Patent Description:
<CIT> relates to a robotic surgical tool having opposing jaws, the working element of the robotic surgical tool is made of a different material from the drive element of the robotic surgical tool. The two elements may be manufactured independently and assembled together at a later stage. The material comprising each element may thus have properties more appropriate to the function each element plays in the robotic surgical tool. For example, the metal selected to comprise the blade of a surgical scissor may be corrosion resistant and capable of being sharpened to a high degree.

<CIT> relates to a medical instrument assembly comprising an elongated shaft, a tool carried by the distal end of the elongated shaft for performing a medical procedure on a patient, a plurality of controllably bendable sections spaced along the elongated shaft and disposed proximal to the tool, a plurality of actuation elements extending within the elongated shaft for respectively actuating the controllably bendable sections, and an instrument coupler mounted to the proximal end of the elongated shaft, with the instrument coupler configured for coupling an electromechanical drive to the actuation elements.

Minimally invasive surgical (MIS) instruments are often preferred over traditional open surgical devices due to reduced post-operative recovery time and minimized scarring. Endoscopic surgery is one type of MIS procedure in which an elongate flexible shaft is introduced into the body of a patient through a natural orifice. Laparoscopic surgery is another type of MIS procedure in which one or more small incisions are formed in the abdomen of a patient and a trocar is inserted through the incision to form a pathway that provides access to the abdominal cavity. Through the trocar, a variety of instruments and surgical tools can be introduced into the abdominal cavity. The trocar also helps facilitate insufflation to elevate the abdominal wall above the organs. The instruments and tools introduced into the abdominal cavity via the trocar can be used to engage and/or treat tissue in a number of ways to achieve a diagnostic or therapeutic effect.

Various robotic systems have recently been developed to assist in MIS procedures. Robotic systems can allow for more intuitive hand movements by maintaining natural eye-hand axis. Robotic systems can also allow for more degrees of freedom in movement by including a "wrist" joint on the instrument, which creates a more natural hand-like articulation.

To facilitate operation of the wrist joint, robotic systems typically include cable driven motion systems designed to articulate (move) the instrument's end effector. Common cable driven motion system include one or more drive cables (alternately referred to as elongate members or wires) that extend through the wrist joint to aid in articulating the instrument's end effector. Some surgical tools, such as needle drivers and graspers (forceps), require large amounts of grip force and higher load capacity to properly undertake various surgical procedures. Conventional cable driven motion systems often cannot provide the sufficient grip force and load capacity required to undertake these various surgical procedures.

The invention is as defined by independent claim <NUM>. Dependent claims disclose exemplary embodiments.

The following figures are included to illustrate certain aspects of the present disclosure, and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, without departing from the scope of this disclosure.

The present disclosure is related to robotic surgery systems and, more particularly, to robotic surgical tools having a wrist joint that incorporates a power axle cable that delivers elevated force to the wrist joint and an associated end effector.

The embodiments disclosed herein describe a power axle wrist for a robotic surgical tool. The surgical tool includes a drive housing and an elongate shaft extending from the drive housing. The power axle wrist couples an end effector to the elongate shaft and includes a distal clevis having a first axle that rotatably mounts the end effector to the distal clevis, and a proximal clevis coupled to the elongate shaft and having a second axle that rotatably mounts the distal clevis to the proximal clevis. A plurality of drive cables extend between the drive housing and the end effector, and movement of the drive cables causes the end effector to articulate about a first pivot axis extending through the first axle. A power axle cable extends from the drive housing and is mounted to the distal clevis such that movement of the power axle cable correspondingly pivots the end effector about a second pivot axis at the second axle. The power axle cable is dedicated entirely to transmitting force to the distal clevis and thereby provides an elevated amount of force and loading capability for the end effector.

<FIG> is side view of an example surgical tool <NUM> that may incorporate some or all of the principles of the present disclosure. As illustrated, the surgical tool <NUM> includes an elongate shaft <NUM>, an end effector <NUM>, a wrist <NUM> (alternately referred to as a "wrist joint") that couples the end effector <NUM> to the distal end of the shaft <NUM>, and a drive housing <NUM> coupled to the proximal end of the shaft <NUM>. The surgical tool <NUM> may be designed to be releasably coupled to a robotic surgical system, and the drive housing <NUM> can include coupling features that releasably couple the surgical tool <NUM> to the robotic surgical system.

