WO2025049463A1

WO2025049463A1 - Systems and methods for control of a surgical system

Info

Publication number: WO2025049463A1
Application number: PCT/US2024/044018
Authority: WO
Inventors: Clifford N. BARGAR; J. Scot Hart; Ashwinram Suresh; Lawton N. Verner
Original assignee: Intuitive Surgical Operations, Inc.
Priority date: 2023-08-29
Filing date: 2024-08-27
Publication date: 2025-03-06

Abstract

Systems and methods are provided for control of a surgical system. Accordingly, a controller of the surgical system detects a number of instances of a deviation of a sensor signal from a design sensor signal. An error rate is then determined for the sensor signal, and on a condition that the error rate exceeds an error rate threshold, an error tolerant mode is entered in which a normal operational mode of the surgical system is stopped and a resolution timer is initiated. If a resolution signal is received prior to the expiration of the resolution timer, the normal operational mode is resumed, but if the resolution signal is not received prior to the expiration of the resolution timer, a fault mode is entered.

Description

SYSTEMS AND METHODS FOR CONTROL OF A SURGICAL SYSTEM

Cross-Reference to Related Applications

[0001] This application claims benefit of priority to U.S. Provisional Application Serial No. 63/535,156, entitled “Systems and Methods for Control of a Surgical System,” filed August 29, 2023, which is incorporated herein by reference in its entirety.

Background

[0002] The embodiments described herein relate to surgical systems, and more specifically to teleoperated surgical systems. More particularly, the embodiments described herein relate to systems and methods that limit instances of a system fault mode being triggered in response to an error condition and eliminate certain instances of system fault mode entry when the error condition can be efficiently resolved.

[0003] Known techniques for Minimally Invasive Surgery (MIS) employ instruments to manipulate tissue that can be either manually controlled or controlled via hand-held or mechanically grounded teleoperated medical systems that operate with at least partial computer-assistance (“telesurgical systems”). Many known MIS instruments include a therapeutic or diagnostic end effector (e.g., forceps, a cutting tool, or a cauterizing tool) mounted on an optional wrist mechanism at the distal end of a shaft. During an MIS procedure, the end effector, wrist mechanism, and the distal end of the shaft are typically inserted into a small incision or a natural orifice of a patient via a cannula to position the end effector at a work site within the patient’s body. The optional wrist mechanism can be used to change the end effector’s position and orientation with reference to the shaft so as to perform a desired procedure at the work site. In known instruments, motion of the instrument as a whole provides mechanical degrees of freedom (DOFs) for movement of the end effector, and the wrist mechanisms generally provide the desired DOFs for movement of the end effector with reference to the shaft of the instrument. For example, for forceps or other grasping tools, known wrist mechanisms are able to change the pitch and yaw of the end effector with reference to the shaft. A wrist may optionally provide a roll DOF for the end effector, or the roll DOF may be implemented by rolling the shaft. An end effector may optionally have additional mechanical DOFs, such as grip or knife blade motion. In some instances, wrist and end effector mechanical DOFs may be combined. For example, U.S. Patent No. 5,792,135 (filed May 16, 1997) discloses a mechanism in which wrist and end effector grip DOFs are combined.

[0004] Known methods for controlling robotic surgical systems can include monitoring for error conditions (e.g., a collision between portions of the system, sensor signal errors, system function errors, and/or other undesirable conditions) and then producing a fault code (placing system into a fault mode) in response to detection of the error condition. When the system is transitioned into a fault mode, the process for resolving the fault is often time consuming and frustrating for the clinical operator. For example, some known methods of control place the system “out of following” (i.e., breaking the teleoperated control between user input and instrument motion), thereby eliminating the ability of the user to move the instrument via the manipulator. In some instances, resolving a fault code when the system is in a fault mode (also referred to as a fault state) can include requiring an operator access and use an instrument release kit (“IRK”). The IRK is used to manually release/open the end effector (e g., to release tissue that may be stuck in a “gripped” state). This process can include multiple manual steps. In some instances, returning the system to a normal operational condition can involve the removal of the instrument from the manipulator, a manual reset of the manipulator of the system, and/or the replacement of the instrument.

[0005] With increased complexity of instruments, there are many more potential fault/error conditions that can occur, and that could result in the system entering a fault mode. For example, known force sensing surgical instruments and the associated telesurgical systems may deliver haptic feedback and/or force feedback during a MIS procedure to a surgeon performing the procedure. The feedback may increase the surgeon’s immersion, realism, and intuitiveness while using the system during the procedure. For effective haptics rendering and accuracy, force sensors may be placed on a medical instrument and as close to the anatomical tissue interaction as possible. One approach is to include a force sensor unit having electrical sensor elements (e.g., strain sensors or strain gauges) at a distal end of a medical instrument shaft to measure strain imparted to the medical instrument. The measured strain can be used to determine the force imparted to the medical instrument and as input upon which the desired feedback may be generated. But, error conditions can include loss or delay of electrical communications with the sensors (e.g., due to collision of the instrument with surrounding structure, including portions of the sysetm), damaged sensors causing erroneous readings, and other issues that can cause spurious signals.

[0006] With the increased amount of potential error conditions, the likelihood of the system being placed into a fault mode, and the corresponding disruption to the intended procedure, is increased. Therefore, new and improved systems and methods for control of a surgical system that limit instances of the fault mode being triggered and eliminate certain instances where the error condition can be efficiently resolved are desired.

Summary

[0007] This summary introduces certain aspects of the embodiments described herein to provide a basic understanding. This summary is not an extensive overview of the inventive subject matter, and it is not intended to identify key or critical elements or to delineate the scope of the inventive subject matter.

[0008] The systems and methods described herein facilitate the accommodation of certain error signals through the use of an error tolerant mode and, in some instances, a retry mode. The error tolerant mode provides an intermediate state/mode for the computer-assisted system that is between the normal operational mode of the computer-assisted system and a fault mode of the computer-assisted system. The error tolerant mode provides a delay between an error indication and the transition to the fault mode, during which the controller of the computer-assisted system can receive an indication of a normal termination of the operational mode, such as the indication that the surgical instrument has been removed. Upon receipt of the indication of the normal termination, the computer-assisted system can be restored to the normal operational mode without requiring at least a partial restart of the computer-assisted system, as would be required if the fault mode were triggered. In some instances, a retry mode can be implemented from the error tolerant mode. In the retry mode, the operator of the computer-assisted system can implement potentially corrective measures (e.g., repositioning a portion of the computer-assisted system) in an attempt to resolve the error indication without the system entering the fault mode. [0009] In one aspect, the present disclosure is directed to a computer-assisted system that includes an instrument supported by a manipulator unit. A sensor unit is operably coupled to the instrument and configured to generate a sensor signal. An input device is operably coupled to the instrument and the manipulator unit. A controller is operably coupled to the manipulator unit, the input device, and the sensor unit. The controller includes at least one processor and is configured to execute a set of operations. The set of operations includes operating a portion of the computer- assisted system in a normal operational mode, and receiving the sensor signal corresponding to an operating condition of the instrument from the sensor unit. A set of instances of a deviation of the sensor signal from a design sensor signal is detected. The set of operations also includes determining an error rate for the sensor signal based in part on the set of instances. On a condition that the error rate exceeds an error rate threshold, an error tolerant mode, in which the normal operational mode of the computer-assisted system is stopped, is entered, and a resolution timer is initiated. On a condition that a resolution signal is received prior to an expiration of the resolution timer, the set of operations includes resuming the normal operational mode of the computer- assisted system. On a condition that the resolution signal is not received prior to the expiration of the resolution timer, the set of operations includes entering a fault mode in which at least a partial restart of the computer-assisted system is required to restore the normal operational mode.

[0010] In some embodiments, the set of operations includes determining the error rate for the sensor signal by establishing a rolling sample window that has a specified quantity of sampling intervals. Additionally, a quantity of the sampling intervals that are error intervals is determined. The quantity of error intervals is the quantity of sampling intervals in the rolling sampling window that correspond to an instance of the set of instances of the deviation of the sensor signal. Further, determining the error rate for the error signal includes determining the error rate as a ratio of the quantity of error intervals to the quantity of sampling intervals.

[0011] In some embodiments, each sampling interval corresponds to a processor cycle.

[0012] In some embodiments, the processor is configured to have a cycle rate of 1.3 kilohertz, and the error rate threshold corresponds to five percent of the sampling intervals (e.g., 50 error intervals per 1000 sampling intervals). [0013] In some embodiments, the resolution timer has a duration that corresponds to a portion of the sampling intervals of the rolling sample window.

