System and method for disengaging clutch operation in a multi-joint arm

Abstract

A computer-assisted medical device is provided. [Solution] A computer-aided medical device includes an articulated arm having one or more first joints, and a control unit coupled to the articulated arm and having one or more processors. The control unit operates each of the first joints in multiple states. The multiple states include a locked state in which movement of each of the first joints is restricted, and a floating state in which movement of each of the first joints is permitted. The control unit is further configured to switch one or more second joints selected from the first joints from the locked state to the floating state when a stimulus to the second joint exceeds one or more unlock thresholds, and to switch the second joints from the floating state to the locked state when the velocity of each of the second joints falls below one or more lock thresholds.

Description

Technical Field

[0001] [Related Applications] This disclosure claims priority to U.S. Provisional Application No. 61 / 954,452, filed on March 17, 2014, entitled "System and Method for Breakaway Clutching in an Articulated Arm"; and U.S. Provisional Patent Application No. 62 / 954,120, filed on June 30, 2014, entitled "CONSTANT FORCE SPRING WITH ACTIVE BIAS", which are hereby incorporated by reference in their entirety.

[0002] This disclosure is generally related to the operation of devices having articulated arms, and more specifically, to breakaway clutching of articulated arms.

Background Art

[0003] An increasing number of devices are being replaced by autonomous and semi-autonomous electronic devices. This is particularly true in today's hospitals that feature large arrays of autonomous and semi-autonomous electronic devices found in operating rooms, interventional suites, intensive care wards, emergency rooms, etc. For example, glass and mercury thermometers have been replaced by electronic thermometers, intravenous drip lines now include electronic monitors and flow regulators, and conventional handheld surgical instruments are being replaced by computer-assisted medical devices.

[0004] These electronic devices present both advantages and challenges to those who operate them. Many of these electronic devices are capable of performing autonomous or semi-autonomous movement of one or more multi-joint arms and / or end effectors. Before these multi-joint arms and their end effectors are used, they are typically moved to or near a desired work position and orientation. This movement can be performed by teleoperation or remote work using one or more user input controls. As the complexity of these electronic devices increases and the multi-joint arms include a large number of degrees of freedom, the movement to a desired work position and orientation by teleoperation becomes complex and / or time-consuming. To streamline this operation, some multi-joint arms include a clutched or float state in which one or more of the brakes of the joints of the multi-joint arm and / or actuators are released, enabling the operator to manually change the position and / or orientation of the multi-joint arm by direct operation. In this way, the multi-joint arm can be quickly and easily positioned and / or oriented as desired. The clutched or float state is often engaged by manually operating one or more clutch control devices on the multi-joint arm and / or by selecting the clutched or float state at the operator console. This type of manual activation can be inconvenient and / or inadvertent.

[0005] Accordingly, an improved method and system for clutching a multi-joint arm are desirable. SUMMARY OF THE INVENTION

[0006] In accordance with some embodiments, a computer-assisted medical device includes a multi-joint arm having one or more first joints and a control unit coupled to the multi-joint arm and having one or more processors. The control unit operates each of the first joints in a number of states. The number of states includes a locked state in which the movement of each first joint is restricted and a floating state in which the movement of each first joint is permitted. The control unit further switches one or more second joints selected from the first joints from the locked state to the floating state when the stimulation to the second joints exceeds one or more unlock thresholds, and switches the second joints from the floating state to the locked state when the respective speed of each second joint is below one or more lock thresholds.

[0007] In accordance with some embodiments, a method of controlling the movement of a medical device includes operating each of one or more first joints of a multi-joint arm of the medical device in one of a number of states. The number of states includes a locked state in which the movement of each joint is restricted and a floating state in which the movement of each joint is permitted. The method further includes determining the stimulation to one or more second joints selected from the joints, switching the second joints from the locked state to the floating state when the stimulation exceeds one or more unlock thresholds, and switching the second joints from the floating state to the locked state when the respective speed of each second joint is lower than one or more lock thresholds.

[0008] In accordance with some embodiments, a non-transitory machine-readable medium includes a plurality of machine-readable instructions adapted to cause one or more processors associated with a medical device to execute a method when executed by the one or more processors. The method includes operating each of one or more first joints of a multi-joint arm of the medical device in one of a number of states. The number of states includes a locked state in which movement of each joint is restricted and a floating state in which movement of each joint is permitted. The method further includes determining a stimulus for one or more second joints selected from the first joints, switching a second joint from the locked state to the floating state when the stimulus exceeds one or more unlock thresholds, and switching a second joint from the floating state to the locked state when a respective speed of the second joint is below one or more lock thresholds.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Best Mode for Carrying Out the Invention

[0010] In the following description, specific details will be set forth that describe several embodiments consistent with the present disclosure. However, it will be apparent to one of ordinary skill in the art that some embodiments may be practiced without some or all of these specific details. The specific embodiments disclosed herein are intended to be illustrative and not limiting. One of ordinary skill in the art will recognize that other elements not specifically described herein are within the scope and spirit of the present disclosure. Also, to avoid unnecessary repetition, one or more features illustrated and described in connection with one embodiment may be incorporated into other embodiments as long as it is not specifically stated otherwise or the one or more features do not render the embodiment non-functional.

