Patent Description:
A common form of minimally invasive surgery is endoscopy, and a common form of endoscopy is laparoscopy, which is minimally invasive inspection and surgery inside the abdominal cavity. In standard laparoscopic surgery, a patient's abdomen is insufflated with gas, and cannula sleeves are passed through small (approximately one-half inch or less) incisions to provide entry ports for laparoscopic instruments.

The unit inch (") has the following conversion: <NUM> inch = <NUM>,<NUM>.

Laparoscopic surgical instruments generally include an endoscope (e.g., laparoscope) for viewing the surgical field and tools for working at the surgical site. The working tools are typically similar to those used in conventional (open) surgery, except that the working end or end effector of each tool is separated from its handle by an extension tube (also known as, e.g., an instrument shaft or a main shaft). The end effector can include, for example, a clamp, grasper, scissor, stapler, cautery tool, linear cutter, or needle holder.

To perform surgical procedures, the surgeon passes working tools through cannula sleeves to an internal surgical site and manipulates them from outside the abdomen. The surgeon views the procedure by means of a monitor that displays an image of the surgical site taken from the endoscope. Similar endoscopic techniques are employed in, for example, arthroscopy, retroperitoneoscopy, pelviscopy, nephroscopy, cystoscopy, cisternoscopy, sinoscopy, hysteroscopy, urethroscopy, and the like.

Minimally invasive telesurgical robotic systems are being developed to increase a surgeon's dexterity when working on an internal surgical site, as well as to allow a surgeon to operate on a patient from a remote location (outside the sterile field). In a telesurgery system, the surgeon is often provided with an image of the surgical site at a control console. While viewing a three dimensional image of the surgical site on a suitable viewer or display, the surgeon performs the surgical procedures on the patient by manipulating master input or control devices of the control console. Each of the master input devices controls the motion of a servo-mechanically actuated/articulated surgical instrument. During the surgical procedure, the telesurgical system can provide mechanical actuation and control of a variety of surgical instruments or tools having end effectors that perform various functions for the surgeon, for example, holding or driving a needle, grasping a blood vessel, dissecting tissue, or the like, in response to manipulation of the master input devices.

Non-robotic linear clamping, cutting and stapling devices have been employed in many different surgical procedures. For example, such a device can be used to resect a cancerous or anomalous tissue from a gastro-intestinal tract. Unfortunately, many known surgical devices, including known linear clamping, cutting and stapling devices, have opposing jaws that may generate less than a desired clamping force, which may reduce the effectiveness of the surgical device. Alternative devices may provide sufficient mechanical advantage to generate a desired level of clamping force for applicable surgical procedures (e.g., tissue stapling), but may have an actuation response rate that is less than desirable for telesurgical tissue manipulation. Furthermore, swapping tools having such high force jaw actuation mechanisms may be more complex (and potentially more prone to glitches) than would be ideal.

Thus, there is believed to be a need for tools with improved end effectors. Improved end effectors that provide sufficient clamping force, provide a fast response/low force articulation mode, and are at least partially back-drivable may also be desirable. Such tools may be beneficial in surgical applications, particularly in minimally invasive surgical applications.

<CIT> discloses a system for stapling tissue which comprises a flexible endoscope and an operative head including a pair of opposed, curved tissue clamping jaws sized to pass through an esophagus, the jaws being moveable with respect to one another between an open tissue receiving configuration and a closed tissue clamping configuration, a first one of the curved jaws including a stapling mechanism and a second one of the jaws including a staple forming anvil surface, the stapling mechanism including staple slots through which staples are fired arranged in a row extending from a proximal end of the first jaw to a distal end thereof in combination with a control handle which, when the operative head is in an operative position within one of a patient's stomach and esophagus, remains outside the patient, the control handle including a first actuator for moving the jaws relative to one another and a second actuator for operating the stapling mechanism.

<CIT> discloses a surgical instrument having a handle, barrel, and working end effector tip. The barrel is generally tubular with one end being releasably connected to the handle. The end effector is movably attached to the other end of the barrel, and may be positioned and operated independently through multiple linkage members connected to a motive power source housed in or attached to the handle. The instrument is operated and controlled by a microprocessor and multidimensional controller or electrical contacts included in the handle.

<CIT> discloses an electrosurgical medical device and technique for creating thermal welds in engaged tissue that provides very high compressive forces. The working end comprises five basic components, including (i) a handle portion coupled to an introducer sleeve member that carries paired first and second jaws members at it distal end; (ii) an actuatable elongate member that transitions distally to first and second extension portions that carry respective first and second slidable cam-type surfaces for engaging the paired jaws; (iii) a transverse member that is connected to the first and second extension portions for adjusting the transverse dimension between the first and second slidable cam surfaces to thereby control clamping pressure; (iv) a mechanism in the handle for actuating the elongate member to open and close the jaws; and (v) a mechanism in the handle for adjusting the transverse dimension between the first and second cam surfaces via the transverse member.

<CIT> discloses a surgical device that includes a jaw portion, having a first jaw in opposed correspondence with a second jaw, the second jaw including a surgical member. The surgical device may include a shaft portion coupled to a proximal end of the jaw portion and at least one motor configured to rotate the jaw portion relative to the shaft portion, to move the jaw portion relative to the shaft portion, move the first jaw relative to the second jaw and move the surgical member within the second jaw. The surgical member may be prevented from moving within the second jaw unless the first jaw is in a closed position relative to the second jaw.

