Shaking system and method for maintaining grip

Abstract

This application discloses a jitter system and method for maintaining gripping force, comprising a computer-aided device. The computer-aided device includes an instrument having a first jaw and a second jaw configured to grip material; one or more actuators configured to actuate the first and second jaws to apply force to the gripped material; and a controller coupled to the one or more actuators. The controller is configured to determine that actuation of the one or more actuators should be jittered, and in response to the determination, jitter one or more control signals to the one or more actuators to cause a change in the force or torque applied by the one or more actuators. In some embodiments, the one or more control signals correspond to a force setpoint, torque setpoint, current setpoint, or position setpoint of the one or more actuators.

Description

[0001] Related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 899,085, filed September 11, 2019, entitled “System and Method of Dithering to Maintain Grasp Force,” which is incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to the operation of devices having repositionable arms and instruments, and more specifically to the operation of using shaking to maintain consistent grip force and prevent the generation of excessively strong grips on the instruments. Background Technology

[0004] More and more devices are being replaced by computer-aided electronic devices. This is especially true in industrial, recreational, educational, and other settings. As an example in healthcare, today's hospitals are filled with electronic equipment in operating rooms, interventional rooms, intensive care units, emergency rooms, and / or the like. For instance, glass and mercury thermometers are being replaced by electronic thermometers, intravenous drip lines now include electronic monitors and flow regulators, and traditional handheld surgical instruments and other medical devices are being replaced by computer-aided medical devices.

[0005] These computer-aided devices are useful for performing operations and / or procedures on materials (such as a patient's body tissue) located in a workspace. With many computer-aided devices, an operator (such as a surgeon in the medical example) can remotely control the device using one or more controls on an operator console. As the operator manipulates the various controls on the operator console, commands are forwarded from the operator console to the device in or near the workspace, to which one or more end effectors and / or instruments are attached. In this way, the operator is able to perform one or more procedures on materials or objects in the workspace using the end effectors and / or instruments. Depending on the desired procedure and / or the instruments used, the desired procedure can be performed partially or fully under the operator's control using remote and / or semi-automatic control, where the instruments can perform or change the order of operations based on one or more activation actions by the operator.

[0006] Instruments of different designs and / or configurations can be used to perform different tasks, procedures, and / or functions, allowing operators to perform any of a variety of procedures. Computer-aided instruments, whether manually, remotely, and / or semi-automatically actuated, can be used for a variety of operations and / or procedures and can have a variety of configurations. Many such instruments include an end effector mounted at the distal end of an axis that can be mounted to the distal end of a repositionable arm. In many operational scenarios, the axis can be configured to be inserted (e.g., a laparoscope, thoracoscope, and / or similar) through an opening (e.g., a body wall incision, a natural orifice, an access port, and / or the like) to reach a remote site within the workspace. In some instruments, an articulated wrist mechanism can be mounted to the distal end of the instrument axis to support the end effector, wherein the articulated wrist provides the ability to change the orientation of the end effector relative to the longitudinal axis of the axis. Examples of such instruments include, but are not limited to, cauterization, ablation, suturing, cutting, stapler, fusion, sealing, and / or combinations thereof. Therefore, instruments can include a variety of components and / or combinations of components to perform these procedures.

[0007] When access to a workspace is restricted, the size and / or strength of the instrument may be limited. As a medical example, when computer-assisted devices are used to perform minimally invasive surgical procedures, the instrument may have to pass through body orifices and / or be kept within the smallest possible body wall incision to minimize impact on the patient. In another example, when the workspace is contained (e.g., it is hazardous, climate-controlled, sterile, and / or similar), access to the workspace may be controlled through one or more reduced-size orifices. Consistent with the goal of accessing workspaces with limited access, end effectors are generally kept as small as possible while still allowing them to perform their intended tasks. One way to keep end effectors small is by actuating them using one or more inputs at the proximal end of the surgical instrument, which is typically located outside the patient's body. Various gears, levers, pulleys, cables, rods, belts, and / or the like can then be used to transmit the motion from one or more inputs along the axis of the instrument and actuate the end effector. For example, the drive mechanism at the proximal end of the instrument interacts with various actuators (e.g., motors, solenoids, servo systems, hydraulic systems, pneumatic systems, and / or the like provided on a repositionable arm of a computer-aided device located in or near the workspace). The actuators typically receive control signals via a main controller and provide input in the form of force and / or torque at the proximal end of the drive mechanism, which is ultimately transmitted through various gears, levers, pulleys, cables, rods, belts, and / or the like to actuate the end effector at the distal end of the drive mechanism.

[0008] Given the small size of the instruments and the use of transmission mechanisms, it may be desirable to operate the instruments with a smaller force and / or torque sufficient to perform the required procedures. This helps to reduce the size of the instruments, decrease the likelihood of applying more force and / or torque than necessary, and reduce wear and tear and / or similar occurrences on the instruments.

[0009] Therefore, improved methods and systems for instrument operation are needed while appropriately maintaining the amount of applied force and / or torque. Summary of the Invention

[0010] According to some embodiments, a computer-aided device includes an instrument having a first jaw and a second jaw configured to grasp material; one or more actuators configured to actuate the first and second jaws to apply force to the grasped material; and a controller coupled to the one or more actuators. The controller is configured to determine that actuation of the one or more actuators should be jittered, and in response to the determination, jitter one or more control signals to the one or more actuators to cause a change in the force or torque applied by the one or more actuators.

[0011] According to some embodiments, a method includes determining, via a controller of a computer-assisted device, that actuation of one or more actuators of the computer-assisted device should be jittered, said one or more actuators being usable to actuate a first jaw and a second jaw of the instrument to grasp material. The method further includes, in response to the determination, jittering one or more control signals from the controller to the one or more actuators to cause a change in the force or torque applied by the one or more actuators.

[0012] According to some embodiments, a non-transitory machine-readable medium comprising a plurality of machine-readable instructions, which, when executed by one or more processors associated with a computer-assisted medical device, are adapted to cause the one or more processors to perform any of the methods described herein. Attached Figure Description

[0013] Figure 1 This is a simplified diagram of a computer-aided system according to some embodiments.

[0014] Figure 2 This is a simplified diagram illustrating an apparatus according to some embodiments.

