Patent Description:
Robotic surgical systems are increasingly utilized in various different surgical procedures. Some robotic surgical systems include a console supporting a robotic arm. One or more different surgical instruments may be configured for use with the robotic surgical system and selectively mountable to the robotic arm. The robotic arm provides one or more inputs to the mounted surgical instrument to enable operation of the mounted surgical instrument, e.g., to rotate, articulate, and/or actuate the mounted surgical instrument.

<CIT> discloses a sterile interface module for coupling an electromechanical robotic surgical instrument to a robotic surgical assembly. The surgical instrument includes an end effector and is configured to be actuated by the robotic surgical assembly. The sterile interface module includes a body member and a drive assembly. The body member is configured to selectively couple the surgical instrument to the robotic surgical assembly. The body member is formed of a dielectric material. The drive assembly is supported within the body member and is configured to transmit rotational forces from the robotic surgical assembly to the surgical instrument to actuate the surgical instrument to enable the surgical instrument to perform a function.

<CIT> discloses an inspection instrument having a generally elongated flexible shaft extending between a control head at a proximal end and an objective assembly at a distal end. A bending section adjacent the objective assembly enables movement of the objective assembly between a neutral position and angularly disposed positions. A control member on the control head causes deflection of the objective assembly by means of a pair of operating cables.

which are operatively connected at their opposite ends to the control member and to the objective assembly. A compensating mechanism engages the cables intermediate their ends and is effective to guard the cable against excessive loads and also to readily accommodate variations in the working length of the cables as occurs when the cables are permanently stretched.

<CIT> discloses a low friction, low inertia, six-axis force feedback input device comprising an arm with double-jointed, tendon-driven revolute joints, a decoupled tendon-driven wrist, and a base with encoders and motors. The input device functions as a master robot manipulator of a microsurgical teleoperated robot system including a slave robot manipulator coupled to an amplifier chassis, which is coupled to a control chassis, which is coupled to a workstation with a graphical user interface. The amplifier chassis is coupled to the motors of the master robot manipulator and the control chassis is coupled to the encoders of the master robot manipulator. A force feedback can be applied to the input device and can be generated from the slave robot to enable a user to operate the slave robot via the input device without physically viewing the slave robot. Also, the force feedback can be generated from the workstation to represent fictitious forces to constrain the input device's control of the slave robot to be within imaginary predetermined boundaries.

The invention is defined by the amended claims.

As used herein, the term "distal" refers to the portion that is being described which is closer to a patient (farther from the surgeon or robot holding the device), while the term "proximal" refers to the portion that is being described which is farther from a patient (closer to the surgeon or robot holding the device). The terms "about," substantially," and the like, as utilized herein, are meant to account for manufacturing, material, environmental, use, and/or measurement tolerances and variations. Further, to the extent consistent, any of the aspects described herein may be used in conjunction with any or all of the other aspects described herein.

Provided in accordance with aspects of the present disclosure is an articulation assembly for a robotic surgical instrument including first and second base plates, a plurality of lead screws extending between the first and second base plates, a collar disposed in threaded engagement about each of the lead screws, and an articulation cable coupled to each of the collars. Each lead screw is rotatable but longitudinally fixed relative to the first and second base plates. Each collar is configured to translate longitudinally along a corresponding one
of the lead screws in response to rotation of the corresponding lead screw. Each articulation cable defines or has engaged therewith a threaded shaft. A threaded nipple is disposed in threaded engagement about each of the threaded shafts. Each threaded nipple is engaged with one of the collars to thereby engage each of the articulation cables with a corresponding one of the collars such that longitudinal translation of the corresponding collar pushes or pulls the corresponding articulation cable. Each threaded nipple is configured for further threading or unthreading about the corresponding threaded shaft to vary a pre-tension on the corresponding articulation cable.

In an aspect of the present disclosure, the plurality of lead screws includes four lead screws arranged in a generally square cross-sectional configuration.

In another aspect of the present disclosure, at least one guide dowel extends between the first and second base plates and is coupled with at least one of the collars to inhibit rotation of the at least one collar. In such aspects, each collar may include at least one C-shaped channel wherein each collar is configured to receive a portion of the at least one guide dowel therein to inhibit rotation of each collar.

In still another aspect of the present disclosure, each collar defines a ferrule configured for receipt of the corresponding threaded nipple in engagement therewith.

In yet another aspect of the present disclosure, the articulation assembly further includes a plurality of proximal gear assemblies configured to drive rotation of the plurality of lead screws. In such aspects, a coupling gear may couple two of the proximal gear assemblies such that two of the lead screws are driven by a single input. In aspects, engagement of the coupling gear(s) locks in the pre-tension of articulation cable(s).

A robotic surgical instrument provided in accordance with the present disclosure (but not explicitly claimed) includes a housing, a shaft extending distally from the housing in fixed longitudinal position relative to the housing, a fixed plate disposed within the housing in fixed longitudinal position relative to the shaft and the housing, and a actuation assembly disposed within the housing. A portion of the actuation assembly includes first and second base plates, a plurality of lead screws extending distally from the first base plate to the second base plate, a collar disposed in threaded engagement about each of the lead screws, and an articulation cable coupled to each of the collars. Each lead screw is rotatable but longitudinally fixed relative to the first and second base plates. Each collar is configured to translate longitudinally along a corresponding one of the lead screws in response to rotation of the corresponding lead screw. Translation of one of the collars tensions or un-tensions a corresponding one of the articulation cables. At least one biasing member is disposed between the second base plate and the fixed plate to bias the portion of the actuation assembly proximally relative to the housing and the shaft, thereby biasing the articulation cables proximally to apply a pre-tension thereto.

The robotic surgical instrument may include any of the aspects detailed above or otherwise herein.

The at least one biasing member may be disposed about the shaft. Alternatively or additionally, the at least one biasing member is centered relative to the plurality of lead screws to substantially equally pre-tension the articulation cables. The at least one biasing member may be a coil compression spring.