<CIT> discloses a forceps, comprising: a pair of forceps members, being able to open or close at one end, so as to put an object between them, and being supported at the other end thereof; a driving wire for transferring tension thereon to the forceps members for bringing them to open and close; and a driver portion for giving the tension onto the driving wire, wherein: one of the forceps members is built up with a member (A), being able to open or close at one end, so as to put the object between them, while being supported to freely rotate at the other end, and the other member with a member (B), being able to put the object between them, but being supported fixedly at the other end; the driving wire is wound around a rotary portion at the other end of the member (A), and a portion of the wound portion thereof is fixed onto the rotary portion; and a tension for open and close operation is given from the driver portion to one end of the driving wire.

<CIT> discloses a robotically controlled surgical instrument that includes a first jaw and a second jaw used to grasp an item, and a drive mechanism that increases the force applied to the item grasped. The drive mechanism and the jaws can be provided with an accommodating mechanism that allows continued movement of the drive mechanism towards a locked position even after the jaws contact a larger item so that the drive mechanism can move to the locked position when grasping items of different sizes.

<CIT> discloses a medical manipulator that comprises a distal end working unit including a gripper as an end effector, an operating unit for operating the distal end working unit, a coupling interconnecting the distal end working unit and the operating unit, and an attitude changing mechanism for changing an attitude of the distal end working unit. When the operating unit is operated by an operator, the end effector is mechanically operated by a transmitting member. The attitude changing mechanism is operated by a bending drive source and a rotational drive source, which are operated when the operating unit is operated by the operator.

The invention is defined in the independent claim and other embodiments are listed in the dependent claims. No methods are claimed.

Improved end effectors, related tools, and related methods are described. In many surgical applications, for example, many minimally invasive surgical applications, the size of a surgical tool end effector is substantially constrained by applicable space constraints. While such a size constraint mitigates in favor of the use of one actuation mechanism, in many embodiments, the disclosed end effectors use two independent mechanisms to articulate a jaw of the end effector. In many embodiments, a first actuation mechanism provides a fast response/low force mode that varies the position of the articulated jaw between a clamped configuration and an open configuration. In many embodiments, the first actuation mechanism is back-drivable. In some examples, a second actuation mechanism provides a high clamping force mode that has a first configuration where the articulated jaw is held in a clamped configuration and a second configuration where the articulated jaw is unconstrained by the second actuation mechanism. In some examples, the second actuation mechanism is non-back-drivable.

Such end effectors, tools, and methods provide a number of benefits, particularly with respect to minimally invasive surgical applications. For example, in some examples, the high clamping force articulation mode enables proper tissue compression and resists jaw motion, for example, during staple firing. In some examples, the fast response/low force mode is useful for manipulating tissue, is useful for finding a more optimum tissue purchase, and provides a more responsive articulation of the articulated jaw. In some examples, a back-drivable first actuation mechanism permits the articulated jaw to move upon heavy contact with patient tissue, which may help to avoid injuring the patient tissue, and/or permits the articulated jaw to close upon contact with a cannula sleeve, which may aid in the removal of the surgical tool from the patient. Additionally, the disclosed end effectors may provide for improved tissue gap and/or tissue compression sensing because the redundant actuation mechanisms may provide additional feedback data for analysis and, in some examples, the first actuation mechanism can be made to function efficiently with low frictional losses, which may improve sensing capability. While the various examples disclosed herein are primarily described with regard to surgical applications, these surgical applications are merely example applications, and the disclosed end effectors, tools, and methods can be used in other suitable applications, both inside and outside a human body, as well as in non- surgical applications.

In an example, a minimally invasive surgical method is provided. The method includes introducing a jaw of a tool to an internal surgical site within a patient through a minimally invasive aperture or natural orifice, manipulating tissue at the internal surgical site with a grasping force by articulating the jaw with a first actuation mechanism, and treating a target tissue at the internal surgical site using a clamping force by articulating the jaw of the tool with a second actuation mechanism. The first and second actuation mechanisms extend along a shaft from outside the patient to the jaw. The clamping force is greater than the grasping force.

In some examples, the first actuation mechanism comprises cable segments and the second actuation mechanism comprises a drive shaft. In some examples, the manipulation of the tissue is performed by closing the jaw using tension in a first cable segment and by opening the jaw using tension in a second cable segment. In some examples, the treatment of the tissue is performed by closing the jaw using a rotation of the drive shaft within the shaft of the tool. In some examples, the second actuation mechanism back-drives the first mechanism such that articulation of the second actuation mechanism to close the jaw will drive the cable segments toward a closed jaw configuration and articulation of the second actuation mechanism toward an open jaw configuration will not back-drive the first mechanism or open the jaw if the cable segments remain in a closed jaw configuration.

In an aspect, there is provided a surgical instrument comprising:.

The first actuation mechanism can include one or more additional components and/or have one or more additional characteristics. For example, in some examples, the first actuation mechanism is back-drivable. In some examples, the first actuation mechanism includes cables. In some examples, a pulling movement of a first cable segment of the first actuation mechanism moves the jaw towards the open configuration and a pulling movement of a second cable segment of the first actuation mechanism moves the jaw towards the clamped configuration. The first actuation mechanism can include a first linkage coupling the first cable segment with the jaw and the tool body. The first actuation mechanism can include a second linkage coupling the second cable segment with the jaw and the tool body.