[0014] In some embodiments, the resolution signal is signal indicating instrument removal.

[0015] In some embodiments, the set of operations includes delivering a force feedback to the input device at a magnitude corresponding to a preceding normal sensor signal on a condition that the error rate is less than the error rate threshold and at least one of the set of instances of deviation is detected.

[0016] In some embodiments, the set of operations includes entering a retry mode from the error tolerant mode on a condition that the resolution signal is not received prior to the expiration of the resolution timer. The retry mode facilitates an execution of a resolution attempt.

[0017] In some embodiments, entering the retry mode includes establishing a portion of the computer-assisted system in a reduced operational mode. The reduced operational mode facilitates the resolution attempt by an operator of the computer-assisted system.

[0018] In some embodiments, the reduced operational mode corresponds to an operational mode in which an input to the input device results in an alteration of a condition of at least one of the manipulator unit or the instrument. Delivery of a force feedback to the input device is precluded in the reduced operational configuration.

[0019] In some embodiments, entering the retry mode includes initiating a retry timer following the establishment of the portion of the computer-assisted system in the reduced operational mode. Additionally, on a condition that the error rate is below the error rate threshold prior to an expiration of the retry timer, resuming the normal operational mode of the computer- assisted system. On a condition that the error rate is above the error rate threshold upon the expiration of the retry timer, entering the fault mode.

[0020] In some embodiments, the retry timer has a duration of greater than two seconds and less than three seconds following the establishment of the portion of the computer-assisted system in the reduced operational mode. [0021] In some embodiments, the set of operations further includes extending the retry timer on a condition that the error rate has a decreasing trend upon the expiration of the retry timer.

[0022] In some embodiments, the resolution attempt is a first resolution attempt. Additionally, the retry mode facilitates a second resolution attempt and includes an attempt count limit that corresponds to a maximum number of permitted resolution attempts.

[0023] In some embodiments, the attempt count limit is reset following a specified delay interval.

[0024] In some embodiments, the input device includes a graphical user interface. The retry mode is implemented in response to an input provided to the controller via the graphical user interface.

[0025] In one aspect, the present disclosure is directed to a computer-assisted system that includes one or more memories, in which instructions are stored, and one or more controllers operatively coupled to the one or more memories. A normal operational mode of the computer- assisted system is defined, in which a human user of the computer-assisted system operates the computer-assisted system to carry out a surgical procedure. A fault mode of the computer-assisted system is defined, in which the human user is required to perform at least a partial restart of the computer-assisted system to enter the normal operational mode of the computer-assisted system. A normal operational mode of a surgical instrument of the computer-assisted system is defined. A normal operational mode of a feature of the surgical instrument is defined. An error tolerant mode of the computer-assisted system is defined. A retry mode of the computer-assisted system is defined. The instructions cause the one or more controllers to execute actions. The actions include operating the computer-assisted system in the normal operational mode of the computer-assisted system. On a condition in which the one or more controllers have received an indication of a predefined error associated with the normal operational mode of the feature of the surgical instrument, the actions include stopping the normal operational mode of the computer-assisted system and entering the error tolerant mode of the computer-assisted system but not entering the fault mode of the computer-assisted system. On a condition in which the computer-assisted system has entered the error tolerant mode and the one or more controllers have received an indication of a normal termination of the normal operational mode of the surgical instrument before expiration of an error tolerant mode delay time, the actions include resuming the normal operational mode of the computer-assisted system. On a condition in which the computer-assisted system has entered the error tolerant mode, the one or more controllers have not received the indication of the normal termination of the normal operational mode of the surgical instrument before expiration of the error tolerant mode delay time, and the retry mode is unavailable for the predefined error associated with the normal operational mode of the feature of the surgical instrument, the actions include entering the fault mode of the computer-assisted system. On a condition in which the computer- assisted system has entered the error tolerant mode, the one or more controllers have not received the indication of the normal termination of the normal operational mode of the surgical instrument before expiration of the error tolerant mode delay time, and the retry mode is available for the predefined error associated with the normal operational mode of the feature of the surgical instrument, the actions include entering the retry mode of the computer-assisted system. On a condition in which the computer-assisted system has entered the retry mode and the one or more controllers have received an indication of a correction by the human user of the error associated with the normal operational mode of the feature of the surgical instrument, the actions include resuming the normal operational mode of the computer-assisted system. On a condition in which the computer-assisted system has entered the retry mode and the one or more controllers have not received the indication of the correction by the human user of the error associated with the normal operational mode of the feature of the surgical instrument, the actions include entering the fault mode of the computer-assisted system.

[0026] In some embodiments, the predefined error associated with the normal operational mode of the feature of the surgical instrument is a communication error between the feature of the surgical instrument and the one or more controllers.

[0027] In some embodiments, the actions further include providing a moving window of a set of samples of a signal associated with the feature of the surgical instrument. The predefined error associated with the normal operational mode of the feature of the surgical instrument is a condition in which a predefined non-zero number of individual samples of the moving window of the set of samples exceed a predefined tolerance. [0028] In some embodiments, the error tolerant mode delay time is a time sufficient to make a predefined number of samples of a signal associated with the feature of the surgical instrument.

[0029] In some embodiments, the indication of the normal termination of the normal operational mode of the surgical instrument is an indication the surgical instrument has been removed from the computer-assisted system.

[0030] In some embodiments, the feature of the surgical instrument is a force sensor positioned to sense a force applied at a distal end of the surgical instrument.

[0031] In some embodiments, the computer-assisted system includes a user interface; and the instructions cause the one or more controllers to execute actions. The actions include capturing a steady-state user interface output, which is associated with the feature of the surgical instrument, and which is provided via the user interface to the human user immediately prior to entering the error tolerant mode, and on the condition the computer-assisted system has entered the error tolerant mode, providing the steady-state user interface output to the human user during the error tolerant mode.

[0032] In some embodiments, the feature of the surgical instrument is a force sensor positioned to sense a force applied at a distal end of the surgical instrument; the steady-state user interface output is a force output to the human user; and the force output to the human user is associated with the force applied at the distal end of the surgical instrument.

[0033] In some embodiments, the feature of the surgical instrument is an image sensor positioned to capture an image at a distal end of the surgical instrument; the steady-state user interface output is an image output to the human user; and the image output to the human user is associated with the image at the distal end of the surgical instrument.

[0034] In some embodiments, the normal operating mode of the computer-assisted system is further defined, in which motion of the surgical instrument follows motion of an input device operated by the human user.

[0035] In some embodiments, the computer-assisted system includes the surgical instrument. [0036] In some embodiments, a normal operational mode of a second feature of the surgical instrument is defined. The instructions cause the one or more controllers to execute actions that include operating the second feature of the surgical instrument in the normal operational mode of the second feature of the surgical instrument during the error tolerant mode of the computer- assisted system.

[0037] In some embodiments, a normal operational mode of a second feature of the surgical instrument is defined. The instructions cause the one or more controllers to execute actionsthat include operating the second feature of the surgical instrument in the normal operational mode of the second feature of the surgical instrument during the retry mode of the computer-assisted system.

[0038] These and other inventive features, aspects, and advantages will become better understood with reference to the following description and drawings.

Brief Description of the Drawings

[0039] FIG. 1 is a plan view of a computer-assisted system configured as a minimally invasive teleoperated medical system according to an embodiment being used to perform a medical procedure such as surgery.

[0040] FIG. 2 is a perspective view of a user control console of the minimally invasive teleoperated surgery system shown in FIG. 1.

[0041] FIG. 3 is a perspective view of an optional auxiliary unit of the minimally invasive teleoperated surgery system shown in FIG. 1.

[0042] FIG. 4 is a front view of a manipulator unit, including a plurality of instruments, of the minimally invasive teleoperated surgery system shown in FIG. 1 .

[0043] FIG. 5 is an illustration of a portion of the teleoperated system of FIG. 1, illustrating an instrument carriage of the manipulator unit, according to an embodiment.

[0044] FIG. 6 is a perspective view of an instrument according to an embodiment. [0045] FIG. 7 is a side view of a portion of the medical device of FIG. 6 with an outer shaft removed.

[0046] FIG. 8 is a flow chart of a set of operations or control of a surgical system.

[0047] FIG. 9 is a flow chart of a set of operations or control of a surgical system.

