How to Dynamically Stop a Motor

Abstract

The medical system may include a motor of a robotic component, a driver circuit coupled to the motor, and a shunt circuit coupled to the driver circuit. The shunt circuit may be configured to shunt the driver circuit for a set amount of time to stop the motor. The shunt circuit may include a capacitor (C) and a first resistor (R), where the capacitor and the first resistor have an RC time constant, and the amount of set time corresponds to the RC time constant. Methods for operating the shunt circuit are also disclosed herein.

Description

[Technical field]

[0001] The systems and methods disclosed herein are directed to dynamically stopping a motor, and more particularly, to using shunting techniques to dynamically stop a motor. [Background technology]

[0002] Robot-enabled medical systems can perform a variety of medical procedures, including both minimally invasive procedures such as laparoscopy, and non-invasive procedures such as endoscopy (e.g., bronchoscopy, ureteroscopy, gastroscopy, etc.). Such robotic medical systems may include one or more robotic arms configured to control the movement of a medical tool(s) during a given medical procedure. Each robotic arm may include one or more motors for driving its joints. In an emergency shutdown scenario, the motor(s) need to be shut off quickly and safely. In some situations, the motor(s) may be back-drivable after shutting off, allowing an operator to manually move the robotic arm away from the patient or out of the way. Summary of the Invention [Means for solving the problem]

[0003] This disclosure describes a method and circuit for quickly stopping a motor using hardware control, rather than firmware or software control. Hardware control for stopping a motor can be beneficial in a fault or emergency stop situation, since it allows the motor to be stopped quickly even if there is a fault in one of the sensors or components normally used for robotic control. Quickly stopping a motor on a medical system can be important to ensure that the robot arm and associated medical tool do not move significantly after a fault is detected, which in turn improves patient safety.

[0004] When a robot joint is stopped under closed-loop control (e.g., in a non-fault scenario), the kinetic energy of the joint is converted to electrical energy by the motor, which returns to the voltage bus. The electrical energy returning to the voltage bus can raise the voltage of the bus unless a resistor is included that can convert some of the energy into heat to prevent large voltage spikes. The closed-loop control can manage the current passing through the motor, and therefore can quickly remove (or convert) the kinetic energy.

[0005] In an emergency stop scenario involving a robotic arm joint, kinetic energy can be removed from the joint and converted into mechanical energy (e.g., associated with friction caused by brakes) and / or thermal energy (e.g., heat generated by resistors). However, in some configurations, the brakes in a robotic arm are sized primarily for static holding and therefore may not provide enough friction to stop the joint quickly. Furthermore, converting all of the kinetic energy into friction can cause the brakes to wear out prematurely.

[0006] Shunting a motor provides a way to transfer some of the energy from the motor and convert it to heat using resistors, for example by shunting individual phases (e.g., by controlling transistors) or by shunting the entire bus. In some robotic systems, the motors have low internal resistance and therefore current spikes can occur if the motor is shunted without additional external resistance. The current spikes can be limited or reduced by adding additional resistance in the shunt path.

[0007] Thus, in one aspect, a medical system includes a motor of a robotic component, a driver circuit coupled to the motor, and a shunt circuit coupled to the driver circuit and configured to shunt the driver circuit to stop the motor for a set amount of time, the shunt circuit comprising a capacitor (C) and a first resistor (R), the capacitor and the first resistor having an RC time constant, the set amount of time corresponding to the RC time constant.

[0008] In another aspect, a medical system includes a motor of a robotic component, a driver circuit coupled to the motor, and a shunt circuit coupled to the driver circuit and configured to shunt the driver circuit to stop the motor. The shunt circuit includes a first switch coupling the driver circuit to a voltage source, a second switch coupling the driver circuit to an electrical ground, a current sensor coupled to the driver circuit and configured to measure a current in the driver circuit, and a control component coupled to the current sensor, the first switch, and the second switch. The control component is configured to open the first switch and selectively open and close the second switch in response to a fault signal to maintain the current in the driver circuit within a set range while stopping the motor.

[0009] In another aspect, a medical system includes a motor of a robotic component, a driver circuit coupled to the motor, and a shunt circuit coupled to the driver circuit, the shunt circuit including a switch electrically coupled between a high voltage rail of the driver circuit and an electrical ground, a resistor electrically coupled between the high voltage rail of the driver circuit and an electrical ground, and a capacitor coupled to the switch for shunting the driver circuit for a set amount of time.

[0010] In another aspect, a method for stopping a motor of a robotic component includes driving the motor through a driver circuit and receiving a fault signal while the motor is being driven. In response to the fault signal, the drive circuit is shunted to stop the motor. The shunting includes decoupling a driver circuit for the motor from a voltage source and coupling the driver circuit to electrical ground through a resistor, the driver circuit being decoupled from the electrical ground according to a charge draining from a capacitor. In some embodiments, the method is performed by one or more processors executing instructions stored in a memory.

[0011] In yet another aspect, a method for stopping a motor of a robotic component includes driving the motor through a driver circuit and receiving a fault signal while the motor is being driven. In response to the fault signal, the drive circuit is shunted to stop the motor. The shunting includes disconnecting a driver circuit for the motor from a voltage source and selectively coupling the driver circuit to electrical ground until the motor is stopped. The selective coupling includes monitoring a current in the driver circuit and disconnecting the driver circuit from electrical ground according to the current exceeding a first predetermined threshold and recoupling the driver circuit to electrical ground according to the current falling below a second predetermined threshold. In some embodiments, the method is performed by one or more processors executing instructions stored in a memory.

[0012] The systems, methods, and devices of the present disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein. [Brief description of the drawings]

[0013] The disclosed aspects are hereinafter described in conjunction with the accompanying drawings, in which like designations refer to like elements and which illustrate, but do not limit, the disclosed aspects. [Figure 1]1 illustrates one embodiment of a cart-based robotic system positioned for diagnostic and / or therapeutic bronchoscopy procedure(s), according to some embodiments. [Diagram 2] 2 illustrates further aspects of the robotic system of FIG. 1, according to some embodiments. [Diagram 3] 2 illustrates an embodiment of the robotic system of FIG. 1 positioned for ureteroscopy, according to some embodiments. [Figure 4] 2 illustrates an embodiment of the robotic system of FIG. 1 positioned for a vascular procedure, according to some embodiments. [Diagram 5] 1 illustrates one embodiment of a table-based robotic system positioned for a bronchoscopic procedure, according to some embodiments. [Figure 6] 1 illustrates an example of a system configured to accommodate a robotic arm(s), according to some embodiments. [Figure 7] 1 illustrates an alternative embodiment of a table-based robotic system, according to some embodiments. [Figure 8] FIG. 8 is an end view of the table-based robotic system of FIG. 7, in accordance with some embodiments. [Figure 9] FIG. 1 illustrates an end view of a table-based robotic system with an attached robotic arm, according to some embodiments. [Figure 10] 1 illustrates an exemplary instrument driver, according to some embodiments. [Figure 11] 1 illustrates an exemplary medical instrument having paired instrument drivers, according to some embodiments. [Figure 12] 13A-13C show alternative designs for the instrument driver and instrument, where the axis of the drive unit is parallel to the axis of the elongated shaft of the instrument, according to some embodiments. [Figure 13] 1 illustrates an instrument having an instrument-based insertion architecture, according to some embodiments. [Figure 14] 1 illustrates an example controller, according to some embodiments. [Figure 15A]1 illustrates an example motor driver circuit for a motor, according to some embodiments. [Figure 15B] 15B illustrates an example shunt path for the example motor driver circuit of FIG. 15A in accordance with some embodiments. [Figure 15C] 15B illustrates an example shunt path for the example motor driver circuit of FIG. 15A in accordance with some embodiments. [Figure 16A] 1 illustrates an example shunt circuit for a motor, according to some embodiments. [Figure 16B] 16B illustrates an exemplary operating state of the shunt circuit of FIG. 16A according to some embodiments. [Figure 16C] 16B illustrates an exemplary operating state of the shunt circuit of FIG. 16A according to some embodiments. [Figure 16D] 16B illustrates an exemplary operating state of the shunt circuit of FIG. 16A according to some embodiments. [Figure 17A] 16B illustrates an example shunt characteristic of the shunt circuit of FIG. 16A according to some embodiments. [Figure 17B] 16B illustrates an example shunt characteristic of the shunt circuit of FIG. 16A according to some embodiments. [Figure 18] 1 illustrates another example shunt circuit for a motor, according to some embodiments. [Figure 19A] 19 illustrates an example shunt characteristic of the shunt circuit of FIG. 18 in accordance with some embodiments. [Figure 19B] 19 illustrates an example shunt characteristic of the shunt circuit of FIG. 18 in accordance with some embodiments. [Figure 19C] 19 illustrates an example shunt characteristic of the shunt circuit of FIG. 18 in accordance with some embodiments. [Figure 19D] 19 illustrates an example shunt characteristic of the shunt circuit of FIG. 18 in accordance with some embodiments. [Figure 20A] 1 is a flowchart illustrating an exemplary method for shunting a motor, according to some embodiments. [Figure 20B]1 is a flowchart illustrating an exemplary method for shunting a motor, according to some embodiments. [Figure 21] FIG. 1 is a schematic diagram illustrating electronic components of a medical system according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 1. Overview. Aspects of the present disclosure may be integrated into a robot-enabled medical system capable of performing a variety of medical procedures, including both minimally invasive procedures such as laparoscopy, and non-invasive procedures such as endoscopy. Among endoscopic procedures, the system may perform bronchoscopy, ureteroscopy, gastroscopy, etc.

[0015] In addition to performing a wide range of procedures, the system may provide additional benefits such as enhanced imaging and guidance to assist the physician. Furthermore, the system may provide the physician with the ability to perform procedures with improved ease of use, such that a single user may control one or more of the instruments of the system.

[0016] Various embodiments are described below, by way of example only, in conjunction with the drawings, and it will be appreciated that many other implementations of the concepts of the present disclosure are possible, and various advantages may be achieved by implementations of the present disclosure.

[0017] A. Robotic System - Cart. A robot-enabled medical system may be configured in a variety of ways depending on the particular procedure. FIG. 1 illustrates one embodiment of a cart-based robot-enabled system 10 arranged for a diagnostic and / or therapeutic bronchoscopy procedure. During a bronchoscopy procedure, the system 10 may include a cart 11 having one or more robotic arms 12 for delivering a medical instrument, such as a steerable endoscope 13, which may be a procedure-specific bronchoscope for bronchoscopy, to a natural orifice access point (i.e., the mouth of a patient positioned on a table in this example) for delivering diagnostic and / or therapeutic tools. As shown, the cart 11 may be positioned adjacent to the patient's upper torso to provide access to the access point. Similarly, the robotic arms 12 may be actuated to position a bronchoscope relative to the access point. The arrangement of FIG. 1 may also be utilized when performing a gastrointestinal (GI) procedure using a gastroscope. FIG. 2 depicts an example embodiment of the cart in more detail.

