longitudinal travel of a knife therethrough.

The cartridge body <NUM> is formed with a centrally disposed raised electrode pad <NUM>. The elongate slot <NUM> extends through the center of the electrode pad <NUM> and serves to divide the pad <NUM> into a left pad segment <NUM> and a right pad segment 1720R. A right flexible circuit assembly 1730R is attached to the right pad segment 1720R and a left flexible circuit assembly <NUM> is attached to the left pad segment <NUM>. In at least one arrangement for example, the right flexible circuit 1730R comprises a plurality of wires 1732R that may include, for example, wider wires/conductors for RF purposes and thinner wires for conventional stapling purposes that are supported or attached or embedded into a right insulator sheath/member 1734R that is attached to the right pad 1720R. In addition, the right flexible circuit assembly 1730R includes a "phase one", proximal right electrode 1736R and a "phase two" distal right electrode 1738R. Likewise, the left flexible circuit assembly <NUM> comprises a plurality of wires <NUM> that may include, for example, wider wires/conductors for RF purposes and thinner wires for conventional stapling purposes that are supported or attached or embedded into a left insulator sheath/member <NUM> that is attached to the left pad <NUM>. In addition, the left flexible circuit assembly <NUM> includes a "phase one", proximal left electrode <NUM> and a "phase two" distal left electrode <NUM>. The left and right wires <NUM>, 1732R are attached to a distal micro-chip <NUM> mounted to the distal end portion of the cartridge body <NUM>.

The elongate channel <NUM> includes a channel circuit <NUM> that is supported in a recess <NUM> that extends from the proximal end of the elongate channel <NUM> to a distal location <NUM> in the elongate channel bottom portion <NUM>. The channel circuit <NUM> includes a proximal contact portion <NUM> that contacts a distal contact portion <NUM> of a flexible shaft circuit strip for electrical contact therewith. A distal end <NUM> of the channel circuit <NUM> is received within a corresponding wall recess <NUM> formed in one of the channel walls <NUM> and is folded over and attached to an upper edge <NUM> of the channel wall <NUM>. A serial of corresponding exposed contacts <NUM> are provided in the distal end <NUM> of the channel circuit <NUM>. An end of a flexible cartridge circuit <NUM> is attached to the distal micro-chip <NUM> and is affixed to the distal end portion of the cartridge body <NUM>. Another end is folded over the edge of the cartridge deck surface <NUM> and includes exposed contacts configured to make electrical contact with the exposed contacts <NUM> of the channel circuit <NUM>. Thus, when the RF cartridge <NUM> is installed in the elongate channel <NUM>, the electrodes as well as the distal micro-chip <NUM> are powered and communicate with an onboard circuit board through contact between the flexible cartridge circuit <NUM>, the flexible channel circuit <NUM>, a flexible shaft circuit and slip ring assembly.

<FIG> is another exploded assembly view of portions of the interchangeable shaft assembly <NUM> according to one aspect of this disclosure. The interchangeable shaft assembly <NUM> includes a firing member <NUM> that is supported for axial travel within a shaft spine <NUM>. The firing member <NUM> includes an intermediate firing shaft portion <NUM> that is configured for attachment to a distal portion or bar <NUM>. The intermediate firing shaft portion <NUM> may include a longitudinal slot <NUM> in the distal end thereof which can be configured to receive a tab <NUM> on the proximal end <NUM> of the distal bar <NUM>. The longitudinal slot <NUM> and the proximal end <NUM> can be sized and configured to permit relative movement therebetween and can comprise a slip joint <NUM>. The slip joint <NUM> can permit the intermediate firing shaft portion <NUM> of the firing member <NUM> to be moved to articulate the end effector <NUM> without moving, or at least substantially moving, the bar <NUM>. Once the end effector <NUM> has been suitably oriented, the intermediate firing shaft portion <NUM> can be advanced distally until a proximal sidewall of the longitudinal slot <NUM> comes into contact with the tab <NUM> in order to advance the distal bar <NUM>. Advancement of the distal bar <NUM> causes the E-beam <NUM> to be advanced distally to fire the staple cartridge positioned within the channel <NUM>.

Further to the above, the shaft assembly <NUM> includes a clutch assembly <NUM> which can be configured to selectively and releasably couple the articulation driver <NUM> to the firing member <NUM>. In one form, the clutch assembly <NUM> includes a lock collar, or sleeve <NUM>, positioned around the firing member <NUM> wherein the lock sleeve <NUM> can be rotated between an engaged position in which the lock sleeve <NUM> couples the articulation drive <NUM> to the firing member <NUM> and a disengaged position in which the articulation drive <NUM> is not operably coupled to the firing member <NUM>. When lock sleeve <NUM> is in its engaged position, distal movement of the firing member <NUM> can move the articulation drive <NUM> distally and, correspondingly, proximal movement of the firing member <NUM> can move the articulation drive <NUM> proximally. When lock sleeve <NUM> is in its disengaged position, movement of the firing member <NUM> is not transmitted to the articulation drive <NUM> and, as a result, the firing member <NUM> can move independently of the articulation drive <NUM>.

