Powering a surgical robot arm

Abstract

A control system for a surgical robotic system, the surgical robotic system comprising a remote surgeon console having a surgeon input device; and a surgical robotic arm comprising a series of joints extending from a base to a distal end for attachment to a surgical instrument, the surgical robotic arm being operable in a full power mode in which the joints of the surgical robotic arm are powered by a first power supply and a reduced power mode in which the joints of the surgical robotic arm are powered by a second power supply, the control system being configured to: control the surgical robotic arm in a surgical mode by translating movement of the surgeon input device into control signals for moving the joints of the surgical robotic arm when the surgical robotic arm is operated in the full power mode; detect a power failure of the first power supply; in response to detecting the power failure, enable the reduced power mode and transition control of the surgical robotic arm from the surgical mode to a standby mode; when in the reduced power mode, receive a command from a user input located on or adjacent to the surgical robotic arm or on the surgeon console; and in response to receiving the command, transition control of the surgical robotic arm from the standby mode to a calibration mode.

Description

Background Technology

[0001] The use of robots to assist and perform surgery is known. Figure 1 A typical surgical robot system is illustrated. The surgical robot 100 consists of a base 102, an arm 104, and an instrument 106. The base supports the robot and can be rigidly attached to, for example, the operating room floor, operating room ceiling, or a trolley. The arm extends between the base and the instrument. The arm is hinged by means of a plurality of flexible joints 108 along its length, which are used to position the surgical instrument relative to the patient in a desired location. The surgical instrument is attached to the distal end of the robotic arm. The surgical instrument penetrates the patient's body at its port to access the surgical site. The surgical instrument includes an axis that is articulated to a distal end effector 110 via joints. The end effector participates in the surgical procedure. Figure 1 In the diagram, the end effector is a pair of jaws. The surgeon controls the surgical robot 100 via a remote surgical console 112. The surgical console includes one or more surgical input devices 114. These can take the form of manual controllers or foot pedals. The surgical console also includes a display 116.

[0002] The control system 118 connects the surgeon's console 112 to the surgical robot 100. The control system receives input from the surgeon's input device and converts this input into control signals to move the joints of the robotic arm 104 and the end effector 110. The control system sends these control signals to the robot. The joint controllers on the robotic arm 104 drive the joints 108 to move accordingly.

[0003] Power for driving the joints of the robotic arm 104 is supplied to the robotic arm from the surgeon's console 112 via power cables. In the event of a power failure, it is known to use mechanical brakes to hold the joints of the robotic arm 104 in place and to manually remove the surgical instruments 106 from the patient. Summary of the Invention

[0004] A control system for a surgical robot system includes: a remote surgeon's console with a surgeon's input device; and a surgical robot arm including a series of joints extending from a base to an end for attachment to surgical instruments. The surgical robot arm can operate in a full-power mode and a reduced-power mode. In the full-power mode, the joints of the surgical robot arm are powered by a first power source, and in the reduced-power mode, the joints of the surgical robot arm are powered by a second power source. The control system is configured to: control the surgical robot arm in a surgical mode by converting movement of the surgeon's input device into control signals for moving the joints of the surgical robot arm when the surgical robot arm is operating in the full-power mode; detect a power failure of the first power source; enable the reduced-power mode in response to detecting the power failure, and switch control of the surgical robot arm from the surgical mode to a standby mode; receive commands from user input located on or near the surgical robot arm or located on the surgeon's console when in the reduced-power mode; and switch control of the surgical robot arm from the standby mode to a calibration mode in response to receiving the commands.

[0005] The control system may, in the calibration mode, not convert the movement of the surgeon's input device into control signals for moving the joints of the surgical robot arm.

[0006] The control system can, in the calibration mode,: detect external forces applied to the surgical robot arm; and send control signals to the surgical robot arm to move one or more joints of the surgical robot arm to match the detected external forces.

[0007] The control system can respond to receiving the command from the user input: determine whether there is a battery capacity greater than the threshold battery capacity available from the second power source; and switch the control of the surgical robot arm from the standby mode to the calibration mode only when it is determined that there is a battery capacity greater than the threshold battery capacity available from the second power source.

[0008] The control system can keep the surgical robot arm in the standby mode when it determines that there is a battery capacity less than the threshold available from the second power source.

[0009] The control system can respond to receiving the command from the user input: determine whether the surgical instrument is in the patient's body; and switch the control of the surgical robot arm from the standby mode to the calibration mode only when it is determined that the surgical instrument is not in the patient's body.

[0010] The control system can keep the surgical robotic arm in the standby mode when it determines that the surgical instruments are in the patient's body.

[0011] The surgical robot arm can be mounted on a support structure, and user input located on or near the surgical robot arm can be located on the support structure.