[0048] FIG. 10 is a schematic illustration of a controller for use with a minimally invasive teleoperated surgery system according to an embodiment.

Detailed Description

[0049] Generally, the present disclosure is directed to systems and methods for controlling a surgical system (system), such as a minimally invasive teleoperated surgery system. In particular, the systems and methods described herein facilitate the accommodation of certain error signals through the use of an error tolerant mode and, in some instances, a retry mode. The error tolerant mode establishes a process delay in which the error signal can be overridden by an indication of a normal termination. The retry mode, when available, can restore limited functionality to the system to provide an operator the opportunity to resolve the error condition via a control input and/or other similar interaction with the system.

[0050] As described herein, the error tolerant mode provides an intermediate mode (e g., an intermediate state) for the surgical system that slows or precludes a system transition directly from a normal operational mode to a fault mode upon on the detection of an error condition. In other words, the error tolerant mode provides a delay (e.g., a pause) between an error indication and the transition to the fault mode. During this delay, the controller of the surgical system can receive an indication of a normal termination of the operational mode, such as the indication that the surgical instrument has been removed. Upon receipt of the indication of the normal termination, the surgical system can be restored to the normal operational mode without requiring at least a partial restart of the surgical system, as would be required if the fault mode were initiated. For example, due to various cycling rates and/or control loop implementations, in some instances, the controller of the system can detect a loss of communication with a force sensor unit, which can be indicative of an error condition, prior to receiving an indication that the instrument has been removed from the system, which also severs communication between the controller and the force sensor unit as part of normal operations. Without the error tolerant mode, the system may assess the loss of communication as an error condition and enters the fault mode, which requires at least a partial restart of the surgical system to restore the normal operational mode. However, the error tolerant mode pauses the system for a specified duration so that the indication of instrument removal can be received. As loss of communication concurrent within instrument removal is a normal operational condition, the system can be restored to the normal operation mode without requiring a system restart. Such a restoration of the normal operational mode without requiring system restart can be less disruptive to the intended procedure and thus more desirable to the operator.

[0051] As further described herein, in some instances, a retry mode can be implemented from the error tolerant mode. In the retry mode, the operator of the surgical system can implement potentially corrective measures in an attempt to resolve the error indication rather than the system entering the fault mode and requiring at least a partial restart. In the retry mode, the system can be placed in a reduced operational mode (e.g., a reduced operational configuration) in which the operator can perform at least one of a defined set of potentially corrective actions. For example, a loss of communication with a sensor can result in the instrument and/or a supporting manipulator arm is positioned in such a way that disrupts the communicative coupling between instrument and the controller. Accordingly, in the retry mode, the operator can be permitted to reposition the instrument and/or the manipulator arm. The repositioning can resolve the disruption to the communicative coupling thereby restoring communication between the sensor and the controller. With the communication being restored, the system can resume the normal operation mode, and the at least partial system restart is avoided.

[0052] As used herein, the term “about” when used in connection with a referenced numeric indication means the referenced numeric indication plus or minus up to 10 percent of that referenced numeric indication. For example, the language “about 50” covers the range of 45 to 55. Similarly, the language “about 5” covers the range of 4.5 to 5.5.

[0053] As used in this specification and the appended claims, the word “distal” refers to direction towards a work site, and the word “proximal” refers to a direction away from the work site. Thus, for example, the end of a tool that is closest to the target tissue would be the distal end of the tool, and the end opposite the distal end (i.e., the end manipulated by the user or coupled to the actuation shaft) would be the proximal end of the tool.

[0054] Further, specific words chosen to describe one or more embodiments and optional elements or features are not intended to limit the invention. For example, spatially relative terms — such as “beneath”, “below”, “lower”, “above”, “upper”, “proximal”, “distal”, and the like — may be used to describe the relationship of one element or feature to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different positions (i.e., translational placements) and orientations (i.e., rotational placements) of a device in use or operation in addition to the position and orientation shown in the figures. For example, if a device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be “above” or “over” the other elements or features. Thus, the term “below” can encompass both positions and orientations of above and below. A device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Likewise, descriptions of movement along (translation) and around (rotation) various axes includes various spatial device positions and orientations. The combination of a body’s position and orientation define the body’s pose (e.g., a kinematic pose).

[0055] Similarly, geometric terms, such as “parallel”, “perpendicular”, “round”, or “square”, are not intended to require absolute mathematical precision, unless the context indicates otherwise. Instead, such geometric terms allow for variations due to manufacturing or equivalent functions. For example, if an element is described as “round” or “generally round,” a component that is not precisely circular (e.g., one that is slightly oblong or is a many-sided polygon) is still encompassed by this description.

[0056] In addition, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context indicates otherwise. The terms “comprises”, “includes”, “has”, and the like specify the presence of stated features, steps, operations, elements, components, etc. but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, or groups.

[0057] Unless indicated otherwise, the terms apparatus, medical device, instrument, and variants thereof, can be interchangeably used. [0058] Inventive aspects are described with reference to a computer-assisted system (e.g., a teleoperated surgical system). An example architecture of such a teleoperated surgical system is the da Vinci® surgical system commercialized by Intuitive Surgical, Inc., Sunnyvale, California. Knowledgeable persons will understand, however, that inventive aspects disclosed herein may be embodied and implemented in various ways, including computer-assisted, non-computer-assisted, and hybrid combinations of manual and computer-assisted embodiments and implementations. Implementations are merely presented as examples, and they are not to be considered as limiting the scope of the inventive aspects disclosed herein. As applicable, inventive aspects may be embodied and implemented in both relatively smaller, hand-held, hand-operated devices and relatively larger systems that have additional mechanical support.

[0059] FIG. 1 is a plan view illustration of a computer-assisted system (“system”) 1000 that operates with at least partial computer assistance. The system 1000 can, for example, be configured as a teleoperated surgical system (e.g., a “telesurgical system”). When configured as a telesurgical system, the system 1000 and its components can be considered medical devices. In some embodiments, the system 1000 is a Minimally Invasive Robotic Surgical (MIRS) system used for performing a minimally invasive diagnostic or surgical procedure on a patient P who is lying on an operating table 1010. The system can have any number of components, such as a user control unit 1100 for use by an operator of the system, such as a surgeon or other skilled clinician S (e.g., an operator), during the procedure. The system 1000 can further include a manipulator unit 1200 (popularly referred to as a surgical robot) and an optional auxiliary equipment unit 1150. The manipulator unit 1200 can include an arm assembly 1300 and a surgical instrument tool assembly removably coupled to the arm assembly. The manipulator unit 1200 can manipulate at least one removably coupled medical instrument (instrument) 1400 through a minimally invasive incision in the body or natural orifice of the patient P while the surgeon S views the surgical site and controls movement of the instrument 1400 through control unit 1100. An image of the surgical site is obtained by an endoscope (not shown), such as a stereoscopic endoscope, which can be manipulated by the manipulator unit 1200 to orient the endoscope. The auxiliary equipment unit 1150 can be used to process the images of the surgical site for subsequent display to the surgeon S through the user control unit 1100. The number of instruments 1400 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 instruments 1400 being used during a procedure, an assistant removes the instrument 1400 from the manipulator unit 1200 and replaces it with another instrument 1400 from a tray 1020 in the operating room. Although shown as being used with the instruments 1400, any of the instruments described herein can be used with the system 1000.

[0060] FIG. 2 is a perspective view of the control unit 1100. The user control unit 1100 includes a left eye display 1112 and a right eye display 1114 for presenting the surgeon S with a coordinated stereoscopic view of the surgical site that enables depth perception. The left eye display 1112 and the right eye display 1114 can also be used to present the surgeon S with information about the system 1000. The information presented to the surgeon S can be presented in the form of a graphical user interface through which inputs can be provided to the controller 1800 (FIG. 10). The user control unit 1100 further includes one or more input control devices 1116 (input device), which in turn cause the manipulator unit 1200 (shown in FIG. 1) to manipulate one or more tools. The input devices 1116 provide at least the same degrees of freedom as instruments 1400 with which they are associated to provide the surgeon S with telepresence, or the perception that the input devices 1116 are integral with (or are directly connected to) the instruments 1400. In this manner, the user control unit 1100 provides the surgeon S with a strong sense of directly controlling the instruments 1400. To this end, position, force, strain, or tactile feedback sensors (not shown) or any combination of such sensations, from the instruments 1400 back to the surgeon's hand or hands through the one or more input devices 1116.