Another articulation assembly for a robotic surgical instrument provided in accordance with the present disclosure (but not explicitly claimed) includes first and second base plates, a plurality of lead screws extending distally from the first base plate to the second base plate, a collar disposed in threaded engagement about each of the lead screws, an articulation cable coupled to each of the collars, and a biasing member disposed about each of the lead screws between the corresponding collar and the second base plate. Each lead screw is rotatable but longitudinally fixed relative to the first and second base plates. Each collar is configured to translate longitudinally along a corresponding one of the lead screws in response to rotation of the corresponding lead screw. Each articulation cable is coupled to one of the collars such that translation of one of the collars tensions or un-tensions a corresponding one of the articulation cables. Each biasing member is configured to bias the corresponding collar proximally relative to the second base plate, thereby biasing the articulation cables proximally to apply a pre-tension thereto.

The articulation assembly may include any of the aspects detailed above or otherwise herein.

The biasing members may be similar to one another such that the articulation cables are substantially equally pre-tensioned.

The biasing members may be coil compression springs.

Various aspects and features of the present disclosure are described hereinbelow with reference to the drawings wherein like numerals designate identical or corresponding elements in each of the several views.

Referring to <FIG>, a surgical instrument <NUM> provided in accordance with the present disclosure generally includes a housing (not shown) a shaft <NUM> extending distally from the housing, an end effector assembly <NUM> extending distally from shaft <NUM>, and an actuation assembly <NUM> disposed within the housing and operably associated with end effector assembly <NUM>. Instrument <NUM> is detailed herein as an articulating electrosurgical forceps configured for use with a robotic surgical system, e.g., robotic surgical system <NUM> (<FIG>). However, the aspects and features of instrument <NUM> provided in accordance with the present disclosure, detailed below, are equally applicable for use with other suitable surgical instruments and/or in other suitable surgical systems.

Shaft <NUM> of instrument <NUM> includes a proximal segment <NUM>, a distal segment <NUM>, and an articulating section <NUM> disposed between the proximal and distal segments <NUM>, <NUM>, respectively. Articulating section <NUM> includes one or more articulating components <NUM>, e.g., links, joints, etc. A plurality of articulation cables <NUM> (see also <FIG>), e.g., four (<NUM>) articulation cables, or other suitable actuators, extend through articulating section <NUM>. More specifically, articulation cables <NUM> are operably coupled to distal segment <NUM> of shaft <NUM> at the distal ends thereof and extend proximally from distal segment <NUM> of shaft <NUM>, through articulating section <NUM> of shaft <NUM> and proximal segment <NUM> of shaft <NUM>, and into the housing, wherein articulation cables <NUM> operably couple with articulation sub-assembly <NUM> of actuation assembly <NUM> to enable selective articulation of distal segment <NUM> (and, thus end effector assembly <NUM>) relative to proximal segment <NUM> and the housing, e.g., about at least two axes of articulation (yaw and pitch articulation, for example). Articulation cables <NUM> are arranged to define a generally square configuration, although other suitable configurations are also contemplated.

With respect to articulation of end effector assembly <NUM> relative to proximal segment <NUM> of shaft <NUM>, actuation of articulation cables <NUM> is effected in pairs. More specifically, in order to pitch end effector assembly <NUM>, the upper pair of articulation cables <NUM> are actuated in a similar manner while the lower pair of articulation cables <NUM> are actuated in a similar manner relative to one another but an opposite manner relative to the upper pair of articulation cables <NUM> (see also <FIG>). With respect to yaw articulation, the right pair of articulation cables <NUM> are actuated in a similar manner while the left pair of articulation cables <NUM> are actuated in a similar manner relative to one another but an opposite manner relative to the right pair of articulation cables <NUM> (see also <FIG>).

Continuing with reference to <FIG>, end effector assembly <NUM> includes first and second jaw members <NUM>, <NUM>, respectively. Each jaw member <NUM>, <NUM> includes a proximal flange portion 43a, 45a and a distal body portion 43b, 45b, respectively. Distal body portions 43b, 45b define opposed tissue-contacting surfaces <NUM>, <NUM>, respectively. Proximal flange portions 43a, 45a are pivotably coupled to one another about a pivot <NUM> and are operably coupled to one another via a cam-slot assembly <NUM> including a cam pin slidably received within cam slots defined within the proximal flange portion 43a, 45a of at least one of the jaw members <NUM>, <NUM>, respectively, to enable pivoting of jaw member <NUM> relative to jaw member <NUM> and distal segment <NUM> of shaft <NUM> between a spaced-apart position (e.g., an open position of end effector assembly <NUM>) and an approximated position (e.g., a closed position of end effector assembly <NUM>) for grasping tissue between tissue-contacting surfaces <NUM>, <NUM>. As an alternative to this unilateral configuration, a bilateral configuration may be provided whereby both jaw members <NUM>, <NUM> are pivotable relative to one another and distal segment <NUM> of shaft <NUM>.

Longitudinally-extending knife channels <NUM> (only knife channel <NUM> of jaw member <NUM> is illustrated; the knife channel of jaw member <NUM> is similarly configured) may be defined through tissue-contacting surfaces <NUM>, <NUM>, respectively, of jaw members <NUM>, <NUM>. In such configurations, a knife assembly (not shown) including a knife tube (not shown) extending from the housing through shaft <NUM> to end effector assembly <NUM> and a knife blade (not shown) disposed within end effector assembly <NUM> between jaw members <NUM>, <NUM> are provided to enable cutting of tissue grasped between tissue-contacting surfaces <NUM>, <NUM> of jaw members <NUM>, <NUM>, respectively. The knife tube is operably coupled to a knife drive sub-assembly (not shown) of actuation assembly <NUM> at a proximal end thereof to enable selective actuation to, in turn, reciprocate the knife blade between jaw members <NUM>, <NUM> to cut tissue grasped between tissue-contacting surfaces <NUM>, <NUM>. Although described herein as sub-assemblies of actuation assembly <NUM>, the articulation sub-assembly <NUM>, the knife drive sub-assembly, and the jaw drive sub-assembly (not shown; detailed below) of actuation assembly <NUM> are operably independent of one another. That is, actuation assembly <NUM> generally refers to the various operable sub-assemblies and/or components packaged at least partially within the housing of instrument <NUM>, whether or not they are operably and/or physically linked to one another.