[0011] FIG. 1 is a simplified diagram of a computer-assisted system 100 according to some embodiments. As shown in FIG. 1, the computer-assisted system 100 includes an apparatus 110 having one or more movable or articulated arms 120. Each of the one or more articulated arms 120 may support one or more end effectors. In some examples, the apparatus 110 may correspond to a computer-assisted surgical apparatus. Each of the one or more articulated arms 120 provides support for surgical instruments, imaging devices, and the like. The apparatus 110 may further be coupled to an operator workstation (not shown), which may include one or more master controllers for operating the apparatus 110, the one or more articulated arms 120, and / or the end effectors. In some embodiments, the apparatus 110 and the operator workstation may correspond to the da Vinci® Surgical System commercialized by Intuitive Surgical, Inc. of Sunnyvale, California. In some embodiments, other forms of computer-assisted surgical apparatuses having fewer or more articulated arms, etc., may be used with the computer-assisted system 100.

[0012] Device 110 is coupled to control unit 130 via an interface. The interface may include one or more cables, connectors, and / or buses, and may further include one or more networks with one or more network switching and / or routing devices. Control unit 130 includes a processor 140 coupled to a memory 150. The operation of control unit 130 is controlled by processor 140. Control unit 130 is shown as including only one processor 140, but processor 140 may be representative of one or more central processing units, multi-core processors, microprocessors, microcontrollers, digital signal processors, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc. within control unit 130. Control unit 130 may be implemented as a stand-alone subsystem and / or as a board added to a computing device, or as a virtual machine. In some embodiments, the control unit may be included as part of an operator workstation and / or may be separate from but operable in cooperation with an operator workstation.

[0013] Memory 150 may be used to store software executed by control unit 130 and / or one or more data structures used during the operation of control unit 130. Memory 150 may include one or more types of machine-readable media. Some common forms of machine-readable media include floppy disks, flexible disks, hard disks, magnetic tape, any other magnetic medium, CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, RAM, PROM, EPROM, flash EPROM, any other memory chip or cartridge, and / or any other medium adapted to be read by a processor or computer therefrom.

[0014] As shown, memory 150 includes a motion control application 160 that can be used to support autonomous and / or semi-autonomous control of device 110. The motion control application 160 exchanges position, movement, and / or collision avoidance information with other control units regarding other devices for receiving position, movement, and / or other sensor information from device 110, and / or for planning the movement of device 110, multi-joint arm 120, and / or the end effector of device 110, and may include one or more application programming interfaces (APIs). The motion control application 160 is depicted as a software application, but the motion control application 160 may be implemented using hardware, software, and / or a combination of hardware and software.

[0015] In some embodiments, computer-assisted system 100 may be found in an operating room and / or an intervention room. Computer-assisted system 100 includes only one device 110 with two multi-joint arms 120, but one of ordinary skill in the art will understand that computer-assisted system 100 may include any number of devices having multi-joint arms and / or end effectors of the same or different designs as device 110. In some embodiments, each of the devices may include fewer or more multi-joint arms and / or end effectors.

[0016] FIG. 2 is a simplified diagram showing a multi-joint arm 200 according to several embodiments. For example, the multi-joint arm 200 can be a part of one of the multi-joint arms 120 of the apparatus 110. As shown in FIG. 2, the multi-joint arm 200 includes various links and joints. A platform 210 is coupled to the proximal end portion of the multi-joint arm 200. In some examples, the platform 210 can be at the distal end of additional joints and links (not shown) from a computer-assisted device. Coupled to the platform 210 is a series of setup joints and links 220. The setup joints and links 220 are rotatably coupled to the platform 210 via a first setup linkage joint 222. In some examples, additional setup links and joints for other multi-joint arms (not shown) are rotatably coupled to the platform 210 using additional first setup linkage joints. Coupled to the first setup linkage joint 222 is a setup base linkage 224 that is coupled to the proximal end portion of a setup linkage extension link 226 via a first setup linkage linear joint 228. The distal end portion of the setup linkage extension link 226 is coupled to the proximal end portion of a setup linkage vertical link 230 via a second setup linkage linear joint 232. The distal end portion of the setup linkage vertical link 230 is rotatably coupled to the proximal end portion of a support link 234 via a second setup linkage joint 236. A first rotary joint 238 is coupled to the distal end portion of the support link 234. The first rotary joint 238 provides rotational control for additional links and joints located distal to the first rotary joint 238. In some examples, the central axis 250 of the first rotary joint 238 can be aligned with a remote center 290 that can be fixed in place during the teleoperation of the multi-joint arm 200.

[0017] The coupling link 240 couples the first rotational joint 238 to the second rotational joint 242. The second rotational joint 240 is coupled to the yaw joint 252 via the yaw link 254. Coupled distally to the yaw joint 252 is a parallelogram pitch mechanism 260. At the proximal end of the parallelogram pitch mechanism 260 is a first pitch link 262 that couples the yaw joint 252 to the first pitch joint 264. A second pitch link 266 couples the first pitch joint 264 to the second pitch joint 268. A third pitch link 270 couples the second pitch joint 268 to the third pitch joint 272. The instrument cartridge is coupled to the third pitch joint 272 and includes an instrument shaft 280. One or more end effectors may be coupled to the distal end of the instrument shaft 280. In some examples, the parallel pitch mechanism 260 may be controlled to align and maintain the instrument shaft 280 with the remote center 290.

[0018] As shown in FIG. 2, the articulated arm 200 includes a number of linkages 224, 226, 230, 234, 240, 254, 262, 266, 270, and 280, the relative positions and / or orientations of which may be adjusted using a number of linear joints 228 and 232 and a number of rotational joints 222, 236, 238, 242, 262, 264, 268, and 272. Each of the linear and rotational joints may include one or more sensors for sensing, among other things, the position, rotation, movement, force, and / or torque of the respective joint.

