Slack cable elimination winch

Abstract

The present invention discloses a surgical tool, which includes: a drive housing; a drive input device and an input shaft, which are rotatably mounted to the drive housing; and a drive assembly, which is mounted to the input shaft and includes an upper capstan that can be rotatably mounted to the input shaft using a first one-way bearing and a lower capstan that can be rotatably mounted to the input shaft using a second one-way bearing. A first drive cable and a second drive cable are connected to the upper capstan and the lower capstan and extend to the end effector of the surgical tool. Rotating the input shaft in a first angular direction causes the lower capstan to be rotationally disengaged from the input shaft and drives the upper capstan in the first angular direction, and rotating the input shaft in a second angular direction causes the upper capstan to be rotationally disengaged from the input shaft and drives the lower capstan in the second angular direction.

Description

Background Art

[0001] Minimally invasive surgical (MIS) instruments are generally preferred over traditional open surgical devices due to reduced postoperative recovery time and minimized scarring. Laparoscopic surgery is a type of MIS surgery in which one or more small incisions are made in the patient's abdomen and a trocar is inserted through the incision to create a path into the abdominal cavity. Through the trocar, a variety of instruments and surgical tools can be introduced into the abdominal cavity. The instruments and tools introduced into the abdominal cavity via the trocar can be used to engage and / or manipulate tissue in a variety of ways to achieve a diagnostic or therapeutic effect.

[0002] Various robotic systems have been developed recently to assist MIS surgery and facilitate more instinctive hand movements by maintaining a natural eye-hand axis. Such robotic systems can also achieve a greater degree of freedom of movement by including an articulated "wrist" joint in the surgical tool that forms a more natural hand-like articulation. In such systems, an end effector positioned at the distal end of the surgical tool can be articulated (moved) using a cable-driven motion system having one or more drive cables (or other elongated members) extending through the wrist joint. A user (e.g., a surgeon) can remotely operate the end effector by grasping and manipulating one or more controllers in space, which are connected to a tool driver connected to the surgical instrument. User input is processed by a computer system incorporated into the robotic surgical system, and the tool driver responds by actuating the cable-driven motion system and thereby actively controlling the tension balance in the drive cable. Moving the drive cable causes the end effector to articulate to a desired angular position and configuration.

[0003] Many mechanical and manufacturing obstacles must be overcome through component design and assembly to achieve consistent and predictable performance of the end effector and its associated cable-driven motion system. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The following drawings are included to illustrate certain aspects of the present disclosure and should not be considered to be exclusive embodiments. The subject matter disclosed herein is capable of numerous modifications, changes, combinations, and equivalents in form and function without departing from the scope of the present disclosure.

[0005] Figure 1 is a block diagram of an exemplary robotic surgical system that may incorporate some or all of the principles of the present disclosure.

[0006] Figure 2 yes Figure 1 An exemplary embodiment of a master console in a master console.

[0007] Figure 3According to one or more embodiments, Figure 1 An example of a robotic manipulator.

[0008] Figure 4 is an isometric view of an exemplary surgical tool that may incorporate some or all of the principles of the present disclosure.

[0009] Figure 5 It shows Figure 4 The wrist may be capable of articulation (pivoting) with potential freedom.

[0010] Figure 6 yes Figure 4 An enlarged isometric view of the distal end of a surgical tool.

[0011] Figure 7 yes Figure 4 Bottom view of the drive housing of a surgical tool.

[0012] Figure 8 yes Figure 6 An isometric exposed view of the interior of a drive housing for a surgical tool.

[0013] Fig.9A and Fig. 9B According to one or more embodiments of the present disclosure Figure 8 Enlarged isometric and exploded views of the drive assembly.

[0014] Fig.10 According to one or more embodiments Figure 8 An exploded isometric view of a portion of the drive assembly. DETAILED DESCRIPTION

[0015] The present disclosure relates to robotic surgical systems and, more particularly, to a capstan drive assembly designed to remove slack in a drive cable by ensuring that minimum cable tension is maintained.

[0016] The embodiments discussed herein describe a surgical tool that includes a drive housing having an elongated shaft extending therefrom and an end effector operatively coupled to the distal end of the elongated shaft. A drive input device and an input shaft are rotatably mounted to the drive housing, and a drive assembly is mounted to the input shaft and includes an upper capstan that is rotatably mounted to the input shaft using a first one-way bearing and a lower capstan that is rotatably mounted to the input shaft using a second one-way bearing. A first drive cable is coupled to the upper capstan and extends to the end effector, and a second drive cable is coupled to the lower capstan and extends to the end effector. Rotating the input shaft in a first angular direction causes the lower capstan to rotationally disengage from the input shaft, and drives the upper capstan in the first angular direction to pull the first drive cable in a first linear direction. Rotating the input shaft in a second angular direction opposite to the first angular direction causes the upper capstan to rotationally disengage from the input shaft, and drives the lower capstan in the second angular direction to pull the second drive cable in a second linear direction opposite to the first linear direction.

[0017] Figures 1 to 3 The structure and operation of an exemplary robotic surgical system and its associated components are shown. Although applicable to robotic surgical systems, it should be noted that the principles of the present disclosure may be equally or alternatively applicable to non-robotic surgical systems without departing from the scope of the present disclosure.

[0018] Figure 1 1 is a block diagram of an exemplary robotic surgical system 100 that may incorporate some or all of the principles of the present disclosure. As shown, the system 100 may include at least one master console 102a and at least one robotic manipulator 104. The robotic manipulator 104 may be mechanically and / or electrically coupled to or otherwise include one or more robotic arms 106. In some embodiments, the robotic manipulator 104 may be mounted to a transport cart (alternatively referred to as an "arm cart") that enables mobility of the robotic manipulator 104 and associated robotic arms 106. Each robotic arm 106 may include and otherwise provide a tool driver, wherein one or more surgical instruments or tools 108 may be mounted for performing various surgical tasks on a patient 110. The operation of the robotic arms 106, corresponding tool drivers, and associated tools 108 may be directed by a clinician 112a (e.g., a surgeon) from the master console 102a.

[0019] In some embodiments, a second master console 102b (shown in phantom) operated by a second clinician 112b may also help direct the operation of the robotic arms 106 and tools 108 with the first clinician 112a. In such embodiments, for example, each clinician 112a, 112b may control a different robotic arm 106, or in some cases, full control of the robotic arm 106 may be passed between the clinicians 112a, 112b. In some embodiments, additional robotic manipulators with additional robotic arms may be used on the patient 110 during the surgical procedure, and these additional robotic arms may be controlled by one or more of the master consoles 102a, 102b.

[0020] The robot manipulator 104 and the main console 102a, 102b can communicate with each other via a communication link 114, which can be any type of wired or wireless communication link configured to carry a signal of a suitable type (e.g., an electrical signal, an optical signal, an infrared signal, etc.) according to any communication protocol. The communication link 114 can be an actual physical link, or it can be a logical link using one or more actual physical links. When the link is a logical link, the type of the physical link can be a data link, an uplink, a downlink, an optical fiber link, a point-to-point link, for example, those used to refer to communication facilities connecting network nodes as known in the field of computer networks. Therefore, the clinician 112a, 112b can remotely control the robot arm 106 via the communication link 114, so that the clinician 112a, 112b can remotely operate the patient 110.