Referring still to <FIG>, a drive rod <NUM> is operably coupled to cam-slot assembly <NUM> of end effector assembly <NUM>, e.g., engaged with the cam pin thereof, such that longitudinal actuation of drive rod <NUM> pivots jaw member <NUM> relative to jaw member <NUM> between the spaced-apart and approximated positions. More specifically, urging drive rod <NUM> proximally pivots jaw member <NUM> relative to jaw member <NUM> towards the approximated position while urging drive rod <NUM> distally pivots jaw member <NUM> relative to jaw member <NUM> towards the spaced-apart position. However, other suitable mechanisms and/or configurations for pivoting jaw member <NUM> relative to jaw member <NUM> between the spaced-apart and approximated positions in response to selective actuation of drive rod <NUM> are also contemplated. Drive rod <NUM> extends proximally from end effector assembly <NUM> through shaft <NUM> and into the housing wherein drive rod <NUM> is operably coupled with a jaw drive sub-assembly (not shown) of actuation assembly <NUM> to enable selective actuation of end effector assembly <NUM> to grasp tissue therebetween and apply a closure force within an appropriate jaw closure force range.

Tissue-contacting surfaces <NUM>, <NUM> of jaw members <NUM>, <NUM>, respectively, are at least partially formed from an electrically conductive material and are energizable to different potentials to enable the conduction of electrical energy through tissue grasped therebetween, although tissue-contacting surfaces <NUM>, <NUM> may alternatively be configured to supply any suitable energy, e.g., thermal, microwave, light, ultrasonic, ultrasound, etc., through tissue grasped therebetween for energy-based tissue treatment. Instrument <NUM> defines a conductive pathway (not shown) through the housing and shaft <NUM> to end effector assembly <NUM> that may include lead wires, contacts, and/or electrically-conductive components to enable electrical connection of tissue-contacting surfaces <NUM>, <NUM> of jaw members <NUM>, <NUM>, respectively, to an energy source (not shown), e.g., an electrosurgical generator, for supplying energy to tissue-contacting surfaces <NUM>, <NUM> to treat, e.g., seal, tissue grasped between tissue-contacting surfaces <NUM>, <NUM>.

Actuation assembly <NUM> is disposed within the housing and, as noted above, includes an articulation sub-assembly <NUM>, a knife drive sub-assembly (not shown), and a jaw drive sub-assembly (not shown). Articulation sub-assembly <NUM>, as detailed below, is operably coupled between first and second rotational inputs, respectively, provided to actuation assembly <NUM>, and articulation cables <NUM> such that, upon receipt of appropriate inputs into the first and/or second rotational inputs, articulation sub-assembly <NUM> manipulates articulation cables <NUM> to articulate end effector assembly <NUM> in a desired direction, e.g., to pitch and/or yaw end effector assembly <NUM>.

The knife drive sub-assembly is operably coupled to a third rotational input provided to actuation assembly <NUM> such that, upon receipt of appropriate input into the third rotational input, the knife drive sub-assembly manipulates the knife tube to reciprocate the knife blade between jaw members <NUM>, <NUM> to cut tissue grasped between tissue-contacting surfaces <NUM>, <NUM>.

The jaw drive sub-assembly is operably coupled between a fourth rotational input provided to actuation assembly <NUM> and drive rod <NUM> such that, upon receipt of appropriate input into the fourth rotational input, the jaw drive sub-assembly pivots jaw members <NUM>, <NUM> between the spaced-apart and approximated positions to grasp tissue therebetween and apply a closure force within an appropriate closure force range.

Actuation assembly <NUM> is configured to operably interface with a robotic surgical system <NUM> (<FIG>) when instrument <NUM> is mounted on robotic surgical system <NUM> (<FIG>), to enable robotic operation of actuation assembly <NUM> to provide the above-detailed functionality, e.g., to provide the rotational inputs to actuation assembly <NUM>. However, it is also contemplated that actuation assembly <NUM> be configured to interface with any other suitable surgical system, e.g., a manual surgical handle, a powered surgical handle, etc. For the purposes herein, robotic surgical system <NUM> (<FIG>) is generally described.

Turning to <FIG>, robotic surgical system <NUM> is configured for use in accordance with the present disclosure. Aspects and features of robotic surgical system <NUM> not germane to the understanding of the present disclosure are omitted to avoid obscuring the aspects and features of the present disclosure in unnecessary detail.

Robotic surgical system <NUM> generally includes a plurality of robot arms <NUM>, <NUM>; a control device <NUM>; and an operating console <NUM> coupled with control device <NUM>. Operating console <NUM> may include a display device <NUM>, which may be set up in particular to display three-dimensional images; and manual input devices <NUM>, <NUM>, by means of which a person, e.g., a surgeon, may be able to telemanipulate robot arms <NUM>, <NUM> in a first operating mode. Robotic surgical system <NUM> may be configured for use on a patient <NUM> lying on a patient table <NUM> to be treated in a minimally invasive manner. Robotic surgical system <NUM> may further include a database <NUM>, in particular coupled to control device <NUM>, in which are stored, for example, pre-operative data from patient <NUM> and/or anatomical atlases.

Each of the robot arms <NUM>, <NUM> may include a plurality of members, which are connected through joints, and mounted device which may be, for example, a surgical tool "ST. " One or more of the surgical tools "ST" may be instrument <NUM> (<FIG>), thus providing such functionality on a robotic surgical system <NUM>.

Robot arms <NUM>, <NUM> may be driven by electric drives, e.g., motors, connected to control device <NUM>. Control device <NUM>, e.g., a computer, may be configured to activate the motors, in particular by means of a computer program, in such a way that robot arms <NUM>, <NUM>, and, thus, their mounted surgical tools "ST" execute a desired movement and/or function according to a corresponding input from manual input devices <NUM>, <NUM>, respectively. Control device <NUM> may also be configured in such a way that it regulates the movement of robot arms <NUM>, <NUM> and/or of the motors.