[0061] The user control unit 1100 is shown in FIG. 1 as being in the same room as the patient so that the surgeon S can directly monitor the procedure, be physically present if necessary, and speak to an assistant directly rather than over the telephone or other communication medium. In other embodiments, however, the user control unit 1100 and the surgeon S can be in a different room, a completely different building, or other location remote from the patient, allowing for remote surgical procedures.

[0062] FIG. 3 is a perspective view of the auxiliary equipment unit 1150. The auxiliary equipment unit 1150 can be coupled with the endoscope (not shown) and can include one or more processors to process captured images for subsequent display, such as via the user control unit 1100, or on another suitable display located locally (e.g., on the unit 1150 itself as shown, on a wall-mounted display) and/or remotely. For example, where a stereoscopic endoscope is used, the auxiliary equipment unit 1150 can process the captured images to present the surgeon S with coordinated stereo images of the surgical site via the left eye display 1112 and the right eye display 1114. 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 to compensate for imaging errors of the image capture device, such as optical aberrations.

[0063] FIG. 4 shows a front perspective view of the manipulator unit 1200. The manipulator unit 1200 includes the components (e.g., arms, linkages, motors, sensors, and the like) to provide for the manipulation of the instruments 1400 and an imaging device (not shown), such as a stereoscopic endoscope, used for the capture of images of the site of the procedure. Specifically, the instruments 1400 and the imaging device can be manipulated by teleoperated mechanisms having one or more mechanical joints. Moreover, the instruments 1400 and the imaging device are positioned and manipulated through incisions or natural orifices in the patient P in a manner such that a center of motion remote from the manipulator and typically located at a position along the instrument shaft is maintained at the incision or orifice by either kinematic mechanical or software constraints. In this manner, the incision size can be minimized.

[0064] FIG. 5 is a perspective view of a portion of an arm assembly 1300 and an instrument carriage 1330 to which an instrument 1400 can be removably coupled. The instrument carriage 1330 includes teleoperated actuators (e.g., motors 1340 with coupled drive discs 1320) to provide motions to the instrument 1400, which translates into a variety of movements of a tool or tools at a distal end portion 1402 (FIG. 6) of the instrument 1400. The arm assembly 1300 includes a connecting portion 1324 in which the instrument carriage 1330 can be coupled The instrument, carriage 1330 may be translatable relative to the arm assembly 1300, for example, along an insertion axis extending between a proximal end and a distal end of the arm assembly 1300 for insertion and removal of the instrument into a patient. The translation of the instrument carriage 1330 can develop a corresponding linear motion, relative to a longitudinal axis (e.g., in a distal or proximal direction) of a distal end portion 1402 (FIG. 6) of the instrument 1400. In addition, the arm assembly 1300 can provide for additional degrees of freedom to orient and position the instrument carriage 1330 and instrument 1400 at a desired location. When an instrument 1400 is coupled to the instalment carriage 1330. input provided by a surgeon S to the user control unit 1100 (a ‘■''master’' command) is translated into a corresponding action by the instrument 1400 (a “slave” response) via drive discs 1320 of the instrument carriage 1330 that are operatively coupled instrument discs (FIG. 6) on the instrument 1400.

[0065] The instrument carriage 1330 includes a carriage interface that includes drive discs 1320 that are configured to be operatively coupled with instrument discs 1474 at a drive member interface. In embodiments utilizing a sterile adapter or other similar structure, the drive discs 1320 may be matingly coupled to couplers of the instrument sterile adapter. The instrument carriage 1330 also includes an indentation or cutout region 1310 in which the instrument shaft (shaft) 1410 (FIG. 6) of the instrument 1400 can extend when the instrument 1400 is supported by the manipulator unit 1200. In some embodiments, the drive discs 1320 of the instrument carriage 1330 may be directly coupled to inputs of the instrument discs 1474 of the instrument 1400 without an intermediary sterile adapter.

[0066] In some embodiments, the instrument carriage 1330 can include a roll-drive disc 1350. The roll-drive disc 1350 is configured to be operatively coupled to a roll-drive instrument disc 1476 to generate a roll motion of the distal end portion 1402 of the instrument 1400 about a longitudinal (e.g., shaft) axis of the instrument 1400. The roll motion has a roll range of motion defined between a first roll limit and a second roll limit. For example, the roll range of motion can include up to 360 degrees (e.g., 350 degrees) of roll in a clockwise direction from a neutral roll orientation (e.g., a zero-degree position) to the first roll limit and up to 360 degrees (e.g., 350 degrees) of roll in a counterclockwise direction from the neutral roll orientation to a second roll limit. Accordingly, the roll range of motion can include 720 degrees (e.g., 700 degrees) of roll from the first roll limit, through the neutral roll orientation to the second roll limit.

[0067] Referring now to FIGS. 6 and 7, a perspective view of the instrument 1400 is depicted in FIG. 6, and a side view of a portion of the instrument 1400 with an outer shaft portion removed is depicted in FIG. 7. In some embodiments, the instrument 1400 or any of the components therein are optionally parts of a surgical system that performs surgical procedures, and which can include a manipulator unit, a series of kinematic linkages, a set of cannulas, or the like. The instrument 1400 (and any of the instruments described herein) can be used in any suitable surgical system, such as the system 1000 shown and described above. As shown in FIG. 6, the instrument 1400 defines includes a proximal mechanical structure 1470, a shaft 1410, a distal end portion 1402, and a set of cables (not shown). The cables function as tension elements that couple the proximal mechanical structure 1470 to the distal end portion 1402. In some embodiments, the distal end portion 1402 includes a distal wrist assembly 1500 and a distal end effector 1460. The instrument 1400 is configured such that movement of one or more of the cables produces movement of the end effector 1460 (e.g., pitch, yaw, or grip) about axes of a beam coordinate system.

[0068] Moreover, although the proximal mechanical structure 1470 is shown as including capstans 1472, in other embodiments, a mechanical structure can include one or more linear actuators that produce translation (linear motion) of a portion of the cables. Such proximal mechanical structures can include, for example, a gimbal, a lever, or any other suitable mechanism to directly pull (or release) an end portion of any of the cables. For example, in some embodiments, the proximal mechanical structure 1470 can include any of the proximal mechanical structures or components described in U.S. Patent Application Pub. No. US 2015/0047454 Al (filed Aug. 15, 2014), entitled “Lever Actuated Gimbal Plate,” or U.S. Patent No. US 6,817,974 B2 (filed Jun. 28, 2001), entitled “Surgical Tool Having Positively Positionable Tendon- Actuated Multi-Disc Wrist Joint,” or U.S. Patent No. US 6,312,435 Bl (filed Oct. 8, 1999), entitled “Surgical Instrument with Extended Reach for Use in Minimally Invasive Surgery,” each of which is incorporated herein by reference in its entirety.

[0069] The shaft 1410 can be any suitable elongated shaft that is coupled to the wrist assembly 1500 and to the proximal mechanical structure 1470. Specifically, the shaft 1410 includes a proximal end 1411 that is coupled to the proximal mechanical structure 1470, and a distal end portion 1412 that is coupled to the wrist assembly 1500 (e.g., a proximal link of the wrist assembly 1500). The shaft 1410 defines a passageway or series of passageways through which the cables and other components (e.g., electrical wires, ground wires, or the like) can be routed from the proximal mechanical structure 1470 to the wrist assembly 1500. In some embodiments, the shaft 1410 can be formed, at least in part with, for example, an electrically conductive material such as stainless steel. In such embodiments, the shaft may include any of an inner insulative cover or an outer insulative cover. Thus, the shaft 1410 can be a shaft assembly that includes multiple different components. For example, the shaft 1410 can include (or be coupled to) a spacer that provides the desired fluid seals, electrical isolation features, and any other desired components for coupling the wrist assembly 1500 to the shaft 1410. Similarly stated, although the wrist assembly 1500 (and other wrist assemblies or links described herein) are described as being coupled to the shaft 1410, it is understood that any of the wrist assemblies or links described herein can be coupled to the shaft via any suitable intermediate structure, such as a spacer and a cable guide, or the like.