[0021] Figure 2 Can be used to control Figure 1 104. As shown in the figure, the main console 102a may include a support member 202, a clinician 112a, 112b ( Figure 1 ) may rest his / her forearm on the support while grasping one or more user input devices (not shown). The user input devices may include, for example, physical controllers such as, but not limited to, joysticks, exoskeleton gloves, master manipulators, etc., and may be capable of moving in multiple degrees of freedom to control the surgical tool 108 ( Figure 1 In some embodiments, the main console 102a may also include one or more foot switches 204 that may be engaged by the clinicians 112a, 112b to change the configuration of the surgical system and / or generate additional control signals to control the operation of the surgical tool 108.

[0022] When clinicians 112a, 112b ( Figure 1) can manipulate the user input device and / or foot switch 204 while viewing the procedure via the visual display 206. The image displayed on the visual display 206 can be obtained from an endoscopic camera or "endoscope". In some embodiments, the visual display 206 may include or otherwise incorporate a force feedback meter or "force indicator" that provides the clinician 112a, 112b with a visual indication of the magnitude of the force being applied by the surgical tool (i.e., a cutting instrument or a dynamic clamping member) and the direction in which the force is being applied. As will be appreciated, other sensor arrangements may be used to provide the main console 102a with indications of other surgical tool metrics, such as, for example, whether a staple cartridge has been loaded into the end effector or whether the anvil has been moved to a closed position prior to firing.

[0023] Figure 3 An example of a robotic manipulator 104 that can be used to operate a plurality of surgical tools 108 according to one or more embodiments is shown. As shown, the robotic manipulator 104 can include a base 302 supporting a vertically extending column 304. A plurality of robotic arms 106 (three are shown) can be operatively coupled to the column 304 at a carriage 306 that can be selectively adjusted to change the height of the robotic arms 106 relative to the base 302, as indicated by arrow A.

[0024] The robotic arms 106 may include links (alternatively referred to as "device joints") that are capable of manual articulation. In the illustrated embodiment, the surgical tools 108 are mounted to corresponding tool drivers 308 disposed on each robotic arm 106. Each tool driver 308 may include one or more drivers or motors for interacting with one or more corresponding drive input devices of the surgical tool 108, and actuation of the drive input devices causes the associated surgical tool 108 to operate.

[0025] One of the surgical tools 108 may include an image capture device 310, such as an endoscope, which may include, for example, a laparoscope, an arthroscope, a hysteroscope, or may alternatively include some other imaging modality, such as ultrasound, infrared, fluoroscopy, magnetic resonance imaging, etc. The image capture device 310 has a viewing end located at the distal end of the elongated shaft, which allows the viewing end to be inserted through a portal into an internal surgical site of a patient's body. The image capture device 310 may be communicatively coupled to the visual display 206 ( Figure 2 ) and is capable of transmitting images in real time for display on a visual display 206.

[0026] The remaining surgical tools may be communicatively coupled to the surgical tools provided by the clinicians 112a, 112b ( Figure 1 ) at the main console 102a ( Figure 2) is a user input device held at a position 112 of the robot arm 106. The movement of the robotic arm 106 and the associated surgical tool 108 can be controlled by the clinician 112a, 112b manipulating the user input device. As described in more detail below, the surgical tool 108 may include or otherwise incorporate an end effector mounted on a corresponding articulated wrist that is pivotally mounted on the distal end of an associated elongated shaft. The elongated shaft allows the end effector to be inserted through a portal into an internal surgical site of the patient's body, and the user input device also controls the movement (actuation) of the end effector.

[0027] In use, the robotic manipulator 104 is positioned near a patient requiring surgery and then typically caused to remain stationary until the surgery to be performed has been completed. The robotic manipulator 104 typically has wheels or casters to enable its movement. The lateral and vertical positioning of the robotic arm 106 can be controlled by the clinicians 112a, 112b ( Figure 1 ) is set to facilitate the delivery of the elongated shaft of the surgical tool 108 and the image capture device 310 through the portal to a desired position relative to the surgical site. When the surgical tool 108 and the image capture device 310 are so positioned, the robotic arm 106 and the carriage 306 can be locked in place.

[0028] Figure 4 is an isometric view of an exemplary surgical tool 400 that may incorporate some or all of the principles of the present disclosure. The surgical tool 400 may be used with Figure 1 and Figure 3 The surgical tool 108 is the same as or similar to the surgical tool 108 of the present invention and can therefore be used with a robotic surgical system such as Figure 1 Thus, the surgical tool 400 may be designed to be releasably coupled to a tool driver included in the robotic surgical system 100. However, in other embodiments, aspects of the surgical tool 400 may be adapted for use in a manual or hand-operated manner without departing from the scope of the present disclosure.

[0029] As shown, surgical tool 400 includes an elongated shaft 402, an end effector 404, a wrist 406 (alternatively referred to as a "wrist joint" or "articulating wrist joint") coupling the end effector 404 to the distal end of the shaft 402, and a drive housing 408 coupled to the proximal end of the shaft 402. In the context of surgical tools and robotic surgical systems (e.g., Figure 1 In applications where the surgical tool 400 is used in conjunction with a robotic surgical system 100 , the drive housing 408 may include a coupling feature structure for releasably coupling the surgical tool 400 to the robotic surgical system.

[0030] The terms "proximal" and "distal" are defined herein with respect to a robotic surgical system having an interface configured to mechanically and electrically couple a surgical tool 400 (e.g., housing 408) to a robotic manipulator. The term "proximal" refers to a location of an element closer to the robotic manipulator, and the term "distal" refers to a location of an element closer to the end effector 404 and thus further away from the robotic manipulator. Alternatively, in manual or hand-operated applications, the terms "proximal" and "distal" are defined herein with respect to a user such as a surgeon or clinician. The term "proximal" refers to a location of an element closer to the user, and the term "distal" refers to a location of an element closer to the end effector 404 and thus further away from the user. In addition, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used with respect to exemplary embodiments as they are shown in the figures, with the upward or upper direction toward the top of the corresponding figure and the downward or lower direction toward the bottom of the corresponding figure.

[0031] During use of the surgical tool 400, the end effector 404 is configured to be able to move (pivot) relative to the shaft 402 at the wrist 406 to position the end effector 404 at a desired orientation and position relative to the surgical site. To achieve this, the housing 408 includes (contains) various drive input devices and mechanisms (e.g., gears, actuators, etc.) that are designed to control the operation of various feature structures associated with the end effector 404 (e.g., clamping, firing, rotation, joint movement, cutting, etc.). In at least some embodiments, the shaft 402 and therefore the end effector 404 coupled thereto are configured to be able to rotate around the longitudinal axis A1 of the shaft 402. In such embodiments, at least one of the drive input devices included in the housing 408 is configured to be able to control the rotational movement of the shaft 402 around the longitudinal axis A1.

[0032] The surgical tool 400 may have any of a variety of configurations capable of performing at least one surgical function. For example, the surgical tool 400 may include, but is not limited to, clamps, graspers, needle drivers, scissors, electrocautery tools, staplers, clip appliers, hooks, scrapers, suction tools, irrigation tools, imaging devices (e.g., endoscopes or ultrasound probes), or any combination thereof. In some embodiments, the surgical tool 400 may be configured to apply energy, such as radio frequency (RF) energy, to the tissue. In the illustrated embodiment, the end effector 404 includes a tissue grasper and a vessel sealer, which includes opposing jaws 410, 412 that are configured to be able to move (articulate) between an open position and a closed position. However, as will be appreciated, the opposing jaws 410, 412 may alternatively form part of other types of end effectors, such as, but not limited to, surgical scissors, clip appliers, needle drivers, babcock forceps including a pair of opposing grasping jaws, bipolar jaws (e.g., bipolar Maryland graspers, clamps, fenestrated graspers, etc.), etc. One or both of the jaws 410, 412 may be configured to be pivotable to allow articulation of the end effector 404 between an open position and a closed position.