The second actuation mechanism can include one or more additional components and/or have one or more additional characteristics. For example, in some examples, the second actuation mechanism is non-back-drivable. The second actuation mechanism can be operable to produce a clamping force between the jaw and the tool body of at least <NUM> lbs. In some examples, the second actuation mechanism includes a leadscrew. The second actuation mechanism can include a leadscrew driven cam operatively coupled with the leadscrew and the jaw can include an interfacing cam surface for contact with the leadscrew driven cam.

The unit pound has the following conversion: <NUM> lbs = <NUM>,<NUM> or <NUM> = <NUM> lbs.

The surgical tool can include one or more additional components. For example, the surgical tool can further include an actuated device. For example, the actuated device can be a cutting device, a stapling device, or a cutting and stapling device.

In another example, a robotic tool is provided for mounting on a manipulator having a first drive. The robotic tool includes a proximal tool chassis releasably mountable to the manipulator; a drive motor coupled with the tool chassis and disposed adjacent the tool chassis; a distal end effector comprising a movable jaw; an instrument shaft having a proximal end adjacent the chassis, and a distal end adjacent the end effector; a first actuation mechanism coupling the first drive to the end effector when the chassis is mounted to the manipulator so as to articulate the end effector between an open configuration and a clamped configuration; and a second actuation mechanism coupling the drive motor to the end effector so as to articulate the end effector into the clamped configuration from the open configuration.

The first actuation mechanism can include one or more additional components and/or have one or more additional characteristics. For example, in some examples, the first actuation mechanism is back-drivable. The first actuation mechanism can include cables extending from the chassis distally within a bore of the instrument shaft operatively coupling the end effector to the first drive.

The second actuation mechanism can include one or more additional components and/or have one or more additional characteristics. For example, in some examples, the second actuation mechanism is non-back-drivable. The second actuation mechanism can include a leadscrew driven cam. The second actuation mechanism can have a first configuration where the jaw is held in the clamped configuration and a second configuration where the position of the jaw relative to the tool body is unconstrained by the second actuation mechanism. The second actuation mechanism can include a drive shaft mounted for rotation within a bore of the instrument shaft and operatively coupling the end effector to the drive motor.

In another example, a surgical instrument is provided. The surgical instrument includes an end effector comprising a movable jaw, a first jaw actuation mechanism coupled to the movable jaw, and a second jaw actuation mechanism coupled to the moveable jaw. The first jaw actuation mechanism moves the jaw from an open position to a closed position independently of the second jaw actuation mechanism. The second jaw actuation mechanism moves the jaw from the open position to the closed position independently of the first jaw actuation mechanism.

The second jaw mechanism can constrain the range of motion in which the first actuation mechanism can move the jaw. For example, the second actuation mechanism can have a first configuration in which the movable jaw is held in a clamped position and in which the first actuation mechanism is prevented from moving the movable jaw.

The first actuation mechanism can provide a fast response/low force articulation mode, and the second actuation mechanism can provide a high clamping force mode. For example, in some examples, the maximum clamping force of the movable jaw provided by the second actuation mechanism is larger that a maximum clamping force provided by the first actuation mechanism.

The first and second actuation mechanisms can employ different force transmission mechanisms. For example, a force used by the first jaw actuation mechanism to move the jaw from the open to the close position can include a linear force, and a force used by the second jaw actuation mechanism to move the jaw from the open to the closed position can include a torque. In some examples, the first jaw actuation mechanism includes a cable-driven mechanism. In some examples, the second jaw actuation mechanism includes a leadscrew-driven mechanism.

For a fuller understanding of the nature and advantages of the present invention, reference should be made to the ensuing detailed description and accompanying drawings. Other aspects, objects and advantages of the invention will be apparent from the drawings and detailed description that follows.

Improved end effectors, related tools, and related methods are disclosed. In some examples, the disclosed end effectors use two independent mechanisms to articulate a jaw of the end effector. In some examples, a first actuation mechanisms provides a fast response/low force mode that varies the position of the articulated jaw between a clamped configuration and an open configuration. In ma some examples, the first actuation mechanism is back-drivable. The first actuation mechanism can be designed to provide, for example, <NUM> lbs of clamping force at the tip of the articulated jaw of the end effector. In some examples, a second actuation mechanism provides a high clamping force mode that has a first configuration where the articulated jaw is held in a clamped configuration and a second configuration where the articulated jaw is unconstrained by the second actuation mechanism. In some examples, the second actuation mechanism is non-back-drivable. In some examples, the second actuation mechanism converts a relatively weak force or torque (but with large displacement available) to a relatively high torque rotating the jaw of the end effector. The second actuation mechanism can be designed to provide, for example, <NUM> pounds of clamping force at the tip of the articulated jaw of the end effector. The disclosed end effectors, tools, and methods can be used in a variety of applications, and may be particularly beneficial when used in minimally invasive surgery applications. While the various examples disclosed herein are primarily described with regard to surgical applications, these surgical applications are merely example applications, and the disclosed end effectors, tools, and methods can be used in other suitable applications, both inside and outside a human body, as well as in non-surgical application. The unit pound has the following conversion: <NUM> = <NUM> pounds.