[0070] As depicted in FIG. 7, the instrument 1400 includes a force sensor unit 1850 including a beam 1852, with one or more strain sensors 1860. The strain sensor 1860 can include a set of strain gauges (e.g., tension strain gauge resistor(s) or compression strain gauge resistor(s)) arranged as at least one bridge circuit (e.g., Wheatstone bridges) mounted on a surface along the beam 1852. In some embodiments, the end effector 1460 can be coupled at a distal end portion 1854 of the beam 1852 (e.g., at a distal end portion 1402 of the surgical instrument 1400) via the wrist assembly 1500. The shaft 1410 includes a distal end portion 1412 that is coupled to a proximal end portion 1856 of the beam 1852. In some embodiments, the distal end portion 1412 of the shaft 1410 is coupled to the proximal end portion 1856 of the beam 1852 via another coupling component (such as an anchor or coupler, not shown). In some embodiments, the force sensor unit 1850 can include any of the structures or components described in U.S. Patent Application Pub. No. US 2020/0278265 Al (filed May. 13, 2020), entitled “Split Bridge Circuit Force Sensor,” which is incorporated herein by reference in its entirety.

[0071] In some embodiments, the end effector 1460 can include at least one tool member 1462 having a contact portion configured to engage or manipulate a target tissue during a surgical procedure. For example, in some embodiments, the contact portion can include an engagement surface that functions as a gripper, cutter, tissue manipulator, or the like. In other embodiments, the contact portion can be an energized tool member that is used for cauterization or electrosurgical procedures. The end effector 1460 may be operatively coupled to the proximal mechanical structure 1470 such that the tool member 1462 rotates relative to shaft 1410. In this manner, the contact portion of the tool member 1462 can be actuated to engage or manipulate a target tissue during a surgical procedure. The tool member 1462 (or any of the tool members described herein) can be any suitable medical tool member. Moreover, although only one tool member 1462 is identified, as shown, the instrument 1400 can include two tool members that cooperatively perform gripping or shearing functions. In other embodiments, an end effector can include more than two tool members.

[0072] In some embodiments, the system 1000 includes the instrument 1400 supported by the manipulator unit 1200. An input device 1116 of the user control unit 1100 is operably coupled to the instrument 1400 and the manipulator unit 1200. A sensor unit, such as the force sensor unit 1850, can be operably coupled to the instrument 1400 and configured to generate a sensor signal SSi (see FIG. 8). In some embodiments, the sensor unit can be operably coupled to any additional component of the system 1000, such as the manipulator unit 1200. The sensor signal SSi can correspond to an operating condition of the system 1000 (e.g., the instrument 1400). For example, in an embodiment wherein the force sensor unit 1850 is coupled to the instrument 1400, the sensor signal SSi can be indicative of a load affecting the end effector 1460. However, in other embodiments, the sensor signal SSi can correspond to operating conditions, such as position, load, velocity, temperature, electrical state, and/or operative state, of other components of the system 1000, such as the arms of the manipulator unit 1200.

[0073] The system 1000 also includes a controller 1800 (FIG. 10) operably coupled to the manipulator unit 1200, the input device 1116, and the sensor unit 1850. As further described below, the controller 1800 includes at least one processor 1802. The controller 1800 is configured to execute a set of operations 1700 (e.g., a set of instructions contained within at least one memory device 1804), such as those operations depicted in FIG. 8. The set of operations 1700 can minimize disruptions to the intended operation of the system 1000 by limiting instances of a system fault mode being triggered in response to an error condition and eliminating certain instances of fault mode entry where the error condition can be efficiently resolved. It should be appreciated that the set of operations 1700 can be implemented as a method for controlling the system 1000 and can include actions performed by an operator of the system 1000.

[0074] As depicted in FIG. 8 at 1702, in some embodiments, the set of operations 1700 includes operating a portion of the system 1000 (e.g., a single instrument 1400 supported by a single arm assembly 1300 of the manipulator unit 1200) in a normal operational mode. The normal operational mode can correspond to the designed operations of the system 1000 to perform the intended procedures. The normal operational mode can, for example, correspond to the operating condition of the system 1000 in the absence of an error condition. Accordingly, the set of operations 1700 can include receiving the sensor signal SSi from the sensor unit corresponding to an operating condition of a portion of the system 1000, such as the instrument 1400.

[0075] As depicted at 1704, the set of operations 1700 can include detecting a deviation of the sensor signal SSi from a design sensor signal. More particularly, the controller 1800 can detect a set of instances of the deviation of the sensor signal SSi from the design sensor signal. In some embodiments, the deviation can correspond to the absence of a sensor input (i.e., the sensor signal SSi) during a sampling interval (e.g., a processor cycle) during which the sensor input would otherwise be expected. In some embodiments, the deviation can correspond to a magnitude of the sensor signal SSi that falls outside of a predefined magnitude range. In some embodiments, the deviation can correspond to a designed error signal (e.g., a proximity alarm signal, an overload signal, or other similar signal) generated by the sensor unit.

[0076] On a condition that a set of instances of deviation of the sensor signal SSi is detected, and error rate for the sensor signal SSi is determined, at 1706, based at least in part on the set of instances. In some embodiments, the error rate can be determined by establishing a rolling sample window that has a specified quantity of sampling intervals. The controller 1800 can then determine a quantity of the sampling intervals that are error intervals. In other words, the controller 1800 can determine the number of intervals during the rolling sample window in which the sensor signal SSi deviates from the design sensor signal. Said another way, the quantity of error intervals is the quantity of sampling intervals in the rolling sampling window that correspond to instances of the deviation of the sensor signal SSi. The controller 1800 can then determine the error rate as a ratio of the quantity of error intervals to the quantity of sampling intervals. In some embodiments, the controller 1800 is, at 1708, configured to determine whether the error rate is greater than an error rate threshold.

[0077] By way of nonlimiting illustration, each sampling interval can correspond to a processor cycle and the error rate threshold can correspond to 50 cumulative error intervals per 1000 sampling intervals (five percent of the sampling intervals). The processor 1802 can, for example, be configured to have a cycle rate in a range of 1 kilohertz to 1.5 kilohertz. At a cycle rate of 1.3 kilohertz, for example, the receipt of 50 or more instances of deviation of the sensor signal from the design sensor signal in any given 0.76 seconds is indicative of an error rate that is greater than or equal to the error rate threshold. Optionally, an error interval percentage larger or smaller than five percent (e.g., a range of two percent to seven percent) of the window of sampling intervals may be used such that the larger percentage does not fail to detect erroneous signal deviations as necessary, and the smaller percentage does not yield an unacceptable amount of false positive erroneous signal deviations.

[0078] In some embodiments, the error rate may be less than the error rate threshold but at least one of the set of instances of deviation can be detected. In such embodiments, the set of operations 1700 can include delivering a force feedback to the input device 1116 at a magnitude corresponding to a preceding normal sensor signal. In other words, the controller 1800 is configured to recognize instances of deviation and disregard the erroneous data in providing the force feedback to the input device 1116. Said yet another way, the controller 1800 can be configured to ride through error conditions using previously received normal sensor signals so long as the error rate is less than the error rate threshold.

[0079] On a condition that the error rate exceeds an error rate threshold, the set of operations 1700 includes entering an error tolerant mode, at 1710. As depicted by steps 1712 and 1714, in the error tolerant mode the normal operational mode of the system 1000 is stopped and a resolution timer is initiated. Said another way, upon detecting an error rate of the sensor signal SSi that meets or exceeds the error rate threshold, the controller 1800 pauses the normal operation of a portion of the system 1000 (e.g., a single arm assembly 1300 and supported instrument 1400), thereby maintaining the portion of the system 1000 in place. In other words, the paused portion of the system 1000 can be maintained in the same position and/or orientation as that immediately preceding entry into the error tolerant mode. Other nonaffected portions of the system 1000 can be maintained in the normal operational mode while the normal operation of the affected portion of the system 1000 is halted.

[0080] The initiation of the resolution timer at 1714 establishes the system delay in which the controller 1800 can receive an indication of an intended actions (e.g., a normal termination of the normal operational mode) that resulted in the error rate and, thereby, alleviate the necessity to enter the fault mode. In some embodiments, the resolution timer can have a duration that corresponds to a portion of the sampling intervals of the rolling sampling window. For example, the resolution timer can be 30 percent or less (e.g., 20 percent, 15 percent, or 10 percent) of the sampling intervals. In embodiments wherein the sampling intervals correspond to processor cycles and, for example, the window comprises 1000 sampling intervals, the resolution timer can extend for 300 cycles or less (e.g., 200 cycles). If in such an embodiment the processor 1802 has a cycle rate of 1.3 kilohertz, then the resolution timer can be established at 0.23 seconds or less (e.g., 0.15 seconds).