[0018] With continued reference to FIG. 1, once the cart 11 is properly positioned, the robotic arm 12 can insert the steerable endoscope 13 into the patient robotically, manually, or a combination thereof. As shown, the steerable endoscope 13 can include at least two nested parts, such as an inner leader section and an outer sheath section, each section coupled to a separate instrument driver from a set of instrument drivers 28, each instrument driver coupled to the distal end of an individual robotic arm. This linear arrangement of the instrument drivers 28, which facilitates coaxial alignment of the leader section with the sheath section, creates a "virtual rail" 29 that can be repositioned in space by manipulating one or more of the robotic arms 12 to different angles and / or positions. The virtual rails described herein are depicted in the figures (such as FIGS. 3 and 4) using dashed lines, and thus the dashed lines do not depict any physical structure of the system. Translation of the instrument driver 28 along the virtual rail 29 nests the inner leader section relative to the outer sheath section, or advances or retracts the endoscope 13 from the patient. The angle of the virtual rail 29 may be adjusted, translated, or pivoted based on clinical application or physician preference. For example, in bronchoscopy, the angle and position of the virtual rail 29 shown represents a compromise between providing the physician access to the endoscope 13 and minimizing friction that results from bending the endoscope 13 into the patient's mouth.

[0019] The endoscope 13 can be directed downstream of the patient's trachea and lungs after insertion using precise commands from the robotic system until the target destination or surgical site is reached. The endoscope 13 can be manipulated to telescope the inner leader portion from the outer sheath portion to enhance articulation and increase bend radius to enhance navigation through the patient's pulmonary network and / or reach a desired target. The use of a separate instrument driver 28 also allows the leader and sheath portions to be driven independently of one another.

[0020] For example, the endoscope 13 may be oriented to deliver a biopsy needle to a target, such as a lesion or nodule in the patient's lung. The needle may be deployed through a working channel that runs the length of the endoscope to obtain a tissue sample that is analyzed by a pathologist. Depending on the results of the pathology, additional tools may be deployed through the working channel of the endoscope for additional biopsies. After identifying the nodule as malignant, the endoscope 13 may endoscopically deliver a tool to ablate the potential cancerous tissue. In some cases, the diagnostic and therapeutic treatments may be delivered in separate procedures. In other cases, the diagnostic and therapeutic treatments may be delivered during the same procedure.

[0021] The system 10 may also include a movable tower 30 that may be connected to the cart 11 via a support cable and provide support for control, electronics, fluidics, optics, sensors, and / or power to the cart 11.

[0022] To support the robotic system described above, the tower 30 may include computer-based control system component(s) that store computer program instructions in a non-transitory computer-readable storage medium, such as, for example, a persistent magnetic storage drive, a solid-state drive, or the like. Execution of these instructions, whether execution occurs in the tower 30 or in the cart 11, may control the entire system or its subsystem(s). For example, when executed by a processor in the computer system, the instructions may cause the robotic system components to actuate the carriage and arm mounts, actuate the robotic arm, and control medical instruments. For example, in response to receiving control signals, motors in the joints of the robotic arm may position the arm in a particular pose.

[0023] The tower 30 may also include pumps, flow meters, valve controls, and / or fluid access to provide controlled irrigation and aspiration capabilities to a system that may be deployed through the endoscope 13. These components may also be controlled using the computer system of the tower 30. In some embodiments, irrigation and aspiration capabilities may be provided directly to the endoscope 13 via separate cable(s).

[0024] The tower 30 may also include support equipment for sensors deployed throughout the robotic system 10. For example, the tower 30 may include optoelectronic equipment for detecting, receiving, and processing data received from optical sensors or cameras anywhere in the robotic system 10. In combination with a control system, such optoelectronic equipment may be used to generate real-time images for display in any number of consoles located throughout the system, including in the tower 30. Similarly, the tower 30 may also include electronic subsystems for receiving and processing signals from deployed electromagnetic (EM) sensors. The tower 30 may also be used to house and position EM field generators for detection by EM sensors in or on a medical instrument.

[0025] The tower 30 may also include a console 31 in addition to other consoles available to the rest of the system, for example a console mounted on top of a cart. The console 31 may include a user interface and a display screen, such as a touch screen, for the operator physician. The consoles in the system 10 are generally designed to provide both pre-operative and real-time information of the procedure, such as robotic control and navigation and localization information for the endoscope 13. If the console 31 is not the only console available to the physician, the console 31 may be used by a second operator, such as a nurse, to provide procedure-specific data, such as navigation and localization information, as well as monitor the patient's health or vitals and the operation of the system 10. In other embodiments, the console 31 is housed in a body separate from the tower 30.

[0026] FIG. 2 provides a detailed view of one embodiment of a cart 11 from the cart-based robot-enabled system shown in FIG. 1. The cart 11 generally includes an elongated support structure 14 (often referred to as a "column"), a cart base 15, and a console 16 at the top of the column 14. The column 14 may include one or more carriages, such as a carriage 17 (alternatively an "arm support") for supporting the deployment of one or more robotic arms 12 (three are shown in FIG. 2). The carriage 17 may include individually configurable arm mounts that rotate along orthogonal axes to adjust the base of the arm 12 for better positioning relative to the patient. The carriage 17 also includes a carriage interface 19 that allows the carriage 17 to translate vertically along the column 14.

[0027] The carriage interface 19 is connected to the column 14 through slots, such as slots 20 positioned on either side of the column 14 to guide the vertical translation of the carriage 17. The slots 20 include vertical translation interfaces for positioning and holding the carriage 17 at various vertical heights relative to the cart base 15. The vertical translation of the carriage 17 allows the cart 11 to adjust the reach of the robotic arm 12 to meet various table heights, patient sizes, and physician preferences. Similarly, an individually configurable arm mount on the carriage 17 allows the robotic arm base 21 of the robotic arm 12 to be angled in various configurations.

[0028] Column 14 may contain mechanisms therein, such as gears and motors, designed to use a vertically aligned leadscrew to mechanically translate carriage 17 in response to control signals generated in response to user input, such as input from console 16.

[0029] The robotic arm 12 may generally include a robotic arm base 21 and an end effector 22 separated by a series of links 23 connected by a series of joints 24, each joint including an independent actuator, each actuator including an independently controllable motor. Each independently controllable joint represents an independent degree of freedom available to the robotic arm 12. Each of the robotic arms 12 may have seven joints, thus providing seven degrees of freedom. A large number of joints results in a large number of degrees of freedom, allowing for "redundant" degrees of freedom. Redundant degrees of freedom allow the robotic arm 12 to position its respective end effector 22 at a specific position, orientation, and trajectory in space using different link positions and joint angles. This allows the system to position and orient the medical instrument from a desired point in space, while allowing the physician to move the arm joints to a clinically advantageous position away from the patient to create greater access while avoiding arm collisions.

[0030] The cart base 15 balances the weight of the column 14, carriage 17, and robotic arm 12 on the floor. Thus, the cart base 15 houses the heavier parts such as electronics, motors, power supplies, and components that allow the cart 11 to be either mobile and / or immobilized. For example, the cart base 15 includes casters 25 in the form of rollable wheels that allow the cart 11 to be easily moved around the room before a procedure. After reaching the proper position, the casters 25 can be immobilized using wheel locks to hold the cart 11 in place during a procedure.

[0031] A console 16 positioned at the vertical end of column 14 allows for both a user interface and a display screen (or dual-purpose device such as, for example, a touch screen 26) for receiving user input to provide both pre-operative and intra-operative data to the physician user. Potential pre-operative data on the touch screen 26 may include pre-operative planning, navigation and mapping data derived from a pre-operative computed tomography (CT scan), and / or notes from a pre-operative patient interview. Intra-operative data on the display may also include vital patient statistics such as respiration, heart rate, and / or pulse, along with optical information provided from tools, sensor information from sensors, and coordinate information.

[0032] 3 shows an embodiment of the robot-enabled system 10 positioned for ureteroscopy. In a ureteroscopy procedure, the cart 11 can be positioned to deliver a ureteroscope 32, a procedure-specific endoscope designed to follow the patient's urethra and ureters, to the patient's lower abdominal region. As shown, the cart 11 can be aligned to a table leg to allow the robotic arm 12 to position the ureteroscope 32 for direct linear access to the patient's urethra. From the table leg, the robotic arm 12 can insert the ureteroscope 32 along a virtual rail 33 through the urethra directly into the patient's lower abdomen.

[0033] After insertion into the urethra using control techniques similar to those in bronchoscopy, the ureteroscope 32 can be navigated to the bladder, ureters, and / or kidneys for diagnostic and / or therapeutic applications. For example, the ureteroscope 32 can be directed to the ureter and kidney to fragment accumulated kidney stones using a laser lithotriptor or ultrasonic lithotriptor device deployed through the working channel of the ureteroscope 32. After lithotripsy is complete, the resulting stone fragments can be removed using a basket deployed through the ureteroscope 32.

[0034] FIG. 4 shows an embodiment of the robot-enabled system 10 similarly positioned for a vascular procedure. In a vascular procedure, the system 10 may be configured such that the cart 11 can deliver a medical instrument 34, such as a steerable catheter, to an access point in the femoral artery in the patient's leg. As in a ureteroscopy procedure, the cart 11 may be positioned toward the patient's leg and lower abdomen to allow the robotic arm 12 to provide a virtual rail 35 with direct linear access to the femoral artery access point in the patient's thigh / hip region. After insertion into the artery, the medical instrument 34 may be oriented and inserted by translating the instrument driver 28. Alternatively, the cart may be positioned around the patient's upper abdomen to reach alternative vascular access points, such as the carotid and brachial arteries near the shoulder and wrist.

[0035] B. Robot system-table. An embodiment of a robot-enabled medical system may also incorporate a patient table. The incorporation of a table may reduce the amount of capital equipment in the operating room by removing the cart, allowing better access to the patient. FIG. 5 shows one embodiment of such a robot-enabled system deployed for a bronchoscopy procedure. The system 36 includes a support structure or column 37 for supporting a platform 38 (shown as a "table" or "bed") across the floor. Much like a cart-based system, the end effector of the robotic arm 39 of the system 36 includes an instrument driver 42 that is designed to manipulate an elongated medical instrument, such as the bronchoscope 40 of FIG. 5, through or along a virtual rail 41 formed from the linear alignment of the instrument driver 42. In practice, a C-arm for providing fluoroscopic imaging may be positioned above the upper abdominal region of the patient by placing emitters and detectors around the table 38.

[0036] As shown, column 37 may include one or more carriages 43, shown in system 36 as ring-shaped, that may be a base for one or more robotic arms 39. The carriages 43 may translate along a vertical column interface 44 that runs the length of column 37 to provide different viewing positions from which the robotic arms 39 may be positioned to reach the patient. The carriage(s) 43 may rotate about column 37 using a mechanical motor positioned within column 37 to allow the robotic arms 39 to access multiple sides of table 38, for example, both sides of the patient.

[0037] The system 36 may also include a tower (not shown) that divides the functionality of the system 36 between the table and the tower to reduce the form factor and bulk of the table. As with the previously disclosed embodiments, the tower may provide various support functions to the table, such as processing, computing, and control capabilities, power, fluidics, and / or optical and sensor processing. The tower may also be mobile for positioning away from the patient to improve physician access and keep the operating room clutter-free. The tower may also include a master controller or console that provides both a user interface for user input, such as a keyboard and / or pendant, and a display screen (or touch screen) for pre-operative and intra-operative information, such as real-time imaging, navigation, and tracking information. In some embodiments, the tower may also include a holder for a gas tank used for venting.