With reference to <FIG>, <FIG>, and <FIG>, articulation sub-assembly <NUM> of actuation assembly <NUM> is shown generally including a proximal base assembly <NUM>, an intermediate base assembly <NUM>, a distal base assembly <NUM>, four proximal gear assemblies <NUM>, <NUM>, <NUM>, <NUM>, two coupling gears <NUM>, <NUM> four distal gear assemblies configured as lead screw assemblies <NUM>, <NUM>, <NUM>, <NUM> (although other suitable distal gear assemblies are also contemplated), and four guide dowels <NUM>. As an alternative or in addition to coupling gears <NUM>, <NUM>, belts may be utilized to provide the coupling. Likewise, other gearing components detailed herein may be replaced or supplemented with the use of belts instead of directly meshed gears, without departing from the present disclosure. Further, multiple gears (and/or belts) may be provided in place of single gears (and/or belts) to provide a desired amplification or attenuation effect.

Each of the proximal, intermediate, and distal base assemblies <NUM>, <NUM>, <NUM>, respectively, includes a base plate <NUM>, <NUM>, <NUM> defining four apertures <NUM>, <NUM>, <NUM> arranged in a generally square configuration. Bushings <NUM>, <NUM>, <NUM> are engaged within the apertures <NUM>, <NUM>, <NUM> of each of proximal, intermediate, and distal base assemblies <NUM>, <NUM>, <NUM>, respectively.

Each proximal gear assembly <NUM>, <NUM>, <NUM>, <NUM> includes a gear shaft <NUM> defining an input <NUM> at a proximal end thereof. However, only two inputs <NUM> are needed and, indeed, only two are utilized, as detailed below. Thus, in some configurations, only two of the proximal gear assemblies, e.g., proximal gear assemblies <NUM>, <NUM>, include inputs <NUM> while the other two proximal gear assemblies, e.g., proximal gear assemblies <NUM>, <NUM>, do not. Each proximal gear assembly <NUM>, <NUM>, <NUM>, <NUM> further includes an output <NUM> at a distal end thereof. A spur gear <NUM> is mounted on the respective gear shaft <NUM> of each proximal gear assembly <NUM>, <NUM>, <NUM>, <NUM>. Proximal gear assemblies <NUM>, <NUM>, <NUM>, <NUM> are arranged to define a generally square configuration such that the spur gear <NUM> of each proximal gear assembly <NUM>, <NUM>, <NUM>, <NUM>, includes two adjacent spur gears <NUM>, e.g., a vertically-adjacent spur gear <NUM> and a horizontally-adjacent spur gear <NUM>, and a diagonally-opposed spur gear <NUM>. One pair of diagonally-opposed spur gears <NUM>, e.g., spur gears <NUM> of proximal gear assemblies <NUM>, <NUM>, are longitudinally offset relative to the other pair of diagonally-opposed spur gears <NUM>, e.g., spur gears <NUM> of proximal gear assemblies <NUM>, <NUM>. More specifically, spur gears <NUM> of proximal gear assemblies <NUM>, <NUM> are more-distally disposed as compared to spur gears <NUM> of proximal gear assemblies <NUM>, <NUM>.

The utilized inputs <NUM> (or inputs <NUM> provided, where only two are provided), e.g., the inputs <NUM> of proximal gear assemblies <NUM>, <NUM>, extend proximally into a corresponding bushing <NUM> disposed within an aperture <NUM> of base plate <NUM> of proximal base assembly <NUM>. In this manner, the two inputs <NUM> are positioned at a proximal end of articulation sub-assembly <NUM> to receive two rotational inputs for articulation, e.g., from a robotic surgical system <NUM> (<FIG>). The output <NUM> of each proximal gear assembly <NUM>, <NUM>, <NUM>, <NUM> extends distally into a corresponding bushing <NUM> disposed within an aperture <NUM> of base plate <NUM> of intermediate base assembly <NUM>. As detailed below, this enables the output <NUM> of each proximal gear assembly <NUM>, <NUM>, <NUM>, <NUM> to provide a rotational output to a corresponding lead screw assembly <NUM>, <NUM>, <NUM>, <NUM>, respectively.

Continuing with reference to <FIG>, <FIG>, and <FIG>, the two coupling gears <NUM>, <NUM> operably couple the spur gears <NUM> of each diagonally-opposed pair of spur gears <NUM>. More specifically, the more-distal coupling gear <NUM> is disposed in meshed engagement with the more-distally disposed spur gears <NUM> of proximal gear assemblies <NUM>, <NUM>, while the more-proximal coupling gear <NUM> is disposed in meshed engagement with the more-proximally disposed spur gears <NUM> of proximal gear assemblies <NUM>, <NUM>.

As a result of the above-detailed configuration, for example, a rotational input provided to input <NUM> of proximal gear assembly <NUM> rotates output <NUM> and spur gear <NUM> of proximal gear assembly <NUM> in a first direction to, in turn, rotate coupling gear <NUM> in a second, opposite direction which, in turn, rotates spur gear <NUM> and output <NUM> of proximal gear assembly <NUM> in the first direction. Further, as another example, a rotational input provided to input <NUM> of proximal gear assembly <NUM> rotates output <NUM> and spur gear <NUM> of proximal gear assembly <NUM> in a first direction to, in turn, rotate coupling gear <NUM> in a second, opposite direction which, in turn, rotates spur gear <NUM> and output <NUM> of proximal gear assembly <NUM> in the first direction. Thus, only two rotational inputs are required to provide a rotational output at the output <NUM> of each proximal gear assembly <NUM>, <NUM>, <NUM>, <NUM>: one to the input <NUM> of proximal gear assembly <NUM> or proximal gear assembly <NUM>, and the other to the input <NUM> of proximal gear assembly <NUM> or proximal gear assembly <NUM>. As noted above, only two inputs <NUM> thus need be provided, e.g., input <NUM> of proximal gear assembly <NUM> and input <NUM> of proximal gear assembly <NUM>.