[0081] As depicted at 1716, the set of operations 1700 includes determining whether a resolution signal is received prior to expiration of the resolution timer. On a condition that the resolution signal is received prior to the expiration of the resultant timer, the set of operations 1700 includes, at 1718, resuming the normal operational mode of the system 1000. The resolution signal can, for example, be an instrument removal signal indicative of the removal of the instrument 1400 from the manipulator unit 1200. Concurrent with the removal of the instrument 1400 from the supportive arm assembly 1300, the communicative coupling between the controller 1800 and a sensor (e.g., the force sensor unit 1850) can be interrupted. In some instances, the interruption of the communication with the sensor can be detected by the controller 1800 before the controller 1800 receives an indication of instrument removal, and therefore the interruption can be interpreted as an error condition. As such, without the delay provided by the error tolerant mode, the interruption of the communicative link would otherwise result in the controller 1800 placing the system 1000 in fault mode in response to the perceived error condition. But with the implementation of the error tolerant mode, the controller 1800 can receive the indication of instrument removal and restore the normal operational mode of the system 1000. In other embodiments, the resolution signal can, for example, be an operator-initiated termination signal corresponding to the deactivation of the sensor, the instrument 1400, the arm assembly 1300 supporting the instrument 1400, and/or any other involved component of the system 1000. In other words, the resolution signal can correspond to an indication of a normal termination of the normal operation mode of the system 1000.

[0082] On a condition that the resolution signal is not received prior to the expiration of the resolution timer, the set of operations 1700 includes, at 1720, entering a fault mode. In the fault mode, at least a partial restart of the system 1000 is required to restore the normal operation mode. In the fault mode, at least one system operation can be halted, and a fault signal can be generated. To restore the system 1000 to the desired normal operational mode, in some embodiments, an operator of the system 1000 is required to perform the partial restart. The partial restart can include, for example, terminating and restarting a controller process, initiating a reboot sequence, returning a portion of the system 1000 to a home or initial position and executing a recovery procedure, manually manipulating physical portions of the system 1000 followed by the execution of an initiation sequence, or other similar actions configured to resolve the fault condition and restore a normal operational mode of the portion of the system 1000.

[0083] In lieu of entering the fault mode on the condition that the resolution signal is not received prior to the expiration of the resolution timer, in some embodiments, the set of operations 1700 includes entering retry mode, at 1722, from the error tolerant mode. The retry mode facilitates the execution of one or more resolution attempts, at 1724. As such, in some embodiments, entering the retry mode includes establishing, at 1726, a portion of the system 1000 in a reduced operational mode (e.g., a reduced operational configuration). The reduced operational mode corresponds to an operational mode of the system 1000 in which an input to the input device 1116 results in an alteration of a condition, orientation, and/or position of the manipulator unit 1200, the arm assembly 1300, and/or the instrument 1400 in an attempt to resolve the error condition via an action commanded by the operator (e.g., a resolution attempt). However, certain functions, positions, and/or movements of the components of the system 1000 that would otherwise be available in the normal operational mode can be precluded in the reduced operational configuration. For example, delivery of force feedback to the input device 1116 can be limited or precluded in the reduced operational configuration, while the operator of the system 1000 repositions the arm assembly 1300 and/or the instrument 1400 during the resolution attempt.

[0084] In some embodiments, as depicted at 1728, entering the retry mode includes initiating a retry timer following the establishment of the portion of the system 1000 in the reduced operational mode. The retry timer can correspond to an interval during which at least one resolution attempt is permitted prior to the controller 1800 transitioning the system 1000 to the fault mode. In some embodiments, the retry timer has a duration of greater than two seconds and less than three seconds following the establishment of the portion of the system 1000 in the reduced operational configuration. For example, when available, the operator can elect (e.g., in response to a prompt) to enter the retry mode (e.g., via an input provided to the controller 1800 via a graphical user interface of the control unit 1100). The entry into the (e.g., the commencement of) the retry mode does not initiate the retry timer. Rather, once the retry mode has been initiated by the operator, the operator can then control the controller to place the system 1000 in the reduced operational configuration. The operator then has the finite interval of the retry timer (e.g., less than three seconds) to execute a resolution attempt via control inputs provided to the input device 1116 to, for example, reposition the arm assembly 1300 to alleviate the conditions that led to the deviation of the sensor signal SSi.

[0085] In some embodiments, following the entry into the retry mode, at 1722, the controller 1800 is configured, at 1730, to determine whether the error rate is less than the error rate threshold. On a condition that the error rate is below the error threshold prior to the expiration of the retry timer, the normal operational mode of the system 1000 is resumed, at 1718. At 1732, the controller 1800 is configured to determine whether the retry timer has expired. On a condition that the error rate is greater than equal to the error rate threshold but prior to the expiration of the retry timer, an additional resolution attempt(s) is permitted. However, on a condition that the error rate is greater than or equal to the error rate threshold upon the expiration the retry timer, the system 1000 is transitioned to the fault mode, at 1720, from which at least a partial restart of the system 1000 is required to restore the normal operational mode.

[0086] As depicted at 1734, in some embodiments, in which the error is greater than equal to the error rate threshold at the expiration of the retry timer, the controller is configured to determine whether the error rate is decreasing. Said another way, the controller 1800 can be configured to determine whether the quantity of error intervals in the rolling sample window is decreasing. In some embodiments, on a condition that the error rate has a decreasing trend upon the expiration of the retry timer, the set of operations 1700 include extending the retry timer, at 1736. By extending the retry timer, additional resolution attempts may be executed by the operator to reduce the error rate below the error rate threshold. However, on a condition that the error rate lacks a decreasing trend upon the expiration of the retry timer, the system 1000 is transitioned to the fault mode, at 1720. [0087] In addition to the retry timer, in some embodiments, the number of permitted resolution attempts may also be limited. In other words, in some embodiments, the retry mode can include an attempt count limit that corresponds to a maximum number of permitted resolution attempts. For example, the retry mode can permit the execution of six or less (e.g., 2, 3, 4, or 5) resolution attempts before the controller 1800 transitions the system 1000 to the fault mode regardless of the error rate trend. However, in some embodiments, the attempt count limit is reset following a specified delay interval.

[0088] Referring now to FIG. 9, in some embodiments, the system 1000 includes one or more memory devices 1804 in which instructions 2700 are stored. The memory device(s) 1804 are operably coupled to, or are a component of, the controller 1800 (FIG. 10). The system 1000 can also include an instrument 1400 as described herein. In embodiments, such as depicted in FIG. 9, the system 1000 has a normal operational mode in which a human user of the system 1000 operates the system 1000 to carry out a surgical procedure. The normal operational mode can, for example, correspond to a motion of the instrument 1400 that follows a motion of the input device 1116 operated by the human user. In addition to the normal operational mode, the system 1000 also has a fault mode in which the human user is required to perform at least a partial restart of the system 1000 to return the system to the normal operational mode. The system 1000 can also have an error tolerant mode and a retry mode as described herein. Additionally, the instrument 1400 and/or a feature of the instrument 1400 can have a normal operational mode consistent with the performance of the surgical procedure. In some embodiments, the feature of the instrument 1400 can, for example, be a force sensor positioned to sense a force applied at a distal end of the instrument 1400. In some embodiments, the feature of the instrument 1400 can, for example, be an image sensor positioned to capture an image at a distal end of the instrument 1400.

[0089] As shown in FIG. 9, the instructions 2700 cause the controller 1800 to execute a set of actions. The set of actions can minimize disruptions to the intended operation of the system 1000 by limiting instances of a system fault mode being triggered in response to an error condition and eliminating certain instances of fault mode entry where the error condition can be efficiently resolved. It should be appreciated that the set of actions can be implemented as a method for controlling the system 1000 and can include actions performed by a user of the system 1000. [0090] As depicted in FIG. 9 at 2702, in some embodiments, the set of instructions 2700 include operating the system 1000 in the normal operational mode of the system 1000. On a condition in which the controller 1800 receives, at 2704, an indication of a predefined error associated with the normal operational mode of the feature of the surgical instrument, the set of instructions 2700 includes stopping the normal operational mode of the system 1000, at 2706. In some embodiments, the predefined error is a communication error between the feature of the surgical instrument and the controller 1800. In some embodiments, the predefined error is a condition in which a predefined non-zero number of individual samples of a moving window of a set of samples exceed a predefined tolerance. The set of samples can be, for example, samples of a signal associated with the feature of the instrument 1400.