[0038] In some embodiments, the table base may house and store the robotic arm when not in use. Figure 6 illustrates a system 47 for housing the robotic arm in one embodiment of a table-based system. In the system 47, the carriage 48 may be translated vertically into the base 49 to house the robotic arm 50, arm mount 51, and carriage 48 within the base 49. The base cover 52 may be translated and retracted open to deploy the carriage 48, arm mount 51, and arm 50 about the column 53, and closed to store and protect them when not in use.

[0039] 7 and 8 show isometric and end views of one embodiment of a table-based surgical robotic system 100. The surgical robotic system 100 includes one or more adjustable arm supports 105 that can be configured to support one or more robotic arms relative to the table 101 (see, e.g., FIG. 9). In the illustrated embodiment, only one adjustable arm support 105 is shown, but additional arm supports can be provided on the opposite side of the table 101. The adjustable arm support 105 can be configured to move relative to the table 101 to adjust and / or change the position of the adjustable arm support 105 and / or any robotic arm attached thereto relative to the table 101. For example, the adjustable arm support 105 can be adjusted with one or more degrees of freedom relative to the table 101. The adjustable arm support 105 provides the system 100 with great versatility, including the ability to easily accommodate one or more adjustable arm supports 105 and any robotic arms attached thereto under the table 101. The adjustable arm support 105 can be raised from a stowed position to a position below the top surface of the table 101. In other embodiments, the adjustable arm support 105 can be raised from a stowed position to a position above the top surface of the table 101.

[0040] The adjustable arm support 105 can provide several degrees of freedom, including lift, lateral translation, tilt, etc. In the illustrated embodiment of FIGS. 7 and 8, the arm support 105 is configured with four degrees of freedom, which are illustrated by arrows in FIG. 7. The first degree of freedom allows adjustment of the adjustable arm support 105 in the z-direction ("Z-lift"). For example, the adjustable arm support 105 can include a carriage 109 configured to move up and down along or relative to the column 102 that supports the table 101. The second degree of freedom can allow the adjustable arm support 105 to tilt. For example, the adjustable arm support 105 can include a rotational joint, which can allow the adjustable arm support 105 to align with the bed in the Trendelenburg position. The third degree of freedom allows the adjustable arm support 105 to "pivot up," which can be used to adjust the distance between the side of the table 101 and the adjustable arm support 105. A fourth degree of freedom may allow translation of the adjustable arm support 105 along the longitudinal length of the table.

[0041] The surgical robotic system 100 of Figures 7 and 8 may include a table supported by a column 102 mounted to a base 103. The base 103 and column 102 support the table 101 against a support surface. A bed axis 131 and a support axis 133 are shown in Figure 8.

[0042] An adjustable arm support 105 can be mounted to the column 102. In other embodiments, the arm support 105 can be mounted to the table 101 or the base 103. The adjustable arm support 105 can include a carriage 109, a bar or rail connector 111, and a bar or rail 107. In some embodiments, one or more robot arms mounted to the rail 107 can translate and move relative to each other.

[0043] 9 illustrates an end view of a surgical robotic system 140A with two adjustable arm supports 105A, 105B mounted on either side of a table 101. A first robotic arm 142A is attached to a bar or rail 107A of the first adjustable arm support 105B. The first robotic arm 142A includes a base 144A attached to the rail 107A. The distal end of the first robotic arm 142A includes an instrument drive mechanism 146A that can be attached to one or more robotic medical instruments or tools. Similarly, the second robotic arm 142B includes a base 144B attached to the rail 107B. The distal end of the second robotic arm 142B includes an instrument drive mechanism 146B. The instrument drive mechanism 146B can be configured to attach to one or more robotic medical instruments or tools.

[0044] In some embodiments, one or more of the robotic arms 142A, 142B comprises an arm with seven or more degrees of freedom. In some embodiments, one or more of the robotic arms 142A, 142B can include eight degrees of freedom, including an insertion axis (one degree of freedom including insertion), wrist (three degrees of freedom including wrist pitch, yaw and roll), elbow (one degree of freedom including elbow pitch), shoulder (two degrees of freedom including shoulder pitch and yaw), and base 144A, 144B (one degree of freedom including translation). In some embodiments, the insertion degree of freedom can be provided by the robotic arms 142A, 142B, while in other embodiments, the instrument itself provides the insertion via an instrument-based insertion architecture.

[0045] C. Instrument drivers and interfaces. The end effectors of the robotic arm of the system may be (i) an instrument driver (alternatively called an "instrument drive mechanism" or "instrument device manipulator") incorporating electromechanical means for actuating the medical instrument, and (ii) one that includes a removable or detachable medical instrument and does not include electromechanical components such as a motor. This dichotomy may be caused by the need to sterilize the medical instruments used in medical procedures and the inability to adequately sterilize expensive capital equipment due to the complex mechanical assembly and sensitive electronics of the medical instruments. Thus, the medical instruments may be designed to be detached, removed, and replaced from the instrument driver (and thus the system) upon individual sterilization or disposal by the physician or physician's staff. In contrast, the instrument driver does not need to be replaced or sterilized and may be draped for protection.

[0046] FIG. 10 illustrates an exemplary instrument driver. The instrument driver 162, positioned at the distal end of the robotic arm, is comprised of one or more drive units 163 arranged with parallel axes to provide a controlled torque to the medical instrument via a drive shaft 164. Each drive unit 163 includes an individual drive shaft 164 for interacting with the instrument, a gearhead 165 for converting motor shaft rotation to a desired torque, a motor 166 for generating the drive torque, an encoder 167 for measuring the rotational speed of the motor shaft and providing feedback to the control circuit, and a control circuit 168 for receiving control signals to operate the drive unit. Each drive unit 163 is controlled and motorized independently of the others, and the instrument driver 162 may provide multiple (four shown in FIG. 11) independent drive outputs to the medical instrument. In operation, the control circuit 168 would receive the control signal, send a motor signal to the motor 166, compare the resulting motor rotational speed measured by the encoder 167 to a desired speed, and modulate the motor signal to generate the desired torque.

[0047] In procedures requiring a sterile environment, the robotic system may incorporate a drive interface, such as a sterile adapter connected to a sterile drape, located between the instrument driver and the medical instrument. The primary purpose of the sterile adapter is to transfer angular motion from the drive shaft of the instrument driver to the drive input of the instrument while maintaining physical separation between the drive shaft and the drive input, and thus sterility. Thus, an exemplary sterile adapter may include a set of rotational inputs and outputs intended to mate with the drive shaft of the instrument driver and a drive input for the instrument. The sterile drape, which is connected to the sterile adapter, is constructed of a thin flexible material, such as a clear or translucent plastic, and is designed to cover the instrument driver, the robot arm, and capital equipment, such as a cart (in a cart-based system) or a table (in a table-based system). The use of the drape allows the capital equipment to be positioned in close proximity to the patient while still being located in an area that does not require sterility (i.e., the non-sterile field). On the other side of the sterile drape, the medical instrument may interface with the patient in an area that requires sterility (i.e., the sterile field).

[0048] D. Medical equipment. 11 illustrates an exemplary medical instrument with a paired instrument driver. Similar to other instruments designed for use with a robotic system, the medical instrument 170 includes an elongated shaft 171 (or elongated body) and an instrument base 172. The instrument base 172, also referred to as an "instrument handle" due to its design intended for manual interaction by a physician, may include a rotary drive input 173, e.g., a receptacle, pulley, or spool, designed to mate with a drive output 174 that passes through a drive interface on an instrument driver 175, typically at the distal end of a robotic arm 176. When physically connected, latched, and / or coupled, the mating drive input 173 of the instrument base 172 may share an axis of rotation with the drive output 174 in the instrument driver 175 to allow for the transfer of torque from the drive output 174 to the drive input 173. In some embodiments, the drive output 174 may include a spline designed to mate with a receptacle on the drive input 173.

[0049] The elongated shaft 171 is designed to be delivered through either an anatomical opening or lumen, such as in an endoscope, or a minimally invasive incision, such as in a laparoscopy. The elongated shaft 171 can be either flexible (e.g., having properties similar to an endoscope) or rigid (e.g., having properties similar to a laparoscope), or can include a customized combination of both flexible and rigid sections. If designed for laparoscopy, the distal end of the rigid elongated shaft can be connected to an end effector extending from an articulating wrist formed from a clevis having at least one degree of freedom, and to a surgical tool or medical instrument, such as a grasper or scissors, that can be actuated based on a force from a tendon as the drive input rotates in response to a torque received from the drive output 174 of the instrument driver 175. If designed for endoscopy, the distal end of the flexible elongated shaft can include a steerable or controllable bend that can be articulated and bent based on a torque received from the drive output 174 of the instrument driver 175.

[0050] Torque from the instrument driver 175 is transferred downstream of the elongated shaft 171 using tendons along the shaft 171. These individual tendons, such as pull wires, can be individually secured to individual drive inputs 173 in the instrument handle 172. From the handle 172, the tendons pass along the elongated shaft 171 through one or more pull lumens and are secured to a distal portion of the elongated shaft 171 or are secured to a wrist at the distal portion of the elongated shaft. During a surgical procedure, such as a laparoscopic, endoscopic, or hybrid procedure, these tendons can be coupled to a distally mounted end effector, such as a wrist, grasper, or scissors. In such an arrangement, torque exerted on the drive input 173 would transmit tension to the tendons, thereby actuating the end effector in some manner. In some embodiments, the tendons can rotate a joint about an axis to move the end effector in one direction or another during a surgical procedure. Alternatively, a tendon may be connected to one or more jaws of a grasper at the distal end of the elongate shaft 171, where tension from the tendon causes the grasper to close.

[0051] In endoscopy, the tendons may be coupled to a bend or articulating section positioned along (e.g., at the distal end) of the elongate shaft 171 via adhesive, control rings, or other mechanical fixation. When fixedly attached to the distal end of the bend section, torque exerted on the drive input 173 is transferred to the tendons, causing the softer bend section (sometimes referred to as the articulating section or articulating region) to bend or articulate. Along the non-bend section, it may be convenient to helical or spiral the individual pull lumens that direct the individual tendons along (or inwardly) the wall of the endoscope shaft to counterbalance the radial forces resulting from tension in the pull wires. The angle of the helix and / or spacing between them may be altered or engineered for specific purposes, with narrower helices exhibiting poor shaft compression under load forces, while lesser helices provide superior shaft compression under load forces, but also limited bending. At the other end of the spectrum, orienting the pull lumen parallel to the longitudinal axis of the elongate shaft 171 can allow for controlled articulation at the desired bend or articulation.

[0052] In endoscopy, the elongated shaft 171 houses several components that aid in robotic procedures. The elongated shaft may be configured with a working channel for deploying surgical tools (or medical instruments), irrigation, and / or suction to a surgical site at the distal end of the shaft 171. The elongated shaft 171 may also house wires and / or optical fibers that carry signals at the distal tip to / from an optical assembly that may include an optical camera. The elongated shaft 171 may also house optical fibers for carrying light from a proximally located light source, such as a light emitting diode, to the distal end of the shaft.