Each lead screw assembly <NUM>, <NUM>, <NUM>, <NUM> includes a lead screw <NUM> defining a proximal input end <NUM> and a distal dock end <NUM>. Each lead screw assembly <NUM>, <NUM>, <NUM>, <NUM> further includes a collar <NUM> disposed in threaded engagement about the corresponding lead screw <NUM> such that rotation of the lead screw <NUM> translates the corresponding collar <NUM> longitudinally therealong. The proximal input end <NUM> of the lead screw <NUM> of each lead screw assembly <NUM>, <NUM>, <NUM>, <NUM> extends proximally into a corresponding bushing <NUM> disposed within an aperture <NUM> of base plate <NUM> of intermediate base assembly <NUM> wherein the proximal input end <NUM> is operably coupled with the output <NUM> of a corresponding proximal gear assembly <NUM>, <NUM>, <NUM>, <NUM> such that rotation of outputs <NUM> effect corresponding rotation of lead screws <NUM>. The distal dock end <NUM> of the lead screw <NUM> of each lead screw assembly <NUM>, <NUM>, <NUM>, <NUM> extend distally into and is rotationally seated within a corresponding bushing <NUM> disposed within an aperture <NUM> of base plate <NUM> of distal base assembly <NUM>.

Lead screw assemblies <NUM>, <NUM>, <NUM>, <NUM>, similarly as with proximal gear assemblies <NUM>, <NUM>, <NUM>, <NUM>, are arranged to define a generally square configuration such that the lead screw <NUM> of each lead screw assembly <NUM>, <NUM>, <NUM>, <NUM>, includes two adjacent lead screws <NUM>, e.g., a vertically-adjacent lead screw <NUM> and a horizontally-adjacent lead screw <NUM>, and a diagonally-opposed lead screw <NUM>. The lead screws <NUM> of each diagonally-opposed pair of lead screws <NUM> define opposite thread-pitch directions. For example, lead screw <NUM> of lead screw assembly <NUM> may define a right-handed thread-pitch while the diagonally-opposite lead screw <NUM> of lead screw assembly <NUM> defines a left-handed thread-pitch. Similarly, lead screw <NUM> of lead screw assembly <NUM> may define a right-handed thread-pitch while the diagonally-opposite lead screw <NUM> of lead screw assembly <NUM> defines a left-handed thread-pitch.

As noted above, each collar <NUM> is operably threadingly engaged about a corresponding lead screw <NUM> such that rotation of the lead screw <NUM> translates the corresponding collar <NUM> longitudinally therealong. Each collar <NUM> includes a ferrule <NUM> configured to engage a proximal end portion of one of the articulation cables <NUM> (see <FIG>), e.g., via a crimped hook-slot engagement or other suitable engagement (mechanical fastening, adhesion, welding, etc.). Thus, distal translation of a collar <NUM> slackens the corresponding articulation cable <NUM> by pushing the corresponding articulation cable <NUM> in a distal direction, while proximal translation of a collar <NUM> tensions the corresponding articulation cable <NUM> by pulling the corresponding articulation cable <NUM> in a proximal direction.

Referring to <FIG>, and with initial reference to <FIG>, as noted above, each articulation cable <NUM> may define or include engaged thereto a J-hook end portion 39a configured for receipt with the ferrule <NUM> (<FIG>) of the corresponding collar <NUM> (<FIG>). Other suitable end configurations to facilitate engagement within the ferrule <NUM> (<FIG>) of the corresponding collar <NUM> (<FIG>) are also contemplated. For example: as shown in <FIG>, each articulation cable <NUM> may define or include engaged thereto an L-hook end portion 39b; each articulation cable <NUM> may define or include engaged thereto a pan head end portion 39c as shown in <FIG>; as shown in <FIG>, each articulation cable <NUM> may define or include engaged thereto a spoke end portion 39d; a cap 39e-<NUM> or cap with barrel 39e-<NUM> may be crimped or otherwise engaged about the end portion of each articulation cable <NUM> as shown in <FIG>, respectively; as shown in <FIG>, a donut 39f-<NUM> may be engaged, e.g., welded, about a tube 39f-<NUM> defined by or engaged to the end portion of each articulation cable <NUM>; or, with reference to FIGS. <NUM>-<NUM> through <NUM>-<NUM>, and in accordance with the present invention, the end portion of each articulation cable <NUM> defines or includes engaged thereto a rod defining external threading <NUM>-<NUM> configured for receipt within a threaded bore <NUM>-<NUM> of a tension nipple <NUM>-<NUM>.

With respect to the configuration illustrated in FIGS. <NUM>-<NUM> through <NUM>-<NUM>, the threaded engagement between each articulation cable <NUM> and the corresponding tension nipple <NUM>-<NUM> not only engages each articulation cable <NUM> with the ferrule <NUM> (<FIG>) of the corresponding collar <NUM> (<FIG>), but also enables pre-tensioning of each articulation cable <NUM> to a desired pre-tension or a pre-tension within a desired pre-tension range. More specifically, as illustrated in <FIG>, the tension nipple <NUM>-<NUM> may be threaded further onto the external threading <NUM>-<NUM> and, since the tension nipple <NUM>-<NUM> is engaged with the ferrule <NUM> (<FIG>) of the corresponding collar <NUM> (<FIG>), this further threading of the tension nipple <NUM>-<NUM> pulls the end portion of the corresponding articulation cable <NUM> proximally relative to the corresponding collar <NUM> (<FIG>), thereby increasing the pre-tension on the articulation cable <NUM>. Accordingly, each of the articulation cables <NUM> may be pre-tensioned in this manner to a desired pre-tension or a pre-tension within a desired pre-tension range. Various other pre-tensioning mechanism and methods are detailed below.

Referring again to <FIG>, <FIG>, and <FIG>, the four guide dowels <NUM> are engaged and extend between intermediate and distal base assemblies <NUM>, <NUM>, respectively, and are arranged in a generally square configuration. Each guide dowel <NUM> extends through a sleeve <NUM> of a collar <NUM> of a corresponding lead screw assembly <NUM>, <NUM>, <NUM>, <NUM>. Guide dowels <NUM> guide translation of collars <NUM> along lead screws <NUM> and inhibit rotation of collars <NUM> relative to lead screws <NUM>.