[0015] Figure 3 According to some embodiments Figure 2 A simplified perspective view of the distal end of the instrument.

[0016] Figure 4 This is a simplified diagram of a method of operating an instrument according to some embodiments.

[0017] In the diagram, elements with the same name have the same or similar functions. Detailed Implementation

[0018] This specification and accompanying drawings, which illustrate aspects, embodiments, implementation methods, or modules of the invention, should not be considered limiting—the claims define the protected invention. Various mechanical, compositional, structural, electrical, and operational changes may be made without departing from the spirit and scope of this specification and claims. In some cases, well-known circuits, structures, or techniques have not been shown or described in detail so as not to obscure the invention. Identical numbers in two or more figures represent the same or similar elements.

[0019] Specific details are set forth in this specification to describe some embodiments consistent with this disclosure. Numerous specific details are set forth to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that some embodiments may be practiced without some or all of these specific details. The specific embodiments disclosed herein are illustrative and not restrictive. Those skilled in the art will recognize other elements within the scope and spirit of this disclosure, although not specifically described herein. Furthermore, to avoid unnecessary repetition, one or more features shown and described in connection with one embodiment may be incorporated into other embodiments unless otherwise specifically described or if said one or more features would render the embodiment inoperable.

[0020] Furthermore, the terminology used in this specification is not intended to limit the invention. For example, spatially related terms (e.g., “below,” “under,” “lower,” “above,” “upper,” “near,” “far”, and / or similar terms) may be used to describe the relationship of one element or feature to another element or feature illustrated in the figures. In addition to the positions and orientations shown in the figures, these spatially related terms are intended to cover different positions (i.e., orientations) and orientations (i.e., rotational placements) of elements or their operation. For example, if the contents of one of the figures are flipped, an element described as “below” or “under” other elements or features would be “above” or “on” other elements or features. Thus, the exemplary term “below” can cover both above and below positions and orientations. Devices may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially related descriptions used herein are interpreted accordingly. Similarly, descriptions of movement along and around various axes include various specific element positions and orientations. Furthermore, unless the context otherwise indicates, the singular forms “a,” “an,” and “the” are also intended to include the plural forms. Furthermore, the terms "comprises," "comprising," "includes," and / or similar terms specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups. Components described as coupled may be electrically or mechanically directly coupled, or they may be indirectly coupled via one or more intermediate components.

[0021] Elements described in detail with reference to one embodiment, implementation, or module may be included, where feasible, in other embodiments, implementations, or modules that are not specifically shown or described therein. For example, if an element is described in detail with reference to one embodiment but not with reference to a second embodiment, that element may still be claimed to be included in the second embodiment. Therefore, to avoid unnecessary repetition in the following description, one or more elements shown and described in association with one embodiment, implementation, or application may be incorporated into other embodiments, implementations, or aspects unless otherwise specifically described, unless the one or more elements would render the embodiment or implementation inoperable, or unless two or more of the elements provide conflicting functionality.

[0022] In some cases, well-known methods, procedures, components, and circuits have not been described in detail to avoid unnecessarily obscuring aspects of the embodiments.

[0023] This disclosure describes various devices, components, and portions of computer-aided devices and components based on their states in three-dimensional space. As used herein, the term "position" refers to the orientation of an element or portion of an element in three-dimensional space (e.g., three translational degrees of freedom along Cartesian x-, y-, and z-coordinates). As used herein, the term "orientation" refers to the rotational placement of an element or portion of an element (three rotational degrees of freedom—e.g., roll, pitch, and yaw). As used herein, the term "shape" refers to a set position or orientation measured along the element. As used herein, and for devices with a repositionable arm, the term "proximal" refers to the direction of the kinematic chain along the base of the computer-aided device toward the base of the computer-aided device, and "distal" refers to the direction along the kinematic chain away from the base.

[0024] The present disclosure describes aspects of computer-aided systems and apparatus, which may include remotely controlled, remotely controlled, automated, semi-automated, robotic, and / or similar systems and apparatus. Furthermore, aspects of the present disclosure are based on the use of surgical systems (e.g., Da...). This description refers to an implementation of a surgical system. However, those skilled in the art will understand that the inventive aspects disclosed herein can be embodied and practiced in various ways, including robotic and (if applicable) non-robotic embodiments and implementations. The implementations of surgical systems are merely exemplary and should not be construed as limiting the scope of the inventive aspects disclosed herein. For example, the techniques described with reference to surgical instruments and methods can be used in other contexts. Therefore, the instruments, systems, and methods described herein can be used with respect to humans, animals, parts of human or animal anatomy, industrial systems, general-purpose robots, or remote-controlled systems. As further examples, the instruments, systems, and methods described herein can be used for non-medical purposes, including industrial applications, general-purpose robotic applications, sensing or manipulating non-tissue artifacts, cosmetic enhancements, imaging of human or animal anatomy, collecting data from human or animal anatomy, establishing or dismantling systems, training medical or non-medical personnel and / or the like. Additional example applications include procedures for removing tissue from human or animal anatomy (without returning the human or animal anatomy) and procedures for human or animal cadavers. Furthermore, these techniques can also be used in medical treatment or diagnostic procedures, with or without surgical aspects.

[0025] Figure 1 This is a simplified diagram of a computer-aided system 100 according to some embodiments. For example... Figure 1As shown, the computer-aided system 100 includes a computer-aided device 110 having one or more movable or repositionable arms 120. Each of the one or more repositionable arms 120 can support one or more instruments 130. In some examples, the computer-aided device 110 may be consistent with a computer-aided surgical device. The one or more repositionable arms 120 may all provide support for the instruments 130 (e.g., surgical instruments, imaging devices, and / or the like). In some examples, the instruments 130 may include end effectors capable of, but not limited to, performing, clamping, retracting, cauterizing, ablating, suturing, cutting, stapled, fused, sealing, and / or combinations thereof.

[0026] The computer-aided device 110 may be further coupled to an operator workstation (not shown), which may include one or more master controls for operating the computer-aided device 110, one or more repositionable arms 120, and / or instruments 130. In some examples, the one or more master controls may include master actuators, levers, pedals, switches, keys, knobs, triggers, and / or the like. In some embodiments, the computer-aided device 110 and the operator workstation may correspond to the Da commercialized by Intuitive Surgical, Inc. of Sunnyvale, California. Surgical system. In some embodiments, computer-assisted surgical devices with other configurations, fewer or more repositionable arms and / or similar features may be used with computer-assisted system 100.