[0053] At the distal end of the instrument 170, the distal tip may include a working channel opening for delivering tools to the surgical site for diagnosis and / or treatment, irrigation, and aspiration. The distal tip may also include a port for a camera, such as a fiberscope or digital camera, to capture images of the internal anatomical space. In this regard, the distal tip may also include a port for a light source to illuminate the anatomical space when the camera is in use. In the embodiment of FIG. 11, the drive shaft axis, and therefore the drive input axis, is orthogonal to the axis of the elongated shaft.

[0054] 12 illustrates an alternative design of the instrument driver and instrument, in which the axis of the drive unit is parallel to the axis of the elongated shaft of the instrument. As shown, a circular instrument driver 180 includes four drive units with their drive outputs 181 aligned in parallel at the end of a robotic arm 182. The drive units and their respective drive outputs 181 are housed in a rotating assembly 183 of the instrument driver 180, which is driven by one of the drive units in that assembly 183. In response to torque provided by the rotating drive units, the rotating assembly 183 rotates along a circular bearing connecting the rotating assembly 183 to a non-rotating portion 184 of the instrument driver. In other embodiments, the rotating assembly 183 may be integrated into the non-rotatable portion 184 and thus responsive to a separate drive unit that is not parallel to the other drive units. The rotation mechanism 183 enables the instrument driver 180 to rotate the drive units and their respective drive outputs 181 as a single unit about the instrument driver axis 185 .

[0055] Similar to the previously disclosed embodiments, the instrument 186 may include an elongated shaft portion 188 and an instrument base 187 (shown with a transparent exterior skin for purposes of discussion) that includes a number of drive inputs 189 (such as receptacles, pulleys, and spools) configured to receive the drive output 181 in the instrument driver 180. Unlike the previously disclosed embodiments, the instrument shaft 188 extends from the center of the instrument base 187, with the axis being substantially parallel to the axis of the drive input 189, rather than orthogonal as seen in the design of FIG.

[0056] When coupled to the rotation assembly 183 of the instrument driver 180, a medical instrument 186, including an instrument base 187 and an instrument shaft 188, rotates with the rotation assembly 183 about the instrument driver axis 185. Because the instrument shaft 188 is positioned in the center of the instrument base 187, the instrument shaft 188 is coaxial with the instrument driver axis 185 when attached. Thus, rotation of the rotation assembly 183 causes the instrument shaft 188 to rotate about its own longitudinal axis.

[0057] 13 illustrates an instrument having an instrument-based insertion architecture, according to some embodiments. The instrument 200 can be coupled to any of the instrument drivers discussed above. The instrument 200 includes an elongate shaft 202, an end effector 212 connected to the elongate shaft 202, and a handle 220 coupled to the elongate shaft 202. The elongate shaft 202 includes a tubular member having a proximal portion 204 and a distal portion 206. Manipulation of one or more of the cables 230a (e.g., via the instrument driver) results in actuation of the end effector 212.

[0058] The instrument handle 220, sometimes referred to as the instrument base, may typically include a mounting interface 222 having one or more mechanical inputs 224, e.g., receptacles, pulleys, or spools, designed to intermate with one or more torque couplers on a mounting surface of the instrument driver.

[0059] In some embodiments, instrument 200 includes a series of pulleys or cables that allow elongate shaft 202 to translate relative to handle 220. In other words, instrument 200 itself constitutes an instrument-based insertion architecture that accommodates the insertion of the instrument, thereby minimizing reliance on a robotic arm to effect the insertion of instrument 200. In other embodiments, the robotic arm may be significantly involved in the insertion of the instrument.

[0060] E. Controller. Any of the robotic systems described herein can include an input device or controller for manipulating an instrument attached to the robotic arm. In some embodiments, the controller can be coupled (e.g., communicatively, electrically, wirelessly, and / or mechanically) to the instrument such that manipulation of the controller causes a corresponding manipulation of the instrument, e.g., via master-slave control.

[0061] 14 is a perspective view of one embodiment of the controller 242. In the illustrated embodiment, the controller 242 is configured to enable operation of two medical instruments and includes two handles 244. Each of the handles 244 is connected to a gimbal 246. Each gimbal 246 is connected to a positioning platform 248.

[0062] 14, each positioning platform 248 includes a SCARA arm (Selectively Compliant Assembly Robot Arm) 258 coupled to a column 254 by a prismatic joint 256. The prismatic joint 256 is configured to translate along the column 254 (e.g., along a rail 257) to allow each of the handles 244 to translate in the z-direction, providing a first degree of freedom. The SCARA arm 258 is configured to allow movement of the handles 244 in the xy-plane, providing an additional two degrees of freedom.

[0063] F. Navigation and Control. Traditional endoscopy may involve the use of fluoroscopy (e.g., as may be delivered through a C-arm) and other forms of radiation-based imaging modalities to provide intraluminal guidance to the operator-physician. In contrast, the robotic system contemplated by the present disclosure may provide non-radiation-based navigation and localization means to reduce the physician's exposure to radiation and reduce the amount of equipment in the operating room. As used herein, the term "localization" may refer to determining and / or monitoring the position of an object in a reference coordinate system. Techniques such as preoperative mapping, computer vision, real-time EM tracking, and robot command data may be used individually or in combination to achieve a radiation-free surgical environment. In other cases where radiation-based imaging modalities are still used, preoperative mapping, computer vision, real-time EM tracking, and robot command data may be used individually or in combination to improve information available only through radiation-based imaging modalities.

[0064] As discussed above, the robotic systems discussed herein can be designed to incorporate a combination of one or more of the above-mentioned technologies. The computer-based control system of the tower, bed, and / or cart-based robotic system can store, for example, in a non-transitory computer-readable storage medium, such as a persistent magnetic storage drive, solid-state drive, etc., computer program instructions that, when executed, cause the system to receive and analyze sensor data and user commands, generate control signals throughout the system, and display navigational and localization data, such as instrument position within a global coordinate system, anatomical maps, etc.

[0065] 2. Shunt circuits and methods for robotic devices. Embodiments of the present disclosure relate to circuits and methods for stalling motor components of a robotic system or device. Robotic systems and devices, such as those described above, may advantageously include a shunt circuit or component for dynamically stalling a motor (e.g., in response to a fault or emergency condition).

[0066] In many non-fault scenarios, the joints of the robotic system are stopped under closed-loop control where the kinetic energy of the joint is converted by the motor into electrical energy and returned to a voltage bus. This may raise the voltage of the bus, but the bus may contain resistors that allow at least a portion of the energy to be dissipated as heat to prevent large voltage spikes. In this way, the closed-loop control can control the current passing through the motor and very quickly remove the energy from the joint. In many cases, this is an efficient way to convert the kinetic energy of the joint into electrical energy. Such closed-loop control may be used when the surgeon performs remote manipulations and changes the orientation of the robotic components.

[0067] A challenge arises when one of the sensors used to monitor and control the operation of the motor fails, as the failure may prevent the use of closed-loop control. For example, closed-loop control may require the electrical angle of the motor to be known, but a failure may prevent the closed-loop control from receiving information indicative of the electrical angle. The shunt circuits and components described herein can provide hardware control to stop the motor during an emergency stop (e-stop) without having to rely on software or sensors that may be in an error state. Stopping the motor as quickly as possible during an e-stop can ensure that the robotic arm and associated medical tool do not continue to move significantly, enhancing patient safety.

[0068] Kinetic energy can be removed from a joint by converting it into other forms of energy (e.g., energy generated by friction applied by a brake, or heat energy generated by a resistor). However, using a brake to stop a joint may be inappropriate, since the brake alone may not provide enough friction to stop the joint quickly. Therefore, it may be beneficial to convert at least a portion of the kinetic energy in a motor to heat dissipation in a resistor. For example, the kinetic energy from a joint may be converted into electrical energy by a motor, which is then dissipated through one or more resistors.

[0069] Those skilled in the art will appreciate that the systems and devices described herein may also have application in non-medical situations, for example, the shunt circuits described herein may be implemented in robotic systems and devices used in non-medical environments.

[0070] FIG. 15A illustrates a motor driver circuit 300 for a motor 302, according to some embodiments. In some embodiments, the motor 302 is coupled to the motor driver circuit 300 as shown in FIG. 15A and is not part of the motor driver circuit 300. In some embodiments, the motor 302 is an actuator. The motor driver circuit 300 includes three transistor pairs (e.g., transistor pairs 304-1 and 306-1, transistor pairs 304-2 and 306-2, and transistor pairs 304-3 and 306-3) for the three-phase motor 302. In some embodiments, the transistors 304 and 306 are field-effect transistors (FETs). Each transistor 304 is coupled between a voltage line 310 and a respective input of the motor 302. In some embodiments, each transistor 304 is a PMOS transistor. Each transistor 306 is coupled between a voltage line 311 and a respective input of the motor 302. In some embodiments, each transistor 306 is an NMOS transistor. In some embodiments, at least a subset of transistors 304 and 306 are bipolar junction transistors. In some embodiments, voltage line 311 is coupled to electrical ground 308. According to some embodiments, voltage line 310 is a high voltage line (e.g., coupled to a 48 volt voltage source) and voltage line 311 is a low voltage line (e.g., coupled to electrical ground). In some embodiments, motor driver circuit 300 further includes a plurality of diodes 309 (e.g., diodes 309-1 through 309-6), each coupled in parallel with a respective transistor (e.g., diode 309-1 is in parallel with transistor 306-1 and diode 309-4 is in parallel with transistor 304-1). In some embodiments, each diode 309 has the same characteristics (e.g., the same forward voltage and the same reverse voltage), while in other embodiments, at least a subset of diodes 309 have different characteristics (e.g., different forward voltages and / or different reverse voltages).According to some embodiments, the motor driver circuit 300 further includes resistors 316 and 314 coupled to the motor 302. According to some embodiments, the motor driver circuit 300 also includes a current sensor 312 (e.g., for monitoring motor operation and / or phase) coupled to the resistor 314.

[0071] 15B and 15C show example shunt paths for the motor driver circuit 300 of FIG. 15A, according to some embodiments. FIG. 15B shows an example of a gate shunt across transistors 306-1 and 306-2. Transistors 306-1 and 306-2 of FIG. 15B are enabled simultaneously (e.g., due to a voltage applied to the gate of each transistor), thereby creating a closed loop circuit between the motor 302 and electrical ground 308. Example current flows are shown by arrows 330 and 332. In some circumstances, a gate shunt as shown in FIG. 15B may result in current spikes due to small resistance in the circuit (e.g., due to a lack of additional resistors). Such current spikes may adversely affect the motor or electronics of the robotic system.

[0072] FIG. 15C illustrates an example of a bus shunt across diodes 309-2 and 309-4 by coupling voltage line 310 to voltage line 311 to create a closed loop circuit between motor 302 and electrical ground 308. Exemplary current flow is indicated by arrows 338 and 340. In the absence of additional resistance, the bus shunt illustrated in FIG. 15C may also result in current spikes. A configuration with an external resistor (e.g., resistor 408 shown in FIG. 16A) added between voltage 310 and electrical ground 308 can limit or reduce current flow (and reduce current spikes) during shunting operation.