[0019] Depending on the desired capabilities for controlling the multi-joint arm 200, each of the various joints can be a non-operating or an operating joint. In some examples, a non-operating joint may not include any actuators and thus cannot be operated by remote control and / or operating control instructions from the control unit of the multi-joint arm 200. In some examples, a non-operating joint may include a brake that enables the control unit to prevent and / or limit movement at the non-operating joint. In some examples, joints 228, 232, and / or 236 of FIG. 2 can be non-operating joints. In some examples, an operating joint may include one or more actuators that can control the movement of the operating joint by remote control and / or operating instructions. In some examples, an operating joint may further include a brake.

[0020] In some embodiments, to prevent unwanted movement, various joints and links of the multi-joint arm 200 can be placed in a locked state where each of the non-operating joint brakes is actuated and each of the operating joint actuators is commanded to hold the operating joint at the commanded position. In some examples, the locked state additionally prevents unwanted movement due to gravity acting on the multi-joint arm 200. Although not shown in FIG. 2, the multi-joint arm 200 can include one or more clutch buttons or controls. In some examples, the clutch buttons can be located at various locations along the instrument cartridge. In some examples, an additional clutch control device can be actuated by operator control at the operator console. By actuating one or more of the clutch buttons or controls, one or more joints of the multi-joint arm can be switched from the locked state to a clutch-operated state or floating state where at least some of the non-operating joint brakes are at least partially released and at least some of the operating joint actuators are allowed to move the joints away from the commanded position. For example, actuation of a clutch button disposed on the multi-joint arm 200 can place the multi-joint arm 200 in a floating state while the other parts of the computer-assisted device coupled to the platform 210 remain in the locked state. While the multi-joint arm 200 is in the floating state, the operator can manually position and / or orient the multi-joint arm 200 to a desired working position and orientation.

[0021] In some embodiments, manual activation of the clutch operating mechanism of the multi-joint arm 200 may not necessarily be practical and / or well thought out. In some examples, the location of the clutch button or control device may not be convenient for easy activation by the operator. In some examples, the operator may not have a free finger and / or hand to operate the clutch control device. In some examples, coordination of clutch control with other operators located at the operator console may not be possible and / or practical. In some examples, the operator may not be able to operate the clutch control device without breaking the sterile field established around a portion of the multi-joint arm 200. Therefore, it is advantageous to put at least a portion of the multi-joint arm 200 into a floating state without activation of clutch control by the operator.

[0022] In some embodiments, the movement of the multi-joint arm 200 may be desired without manual clutch activation. In some examples, an unintentional collision may occur between the operator, patient, and / or object and one or more links and / or joints of the multi-joint arm 200. In some examples, these unintentional collisions can result in injury to the operator, injury to the patient, damage to the object, and / or damage to the multi-joint arm 200 due to the fixed position and / or orientation maintained by the multi-joint arm 200. In some examples, being able to detect an unintentional collision and automatically put the multi-joint arm 200 into a floating state can reduce injury to the operator, injury to the patient, damage to the object, and / or damage to the multi-joint arm 200.

[0023] FIG. 3 is a simplified diagram of a method 300 for releasing clutch operation according to some embodiments. One or more of processes 310-360 of method 300 can be implemented, at least in part, in the form of executable code stored on a non-transitory, tangible, machine-readable medium, which, when executed by one or more processors (e.g., processor 140 of control unit 130), causes the one or more processors to execute one or more of processes 310-360. In some embodiments, method 300 can be executed by an application, such as motion control application 160.

[0024] In process 310, enter the locked state. Joints of a multi-joint arm, such as multi-joint arms 120 and / or 200, can be placed in the locked state by default. In the locked state, movement of the multi-joint arm can be prevented and / or reduced by activating a brake at each of the non-operating joints of the multi-joint arm and by holding each of the operating joints of the multi-joint arm at their respective commanded positions using the corresponding operating joint actuators.

[0025] In process 320, an external stimulus to one or more joints is determined. One or more sensors associated with each joint of the multi-joint arm are periodically read and / or monitored to determine whether an external stimulus is being applied to one or more joints of the multi-joint arm. In some examples, a linear sensor associated with a linear joint and / or a rotational sensor associated with a rotational joint are monitored to determine the actual position of each joint. In some examples, a position error can be determined based on the difference between the actual position and the commanded position in an actuated joint and / or the brake position in a non-actuated joint. In some examples, the position error can be transformed to estimate the force and / or torque to each joint by using one or more kinematic models, inverse Jacobian matrix transformation, and / or a control model for each joint. In some examples, the force and / or torque to each joint can be measured using force and / or torque sensors that monitor each joint. In some examples, the joint velocity of an actuated joint can also be numerically determined using one or more velocity sensors associated with the actuated joint or based on the change in the actual position of the actuated joint.

[0026] In process 330, it is determined whether an external stimulus to any of the joints exceeds the unlock threshold. Each external stimulus value of the joints determined during process 320 is compared to one or more unlock thresholds to ascertain whether any of the unlock thresholds are exceeded. In some examples, a joint of the multi-joint arm can be switched to a floating state using process 340 when any one of the external joint stimulus values exceeds its respective unlock threshold. In some examples, a joint of the multi-joint arm can be switched to a floating state when two or more combinations of the external joint stimulus values exceed their respective unlock thresholds. In some examples, a joint of the multi-joint arm can be switched to a floating state when a weighted and / or un-weighted aggregation of external stimulus values from two or more joints exceeds a composite unlock threshold. In some examples, the aggregation can include an average, median, sum of squares, minimum, and / or maximum, etc.