[0012] The control system may: when the surgical robot arm is operating in the full-power mode, control the surgical robot arm in another mode in which the control system constrains the movement of the surgical robot arm to maintain the intersection between the surgical instruments and the stored fulcrum; detect a power failure of the first power source; in response to detecting the power failure, enable the reduced-power mode and switch the control of the surgical robot arm from the other mode to the standby mode; when in the reduced-power mode, receive commands from user input located on or near the surgical robot arm; and in response to receiving the commands, switch the control of the surgical robot arm from the standby mode to the calibration mode.

[0013] The other mode may be an instrument adjustment mode, in which the control system controls the surgical robot arm to conform to the detected external force applied to the surgical robot arm.

[0014] The other mode can be an instrument replacement mode, in which the control system controls the surgical robot arm to align with the component of the external force detected and positioned along the longitudinal axis of the surgical instrument.

[0015] The other mode can be a locking mode, in which the control system holds the joints of the surgical robot arm in place against gravity.

[0016] The stored fulcrum can be the point around which the surgical instrument pivots when the configuration of the surgical robotic arm changes within the port of the surgical instrument in the patient's body.

[0017] The first power source can be a mains power source.

[0018] The mains power can be supplied to the surgical robot arm via the remote surgeon's console.

[0019] The second power source may include a battery.

[0020] The battery may be rechargeable.

[0021] The second power source may include another battery, wherein the other battery is non-rechargeable.

[0022] The control system may include a robot arm controller configured to detect power failures, restore power after a power failure, and enable and disable the full-power mode and the reduced-power mode. Attached Figure Description

[0023] The invention will now be described by way of example with reference to the accompanying drawings. In the drawings:

[0024] Figure 1 A surgical robot system for performing surgical procedures is shown;

[0025] Figure 2 The surgical robot arm is shown;

[0026] Figure 3 It shows Figure 2 An exploded view of the joints of a surgical robot arm;

[0027] Figure 4 A schematic diagram of the control system of the surgical robot system is shown;

[0028] Figure 5 The operating modes of the surgical robotic arm are shown, as well as the permissible transitions between these modes; and

[0029] Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 , Figure 11 and Figure 12 This is a flowchart illustrating the control method of the robot arm controller during a power failure. Detailed Implementation

[0030] The following describes Figure 1 The surgical robotic system shown is of the type described. This system includes one or more surgical robotic arms and surgical instruments, as well as a remote surgeon's console. The remote surgeon's console is connected to the surgical robotic arms via a control system. The control system includes a central controller positioned remotely to the surgical robotic arms. The control system may also include a robotic arm controller for each surgical robotic arm, which is co-positioned with the surgical robotic arm.

[0031] The control system and method described below are for a surgical robotic arm that holds surgical instruments, the instruments having an end effector at their distal end for manipulating the patient's tissues at the surgical site. The end effector can be, for example, a pair of jaws, a scalpel, a suture needle, etc. However, the same surgical robotic arm, control system, and method are equally applicable to surgical instruments for endoscopes, the endoscope having a camera at its distal end for capturing video feeds from the surgical site.

[0032] Figure 2 An exemplary surgical robot 200 is shown. The robot includes a base 201, which is fixed in place when a surgical procedure is being performed. The base 201 is suitably mounted to a support structure. Figure 2 In this design, the support structure is a trolley 210. This trolley can be a bedside trolley for mounting the robot at bed height. Alternatively, the support structure can be a device mounted on the ceiling or mounted on the bed.

[0033] A robotic arm 202 extends from the robot's base 201 to an end effector 203 for attachment to a surgical instrument 204. The arm is flexible. It is hinged by means of a plurality of flexible joints 205 along its length. Between the joints are rigid arm links 206. Appropriately, the joints are rotary joints. The robotic arm has at least seven joints between the base and the end effector. Figure 2 The robotic arm 200 shown has a total of eight joints between the base 201 and the end cap 203. Figure 2 The robotic arm shown has only eight joints between the base and the end effector. These joints include one or more roll joints (each having a rotational axis on either side of the joint along the longitudinal direction of the arm link), one or more pitch joints (each having a rotational axis transverse to the longitudinal direction of the preceding arm link), and one or more yaw joints (each also having a rotational axis transverse to the longitudinal direction of the preceding arm link and also transverse to the rotational axis of the co-located pitch joint). Figure 2 In the example, joints 205a, 205c, 205e, and 205h are rolling joints; joints 205b, 205d, and 205f are pitch joints; and joint 205g is a yaw joint. The order of the joints from the base 201 of the robot arm to the end effector 203 of the robot arm is: roll, pitch, roll, pitch, roll, pitch, yaw, roll. Figure 2 There are no intermediate joints in it.