[0073] FIG. 16A illustrates a shunt circuit 400 for a motor 302, according to some embodiments. The shunt circuit 400 is coupled to a motor driver circuit 402 via lines 415 and 417. In some embodiments, the motor driver circuit 402 is an instance of the motor driver circuit 300 of FIG. 15A (e.g., line 415 is coupled to voltage line 310, and line 417 is coupled to voltage line 311). In FIG. 16A, the shunt circuit 400 includes switches 406 and 414, resistors 408 and 413, a capacitor 412, and a relay component 404. In some embodiments, the relay component 404 includes multiple relays (e.g., a separate relay for controlling each of the switches 406 and 414). In some embodiments, the shunt circuit 400 includes a subset of the switches 406, 414, resistor 408, resistor 413, capacitor 412, or relay component 404. According to some embodiments, the shunt circuit 400 is coupled to a voltage source 416 (e.g., providing a predetermined voltage, such as 48 volts) and electrical grounds 410-1 and 410-2. In some embodiments, the electrical grounds 410-1 and 410-2 are the same electrical ground. According to some embodiments, the relay component 404 is coupled to one or more control signals via a connection 420. According to some embodiments, the relay component 404 is coupled to a voltage source 418 (e.g., a 24 volt voltage source). In some embodiments, the relay component 404 is coupled to a plurality of control signals, and the connection 420 represents a bus connection (e.g., a parallel bus connection for independently transmitting a first control signal for controlling a first relay associated with the switch 406 and a second control signal for controlling a second relay associated with the switch 414). In some embodiments, the one or more control signals include one or more of a test signal, a motor fault signal, a voltage source signal, or an emergency stop signal. In some embodiments, the relay component 404 is or includes a solid-state relay (SSR), such as an active-low solid-state relay.

[0074] In some embodiments, resistor 408 is adapted (e.g., sized) to have a resistance sufficient to reduce the current through the motor during shunting (e.g., the current shown in FIG. 15C). In some configurations, resistor 408 prevents the current from damaging the motor or other electronics. In some embodiments, resistor 408 is adapted (e.g., sized) to have a minimum resistance sufficient to prevent the current flowing through the motor during shunting from damaging the motor or other electronics. In some configurations, by having a minimum sufficient resistance, resistor 408 can protect the motor and electronics without introducing excessive delays in stopping the motor during shunting. In some embodiments, resistor 408 has a resistance in the range of 1 ohm to 50 ohms (e.g., 5, 10, 15, 20, 25, 30, 35, 40, or 45 ohms). In some embodiments, the switch 414 is or includes a transistor (e.g., a FET), and the relay component 404 includes a transistor driver component that controls the opening and closing of the switch 414 (e.g., via a voltage applied to a gate of the transistor).

[0075] 16B-16D illustrate example operating states of the shunt circuit 400 of FIG. 16A according to some embodiments. FIG. 16B illustrates an unshunted operating state of the shunt circuit 400. According to some embodiments, the unshunted operating state represents a normal operating state of the motor 302. As illustrated in FIG. 16B, in the unshunted operating state, the switch 414 is closed (e.g., allowing current to flow between the voltage source 416 and the motor driver circuit 402) and the switch 406 is open (e.g., preventing current from flowing between the lines 415 and 417). According to some embodiments, in the unshunted operating state, the capacitor 412 is coupled to the voltage source 418 via the relay component 404 (e.g., to charge the capacitor 412). In some embodiments, the voltage source 418 is or includes a capacitor.

[0076] FIG. 16C illustrates a shunt operation state of the shunt circuit 400. As shown in FIG. 16C, in the shunt operation state, the switch 414 is open (e.g., preventing current from flowing between the voltage source 416 and the motor driver circuit 402) and the switch 406 is closed (e.g., allowing current to flow between the lines 415 and 417). In some embodiments, the shunt circuit 400 transitions to the shunt operation state in response to one or more of the control signal(s) being active. In some embodiments, the control signal(s) are active low control signals (e.g., a control signal transitioning to a low voltage (e.g., 0 volts) represents an active signal). As shown in FIG. 16C, in the shunt operation state, the motor driver circuit 402 is bus shunted across the resistor 408, thereby using the resistor 408 to convert (e.g., heat dissipate) kinetic energy from the motor 302 into thermal energy.

[0077] 16C, in a shunt operation state, the capacitor 412 is coupled to the switch 406 via the relay component 404 and the resistor 413. In some embodiments, the capacitor 412 is adapted (e.g., sized) to have a capacitance that, in combination with the resistance of the resistor 413, determines an RC time constant for how long the shunt operation occurs (e.g., how long the switch 406 remains closed) after a fault is detected. In some embodiments, the capacitor 412 has a capacitance in the range of 1 microfarad to 100 microfarads (e.g., 10, 20, 30, 40, 50, 60, 70, 80, or 90 microfarads). In some embodiments, the resistor 413 has a resistance in the range of 10 kilohms to 100 kilohms (e.g., 10, 20, 30, 40, 50, 60, 70, 80, or 90 kilohms). In some embodiments, resistor 413 and capacitor 412 are adapted to have an RC time constant in the range of 0.1 seconds to 2 seconds (e.g., 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, or 1.9 seconds).

[0078] FIG. 16D illustrates the backdrive-enabled operating state of the shunt circuit 400. As shown in FIG. 16D, in the backdrive-enabled operating state, the switch 414 is open (e.g., preventing current from flowing between the voltage source 416 and the motor driver circuit 402) and the switch 406 is open (e.g., preventing current from flowing between the lines 415 and 417). In some embodiments, the shunt circuit 400 transitions to the backdrive-enabled operating state after being in the shunt operating state. According to some embodiments, the backdrive-enabled operating state corresponds to a low stiffness state of the joint driven by the motor 302, thereby facilitating manual manipulation of the joint by an operator of the robotic system. For example, opening the switch 406 reduces resistance to manual manipulation of the joint (e.g., by an operator of the robotic system). In some embodiments, the shunt circuit 400 transitions to the backdrive-enabled operating state after being in the shunt operating state for a set amount of time. In some embodiments, the set amount of time is based on the resistor 413 and the capacitor 412. Resistor 413 has a resistance value (R) and capacitor 412 has a capacitance value (C). In some embodiments, the set amount of time corresponds to an RC time constant of resistor 413 and capacitor 412. In some embodiments, shunt circuit 400 includes one or more additional resistors coupled to capacitor 412 (not shown), and the RC time constant is based on a combination of resistances from resistor 413 and the one or more additional resistors.

[0079] 17A and 17B show example shunt characteristics for the shunt circuit 400 of FIG. 16A, according to some embodiments. FIG. 17A shows an example of the rotor speed of the motor 302 over time (represented by line 452) during the shunt operating state of FIG. 16C. FIG. 17B shows an example of the current through the motor 302 over time (represented by line 454) during the shunt operating state of FIG. 16C. In the example shown in FIG. 17A and 17B, the shunt circuit 400 switches from the non-shunted operating state to the shunt operating state at 0 seconds. According to some embodiments, the shunt circuit 400 switches from the shunt operating state to the backdrive enabled operating state (e.g., at 0.15 seconds) when the rotor speed approaches 0 radians per second. In some embodiments, the shunt circuit 400 switches from the shunt operating state to the backdrivable operating state according to a determination that the rotor speed is below a predetermined speed threshold or the current is below a predetermined current threshold. In some embodiments, the predetermined speed threshold is non-zero and the predetermined current threshold is non-zero. According to some embodiments, the resistor 413 and the capacitor 412 of the shunt circuit 400 define an RC time constant that determines when the shunt circuit 400 transitions from the shunt operating state to the backdrivable state. For example, the capacitor 412 is charged via the relay component 404 (e.g., during a non-shunting operating state) and is used to close the switch 406 during the shunting operating state. In this example, once the capacitor 412 is sufficiently drained, the switch 406 reopens (e.g., the gate of the switch 406 is no longer driven to keep the switch 406 closed).

[0080] FIG. 18 illustrates a shunt circuit 470 for the motor 302, according to some embodiments. The shunt circuit 470 is similar to the shunt circuit 400 (shown in FIG. 16A ), except that the shunt circuit 470 includes a current sensor 472 and does not include a resistor 413 or a capacitor 412. In addition, the relay component 404 of the shunt circuit 400 is replaced with a relay component 474 in the shunt circuit 470. In some embodiments, the relay component 474 is one instance of the relay component 404. According to some embodiments, the relay component 474 is configured to chopper shunt the motor driver circuit 402 by opening and closing the switch 406 during a shunt operating state (e.g., the relay component 474 repeatedly opens and closes the switch 406 for chopper shunting during the shunt operating state). For example, at a first time (e.g., upon transitioning to the shunt operating state), the relay component 474 causes the switch 406 to close. At a second time, the relay component 474 causes the switch 406 to open pursuant to the current across the resistor 408 reaching a current threshold (e.g., as measured by the current sensor 472). At a third time (e.g., a set amount of time after the second time), the relay component 474 causes the switch 406 to close again. In some embodiments, the relay component 474 repeatedly (and alternates between opening and closing) the switch 406 until the rotor speed of the motor 302 is reduced below the speed threshold. In some embodiments, the shunt circuit 470 does not include a current sensor 472 (e.g., the relay component 474 receives a current indicator from another component, such as the motor driver circuit 402). In some embodiments, the current sensor 472 determines the current provided to the resistor 408 by measuring the voltage across the resistor 408 (and based on the predetermined or known resistance of the resistor 408).

[0081] 19A-19D show example shunt characteristics of the shunt circuit 470 of FIG. 18 according to some embodiments. FIG. 19A shows an example of the change in rotor speed of the motor 302 over time during a shunt operating state (represented by line 506) when the relay component 474 chopper shunts the motor driver circuit 402. FIG. 19B shows an example of the change in current through the motor 302 over time during a shunt operating state (represented by line 508) when the relay component 474 chopper shunts the motor driver circuit 402. FIG. 19C shows an example of the change in position of the joint driven by the motor 302 over time during a shunt operating state (represented by line 510) when the relay component 474 chopper shunts the motor driver circuit 402. FIG. 19D shows another example of the change in current through the motor 302 over time during a shunt operating state (on a reduced time scale compared to FIG. 19B) (represented by line 512). According to some embodiments, dashed line 514 in Figure 19D represents the current threshold value discussed above with respect to Figure 18. For example, a local maximum (peak) in line 512 represents a current that meets the current threshold that causes relay component 474 to open switch 406. In this example, a current that increases from a local minimum (trough) in line 512 represents a current that causes relay component 474 to close switch 406 again.

[0082] In the example shown in Figures 19A-19D, the shunt circuit 470 switches from a non-shunted to a shunted operating state at 0 seconds. According to some embodiments, the shunt circuit 470 switches from a shunted to a backdrivable operating state when the rotor speed approaches 0 radians per second (e.g., at 0.06 seconds). In some situations, a chopping shunt allows for shunting of the motor using a smaller resistor compared to a non-chopper shunt (e.g., resistor 408 may have a smaller resistance in the shunt circuit 470 of Figure 18 than in the shunt circuit 400 of Figure 16A).