The lock sleeve <NUM> can comprise a cylindrical, or an at least substantially cylindrical, body including a longitudinal aperture <NUM> defined therein configured to receive the firing member <NUM>. The lock sleeve <NUM> can comprise diametrically-opposed, inwardly-facing lock protrusions <NUM> and an outwardly-facing lock member <NUM>. The lock protrusions <NUM> can be configured to be selectively engaged with the firing member <NUM>. More particularly, when the lock sleeve <NUM> is in its engaged position, the lock protrusions <NUM> are positioned within a drive notch <NUM> defined in the firing member <NUM> such that a distal pushing force and/or a proximal pulling force can be transmitted from the firing member <NUM> to the lock sleeve <NUM>. When the lock sleeve <NUM> is in its engaged position, the second lock member <NUM> is received within a drive notch <NUM> defined in the articulation driver <NUM> such that the distal pushing force and/or the proximal pulling force applied to the lock sleeve <NUM> can be transmitted to the articulation driver <NUM>. In effect, the firing member <NUM>, the lock sleeve <NUM>, and the articulation driver <NUM> will move together when the lock sleeve <NUM> is in its engaged position. On the other hand, when the lock sleeve <NUM> is in its disengaged position, the lock protrusions <NUM> may not be positioned within the drive notch <NUM> of the firing member <NUM> and, as a result, a distal pushing force and/or a proximal pulling force may not be transmitted from the firing member <NUM> to the lock sleeve <NUM>. Correspondingly, the distal pushing force and/or the proximal pulling force may not be transmitted to the articulation driver <NUM>. In such circumstances, the firing member <NUM> can be slid proximally and/or distally relative to the lock sleeve <NUM> and the proximal articulation driver <NUM>.

The shaft assembly <NUM> further includes a switch drum <NUM> that is rotatably received on the closure tube <NUM>. The switch drum <NUM> comprises a hollow shaft segment <NUM> that has a shaft boss <NUM> formed thereon for receive an outwardly protruding actuation pin <NUM> therein. In various circumstances, the actuation pin <NUM> extends through a slot <NUM> into a longitudinal slot <NUM> provided in the lock sleeve <NUM> to facilitate axial movement of the lock sleeve <NUM> when it is engaged with the articulation driver <NUM>. A rotary torsion spring <NUM> is configured to engage the boss <NUM> on the switch drum <NUM> and a portion of the nozzle housing <NUM> as shown in <FIG> to apply a biasing force to the switch drum <NUM>. The switch drum <NUM> can further comprise at least partially circumferential openings <NUM> defined therein which, referring to <FIG> and <FIG>, can be configured to receive circumferential mounts extending from the nozzle halves <NUM>, <NUM> and permit relative rotation, but not translation, between the switch drum <NUM> and the proximal nozzle <NUM>. The mounts also extend through openings <NUM> in the closure tube <NUM> to be seated in recesses <NUM> in the shaft spine <NUM>. However, rotation of the nozzle <NUM> to a point where the mounts reach the end of their respective openings <NUM> in the switch drum <NUM> will result in rotation of the switch drum <NUM> about the shaft axis SA-SA. Rotation of the switch drum <NUM> will ultimately result in the rotation of the actuation pin <NUM> and the lock sleeve <NUM> between its engaged and disengaged positions. Thus, in essence, the nozzle <NUM> may be employed to operably engage and disengage the articulation drive system with the firing drive system in the various manners described in further detail in <CIT>.