The terms "proximal" and "distal" are defined herein relative to a robotic surgical system having an interface configured to mechanically and electrically couple the surgical tool <NUM> (e.g., the housing <NUM>) to a robotic manipulator. The term "proximal" refers to the position of an element closer to the robotic manipulator and the term "distal" refers to the position of an element closer to the end effector <NUM> and thus further away from the robotic manipulator. Moreover, the use of directional terms such as above, below, upper, lower, upward, downward, left, right, and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward or upper direction being toward the top of the corresponding figure and the downward or lower direction being toward the bottom of the corresponding figure.

During use of the surgical tool <NUM>, the end effector <NUM> is configured to move (pivot) relative to the shaft <NUM> at the wrist <NUM> to position the end effector <NUM> at a desired orientation and location relative to a surgical site. The housing <NUM> includes various mechanisms designed to control operation of various features associated with the end effector <NUM> (e.g., clamping, firing, rotation, articulation, energy delivery, etc.). In at least some embodiments, the shaft <NUM>, and hence the end effector <NUM> coupled thereto, is configured to rotate about a longitudinal axis A<NUM> of the shaft <NUM>. In such embodiments, at least one of the mechanisms included in the housing <NUM> is configured to control rotational movement of the shaft <NUM> about the longitudinal axis A<NUM>.

The surgical tool <NUM> can have any of a variety of configurations capable of performing at least one surgical function. For example, the surgical tool <NUM> may include, but is not limited to, forceps, a grasper, a needle driver, scissors, an electro cautery tool, a stapler, a clip applier, a suction tool, an irrigation tool, an imaging device (e.g., an endoscope or ultrasonic probe), or any combination thereof. The surgical tool <NUM> may be configured to apply energy to tissue, such as radiofrequency (RF) energy.

The shaft <NUM> is an elongate member extending distally from the housing <NUM> and has at least one lumen extending therethrough along its axial length. The shaft <NUM> may be fixed to the housing <NUM>, but could alternatively be rotatably mounted to the housing <NUM> to allow the shaft <NUM> to rotate about the longitudinal axis A<NUM>. The shaft <NUM> may be releasably coupled to the housing <NUM>, which may allow a single housing <NUM> to be adaptable to various shafts having different end effectors.

The end effector <NUM> can have a variety of sizes, shapes, and configurations. The end effector <NUM> comprises a tissue grasper having opposing jaws <NUM>, <NUM> configured to move between open and closed positions. One or both of the jaws <NUM>, <NUM> may be configured to pivot at the wrist <NUM> to move the end effector <NUM> between the open and closed positions. However, the end effector <NUM> may have other configurations, e.g., scissors including a pair of opposed cutting blades, a babcock including a pair of opposed grasping jaws, a retractor, a hook, a spatula, needle drivers, graspers, forceps, etc..

The wrist <NUM> can have any of a variety of configurations. In general, the wrist <NUM> comprises a joint configured to allow pivoting movement of the end effector <NUM> relative to the shaft <NUM>. As discussed in more detail below, the wrist <NUM> may be characterized as a "Power Axle Wrist" capable of delivering elevated force and loading to the end effector <NUM> as compared to conventional wrist joints.

<FIG> illustrates the potential degrees of freedom in which the wrist <NUM> may be able to articulate (pivot). The degrees of freedom of the wrist <NUM> are represented by three translational variables (i.e., surge, heave, and sway), and by three rotational variables (i.e., Euler angles or roll, pitch, and yaw). The translational and rotational variables describe the position and orientation of a component of a surgical system (e.g., the end effector <NUM>) with respect to a given reference Cartesian frame. As depicted in <FIG>, "surge" refers to forward and backward translational movement, "heave" refers to translational movement up and down, and "sway" refers to translational movement left and right. With regard to the rotational terms, "roll" refers to tilting side to side, "pitch" refers to tilting forward and backward, and "yaw" refers to turning left and right.

The pivoting motion can include pitch movement about a first axis of the wrist <NUM> (e.g., X-axis), yaw movement about a second axis of the wrist <NUM> (e.g., Y-axis), and combinations thereof to allow for <NUM>° rotational movement of the end effector <NUM> about the wrist <NUM>. In other applications, the pivoting motion can be limited to movement in a single plane, e.g., only pitch movement about the first axis of the wrist <NUM> or only yaw movement about the second axis of the wrist <NUM>, such that the end effector <NUM> moves only in a single plane.

Referring again to <FIG>, the surgical tool <NUM> includes a plurality of drive cables (obscured in <FIG>) that form part of a cable driven motion system configured to effect movement (pivoting) of the end effector <NUM> relative to the shaft <NUM>. The drive cables may be referred to and otherwise characterized as cables, bands, lines, cords, wires, ropes, strings, twisted strings, elongate members, etc. The drive cables can be made from a variety of materials including, but not limited to, metal (e.g., tungsten, stainless steel, etc.) or a polymer. Example drive cables are described in <CIT> entitled "Compact Robotic Wrist," and <CIT> entitled "Hyperdexterous Surgical System".