[0027] In some examples, each unlock threshold for each joint may vary depending on the location and / or purpose of each joint of the multi-joint arm. In some examples, the unlock threshold may be adjusted based on the current pose, position, and / or orientation of the multi-joint arm. In some examples, each unlock threshold for each joint may be adjusted and / or disabled when each joint exceeds a soft stop near an end of the possible movement for each joint. In some examples, the floating state may be initiated by default when each joint exceeds the soft stop. In some examples, the determination of whether an external stimulus exceeds a threshold may be limited to a subset of the joints of the multi-joint arm. In some examples, external stimuli to non-operating joints that are braked may not be monitored during process 320 and may not have corresponding unlock thresholds. In some examples, the unlock threshold may be adjusted based on the size and / or mass of the multi-joint arm. In some examples, the unlock threshold may be large enough to avoid an unexpected switch to the floating state due to gravity and / or errors in the joint sensors.

[0028] In some examples, the unlock threshold may correspond to a threshold value related to the position error between the actual position of the joint and the command and / or brake position of the joint. In some examples, the threshold value may be between 0.02 and 5 millimeters for a linear joint. In some examples, the threshold value may be between 0.03 and 0.5 degrees for a rotary joint. In some examples, one or more unlock thresholds may correspond to the force and / or torque applied to the joint as measured and / or determined during process 320. In some examples, the threshold value may be from 1 to 30 N for a force applied to a linear joint. In some examples, the threshold value may be between 1 and 30 Nm for a torque applied to a rotary joint. In some examples, the threshold value may exceed the force and / or torque saturation value for the joint.

[0029] In some embodiments, the unlocking threshold should be exceeded for a predetermined period before switching the multi-joint arm to the floating state. In some examples, the joints of the multi-joint arm can be switched to the floating state when each external stimulus value continuously exceeds the unlocking threshold corresponding thereto for a predetermined period. In some examples, the joints of the multi-joint arm can be switched to the floating state when the aggregation of each external stimulus value over a predetermined period, such as an average, etc., exceeds each stimulus value. In some examples, a sliding window and / or exponential smoothing method can be used to determine the aggregation. In some examples, a filter is used for the detected external stimulus that emphasizes intermediate frequencies to better separate disturbances caused by human intention from disturbances caused by gravity and other environmental factors that can be of low frequency. In some examples, the intermediate frequency can range from approximately 0.01 Hz to 10 Hz. In some examples, discrete wavelet transform can be used instead of or in combination with a filter to better separate disturbances caused by human intention. In some examples, the predetermined period can be set by an operator. In some examples, the predetermined period can be between 50 and 150 milliseconds. In some examples, the predetermined period can be different when the separation clutch operation is first activated to avoid an unexpected switch to the floating state due to static disturbances from the environment that are confused with the remaining momentum of the multi-joint arm and / or user input caused by other recently completed operations. In some examples, to avoid an unexpected switch to the floating state due to likely temporary situations such as the multi-joint arm being detached from the patient and / or the end effector being attached to or removed from the multi-joint arm, a state where the external stimulus is below the unlocking threshold for a predetermined period should be established before the separation clutch operation is first activated. In some examples, the predetermined time can range between an additional 100 and 250 milliseconds after the separation clutch operation is enabled.

[0030] When the external stimulus does not exceed one or more unlock thresholds, the external stimulus is determined using process 320 again. When the external stimulus exceeds one or more unlock thresholds, the joints of the multi-joint arm are switched to a floating state using process 340.

[0031] In process 340, enter the floating state. One or more of the joints of the multi-joint arm are placed in a floating state that allows free and / or substantially free movement of the joints. In some examples, the joints placed in the floating state can be a subset of the joints of the multi-joint arm. In some examples, this allows applying a disengaging clutch operation to these parts of the multi-joint arm that are the target of the external stimulus. In some examples, the brakes of each of the non-operating joints placed in the floating state can be released to enable the movement of each of the non-operating joints. In some examples, each of the operating joints placed in the floating state can be commanded to move to the actual position determined during process 320 or while the operating joint remains in the floating state. In some examples, each of the operating joints placed in the floating state can also be commanded to conform to the joint speed determined during process 320 or while the operating joint remains in the floating state. In some examples, setting the commanded position of the feedback controller of the operating joint to the actual position and / or the commanded speed of the feedback controller to the actual joint speed gives the impression that the operating joint is moving freely and, when gravity compensation is also applied, the impression of apparent weightlessness.

[0032] In some embodiments, the movement of the joint in the floating state can be subject to damping. To reduce and / or prevent unrestricted and / or thrashing movement of the multi-joint arm during the floating state, one or more of the joints placed in the floating state can be subject to some form of damped movement. For example, a multi-joint arm that is subject to strong external stimuli such as a violent collision may not desire to move away from the strong external stimuli without any constraints. Restraining the clutch-operated movement can reduce the risk of injury and / or damage caused by the fast-moving multi-joint arm. In some examples, the damped movement can be implemented on the non-actuated arm by partially releasing the brake so as to set a resistance to the movement of the non-actuated joint. In some examples, the brake can be partially released by controlling one or more of the voltage, current, and / or duty cycle of the signal used to control the brake. In some examples, the damped movement can be implemented on the actuated joint by instructing the actuated joint to move a portion of the distance behind the actual position based on the direction of movement, increasing the derivative constant of the feedback controller without significantly affecting the stability margin of the feedback controller, and / or introducing reverse current and / or voltage to the actuator of the actuated joint so as to mimic the resistance force and / or torque. In some examples, the damped movement can be implemented on the actuated joint by instructing the speed of the actuated joint to a value below the joint speed determined during process 320 or while the actuated joint remains in the floating state. In some examples, the damped movement can be adjusted to take into account the current posture, position, and / or orientation of the multi-joint arm, and / or the size and / or mass of the multi-joint arm, etc.