The shaft assembly <NUM> can comprise a slip ring assembly <NUM> which can be configured to conduct electrical power to and/or from the end effector <NUM> and/or communicate signals to and/or from the end effector <NUM>, for example. The slip ring assembly <NUM> can comprise a proximal connector flange <NUM> mounted to a chassis flange <NUM> extending from the chassis <NUM> and a distal connector flange <NUM> positioned within a slot defined in the nozzle halves <NUM>, <NUM>. The proximal connector flange <NUM> can comprise a first face and the distal connector flange <NUM> can comprise a second face which is positioned adjacent to and movable relative to the first face. The distal connector flange <NUM> can rotate relative to the proximal connector flange <NUM> about the shaft axis SA-SA. The proximal connector flange <NUM> can comprise a plurality of concentric, or at least substantially concentric, conductors <NUM> defined in the first face thereof. A connector <NUM> can be mounted on the proximal side of the connector flange <NUM> and may have a plurality of contacts, wherein each contact corresponds to and is in electrical contact with one of the conductors <NUM>. Such an arrangement permits relative rotation between the proximal connector flange <NUM> and the distal connector flange <NUM> while maintaining electrical contact therebetween. The proximal connector flange <NUM> can include an electrical connector <NUM> which can place the conductors <NUM> in signal communication with a circuit board mounted to the shaft chassis <NUM>, for example. In at least one instance, a wiring harness comprising a plurality of conductors can extend between the electrical connector <NUM> and the circuit board. Further details regarding slip ring assembly <NUM> may be found in <CIT>.

The shaft assembly <NUM> can include a proximal portion which is fixably mounted to the handle assembly <NUM> and a distal portion which is rotatable about a longitudinal axis. The rotatable distal shaft portion can be rotated relative to the proximal portion about the slip ring assembly <NUM>. The distal connector flange <NUM> of the slip ring assembly <NUM> can be positioned within the rotatable distal shaft portion. Moreover, further to the above, the switch drum <NUM> can also be positioned within the rotatable distal shaft portion. When the rotatable distal shaft portion is rotated, the distal connector flange <NUM> and the switch drum <NUM> can be rotated synchronously with one another. In addition, the switch drum <NUM> can be rotated between a first position and a second position relative to the distal connector flange <NUM>. When the switch drum <NUM> is in its first position, the articulation drive system may be operably disengaged from the firing drive system and, thus, the operation of the firing drive system may not articulate the end effector <NUM> of the shaft assembly <NUM>. When the switch drum <NUM> is in its second position, the articulation drive system may be operably engaged with the firing drive system and, thus, the operation of the firing drive system may articulate the end effector <NUM> of the shaft assembly <NUM>. When the switch drum <NUM> is moved between its first position and its second position, the switch drum <NUM> is moved relative to distal connector flange <NUM>.

In various examples, the shaft assembly <NUM> can comprise at least one sensor configured to detect the position of the switch drum <NUM>. The distal connector flange <NUM> can comprise a Hall effect sensor <NUM>, for example, and the switch drum <NUM> can comprise a magnetic element, such as permanent magnet <NUM>, for example. The Hall effect sensor <NUM> can be configured to detect the position of the permanent magnet <NUM>. When the switch drum <NUM> is rotated between its first position and its second position, the permanent magnet <NUM> can move relative to the Hall effect sensor <NUM>. In various examples, Hall effect sensor <NUM> can detect changes in a magnetic field created when the permanent magnet <NUM> is moved. The Hall effect sensor <NUM> can be in signal communication with a control circuit, for example. Based on the signal from the Hall effect sensor <NUM>, a microcontroller on the control circuit can determine whether the articulation drive system is engaged with or disengaged from the firing drive system.

A surgical instrument may not be able to use a rotatable shaft assembly effectively by using general wires to communicate power and signals between a fixed shaft portion and a rotatable shaft portion of the shaft assembly because the wires may get twisted or even damaged due to the repeated rotation of the shaft assembly. One way to overcome this deficiency may be to use a ring assembly instead of wires to communicate power and signals to the rotatable shaft portion. For example, a first flange with electrodes may be attached to the fixed shaft portion and a second flange with electrodes may rotate relative to the electrodes of the first flange. A gap is necessarily formed between the first flange and the second flange to permit the rotation of the second flange relative to the first flange. In order to maintain an electrical connection during the rotation of the rotatable shaft portion, the electrodes of the first and second flanges may be exposed at an interface therebetween. The gap may permit water and/or other body fluid ingress into the area between the first and second flanges where the electrode interface resides. Accordingly, the electrode interface may become exposed to water and other body fluids during surgery. Upon touching the exposed electrodes, the water and/or body fluids may cause signal noise or even loss of power/signals.

Aspects of the present disclosure improve slip ring assemblies in surgical instruments that that are exposed to water and/or body fluids during their operation. In one arrangement, a shaft assembly may include a proximal shaft portion that can be fixably connected to a body of a surgical instrument and a distal shaft portion rotatable relative to the proximal shaft portion. The slip ring assembly may include a proximal slip ring in the proximal shaft portion and a distal slip ring in the shaft distal portion. Each of the proximal slip ring and the distal slip ring may include one or more conductors mounted on each of the proximal and distal slip rings. The conductors on the proximal and distal slip rings may be coated with a water-proof insulative layer to provide a waterproof barrier to prevent water or fluids which may be generated during surgery from reaching the conductors. A dielectric layer (e.g., high-k dielectric, such as PZT) may be located between the conductors on the proximal and distal slip rings, and the conductors of the proximal slip ring and the conductors of the distal slip ring may form capacitive channels therebetween. These capacitive channels may be used to communicate power and signals from the fixed body portion to the rotatable shaft assembly portion (e.g., an end effector) using capacitive coupling.