Referring now to the drawings, in which like reference numerals represent like parts throughout the several views, <FIG> is a plan view illustration of a Minimally Invasive Robotic Surgical (MIRS) system <NUM>, typically used for performing a minimally invasive diagnostic or surgical procedure on a Patient <NUM> who is lying down on an Operating table <NUM>. The system can include a Surgeon's Console <NUM> for use by a Surgeon <NUM> during the procedure. One or more Assistants <NUM> may also participate in the procedure. The MIRS system <NUM> can further include a Patient Side Cart <NUM> (surgical robot), and an Electronics Cart <NUM>. The Patient Side Cart <NUM> can manipulate at least one removably coupled tool assembly <NUM> (hereinafter simply referred to as a "tool") through a minimally invasive incision in the body of the Patient <NUM> while the Surgeon <NUM> views the surgical site through the Console <NUM>. An image of the surgical site can be obtained by an endoscope <NUM>, such as a stereoscopic endoscope, which can be manipulated by the Patient Side Cart <NUM> so as to orient the endoscope <NUM>. The Electronics Cart <NUM> can be used to process the images of the surgical site for subsequent display to the Surgeon <NUM> through the Surgeon's Console <NUM>. The number of surgical tools <NUM> used at one time will generally depend on the diagnostic or surgical procedure and the space constraints within the operating room among other factors. If it is necessary to change one or more of the tools <NUM> being used during a procedure, an Assistant <NUM> may remove the tool <NUM> from the Patient Side Cart <NUM>, and replace it with another tool <NUM> from a tray <NUM> in the operating room.

<FIG> is a perspective view of the Surgeon's Console <NUM>. The Surgeon's Console <NUM> includes a left eye display <NUM> and a right eye display <NUM> for presenting the Surgeon <NUM> with a coordinated stereo view of the surgical site that enables depth perception. The Console <NUM> further includes one or more input control devices <NUM>, which in turn cause the Patient Side Cart <NUM> (shown in <FIG>) to manipulate one or more tools. The input control devices <NUM> will provide the same degrees of freedom as their associated tools <NUM> (shown in <FIG>) so as to provide the Surgeon with telepresence, or the perception that the input control devices <NUM> are integral with the tools <NUM> so that the Surgeon has a strong sense of directly controlling the tools <NUM>. To this end, position, force, and tactile feedback sensors (not shown) may be employed to transmit position, force, and tactile sensations from the tools <NUM> back to the Surgeon's hands through the input control devices <NUM>.

The Surgeon's Console <NUM> is usually located in the same room as the patient so that the Surgeon may directly monitor the procedure, be physically present if necessary, and speak to an Assistant directly rather than over the telephone or other communication medium. However, the Surgeon can be located in a different room, a completely different building, or other remote location from the Patient allowing for remote surgical procedures (i.e., operating from outside the sterile field).

<FIG> is a perspective view of the Electronics Cart <NUM>. The Electronics Cart <NUM> can be coupled with the endoscope <NUM> and can include a processor to process captured images for subsequent display, such as to a Surgeon on the Surgeon's Console, or on any other suitable display located locally and/or remotely. For example, where a stereoscopic endoscope is used, the Electronics Cart <NUM> can process the captured images so as to present the Surgeon with coordinated stereo images of the surgical site. Such coordination can include alignment between the opposing images and can include adjusting the stereo working distance of the stereoscopic endoscope. As another example, image processing can include the use of previously determined camera calibration parameters so as to compensate for imaging errors of the image capture device, such as optical aberrations.

<FIG> diagrammatically illustrates a robotic surgery system <NUM> (such as MIRS system <NUM> of <FIG>). As discussed above, a Surgeon's Console <NUM> (such as Surgeon's Console <NUM> in <FIG>) can be used by a Surgeon to control a Patient Side Cart (Surgical Robot) <NUM> (such as Patent Side Cart <NUM> in <FIG>) during a minimally invasive procedure. The Patient Side Cart <NUM> can use an imaging device, such as a stereoscopic endoscope, to capture images of the procedure site and output the captured images to an Electronics Cart <NUM> (such as the Electronics Cart <NUM> in <FIG>). As discussed above, the Electronics Cart <NUM> can process the captured images in a variety of ways prior to any subsequent display. For example, the Electronics Cart <NUM> can overlay the captured images with a virtual control panel interface prior to displaying the combined images to the Surgeon via the Surgeon's Console <NUM>. The Patient Side Cart <NUM> can output the captured images for processing outside the Electronics Cart <NUM>. For example, the Patient Side Cart <NUM> can output the captured images to a processor <NUM>, which can be used to process the captured images. The images can also be processed by a combination the Electronics Cart <NUM> and the processor <NUM>, which can be coupled together so as to process the captured images jointly, sequentially, and/or combinations thereof. One or more separate displays <NUM> can also be coupled with the processor <NUM> and/or the Electronics Cart <NUM> for local and/or remote display of images, such as images of the procedure site, or any other related images.

<FIG> show a Patient Side Cart <NUM> and a surgical tool <NUM>, respectively. The surgical tool <NUM> is an example of the surgical tools <NUM>. The Patient Side Cart <NUM> shown provides for the manipulation of three surgical tools <NUM> and an imaging device <NUM>, such as a stereoscopic endoscope used for the capture of images of the site of the procedure. Manipulation is provided by robotic mechanisms having a number of robotic joints. The imaging device <NUM> and the surgical tools <NUM> can be positioned and manipulated through incisions in the patient so that a kinematic remote center is maintained at the incision so as to minimize the size of the incision. Images of the surgical site can include images of the distal ends of the surgical tools <NUM> when they are positioned within the field-of-view of the imaging device <NUM>.