[0027] Computer-aided device 110 is coupled to control unit 140 via an interface. This interface may include one or more cables, optical fibers, connectors, and / or buses, and may also include one or more networks with one or more network switching and / or routing devices. Control unit 140 includes processor 150 coupled to memory 160. Operation of control unit 140 is controlled by processor 150. And although control unit 140 is shown as having only one processor 150, it is understood that processor 150 may represent one or more central processing units, multi-core processors, microprocessors, microcontrollers, digital signal processors, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), tensor processing units (TPUs), and / or the like in control unit 140. Control unit 140 may be implemented as a separate subsystem and / or board added to a computing device, or implemented as a virtual machine. In some embodiments, control unit 140 may be included as part of and / or operate separately from the operator's workstation, but coordinated with the operator's workstation.

[0028] Memory 160 may be used to store software executed by control unit 140 and / or one or more data structures used during operation of control unit 140. Memory 160 may include one or more types of machine-readable media. Some common forms of machine-readable media may include floppy disks, hard disks, magnetic tapes, any other magnetic media, CD-ROMs, any other optical media, punched cards, paper tapes, any other physical media with a perforated pattern, RAM, PROMs, EPROMs, FLASH-EPROMs, any other memory chips or cassette memories, and / or any other media suitable for reading by a processor or computer.

[0029] like Figure 1 As shown, memory 160 includes a control module 170 that can be used to support autonomous, semi-autonomous, and / or remote control of computer-assisted device 110. Control module 170 may include one or more application programming interfaces (APIs) for: receiving position, motion, force, torque, and / or other sensor information from computer-assisted device 110, repositionable arm 120, and / or instrument 130; exchanging position, motion, force, torque, and / or collision avoidance information with other control units regarding other devices; and / or planning and / or assisting in planning the motion of computer-assisted device 110, repositionable arm 120, and / or instrument 130. In some examples, control module 170 may further support autonomous, semi-autonomous, and / or remote control of instrument 130 during procedures (e.g., surgical procedures). And although control module 170 is depicted as a software application, control module 170 may be implemented using hardware, software, and / or a combination of hardware and software.

[0030] In some medical embodiments, the computer-assisted system 100 may be found in an operating room and / or interventional suite. And although the computer-assisted system 100 comprises only one computer-assisted device 110 with two repositionable arms 120 and corresponding instruments 130, those skilled in the art will understand that the computer-assisted system 100 may include any number of computer-assisted devices with repositionable arms and / or instruments that are similar in design to and / or different from the computer-assisted device 110. In some examples, each of the computer-assisted devices may include fewer or more repositionable arms and / or instruments.

[0031] Figure 2 This is a simplified diagram illustrating an apparatus 200 according to some embodiments. In some embodiments, the apparatus 200 may be... Figure 1 Any instrument consistent with 130. Figure 2The “proximal” and “distal” directions described herein help to describe the relative orientation and orientation of the components of instrument 200. Distal generally refers to elements further away from the base of the computer-aided device (e.g., computer-aided device 110) along the kinetic chain, and / or elements closest to the intended operational workspace of instrument 200. Proximal generally refers to elements closer to the base of the computer-aided device and / or a repositionable arm of the computer-aided device along the kinetic chain.

[0032] like Figure 2 As shown, the device 200 includes an elongated shaft 210 for coupling an end effector 220 located at the distal end of the shaft 210 to a position where the device 200 is mounted to a repositionable arm and / or computer-aided device, located proximally on the shaft 210. Depending on the specific procedure in which the device 200 is used, the shaft 210 can be inserted through an opening (e.g., a body wall incision, a natural orifice, a workspace port, and / or the like) to position the end effector 220 close to a remote working site located within a workspace (e.g., the patient's internal anatomy in a medical example). Figure 2 As further shown, the end effector 220 is typically consistent with a dual-clamp type end effector. In some embodiments, the dual-clamp type end effector may also include a cutting and / or welding or sealing mechanism, as described below. Figure 3 A more detailed description is provided. However, those skilled in the art will understand that different instruments 200 with different end effectors 220 are possible and can be consistent with embodiments of the instrument 200 described elsewhere herein.

[0033] Instruments (e.g., instrument 200 with end effector 220) typically rely on multiple degrees of freedom (DOF) during their operation. Depending on the configuration of instrument 200 and the repositionable arm and / or computer-aided device to which it is mounted, various degrees of freedom that can be used for positioning, orienting, and / or manipulating the end effector 220 are possible. In some examples, axis 210 can insert distally and / or retract proximally to provide an insertion DOF that can be used to control how deep the end effector 220 is placed within the workspace. In some examples, axis 210 is capable of rotating about its longitudinal axis to provide a roll degree of freedom that can be used to rotate the end effector 220. In some examples, additional flexibility in the position and / or orientation of the end effector 220 can be provided by an optional articulated wrist 230 for coupling the end effector 220 to the distal end of axis 210. In some examples, the articular wrist 230 may include one or more rotary joints (e.g., one or more roll, pitch, or yaw joints that may provide one or more "roll," "pitch," and "yaw" DOFs, respectively), which can be used to control the orientation of the end effector 220 relative to the longitudinal axis of shaft 210. In some examples, the one or more rotary joints may include pitch and yaw joints; roll, pitch, and yaw joints; roll, pitch, and roll joints; and / or the like. In some examples, the end effector 220 may also include a clamping DOF for controlling the opening and closing of the jaws of the end effector 220 and / or an activation DOF for controlling the extension, retraction, and / or operation of the cutting mechanism.