In this way, aspects of the present disclosure may advantageously allow the conductors to be covered with a water-proof insulative layer by forming a capacitive channel between the conductors in the distal and proximal slip rings rather than a direct connection, which may necessarily expose some portions of the electrodes to the outside. Accordingly, aspects of the present disclosure may prevent signal noise and loss of power and signals by providing an insulative barrier to prevent water or fluids from reaching the electrodes.

<FIG> shows a perspective partial cut-away view of a slip ring assembly <NUM> according to one aspect of this disclosure and <FIG> shows a cross-sectional view of a portion of the slip ring assembly <NUM> of <FIG> according to one aspect of this disclosure. The slip ring assembly <NUM> may be included in a shaft assembly (e.g., shaft assembly <NUM>). The slip ring assembly <NUM> may be configured to conduct electrical power to and/or from an end effector (e.g., end effector <NUM>) and/or communicate signals to and/or from the end effector. The slip ring assembly may include a proximal portion <NUM> and a distal portion <NUM>. The proximal portion <NUM> may be fixably connected to a body (e.g., handle assembly <NUM> or a chassis flange <NUM> of a proximal shaft portion of a shaft assembly) of a surgical instrument (e.g., surgical instrument <NUM>). The distal portion <NUM> may be fixedly connected to a distal shaft portion of a shaft assembly. The distal portion <NUM> may be rotatable relative to the proximal portion <NUM>, for example, about a longitudinal axis. As illustrated in <FIG> and <FIG>, the slip ring assembly <NUM> may include a proximal slip ring <NUM> and one or more conductors <NUM> mounted on the proximal slip ring <NUM>. The proximal slip ring <NUM> and the conductors <NUM> in the proximal portion <NUM> may be coated with a first water-proof insulative layer <NUM> to provide a waterproof barrier to prevent water or fluids which may be generated during surgery from reaching the conductors <NUM>. In an example aspect, the first water-proof insulative layer <NUM> may cover the entire conductors <NUM>.

In the distal portion <NUM>, the slip ring assembly <NUM> may also include a distal slip ring <NUM> and one or more conductors <NUM> mounted on the distal slip ring <NUM>. The distal slip ring <NUM> and the conductors <NUM> in the distal portion <NUM> may be coated with a second water-proof insulative layer <NUM> to provide a waterproof barrier to prevent water or fluids from reaching the conductors <NUM>. In an example aspect, the second water-proof insulative layer <NUM> may cover the entire conductors <NUM>. In an example aspect, the first and second water-proof insulative layers <NUM>, <NUM> may comprise an electrically insulative and water-resistant material. In an example aspect, the first and second water-proof insulative layers <NUM>, <NUM> also may comprise a slippery material.

The proximal and distal slip rings <NUM>, <NUM> may be positioned within a slot defined in nozzle halves (e.g., nozzle halves <NUM>, <NUM>). In an example aspect, the proximal and distal slip rings <NUM>, <NUM> may be manufactured from or coated with an electrically non-conductive material. The distal slip ring <NUM> may rotate relative to the proximal slip ring <NUM> about the shaft axis SA-SA.

In an example aspect, a dielectric layer <NUM> may be located between the first water-proof insulative layer <NUM> and the second water-proof insulative layer <NUM>. In an example aspect, the dielectric layer <NUM> may be fixably connected to the first water-proof insulative layer <NUM> in the proximal portion <NUM>. In an example aspect, the dielectric layer <NUM> may be in direct contact with the second water-proof insulative layer <NUM> and the second water-proof insulative layer <NUM> may comprise a slippery material such that the distal portion <NUM> (e.g., the distal slip ring <NUM> and the second water-proof insulative layer <NUM>) rotates relative to the dielectric layer <NUM> smoothly with less friction with the contacted surface of the dielectric layer <NUM>. In another example aspect, there may be an air gap between the dielectric layer <NUM> and the second water-proof insulative layer <NUM>.