[0033] In some embodiments, one or more of the joints of the multi-joint arm that are not in a floating state may be subject to compliant motion restriction. In some examples, joints that are not in a floating state may be commanded in response to the detected motion of joints that are in a floating state. In some examples, joints that are not in a floating state may be commanded to one or more positions and / or orientations. In the example of FIG. 2, one or more of the joints of the parallelogram pitch mechanism 260 may be commanded to maintain the intersection with the central axis 250 of the instrument shaft 280 at the remote center 290.

[0034] In process 350, joint velocities are determined. One or more sensors associated with each joint of the multi-joint arm are periodically read and / or monitored to determine the respective velocity of each joint that is in a floating state. In some examples, changes in linear and / or rotational position between two consecutive monitoring intervals are used to estimate the joint velocity. In some examples, numerical and / or other differential techniques may be used to determine the joint velocity from the detected position. In some examples, the velocity sensors of the joints may be monitored.

[0035] In process 360, it is determined whether the joint speed has dropped below the lock threshold. During the disengaging clutch operation, the joints of the multi-joint arm are kept floating as long as continuous movement of the multi-joint arm is detected. The joint speed determined during process 350 is compared with one or more lock thresholds to ascertain whether continuous movement is being detected in the multi-joint arm. In some examples, each of the joint speeds can be compared with a corresponding lock threshold. When each of the joint speeds is less than its corresponding lock threshold, a lack of movement is detected and the joints of the multi-joint arm are switched to the locked state using process 310. In some examples, the joints of the multi-joint arm can be switched to the locked state using process 310 when the weighted and / or unweighted aggregation of the joint speeds from each of the joints is less than a combined lock threshold. In some examples, the aggregation can include an average, median, sum of squares, minimum, and / or maximum, etc.

[0036] In some examples, each of the lock thresholds for each joint can vary depending on the location and / or purpose of each joint of the multi-joint arm. In some examples, the lock threshold can be adjusted based on the current posture, position, and / or orientation of the multi-joint arm. In some examples, the lock threshold for each joint can be adjusted and / or disabled when each joint has crossed a soft stop near the end of the possible movement for each joint. In some examples, the locked state can be initiated by default when each joint has crossed a soft stop. In some examples, the determination of whether the joint speed is less than the lock threshold can be limited to a subset of the joints of the multi-joint arm. In some examples, the lock threshold can be adjusted based on the size and / or mass of the multi-joint arm. In some examples, the lock threshold can be made large enough to avoid an unexpected switch to locked due to an error in the joint sensor.

[0037] In some examples, the lock threshold can be between 0.1 and 10 millimeters per second for a linear joint. In some examples, the value of the threshold can be between 0.25 and 10 degrees per second for a rotational joint.

[0038] In some embodiments, the joint speed should remain below the lock threshold for a predetermined period before switching the joint of the multi-joint arm to the locked state. In some examples, the joint of the multi-joint arm can be switched to the locked state when the joint speed is continuously below the corresponding lock threshold for a predetermined period. In some examples, the joint of the multi-joint arm can be switched to the locked state when the aggregation, such as the average, of each joint speed over a predetermined period is below the respective lock threshold. In some examples, a sliding window and / or exponential smoothing can be used to determine the aggregation. In some examples, the predetermined period can be set by an operator. In some examples, the predetermined period can be between 100 and 200 milliseconds.

[0039] When the joint speed remains above the lock threshold, the joint speed is determined again using process 350. When the joint speed is below the lock threshold, the joint of the multi-joint arm is switched to the locked state using process 310.

[0040] As discussed above and further emphasized herein, FIG. 3 is merely an example and should not unduly limit the scope of the claims. One of ordinary skill in the art will recognize many variations, alternatives, and modifications. According to some embodiments, the disengaging clutch operation of method 300 may be disabled during certain operating modes of the multi-joint arm. In some examples, the disengaging clutch operation may be disabled when the multi-joint arm is in a firmly locked state during storage and / or when the cart to which the multi-joint arm is attached is being transported between locations. In some examples, the disengaging clutch operation may be disabled when the multi-joint arm is in an operating remote operation mode and / or when performing a commanded movement, such as when docked to a patient. In some examples, disabling the disengaging clutch operation during an operating operation may reduce the likelihood that manual interference and / or collisions with the operating arm will interfere with the remote operation and / or commanded movement, and thus may reduce the further likelihood of damaging the object being operated on and / or injuring the patient on whom the operating arm is being used. In some examples, the disengaging clutch operation may be adjusted, forced, or disabled when any of the joints of the multi-joint arm exceeds a soft stop position.

[0041] Some examples of a control unit, such as control unit 130, may include a non-transitory, tangible, machine-readable medium that includes executable code that, when executed by one or more processors (e.g., processor 140), may cause the one or more processors to execute the processes of method 300. Some common forms of machine-readable media that may include the processes of method 300 are, for example, floppy disks, flexible disks, hard disks, magnetic tapes, any other magnetic medium, CD-ROMs, any other optical medium, punch cards, paper tapes, any other physical medium with patterns of holes, RAM, PROM, EPROM, flash EPROM, any other memory chip or cartridge, and / or any other medium adapted to be read by a processor or computer therefrom.

[0042] While exemplary embodiments have been described and shown, a wide range of modifications, changes, and substitutions are contemplated in the foregoing description, and in some instances, some features of the embodiments may be used without the corresponding use of other features. Those skilled in the art will recognize many variations, alternatives, and modifications. Accordingly, the scope of the present invention should be limited only by the following claims, and the claims should be construed broadly and in a manner consistent with the scope of the embodiments disclosed herein.