In some examples, two independent actuation mechanisms are used to control the articulation of an articulated jaw of an end effector. A first actuation mechanism can be used to provide a fast response/low force mode, and a second actuation mechanism can be used to provide a high clamping force mode. In some examples, the first actuation mechanism used to provide the fast response/low force articulation mode is back-drivable. In some examples, the second actuation mechanism used to provide the high clamping force articulation mode is non-back-drivable. Such use of two independent actuation mechanisms may be beneficial in some surgical applications, for example, electrocautery sealing, stapling, etc., that may require multiple low force jaw placement clampings before a high force jaw clamping is used to carry out the surgical tool's task.

In some examples, the fast response/low force mode is provided by a cable actuation mechanism that includes a pair of pull cables. In some examples, a pulling motion of a first cable of the pair articulates the articulated jaw towards a closed (clamped) configuration and a pulling motion of a second cable of the pair articulates the articulated jaw towards an open configuration. In some examples, the cable actuation mechanism is back-drivable.

In some examples, the high clamping force mode is provided by a leadscrew actuation mechanism that includes a leadscrew driven cam. The driven cam interfaces with a mating cam surface on the articulated jaw so as to hold the articulated jaw in a clamped configuration when the leadscrew driven cam is at a first end of its range of motion. In addition, the driven cam does not constrain motion of the articulated jaw when the leadscrew driven cam is at a second end (opposite end) of its range of motion. In other words, the mating cam surfaces are arranged such that motion of the leadscrew driven cam in one direction will cause the articulated jaw to close, and motion of the leadscrew driven cam in the reverse direction will allow (but not force) the articulated jaw to open to a limit provided by the cam surfaces. In some examples, the leadscrew actuation mechanism is non-back-drivable.

<FIG> is a perspective view of an end effector <NUM> having a jaw <NUM> articulated by two independent actuation mechanisms, in accordance with some examples. The end effector <NUM> includes an end effector base <NUM>, the articulated jaw <NUM>, and a detachable stationary jaw <NUM>. The end effector <NUM> is actuated via a first drive shaft <NUM>, a second drive shaft <NUM>, and two actuation cables (not shown). The first drive shaft <NUM> rotates a leadscrew <NUM> of a leadscrew actuation mechanism. The second drive shaft <NUM> rotates another leadscrew (not shown) of the detachable stationary jaw <NUM>.

In some examples, the first drive shaft <NUM> and/or the second drive shaft <NUM> are driven by drive features located in a proximal tool chassis to which the end effector <NUM> is coupled with via an instrument shaft. In many embodiments, the proximal tool chassis is configured to be releasably mountable to a robotic tool manipulator. In some examples, the first drive shaft <NUM> and the second drive shaft <NUM> are actuated via respective drive features located in the proximal tool chassis. In some examples, such drive features are driven by motors that are located in the proximal tool chassis.

<FIG> is a perspective view of the end effector <NUM> of <FIG> (with the articulated jaw <NUM> removed to better illustrate components of the leadscrew actuation mechanism), in accordance with some examples. The leadscrew <NUM> is mounted for rotation relative to the end effector base <NUM>. A leadscrew driven cam <NUM> is coupled with the leadscrew <NUM> so that selective rotation of the leadscrew <NUM> can be used to selectively translate the leadscrew driven cam <NUM> along a cam slot <NUM> in the end effector base <NUM>. The end effector <NUM> includes a pivot pin <NUM> that is used to rotationally couple the articulated jaw <NUM> with the end effector base <NUM>.

<FIG> illustrate the leadscrew actuation mechanism of <FIG>. The leadscrew <NUM> has a distal journal surface <NUM> and a proximal journal surface that interfaces with a proximal bearing <NUM>. In some examples, the distal journal surface <NUM> is received within a cylindrical receptacle located at the distal end of the cam slot <NUM>. Such a distal support for the leadscrew <NUM> can be configured to keep the leadscrew <NUM> from swinging excessively, and with relatively large clearance(s) between the distal journal surface <NUM> and the cylindrical receptacle. The proximal bearing <NUM> is supported by the end effector base <NUM> so as to support the proximal end of the leadscrew <NUM>. The proximal bearing <NUM> can be a ball bearing, which may help to reduce friction and wear. A distal bearing (not shown) can be supported by the end effector base <NUM> so as to support the distal end of the leadscrew <NUM>, and the distal bearing can be a ball bearing. The leadscrew driven cam <NUM> includes a threaded bore configured to mate with the external threads of the leadscrew <NUM>. The leadscrew driven cam <NUM> includes top and bottom surfaces configured to interact with corresponding top and bottom surfaces of the cam slot <NUM>. The interaction between leadscrew driven cam <NUM> and the cam slot <NUM> prevents the leadscrew driven cam <NUM> from rotating relative to the cam slot <NUM>, which causes the leadscrew driven cam <NUM> to translate along the cam slot <NUM> in response to rotation of the leadscrew.