With reference to <FIG>, another configuration of a collar <NUM> is shown similar to collars <NUM> (<FIG>, <FIG>, and <FIG>) except that, rather than each collar defining a sleeve for receipt of a guide dowel <NUM>, each collar <NUM> includes a pair of C-shaped channels <NUM> disposed at substantially right angles relative to one another. Each C-shaped channel <NUM> is configured for receipt of one of the guide dowels <NUM> partially therein. Thus, each of the four guide dowels <NUM> is received within a C-shaped channel <NUM> of two different collars <NUM>. While receipt of a dowel <NUM> within one C-shaped channel <NUM> may be insufficient to prevent rotation, e.g., in response to high rotational forces dislodging the dowel <NUM> from the open mouth of the C-shaped channel <NUM>, providing a pair of C-shaped channels <NUM> disposed at substantially right angles relative to one another with each coupled to a dowel <NUM> sufficiently inhibits rotation of collars <NUM>. Collars <NUM> may also include open ferrules <NUM> for receipt of the end portions of articulation cables <NUM>, rather than fully enclosed ferrules as with collars <NUM> (<FIG>, <FIG>, and <FIG>).

Turning back to <FIG>, <FIG>, and <FIG>, in order to pitch end effector assembly <NUM>, collars <NUM> of lead screw assemblies <NUM>, <NUM> are translated in a similar manner to actuate the upper pair of articulation cables <NUM> in a similar manner while collars <NUM> of lead screw assemblies <NUM>, <NUM> are translated similarly to one another but opposite of the collars <NUM> of lead screw assemblies <NUM>, <NUM> such that the lower pair of articulation cables <NUM> are actuated in a similar manner relative to one another but an opposite manner relative to the upper pair of articulation cables <NUM>. With respect to yaw articulation of end effector assembly <NUM>, collars <NUM> of lead screw assemblies <NUM>, <NUM> are translated in a similar manner to actuate the right pair of articulation cables <NUM> in a similar manner while collars <NUM> of lead screw assemblies <NUM>, <NUM> are translated similarly to one another but opposite of the collars <NUM> of lead screw assemblies <NUM>, <NUM> such that the left pair of articulation cables <NUM> are actuated in a similar manner relative to one another but an opposite manner relative to the right pair of articulation cables <NUM>.

Thus, as demonstrated above, the collars <NUM> of opposing diagonal pairs of collars <NUM> always move in opposite directions relative to one another to effect articulation, regardless of whether of pitch and/or yaw articulation is desired and regardless of the direction of articulation, e.g., up pitch, down pitch, left yaw, right yaw, or combinations thereof. As also detailed above, a rotational input provided to input <NUM> of proximal gear assembly <NUM> or proximal gear assembly <NUM> provides a similar rotational output at the output <NUM> of both proximal gear assembly <NUM> and proximal gear assembly <NUM> due to the coupling thereof via coupling gear <NUM> and, thus, lead screw assemblies <NUM>, <NUM> receive similar inputs from proximal gear assemblies <NUM>, <NUM>, respectively. However, since the thread-pitch of the lead screws <NUM> of lead screw assemblies <NUM>, <NUM> are opposite one another, the similar inputs provided thereto effect opposite translation of the collars <NUM> thereof. Likewise, a rotational input provided to input <NUM> of proximal gear assembly <NUM> or proximal gear assembly <NUM> provides a similar rotational output at both outputs <NUM> due to the coupling thereof via coupling gear <NUM> and, thus, lead screw assemblies <NUM>, <NUM> receive similar inputs from proximal gear assemblies <NUM>, <NUM>, respectively, to, in turn, effect opposite translation of the collars <NUM> thereof. Thus, by controlling the directions of two rotational inputs (one to the input <NUM> of proximal gear assembly <NUM> or proximal gear assembly <NUM>, and the other to the input <NUM> of proximal gear assembly <NUM> or proximal gear assembly <NUM>), pitch and/or yaw articulation in any suitable direction may be achieved.

Pre-tensioning articulation cables <NUM> (<FIG>) facilitates accurate articulation of end effector assembly <NUM> (<FIG>). As detailed above, tension nipples <NUM>-<NUM> ( FIGS. <NUM>-<NUM> through <NUM>-<NUM>) may be utilized to pre-tension articulation cables <NUM> (<FIG>). Alternatively, with reference to <FIG>, in conjunction with <FIG>, a fixture <NUM> may be utilized to facilitate pre-tensioning of articulation cables <NUM> (<FIG>) prior to engagement of coupling gears <NUM>, <NUM> (<FIG>) within articulation sub-assembly <NUM> of actuation assembly <NUM>. Fixture <NUM> includes a base <NUM>, a pair of tensioning arms <NUM> and proximal and distal support plates <NUM>, <NUM>. Fixture <NUM> may further include or enable operable coupling with one or more force gauges <NUM> to provide feedback, e.g., input load data, as to the pre-tension on articulation cables <NUM>. Where multiple force gauges <NUM> are provided, each force gauge <NUM> may provide independent feedback as to the pre-tension on one or more articulation cables <NUM>. For example, as illustrated in <FIG>, two force gauges <NUM> may be included, each providing independent feedback from one of the tensioning arms <NUM>.

Proximal and distal support plates <NUM>, <NUM> are configured to retain articulation sub-assembly <NUM> of actuation assembly <NUM> in substantially fixed position although, in some configurations, only proximal support plate <NUM> is provided. Tensioning arms <NUM> are configured to engage an opposing diagonal pair of collars <NUM>. Tensioning arms <NUM> are coupled to one or more drives <NUM>, e.g., gear sets, motors, pulleys, slides, etc., independently or commonly, to enable selective translation of tensioning arms <NUM> proximally, e.g., manually or automatically. Proximal movement of tensioning arms <NUM>, in turn, moves the opposing diagonal pair of collars <NUM> proximally to tension the corresponding articulation cables <NUM> to a desired pre-tension or pre-tension within a desired pre-tension range. The pre-tensions are verified using the outputs of the force gauges <NUM>.

The above-detailed pre-tensioning may first be performed, for example, by inserting articulation sub-assembly <NUM> of actuation assembly <NUM> into fixture <NUM> such that the collars <NUM> associated with lead screw assemblies <NUM>, <NUM> (<FIG>) are engaged with tensioning arms <NUM>. In this manner, the articulation cables <NUM> associated with lead screw assemblies <NUM>, <NUM> are pre-tensioned. Once this pre-tension has been achieved, coupling gear <NUM> (<FIG>) is inserted into meshed engagement with spur gears <NUM> (<FIG>) of proximal gear assemblies <NUM>, <NUM> (<FIG>) such that the articulation cables <NUM> associated with lead screw assemblies <NUM>, <NUM> are maintained in pre-tension. Alternatively, lead screw assemblies <NUM>, <NUM> may otherwise be secured to maintain the pre-tension.