[0034] The instrument 200 also includes a drive system 240 located at the proximal end of shaft 210. The drive system 240 includes one or more components for introducing force and / or torque into the instrument 200 for manipulating various degrees of freedom (DOF) supported by the instrument 200. In some examples, the drive system 240 may include a drive system based on a control unit (e.g., Figure 1 The control unit 140 receives signals to operate one or more actuators, such as motors, solenoids, servo systems, hydraulic devices, pneumatic devices, and / or the like. In some examples, the signals may include one or more current, voltage, pulse-width modulated waveforms, and / or the like. In some examples, the drive system 240 may include one or more shafts, gears, pulleys, rods, belts, and / or the like, which may be coupled to a corresponding actuator as part of a repositionable arm (e.g., any repositionable arm 120) on which the instrument 200 is mounted. In some examples, the one or more drive inputs (e.g., shafts, gears, pulleys, rods, belts, and / or the like) may be used to receive forces and / or torques from the actuators and apply those forces and / or torques to adjust various degrees of freedom (DOF) of the instrument 200.

[0035] In some embodiments, forces and / or torques generated and / or received by the drive system 240 can be transferred from the drive system 240 and along the shaft 210 to various joints and / or elements of the instrument 200 located distal to the drive system 240 using one or more drive mechanisms 250. In some examples, the one or more drive mechanisms 250 may include one or more gears, levers, pulleys, cables, rods, belts, and / or the like. In some examples, the shaft 210 is hollow, and the one or more drive mechanisms 250 extend from the drive system 240 along the interior of the shaft 210 to the corresponding DOF in the end effector 220 and / or articulated wrist 230. In some examples, each of the one or more drive mechanisms 250 may be a cable disposed within a hollow sheath or lumen in a Bowden cable-like configuration. In some examples, the interior of the cable and / or lumen may be coated with a low-friction coating, such as polytetrafluoroethylene (PTFE) and / or the like. In some examples, as the proximal end of each of the cables is pulled and / or pushed within the drive system 240 (e.g., by winding and / or unwinding the cable around a winch or shaft), the distal end of the cable moves accordingly and applies appropriate force and / or torque to adjust one of the DOFs of the end effector 220, the articulated wrist 230, and / or the device 200.

[0036] Figure 3 This is a simplified perspective view of the distal end of the device 200 according to some embodiments. (e.g.) Figure 3 As shown, the distal end of the instrument 200 is drawn to illustrate additional details of the end effector 220, the articulated wrist 230, and one or more drive mechanisms 250. More specifically, the end effector 220 includes opposing jaws 310 shown in an open position. The jaws 310 are configured to move between an open position and a closed position, such that the end effector 220 can be used during a procedure to grasp and release material (e.g., tissue in a medical example) and / or other objects at a remote work site. In some examples, the jaws 310 may operate together as a single unit, with both jaws 310 opening and / or closing simultaneously. In some examples, the jaws 310 may open and / or close independently, such that, for example, one jaw 310 can remain stable while the other jaw 310 can open and / or close.

[0037] Figure 3The clamping surfaces on the inner side of each of the jaws 310 include corresponding grooves 320, which can act as guides for the optional cutting blade 330, although the grooves 320 may be omitted from one or more of the jaws 310. Each of the grooves 320 assists in the alignment and / or positioning of the cutting blade 330 during cutting operations as the cutting blade 330 extends toward the distal end of the end effector 220 and / or retracts toward the proximal end of the end effector 220. The withdrawal and / or retraction of the cutting blade 330 is accomplished using a drive assembly 340 to which the cutting blade 330 is attached. In some examples, the drive assembly 340 pushes the cutting blade 330 to extend it and pulls it to retract it.

[0038] In some embodiments, the clamping surfaces on the inner sides of each of the jaws 310 may also include one or more optional electrodes 350. In some examples, the electrodes 350 may be used to deliver electrosurgical energy to fuse and / or cut material held between the jaws 310 (e.g., tissue in a medical example). In some examples, the electrodes 360 may provide electrocautery, fusion, and / or sealing features to the end effector 220 so that the same instrument 200 can be used to cut and / or fuse / seal material.

[0039] In some embodiments, the operation of the joints of the jaws 310, the cutting blade 330, and / or the articulated wrist 230 can be accomplished using corresponding drive mechanisms among the one or more drive mechanisms 250. In some examples, when the jaws 310 operate independently, the distal ends of two of the one or more drive mechanisms 250 (one for each jaw 310) can be coupled to the corresponding jaw 310, such that when the corresponding one or more drive mechanisms 250 apply a pulling and / or pushing force (e.g., using a cable, lead screw, and / or the like), the corresponding jaw 310 can be opened and / or closed. In some examples, when the jaws 310 operate together, two jaws 310 can be coupled to the distal ends of the same one or more drive mechanisms 250. In some examples, the drive assembly 340 can be coupled to the distal ends of the corresponding drive mechanism 250, such that forces and / or torques applied to the corresponding one or more of the one or more drive mechanisms 250 can be transmitted to the drive assembly 340 for pushing and / or pulling movements. In some examples, one or more additional drive mechanisms 250 may be used to operate the roll, pitch, and / or yaw (DOF) of the articular wrist 230.

[0040] According to some embodiments, the amount of gripping force applied by the jaws 310 to the gripped material may be affected by one or more of the following factors: the closing speed of the jaws 310, the amount of joint movement in the articulated wrist 230, and / or other factors. In some examples, a larger amount of joint movement in the articulated wrist 230 may cause an increase in the amount of gripping force applied by the jaws 310 to the gripped material (e.g., tissue in a medical example). In some examples, causing the wrist to articulate while gripping the tissue will cause a change in the amount of force applied to the tissue. In some examples, the amount of gripping force may also be affected by friction (e.g., static friction or adhesion) in the device 200 (e.g., in the actuator, in the drive system 240, between the actuator and / or drive system 240 and the one or more drive mechanisms 250, due to the joint movement of the articulated wrist 230, between the one or more drive mechanisms 250 and the end effector 220, and / or the like) and / or between the jaws 310 and / or the one or more electrodes 350 and the gripped material. In some examples, this ambiguity in gripping force is undesirable for usability, manufacturing, and control purposes because it creates uncertainty about whether the material is being gripped correctly (e.g., before performing other actions such as cutting, sewing, energy delivery, and / or similar actions), which, if not properly restrained, could lead to excessive wear and tear and / or similar conditions of the instrument.