The drive cables are operably coupled to various actuation mechanisms housed within the drive housing <NUM> and extend within the lumen of the shaft <NUM> to the wrist <NUM> where they are operably engaged with the end effector <NUM>. Selective actuation of all or a portion of the drive cables causes the end effector <NUM> (e.g., one or both of the jaws <NUM>, <NUM>) to move (pivot) relative to the shaft <NUM>. More specifically, selective actuation causes a corresponding drive cable to translate longitudinally within the lumen of the shaft <NUM> and thereby cause pivoting movement of the end effector <NUM>. In operation, one or more drive cables may translate longitudinally to cause the end effector <NUM> to articulate (e.g., both of the jaws <NUM>, <NUM> angle in a same direction), to cause the end effector <NUM> to open (e.g., one or both of the jaws <NUM>, <NUM> move away from the other), or to cause the end effector <NUM> to close (e.g., one or both of the jaws <NUM>, <NUM> move toward the other).

Actuation of the drive cables can be accomplished in a variety of ways, such as by triggering an associated actuator operably coupled to or housed within the drive housing <NUM>. Actuation applies tension to (i.e., pulls) the drive cables in a proximal direction to cause the corresponding elongate member to translate and thereby cause the end effector <NUM> to move (articulate) relative to the shaft <NUM>. When both of the jaws <NUM>, <NUM> are designed to move to open and close the end effector <NUM>, one or more first drive cables will be operably coupled to the first jaw <NUM> to move that jaw <NUM> and one or more second drive cables will be operably coupled to the second jaw <NUM> to move that jaw <NUM>. When only one of the jaws <NUM>, <NUM> is configured to move to open and close the end effector <NUM>, one or more drive cables may be operably coupled to the first jaw <NUM> to move the first jaw <NUM> relative to the second jaw <NUM>.

Actuating the drive cables moves the end effector <NUM> between an unarticulated position and an articulated position. The end effector <NUM> is depicted in <FIG> in the unarticulated position where a longitudinal axis A<NUM> of the end effector <NUM> is substantially aligned with the longitudinal axis A<NUM> of the shaft <NUM>, such that the end effector <NUM> is at a substantially zero angle relative to the shaft <NUM>. Due factors such as manufacturing tolerance and precision of measurement devices, the end effector <NUM> may not be at a precise zero angle relative to the shaft <NUM> in the unarticulated position, but nevertheless be considered "substantially aligned" thereto. In the articulated position, the longitudinal axes A<NUM>, A<NUM> would be angularly offset from each other such that the end effector <NUM> is at a non-zero angle relative to the shaft <NUM>.

The drive housing <NUM> (alternately referred to as a "puck") may be releasably latched (attached) to a tool driver of a robotic surgical system in a variety of ways, such as by clamping thereto, clipping thereto, or slidably mating therewith. The actuation devices or mechanisms housed within the drive housing <NUM> may be controlled by the robot based on user inputs received via a computer system incorporated into the robot. Accordingly, the user inputs control movement of the drive cables and consequently movement of the end effector <NUM>.

Example tool drivers to which the drive housing <NUM> may be removably attached are described in previously mentioned <CIT>. Moreover, the drive housing <NUM> illustrated in <FIG> is but one example of a suitable drive housing, and additional embodiments of the drive housing <NUM> are described in previously mentioned <CIT>and <CIT>. Example robotic surgical systems are described in <CIT> entitled "Patient-Side Surgeon Interface for a Teleoperated Surgical Instrument" and previously mentioned <CIT>and <CIT>.

<FIG> is an enlarged isometric view of the distal end of the surgical tool <NUM> of <FIG>. More specifically, <FIG> depicts enlarged views of the end effector <NUM> and the wrist <NUM>, with the end effector <NUM> in the unarticulated position where the jaws <NUM>, <NUM> are closed. The wrist <NUM> operatively couples the end effector <NUM> to the shaft <NUM>. To accomplish this, the wrist <NUM> includes a distal clevis 302a and a proximal clevis 302b. The end effector <NUM> (i.e., the jaws <NUM>, <NUM>) is rotatably mounted to the distal clevis 302a at a first axle 304a, the distal clevis 302a is rotatably mounted to the proximal clevis 302b at a second axle 304b, and the proximal clevis 302b is coupled to a distal end <NUM> of the shaft <NUM>.