Thereafter, articulation sub-assembly <NUM> of actuation assembly <NUM> may be removed, rotated, and re-inserted into fixture <NUM> such that the collars <NUM> associated with lead screw assemblies <NUM>, <NUM> (<FIG>) are engaged with tensioning arms <NUM>. In this manner, the articulation cables <NUM> associated with lead screw assemblies <NUM>, <NUM> are pre-tensioned. Once this pre-tension has been achieved, coupling gear <NUM> (<FIG>) is inserted into meshed engagement with spur gears <NUM> (<FIG>) of proximal gear assemblies <NUM>, <NUM> (<FIG>) such that the articulation cables <NUM> associated with lead screw assemblies <NUM>, <NUM> are maintained in pre-tension. Alternatively, lead screw assemblies <NUM>, <NUM> may otherwise be secured to maintain the pre-tension. It is also contemplated that the above order be reversed or that other suitable pairs of leas screw assemblies, <NUM>-<NUM> be pre-tensioned in the above-detailed manner.

Referring to <FIG>, in conjunction with <FIG>, and initially to <FIG>, <FIG>, in order to facilitate pre-tensioning of articulation cables <NUM> (<FIG>) lead screws <NUM> (individually, in pairs, or collectively) may be rotated to drive collars <NUM> proximally, thereby tensioning articulation cables <NUM>. This may be accomplished, for example via defining engagable patterns <NUM> as recesses within end faces <NUM> of distal dock ends <NUM> of lead screws <NUM>. As noted above, distal base assembly <NUM> includes base plate <NUM> defining four apertures <NUM> (<FIG>) arranged in a generally square configuration. Bushings <NUM>, e.g., ball bearings, are engaged within the apertures <NUM> defined within base plate <NUM> and the distal dock ends <NUM> of the lead screws <NUM> are engaged within bushings <NUM> thus rotationally seating lead screws <NUM> within base plate <NUM> of distal base assembly <NUM>. As illustrated in <FIG>, the engagable patterns <NUM> defined within end faces <NUM> may be similar to one another and may be, for example, hexagonal recesses, although other geometric or other suitable engagable patterns <NUM> are also contemplated. The hexagonal recesses are configured to receive a hexagonal driver or other suitable driver (not shown) to enable rotational driving of lead screws <NUM>. Lead screws <NUM>, more specifically, are driven to rotate to thereby translate drive collars <NUM> proximally therealong. This proximal translation of drive collars <NUM> pre-tensions the articulation cables <NUM>.

Pre-tensioning of the articulation cables <NUM> associated with a first pair of diagonally-opposed lead screws <NUM>, e.g., the lead screws of lead screw assemblies <NUM>, <NUM> (<FIG>), may be accomplished prior to engagement of coupling gear <NUM> (<FIG>) therebetween. Once the pre-tension has been achieved, coupling gear <NUM> is inserted into position such that the articulation cables <NUM> associated with lead screw assemblies <NUM>, <NUM> are maintained in pre-tension. Thereafter or therebefore, the articulation cables <NUM> associated with the other pair of diagonally-opposed lead screws <NUM>, e.g., the lead screws <NUM> of lead screw assemblies <NUM>, <NUM> (<FIG>), are pre-tensioned in a similar manner and coupling gear <NUM> (<FIG>) is engaged therebetween to maintained the pre-tension.

With reference to <FIG>, as opposed to geometric shapes and/or similar engagable patterns, other configurations of engagable patterns <NUM> may be defined as recesses within the end faces <NUM> of lead screws <NUM> (<FIG>). For example, engagable patterns <NUM> may include similar or different aperture configurations configured to receive multi-pin drivers (not shown) to enable rotational driving of the lead screws <NUM> (<FIG>), e.g., two-pin, three-pin, four-pin, and five-pin drivers configured for engagement within the two-aperture, three-aperture, four-aperture, and five-aperture engagable patterns <NUM>, respectively. By providing engagable patterns <NUM> for the different lead screws <NUM> (<FIG>), identification of the lead screws <NUM> (<FIG>) and, thus, their appropriate position in the articulation sub-assembly <NUM> of actuation assembly <NUM> (see <FIG>) during assembly can be readily achieved. As an alternative to requiring different drivers, it is contemplated that a universal driver (not shown) configured to engage each of the engagable patterns <NUM> (or any of the other engagable patterns detailed herein) may be utilized.

<FIG> illustrates other configurations of engagable patterns <NUM> defined as recesses within the end faces <NUM> of lead screws <NUM> (<FIG>), e.g., various different geometric patterns such as a square (or other quadrilateral), hexagon, triangle, and/or cross.

Turning to <FIG>, one or more springs may be utilized to pre-tension articulation cables <NUM>. More specifically, rather than longitudinally securing at least base plate <NUM> and lead screws <NUM> of articulation sub-assembly <NUM> of actuation assembly <NUM> within and relative to the outer housing <NUM> that houses actuation assembly <NUM>, at least a portion of articulation sub-assembly <NUM> of actuation assembly <NUM>, e.g., at least base plate <NUM> and lead screws <NUM>, may float, allowing longitudinal translation within and relative to outer housing <NUM> and, thus, relative to shaft <NUM> and the distal end portions of articulation cables <NUM>. In some configurations, a fixed distal plate <NUM> is engaged, in longitudinally fixed position about a proximal end portion of shaft <NUM> and/or to housing <NUM>. Fixed distal plate <NUM> is distally-spaced from base plate <NUM> of articulation sub-assembly <NUM> of actuation assembly <NUM>. A biasing member <NUM>, e.g., a compression coil spring, is disposed between fixed distal plate <NUM> and base plate <NUM>, and may be disposed about shaft <NUM>. Biasing member <NUM> biases base plate <NUM> proximally relative to fixed distal plate <NUM> and, thus, relative to housing <NUM>, shaft <NUM>, and articulation cables <NUM>. In this manner, the at least a portion of (or the entirety of) articulation sub-assembly <NUM> of actuation assembly <NUM> floats within housing <NUM> whereby biasing member <NUM> acts to apply and maintain a desired pre-tension or a pre-tension within a desired pre-tension range on articulation cables <NUM> by biasing base plate <NUM>, lead screws <NUM>, and collars <NUM> (and, thus, the proximal end portions of articulation cables <NUM>) proximally.