[0041] According to some embodiments, several approaches can be used to address these problems. In some examples, reducing friction between the jaws 310 and / or the one or more electrodes 350 and the gripped material can help reduce the effects of friction. In some examples, rapidly increasing the gripping force to awaken the clamping mechanism and “reset” the friction (e.g., converting static friction in the one or more drive mechanisms 250 to kinetic friction, and / or similar approaches) can be helpful. In some examples, preventing changes in the joint movement of the articulated wrist 230 when sealing and cutting the gripped material using the one or more electrodes 350 can limit the effects of the joint movement of the articulated wrist 230. In some examples, adjusting the amount of force and / or torque applied by the one or more actuators for the jaws 310 based on the amount of joint movement of the articulated wrist 230 can also limit the effects of the joint movement of the articulated wrist 230.

[0042] In some examples, reducing surface friction of the jaws 310 and / or one or more electrodes 350 provides only limited improvement because surface friction cannot be reduced below a reasonable threshold required to maintain proper gripping of the grasped tissue by the jaws 310. In some examples, preventing changes in joint movement of the wrist 230 negatively impacts usability. In some examples, approaches that increase gripping force by arousal and / or solely based on the amount of joint movement in the wrist 230 may result in gripping forces exceeding what is necessary, potentially leading to undesirable wear and tear (and loss of life) of the grasped material, the instrument 200, and / or similar conditions due to excessive gripping force.

[0043] According to some embodiments, dithering (e.g., rapid modulation) can resolve friction problems (one or more actuators) by adjusting the amount of force and / or torque applied by one or more actuators used to control the amount of gripping force between the jaws 310 and / or the one or more electrodes 350 and the gripped material, without causing an undesirable increase in gripping force. In some examples, dithering helps to convert static friction in the instrument 200 (e.g., in the one or more drive mechanisms) and / or between the jaws 310 and / or the one or more electrodes 350 and the gripped material into kinetic friction that allows for the application of a suitable gripping force on the gripped material, while avoiding high spikes in force and / or torque applied by the actuators that could cause undesirable wear and tearing of the instrument 200. In some examples, dithering causes movement of the instrument 200 (e.g., in the one or more drive mechanisms) that results in a change in the amount of force applied by the jaws 310 to grip the material.

[0044] Figure 4 This is a simplified diagram of a method 400 for operating an instrument according to some embodiments. One or more of the processes 410-440 of method 400 may be implemented, at least in part, in the form of executable code stored on a non-transient, tangible, machine-readable medium, which, when run by one or more processors (e.g., processor 150 in control unit 140), can cause one or more processors to perform one or more of processes 410-440. In some embodiments, method 400 may be performed by a module (e.g., control module 170). In some embodiments, method 400 may be used to operate an instrument such that an appropriate gripping force can be maintained on a grasped material (e.g., tissue in a medical example) to perform a procedure, while avoiding excessive gripping force due to joint movement of the wrist, friction within the instrument or between the instrument and the grasped material, and / or similar conditions. In some examples, method 400 may be used to perform a procedure using instrument 200.

[0045] According to some embodiments, method 400 may include Figure 4Additional processes not shown. In some embodiments, processes 410-440 of method 400 may be coupled with... Figure 4 The arrangement implies a different order of execution. In some examples, processes 420 and / or 430 may be executed concurrently with process 440.

[0046] At process 410, the instrument command is received. In some examples, the instrument command can be received from the operator, for example, by using an operator console. In some examples, the operator console can be about... Figure 1 The described operator console. In some examples, instrument commands can be received via an interface. In some examples, instrument commands can be received via one or more API calls to a control module (e.g., control module 170). In some examples, instrument commands may be commands to apply cutting and / or sealing energy (e.g., which may be applied by the one or more electrodes 350) to the grasped material. In some examples, instrument commands may be commands to change the joint movement of an articulated wrist (e.g., articulated wrist 230).

[0047] At process 420, it is determined whether jitter should be performed. In some examples, this determination may depend on one or more of the following: the type of instrument command received during process 410, the current configuration of the instrument (e.g., the amount of joint movement at the wrist, the spacing between the instrument's jaws (e.g., jaws 310), an increase and / or decrease in the amount of force applied by the jaws, and / or similar factors). In some examples, jitter should be performed when the instrument command is a command to apply cutting and / or sealing energy. In some examples, when the instrument command is to change the joint movement of the wrist, jitter should be performed if the instrument command results in one or more joint movement conditions. In some examples, the one or more joint movement conditions include whether the wrist is articulating while gripping material between the jaws 310. In some examples, the one or more joint motion conditions include: whether the amount of joint motion at the wrist exceeds a configurable angle threshold (e.g., 15-60 degrees), whether the change in joint motion at the wrist exceeds a configurable angle change threshold (e.g., 15-60 degrees), whether the rate of change in joint motion at the wrist exceeds a configurable angular velocity threshold (e.g., 10 to 60 degrees / second), and / or similar conditions. When jitter is to be performed, it is performed using procedure 430. In some examples, when the instrument command is to change the amount of force applied by the jaws, jitter should be performed when the instrument command results in one or more gripping conditions being present. In some examples, the one or more gripping conditions include: whether the amount of force applied by the jaws to the gripped material exceeds a configurable force threshold (e.g., 40-50 Newtons), whether the amount of force applied by the jaws to the gripped material is below a configurable force threshold (e.g., 5 to 10 Newtons), whether the change in the amount of force applied by the jaws exceeds a configurable force change threshold (e.g., 8 to 18 Newtons), and / or similar conditions. In some examples, the amount of force applied by the jaws can be determined using one or more sensors (e.g., one or more pressure sensors, strain gauges, and / or the like) located on the jaws or drivetrain 250. When jitter is to be performed, it is done using process 430. When jitter is not to be performed, the instrument command is executed without jitter using process 440.

[0048] At process 430, one or more actuator control signals are jittered. According to some embodiments, the one or more actuator control signals are jittered based on four configurable parameters: the jittered signal shape, the jitter amplitude, the jitter frequency, and the jitter duration. In some examples, the jittered signal shape can be a sine wave, square wave, triangle wave, sawtooth wave, and / or similar shape. In some examples, jitter can be a combination of multiple signal shapes (e.g., components of two or more frequencies, a square wave with sinusoidal ripples, and / or similar shapes).