In another example aspect, the dielectric layer <NUM> may be fixably connected to the second water-proof insulative layer <NUM> in the distal portion <NUM>. In this case, in an example aspect, the dielectric layer <NUM> may be in direct contact with the first water-proof insulative layer <NUM> and the first water-proof insulative layer <NUM> may comprise a slippery material such that the distal portion <NUM> (e.g., the distal slip ring <NUM> and the dielectric layer <NUM>) rotates relative to the first water-proof insulative layer <NUM> smoothly with less friction with the contacted surface of the first water-proof insulative layer <NUM>. In another example aspect, there may be an air gap between the dielectric layer <NUM> and the first water-proof insulative layer <NUM>.

In another example aspect, the dielectric layer <NUM> may be free from both of the first water-proof insulative layer <NUM> and the second water-proof insulative layer <NUM>, for example, by being fixably connected to another component (e.g., nozzle halves <NUM>, <NUM>) of the surgical instrument. In this case, the dielectric layer <NUM> may be in direct contact with at least one of the first water-proof insulative layer <NUM> and the second water-proof insulative layer <NUM>, and at least one of the first water-proof insulative layer <NUM> and the second water-proof insulative layer <NUM> may comprise a slippery material such that the distal portion <NUM> (e.g., the distal slip ring <NUM> and the second water-proof insulative layer <NUM>) rotates relative to the dielectric layer <NUM> smoothly with less friction. In another example aspect, there may be an air gap between the dielectric layer <NUM> and the first water-proof insulative layer <NUM> and/or between the dielectric layer <NUM> and the second water-proof insulative layer <NUM>.

In an example aspect, the thickness <NUM> of the conductors <NUM> (or conductors <NUM>) may be in the range of about <NUM> inches to about <NUM> inches, preferably in the range of about <NUM> inches to about <NUM> inches, more preferably in the range of about <NUM> inches to about <NUM> inches. In another example aspect, the conductors <NUM>, <NUM> may have any other suitable thickness. In an example aspect, the vertical distance <NUM> between the conductors <NUM> and the dielectric layer <NUM> may be very small, for example, in the range of about <NUM> inches to about <NUM> inches, preferably in the range of about <NUM> inches to about <NUM> inches, more preferably in the range of about <NUM> inches to about <NUM> inches. In another example aspect, the conductors <NUM> and the dielectric layer <NUM> may have any other suitable distance. In an example aspect, a vertical distance between the conductors <NUM> and the dielectric layer <NUM> may be similar to the vertical distance <NUM>. In an example aspect, the thickness <NUM> of the dielectric layer <NUM> may be very thin, for example, in the range of about <NUM> inches to about <NUM> inches, preferably in the range of about <NUM> inches to about <NUM> inches, more preferably in the range of about <NUM> inches to about <NUM> inches. In another example aspect, the dielectric layer <NUM> may have any other suitable thickness.

The proximal slip ring <NUM> may be fixably connected to the body of the surgical instrument. For example, the proximal slip ring <NUM> and the conductors <NUM> of the proximal slip ring <NUM> may be connected to a shaft circuit board <NUM> (e.g., shaft circuit board <NUM>) though a first electrical connector <NUM> (e.g., electrical connector <NUM>) as illustrated in <FIG>. The circuit board <NUM> may include a control circuit <NUM> (e.g., a micro-chip or a microprocessor) configured to control the power and signals delivered to an end effector (e.g., end effector <NUM>). The distal slip ring <NUM> and the conductors <NUM> of the distal slip ring <NUM> may be connected to the end effector through a second electrical connector <NUM>.

The conductors <NUM> of the proximal slip ring <NUM> and the conductors <NUM> of the distal slip ring <NUM> form capacitive channels therebetween. The control circuit <NUM> may be configured to communicate the power and signals (e.g., data or any other signals) to the end effector that is electrically connected to the distal slip ring <NUM> using capacitive coupling through the capacitive channels. The control circuit may use AC current to communicate power and signals to and/or from the end effector.

In an example aspect, the first and second slip rings <NUM>, <NUM> may be in a ring shape as illustrated in <FIG>. In another example aspect, the first and second slip rings <NUM>, <NUM> may have any other suitable shape. In an example aspect, the conductors <NUM>, <NUM> may comprise a metallic electrode. In another example aspect, the conductors <NUM>, <NUM> may comprise any other electrically conductive material. In an example aspect, each of the conductors <NUM> on the proximal slip ring <NUM> may be matched with one of the conductors <NUM> on the distal slip ring <NUM> and the matched conductors may be facing each other. For example, as illustrated in <FIG>, a conductor 2020A is matched with a conductor 2120A, and a conductor 2020B is matched with a conductor 2120B. In an example aspect, the conductors <NUM>, <NUM> may be in a concentric circle shape, as illustrated in <FIG>, such that the matched conductors (e.g., 2020A-2120A; 2020B-2120B) may continue to face each other while the distal portion <NUM> of the slip ring assembly <NUM> is rotating, maintaining the capacitive channels formed therebetween continuously. In another example aspect, the conductors <NUM>, <NUM> may have any other suitable shape.