The centered location of biasing member <NUM> relative to lead screws <NUM> and, thus, relative to articulation cables <NUM> provides a substantially equally-distributed proximal force on base plate <NUM> such that a substantially equal pre-tension on each of the articulation cables <NUM> is achieved. As an alternative to a single, centered biasing member <NUM>, other suitable arrangements of one or more biasing members disposed between fixed distal plate <NUM> and base plate <NUM> may be provided that enable equal pre-tension on each of the articulation cables <NUM>.

Referring to <FIG>, in another configuration, base plate <NUM> and lead screws <NUM> are longitudinally-fixed within housing <NUM> (which houses actuation assembly <NUM>) and a biasing member <NUM>, e.g., a coil compression spring, is disposed about each lead screw <NUM> between the collar <NUM> thereof and base plate <NUM>. Biasing members <NUM> thus act to bias collars <NUM> proximally to pre-tension articulation cables <NUM>. Biasing members <NUM> are similarly configured and position such that a substantially equal proximal force is provided on each collar <NUM>, thereby applying a substantially equal pre-tension on each of the articulation cables <NUM>. As can be appreciated due to the positioning of biasing members <NUM>, as a lead screw <NUM> is driven to advance the corresponding collar <NUM> distally, the biasing member <NUM> disposed between that collar <NUM> and base plate <NUM> is compressed thereby increasing the requisite driving force, while, on the other hand, as a lead screw <NUM> is driven to retract the corresponding collar <NUM> proximally, the biasing member <NUM> disposed between that collar <NUM> and base plate <NUM> is allowed to extend further, thereby decreasing the requisite driving force. Similarly as detailed above, coupling gears <NUM>, <NUM> (<FIG>), once installed, serve to lock the pre-tension on articulation cables <NUM> applied by biasing member <NUM>.

With reference to <FIG>, in conjunction with <FIG> and <FIG>, still another configuration that facilitates pre-tensioning of the articulation cables <NUM> (<FIG>) in accordance with the present disclosure is provided. As detailed above, a spur gear <NUM> is fixedly mounted on each gear shaft <NUM> (<FIG> and <FIG>) and each gear shaft <NUM> is engaged, in fixed rotational orientation, with a corresponding lead screw <NUM> (<FIG> and <FIG>). Thus, rotation of a spur gear <NUM> drives rotation of a corresponding lead screw <NUM> to thereby translate the corresponding collar <NUM> (<FIG> and <FIG>) therealong to further tension or un-tension the corresponding articulation cable <NUM>. In some configurations, base plate <NUM> and/or base plate <NUM> define transverse cut-outs <NUM> exposing portions of the outer gear circumferences of spur gears <NUM>. More specifically, cut-outs <NUM> sufficiently expose spur gears <NUM> to enable driver gears <NUM> to be disposed in meshed engagement therewith and, upon rotation of the drive gears <NUM>, to drive rotation of the spur gears <NUM>.

The above-detailed configuration enables, prior to engagement of coupling gear <NUM> between the spur gears <NUM> of a first pair of diagonally-opposed lead screws <NUM>, those spur gears <NUM> to be engaged by drive gear(s) <NUM> and driven to rotate to thereby rotate the corresponding lead screws <NUM> to translate collars <NUM> proximally to pre-tension the corresponding articulation cables <NUM>. Once the pre-tension has been achieved, coupling gear <NUM> is inserted into position such that the articulation cables <NUM> associated with those driven lead screws <NUM> are maintained in pre-tension. The articulation cables <NUM> associated with the other pair of diagonally-opposed lead screws <NUM> are pre-tensioned in a similar manner and coupling gear <NUM> is engaged therebetween to maintained the pre-tension.

Turning to <FIG>, a housing <NUM> configured for use with surgical instrument <NUM> or other suitable robotic surgical instrument is shown. Housing <NUM> is formed form first and second housing components <NUM>, <NUM> secured to one another about their perimeters to seal off the interior volume thereof that houses actuation assembly <NUM> therein. Housing <NUM> is further configured to seal about shaft <NUM> which extends distally therefrom.

In order to seal housing <NUM>, a foam tape <NUM> is disposed on the perimeter mating surface of one of the housing components <NUM>, <NUM> and the housing components <NUM>, <NUM> are pressed together to bond and seal the housing <NUM>. The foam tape <NUM> may be double-sided to includes acrylic adhesive or other suitable adhesive on both sides of a conformable foam base to enable adhesion and sealing with housing components <NUM>, <NUM>. This configuration provides high-strength, durable permanent bonding that establishes a permanent seal against moisture and fluids such as blood, saline, water etc. Further, this configuration eliminates the need for more expensive and/or labor-intensive methods such as press-fitting, screws, snaps, ultrasonic welding, etc..

Claim 1:
An articulation assembly (<NUM>) for a robotic surgical instrument (<NUM>), comprising:
first and second base plates (<NUM>, <NUM>, <NUM>);
a plurality of lead screws (<NUM>) extending between the first and second base plates, each lead screw rotatable but longitudinally fixed relative to the first and second base plates;
a collar (<NUM>) disposed in threaded engagement about each of the lead screws, each collar configured to translate longitudinally along a corresponding one of the lead screws in response to rotation of the corresponding lead screw;
an articulation cable (<NUM>) coupled to each of the collars such that translation of one of the collars tensions or un-tensions a corresponding one of the articulation cables; and
a tensioning mechanism, wherein the tensioning mechanism includes a threaded nipple (<NUM>-<NUM>) disposed in threaded engagement about a threaded shaft (<NUM>-<NUM>) defined by or engaged with each of the articulation cables, each threaded nipple engaged with one of the collars to thereby engage each of the articulation cables with a corresponding one of the collars such that longitudinal translation of the corresponding collar pushes or pulls the corresponding articulation cable, wherein each threaded nipple is configured for further threading or unthreading about the corresponding threaded shaft to vary a pre-tension on the corresponding articulation cable.