[0049] In some examples, the jitter amplitude can be a configurable percentage (e.g., 10-30%) of the setpoint of the corresponding actuator control signal. In some examples, the setpoint can correspond to the actuator's position setpoint (e.g., the position of the actuator when it is driving the jaws of the end effector), force and / or torque setpoint (e.g., the amount of force or torque that can be applied by the corresponding actuator to actuate the jaws), current setpoint for supplying current to the corresponding actuator (e.g., which is typically related to the applied force and / or torque), a combination of some of the above, and / or similar values. In some examples, the jitter amplitude can be a configurable percentage of the corresponding actuator's setpoint limits (e.g., position, force, torque, current limits, and / or similar values). In some examples, the jitter amount can be limited so as not to exceed the corresponding actuator's setpoint limits and / or to maintain a configurable minimum gripping force. In some examples, although jitter can be configured around a setpoint (e.g., torque), limitations on position and / or speed can be additionally enforced, which may cause clipping of the jitter signal in some use cases. In some examples, limitations on the amount of jitter can lead to asymmetrical jitter with respect to the setpoint of the corresponding actuator. In some examples, the amplitude of the jitter can be inversely proportional to the duration of the jitter.

[0050] In some examples, the frequency of the jitter can be at a configurable frequency (e.g., 5-10 Hz). In some examples, the frequency of the jitter can be equal to or slightly higher than (e.g., 1-5 Hz higher) the instrument's natural frequency due to the respective actuators, drive units (e.g., drive system 240), the one or more drive mechanisms (e.g., the one or more drive mechanisms 250), the joint motion effects of the wrist, the contributions of the grippers and / or the material being gripped. In some examples, the natural frequency can be determined empirically, for example, during instrument calibration. In some examples, the frequency can be additionally adjusted as a function of the jitter duration and / or the number of jitter cycles, such that the frequency increases or decreases with each cycle completed and / or over time.

[0051] In some examples, the duration of jitter may depend on the type of instrument command received during process 410. In some examples, when the instrument command is to apply cutting and / or sealing energy, jitter may be applied for a first configurable time period (e.g., 0.25–1.0 seconds) prior to energy application, thus delaying the application of cutting and / or sealing energy. In some examples, jitter is applied throughout the entire application of cutting and / or sealing energy. In some examples, jitter continues for a second configurable time period (e.g., 0.25–1.0 seconds) after the application of cutting and / or sealing energy has ended. In some examples, when the instrument is commanded to change the joint motion of the wrist, jitter may begin upon detection of a joint motion condition that triggers jitter (e.g., joint motion magnitude, joint motion change, and / or angular velocity) and continue until further joint motion ceases. In some examples, joint motion may be considered to have stopped when no more joint motion commands for the wrist are received, the angular velocity of the joint motion is below a configurable threshold, the joint motion condition no longer exists, and / or similar conditions. In some examples, joint movement can be considered to have stopped when no changes in joint movement commands are received for a configurable time period (e.g., 0.5-1.0 seconds), the angular velocity of the joint movement is lower than a configurable threshold, the joint movement condition no longer exists, and / or similar conditions.

[0052] In some examples, when the instrument is commanded to change the amount of force applied by the jaws, jitter may begin and continue upon detection of a gripping condition that triggers jitter (e.g., the amount of force applied by the jaws or a change in the amount of force applied by the jaws) until further changes in the amount of force applied by the jaws cease. In some examples, the change in the amount of force applied by the jaws may be considered to have stopped when no further commands for force changes applied to the jaws are received, the amount of change in force applied by the jaws is below a configurable threshold, the gripping condition no longer exists, and / or similar conditions are met. In some examples, the change in the amount of force applied by the jaws may be considered to have stopped when no further commands for force changes applied to the jaws are received for a configurable time period (e.g., 0.5–1.0 seconds), the amount of change in force applied by the jaws is below a configurable threshold, the gripping condition no longer exists, and / or similar conditions are met.

[0053] In some examples, one or more programmable timers can be used to monitor and / or track time periods. In some examples, the duration of jitter can be inversely proportional to the amplitude of jitter.

[0054] According to some embodiments, jitter can be implemented in the control signals of one or more actuators by applying jitter to a setpoint of the respective actuator. In some examples, jitter can be applied to the setpoint by superimposing jitter onto it. In some examples, the nominal value of the setpoint can be determined by a device command received during process 410. In some examples, the setpoint can be a setpoint used by the controller of the respective actuator to control the force and / or torque applied by the respective actuator. In some examples, the setpoint can be a force setpoint, torque setpoint, current setpoint, and / or similar setpoint. In some examples, the setpoint can be a setpoint used by the controller of the respective actuator to control the position of the respective actuator, wherein the respective actuator controls the position of one or more jaws, the spacing between the jaws, and / or similar characteristics.

[0055] At process 440, the instrument command is executed. The instrument command is executed with or without jitter, depending on whether process 430 is executed. In some examples, the instrument command is executed by setting one or more setpoints (e.g., the nominal setpoints described with respect to process 430) for a controller used to control the instrument and / or end effector. In some examples, the instrument command may result in one or more of the following: changes in joint movement at the wrist joint, changes in jaw spacing, changes in the force applied by the jaws to the grasped material, application of cutting and / or sealing energy to the material by one or more electrodes, and / or similar characteristics. In some examples, the instrument command may be executed by sending one or more actuator signals to the corresponding actuator, sending one or more signals to the controller for energy delivery, and / or similar actions.

[0056] Once an instrument command is executed, method 400 can be repeated for another instrument command by returning to process 410.

[0057] As stated above and further emphasized here, Figure 4These are merely examples and should not be construed as unduly limiting the scope of the claims. Those skilled in the art will recognize many changes, substitutions, and modifications. According to some embodiments, various properties of method 400 (e.g., thresholds, percentages, time periods, and / or the like) can be configured based on one or more factors and / or combinations of one or more factors. In some examples, one or more factors include the type of instrument, instrument calibration, instrument lifespan (e.g., number of previous uses), the procedure being performed, operator preference, the type of material being grasped, the spacing between the jaws (e.g., angle and / or distance), the rate of change of the jaw spacing, the amount of joint motion at the wrist joint, the angular velocity of the change of joint motion at the wrist joint, and / or the like. In some examples, the amount of jitter (e.g., amplitude and / or duration) may be higher for instruments with fewer uses. In some examples, the amount of jitter may be higher for larger jaw spacing, larger rates of change of jaw spacing, higher amount of joint motion at the wrist joint, higher angular velocity of the change of joint motion at the wrist joint, the amount of force exerted by the jaws on the material being grasped, and / or the like. In some examples, the amount of force exerted by the jaws on the gripped material can be determined using one or more sensors (e.g., one or more pressure sensors, strain gauges, and / or the like) located on the jaws and / or drive mechanism.