In an example aspect, the dielectric layer <NUM> may comprise a high-k dielectric material, such as PZT (lead zirconate titanate), titanium oxide (TiO<NUM>), tantalum oxide (Ta<NUM>O<NUM>), cesium oxide (CeO<NUM>), and aluminum oxide (Al<NUM>O<NUM>). The materials may be used alone or in any combination thereof. As used herein, a high-k dielectric material may refer to a dielectric material having a high dielectric constant value k (e.g., greater than the k value of silicon dioxide which is around <NUM>). In an example aspect, the dielectric layer <NUM> may comprise a dielectric material with a very high dielectric constant (e.g., greater than about <NUM> to about <NUM>), such as PZT. By using a dielectric material with a very high dielectric constant, the capacitive channels formed in the slip ring assembly <NUM> may be able to have enough capacitance while keeping the thickness of the dielectric layer <NUM> very thin (e.g., less than from <NUM> to <NUM> inches) without suffering from unacceptable levels of leakage current or catastrophic breakdown. In another example aspect, the dielectric layer <NUM> may comprise any other suitable dielectric material (e.g., medium to low dielectric constant materials, such as silicon dioxide). In an example, the dielectric layer <NUM> may be deposited on one of the slip rings above the first water-proof insulative layer <NUM> or the second water-proof insulative layer <NUM> (e.g., vapor deposition). In an example, the dielectric layer <NUM> may be provided as a disk or wafer layer.

In an example aspect, only one of the slip rings <NUM>, <NUM> may include a water-proof insulative layer. For example, if the distal slip ring <NUM> and the conductors <NUM> on the distal slip ring <NUM> are coated with a water-proof insulative layer, the proximal slip ring <NUM> and the conductors <NUM> on the proximal slip ring <NUM> may be coated with the dielectric layer <NUM> (e.g., vapor deposition of a dielectric material) directly without a separate water-proof insulative layer therebetween. In this case, the dielectric layer <NUM> may be water-resistant and prevent water or fluids from reaching the conductors <NUM>. In another example aspect, if the proximal slip ring <NUM> and the conductors <NUM> on the proximal slip ring <NUM> are coated with a water-proof insulative layer, the distal slip ring <NUM> and the conductors <NUM> on the distal slip ring <NUM> may be coated with the dielectric layer <NUM> (e.g., vapor deposition of a dielectric material) directly without a separate water-proof insulative layer therebetween.

<FIG> shows a cross-sectional view of a portion of a slip ring assembly <NUM> according to another aspect of this disclosure. The slip ring assembly <NUM> may be included in a shaft assembly (e.g., shaft assembly <NUM>). The slip ring assembly <NUM> may have a proximal portion <NUM> and a distal portion <NUM>. The proximal portion <NUM> may be fixably connected to a body (e.g., handle assembly <NUM>) of a surgical instrument (e.g., surgical instrument <NUM>). The distal portion <NUM> may be rotatable relative to the proximal portion <NUM>. As illustrated in <FIG>, the slip ring assembly <NUM> may include a proximal slip ring <NUM> and one or more conductors <NUM> mounted on the proximal slip ring <NUM> in the proximal portion <NUM>. The proximal slip ring <NUM> and the conductors <NUM> may be coated with a first dielectric layer <NUM>. In an example aspect, the first dielectric layer may cover the entire conductors <NUM>. The first dielectric layer <NUM> may provide a waterproof barrier to prevent water or fluids which may be generated during surgery from reaching the conductors <NUM>.

In an example aspect, the slip ring assembly <NUM> also may include a distal slip ring <NUM> and one or more conductors <NUM> mounted on the distal slip ring <NUM> in the distal portion <NUM>. The distal slip ring <NUM> and the conductors <NUM> may be coated with a second dielectric layer <NUM>. In an example aspect, the second dielectric layer <NUM> may cover the entire conductors <NUM>. The second dielectric layer <NUM> may provide a waterproof barrier to prevent water or fluids which may be generated during surgery from reaching the conductors <NUM>. The conductors <NUM>, <NUM> may form capacitive channels therebetween.