The articulated jaw <NUM> includes mating cam surfaces <NUM> that are configured so that the position of the leadscrew driven cam <NUM> along the cam slot <NUM> determines the extent to which the rotational motion of the articulated jaw <NUM> around the pivot pin <NUM> is constrained by the leadscrew driven cam <NUM>. The articulated jaw <NUM> includes a first proximal side <NUM> and a second proximal side <NUM> that are separated by a central slot. The first and second proximal sides are disposed on opposing sides of the end effector base <NUM> when the articulated jaw <NUM> is coupled with the end effector base <NUM> via the pivot pin <NUM>. Each of the first and second proximal sides <NUM>, <NUM> includes a recessed area defining a mating cam surface <NUM> and providing clearance between the leadscrew driven cam <NUM> and the proximal sides <NUM>, <NUM>. When the leadscrew driven cam <NUM> is positioned at or near the proximal end of the cam slot <NUM> (near its position illustrated in <FIG>), contact between the leadscrew driven cam <NUM> and the mating cam surfaces <NUM> of the articulated jaw <NUM> hold the articulated jaw in a clamped configuration. When the leadscrew driven cam <NUM> is positioned at the distal end of the cam slot <NUM>, the rotational position of the articulated jaw around the pivot pin <NUM> is unconstrained by the leadscrew driven cam <NUM> for a range of rotational positions between a clamped configuration (where there is a gap between the leadscrew driven cam <NUM> and the mating cam surfaces <NUM> of the articulated jaw <NUM>) and an open configuration (where there may or may not be a gap between the leadscrew driven cam <NUM> and the mating cam surfaces <NUM> of the articulated jaw <NUM>). For positions of the leadscrew driven cam <NUM> in between the proximal and distal ends of the cam slot <NUM>, the range of unconstrained motion can vary according to the cam surfaces used.

The use of a recess in each of the proximal sides <NUM>, <NUM> to define the mating cam surfaces <NUM> of the articulated jaw <NUM> provides a number of benefits. For example, the use of recesses as opposed to traverse slots that extend through the proximal sides provides a continuous outside surface to the proximal sides <NUM>, <NUM> of the articulated jaw, which is less likely to snag on patient tissue than would a traverse slot opening. The absence of traverse slots also helps to stiffen the proximal sides <NUM>, <NUM> as compared to proximal sides with traverse slots, and therefore provides increased clamping stiffness. Such proximal sides <NUM>, <NUM> may have increased stiffness in two planes, which may help maintain alignment of the articulated jaw <NUM> in the presences of external forces. Such increased stiffness in two planes may be beneficial in some surgical applications, for example, in tissue stapling where it is beneficial to maintain alignment between the staples and anvil pockets that form the staples. Further, the use of recesses instead of traverse slots also provides an actuation mechanism that is less likely to be jammed by extraneous material as compared to one having proximal sides with open traverse slots.

The leadscrew actuation mechanism can be configured to provide a desired clamping force between the articulated jaw and an opposing jaw of the end effector. For example, in some examples, the leadscrew actuation mechanism is configured to provide at least <NUM> lbs of clamping force at the tip of the articulated jaw <NUM> (approximately <NUM> inches from the pivot pin <NUM>). In many embodiments, the leadscrew actuation mechanism is configured to provide at least <NUM> lbs of clamping force at the tip of the articulated jaw <NUM>. In some examples, to produce <NUM> lbs of clamping force at the tip of the articulated jaw <NUM>, the input torque to the leadscrew <NUM> is approximately <NUM> N m and the leadscrew <NUM> has <NUM> turns.

The leadscrew actuation mechanism can be fabricated using available materials and components. For example, many components of the leadscrew actuation mechanism can be fabricated from an available stainless steel(s). The leadscrew driven cam <NUM> can be coated (e.g., TiN) to reduce friction against the surfaces it rubs against (e.g., leadscrew <NUM>; end effector base <NUM>; proximal sides <NUM>, <NUM> of the articulated jaw <NUM>). Stranded cables can be used to drive the first actuation mechanism.

<FIG> illustrate components of a cable actuation mechanism <NUM>, in accordance with some examples. As described above, the leadscrew driven cam <NUM> can be positioned at the distal end of the cam slot <NUM> (i.e., near the pivot pin <NUM>). For such a distal position of the leadscrew driven cam <NUM>, as discussed above, the rotational position of the articulated jaw <NUM> about the pivot pin <NUM> is unconstrained for a range of rotational positions of the articulated jaw <NUM>. Accordingly, the rotational position of the articulated jaw <NUM> about the pivot pin <NUM> can be controlled by the cable actuation mechanism <NUM>. The cable actuation mechanism <NUM> is operable to vary the rotational position of the articulated jaw between the clamped configuration and the open configuration. The cable actuation mechanism <NUM> includes a pair of pull cables <NUM>, <NUM>. The cable actuation mechanism <NUM> also includes a first linkage <NUM> that is used to rotate the articulated jaw <NUM> about the pivot pin <NUM> towards the clamped configuration, and an analogous second linkage <NUM> that is used to rotate the articulated jaw <NUM> about the pivot pin <NUM> towards the open configuration. The first linkage <NUM> (shown in <FIG>) includes a rotary link <NUM> that is mounted for rotation relative to the end effector base <NUM> via a pivot pin <NUM>. A connecting link <NUM> couples the rotary link <NUM> to the articulated jaw <NUM> via a pivot pin <NUM> and a pivot pin <NUM>. The first linkage <NUM> is articulated via a pulling motion of the pull cable <NUM>. In operation, a pulling motion of the pull cable <NUM> rotates the rotary link <NUM> in a clockwise direction about the pivot pin <NUM>. The resulting motion of the connecting link <NUM> rotates the articulated jaw <NUM> in a counter-clockwise direction about the pivot pin <NUM> towards the clamped configuration.