[0033] The shaft 402 is an elongated member extending distally from the housing 408 and having at least one lumen extending therethrough along its axial length. In some embodiments, the shaft 402 may be fixed to the housing 408, but may alternatively be rotatably mounted to the housing 408 to allow the shaft 402 to rotate about the longitudinal axis A1. In other embodiments, the shaft 402 may be releasably coupled to the housing 408, which may allow a single housing 408 to be adapted for various shafts having different end effectors.

[0034] Figure 5 404. The potential degrees of freedom in which the wrist 406 may be able to articulate (pivot) are shown. The wrist 406 may have any of a variety of configurations. Typically, the wrist 406 includes a joint that is configured to allow pivotal movement of the end effector 404 relative to the axis 402. The degrees of freedom of the wrist 406 are represented by three translational variables (i.e., pitch, heave, and yaw) and 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 the surgical system (e.g., the end effector 404) relative to a given reference Cartesian coordinate system. As shown in FIG. Figure 5 As shown, "pitch" refers to forward and backward translational motion, "heave" refers to up and down translational motion, and "yaw" refers to left and right translational motion. Regarding rotational terms, "roll" refers to left and right tilt, "pitch" refers to forward and backward tilt, and "yaw" refers to left and right rotation.

[0035] The pivoting motion may include pitch motion around a first axis (e.g., X-axis) of the wrist 406, yaw motion around a second axis (e.g., Y-axis) of the wrist 406, and combinations thereof to allow 360° rotational motion of the end effector 404 around the wrist 406. In other applications, the pivoting motion may be limited to motion in a single plane, such as only pitch motion around a first axis of the wrist 406 or only yaw motion around a second axis of the wrist 406, such that the end effector 404 moves only in a single plane.

[0036] See again Figure 4 The surgical tool 400 may also include a plurality of drive cables (in Figure 4 404 is configured to facilitate movement and articulation of the end effector 404 relative to the shaft 402. Moving (actuating) at least some of the drive cables causes the end effector 404 to move between the non-articulated position and the articulated position. Figure 4 404 is shown in a non-articulated position in which the longitudinal axis A2 of the end effector 404 is substantially aligned with the longitudinal axis A1 of the shaft 402 such that the end effector 404 is at a substantially zero angle relative to the shaft 402. In the articulated position, the longitudinal axes A1, A2 will be angularly offset from each other such that the end effector 404 is at a non-zero angle relative to the shaft 402.

[0037] In some embodiments, the surgical tool 400 can be supplied with power (electrical current) via a power cable 414 coupled to the housing 408. In other embodiments, the power cable 414 can be omitted, and power can be supplied to the surgical tool 400 via an internal power source, such as one or more batteries or fuel cells. In such embodiments, the surgical tool 400 can alternatively be characterized and otherwise referred to herein as an "electrosurgical instrument" capable of providing electrical energy to the end effector 404.

[0038] The power cable 414 can place the surgical tool 400 in communication with a generator 416 that supplies energy (such as electrical energy (e.g., radio frequency energy), ultrasonic energy, microwave energy, thermal energy, or any combination thereof) to the surgical tool 400 and, more specifically, the end effector 404 to cauterize and / or coagulate tissue. Thus, the generator 416 can include a radio frequency (RF) source, an ultrasonic source, a direct current power source, and / or any other suitable type of electrical energy source that can be activated independently or simultaneously.

[0039] Figure 6 yes Figure 4 An enlarged isometric view of the distal end of the surgical tool 400. More specifically, Figure 6An enlarged view of the end effector 404 and wrist 406 is shown with the jaws 410, 412 of the end effector 404 in an open position. The wrist 406 operatively couples the end effector 404 to the shaft 402. However, in some embodiments, a shaft adapter may be directly coupled to the wrist 406 and otherwise interposed between the shaft 402 and the wrist 406. Thus, the wrist 406 may be operatively coupled to the shaft 402 via a direct coupling engagement, in which the wrist 406 is directly coupled to the distal end of the shaft 402, or an indirect coupling engagement, in which the shaft adapter is interposed between the wrist 406 and the distal end of the shaft 402. As used herein, the term "operatively coupled" refers to either a direct or indirect coupling engagement.

[0040] To operatively couple the end effector 404 to the shaft 402, the wrist 406 includes a first link or "distal" link 602a, a second link or "intermediate" link 602b, and a third link or "proximal" link 602c. The links 602a-602c are configured to facilitate articulation of the end effector 404 relative to the shaft 402, for example, to allow the end effector 404 to move relative to the longitudinal axis A1 ( Figure 4 ) is angled. In the illustrated embodiment, the articulation via the links 602a to 602c may be limited to pitch only, yaw only, or a combination thereof. As shown, the distal link 602a may be coupled to the end effector 404, and more specifically to the lower jaw 412 (or an extension of the lower jaw 412). The distal link 602a may also be rotatably coupled to the intermediate link 602b at the first shaft 604a, and the intermediate link 602b may be rotatably coupled to the proximal link 602c at the second shaft 604b. The proximal link 602c may then be coupled to the distal end 606 of the shaft 402 (or alternatively to a shaft adapter).

[0041] The wrist 406 provides a first pivot axis P1 extending through the first shaft 604a and a second pivot axis P2 extending through the second shaft 604b. The first pivot axis P1 is substantially perpendicular (orthogonal) to the longitudinal axis A2 ( Figure 4 ), and the second pivot axis P2 is substantially perpendicular (orthogonal) to both the longitudinal axis A2 and the first pivot axis P1. Movement about the first pivot axis P1 provides a "yaw" joint movement of the end effector 404, and movement about the second pivot axis P2 provides a "pitch" joint movement of the end effector 404. Alternatively, the first pivot axis P1 can be configured to provide a "pitch" joint movement, and the second pivot axis P2 can be configured to provide a "yaw" joint movement.

[0042] A plurality of drive cables, shown as drive cables 608a, 608b, 608c, and 608d, extend longitudinally within a lumen 610 defined by the shaft 402 (and / or a shaft adapter) and through the wrist 406 to be operatively coupled to the end effector 404. As shown, the lumen 610 may be a single lumen, or may alternatively include a plurality of separate lumens that each receive one or more of the drive cables 608a-608d.

[0043] The drive cables 608a-608d form part of the cable driven motion system briefly described above, and may be referred to and otherwise characterized as cables, ribbons, wires, cords, wires, ropes, wires, twisted wires, elongated members, etc. The drive cables 608a-608d may be made of a variety of materials, including but not limited to metals (e.g., tungsten, stainless steel, etc.), polymers (e.g., ultra high molecular weight polyethylene), synthetic fibers (e.g., etc.) or any combination thereof. Figure 6 Four drive cables 608a-608d are shown in FIG. 6 , but more or less than four drive cables 608a-608d may be included without departing from the scope of the present disclosure.