[0043] Note the following supplementary remarks. (Supplementary Note 1) A multi-joint arm having one or more first joints; and A control unit coupled to the multi-joint arm and having one or more processors; having, The control unit: Each of the first joints, A locked state in which the movement of each of the first joints is restricted; and, An operating state including a floating state in which the movement of each of the first joints is permitted, One or more second joints selected from the first joints are switched from the locked state to the floating state when the stimulation to the second joints exceeds one or more unlocking thresholds, The second joints are switched from the floating state to the locked state when the respective speeds of the second joints are below one or more locking thresholds, A computer-assisted medical device. (Supplementary Note 2) The control unit switches the second joints from the locked state to the floating state based on the activation of one or more clutch control devices, The device according to Supplementary Note 1. (Supplementary Note 3) The control unit determines the stimulation based on readings from one or more sensors associated with each of the second joints, The device according to Supplementary Note 1. (Supplementary Note 4) The control unit determines the speed of each of the second joints based on reading values from one or more sensors associated with each of the second joints. The device according to Supplementary Note 1. (Supplementary Note 5) Each of the unlocking thresholds is associated with one of each of the second joints. The device according to Supplementary Note 1. (Supplementary Note 6) Each of the unlocking thresholds is determined based on one of each of the second joints with which they are associated. The device according to Supplementary Note 5. (Supplementary Note 7) The unlocking threshold is changed based on the current posture, position, or orientation of the multi-joint arm. The device according to Supplementary Note 1. (Supplementary Note 8) The control unit switches the second joint from the locked state to the floating state when the collective stimulus for the second joint exceeds the synthetic unlocking threshold. The device according to Supplementary Note 1. (Supplementary Note 9) The control unit switches the second joint from the locked state to the floating state when each stimulus for a third joint among the second joints exceeds the respective unlocking threshold for the third joint. The device according to Supplementary Note 1. (Supplementary Note 10) When the third joint is an active joint, each of the stimuli for the third joint corresponds to the position error between the commanded position of the third joint and the current position of the third joint. The device according to Supplementary Note 9. (Supplementary Note 11) When the third joint is an inactive joint, each of the stimuli for the third joint corresponds to the position error between the brake position of the third joint and the current position of the third joint. The device according to Supplementary Note 9. (Appendix 12) Each of the stimuli for the third joint corresponds to a force or torque on the third joint, The device according to Appendix 9. (Appendix 13) The force or torque on the third joint is read from one or more sensors that monitor the third joint, The device according to Appendix 12. (Appendix 14) The force or torque on the third joint is inferred from the position error of the third joint, The device according to Appendix 12. (Appendix 15) When the stimulus for the third joint continuously exceeds each of the unlocking thresholds for a predetermined period, the control unit switches the second joint from the locked state to the floating state, The device according to Appendix 9. (Appendix 16) The predetermined period is longer than when the third joint is first switched to the floating state, The device according to Appendix 15. (Appendix 17) When the sum of the stimuli for the third joint over a predetermined period exceeds each of the unlocking thresholds, the control unit switches the second joint from the locked state to the floating state, The device according to Appendix 9. (Appendix 18) Each of the unlocking thresholds is large enough to prevent the third joint from switching to the floating state due to sensor error or gravitational stimulus, The device according to Appendix 9. (Appendix 19) Each of the unlocking thresholds is associated with each one of the second joints, The device according to Appendix 1. (Appendix 20) Each of the unlocking thresholds is determined based on each one of the second joints with which they are associated, The device according to Appendix 19. (Supplementary Note 21) The unlocking threshold value can be changed based on the current posture, position, or orientation of the multi-joint arm. The device according to Supplementary Note 1. (Supplementary Note 22) When the combined speed of the second joints is lower than the combined locking threshold value, the control unit switches the second joints from the floating state to the locked state. The device according to Supplementary Note 1. (Supplementary Note 23) When the speed of each of the second joints is lower than the respective locking threshold value for each of the second joints, the control unit switches the second joints from the floating state to the locked state. The device according to Supplementary Note 1. (Supplementary Note 24) Each of the speeds of the second joints corresponds to a change in the position of each of the second joints over a predetermined period. The device according to Supplementary Note 23. (Supplementary Note 25) When the speed of each of the second joints continuously falls below the respective locking threshold value for a predetermined period, the control unit switches the second joints from the floating state to the locked state. The device according to Supplementary Note 23. (Supplementary Note 26) When the sum of the speeds of each of the second joints over a predetermined period is lower than the respective locking threshold value, the control unit switches the second joints from the floating state to the locked state. The device according to Supplementary Note 23. (Supplementary Note 27) Each of the locking threshold values is large enough to prevent the second joints from being switched to the locked state due to sensor errors. The device according to Supplementary Note 23. (Supplementary Note 28) The unlocking threshold value is based on whether any of the second joints has exceeded its respective soft stop position. The device according to Supplementary Note 1. (Supplementary Note 29) The locking threshold value is based on whether any of the second joints has exceeded its respective soft stop position. The device according to Supplementary Note 1. (Supplementary Note 30) When the one or more second joints are in the locked state, the control unit activates one or more brakes for the one or more second joints that are non-operating joints. The device according to Supplementary Note 1. (Supplementary Note 31) When the second joint is in the locked state, the control unit holds the second joint, which is an operating joint, at its respective commanded position. The device according to Supplementary Note 1. (Supplementary Note 32) When the second joint is in the floating state, the control unit releases one or more brakes for the second joint that is a non-operating joint. The device according to Supplementary Note 1. (Supplementary Note 33) When the second joint is in the floating state, the control unit partially releases one or more brakes for the second joint that is a non-operating joint. The device according to Supplementary Note 1. (Supplementary Note 34) When the second joint is in the floating state, the control unit commands the second joint, which is an operating joint, to its respective actual position. The device according to Supplementary Note 1. (Supplementary Note 35) When the second joint is in the floating state, the control unit commands the second