The second linkage <NUM> (shown in <FIG>) of the cable actuation mechanism <NUM> includes analogous components to the first linkage <NUM>, for example, a rotary link <NUM> mounted for rotation relative to the end effector base <NUM> via a pivot pin <NUM>, and a connecting link <NUM> that couples the rotary link <NUM> to the articulated jaw <NUM> via two pivot pins <NUM>, <NUM>. The second linkage <NUM> is articulated via a pulling motion of the pull cable <NUM>. The second linkage <NUM> is configured such that a pulling motion of the pull cable <NUM> rotates the articulated jaw <NUM> about the pivot pin <NUM> towards the open configuration. In many embodiments, the pivot pin <NUM> between the connecting link <NUM> and the rotary link <NUM> of the second linkage <NUM> is <NUM> degrees out of phase with the pivot pin <NUM> between the connecting link <NUM> and the rotary link <NUM> of the first linkage <NUM>. Coordinated pulling and extension of the pull cables <NUM>, <NUM> of the cable actuation mechanism <NUM> is used to articulate the articulated jaw <NUM> between the open and clamped configurations. In order to best provide equal and opposite cable motion (and thereby maintain cable tension in a capstan-driven system described below), a common rotational axis for the pivot pins <NUM>, <NUM> is configured to lie on a plane that contains the rotational axes for pivot pins <NUM>, <NUM> when the articulated jaw <NUM> is closed (or nearly closed) and again when the when the articulated jaw <NUM> is open (or nearly open). The connecting links <NUM>, <NUM> are assembled symmetrically opposite about this same plane for the first and second linkages <NUM>, <NUM>. The distance between the pivot pins <NUM>, <NUM> and between the pivot pins <NUM>, <NUM> is the same for both the first and second linkages <NUM>, <NUM>, and the distance between the pivot pins <NUM>, <NUM> and between the pivot pins <NUM>, <NUM> is the same for both the first and second linkages <NUM>, <NUM>.

<FIG> illustrate an articulation of the articulated jaw <NUM> via another cable actuation mechanism <NUM>, in accordance with some examples. In example <NUM> of the cable actuation mechanism, a first pull cable <NUM> and a second pull cable <NUM> are directly coupled with the proximal end of the articulated jaw <NUM>. The first pull cable <NUM> wraps around a first pulley <NUM> so that a pulling motion of the first pull cable <NUM> rotates the articulated jaw <NUM> about the pivot pin <NUM> towards the clamped configuration. The second pull cable <NUM> wraps around a second pulley <NUM> so that a pulling motion of the second pull cable <NUM> rotates the articulated jaw <NUM> about the pivot pin <NUM> towards the open configuration. Accordingly, coordinated pulling and extension of the first and second pull cables of the cable actuation mechanism <NUM> is used to articulate the articulated jaw <NUM> between the open and clamped configurations. In order to best provide equal and opposite cable motion (and thereby maintain cable tension in the capstan-driven system described below), the radius of the arc prescribed by cable <NUM> about the pivot <NUM> is substantially the same as the radius prescribed by cable <NUM> about the pivot <NUM>.

In some examples, the cable (i.e., low force) actuation mechanism comprises a pair of pull cables that are actuated via an actuation feature disposed in a proximal tool chassis. The proximal tool chassis can be configured to be releasably mountable to a robotic tool manipulator having a drive mechanism that operatively couples with the actuation feature. For example, the pair of pull cables can be wrapped around a capstan located in the proximal tool chassis. The capstan can be operatively coupled with a capstan drive servo motor of the robotic tool manipulator when the proximal tool chassis is mounted to the robotic tool manipulator. Selective rotation of the capstan drive motor can be used to produce a corresponding rotation of the capstan. Rotation of the capstan can be used to produce a coordinated extension and retraction of the pull cables. As discussed above, coordinated actuation of the pull cables can be used to produce a corresponding articulation of the articulated jaw of the end effector.

In some examples, the fast response/low force mode is provided by a cable actuation mechanism that is back-drivable. For example, an external force applied to the articulated jaw can be used to rotate the articulated jaw towards the clamped configuration and back-drive the cable actuation mechanism. With a cable actuation mechanism that comprises a pair of pull cables wrapped around a capstan, an external force that rotates the articulated jaw towards the clamped configuration produces an increase in tension in one of the pull cables and a decrease in tension in the other pull cable, thereby causing the capstan to rotate in response. As is known, such a cable driven system can be configured to have sufficient efficiency for back-drivability. Likewise, an external force applied to the articulated jaw can be used to rotate the articulated jaw towards the open configuration and back-drive the cable actuation mechanism. As discussed above, a back-drivable fast response/low force actuation mechanism provides a number of benefits.

Alternate mechanisms can be used to provide a fast response/low force articulation mode. For example, an actuation mechanism comprising push/pull rods can be used.

<FIG> is a cross-sectional view illustrating components of the above discussed leadscrew actuation mechanism. The illustrated components include the leadscrew <NUM>, the leadscrew driven cam <NUM>, the cam slot <NUM> in the end effector base <NUM>, the distal journal surface <NUM>, the cylindrical receptacle <NUM> in the end effector base, and the proximal bearing <NUM> supported by the end effector base <NUM>.