[0091] In addition to stopping the normal operational mode of the system 1000, the system 1000 enters the error tolerant mode, at 2708, but does not enter the fault mode of the system 1000. Concurrent with entry to the error tolerant mode, the controller 1800, at 2710, initiates a timer, the magnitude of which corresponds to an error tolerant mode delay time. The error tolerant mode delay time is a time required to make a predefined number of samples of a signal associated with the feature of the instrument 1400.

[0092] Following entry into the error tolerant mode, the controller 1800 is configured to determine, at 2712, whether an indication of a normal termination of the normal operational mode of the instrument 1400 has been received. The indication of the normal termination can, for example, be an indication that the instrument 1400 has been removed from the system 1000. On a condition that the controller 1800 receives an indication of the normal termination of the normal operational mode before expiration of the error tolerant mode delay time, the normal operational mode of the system 1000 is resumed, at 2702.

[0093] In some embodiments, on a condition in which the controller 1800 does not receive the indication of the normal termination of the normal operational mode before expiration of the error tolerant mode delay time, the controller 1800 is configured to determine, at 2714, whether the retry mode is available for the predefined error mode of the feature of the instrument 1400. As depicted at 2716, on a condition that the retry mode is unavailable, the system 1000 enters the fault mode. However, in embodiments wherein the retry mode is available, the actions executed by the controller 1800 cause the system 1000 to enter the retry mode, at 2718. In the retry mode, the human user of the system 1000 can execute one or more resolution attempts to correct the error associated with the normal operational mode of the feature of the instrument 1400. The resolution attempt can, for example, include an alteration of a condition, orientation, and/or position of the feature of the instrument 1400. As such, the controller 1800 is configured to determine, at 2720 whether an indication of the correction of the error has been received. On a condition in which the system 1000 has entered the retry mode and the controller 1800 has received an indication of the correction of the error associated with the normal operational mode of the feature of the instrument 1400 by the user, the normal operational mode of the surgical system is resumed at 2722. However, on a condition in which the error is not corrected by the user, the fault mode is entered, at 2716.

[0094] In some embodiments, the system 1000 includes a user interface (e.g., an interface of the control unit 1100). In such an embodiment, the instructions 2700 cause the controller 1800 to execute actions that include capturing a steady-state user interface output, which is associated with the feature of the instrument 1400, and which is provided via the user interface to the human user immediately prior to entering the error tolerant mode. Following entry into the error tolerant mode, the controller 1800 can provide the steady-state user interface output to the human user during the error tolerant mode. For example, the steady-state user interface output can be a force output to the human user. The force output to the human user can be associated with the force applied at the distal end of the instrument 1400. By way of additional illustration, in some embodiments, the steady-state user interface output is an image output to the human user. The image output to the human user can be associated with the image at the distal end of the instrument 1400.

[0095] In some embodiments, a normal operational mode of a second feature of the instrument 1400 is defined. In such embodiments, the instructions 2700 include operating the second feature of the instrument 1400 in the normal operational mode of the second feature during the error tolerant mode of the system 1000. Said another way, the normal operational mode of the first feature of the instrument 1400 is stopped in response to the error indication, contemporaneous with the second feature being maintained in the normal operational mode while the system 1000 is in the error tolerant mode. Similarly, in some embodiments, the instructions 2700 include operating the second feature of the instrument 1400 in the normal operational mode of the second feature during the retry mode of the system 1000.

[0096] As shown particularly in FIG. 10, a schematic diagram of one embodiment of suitable components that may be included within the controller 1800 is illustrated. In some embodiments, the controller 1800 is positioned within a component of the system 1000, such as the user control unit 1100 and/or the optional auxiliary equipment unit 1150. However, the controller 1800 may also include distributed computing systems wherein at least one aspect of the controller 1800 is at a location which differs from the remaining components of the system 1000 for example, at least a portion of the controller 1800 may be an online controller.

[0097] As depicted, the controller 1800 includes one or more processor(s) 1802 and associated memory device(s) 1804 configured to perform a variety of computer implemented functions (e.g., performing the methods, steps, calculations and the like and storing relevant data as disclosed herein). Additionally, in some embodiments, the controller 1800 includes a communication module 1806 to facilitate communications between the controller 1800 and the various components of the system 1000.

[0098] As used herein, the term “processor” refers not only to integrated circuits referred to in the art as being included in a computer, but also refers to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits. Additionally, the memory device(s) 1804 may generally comprise memory element(s) including, but not limited to, computer readable medium (e.g., random access memory (RAM)), computer readable nonvolatile medium (e.g., a flash memory), a floppy disc, a compact disc read only memory (CD ROM), a magneto optical disc (MOD), a digital versatile disc (DVD) and/or other suitable memory elements. Such memory device(s) 1804 may generally be configured to store suitable computer readable instructions that, when implemented by the processor(s) 1802, configure the controller 1800 to perform various functions.

[0099] In some embodiments, the controller 1800 includes a haptic feedback module 1820. The haptic feedback module 1820 may be configured to deliver a haptic feedback and/or a force feedback to the operator based on inputs received from a force sensor unit 1850 of the instrument 1400. In some embodiments, haptic feedback module 1820 may be an independent module of the controller 1800. However, in some embodiments the haptic feedback module 1820 may be included within the memory device(s) 1804.

[0100] The communication module 1806 may include a control input module 1808 configured to receive control inputs from the operator/surgeon S, such as via the input device 1116 of the user control unit 1100. The communication module may also include an indicator module 1812 configured to generate various indications in order to alert the operator.

[0101] The communication module 1806 may also include a sensor interface 1810 (e.g., one or more analog to digital converters) to permit signals transmitted from one or more sensors (e.g., strain sensors of the force sensor unit 1850) to be converted into signals that can be understood and processed by the processors 1802. The sensors may be communicatively coupled to the communication module 1806 using any suitable means. For example, the sensors may be coupled to the communication module 1806 via a wired connection and/or via a wireless connection, such as by using any suitable wireless communications protocol known in the art. Additionally, in some embodiments, the communication module 1806 includes a device control module 1814 configured to modify an operating state of the instrument 1400 (and/or any of the instruments described herein. Accordingly, the communication module is communicatively coupled to the manipulator unit 1200 and/or the instrument 1400. For example, the communications module 1806 may communicate to the manipulator unit 1200 and/or the instrument 1400 an excitation voltage for the strain sensor(s), a handshake and/or excitation voltage for a positional sensor (e.g., for detecting the position of the designated portion relative to the cannula), cautery controls, positional setpoints, and/or an end effector operational setpoint (e.g., gripping, cutting, and/or other similar operation performed by the end effector).

[0102] While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Where methods and/or schematics described above indicate certain events and/or flow patterns occurring in certain order, the ordering of certain events and/or operations may be modified. While the embodiments have been particularly shown and described, it will be understood that various changes in form and details may be made. [0103] For example, any of the instruments described herein (and the components therein) are optionally parts of a surgical assembly that performs minimally invasive surgical procedures, and which can include a manipulator unit, a series of kinematic linkages, a set of cannulas, or the like. Thus, any of the instruments described herein can be used in any suitable surgical system, such as the system 1000 shown and described above. Moreover, any of the instruments shown and described herein can be used to manipulate target tissue during a surgical procedure. Such target tissue can be cancer cells, tumor cells, lesions, vascular occlusions, thrombosis, calculi, uterine fibroids, bone metastases, adenomyosis, or any other bodily tissue. The presented examples of target tissue are not an exhaustive list. Moreover, a target structure can also include an artificial substance (or non-tissue) within or associated with a body, such as for example, a stent, a portion of an artificial tube, a fastener within the body or the like.

[0104] Although various embodiments have been described as having particular features and/or combinations of components, other embodiments are possible having a combination of any features and/or components from any of embodiments as discussed above. Aspects have been described in the general context of medical devices, and more specifically surgical instruments, but inventive aspects are not necessarily limited to use in medical devices.

Claims

What is claimed is:

1. A computer-assisted system, comprising: a manipulator unit configured to support an instrument having a sensor unit coupled thereto; an input device operably coupled to the instrument and the manipulator unit; and a controller operably coupled to the manipulator unit, the input device, and the sensor unit, the controller comprising at least one processor, the controller configured to execute a plurality of operations, the plurality of operations comprising: operating a portion of the computer-assisted system in a normal operational mode, receiving a sensor signal from sensor unit corresponding to an operating condition of the instrument, detecting a plurality of instances of a deviation of the sensor signal from a design sensor signal, determining an error rate for the sensor signal based in part on the plurality of instances, on a condition that the error rate greater than or equal to an error rate threshold, entering an error tolerant mode in which operating the portion of the computer-assisted system in the normal operational mode is stopped and initiating a resolution timer, and on a condition that a resolution signal is received prior to an expiration of the resolution timer, resuming the normal operational mode of the computer-assisted system.