[0044] Drive cables 608a-608d extend proximally from the end effector 404 to the drive housing 408 ( Figure 4 ), where they are operatively coupled to respective actuation mechanisms (e.g., capstans) or devices housed therein to facilitate longitudinal movement (translation) of the drive cables 608a-608d within the lumen 610. Selective actuation of all or a portion of the drive cables 608a-608d causes the end effector 404 to articulate (pivot) relative to the shaft 402. More specifically, selective actuation causes the corresponding drive cables 608a-608d to translate longitudinally within the lumen 610 and thereby cause pivotal movement of the end effector 404 at the wrist 406. Moving the drive cables 608a-608d can be accomplished in a variety of ways, such as by triggering a trigger operatively coupled to the drive housing 408 ( Figure 4 ) or an associated actuator or mechanism (e.g., a capstan) contained within the drive housing. Moving a given drive cable 608a-608d constitutes applying tension (i.e., pulling force) to the given drive cable 608a-608d in a proximal direction, which causes the given drive cable 608a-608d to translate and thereby cause the end effector 404 to move (articulate) relative to the shaft 402. As will be appreciated, applying tension to and moving one drive cable 608a-608d may result in the drive cable 608a-608d slacking angularly (or diagonally) relative to the moving drive cable 608a-608d. Embodiments of the present disclosure may be configured to reduce this incidence.

[0045] The drive cables 608a-608d each extend longitudinally through the first, second, and third links 602a-602c and terminate at the first link 602a, thereby operatively coupling each drive cable 608a-608d to the end effector 404, and more specifically to the lower jaw 412. In some embodiments, as shown, the distal end of each drive cable 608a-608d may include a ball crimp 612 (only one is shown). In other embodiments, the distal end of each drive cable 608a-608d may include a weld, an adhesive attachment, a press fit, or any combination of the foregoing.

[0046] In some embodiments, the electrical conductor 614 can supply electrical energy to the end effector 404, and more specifically to the electrode 616 included in the end effector 404. The electrical conductor 614 extends longitudinally within the lumen 610, passes through the wrist 406, and terminates at the electrode 616. The end effector 404 can be configured for monopolar or bipolar operation. In the illustrated embodiment, the electrode 616 is mounted to the lower jaw 412 or otherwise forms a part of the lower jaw. However, in other embodiments, the electrode 616 can form a part of the upper jaw 410, or can alternatively be connected to both jaws 410, 412 or form a part of both jaws. In some embodiments, the electrical conductor 614 and the power cable 414 ( Figure 4 ) may include the same structure. However, in other embodiments, the electrical conductor 614 may be electrically coupled to the power cable 414. In other embodiments, the electrical conductor 614 may extend to the drive housing 408 where it is electrically coupled to an internal power source, such as a battery or fuel cell.

[0047] In the illustrated embodiment, the end effector 404 includes a vessel sealer that includes a knife or "cutting element" 618 (mostly occluded) that is configured to be able to advance and retract within a groove or slot 620 longitudinally defined in one or both of the upper jaw 410 and the lower jaw 412. In an exemplary operation, the jaws 410, 412 can be actuated to close and grasp onto tissue, after which the cutting element 618 can be advanced distally along the slot 620 to cut the grasped tissue. Alternatively, the cutting element 618 can be deployed after applying electrical energy to transect the coagulated tissue.

[0048] The jaws 410, 412 can be moved between a closed position and an open position by pivoting the upper jaw 410 relative to the lower jaw 412. In the illustrated embodiment, the upper jaw 410 can be rotatably coupled (mounted) to the lower jaw 412 at a jaw shaft 622. The third pivot axis P3 extends through the jaw shaft 622 and is generally perpendicular (orthogonal) to the first pivot axis P1 and parallel to the second pivot axis P2. A center pulley 624 (partially visible) can be mounted to the jaw shaft 622 and receives a jaw cable 626 that can be actuated to selectively open and close the jaws 410, 412.

[0049] Similar to the drive cables 608a-608d, the jaw cable 626 extends longitudinally within the lumen 610 and through the wrist 406. In addition, the jaw cable 626 can form part of the cable-driven motion system described herein and, thus, can extend proximally from the end effector 404 to the drive housing 408 ( Figure 4 ). In some embodiments, the jaw cable 626 includes two wires or cords connected at or near the center pulley 624 and extending proximally to the drive housing 408. However, in other embodiments, the jaw cable 626 may include a single wire or cord that encircles the center pulley 624, and the opposing first and second ends 628a, 628b of the jaw cable 626 extend proximally to the drive housing 408.

[0050] Figure 7 408 according to one or more embodiments. As shown, the drive housing 408 may include a tool mounting interface 702 for operatively coupling the drive housing 408 to a robotic manipulator (e.g., Figure 3 and Figure 5 The tool mounting interface 702 may releasably couple the drive housing 408 to the tool driver in various ways, such as by clamping thereto, clipping thereto, or slidably engaging therewith. The tool mounting interface 702 may include an array of electrical connection pins that may be coupled to electrical connectors on a mounting surface of the tool driver. Thus, the tool mounting interface 702 may mechanically, magnetically, and / or electrically couple the drive housing 408 to the tool driver.

[0051] As shown, the interface 702 includes and supports a plurality of input devices, such as drive input devices 704a, 704b, 704c, 704d, 704e and 704f. Each drive input device 704a to 704f may include a rotatable disk, which is configured to be able to align and connect with the corresponding actuator of a given tool driver. Each drive input device 704a to 704f may provide or define one or more surface feature structures 706, which are configured to be able to align and cooperate with the corresponding feature structures provided on a given actuator. The surface feature structure 706 may include, for example, various protrusions and / or recesses that are conducive to mating engagement. Each drive input device in the drive input device 704a to 704f may be actuated based on a user input transmitted to the tool driver coupled to the interface 702, and the user input may be received via a computer system incorporated into the robotic surgical system.

[0052] In some embodiments, actuation of the first drive input device 704a can be configured to control the rotation of the shaft 402 about its longitudinal axis A1. The shaft 402 can rotate clockwise or counterclockwise depending on the rotation direction of the first drive input device 704a. In some embodiments, actuation of the second drive input device 704b can be configured to advance or retract the cutting element 618 ( Figure 6 In some embodiments, actuation of the third drive input device 704c and the fourth drive input device 704d can be configured to open and close the jaws 410, 412 ( Figure 4 and Figure 6 ). More specifically, the jaw cable 626 ( Figure 6 ) of the first end 628a and the second end 628b ( Figure 6 ) can extend to and be operably connected to corresponding drive input devices in the third drive input device 704c and the fourth drive input device 704d, so that coordinated actuation of the third drive input device 704c and the fourth drive input device 704d causes the jaw cable 626 to open / close the jaws 410, 412.

[0053] In some embodiments, actuation of the fifth drive input 704e and the sixth drive input 704f can be configured to axially translate the drive cables 608a-608d ( Figure 6 ), and thereby the end effector 404 ( Figure 4 and Figure 6) to perform joint movement. More specifically, two drive cables 608a-608d are operably coupled to each drive input device 704e, 704f, such that actuation of the fifth drive input device 704e causes two drive cables 608a-608d to translate axially, and actuation of the sixth drive input device 704f causes the other two drive cables 608a-608d to translate axially. In one embodiment, for example, the second drive cable 608b and the third drive cable 608c may be driven by actuation of the fifth drive input device 704e, and the first drive cable 608a and the fourth drive cable 608d may be driven by actuation of the sixth drive input device 704e.