The wrist <NUM> provides a first pivot axis P<NUM> that extends through the first axle 304a and a second pivot axis P<NUM> that extends through the second axle 304b. The first pivot axis P<NUM> is substantially perpendicular (orthogonal) to the longitudinal axis A<NUM> of the end effector <NUM>, and the second pivot axis P<NUM> is substantially perpendicular to both the longitudinal axis A<NUM> and the first pivot axis P<NUM>. Movement about the first pivot axis P<NUM> provides "yaw" articulation of the end effector <NUM>, and movement about the second pivot axis P<NUM> provides "pitch" articulation of the end effector <NUM>. The jaws <NUM>, <NUM> are mounted at the first pivot axis P<NUM>, thereby allowing the jaws <NUM>, <NUM> to pivot relative to each other to open and close the end effector <NUM> or alternatively pivot in tandem to articulate the orientation of the end effector <NUM>.

A plurality of drive cables <NUM>, shown as drive cables 308a, 308b, 308c, and 308d, extend longitudinally within a lumen <NUM> of the shaft <NUM> until terminating at the wrist <NUM>. The drive cables 308a-d extend proximally from the end effector <NUM> to the drive housing <NUM> (<FIG>) which, as discussed above, may be configured to facilitate longitudinal movement of the drive cables 308a-d within the lumen <NUM>. The lumen <NUM> can be a single lumen, as illustrated, or can alternatively comprise a plurality of independent lumens that each receive one or more of the drive cables 308a-d.

The wrist <NUM> includes a first plurality of pulleys 312a and a second plurality of pulleys 312b each configured to interact with and redirect the drive cables 308a-d for engagement with the end effector <NUM>. The first plurality of pulleys 312a is mounted to the proximal clevis 302b at the second axle 304b and the second plurality of pulleys 312b is mounted to the proximal clevis 302b at a third axle 304c. The third axle 304c is located proximal to the second axle 304b. The first and second plurality of pulleys 312a,b cooperatively redirect the drive cables 308a-d through an "S" shaped pathway.

In at least one embodiment, one pair of drive cables 308a-d is operatively coupled to each jaw <NUM>, <NUM> and configured to "antagonistically" operate the corresponding jaw <NUM>, <NUM>. For example, the first and second drive cables 308a,b are coupled at a connector <NUM> mounted to the first jaw <NUM>, and the third and fourth drive cables 308c,d are coupled at another connector (hidden in <FIG>) mounted to the second jaw <NUM>. Actuation of the first drive cable 308a acts on the connector <NUM> and thereby pivots the first jaw <NUM> about the first pivot axis P<NUM> toward the open position. In contrast, actuation of the second drive cable 308b acts on the connector <NUM> and thereby pivots the first jaw <NUM> about the first pivot axis P<NUM> in the opposite direction and toward the closed position. Similarly, actuation of the third drive cable 308c acts on the corresponding connector (not shown) and thereby pivots the second jaw <NUM> about the first pivot axis P<NUM> toward the open position, while actuation of the fourth drive cable 308d acts on the corresponding connector to pivot the second jaw <NUM> about the first pivot axis P<NUM> in the opposite direction and toward the closed position.

Accordingly, the drive cables 308a-d may be characterized or otherwise referred to as "antagonistic" cables that cooperatively (antagonistically) operate to cause relative or tandem movement of the first and second jaws <NUM>, <NUM>. When the first drive cable 308a is actuated, the second drive cable 308b naturally follows as coupled to the first drive cable 308a at the connector <NUM>, and vice versa. Similarly, when the third drive cable 308c is actuated, the fourth drive cable 308d naturally follows as coupled to the third drive cable 308c at the other connector (hidden in <FIG>), and vice versa.

According to the present disclosure, the tool <NUM> may further include a power axle cable <NUM>, also extending longitudinally within the lumen <NUM> until terminating at the wrist <NUM> where the distal and proximal clevises 302a,b are coupled. Similar to the drive cables 308a-d, the power axle cable <NUM> extends from the drive housing <NUM> (<FIG>), which houses one or more actuation mechanisms used to selectively actuate the power axle cable <NUM> and thereby facilitate longitudinal movement (translation) of the power axle cable <NUM> within the lumen <NUM>. In some embodiments, the power axle cable <NUM> is a closed loop cable that interfaces with only one actuation mechanism in the drive housing <NUM>. In other embodiments, however, the power axle cable <NUM> may comprise two power axle cables coupled at the distal clevis 302a and each interfacing with an independent mechanism in the drive housing <NUM>, without departing from the scope of the disclosure.