2. The computer-assisted system of claim 1, wherein: the plurality of operations includes entering a fault mode on a condition that the resolution signal is not received prior to the expiration of the resolution timer; and at least a partial restart of the computer-assisted system is required to restore the normal operational mode.

3. The computer-assisted system of claim 1, wherein: the plurality of operations includes determining the error rate for the sensor signal by: establishing a rolling sample window that has a specified quantity of sampling intervals, determining a quantity of the sampling intervals that are error intervals, the quantity of error intervals being the quantity of sampling intervals in the rolling sampling window that correspond to an instance of the plurality of instances of the deviation of the sensor signal, and determining the error rate as a ratio of the quantity of error intervals to the quantity of sampling intervals.

4. The computer-assisted system of claim 3, wherein: each sampling interval corresponds to a processor cycle.

5. The computer-assisted system of claim 4, wherein: the processor is configured to have a cycle rate in a range of 1.0 kilohertz to 1.5 kilohertz, and the error rate threshold corresponds to a range of two percent to seven percent of the sampling intervals.

6. The computer-assisted system of claim 3, wherein: the resolution timer has a duration that corresponds to a portion of the sampling intervals of the rolling sample window.

7. The computer-assisted system of claim 1, wherein: the resolution signal is an instrument removal signal.

8. The computer-assisted system of claim 1, wherein: the plurality of operations includes delivering a force feedback to the input device at a magnitude corresponding to a preceding normal sensor signal on a condition that the error rate is less than the error rate threshold and at least one of the plurality of instances of deviation is detected.

9. The computer-assisted system of claim 1, wherein: the plurality of operations includes entering a retry mode from the error tolerant mode on a condition that the resolution signal is not received prior to the expiration of the resolution timer; and the retry mode facilitates an execution of a resolution attempt.

10. The computer-assisted system of claim 9, wherein: entering the retry mode includes establishing a portion of the computer-assisted system in a reduced operational mode; and the reduced operational mode facilitates the resolution attempt by an operator of the computer-assisted system.

11. The computer-assisted system of claim 10, wherein: the reduced operational mode corresponds to an operational mode in which an input to the input device results in an alteration of a condition of at least one of the manipulator unit or the instrument; and a delivery of a force feedback to the input device is precluded in the reduced operational mode.

12. The computer-assisted system of claim 10, wherein: entering the retry mode further includes: initiating a retry timer following the establishment of the portion of the computer- assisted system in the reduced operational mode, and on a condition that the error rate is below the error rate threshold prior to an expiration of the retry timer, resuming the normal operational mode of the computer-assisted system, and on a condition that the error rate is greater than or equal to the error rate threshold upon the expiration of the retry timer, entering a fault mode.

13. The computer-assisted system of claim 12, wherein: the retry timer has a duration of greater than two seconds and less than three seconds following the establishment of the portion of the computer-assisted system in the reduced operational mode.

14. The computer-assisted system of claim 12, wherein: the plurality of operations further includes extending the retry timer on a condition that the error rate has a decreasing trend upon the expiration of the retry timer.

15. The computer-assisted system of claim 9, wherein: the resolution attempt is a first resolution attempt; the retry mode facilitates a second resolution attempt; and the retry mode includes an attempt count limit that corresponds to a maximum number of permitted resolution attempts.

16. The computer-assisted system of claim 15, wherein: the attempt count limit is reset following a specified delay interval.

17. The computer-assisted system of claim 9, wherein: the input device includes a graphical user interface; and the retry mode is implemented in response to an input provided to the controller via the graphical user interface.

18. A computer-assisted system comprising: memory in which instructions are stored, the instructions defining a normal operational mode of a portion of the computer-assisted system in which a human user of the computer- assisted system operates the computer-assisted system to carry out a procedure and a fault mode of the portion of the computer-assisted system in which the human user is required to perform at least a partial restart of the computer-assisted system to reenter the normal operational mode; and one or more controllers operatively coupled to the memory, the instructions causing the one or more controllers to execute actions including: operating the portion of the computer-assisted system in the normal operational mode, on a condition in which the one or more controllers have received an indication of a predefined error, halting the normal operational mode and entering an error tolerant mode of the computer-assisted system in lieu of the fault mode, and on a condition in which the computer-assisted system has entered the error tolerant mode and the one or more controllers have received an indication of a normal termination of the normal operational mode before expiration of an error tolerant mode delay time, resuming the normal operational mode.

19. The computer-assisted system of claim 18, wherein: on a condition in which the computer-assisted system has entered the error tolerant mode, the one or more controllers have not received the indication of the normal termination of the normal operational mode before expiration of the error tolerant mode delay time, and a retry mode is unavailable for the predefined error, the actions include entering the fault mode.

20. The computer-assisted system of claim 18, wherein: on a condition in which the computer-assisted system has entered the error tolerant mode, the one or more controllers have not received the indication of the normal termination of the normal operational mode before expiration of the error tolerant mode delay time, and a retry mode is available for the predefined error, the actions include entering the retry mode.

21. The computer-assisted system of claim 18, wherein: on a condition in which the computer-assisted system has entered a retry mode and the one or more controllers have received an indication of a correction by the human user of the error, the actions include resuming the normal operational mode.

22. The computer-assisted system of claim 18, wherein: on a condition in which the computer-assisted system has entered a retry mode and the one or more controllers have not received an indication of the correction by the human user of the error, the actions include entering the fault mode.

23. The computer-assisted system of claim 18, wherein: the predefined error is a communication error between a feature of an instrument of the computer-assisted system and the one or more controllers.

24. The computer-assisted system of claim 18, wherein: the actions further include providing a moving window of a plurality of samples of a signal associated with a feature of an instrument of the computer-assisted system; and the predefined error is a condition in which a predefined non-zero number of individual samples of the moving window of the plurality of samples exceed a predefined tolerance.

25. The computer-assisted system of claim 18, wherein: the error tolerant mode delay time is a time required to make a predefined number of samples of a signal associated with a feature of an instrument of the computer-assisted system.

26. The computer-assisted system of claim 18, wherein: the indication of the normal termination of the normal operational mode is an indication an instrument has been removed from the computer-assisted system.

27. The computer-assisted system of claim 18, wherein: the predefined error is associated with a force sensor unit positioned to sense a force applied at a distal end of an instrument of the computer-assisted system.

28. The computer-assisted system of claim 18, wherein: the computer-assisted system includes a user interface; and the instructions cause the one or more controllers to execute actions including: capturing a steady-state user interface output, which is associated with a feature of an instrument of the computer-assisted system, and which is provided via the user interface to the human user immediately prior to entering the error tolerant mode, and on the condition the computer-assisted system has entered the error tolerant mode, providing the steady-state user interface output to the human user during the error tolerant mode.

29. The computer-assisted system of claim 28, wherein: the predefined error is associated with a force sensor unit positioned to sense a force applied at a distal end of an instrument of the computer-assisted system; the steady-state user interface output is a force output to the human user; and the force output to the human user is associated with the force applied at the distal end of the instrument.

30. The computer-assisted system of claim 28, wherein: the predefined error is associated with an image sensor positioned to capture an image at a distal end of the instrument; the steady-state user interface output is an image output to the human user; and the image output to the human user is associated with the image at the distal end of the instrument.

31. The computer-assisted system of claim 18, wherein: the normal operational mode is further defined, in which motion of an instrument of the computer-assisted system follows a motion of an input device operated by the human user.

32. The computer-assisted system of claim 18, wherein: the computer-assisted system includes an instrument.

33. The computer-assisted system of claim 18, wherein: the predefined error is associated with a first feature of an instrument of the computer- assisted system; a normal operational mode of a second feature of the instrument is defined; and the instructions cause the one or more controllers to execute actions including: operating the second feature of the instrument in the normal operational mode of the second feature of the instrument during the error tolerant mode of the computer- assisted system.

34. The computer-assisted system of claim 33, wherein: the second feature of the instrument is operated in the normal operational mode of the second feature during a retry mode of the computer-assisted system.