[0054] Figure 8 408 is an isometric exposed view of the interior of the drive housing 408 according to one or more embodiments. Several components that would otherwise be included within the drive housing 408 are not shown. Figure 8 , in order to facilitate discussion of the components shown. More specifically, Figure 8 The sixth drive input device 704f ( Figure 7 ) and a plurality of holes 802 are defined in the drive housing 408, wherein additional drive components (not shown) would otherwise be mounted to the drive housing 408 and associated with the first to fifth drive input devices 704a to 704e, respectively.

[0055] The drive assembly 800 may include or otherwise be mounted to an input shaft 804. The input shaft 804 is operatively coupled to the sixth drive input device 704f ( Figure 7 ) or otherwise extends from the sixth drive input device, so that actuation of the sixth drive input device 704f correspondingly rotates the input shaft 804.

[0056] The drive assembly 800 may also include a first or "upper" winch assembly 806a and a second or "lower" winch assembly 806b, and each winch assembly 806a, 806b may be rotatably mounted to the input shaft 804. The upper winch assembly 806a includes a first or "upper" winch 808a, and the lower winch assembly 806b includes a second or "lower" winch 808b. Each winch in the winches 808a, 808b may have a drive cable coupled thereto (i.e., wound around it) and extending therefrom. In the illustrated embodiment, the first drive cable 608a (shown as a dotted line) is coupled to the upper winch 808a, and the fourth drive cable 608d (shown as a dotted line) is coupled to the lower winch 808a. Each drive cable 608a, 608d extends from the corresponding winch 808a, 808b and extends out of the drive housing 408. As will be appreciated, the first drive cable 608a and the fourth drive cable 608d may alternatively be coupled to the opposing winches 808a, 808b without departing from the scope of the present disclosure. Figure 6 Any combination of two of the drive cables 608a-608d may be coupled to the capstans 808a, 808b.

[0057] The upper capstan 808a is operably coupled to the input shaft 804 such that rotating the input shaft 804 in a first angular direction 810a (e.g., clockwise) correspondingly drives the upper capstan 808a in the first angular direction 810a, which causes the first drive cable 608a to be pulled in a first linear direction 812a (e.g., proximally) and correspondingly winds around the upper capstan 808a. Additionally, rotating the input shaft 804 in the first angular direction 810a will rotationally disengage the lower capstan 808b from the input shaft 804 and allow the input shaft 804 to rotate relative to the lower capstan 808b. Thus, when the input shaft 804 is rotated in the first angular direction 810a, the fourth drive cable 608d may be allowed to move in a second linear direction 812b (e.g., distally) opposite to the first linear direction 812a, if desired, and may otherwise be unwound from the lower capstan 808b to help maintain a sufficient tensile load. In at least one embodiment, the length (linear distance) of the first drive cable 608a wound onto the upper capstan 808a when the input shaft 804 rotates in the first angular direction 810a can be substantially the same as the length (linear distance) of the fourth drive cable 608d unwound from the lower capstan 808b.

[0058] Conversely, the lower capstan 808b is operably coupled to the input shaft 804 such that rotating the input shaft 804 in a second angular direction 810b (e.g., counterclockwise) opposite to the first angular direction 810a correspondingly drives the lower capstan 808b in the second angular direction 810a, which causes the fourth drive cable 608d to be pulled in a second linear direction 812b and correspondingly wind around the lower capstan 808b. Additionally, rotating the input shaft 804 in the second angular direction 810b will rotationally disengage the upper capstan 808a from the input shaft 804, thereby allowing the input shaft 804 to rotate relative to the upper capstan 808a. Thus, when the input shaft 804 rotates in the second angular direction 810b, the first drive cable 608a may be allowed to move in the second linear direction 812b, if desired, and may otherwise be unwound from the upper capstan 808a to help maintain a sufficient tensile load. In at least one embodiment, the length (linear distance) of the fourth drive cable 608b wound onto the lower capstan 808b when the input shaft 804 rotates in the second angular direction 810b can be substantially the same as the length (linear distance) of the first drive cable 608a unwound from the upper capstan 808a.

[0059] Fig.9A and Fig. 9B 800 according to one or more embodiments of the present disclosure. As shown, the input shaft 804 includes a generally elongated body having a first end or upper end 902a and a second end or lower end 902b opposite the upper end 902a. The sixth drive input device 704f is operably connected to the lower end 902b. In some embodiments, for example, the sixth drive input device 704f can be mechanically fastened to the lower end 902b, such as using screws. Alternatively, the input shaft 804 can form an integral extension of the sixth drive input device 704f. The drive assembly 800 may also include a flange bushing 904a that is configured to help rotatably mount the sixth drive input device 704f to the drive housing 408 ( Figure 4 , Figure 7 and Figure 8 ). However, the flange bushing 904a may be optional.

[0060] In the illustrated embodiment, the upper capstan assembly 806a may include an upper capstan 808a, an adapter or housing 906, and a first one-way bearing 908a (in Fig. 9B As shown, the upper capstan 808a includes a first spiral groove 910a that extends around at least a portion of the outer circumference of the upper capstan 808a. The first spiral groove 910a can be configured to receive a drive cable, such as the first drive cable 608a ( Figure 6 and Figure 8The end of the first drive cable 608a may be fixedly attached to the upper capstan 808a, and when the upper capstan 808a rotates, the first drive cable 608a may be released (ie, unwound) or pulled in according to the direction of rotation.

[0061] The upper capstan 808a may be configured to mate with the adapter 906. In some embodiments, such as in Fig. 9B As best seen in FIG. 1 , the upper capstan 808a may provide or otherwise define a first mating structure 912a, and the adapter 906 may provide or otherwise define a second mating structure 912b (in FIG. 10 ) that may mate with the first mating structure 912a. Fig. 9B 906). When the first mating structure 912a and the second mating structure 912b are properly matched, the upper capstan 808a and the adapter 906 will rotate as a single integral body. The first mating structure 912a and the second mating structure 912b may include any mating engagement that can be matched to fix the upper capstan 808a to the adapter 906 rotationally, and vice versa. In the illustrated embodiment, the first mating structure 912a and the second mating structure 912b are mating castellations or castellations (interlocking) feature structures defined on each component. However, in other embodiments, the first mating structure 912a and the second mating structure 912b may alternatively include a dovetail joint, a tongue-and-groove joint, a pin or clamp engaged with a mating hole, a spline joint, an interference or shrink fit joint, welding, adhesive bonding, or any combination thereof.

[0062] In at least one embodiment, the upper capstan assembly 806a may also include a flange bushing 904b that may help the upper capstan 808a mate with the adapter 906. However, in other embodiments, the flange bushing 904b may be omitted without departing from the scope of the present disclosure. The flange bushing 904b serves as a flange plane bearing to reduce the upper capstan 808a and the drive housing 408 ( Figure 4 ) to support the friction between the frame structure (not shown) of the upper capstan 808a.

[0063] The adapter 906 may define a cavity 914 that is sized to receive a first one-way bearing 908a. The first one-way bearing 908a may include any type of bearing that allows rotation in one angular direction but prevents rotation in the opposite direction. The first one-way bearing 908a may include, for example, a one-way clutch bearing, a wedge-type bearing, an anti-reverse bearing, or any combination thereof. In at least one embodiment, the first one-way bearing 908a may include a ratchet mechanism that allows rotation in a first direction but prohibits rotation in a second direction. The first one-way bearing 908a may be fixed in the cavity 914 via a variety of attachment means, including but not limited to interference fit, mechanical attachment, welding, adhesive, or any combination thereof. When the upper capstan assembly 806a is assembled on the input shaft 704, the inner radial surface 916 of the first one-way bearing 908a may be positioned to engage the outer radial surface of the input shaft 704 at or near the upper end 902a.