joint, which is an operating joint, to its respective actual speed. The device according to Supplementary Note 34. (Supplementary Note 36) When the second joint is in the floating state, the control unit introduces respective resistance or torque to the second joint, which is an operating joint. The device according to Supplementary Note 1. (Supplementary Note 37) When the second joint is in the floating state, the control unit commands the second joint, which is an operating joint, to the respective position between its respective actual position and its respective commanded position. The device according to Supplementary Note 1. (Appendix 38) When the second joint is in the floating state, the control unit commands the second joint, which is the operating joint, to have respective speeds lower than their respective actual speeds. The device according to Appendix 1. (Appendix 39) When the multi-joint arm is in a predetermined operation mode, the control unit prevents the second joint from switching to the floating state. The device according to Appendix 1. (Appendix 40) The predetermined operation mode corresponds to one or more modes or conditions selected from the group consisting of a transport mode, a remote operation mode, a commanded motion mode, a patient attachment mode, and the condition that the stimulation to the second joint does not exceed the unlocking threshold value. The device according to Appendix 39. (Appendix 41) When any of the second joints exceeds its respective soft stop position, the control unit switches the second joint from the locked state to the floating state. The device according to Appendix 1. (Appendix 42) When any of the second joints exceeds its respective soft stop position, the control unit switches the second joint from the floating state to the locked state. The device according to Appendix 1. (Appendix 43) The control unit applies the stimulation to a filter. The device according to Appendix 1. (Appendix 44) The control unit applies discrete wavelet transform to the stimulation. The device according to Appendix 1. (Appendix 45) Before the second joint is first switched to the floating state, the control unit holds the second joint in the locked state for a predetermined period. The device according to Appendix 1. (Supplementary Note 46) Before enabling the first switching of the second joint to the floating state, the control unit holds the second joint in the locked state until the stimulation to the third joint falls below the respective unlocking threshold values for a predetermined period. The device according to Supplementary Note 1. (Supplementary Note 47) A method for controlling the movement of a medical device, comprising: operating each of one or more first joints of a multi-joint arm of the medical device in one of a number of states, the number of states including: a locked state in which the movement of each respective joint is restricted; and a floating state in which the movement of each respective joint is permitted; determining a stimulation to one or more second joints selected from the joints; switching the second joint from the locked state to the floating state when the stimulation exceeds one or more unlocking threshold values; determining the respective speed of each of the second joints; and switching the second joint from the floating state to the locked state when the respective speed of each of the second joints is below one or more locking threshold values. Method. (Supplementary Note 48) The step of determining the stimulation includes reading one or more sensors associated with each of the second joints. The method according to Supplementary Note 47. (Supplementary Note 49) The method further includes determining the respective speed of each of the second joints based on readings from one or more sensors associated with each of the second joints. The method according to Supplementary Note 47. (Supplementary Note 50) The unlocking threshold value is respectively associated with each one of the second joints. The method according to Supplementary Note 47. (Appendix 51) further comprising the step of changing the unlocking threshold value based on the current posture, position, or orientation of the multi-joint arm. The method according to Appendix 47. (Appendix 52) further comprising the step of switching the second joint from the locked state to the floating state when each stimulus to the third joint among the second joints exceeds each unlocking threshold value for the third joint. The method according to Appendix 47. (Appendix 53) The unlocking threshold value is respectively associated with each one of the second joints. The method according to Appendix 47. (Appendix 54) further comprising the step of changing the locking threshold value based on the current posture, position, or orientation of the multi-joint arm. The method according to Appendix 47. (Appendix 55) further comprising the step of switching the second joint from the floating state to the locked state when each of the speeds of the second joints continuously falls below each locking threshold value for a predetermined period. The method according to Appendix 47. (Appendix 56) further comprising the step of releasing one or more brakes for the second joint, which is a non-operating joint, when the second joint is in the floating state. The method according to Appendix 47. (Appendix 57) further comprising the step of commanding each actual position to the second joint, which is an operating joint, when the second joint is in the floating state. The method according to Appendix 47. (Appendix 58) further comprising the step of preventing the switching of the second joint to the floating state when the multi-joint arm is in a predetermined operating mode corresponding to one or more modes or conditions selected from the group consisting of a transport mode, a remote operation mode, a commanded operation mode, a patient attachment mode, and a condition where the stimulus to the second joint does not exceed the unlocking threshold value. The method according to Appendix 47. (Supplementary Note 59) further including the step of switching the second joint from the locked state to the floating state when the third joint among the second joints exceeds its respective soft stop position The method according to Supplementary Note 47 (Supplementary Note 60) further including the step of switching the second joint from the floating state to the locked state when the third joint among the second joints exceeds its respective soft stop position The method according to Supplementary Note 47 (Supplementary Note 61) further including the step of applying the stimulus to a filter The method according to Supplementary Note 47 (Supplementary Note 62) further including the step of maintaining the second joint in the locked state until the stimulus to the third joint falls below its respective unlock threshold for a predetermined period before enabling the first switch of the second joint to the floating state The method according to Supplementary Note 47 (Supplementary Note 63) A non - transitory machine - readable medium including a plurality of machine - readable instructions adapted to cause one or more processors to execute a method when executed by the one or more processors associated with a medical device, the method comprising: operating each of one or more first joints of a multi - joint arm of the medical device in one of a number of states, the number of states including: a locked state in which the movement of each joint is restricted, and a floating state in which the movement of each joint is permitted; determining a stimulus to one or more second joints selected from the first joints; switching the second joint from the locked state to the floating state when the stimulus exceeds one or more unlock thresholds; determining the respective speed of the second joint; and When each of the speeds of the second joints is below one or more lock thresholds, switching the second joints from the floating state to the locked state; including medium