<FIG> is a simplified perspective view diagrammatic illustration of a tool assembly <NUM>, in accordance with some examples. The tool assembly <NUM> includes a proximal actuation mechanism <NUM>, an elongate shaft <NUM> having a proximal end and a distal end, a tool body <NUM> disposed at the distal end of the shaft, a jaw <NUM> movable relative to the tool body <NUM> between a clamped configuration and an open configuration, a first actuation mechanism coupled with the jaw, and a second actuation mechanism coupled with the jaw. The first actuation mechanism is operable to vary the position of the jaw relative to the tool body between the clamped configuration and the open configuration. The second actuation mechanism has a first configuration where the jaw is held in the clamped configuration and a second configuration where the position of the jaw relative to the tool body is unconstrained by the second actuation mechanism. The first actuation mechanism is operatively coupled with the proximal actuation mechanism. In many embodiments, the first actuation mechanism comprises a pair of pull cables that are actuated by the proximal actuation mechanism. The second actuation mechanism is operatively coupled with the proximal actuation mechanism. In many embodiments, the second actuation mechanism includes a leadscrew driven cam located in the tool body that is driven by the proximal actuation mechanism via a drive shaft extending through the elongate shaft <NUM> from the proximal actuation mechanism.

The tool assembly <NUM> can be configured for use in a variety of applications. For example, the tool assembly <NUM> can be configured as a hand held device with manual and/or automated actuation used in the proximal actuation mechanism. The tool assembly <NUM> can also be configured for use in surgical applications, for example, electrocautery sealing, stapling, etc. The tool assembly <NUM> can have applications beyond minimally invasive robotic surgery, for example, non-robotic minimally invasive surgery, non-minimally invasive robotic surgery, non-robotic non-minimally invasive surgery, as well as other applications where the use of the disclosed redundant jaw actuation would be beneficial.

Redundant jaw actuation can be used to articulate a jaw of a robotic tool end effector. For example, <FIG> schematically illustrates a robotic tool <NUM> employing redundant jaw actuation. The robotic tool <NUM> includes a proximal tool chassis <NUM>, a drive motor <NUM>, an instrument shaft <NUM>, a distal end effector <NUM>, a first actuation mechanism portion <NUM>, and a second actuation mechanism <NUM>. The distal end effector <NUM> comprises an articulated jaw <NUM>. The proximal tool chassis <NUM> is releasably mountable to a robotic tool manipulator <NUM> having a first drive <NUM>, and a first actuation mechanism portion <NUM> that operatively couples with the first actuation mechanism portion <NUM> of the robotic tool <NUM> when the proximal tool chassis <NUM> is mounted to the robotic tool manipulator <NUM>. The instrument shaft <NUM> has a proximal end adjacent the tool chassis <NUM>, and a distal end adjacent the end effector <NUM>. The first actuation mechanism (comprising portion <NUM> and portion <NUM>) couples the first drive <NUM> to the articulated jaw <NUM> when the tool chassis <NUM> is mounted to the tool manipulator <NUM> so as to articulate the end effector <NUM> between an open configuration and a clamped configuration. The second actuation mechanism <NUM> couples the drive motor <NUM> to the articulated jaw <NUM> so as to articulate the end effector into the clamped configuration from the open configuration. The first actuation mechanism can be a cable actuation mechanism, for example, an above discussed cable actuation mechanism that provides the fast response/low force mode. In many embodiments, the first actuation mechanism is back-drivable. The second actuation mechanism can include a drive shaft that couples the drive motor <NUM> with a leadscrew actuation mechanism, for example, an above discussed leadscrew actuation mechanism that provides the high clamping force mode. In many embodiments, the second actuation mechanism is non-back-drivable.

Claim 1:
A surgical instrument comprising:
an end effector (<NUM>) comprising an end effector base (<NUM>), an articulated jaw (<NUM>, <NUM>) rotationally coupled to the end effector base (<NUM>), and an opposing stationary jaw (<NUM>, <NUM>);
a cable actuation mechanism (<NUM>, <NUM>) comprising a first cable segment (<NUM>, <NUM>) and a second cable segment (<NUM>, <NUM>) drivingly coupled with the articulated jaw (<NUM>, <NUM>), the cable actuation mechanism (<NUM>, <NUM>) being operable to open the articulated jaw (<NUM>, <NUM>) relative to the opposing stationary jaw (<NUM>, <NUM>) via coordinated distal advancement of the first cable segment (<NUM>, <NUM>) and proximal retraction of the second cable segment (<NUM>, <NUM>), and operable to apply a grasping force to a tissue disposed between the articulated jaw (<NUM>, <NUM>) and the opposing stationary jaw (<NUM>, <NUM>) via coordinated proximal retraction of the first cable segment (<NUM>, <NUM>) and distal advancement of the second cable segment (<NUM>, <NUM>);
a first leadscrew actuation mechanism comprising a first drive shaft (<NUM>) and a first leadscrew (<NUM>) and operable to rotate the first drive shaft (<NUM>) to rotate the first leadscrew (<NUM>) to cause the articulated jaw (<NUM>, <NUM>) to apply a clamping force to the tissue; and
a second leadscrew actuation mechanism operable to rotate a leadscrew of the opposing stationary jaw (<NUM>, <NUM>).