[0064] Thus, in at least one embodiment, the upper capstan 808a may be rotatably mounted to the input shaft 804 via the adapter 906 and the first one-way bearing 908a. However, in other embodiments, the adapter 906 may be omitted from the upper capstan assembly 806a. In such embodiments, the first one-way bearing 908a may alternatively be fixed to the upper capstan 808a.

[0065] In some embodiments, the first one-way bearing 908a may not be able to rotate in the first angular direction 810a, but may be allowed to rotate in the second angular direction 810b. Therefore, when the input shaft 804 rotates in the first angular direction 810a, the first one-way bearing 908a may be constrained against the input shaft 804 and transfer torque from the input shaft 804 to the upper capstan 808a, thereby driving the upper capstan 808a in the first angular direction 810a. As described above, rotating the upper capstan 808a in the first angular direction 810a may cause the first drive cable 608a ( Figure 6 and Figure 8 However, when the input shaft 804 is rotated in the second angular direction 810b, the first one-way bearing 908a can allow the upper capstan 808a to be rotationally disengaged from the input shaft 804 and thereby allow free movement of the input shaft 804 to rotate relative to the upper capstan 808a.

[0066] The lower capstan assembly 806b may include a lower capstan 808b and a second one-way bearing 908b (in Fig. 9B As shown, the lower capstan 808b includes a second spiral groove 910b that extends around at least a portion of the outer circumference of the lower capstan 808b. The second spiral groove 910b can be configured to receive a drive cable, such as the fourth drive cable 608d ( Figure 6 and Figure 8The end of the fourth drive cable 608d may be fixedly attached to the lower winch 808b, and when the lower winch 808b rotates, the fourth drive cable 608d may be released (ie, unwound) or pulled in according to the direction of rotation.

[0067] The second one-way bearing 908b is operably coupled to the lower capstan 808b. In one embodiment, for example, the second one-way bearing 908b can be received within a cavity (not shown) defined by the lower capstan 808b and can be secured within the cavity via an interference fit, mechanical attachment, welding, adhesive, or any combination thereof. When the lower capstan assembly 806b is assembled on the input shaft 704, the inner radial surface 918 of the second one-way bearing 908b can be positioned to engage the outer radial surface of the input shaft 704 at or near the upper end 902a.

[0068] Similar to the first one-way bearing 908a, the second one-way bearing 908b may include any type of bearing that allows rotation in one angular direction but prevents rotation in the opposite direction. In at least one embodiment, the first one-way bearing 908a and the second one-way bearing 908b may be the same type of bearing, but are oppositely mounted so that the first capstan 808a and the second capstan 808b are alternately driven by opposite angular rotations of the input shaft 804.

[0069] Thus, the lower capstan 808b may be rotatably mounted to the input shaft 804 via the second one-way bearing 908b. In some embodiments, the second one-way bearing 908b may not be capable of rotating in the second angular direction 810b, but may be permitted to rotate in the first angular direction 810a. Thus, when the input shaft 804 rotates in the second angular direction 810b, the second one-way bearing 908b may be constrained against the input shaft 804 and transfer torque from the input shaft 804 to the lower capstan 808b, thereby driving the lower capstan 808b in the second angular direction 810b. As described above, rotating the lower capstan 808b in the second angular direction 810b may cause the fourth drive cable 608d ( Figure 6 and Figure 8 However, when the input shaft 804 is rotated in the first angular direction 810a, the second one-way bearing 908b can allow the lower capstan 808b to be rotationally disengaged from the input shaft 804 and allow free movement of the input shaft 804 to rotate relative to the lower capstan 808b.

[0070] The drive assembly 800 may also include a compliant member 920 that is operatively coupled to and extends between the upper capstan assembly 806a and the lower capstan assembly 806b. In the illustrated embodiment, the compliant member 920 includes a coil spring, but may alternatively include any other type of biasing device capable of transmitting torque. For example, the compliant member 920 may alternatively include a compression spring attached to each capstan assembly 806a, 806b using a cable. As shown, the compliant member 920 may have a first end or upper end 922a that can be engaged with the upper capstan assembly 806a and a second end or lower end 922b that can be engaged with the lower capstan assembly 806b. In some embodiments, the upper end 922a may be configured to be capable of engaging a receiving feature structure defined on the adapter 906 (see Fig.10 ) are engaged. However, in other embodiments, the receiving feature structure may alternatively form a part of the upper capstan 808a without departing from the scope of the present disclosure. Receiving the upper end 922a within the receiving feature structure can allow the compliant member 920 to transmit torque to the upper capstan assembly 806a, and more specifically to the upper capstan 808a.

[0071] The lower end 922b of the compliant member 920 can be coupled to the lower capstan 808b. More specifically, the lower end 922b can extend laterally and be received in a slot 924 defined in the lower capstan 808b. In at least one embodiment, when the drive assembly 800 is assembled, the bottom end of the upper capstan 808a can help retain the lower end 922b in the slot 924. Receiving the lower end 922b in the slot 924 can allow the compliant member 920 to transmit torque to the lower capstan assembly 806b, and more specifically to the lower capstan 808b.

[0072] Fig.10 is an exploded isometric view of a portion of a drive assembly 800 according to one or more embodiments. More specifically, Fig.10The bottom portion of the adapter 906 is shown. As described above, the adapter 906 may define a second mating structure 912b that can be mated with the first mating structure 912a of the upper capstan 808a. In addition, the adapter 906 may provide or define a receiver feature structure 1002 that is configured to receive the upper end 922a of the compliant member 920 and otherwise mate therewith. As shown, the receiver feature structure 1002 may include a hole or cavity sized to receive the upper end 922a, but may alternatively include a slot or the like. However, in an embodiment in which the adapter 906 is omitted, the receiver feature structure 1002 may alternatively be disposed on the upper capstan 808a, or the upper end 922a of the compliant member 920 may be directly coupled to the upper capstan 808a in other ways and may be capable of transmitting torque to the upper capstan assembly 806a.

[0073] See again FIG. 9A to FIG. 9B , the compliant member 920 can be configured to provide a constant amount of opposite torsional loads on the upper capstan assembly 806a and the lower capstan assembly 806b to help reduce the amount of cable slack that may be generated in the drive cable connected thereto. The compliant member 920 can be pre-tensioned during the assembly of the drive assembly 800, which causes the compliant member 920 to act on both the upper capstan assembly 806a and the lower capstan assembly 806b in opposite angular directions, thereby forcing the corresponding upper capstan 808a and the lower capstan 808b to rotate in the opposite direction. In some embodiments, the torque provided by the compliant member 920 can be set to be equal to or lower than the pre-tension limit of the cable attached to the upper capstan 808a and the lower capstan 808b. Therefore, if the tension in a given cable drops below the pre-tension value, the compliant member 920 will act on the corresponding capstan 808a, 808b, and cause the capstan 808a, 808b to rotate in the opposite direction and eliminate slack.