The power axle cable <NUM> is dedicated to transmitting force to the distal clevis 302a, which provides elevated force and load capabilities to the end effector <NUM>. In operation, actuation of the power axle cable <NUM> in a first direction pivots the distal clevis 302a, and therefore the end effector <NUM>, about the second pivot axis P<NUM> in a first "pitch" direction. In contrast, actuation of the power axle cable <NUM> in a second direction opposite the first direction pivots the distal clevis 302a (and the end effector <NUM>) about the second pivot axis P<NUM> in a second "pitch" direction opposite the first pitch direction. As the end effector <NUM> moves in the first and second pitch directions, added force and load is provided to the end effector <NUM>, which enhances its capabilities. This elevated force allows for instruments to be used to retract and grasp large organs or tissues, and to suture and manipulate a needle through thick tissue.

<FIG> is an enlarged cross-sectional side view of the wrist <NUM> and the end effector <NUM> of <FIG>, according to one or more embodiments of the present disclosure. As illustrated and mentioned above, the end effector <NUM> is rotatably mounted to the distal clevis 302a at the first axle 304a, and the distal clevis 302a is rotatably mounted to the proximal clevis 302b at the second axle 304b.

The distal clevis 302a comprises a body <NUM> that provides and otherwise defines a first extension 404a and a second extension 404b laterally offset from the first extension 404a. A cavity <NUM> is defined between the first and second extensions 404a,b and configured to receive a portion of the end effector <NUM>. For example, the cavity <NUM> is sized to receive a proximal portion of each of the first and second jaws <NUM>, <NUM>.

To secure the end effector <NUM> to the distal clevis 302a, the first axle 304a is extendable through first and second holes 408a, 408b defined by the first and second extensions 404a,b, respectively. The first axle 304a is also extendable through corresponding holes <NUM> defined by the end effector <NUM> (i.e., through proximal portions of each jaw <NUM>, <NUM>). Once mounted to the first axle 304a, the end effector <NUM> is capable of rotating about the first pivot axis P<NUM> as acted upon by the corresponding drive cables 308a-d (<FIG>).

As illustrated, a power axle connector <NUM> may be used to mount the power axle cable <NUM> to the distal clevis 302a. The distal clevis 302a may provide an inner pulley <NUM> defining an inner groove <NUM> that concentrically circumscribes the second axle 304b. The power axle cable <NUM> may be received within the inner groove <NUM> and thereby routed concentrically around the second axle 304b, and the power axle connector <NUM> holds the power axle cable <NUM> in place on the distal clevis 302a.

The power axle connector <NUM> may comprise any attachment mechanism capable of mounting the power axle cable <NUM> to the distal clevis 302a such that movement (actuation) of the power axle cable <NUM> on one side of the power axle connector <NUM> correspondingly moves the power axle cable <NUM> on the opposing side of the power axle connector <NUM>. For example, the power axle connector <NUM> may comprise a crimp, such as a ball crimp. Other types of crimps may alternatively be employed including, but not limited to, a barrel crimp, a double barrel crimp, etc. However, the power axle connector <NUM> may alternatively comprise a welded attachment, a brazed attachment, an adhesive bond, a mechanical fastener, and any combination thereof.

The power axle connector <NUM> may be mounted to the distal clevis 302a by being received within a pocket <NUM> defined by the distal clevis 302a. The pocket <NUM> may be sized such that, when the power axle connector <NUM> is received therein, movement of the power axle cable <NUM> causes the power axle connector <NUM> to act on and urge the distal clevis 302a to move about the second pivot axis P<NUM>.

Movement (actuation) of the power axle cable <NUM> in a first direction, for example, will move (rotate) the distal clevis 302a about the second pivot axis P<NUM> in a first or "clockwise" direction. In contrast, movement (actuation) of the power axle cable <NUM> in a second direction opposite the first direction will move (rotate) the distal clevis 302a about the second pivot axis P<NUM> in a second or "counter-clockwise" direction. Moreover, since the end effector <NUM> is coupled to the distal clevis 302a at the first axle 304a, movement of the power axle cable <NUM> will correspondingly pivot the end effector <NUM> about the second pivot axis P<NUM> in the same direction.

The power axle cable <NUM> is dedicated entirely to transmitting force to the distal clevis 302a. Unlike the drive cables 308a,b (<FIG>), which are routed around the first and second pluralities of pulleys 312a,b, the power axle cable <NUM> is routed directly to the distal clevis 302a. Routing the drive cables 308a,b around the first and second pluralities of pulleys 312a,b introduces friction and reduces available load capacity. Since the power axle cable <NUM> is directly routed to the distal clevis 302a, greater force and loading capability for the end effector <NUM> is available.