In an example aspect, the first and second dielectric layers <NUM>, <NUM> may comprise a high-k dielectric material, such as PZT (lead zirconate titanate), titanium oxide (TiO<NUM>), tantalum oxide (Ta<NUM>O<NUM>), cesium oxide (CeO<NUM>), aluminum oxide (Al<NUM>O<NUM>), or an epoxy material with a high k value (e.g., having a dielectric constant higher than <NUM>). The materials may be used alone or in any combination thereof. In an example aspect, at least one of the first and second dielectric layers <NUM>, <NUM> may comprise a dielectric material with a very high dielectric constant (e.g., greater than about <NUM> to about <NUM>), such as PZT. In another example aspect, the first and second dielectric layers <NUM>, <NUM> may comprise any other suitable dielectric material (e.g., medium to low dielectric constant materials, such as silicon dioxide).

In an example aspect, the first dielectric layer <NUM> may comprise a dielectric material different from the second dielectric layer <NUM>. For example, the first dielectric layer <NUM> may comprise an epoxy material while the second dielectric layer <NUM> comprises titanium oxide or PZT (e.g., vapor deposited dielectric layer). In another example aspect, the first dielectric layer <NUM> may comprise a dielectric material that is the same as the second dielectric layer <NUM>.

In an example aspect, the slip ring assembly <NUM> may include a third dielectric layer <NUM> fixably attached on the first dielectric layer <NUM>. For example, a dielectric disc/wafer may be glued to the first dielectric layer <NUM> or a dielectric layer is vapor deposited on the first dielectric layer <NUM>. In this case, in an example, there may be an air gap <NUM> between the second dielectric layer <NUM> and the third dielectric layer <NUM> to facilitate a smooth rotation of the distal portion <NUM> relative to the third dielectric layer <NUM>. In another example aspect, there may be no air gap between the second dielectric layer <NUM> and the third dielectric layer <NUM>, and a slippery insulative layer may be coated either on the second dielectric layer <NUM> or on the third dielectric layer <NUM>.

In another example aspect, the third dielectric layer <NUM> may be fixably attached on the second dielectric layer <NUM>. In this case, in an example, there may be an air gap between the first dielectric layer <NUM> and the third dielectric layer <NUM> to facilitate a smooth rotation of the distal portion <NUM>, including the third dielectric layer <NUM>, relative to the first dielectric layer <NUM>. In another example aspect, there may be no air gap between the first dielectric layer <NUM> and the third dielectric layer <NUM>, and a slippery insulative layer may be coated either on the first dielectric layer <NUM> or on the third dielectric layer <NUM>.

In another example aspect, the third dielectric layer <NUM> may be free from both of the first dielectric layer <NUM> and the second dielectric layer <NUM>, for example, by being fixably connected to another component (e.g., nozzle halves <NUM>, <NUM>) of the surgical instrument. In this case, in an example, there may be an air gap between the third dielectric layer <NUM> and at least one of the first and second dielectric layers <NUM>, <NUM>. In another example aspect, there may be no air gap, but instead there may be a slippery insulative layer between the third dielectric layer <NUM> and at least one of the first and second dielectric layers <NUM>, <NUM>.

In an example aspect, the third dielectric layer <NUM> may comprise a high-k dielectric material, such as PZT (lead zirconate titanate), titanium oxide (TiO<NUM>), tantalum oxide (Ta<NUM>O<NUM>), cesium oxide (CeO<NUM>), aluminum oxide (Al<NUM>O<NUM>) or an epoxy material with a high k value (e.g., having a dielectric constant higher than <NUM>). The materials may be used alone or in any combination thereof. In an example aspect, the third dielectric layer <NUM> may comprise a dielectric material with a very high dielectric constant (e.g., greater than about <NUM> to about <NUM>), such as PZT. In another example aspect, the third dielectric layer <NUM> may comprise any other suitable dielectric material (e.g., medium to low dielectric constant materials, such as silicon dioxide).

In an example aspect, the dielectric constant of the second dielectric layer <NUM> and/or the third dielectric layer <NUM> may be greater than the dielectric constant of the first dielectric layer <NUM>. In another example aspect, the dielectric constant of the first dielectric layer <NUM> may be greater than the dielectric constant of the second dielectric layer <NUM> and/or the third dielectric layer <NUM>. In an example aspect, the third dielectric layer <NUM> may comprise a dielectric material different from the second dielectric layer <NUM>. In another example aspect, the third dielectric layer <NUM> may comprise a dielectric material that is the same as the second dielectric layer <NUM>.