[0074] During exemplary operation, when the upper capstan 808a rotates to pull the first drive cable 608a ( Figure 6 and Figure 8 ), as described above, the fourth drive cable 608d ( Figure 6 and Figure 8) can relax. However, the torsional load provided by the compliant member 920 on the lower capstan 808b can cause the lower capstan 808b to rotate in the opposite direction and thereby help eliminate such slack in the fourth drive cable 608d. Conversely, when the lower capstan 808b rotates to pull the fourth drive cable 608d, as described above, the tension on the first drive cable 608a can relax, but the torsional load provided by the compliant member 920 on the upper capstan 808a can cause the upper capstan 808a to rotate in the opposite direction and thereby help eliminate any slack created in the first drive cable 608a. Therefore, this creates a very rigid system when tension is applied to the cables, and the system is therefore able to resist external loads applied during surgical procedures.

[0075] Still see FIG. 9A to FIG. 9B After the upper and lower capstan assemblies 806a, 806b are assembled on the input shaft 804, a locking ring 926 may be secured to the input shaft 804 at or near the upper end 902a to secure the capstan assemblies 806a, 806b to the input shaft 804. In some embodiments, the locking ring 926 may be sized to fit within an annular groove 928 ( Fig. 9B As will be appreciated, the locking ring 926 may be replaced with any device or mechanism that may suitably retain the upper and lower capstan assemblies 806a, 806b mounted to the input shaft 804 without departing from the scope of the present disclosure.

[0076] Embodiments disclosed herein include:

[0077] A. A surgical tool comprising: a drive housing having an elongated shaft extending therefrom; an end effector operatively coupled to a distal end of the elongated shaft; a drive input device and an input shaft rotatably mounted to the drive housing; a drive assembly mounted to the input shaft and comprising an upper capstan rotatably mounted to the input shaft using a first one-way bearing and a lower capstan rotatably mounted to the input shaft using a second one-way bearing; and a first drive cable and a second drive cable, the first drive cable coupled to the upper capstan The upper capstan is connected to the upper capstan and extends to the end actuator, the second drive cable is connected to the lower capstan and extends to the end actuator, wherein rotating the input shaft in a first angular direction rotationally disengages the lower capstan from the input shaft, and drives the upper capstan in the first angular direction to pull the first drive cable in a first linear direction, and wherein rotating the input shaft in a second angular direction opposite to the first angular direction rotationally disengages the upper capstan from the input shaft, and drives the lower capstan in the second angular direction to pull the second drive cable in a second linear direction opposite to the first linear direction.

[0078] B. A method for operating a surgical tool, comprising: positioning the surgical tool adjacent to a patient for operation, the surgical tool comprising: a drive housing and an end actuator, the drive housing having an elongated shaft extending therefrom, the end actuator being operably connected to the distal end of the elongated shaft; a drive input device and an input shaft, the drive input device and the input shaft being rotatably mounted to the drive housing; a drive assembly, the drive assembly being mounted to the input shaft and comprising an upper capstan that is rotatably mounted to the input shaft using a first one-way bearing and a lower capstan that is rotatably mounted to the input shaft using a second one-way bearing; and a first drive cable and a second drive cable, the first drive cable being connected to the upper capstan and extending to the end actuator, the second drive cable being connected to the lower capstan and extending to the end actuator. The method also includes: actuating the drive input device to rotate the input shaft in a first angular direction, thereby driving the upper capstan in the first angular direction to pull the first drive cable in a first linear direction; when the input shaft rotates in the first angular direction, the lower capstan is rotationally disengaged from the input shaft; actuating the drive input device to rotate the input shaft in a second angular direction opposite to the first angular direction, thereby driving the lower capstan in the second angular direction to pull the second drive cable in a second linear direction opposite to the first linear direction; and when the input shaft rotates in the second angular direction, the upper capstan is rotationally disengaged from the input shaft.

[0079] C. A drive assembly for a surgical tool, comprising: a first capstan assembly, the first capstan assembly including an upper capstan capable of being rotatably mounted to an input shaft of the surgical tool using a first one-way bearing; a lower capstan assembly, the lower capstan assembly including a lower capstan capable of being rotatably mounted to the input shaft using a second one-way bearing; a compliant member operatively connected to and extending between the upper capstan assembly and the lower capstan assembly, wherein the compliant member provides a constant opposite torsional load on the upper capstan assembly and the lower capstan assembly that forces the upper capstan and the lower capstan to rotate in opposite directions; and a first drive cable and a second drive cable, The first drive cable is capable of being fixed to the upper capstan and extending to the end actuator of the surgical instrument, and the second drive cable is capable of being fixed to the lower capstan and extending to the end actuator, wherein rotating the input shaft in a first angular direction rotationally disengages the lower capstan from the input shaft and drives the upper capstan in the first angular direction to pull the first drive cable in a first linear direction, and wherein rotating the input shaft in a second angular direction opposite to the first angular direction rotationally disengages the upper capstan from the input shaft and drives the lower capstan in the second angular direction to pull the second drive cable in a second linear direction opposite to the first linear direction.

[0080] Each of embodiments A, B, and C may have one or more of the following additional elements in any combination: Element 1: wherein rotating the input shaft in the first angular direction allows the second drive cable to unwind from the lower capstan and move in the second linear direction, and wherein rotating the input shaft in the second angular direction allows the first drive cable to unwind from the upper capstan and move in the first linear direction. Element 2: also includes a compliant member operatively coupled to and extending between the upper capstan and the lower capstan, wherein the compliant member provides a constant opposing torsional load on the upper capstan and the lower capstan that forces the upper capstan and the lower capstan to rotate in opposite directions. Element 3: wherein the compliant member is pre-tensioned during assembly to provide a torque equal to or below the pre-tension limit of the first drive cable and the second drive cable. Element 4: wherein the first one-way bearing is fixed to an adapter, and the adapter is capable of cooperating with the upper capstan such that rotation of the adapter correspondingly rotates the upper capstan. Element 5: wherein the adapter and the upper capstan each provide an interlocking feature structure capable of cooperating. Element 6: wherein the adapter defines a cavity sized to receive the first one-way bearing. Element 7: wherein the first one-way bearing is fixed to the upper capstan. Element 8: wherein the first one-way bearing and the second one-way bearing are selected from the group consisting of: a one-way clutch bearing, a wedge-type bearing, an anti-reverse bearing, a ratchet mechanism, and any combination thereof.

[0081] Element 9: Also includes: when the input shaft rotates in the first angular direction, allowing the second drive cable to unwind from the lower capstan and move in the second linear direction; and when the input shaft rotates in the second angular direction, allowing the first drive cable to unwind from the upper capstan and move in the first linear direction. Element 10: Also includes when the input shaft rotates in the first angular direction, winding a first length of the first drive cable onto the upper capstan and simultaneously unwinding a second length of the second drive cable from the lower capstan, wherein the first length and the second length are the same. Element 11: Also includes providing a constant opposite torsional load on the upper capstan and the lower capstan using a compliant member, the compliant member being operatively coupled to the upper capstan and the lower capstan and extending between the upper capstan and the lower capstan. Element 12: Also includes forcing the upper capstan and the lower capstan to rotate in opposite directions using the compliant member. Element 13: Also included is pre-tensioning the compliant member during assembly and thereby providing a torque equal to or below the pre-tension limit of the first drive cable and the second drive cable. Element 14: Wherein driving the upper capstan in the first angular direction also includes removing slack in the second drive cable by the compliant member acting on the lower capstan, and wherein driving the lower capstan in the second angular direction also includes removing slack in the first drive cable by the compliant member acting on the upper capstan.