<FIG> is an isometric side view of the end effector <NUM>, according to one or more embodiments. Again, the illustrated end effector <NUM> includes opposing first and second jaws <NUM>, <NUM> and is movable between open and closed positions as acted upon by the drive cables 308a-d. Moreover, the first and second drive cables 308a,b are coupled at the connector <NUM>, which is mounted to the first jaw <NUM>, and the third and fourth drive cables 308c,d are coupled at another connector (hidden in <FIG>), which is mounted to the second jaw <NUM>.

The connector <NUM> (and the hidden connector) may comprise any attachment mechanism capable of coupling the corresponding drive cables 308a-d such that movement (actuation) of one drive cable correspondingly moves the other associated drive cable, and vice versa. For example, the connector <NUM> (and the hidden connector) may comprise a ball crimp. However, the connector <NUM> (and the hidden connector) may comprise any of the attachment mechanisms mentioned herein with reference to the power axle connector <NUM> of <FIG>.

As illustrated, the connector <NUM> may be received within a pocket <NUM> defined by the first jaw <NUM>. While not visible in <FIG>, the hidden connector mounted to the second jaw <NUM> may likewise be received within a corresponding pocket defined by the second jaw <NUM>. For purposes of the disclosure, only the visible connector <NUM> and pocket <NUM> will be discussed, but it will be appreciated that the discussion may equally apply to the hidden connector and pocket of the second jaw <NUM>, without departing from the scope of the disclosure.

The pocket <NUM> may be sized to receive the connector <NUM> such that movement of the first drive cable 308a correspondingly moves the second drive cable 308b, and vice versa, but also simultaneously urges the connector <NUM> to act on the first jaw <NUM> to move about the first pivot axis P<NUM>. In some embodiments, the end effector <NUM> may further provide a nose <NUM> that helps the first drive cable 308a maintain its position and prevent the first drive cable 308a from "jumping" or slipping out of place while under full yaw articulation. In the illustrated embodiment, the nose <NUM> is an integral extension of the jaw <NUM> and extends therefrom in a direction that essentially traps and stops the connector <NUM> if the connector <NUM> is urged to escape from the pocket <NUM>.

<FIG> is a cross-sectional side view of the distal clevis 302a and the first axle 304a of the wrist <NUM> of <FIG> and <FIG>. In some embodiments, the first hole 408a defined by the first extension 404a may have a first inner diameter 602a and the second hole 408b defined by the second extension 404b may have a second inner diameter 602b greater than the first inner diameter 412a. Moreover, the first axle 304a may be configured and otherwise sized to mate with the first and second holes 408a,b in a press-fit or shrink fit arrangement. Accordingly, the first axle 304a may exhibit a first outer diameter 604a at a first end 606a and a second outer diameter 604b at a second end 606b, where the second outer diameter 604b is less greater the first outer diameter 604a. The first inner diameter 602a may be sized to receive the first outer diameter 604a, and the second inner diameter 602b may be sized to receive the second outer diameter 604b. As will be appreciated, this may prove advantageous in accommodating easy assembly as the first axle 304a will not encounter friction until just prior to both ends 606a,b being press-fit into place into the corresponding holes 408a,b.

<FIG> is a side view of an example embodiment of the end effector <NUM> of <FIG>, according to one or more additional embodiments. The power axle connector <NUM> is seated within the pocket <NUM> defined in the distal clevis 302a and protrudes partially out of the pocket <NUM> and into the cavity <NUM> defined between the first and second extensions 404a,b. The power axle connector <NUM>, however, does not interfere with articulation of the end effector <NUM> due to a recess <NUM> defined on the bottom (proximal portion) of the end effector <NUM>. As illustrated, the recess <NUM> may be sized to accommodate the portion of the power axle connector <NUM> protruding from the pocket <NUM> such that the power axle connector <NUM> does not obstruct movement of the end effector.

<FIG> is an isometric side view of the end effector <NUM> and a portion of the wrist <NUM> of <FIG> and <FIG>, according to one or more additional embodiments. As illustrated, the body <NUM> of the distal clevis 302a may define two hard stops <NUM> (one shown and one hidden) and a plurality of channels <NUM> (two shown and two hidden). Each hard stop <NUM> may comprise a projection defined on the body <NUM> and positioned to limit "yaw" movement of the corresponding jaw <NUM>, <NUM> to a predetermined maximum angle. The hard stop <NUM> is configured to stop yaw articulation of the second jaw <NUM>, while the hidden hard stop on the opposite side of the end effector <NUM> is configured to stop yaw articulation of the first jaw <NUM>. In some embodiments, the predetermined maximum angle may be about <NUM>°, but could alternatively be more or less than <NUM>°, without departing from the scope of the disclosure.