[0083] 20A and 20B are flow charts illustrating a method 600 for shunting the motor 10, according to some embodiments. The method 600 is implemented in a medical system (e.g., medical system 36) having one or more processors (e.g., processor(s) 280) and a memory (e.g., memory 282). In some embodiments, the memory (e.g., memory 282) stores instructions for execution by the one or more processors (e.g., processor(s) 280). In some embodiments, the medical system includes a robotic arm (e.g., is a robot-enabled medical system). In some embodiments, the robotic arm is coupled to a medical instrument.

[0084] In some embodiments, the medical system includes: (i) a motor (e.g., motor 302) of a robotic component (e.g., a robotic arm); (ii) a driver circuit (e.g., driver circuit 402) coupled to the motor; and (iii) a shunt circuit (e.g., shunt circuit 400) coupled to the driver circuit and configured to shunt the driver circuit for a set amount of time to stop the motor. In some embodiments, the shunt circuit includes a capacitor (e.g., capacitor 412) and a first resistor (e.g., resistor 413), where the capacitor and the first resistor have (e.g., are characterized by or define) an RC time constant, and where the set amount of time corresponds to the RC time constant.

[0085] In some embodiments, the medical system includes (i) a motor (e.g., motor 302) of a robotic component; (ii) a driver circuit (e.g., driver circuit 402) coupled to the motor; and (iii) a shunt circuit (e.g., shunt circuit 470) coupled to the driver circuit and configured to shunt the driver circuit to stop the motor. In some embodiments, the shunt circuit includes (a) a first switch (e.g., switch 414) coupling the driver circuit to a voltage source; (b) a second switch (e.g., switch 406) coupling the driver circuit to an electrical ground; (c) a current sensor (e.g., current sensor 472) coupled to the driver circuit and configured to measure a current in the driver circuit; and (d) a control component (e.g., relay component 474) coupled to the current sensor, the first switch, and the second switch. In some embodiments, the control component is configured to maintain a current in the driver circuit within a predetermined range while (i) opening the first switch and (ii) selectively opening and closing the second switch to stop the motor in response to a fault signal.

[0086] In some embodiments, the medical system includes (i) a motor of a robotic component (e.g., motor 302), (ii) a driver circuit (e.g., driver circuit 402) coupled to the motor, and (iii) a shunt circuit (e.g., shunt circuit 400) coupled to the driver circuit. In some embodiments, the shunt circuit includes (a) a switch (e.g., switch 406) electrically coupled between a high voltage rail (e.g., voltage rail 310) of the driver circuit and an electrical ground (e.g., electrical ground 410-1), (b) a resistor (e.g., resistor 408) electrically coupled (coupled in series with the switch) between the high voltage rail of the driver circuit and an electrical ground, and (c) a capacitor (e.g., capacitor 412) coupled (e.g., to a gate of a transistor of the switch) for shunting the driver circuit for a set amount of time (e.g., by keeping the switch closed for a set amount of time while a charge in the capacitor is drained).

[0087] The medical system drives a motor (e.g., motor 302) (box 602) via a driver circuit (e.g., driver circuit 300). In some embodiments, the medical system drives the motor using processor(s) 280 and / or control circuitry coupled to the driver circuit (e.g., control circuitry coupled to the gates of transistors 304 and 306). In some embodiments, the motor is a polyphase motor (e.g., a three-phase motor) and the driver circuit is configured to drive each of the individual phases of the polyphase motor.

[0088] In some embodiments, motors control joints of the robotic component (box 604), and the movement of the robotic component is manipulated by coordinating the operation of the motors. In some embodiments, the robotic component is an example of any one of the robotic arms previously described (e.g., robotic arms 12, 39, 50, 142, 176, 182, or 258). In some embodiments, the joints of the robotic component are an example of any one of the joints previously described (e.g., joints 24 and 256).

[0089] The medical system receives a fault signal while the motor is being driven (box 606). In some embodiments, the fault signal is received at a shunt circuit (e.g., shunt circuit 400). In some embodiments, the fault signal is received at a relay component of the shunt circuit (e.g., relay component (404)). In some embodiments, the fault signal is an active low signal (e.g., a transition to a low voltage (e.g., 0 volts) represents an active signal). In some embodiments, the fault signal is received by the shunt circuit at an input terminal (e.g., connection 420). In some embodiments, the fault signal is received from one or more processors 280 or one or more sensors of the medical system.

[0090] In some embodiments, the fault signal is one of an emergency stop signal, a fault signal from a voltage source, or a fault signal from a driver circuit (box 608). In some embodiments, the voltage source is a voltage source for the motor driver circuit (e.g., voltage source 416). In some embodiments, the voltage source is a voltage source for control circuitry of the medical system (e.g., a 24 volt, 5 volt, or 3 volt voltage source). In some embodiments, the fault signal corresponds to a test request for the shunt circuit (e.g., prior to using the medical system in a medical procedure).

[0091] The medical system shunts the driver circuit to stop the motor in response to the fault signal (box 610). For example, the medical system couples a high voltage line (e.g., voltage line 310) of the driver circuit to a low voltage line (e.g., voltage line 311) to create a closed circuit to electrical ground (e.g., electrical ground 308) (e.g., via resistor 408).

[0092] Shunting the driver circuit includes disconnecting the driver circuit for the motor from the voltage source (box 612). For example, switch 414 of shunt circuit 400 is opened to disconnect line 415 from voltage source 416. In some embodiments, the driver circuit includes a set of diodes (e.g., diode 309) in parallel with a set of phase transistors (e.g., transistors 304 and 306), and the shunt circuit shunts the driver circuit by creating a path to electrical ground through the set of diodes (e.g., the shunt circuit bus shunts the motor).

[0093] In some embodiments, the medical system opens a first switch (e.g., switch 414) coupled between the driver circuit and a voltage source to isolate the driver circuit (box 614). In some embodiments, the first switch is or includes a transistor (e.g., a FET), and the medical system opens the first switch using a transistor driver circuit (e.g., coupled to a gate of the transistor). In some embodiments, the medical system opens the first switch using a relay component (e.g., relay component 404). In some embodiments, the relay component is coupled to a gate of the transistor of the first switch.

[0094] Shunting the driver circuit includes coupling (box 616) the driver circuit (e.g., the high voltage line 415 of the driver circuit) to an electrical ground (e.g., electrical ground 410-1) via a resistor (e.g., resistor 408). In some embodiments, coupling the driver circuit to an electrical ground creates a closed circuit that includes the motor. In some embodiments, the resistor is matched (e.g., sized) based on the characteristics of the motor (e.g., the resistance of the motor and the maximum speed of the motor).

[0095] In some embodiments, the medical system closes a second switch (e.g., switch 406) coupled between the driver circuit and electrical ground to couple the driver circuit to electrical ground (box 618). In some embodiments, the second switch is or includes a transistor (e.g., a FET). In some embodiments, the medical system closes the second switch using a relay component (e.g., relay component 404). In some embodiments, the relay component is coupled to a gate of a transistor of the second switch.

[0096] In some embodiments, the medical system shunts the driver circuit using a shunt circuit (e.g., shunt circuit 400). In some embodiments, the shunt circuit includes (i) a first switch (e.g., switch 414) coupled between the driver circuit and a voltage source (e.g., voltage source 416), (ii) a second switch (e.g., switch 406) coupled between the driver circuit and an electrical ground (e.g., electrical ground 410-1), and (iii) a relay component (e.g., relay component 404) coupled (e.g., via connection 420) to a plurality of fault signal inputs. In some embodiments, the shunt circuit includes a subset of the first switch, the second switch, and the relay component. In some embodiments, the relay component 404 is configured to (a) open the first switch and close the second switch in response to a fault signal on one of the plurality of fault signal inputs, and (b) close the first switch and open the second switch a set amount of time after receiving the fault signal. In some embodiments, the relay component is directly coupled to the plurality of fault signal inputs. In some embodiments, the relay component is indirectly coupled to the multiple fault signal inputs via a multiplexer or signal combiner, such as, for example, a logical AND (or NAND) or logical OR (or NOR) gate. In some embodiments, the first switch and the second switch each include a transistor (e.g., a FET). In some embodiments, the relay component includes a solid state relay (e.g., an active low solid state relay). In some embodiments, the multiple fault signal inputs include at least one of an emergency stop signal, a fault signal from a voltage source, or a fault signal from a driver circuit.

[0097] In some embodiments, the medical system disconnects the driver circuit from electrical ground (box 620) following the draining of charge from a capacitor (e.g., capacitor 412). For example, switch 406 includes an n-type (NMOS) transistor that operates in an "on state" (e.g., as a closed switch) while the charge at the gate of the NMOS transistor is sufficiently high. In this example, the capacitor is charged before the medical system receives the fault, and the capacitor keeps the NMOS transistor in the on state until sufficient charge is drained from the capacitor.

[0098] In some embodiments, a capacitor (e.g., capacitor 412) is coupled with one or more resistors (e.g., resistor 413), and the capacitor and the one or more resistors are characterized by an RC time constant. In some embodiments, the RC time constant is between 0.5 seconds and 5 seconds. In some embodiments, the time constant is selected to stop the motor based on a worst case scenario (e.g., maximum speed movement when a fault occurs). In some embodiments, the capacitor has a capacitance in the range of 1 microfarad to 100 microfarads. In some embodiments, the one or more resistors have a resistance in the range of 10 kilohms to 100 kilohms (e.g., 50 kilohms).

[0099] In some embodiments, the medical system disconnects the driver circuit from electrical ground according to the charge draining from the capacitor. For example, the switch 406 includes a p-type (PMOS) transistor that operates in an "on state" (e.g., as a closed switch) while the charge at the gate of the PMOS transistor is sufficiently low. In this example, the begins to charge when the medical system enters a shunt operating state, and the capacitor keeps the PMOS transistor in the on state until sufficient charge accumulates in the capacitor.

[0100] In some embodiments, the medical system directs current from the motor to a resistor (e.g., resistor 408) coupled in series with a second switch (e.g., switch 406) (box 622). In some embodiments, the shunt circuit includes a resistor (e.g., resistor 408) coupled in series with the second switch. In some embodiments, the resistor is sized to provide sufficient resistance to prevent the motor from overheating without introducing excessive delays in stopping the motor.

[0101] In some embodiments, the driver circuitry includes a set of diodes (e.g., diode 309) in parallel with a set of phase transistors (e.g., transistors 304 and 306) (box 624), and shunting includes creating a path to electrical ground through the set of diodes (e.g., as shown in FIG. 15C).

[0102] In some embodiments, the medical system performs the shunt as part of a start-up process for the robotic components (box 626). In some embodiments, the medical system is configured to test the shunt circuit as part of a start-up (power-on) process. In some embodiments, the medical system performs the shunt as part of a testing sequence prior to performing a medical procedure (e.g., a surgical procedure) on a patient. In some embodiments, the medical system performs the shunt periodically (e.g., daily, weekly, or monthly) to test the operation of the shunt circuit and / or the motor driver circuit.