[0082] Element 15: wherein rotating the input shaft in the first angular direction allows the second drive cable to unwind from the lower capstan and move in the second linear direction, and wherein rotating the input shaft in the second angular direction allows the first drive cable to unwind from the upper capstan and move in the first linear direction. Element 16: wherein the first capstan assembly further comprises an adapter capable of engaging with the upper capstan such that rotation of the adapter correspondingly rotates the upper capstan, and wherein the first one-way bearing is fixed to the adapter. Element 17: wherein the first one-way bearing and the second one-way bearing are selected from the group consisting of: a one-way clutch bearing, a wedge-type bearing, an anti-reverse bearing, a ratchet mechanism, and any combination thereof.

[0083] As non-limiting examples, exemplary combinations suitable for A, B, and C include: element 2 and element 3; element 4 and element 5; element 4 and element 6; element 9 and element 10; element 11 and element 12; element 11 and element 13; and element 11 and element 14.

[0084] Therefore, the system and method disclosed in the present invention are well suited to obtain the mentioned results and advantages as well as the results and advantages inherent therein. The specific embodiments disclosed above are exemplary only, because the teachings of the present disclosure can benefit from the teachings herein and be modified and implemented in different but equivalent ways that are obvious to those skilled in the art. In addition, there is no limitation on the details of the construction or design shown herein except as described in the following claims. It is therefore obvious that the specific exemplary embodiments disclosed above can be changed, combined or modified, and all such changes are considered to be within the scope of the present disclosure. The system and method disclosed illustratively herein can be appropriately implemented in the absence of any element not specifically disclosed herein and / or any optional element disclosed herein. Although the composition and method are described according to "including", "containing" or "comprising" various parts or steps, the composition and method can also be "essentially composed of various parts or steps" or "composed of various parts or steps". All numerical values ​​and ranges disclosed above can be changed by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any numerical value and any included range falling within the range are specifically disclosed. Specifically, each value range disclosed herein (in the form of "about a to about b" or the equivalent form "about a to b" or the equivalent form "from about ab") should be understood to list each numerical value and range covered within the broader value range. Moreover, the terms in the claims have their ordinary general meaning unless otherwise clearly and clearly defined by the patentee. In addition, the indefinite article "a" or "an" used in the claims is defined herein to mean one or more elements it introduces rather than one element. If there is any conflict in the use of words or terms in this specification and one or more patents or other documents that may be incorporated herein by reference, the definition consistent with this specification should be adopted.

[0085] As used herein, the phrase "at least one of" preceding a series of items (with the terms "and" or "or" separating any of the items) will modify the list as a whole, rather than each member of the list (i.e., each item). The phrase "at least one of" is permitted to mean at least one of any one of the items, and / or at least one of any combination of the items, and / or at least one of each of the items. As an example, the phrases "at least one of A, B, and C" or "at least one of A, B, or C" each refer to: only A, only B, or only C; any combination of A, B, and C; and / or at least one of each of A, B, and C.

Claims

1. A surgical tool comprising: a drive housing having an elongated shaft extending therefrom; an end effector operatively coupled to the distal end of the elongated shaft; a drive input and input shaft rotatably mounted to the drive housing; a drive assembly mounted to the input shaft and comprising an upper capstan rotatably mounted to the input shaft with a first one-way bearing and a lower capstan rotatably mounted to the input shaft with a second one-way bearing; a first drive cable coupled to the upper capstan and extending to the end effector and a second drive cable coupled to the lower capstan and extending to the end effector, and a compliant member operatively coupled to the upper and lower capstans and comprising a coil spring extending between the upper and lower capstans, wherein the coil spring provides a constant opposing torsional load on the upper and lower capstans that forces the upper and lower capstans to rotate in opposite directions, The input shaft comprises an elongated body constituting a rotation axis of the upper capstan and the lower capstan, wherein rotating the input shaft in a first angular direction rotationally disengages the lower capstan from the input shaft and drives the upper capstan in the first angular direction to pull the first drive cable in a first linear direction, and wherein rotating the input shaft in a second angular direction opposite to the first angular direction rotationally disengages the upper capstan from the input shaft, and driving the lower capstan in the second angular direction to pull the second drive cable in the first linear direction, the coil spring being wound around an axis parallel to the rotational axis, and the coil spring being housed within at least one of the upper capstan and the lower capstan.

2. The surgical tool according to claim 1, wherein: Rotating the input shaft in the first angular direction allows the second drive cable to unwind from the lower capstan and move in a second linear direction opposite the first linear direction, and wherein rotating the input shaft in the second angular direction allows the first drive cable to unwind from the upper capstan and move in the second linear direction.

3. The surgical tool according to claim 1, wherein: The compliant member is pre-tensioned during assembly to provide a torque that is equal to or less than a pre-tension limit of the first and second actuation cables.

4. The surgical tool according to claim 1, wherein: The first one-way bearing is fixed to an adapter, and the adapter is capable of cooperating with the upper capstan such that rotation of the adapter correspondingly rotates the upper capstan.

5. The surgical tool according to claim 4, wherein: The adapter and the upper capstan each provide mateable interlocking features.

6. The surgical tool according to claim 4, wherein: The adapter defines a cavity dimensioned to receive the first one-way bearing.

7. The surgical tool according to claim 1, wherein: The first one-way bearing is fixed to the upper capstan.

8. The surgical tool according to claim 1, wherein: The first one-way bearing and the second one-way bearing are selected from the group consisting of: a one-way clutch bearing, a sprag-type bearing, an anti-reverse bearing, a ratchet mechanism, and any combination thereof.

9. A drive assembly for a surgical tool, comprising: a first capstan assembly comprising an upper capstan rotatably mounted to an input shaft of the surgical tool using a first one-way bearing; a lower capstan assembly including a lower capstan rotatably mounted to the input shaft using a second one-way bearing; a compliant member operatively coupled to the upper and lower capstan assemblies and comprising a coil spring extending between the upper and lower capstan assemblies, wherein the coil spring provides a constant opposing torsional load on the upper and lower capstan assemblies that forces the upper and lower capstans to rotate in opposite directions; as well as a first drive cable and a second drive cable, the first drive cable being securable to the upper capstan and being extendable to an end effector of the surgical tool, the second drive cable being securable to the lower capstan and being extendable to the end effector, the input shaft comprising an elongated body constituting an axis of rotation of the upper capstan and the lower capstan, wherein rotating the input shaft in a first angular direction rotationally disengages the lower capstan from the input shaft and drives the upper capstan in the first angular direction to pull the first drive cable in a first linear direction, and wherein rotating the input shaft in a second angular direction opposite to the first angular direction rotationally disengages the upper capstan from the input shaft, and driving the lower capstan in the second angular direction to pull the second drive cable in the first linear direction, the coil spring being wound around an axis parallel to the rotational axis, and the coil spring being housed within at least one of the upper capstan and the lower capstan.

10. The drive assembly according to claim 9, wherein: Rotating the input shaft in the first angular direction allows the second drive cable to unwind from the lower capstan and move in a second linear direction opposite the first linear direction, and wherein rotating the input shaft in the second angular direction allows the first drive cable to unwind from the upper capstan and move in the second linear direction.

11. The drive assembly according to claim 9, wherein: The first winch assembly further includes an adapter capable of cooperating with the upper winch such that rotation of the adapter correspondingly rotates the upper winch, and wherein the first one-way bearing is fixed to the adapter.

12. The drive assembly according to claim 9, wherein: The first one-way bearing and the second one-way bearing are selected from the group consisting of: a one-way clutch bearing, a sprag-type bearing, an anti-reverse bearing, a ratchet mechanism, and any combination thereof.

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