The plurality of channels <NUM> may be configured to receive the drive cables 308a-d extending proximally from the end effector <NUM> on each side thereof. The second and third drive cables 308b,c are shown extending through the two visible channels <NUM>, while the first and fourth drive cables 308a,d extend through two hidden channels on the opposite side of the body <NUM>. The channels <NUM> are sized such that, under normal conditions, the drive cables 308a-d do not engage the channels <NUM> and, therefore, do not introduce friction into the system.

<FIG> is an isometric side view of the end effector <NUM> and a portion of the wrist <NUM> of <FIG> and <FIG>, according to one or more additional embodiments. The proximal clevis 302b is shown in cross-section to expose the first and second pluralities of pulleys 312a,b for discussion. As illustrated, the second axle 304b is larger than the third axle 304c, and the outer diameter of each of the pulleys 312a,b is substantially the same. However, because the second axle 304b is larger than the third axle 304c, an inner diameter 902b of the second plurality of pulleys 312b may be smaller than an inner diameter 902a of the first plurality of pulleys 312a.

As discussed above, the first and second pluralities of pulleys 312a,b cooperatively redirect the drive cables 308a-d (<FIG>) through an "S" shaped pathway extending to and from the end effector <NUM>. The smaller inner diameter 902b of the second plurality of pulleys 312b equates to less bend angle applied to the drive cables 308a-d as they are routed through the "S" shaped pathway. Less bend angle equates to less touching of the drive cables 308a-d against the second plurality of pulleys 312b, which advantageously reduces friction and inefficiencies on the third axle 304c during operation.

<FIG> is an exploded view of the proximal clevis 302b and the distal end <NUM> of the elongate shaft <NUM>, according to one or more embodiments. The proximal clevis 302b may be coupled to the distal end <NUM> of the shaft <NUM> in a variety of ways, without departing from the scope of the disclosure. Example ways that the proximal clevis 302b may be coupled to the distal end <NUM> of the shaft <NUM> include, but are not limited to, a threaded engagement, welding, brazing, an industrial adhesive, one or more mechanical fasteners, an interference fit (e.g., press fit, shrink fit, etc.), or any combination thereof.

In some embodiments, as illustrated, the proximal clevis 302b may be coupled to the distal end <NUM> of the shaft <NUM> by receiving the distal end <NUM> within an interior <NUM> of the proximal clevis 302b. The distal end <NUM> of the shaft <NUM> may define an annular recess <NUM> sized to be received within the interior <NUM> of the proximal clevis 302b. In some embodiments, the annular recess <NUM> may be received within the interior <NUM> via an interference fit (e.g., press fit, shrink fit, etc.). The interference fit coupling may be enhanced through welding, brazing, or an adhesive.

In some embodiments, the distal end <NUM> of the shaft <NUM> may define one or more keyways <NUM> (one shown and one hidden) and one or more corresponding keys <NUM> (one shown and one hidden) may be provided within the interior <NUM> of the proximal clevis 302b. When the distal end <NUM> is received within the interior <NUM>, the keyway(s) <NUM> may be configured to align with and receive the key(s) <NUM>, which prevents rotation of the wrist <NUM> (<FIG>) relative to the shaft <NUM>. Moreover, mating the key(s) <NUM> with the keyway(s) <NUM> may prove advantageous in ensuring that the shaft <NUM> will only couple to the proximal clevis 302b in a predetermined manner angular orientation, which ensures that the wrist <NUM> will be aligned with the shaft <NUM> in a known configuration.

<FIG> is an isometric cross-sectional view of the end effector <NUM> and the wrist <NUM>, according to one or more additional embodiments. More specifically, a view of the interior <NUM> of the proximal clevis 302b is depicted. In some embodiments, the proximal clevis 302b may define a plurality of channels <NUM> configured to receive the drive cables 308a-d (<FIG>) and the power axle cable <NUM>. Accordingly, while only three channels <NUM> are depicted in <FIG>, the number of channels <NUM> will generally be equal to the total number of drive cables 308a-d and the two ends of the power axle cable <NUM>.