Claims

1. A multi-joint arm having a plurality of joints; and A control unit coupled to the multi-joint arm and having one or more processors; having, The control unit: When the multi-joint arm is in a predetermined operation mode, prevent switching of a single first joint among the plurality of joints from a locked state to a floating state, When an external stimulus applied to the single first joint exceeds a first unlocking threshold and the multi-joint arm is not in the predetermined operation mode, switch the single first joint from the locked state to the floating state, When the speed of the single first joint is below a first locking threshold, switch the single first joint from the floating state to the locked state, When the single first joint is a non-operating joint in the locked state, the single first joint is prevented from moving by actuation of a brake, When the single first joint is an operating joint in the locked state, the single first joint is prevented from moving from the commanded position by holding the single first joint at the commanded position, When the single first joint is in the floating state, the single first joint is allowed to move so that an operator can manually position, manually orient, or both manually position and manually orient the multi-joint arm. A computer-assisted medical device.

2. The predetermined operation mode includes a mode selected from the group consisting of a transport mode, a remote operation mode, a commanded motion mode, and a patient attachment mode. The computer-assisted medical device according to claim 1.

3. The single first joint is an operating joint, and the control unit: While the single first joint is in the floating state, commanding the actual position of the single first joint to the single first joint; or While the single first joint is in the floating state, commanding the actual speed of the single first joint to the single first joint configured as The computer-assisted medical device according to claim 1.

4. The single first joint is a non-operating joint, and the control unit further: configured to at least partially release the brake while the single first joint is in the floating state The computer-assisted medical device according to claim 1.

5. The first unlocking threshold is adjusted based on the posture, position, or orientation of the multi-joint arm; or The first locking threshold is adjusted based on the posture, the position, or the orientation of the multi-joint arm The computer-assisted medical device according to claim 1.

6. The control unit further: When the external stimulus applied to the single first joint continuously exceeds the first unlocking threshold for a predetermined period, switching the single first joint from the locked state to the floating state configured as The computer-assisted medical device according to any one of claims 1 to 5.

7. The control unit further: When the external stimulus applied to a single second joint among the plurality of joints exceeds a second unlocking threshold, switching the single first joint from the locked state to the floating state; or When the weighted or unweighted sum of the external stimuli applied to the single first joint and the external stimuli applied to the single second joint exceeds a combined unlocking threshold, the single first joint is switched from the locked state to the floating state. configured as The computer-assisted medical device according to any one of claims 1 to 5.

8. The control unit further: configured to switch the single first joint from the floating state to the locked state when the speed of the single first joint continuously falls below the first locking threshold for a predetermined period. The computer-assisted medical device according to any one of claims 1 to 5.

9. To determine the external stimulus, the control unit: determines a position error of the single first joint between the commanded position of the single first joint and the current position of the single first joint, wherein the single first joint is an active joint. configured to The computer-assisted medical device according to any one of claims 1 to 5.

10. To determine the external stimulus, the control unit: determines a position error between the brake position of the single first joint and the current position of the single first joint, wherein the single first joint is a non-active joint. configured to The computer-assisted medical device according to any one of claims 1 to 5.

11. To determine the external stimulus, the control unit: a force or torque on the single first joint configured to determine The computer-aided medical device according to any one of claims 1 to 5.

12. A method of operating a medical device having a multi-joint arm and a control unit coupled to the multi-joint arm, the method comprising: When the multi-joint arm is in a predetermined operation mode, preventing the control unit from switching the joints of the multi-joint arm from a locked state to a floating state; When an external stimulus applied to the joint exceeds an unlocking threshold and the multi-joint arm is not in the predetermined operation mode, switching the joint from the locked state to the floating state by the control unit; When the speed of the joint is below a first locking threshold, switching the joint from the floating state to the locked state by the control unit; When the joint is a non-operating joint in the locked state, the joint is prevented from moving by the operation of a brake, When the joint is an operating joint in the locked state, the joint is prevented from moving from the commanded position by holding the joint at the commanded position, When the joint is in the floating state, the joint is allowed to move so that an operator can manually position, manually orient, or both manually position and manually orient the multi-joint arm. Operating method.

13. The predetermined operation mode includes a mode selected from the group consisting of a transport mode, a remote operation mode, a commanded operation mode, and a patient attachment mode. The operating method according to claim 12.

14. The joint is an operating joint, and the method further includes: While the joint is in the floating state, the control unit commands the joint with the actual position of the joint; or While the joint is in the floating state, the control unit commands the joint with the actual speed of the joint; comprising The operating method according to claim 12.

15. The operating method further comprises: While the joint is in the floating state, the control unit at least partially releases the brake; The operating method according to claim 12.

16. Determining the external stimulus is: A position error between the commanded position of the joint and the current position of the joint, wherein the joint is an operating joint including determining The operating method according to claim 12.

17. Determining the external stimulus is: A position error between the brake position of the joint and the current position of the joint, wherein the joint is a non-operating joint including determining The operating method according to claim 12.

18. Determining the external stimulus is: A force or torque on the joint including determining The operating method according to claim 12.

19. A non-transitory machine-readable medium including a plurality of machine-readable instructions adapted to cause one or more processors associated with a medical device to execute the operating method according to any one of claims 12 to 18 when executed by the one or more processors.

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