[0058] Some examples of control units (e.g., control unit 140) may include non-transitory, tangible, machine-readable media containing machine-readable instructions that, when run by one or more processors (e.g., processor 150), can cause one or more processors to perform the process of method 400. Some common forms of machine-readable media that may include the process of method 400 are, for example, floppy disks, hard disks, magnetic tapes, any other magnetic media, CD-ROMs, any other optical media, punched cards, paper tapes, any other physical media with a perforated pattern, RAM, PROMs, EPROMs, FLASH-EPROMs, any other memory chips or cassette memories, and / or any other media suitable for reading by a processor or computer.

[0059] Although illustrative embodiments have been shown and described, a wide range of modifications, alterations, and substitutions are contemplated in the foregoing disclosure, and in some cases, some features of the embodiments may be employed without corresponding use of others. Many changes, substitutions, and modifications will be recognized by those skilled in the art. Therefore, the scope of the invention should be limited only by the following claims, and it is appropriate to interpret the claims broadly in a manner consistent with the scope of the embodiments disclosed herein.

Claims

1. A computer-assisted device comprising: an instrument having a first jaw and a second jaw configured to grasp a material; one or more actuators configured to actuate the first and second jaws to apply a force to the grasped material; and a controller coupled to the one or more actuators; wherein the controller is configured to: determine that actuation of the one or more actuators should be dithered; and in response to the determination, dither one or more control signals to the one or more actuators so as to cause a change in the force or torque applied by the one or more actuators; wherein the amplitude of the dithering is: a percentage of a set value of a respective one of the one or more control signals; or a percentage of a limit on a set value of a respective one of the one or more control signals.

2. The computer-assisted device of claim 1, wherein the material is body tissue.

3. The computer-assisted device of claim 1, wherein the one or more control signals correspond to a force set value of the one or more actuators, a torque set value of the one or more actuators, a current set value of the one or more actuators, or a position set value of the one or more actuators.

4. The computer-assisted device of claim 1, wherein the controller is further configured to determine the force applied to the grasped material using one or more sensors on the first and second jaws or one or more drive mechanisms coupling the one or more actuators to the first and second jaws.

5. The computer-assisted device of claim 1, wherein the dithering is superimposed on the one or more control signals.

6. The computer-assisted device of claim 1, wherein the dithering is applied as a sine wave, a square wave, a triangle wave, a sawtooth wave, or a combination of two or more waves.

7. The computer-assisted device of claim 1, wherein the amplitude of the dithering is limited so as not to violate one or more set value limits of a respective one of the one or more control signals.

8. The computer-assisted device of claim 1, wherein the dithering is asymmetric with respect to a set value of a respective one of the one or more control signals.

9. The computer-assisted device of claim 1, wherein the frequency of the dithering is between 5 and 10 Hertz, inclusive.

10. The computer-assisted device of claim 1, wherein the frequency of the dithering is equal to or higher than a natural frequency of the instrument.

11. The computer-assisted device of claim 1, wherein the controller is further configured to determine one or more properties of the dithering based on one or more of: a type of the instrument; a calibration of the instrument; some previous use of the instrument; a procedure being performed with the instrument; an operator preference; a type of the material; a spacing between the first and second jaws; a change in the spacing between the first and second jaws; an articulation of an articulating wrist of the instrument; an angular velocity of the articulation; or ​ ​ An amount of the force applied to grasp the material.

12. The computer-assisted device of claim 1, wherein the dithering causes movement in one or more drive mechanisms that couple the one or more actuators to the first jaw and second jaw.

13. The computer-assisted device of claim 1, wherein to determine that the actuation of the one or more actuators should be dithered, the controller is configured to determine whether: a command to apply cutting energy, sealing energy, or both cutting and sealing energy is received.

14. The computer-assisted device of any of claims 1-13, wherein the controller is further configured to begin dithering of the one or more control signals for a first time period prior to application of cutting energy, sealing energy, or both cutting and sealing energy using one or more electrodes on the first jaw, the second jaw, or both the first jaw and the second jaw.

15. The computer-assisted device of claim 14, wherein the controller is further configured to continue the dithering of the one or more control signals concurrently with the application of the cutting energy, the sealing energy, or both the cutting and sealing energy.

16. The computer-assisted device of claim 15, wherein the controller is further configured to continue the dithering of the one or more control signals for a second time period after the cutting energy, the sealing energy, or both the cutting and sealing energy is no longer being applied.

17. The computer-assisted device of any of claims 1-13, wherein to determine that the actuation of the one or more actuators should be dithered, the controller is configured to determine whether one or more articulation conditions exist, the one or more articulation conditions comprising: an articulation of an articulating wrist of the instrument is above an articulation threshold; a change in the articulation of the articulating wrist is above an articulation change threshold; or a rate of change of the articulation of the articulating wrist is above an angular velocity threshold.

18. The computer-assisted device of claim 17, wherein the controller is further configured to dither the one or more control signals while the one or more articulation conditions exist.

19. The computer-assisted device of claim 18, wherein the controller is further configured to continue dithering the one or more control signals for a period of time after the one or more articulation conditions no longer exist.

20. The computer-assisted device of any of claims 1-13, wherein to determine that the actuation of the one or more actuators should be dithered, the controller is configured to determine whether one or more grasping conditions exist, the one or more grasping conditions comprising: the force applied by the first jaw and second jaw to grasp the material is below a first force threshold; the force applied by the first jaw and second jaw to grasp the material is above a second force threshold; or a change in the force applied by the first jaw and second jaw to grasp the material is above a force change threshold.

21. The computer-assisted device of claim 20, wherein the controller is further configured to dither the one or more control signals while the one or more grasping conditions exist.

22. The computer-assisted device of claim 21, wherein the controller is further configured to continue dithering the one or more control signals for a period of time after the one or more grasping conditions no longer exist.

23. The computer-assisted device of any of claims 1-13, wherein the controller is further configured to: receive a command to control the instrument; and in response to receiving the command, determine whether the actuation of the one or more actuators should be dithered.