In some embodiments, a seal <NUM> may be provided within the interior <NUM> of the proximal clevis 302b. The seal <NUM> may comprise a silicone seal and the drive cables 308a-d (<FIG>) and the power axle cable <NUM> may pass through the seal <NUM> with little or no friction generation. The seal <NUM> may prove advantageous in helping to maintain insufflation during surgical operations, and may also provide a barrier that helps prevent debris, blood, and other matter from getting into the shaft <NUM> (<FIG> and <FIG>) and other parts of a surgical tool.

Embodiments disclosed herein include:
A surgical tool that includes a drive housing, an elongate shaft that extends from the drive housing, a wrist that couples an end effector to the elongate shaft and includes a distal clevis having a first axle that rotatably mounts the end effector to the distal clevis, and a proximal clevis coupled to a distal end of the elongate shaft and having a second axle that rotatably mounts the distal clevis to the proximal clevis, a plurality of drive cables extending between the drive housing and the end effector, wherein movement of one or more of the plurality of drive cables causes the end effector to articulate about a first pivot axis extending through the first axle, and a power axle cable extending from the drive housing and mounted to the distal clevis such that movement of the power axle cable correspondingly pivots the end effector about a second pivot axis extending through the second axle and perpendicular to the first pivot axis.

A method, not claimed, of operating a surgical tool that includes positioning the surgical tool adjacent a patient for operation, the surgical tool including a drive housing, an elongate shaft that extends from the drive housing, a wrist that couples an end effector to the elongate shaft and includes a distal clevis having a first axle that rotatably mounts the end effector to the distal clevis, and a proximal clevis coupled to a distal end of the elongate shaft and having a second axle that rotatably mounts the distal clevis to the proximal clevis, a plurality of drive cables extending between the drive housing and the end effector, and a power axle cable extending from the drive housing and mounted to the distal clevis. The method further including moving one or more of the plurality of drive cables and thereby causing the end effector to articulate about a first pivot axis extending through the first axle, and moving the power axle cable and thereby pivoting the end effector about a second pivot axis extending through the second axle and perpendicular to the first pivot axis.

A power axle wrist for a surgical tool that couples an end effector to an elongate shaft of the surgical tool, the power axle wrist including a distal clevis having a first axle where the end effector is rotatably mounted to the distal clevis, the end effector being articulable about a first pivot axis extending through the first axle, a proximal clevis configured to be coupled to a distal end of the elongate shaft and having a second axle where the distal clevis is rotatably mounted to the proximal clevis, and a power axle cable mounted to the distal clevis such that movement of the power axle cable correspondingly pivots the end effector about a second pivot axis extending through the second axle and perpendicular to the first pivot axis.

Therefore, the disclosed systems are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the invention is defined by the appended claims. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified within the scope of the claims. The systems illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. While compositions and methods are described in terms of "comprising," "containing," or "including" various components or steps, the compositions and methods can also "consist essentially of" or "consist of" the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, "from about a to about b," or, equivalently, "from approximately a to b," or, equivalently, "from approximately a-b") disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles "a" or "an," as used in the claims, are defined herein to mean one or more than one of the elements that it introduces. If there is any conflict in the usages of a word or term in this specification, the definitions that are consistent with this specification should be adopted.

Claim 1:
A power axle wrist (<NUM>) for a surgical tool (<NUM>) that couples an end effector (<NUM>) to an elongate shaft (<NUM>) of the surgical tool, the power axle wrist comprising:
a distal clevis (302a) having a first axle (304a) where the end effector is rotatably mounted to the distal clevis, the end effector being articulable about a first pivot axis (P<NUM>) extending through the first axle;
a proximal clevis (302b) configured to be coupled to a distal end of the elongate shaft and having a second axle (304b) where the distal clevis is rotatably mounted to the proximal clevis;
a power axle cable (<NUM>) mounted to the distal clevis such that movement of the power axle cable correspondingly pivots the end effector about a second pivot axis (P<NUM>) extending through the second axle and perpendicular to the first pivot axis;
a first plurality of pulleys (312a) mounted to the second axle; and
a second plurality of pulleys (312b) mounted to a third axle (304c) coupled to the proximal clevis and located proximal to the second axle; wherein the first and second plurality of pulleys are configured to cooperatively redirect a plurality of drive cables (308a-d) through an S-shaped pathway while the power axle cable is routed directly to the distal clevis;
characterised in that an outer diameter of each pulley of the first and second pluralities of pulleys is the same, but the second axle is larger than the third axle and an inner diameter (902b) of each pulley of the second plurality of pulleys is smaller than an inner diameter (902a) of each pulley of the first plurality of pulleys, and wherein the smaller inner diameter of each second plurality of pulleys equates to less bend angle applied to the drive cables as they are routed through the S-shaped pathway.