In an example aspect, the thickness <NUM> of the conductors <NUM> and/or the thickness <NUM> of the conductors <NUM> may be in the range of about <NUM> inches to about <NUM> inches, preferably in the range of about <NUM> inches to about <NUM> inches, more preferably in the range of about <NUM> inches to about <NUM> inches. In another example aspect, the conductors <NUM>, <NUM> may have any other suitable thickness. In an example aspect, the thickness <NUM> of the second dielectric layer <NUM> may be in the range of about <NUM> inches to about <NUM> inches, preferably in the range of about <NUM> inches to about <NUM> inches, more preferably in the range of about <NUM> inches to about <NUM> inches. In another example aspect, the second dielectric layer <NUM> may have any other suitable thickness. In an example aspect, the air gap <NUM> between the third dielectric layer <NUM> and the second dielectric layer <NUM> (or any other air gap discussed herein) may be very thin, for example, less than <NUM> inches, preferably less than <NUM> inches, more preferably less than <NUM> inches. In another example aspect, the air gap <NUM> may have any other suitable distance.

In an example aspect, the vertical distance <NUM> between the conductors <NUM> and the third dielectric layer <NUM> may be very small, for example, in the range of about <NUM> inches to about <NUM> inches, preferably in the range of about <NUM> inches to about <NUM> inches, more preferably in the range of about <NUM> inches to about <NUM> inches. In another example aspect, the conductors <NUM> and the third dielectric layer <NUM> may have any other suitable distance. In an example aspect, the thickness <NUM> of the third dielectric layer <NUM> may be very thin, for example, in the range of about <NUM> inches to about <NUM> inches, preferably in the range of about <NUM> inches to about <NUM> inches, more preferably in the range of about <NUM> inches to about <NUM> inches. In another example aspect, the third dielectric layer <NUM> may have any other suitable thickness.

Remaining features and characteristics of the slip ring assembly <NUM> illustrated and described with respect to <FIG> in which the conductors <NUM>, <NUM> are mounted on the slip rings <NUM>, <NUM> can otherwise be similar or the same as those described with the embodiments depicted in <FIG>, including but not limited to components, arrangements, and shapes of any of the slip rings <NUM>, <NUM> or the conductors <NUM>, <NUM>, as well as the possible presence of electrical connectors <NUM>, <NUM>, shaft circuit board <NUM>, control circuit <NUM> as described and illustrated herein.

<FIG> shows a block diagram of the circuit of a surgical instrument, illustrating interfaces between a control circuit <NUM> (e.g., control circuit <NUM>), a power source <NUM> (e.g., power source <NUM>), a slip ring assembly <NUM> (e.g., slip ring assemblies <NUM>, <NUM>), and an end effector <NUM> (e.g., end effector <NUM>) according to one aspect of this disclosure. As illustrated in <FIG>, the slip ring assembly <NUM> may include one or more capacitive channels 2440A-C formed by conductors on the proximal and distal slip rings. The control circuit <NUM> may be configured to communicate power and signals to the end effector <NUM> using capacitive coupling through the capacitive channels 2440A-C.

In an example aspect, each capacitive channel 2440A-C may receive/transmit different types of signals/power. For example, the control circuit <NUM> may use a first capacitive channel 2440A for a first signal or data, a second capacitive channel 2440B for a second signal or data, and a third capacitive channel 2440C for power. In another example embodiment, the control circuit <NUM> may receive/transmit different types of signals/power using the same capacitive channel. For example, the first capacitive channel 2440A may be used to receive/transmit both the power and signals.

The foregoing description has set forth aspects of devices and/or processes via the use of block diagrams, flowcharts, and/or examples, which may contain one or more functions and/or operation. Each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In one aspect, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), Programmable Logic Devices (PLDs), circuits, registers and/or software components, e.g., programs, subroutines, logic and/or combinations of hardware and software components, logic gates, or other integrated formats. Some aspects disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure.

The mechanisms of the disclosed subject matter are capable of being distributed as a program product in a variety of forms, and that an illustrative aspect of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include the following: a recordable type medium such as a floppy disk, a hard disk drive, a Compact Disc (CD), a Digital Video Disk (DVD), a digital tape, a computer memory, etc.; and a transmission type medium such as a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link (e.g., transmitter, receiver, transmission logic, reception logic, etc.).

Claim 1:
A slip ring assembly (<NUM>) for use with a surgical shaft assembly (<NUM>), the slip ring assembly comprising:
a first connector (<NUM>);
a first conductor (<NUM>) mounted on the first connector (<NUM>);
a first dielectric layer (<NUM>) on the first conductor (<NUM>);
a second connector (<NUM>) rotatable relative to the first connector (<NUM>);
a second conductor (<NUM>) mounted on the second connector (<NUM>);
a second layer (<NUM>) on the second conductor (<NUM>); wherein the first dielectric layer and the second layer are located between the first and second connectors; and
wherein the first conductor (<NUM>) and the second conductor (<NUM>) are configured to form a capacitive channel therebetween for communicating power and/or signals from the first conductor to the second conductor;
characterized in that the second layer (<NUM>) is a dielectric layer.