24. The computer-assisted device of claim 23, wherein the command is a command to change articulation of an articulating wrist of the instrument, a command to apply cutting energy, sealing energy, or both cutting and sealing energy to the grasped material using one or more electrodes on the first jaw, the second jaw, or both the first and second jaws, or a command to change the force applied to grasp the material.

25. The computer-assisted device of claim 23, wherein the controller is further configured to execute the command using the instrument.

26. A non-transitory machine-readable medium comprising a plurality of machine- readable instructions that, when executed by one or more processors associated with a computer-assisted device, are adapted to cause the one or more processors to perform a method comprising: determining that actuation of one or more actuators of the computer-assisted device, the one or more actuators being usable to actuate first and second jaws of an instrument to grasp material, should be dithered; and in response to the determination, dither one or more control signals to the one or more actuators so as to cause a change in force or torque applied by the one or more actuators; wherein the dithering has a magnitude that is: a percentage of a set value of a respective one of the one or more control signals; or a percentage of a limit on a set value of a respective one of the one or more control signals.

27. The non-transitory machine-readable medium of claim 26, wherein the material is body tissue.

28. The non-transitory machine-readable medium of claim 26, wherein the one or more control signals correspond to a force set value of the one or more actuators, a torque set value of the one or more actuators, a current set value of the one or more actuators, or a position set value of the one or more actuators.

29. The non-transitory machine-readable medium of claim 26, wherein the method further comprises determining the force applied to the grasped material using one or more sensors on the first and second jaws or one or more drive mechanisms that couple the one or more actuators to the first and second jaws.

30. The non-transitory machine-readable medium of claim 26, wherein the dithering is superimposed on the one or more control signals.

31. The non-transitory machine-readable medium of claim 26, wherein the dithering is applied as a sine wave, a square wave, a triangle wave, a sawtooth wave, or a combination of two or more waves.

32. The non-transitory machine readable medium of claim 26, wherein an amplitude of the dithering is limited to not violate one or more set value limits of a respective one of the one or more control signals.

33. The non-transitory machine readable medium of claim 26, wherein the dithering is asymmetric with respect to set values of a respective one of the one or more control signals.

34. The non-transitory machine readable medium of claim 26, wherein a frequency of the dithering is between 5 and 10 Hertz, inclusive.

35. The non-transitory machine readable medium of claim 26, wherein the frequency of the dithering is equal to or higher than a natural frequency of the instrument.

36. The non-transitory machine readable medium of claim 26, wherein the method further comprises determining one or more properties of the dithering based on one or more of: a type of the instrument; a calibration of the instrument; some previous use of the instrument; a procedure being performed with the instrument; an operator preference; a type of the material; a spacing between the first jaw and the second jaw; a change in the spacing between the first jaw and the second jaw; an articulation of an articulating wrist of the instrument; an angular velocity of the articulation; or an amount of the force applied to grasp the material.

37. The non-transitory machine readable medium of claim 26, wherein the dithering causes movement in one or more drive mechanisms that couple the one or more actuators to the first jaw and the second jaw.

38. The non-transitory machine readable medium of claim 26, wherein determining that the actuation of the one or more actuators should be dithered comprises determining whether: a command to apply cutting energy, sealing energy, or both cutting and sealing energy is received.

39. The non-transitory machine readable medium of any of claims 26-38, wherein the method further comprises starting the dithering of the one or more control signals for a first time period prior to applying cutting energy, sealing energy, or both cutting and sealing energy using one or more electrodes on the first jaw, the second jaw, or both the first jaw and the second jaw.

40. The non-transitory machine readable medium of claim 39, wherein the method further comprises continuing the dithering of the one or more control signals while the cutting energy, the sealing energy, or both cutting and sealing energy is being applied.

41. The non-transitory machine readable medium of claim 40, wherein the method further comprises continuing the dithering of the one or more control signals for a second time period after the cutting energy, the sealing energy, or both cutting and sealing energy is no longer being applied.

42. The non-transitory machine readable medium of any of claims 26-38, wherein determining that the actuation of the one or more actuators should be dithered comprises determining whether one or more articulation conditions exist, the one or more articulation conditions comprising: an articulation angle of the instrument is within a range of 0-90 degrees; or an articulation angle of the instrument is within a range of 90-180 degrees. an articulation of an articulating wrist of the instrument is above an articulation threshold; a change in the articulation of the articulating wrist is above an articulation change threshold; or a rate of change of the articulation of the articulating wrist is above an angular velocity threshold.

43. The non-transitory machine-readable medium of claim 42, wherein the method further comprises dithering the one or more control signals while the one or more articulation conditions exist.

44. The non-transitory machine-readable medium of claim 43, wherein the method further comprises continuing to dither the one or more control signals for a period of time after the one or more articulation conditions no longer exist.

45. The non-transitory machine-readable medium of any of claims 26-38, wherein determining that the actuation of the one or more actuators should be dithered comprises determining whether one or more grasping conditions exist, the one or more grasping conditions comprising: the force applied by the first jaw and second jaw to grasp the material is below a first force threshold; the force applied by the first jaw and second jaw to grasp the material is above a second force threshold; or a change in the force applied by the first jaw and second jaw to grasp the material is above a force change threshold.

46. The non-transitory machine-readable medium of claim 45, wherein the controller is further configured to dither the one or more control signals while the one or more grasping conditions exist.

47. The non-transitory machine-readable medium of claim 46, wherein the method further comprises continuing to dither the one or more control signals for a period of time after the one or more grasping conditions no longer exist.

48. The non-transitory machine-readable medium of any of claims 26-38, wherein the method further comprises: receiving a command to control the instrument; and in response to receiving the command, determining whether the actuation of the one or more actuators should be dithered.

49. The non-transitory machine-readable medium of claim 48, wherein the command is: a command to change an articulation of an articulating wrist of the instrument; a command to apply cutting energy, sealing energy, or both cutting and sealing energy to the grasped material using one or more electrodes on the first jaw, the second jaw, or both the first jaw and the second jaw; or a command to change the force applied to grasp the material.

50. The non-transitory machine-readable medium of claim 48, wherein the method further comprises executing the command using the instrument. ​

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