[0103] In some embodiments, the medical system maintains the driver circuit in a backdriveable state after disconnecting the driver circuit from electrical ground according to the charge draining from the capacitor (box 628). In some embodiments, the medical system maintains the driver circuit in a backdriveable state (e.g., as shown in FIG. 16D ) by disconnecting the driver circuit's voltage line (e.g., high voltage line) from any voltage source or electrical ground. In some embodiments, the medical system maintains the driver circuit in a backdriveable state after the capacitor (e.g., capacitor 412) drains enough charge that it cannot keep switch 406 closed. In some embodiments, the medical system maintains the driver circuit in a backdriveable state until the fault signal is cleared or overridden, or until the medical system is reset or restarted (e.g., after the source of the fault signal is addressed).

[0104] In some embodiments, a method for stopping a motor (e.g., motor 302) of a robotic component includes (i) driving the motor via a driver circuit (e.g., driver circuit 402); (ii) receiving a fault signal while the motor is being driven (e.g., receiving the fault signal at relay component 404); and (iii) in response to the fault signal, shunting the driver circuit (e.g., using shunt circuit 400) to stop the motor, including (a) disconnecting the driver circuit for the motor from a voltage source (e.g., disconnecting the high voltage line of the driver circuit from the voltage source); and (b) coupling the driver circuit to electrical ground via a resistor (e.g., coupling the high voltage line of the driver circuit to electrical ground 410-1), such that the driver circuit is disconnected from the electrical ground as a charge drains from a capacitor (e.g., capacitor 412).

[0105] In some embodiments, a method for stopping a motor (e.g., motor 302) of a robotic component includes (i) driving the motor via a driver circuit (e.g., driver circuit 402); (ii) receiving a fault signal while the motor is being driven (e.g., receiving a fault signal at relay component 474); and (iii) in response to the fault signal, shunting the driver circuit (e.g., via shunt circuit 470) to stop the motor, including (a) disconnecting the driver circuit for the motor from a voltage source (e.g., voltage source 416); and (b) selectively coupling a high voltage line of the driver circuit to electrical ground (e.g., electrical ground 410-1) until the motor is stopped. In some embodiments, the selective coupling includes (i) monitoring the current in the driver circuit (e.g., via current sensor 472); (ii) disconnecting the driver circuit from electrical ground in response to the current exceeding a first predetermined threshold (e.g., dashed line 514); and (iii) recoupling the driver circuit to electrical ground in response to the current falling below a second predetermined threshold (e.g., as shown in FIGS. 19A-19D).

[0106] 3. Implementation Systems and Terminology. FIG. 21 is a schematic diagram showing electronic components of a system 279 (e.g., a medical and / or robotic system). In some embodiments, the system 279 is an example of one of the systems 10, 36, 47, 100, and 140A. The system 279 includes one or more processors 280 in communication with a computer-readable storage medium 282 (e.g., computer storage elements such as random access memory, read-only memory, static random access memory, and non-volatile memory, as well as other storage devices such as hard drives, optical disks, magnetic tape recordings, or any combination thereof) that store instructions for performing any of the methods described herein (e.g., the operations described with respect to FIGS. 20A and 20B). In some embodiments, the one or more processors 280 are in communication with a user interface 298. In some embodiments, the user interface 298 includes one or more human-machine interface (HMI) components, such as a console (e.g., console 31), a display (e.g., touch screen 26), a speaker, and / or a warning light (e.g., LED).

[0107] The one or more processors 280 also communicate (via a system bus or any suitable electrical circuitry) with an input / output controller 284. The input / output controller 284 receives user input from an input device 286 (e.g., the robotic arm 182 or the instrument 200) and, optionally, sensor data from one or more sensors 287, and relays the data and user input to the one or more processors 280. The input / output controller 284 also receives instructions and / or data from the one or more processors 280 and relays the instructions and / or data to one or more motors (e.g., actuators and motors for driving a robotic arm of the system), such as motors 292-1 and 292-2. In some embodiments, the input / output controller 284 is coupled to one or more motor controllers 290 and provides instructions and / or data to at least a subset of the one or more motor controllers 290, which in turn provide control signals to selected motors 292. In some embodiments, the one or more motor controllers 290 are integrated with the input / output controller 284, which provides control signals directly to the one or more motors 292 (e.g., without a separate actuator controller).

[0108] The system 279 also includes a shunt component 294 (e.g., shunt circuit 400 or 470). In some embodiments, the shunt component 294 is coupled to (e.g., in communication with) the input / output controller 284 and / or the motor controller 290. In some embodiments, the shunt component 294 is coupled to (e.g., in communication with) one or more of the motors 292. For example, the shunt component 294 receives a fault signal from the input / output controller 284 or the motor controller 290 and shunts a corresponding motor 292 (e.g., motor 302) in response to the fault signal. In some embodiments, the shunt component 294 is a hardware component (e.g., a circuit) that operates independently of the software or firmware of the system 279. In some embodiments, the motor controller 290 includes the shunt component 294.

[0109] It should be noted that, as used herein, the terms "couple," "coupled," "coupled," or other variations of the word coupled, may indicate either an indirect connection or a direct connection. For example, when a first component is "coupled" to a second component, the first component may be either indirectly connected to the second component through another component, or directly connected to the second component.

[0110] The term "computer-readable medium" refers to any available medium that can be accessed by a computer or processor. By way of example, and not limitation, such media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, compact disk read-only memory (CD-ROM), or other optical disk storage, magnetic disk storage, or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. It should be noted that computer-readable media may be tangible and non-transitory. As used herein, the term "code" may refer to software, instructions, code, or data that is executable by a computing device or processor.

[0111] The methods disclosed herein include one or more steps or acts for achieving the described method. The method steps and / or acts may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or acts is required for the proper operation of the described method, the order and / or use of specific steps and / or acts may be modified without departing from the scope of the claims.

[0112] As used herein, the term "plurality" refers to two or more. For example, a plurality of components refers to two or more components. The term "determining" covers a wide variety of acts, and thus "determining" can include calculating, computing, processing, deriving, investigating, looking up (e.g., consulting a table, database, or another data structure), ascertaining, and the like. Also, "determining" can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Also, "determining" can include resolving, selecting, electing, establishing, and the like.

[0113] The phrase "based on" does not mean "based only on," unless expressly specified otherwise. In other words, the phrase "based on" refers to both "based only on" and "based at least on."

[0114] The foregoing description of the disclosed implementations is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these implementations will be readily apparent to those skilled in the art, and the general principles set forth herein may be applied to other implementations without departing from the scope of the present invention. For example, those skilled in the art will recognize that many corresponding alternatives, equivalent structural details, such as similar manners of fastening, mounting, coupling, or engaging tool components, equivalent mechanisms for producing specific actuation motions, and equivalent mechanisms for delivering electrical energy, may be employed. Thus, the present invention is not intended to be limited to the implementations shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0115] 4. Examples of subject technology clauses. The following clauses describe several embodiments or implementations. Article 1. A health care system, A motor as a robot component; a driver circuit coupled to the motor; a shunt circuit coupled to the driver circuit and configured to shunt the driver circuit for a set amount of time to stop the motor, the shunt circuit comprising a capacitor (C) and a first resistor (R), the capacitor and the first resistor having an RC time constant, the set amount of time corresponding to the RC time constant; A medical system that has: Clause 2. The shunt circuit is a first switch coupled between the driver circuit and a voltage source; a second switch coupled between the driver circuit and electrical ground; a relay component coupled to a plurality of fault signal inputs, opening the first switch and closing the second switch in response to a fault signal at one of a plurality of fault signal inputs; a relay component configured to close the first switch and open the second switch a set amount of time after receiving a fault signal; 2. The medical system of claim 1, comprising: Clause 3. The medical system of clause 2, wherein the relay component includes a solid state relay. Clause 4. Multiple fault signal inputs emergency stop signal, A fault signal from the voltage source, or Fault signal from the driver circuit, The medical system according to claim 2 or 3, comprising at least one of the following: Clause 5. A medical system described in any one of clauses 2 to 4, wherein the shunt circuit comprises a second resistor coupled in series with the second switch. Clause 6. A medical system as described in any one of clauses 1 to 5, wherein the driver circuit comprises a set of diodes in parallel with the set of phase transistors, and the shunt circuit shunts the driver circuit by creating a path to electrical ground through the set of diodes. Clause 7. A medical system described in any one of clauses 1 to 6, wherein the robotic component comprises a robotic arm and the motor controls a joint of the robotic arm. Clause 8. The medical system of clause 7, wherein the robotic arm is capable of backdriving after a set amount of time. Clause 9. A medical system as described in any one of clauses 1 to 8, wherein the motor comprises a three-phase motor and the driver circuit comprises a set of transistors for each phase of the motor. Clause 10. A medical system as described in any one of clauses 1 to 9, wherein the medical system is configured to test the shunt circuit as part of the start-up process. Clause 11. A method for stopping a motor of a robotic component, comprising: Driving a motor via a driver circuit; receiving a fault signal while the motor is driven; shunting a driver circuit to stop the motor in response to a fault signal; disconnecting a driver circuit for the motor from a voltage source; and coupling the driver circuit to electrical ground via a resistor. The method of claim 1, further comprising shunting, wherein the driver circuit is decoupled from electrical ground according to charge draining from the capacitor. Article 12. Decoupling the driver circuit from the voltage source includes opening a first switch coupled between the driver circuit and the voltage source; 12. The method of claim 11, wherein coupling the driver circuit to electrical ground includes closing a second switch coupled between the driver circuit and the electrical ground. Clause 13. The method of clause 12, wherein shunting the driver circuit includes directing current from the motor to a resistor coupled in series with a second switch. Article 14. Fault signals: emergency stop signal, A fault signal from the voltage source, or Signals from the driver circuit, 14. The method according to any one of clauses 11 to 13, wherein the method is one of Clause 15. The method of any one of clauses 11-14, wherein the driver circuit comprises a set of diodes in parallel with the set of phase transistors, and shunting the driver circuit includes creating a path to electrical ground through the set of diodes. Clause 16. A method according to any one of clauses 11 to 15, wherein the motors control the joints of the robotic component, the method further comprising manipulating movement of the robotic component by adjusting operation of the motors. Clause 17. The method of any one of clauses 11 to 16, further comprising maintaining the driver circuit in a back-driveable state after disconnecting the driver circuit from electrical ground in accordance with charge draining from the capacitor, wherein in the back-driveable state the driver circuit is disconnected from the voltage source and from electrical ground. Clause 18. The method of any one of clauses 11 to 17, further comprising testing the shunt circuit as part of the start-up process of the robotic component. Article 19. A health system: A motor as a robot component; a driver circuit coupled to the motor; a shunt circuit coupled to the driver circuit and configured to shunt the driver circuit to stop the motor, a first switch coupling the driver circuit to a voltage source; a second switch coupling the driver circuit to electrical ground; a current sensor coupled to the driver circuit and configured to measure a current in the driver circuit; a control component coupled to the current sensor, the first switch, and the second switch, the control component being responsive to the fault signal to: A first switch is opened, and a shunt circuit comprising a control component configured to selectively open and close the second switch to maintain a current in the driver circuit within a set range while the motor is stopped; A medical system that has: Clause 20. A method for stopping a motor of a robotic component, comprising: Driving a motor via a driver circuit; receiving a fault signal while the motor is driven; shunting a driver circuit to stop the motor in response to a fault signal; Disconnecting the driver circuit for the motor from the voltage source; selectively coupling the driver circuit to electrical ground until the motor stops; monitoring a current in the driver circuit; disconnecting the driver circuit from electrical ground in accordance with the current exceeding a first predetermined threshold; and recoupling the driver circuit to electrical ground in accordance with the current falling below a second predetermined threshold; and selectively binding, and shunting. Article 21. A health system comprising: A motor as a robot component; a driver circuit coupled to the motor; a shunt circuit coupled to the driver circuit, a switch electrically coupled between the high voltage line of the driver circuit and electrical ground; a resistor electrically coupled between the high voltage line of the driver circuit and electrical ground; and a capacitor coupled to the switch for shunting the driver circuit for a set amount of time; a shunt circuit comprising: A medical system that has:

[0116] [Embodiment] (1) A health care system, comprising: A motor as a robot component; a driver circuit coupled to the motor; a shunt circuit coupled to the driver circuit and configured to shunt the driver circuit for a set amount of time to stop the motor, the shunt circuit comprising a capacitor (C) and a first resistor (R), the capacitor and the first resistor having an RC time constant, the set amount of time corresponding to the RC time constant; A medical system that has: (2) The shunt circuit comprises: a first switch coupled between the driver circuit and a voltage source; a second switch coupled between the driver circuit and electrical ground; a relay component coupled to a plurality of fault signal inputs, opening the first switch and closing the second switch in response to a fault signal on one of the plurality of fault signal inputs; a relay component configured to close the first switch and open the second switch after the set amount of time following receiving the fault signal; A medical system as described in embodiment 1, comprising: (3) The medical system of embodiment 2, wherein the relay component includes a solid-state relay. (4) The plurality of fault signal inputs include emergency stop signal, a fault signal from said voltage source, or a fault signal from the driver circuit; The medical system of embodiment 2, comprising at least one of the following: (5) The medical system of embodiment 2, wherein the shunt circuit comprises a second resistor coupled in series with the second switch.

[0117] (6) The medical system of embodiment 1, wherein the driver circuit comprises a set of diodes in parallel with a set of phase transistors, and the shunt circuit shunts the driver circuit by creating a path to electrical ground through the set of diodes. (7) The medical system of embodiment 1, wherein the robotic component comprises a robotic arm and the motor controls a joint of the robotic arm. (8) The medical system of claim 7, wherein the robotic arm is capable of backdriving after the set amount of time. (9) The medical system of embodiment 1, wherein the motor comprises a three-phase motor and the driver circuit comprises a set of transistors for each phase of the motor. (10) The medical system of embodiment 1, wherein the medical system is configured to test the shunt circuit as part of a start-up process.

[0118] (11) A method for stopping a motor of a robotic component, comprising: Driving the motor via a driver circuit; receiving a fault signal while the motor is driven; shunting the driver circuit to stop the motor in response to the fault signal; isolating the driver circuit for the motor from a voltage source; and and coupling the driver circuit to electrical ground through a resistor, the driver circuit being decoupled from the electrical ground according to charge draining from a capacitor. (12) Isolating the driver circuit from the voltage source includes opening a first switch coupled between the driver circuit and the voltage source; 12. The method of claim 11, wherein coupling the driver circuit to the electrical ground includes closing a second switch coupled between the driver circuit and the electrical ground. (13) The method of claim 12, wherein shunting the driver circuit includes directing current from the motor to the resistor coupled in series with the second switch. (14) The fault signal is emergency stop signal, a signal from the voltage source; or A signal from the driver circuit; 12. The method of embodiment 11, wherein the method is one of the following: (15) The method of embodiment 11, wherein the driver circuit comprises a set of diodes in parallel with a set of phase transistors, and shunting the driver circuit includes creating a path to the electrical ground through the set of diodes.

[0119] (16) The method of embodiment 11, wherein the motors control joints of the robotic component, the method further comprising manipulating movement of the robotic component by adjusting operation of the motors. (17) The method of claim 11, further comprising maintaining the driver circuit in a back-driveable state after decoupling the driver circuit from the electrical ground in accordance with the charge draining from the capacitor, wherein in the back-driveable state the driver circuit is decoupled from the voltage source and decoupled from the electrical ground. (18) The method of claim 11, further comprising testing the shunt circuit as part of a start-up process of the robotic component. (19) A health care system, comprising: A motor as a robot component; a driver circuit coupled to the motor; a shunt circuit coupled to the driver circuit and configured to shunt the driver circuit to stop the motor, the shunt circuit comprising: a first switch coupling the driver circuit to a voltage source; a second switch coupling the driver circuit to electrical ground; a current sensor coupled to the driver circuit and configured to measure a current in the driver circuit; and a control component coupled to the current sensor, the first switch, and the second switch, the control component being responsive to a fault signal; opening the first switch; and a shunt circuit comprising: a control component configured to selectively open and close the second switch to maintain the current in the driver circuit within a set range while stopping the motor; and A medical system that has: (20) A method for stopping a motor of a robotic component, comprising: Driving the motor via a driver circuit; receiving a fault signal while the motor is driven; shunting the driver circuit to stop the motor in response to the fault signal; isolating the driver circuit for the motor from a voltage source; selectively coupling the driver circuit to an electrical ground until the motor stops; monitoring a current in the driver circuit; disconnecting the driver circuit from the electrical ground in accordance with the current exceeding a first predetermined threshold; and recoupling the driver circuit to the electrical ground in accordance with the current falling below a second predetermined threshold; and selectively binding, and shunting, A method comprising:

[0120] (21) A health care system, comprising: A motor as a robot component; a driver circuit coupled to the motor; a shunt circuit coupled to the driver circuit, a switch electrically coupled between a high voltage line of the driver circuit and electrical ground; a resistor electrically coupled between the high voltage line of the driver circuit and the electrical ground; and a capacitor coupled to the switch for shunting the driver circuit for a set amount of time; a shunt circuit comprising: A medical system that has:

Claims

1. 1. A health care system comprising: A motor as a robot component; a driver circuit coupled to the motor; a shunt circuit coupled to the driver circuit and configured to shunt the driver circuit for a set amount of time to stop the motor, the shunt circuit comprising a capacitor (C) and a first resistor (R), the capacitor and the first resistor having an RC time constant, the set amount of time corresponding to the RC time constant; A medical system that has:

2. The shunt circuit includes: a first switch coupled between the driver circuit and a voltage source; a second switch coupled between the driver circuit and electrical ground; a relay component coupled to a plurality of fault signal inputs, opening the first switch and closing the second switch in response to a fault signal on one of the plurality of fault signal inputs; a relay component configured to: close the first switch and open the second switch after the set amount of time following receipt of the fault signal; The medical system of claim 1 .

3. The medical system of claim 2 , wherein the relay component comprises a solid state relay.

4. The plurality of fault signal inputs include: emergency stop signal, a fault signal from said voltage source, or a fault signal from the driver circuit; The medical system of claim 2 , comprising at least one of:

5. 3. The medical system of claim 2, wherein the shunt circuit comprises a second resistor coupled in series with the second switch.

6. 10. The medical system of claim 1, wherein the driver circuit comprises a set of diodes in parallel with a set of phase transistors, and the shunt circuit shunts the driver circuit by creating a path to electrical ground through the set of diodes.

7. The medical system of claim 1 , wherein the robotic component comprises a robotic arm and the motor controls a joint of the robotic arm.

8. The medical system of claim 7 , wherein the robotic arm is backdrivable after the set amount of time.

9. 10. The medical system of claim 1, wherein the motor comprises a three-phase motor and the driver circuit comprises a set of transistors for each phase of the motor.

10. The medical system of claim 1 , wherein the medical system is configured to test the shunt circuit as part of a start-up process.

11. 1. A method for stopping a motor of a robotic component, comprising: Driving the motor via a driver circuit; receiving a fault signal while the motor is driven; shunting the driver circuit to stop the motor in response to the fault signal; isolating the driver circuit for the motor from a voltage source; and and coupling the driver circuit to electrical ground through a resistor, the driver circuit being decoupled from the electrical ground according to charge draining from a capacitor.

12. decoupling the driver circuit from the voltage source includes opening a first switch coupled between the driver circuit and the voltage source; The method of claim 11 , wherein coupling the driver circuit to the electrical ground includes closing a second switch coupled between the driver circuit and the electrical ground.

13. The method of claim 12 , wherein shunting the driver circuit includes directing current from the motor to the resistor coupled in series with the second switch.

14. The fault signal is emergency stop signal, a signal from the voltage source; or A signal from the driver circuit; The method of claim 11, wherein the

15. 12. The method of claim 11, wherein the driver circuit comprises a set of diodes in parallel with a set of phase transistors, and shunting the driver circuit includes creating a path to the electrical ground through the set of diodes.

16. The method of claim 11 , wherein the motors control joints of the robotic component, the method further comprising manipulating movement of the robotic component by adjusting operation of the motors.

17. 12. The method of claim 11, further comprising: maintaining the driver circuit in a back-driveable state after decoupling the driver circuit from the electrical ground in accordance with the charge draining from the capacitor, wherein in the back-driveable state the driver circuit is decoupled from the voltage source and decoupled from the electrical ground.

18. The method of claim 11 , further comprising testing the shunt circuit as part of an activation process of the robotic component.

19. 1. A health care system comprising: A motor as a robot component; a driver circuit coupled to the motor; a shunt circuit coupled to the driver circuit and configured to shunt the driver circuit to stop the motor, the shunt circuit comprising: a first switch coupling the driver circuit to a voltage source; a second switch coupling the driver circuit to electrical ground; a current sensor coupled to the driver circuit and configured to measure a current in the driver circuit; and a control component coupled to the current sensor, the first switch, and the second switch, the control component being responsive to a fault signal; opening the first switch; and a control component configured to selectively open and close the second switch to maintain the current in the driver circuit within a set range while stopping the motor; and A medical system that has:

20. 1. A method for stopping a motor of a robotic component, comprising: Driving the motor via a driver circuit; receiving a fault signal while the motor is driven; shunting the driver circuit to stop the motor in response to the fault signal; isolating the driver circuit for the motor from a voltage source; selectively coupling the driver circuit to an electrical ground until the motor stops; monitoring a current in the driver circuit; disconnecting the driver circuit from the electrical ground in accordance with the current exceeding a first predetermined threshold; and recoupling the driver circuit to the electrical ground in accordance with the current falling below a second predetermined threshold; and selectively binding, and shunting, A method comprising:

21. 1. A health care system comprising: A motor as a robot component; a driver circuit coupled to the motor; a shunt circuit coupled to the driver circuit, a switch electrically coupled between a high voltage line of the driver circuit and electrical ground; a resistor electrically coupled between the high voltage line of the driver circuit and the electrical ground; and a capacitor coupled to the switch for shunting the driver circuit for a set amount of time; a shunt circuit comprising: A medical system that has:

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