[0034] Figure 3 It shows Figure 2The surgical robot arm has joints. The robot arm is hinged by eight joints. Roll joint J1 205a is adjacent to base 201, and subsequently to pitch joint J2 205b. Pitch joint J2 has a rotational axis perpendicular to the rotational axis of roll joint J1. Roll joint J3 205c is adjacent to pitch joint J2, and subsequently to pitch joint J4 205d. Pitch joint J4 has a rotational axis perpendicular to the rotational axis of roll joint J3. Roll joint J5 205e is adjacent to pitch joint J4, subsequently to pitch joint J6 205f and yaw joint J7 205g, and subsequently to roll joint J8 205h. Pitch joint J6 and yaw joint J7 form a compound joint, which may be a ball joint. Pitch joint J6 and yaw joint J7 have intersecting rotational axes.

[0035] The distal end of the robotic arm at the base can be hinged relative to the base by the movement of one or more joints of the arm. The rotation axes of a set of distal joints J5, J6, J7, and J8 intersect at a point on the surgical robotic arm. Refer to the wrist. Suitably, the wrist is a portion of the robotic arm rigidly coupled to the distal end of the instrument when it is attached to the robotic arm. The wrist has a position and orientation. For example, the position of the wrist can be the intersection of the rotation axes of J5, J6, J7, and J8. Alternatively, the position of the wrist can be the intersection of one or more rotation axes of a joint of the instrument. Alternatively, the position of the wrist can be the intersection of one or more rotation axes of a distal joint of the robotic arm with one or more rotation axes of a joint of the instrument. Figure 2 and Figure 3 The surgical robot arm shown has redundant joints. For a given wrist position relative to the base of the surgical robot arm, joints J1 to J4 have more than one configuration. Therefore, the surgical robot arm can adopt different postures while maintaining the same wrist position.

[0036] Surgical robotic arms can be combined with Figure 2 and Figure 3 The arms are joined differently as shown. For example, an arm may have fewer than eight or more than eight joints. An arm may include joints that allow movement other than rotation between corresponding sides of the joint, such as telescopic joints.

[0037] return Figure 2The surgical robotic arm includes a set of motors 207. Each motor 207 drives one or more joints 205. Each motor 207 is controlled by a joint controller. The joint controller can be co-located with the motor 207. The joint controller can control one or more of the motors 207. The robotic arm includes a series of sensors 208, 209. For each joint, these sensors include a position sensor 208 for sensing the position of the joint, and a torque sensor 209 for sensing the torque applied about the rotational axis of the joint. The torque applied about the rotational axis of the joint includes any or a combination of the following components: torque due to gravity acting on the joint, torque due to inertia, and torque due to external forces applied to the joint. One or both of the position sensor and the torque sensor for the joint can be integrated with the motor for that joint. The outputs of the sensors are transmitted to the control system.

[0038] Surgical instrument 204 is attached to a drive assembly at the end of robotic arm 203. This attachment point is always external to the patient. Surgical instrument 204 has an elongated profile with its central axis spanning between its proximal and distal ends, the proximal end of which is attached to the robotic arm, and the distal end approaching the surgical site within the patient's body. The surgical instrument can be configured to extend linearly parallel to the axis of rotation of joint 205h of the arm. For example, the surgical instrument can extend along an axis coinciding with the axis of rotation of joint 205h of the arm.

[0039] The proximal end and instrument shaft of the surgical instrument can be rigid relative to each other, and rigid relative to the distal end of the robotic arm when attached to it. An incision is made in the patient's body, through which a port is inserted. The surgical instrument can penetrate the patient's body through the port to access the surgical site. Alternatively, the surgical instrument can penetrate the body through natural cavities to access the surgical site. At the proximal end of the instrument, the shaft connects to an instrument interface. The instrument interface engages with a drive assembly at the distal end of the robotic arm. Specifically, each instrument interface element of the instrument interface engages with a corresponding drive assembly interface element of the drive assembly. The instrument interface can be releasably engaged with the drive assembly. The instrument can be manually detached from the robotic arm without any tools. This allows the instrument to be quickly detached from the drive assembly and attached to another instrument during operation.

[0040] At the distal end of the surgical instrument, the distal end of the instrument axis is connected to an end effector via a hinged connection. The end effector participates in the surgical procedure at the surgical site. The end effector can be, for example, a pair of jaws, a pair of single-pole scissors, a needle holder, a perforated gripper, or a scalpel. The hinged connection includes several joints. These joints allow the orientation of the end effector to be changed relative to the instrument axis. The end effector itself may also include joints. Figure 2 and Figure 3The end effector shown has a pair of opposing end effector elements 307, 308. The joints of the end effector are... Figure 3 The diagram above shows a pitch joint 301, a yaw joint 302, and a clamping joint 303. The pitch joint 301 is adjacent to the axis of the instrument and rotates about an axis perpendicular to the longitudinal axis of the instrument. The yaw joint 302 has an axis of rotation perpendicular to the axis of rotation of the pitch joint 301. The clamping joint 303 determines the deployment of the end effector element. In practice, the clamping joint 303 may be another yaw joint having the same axis of rotation as the yaw joint 302. Independent operation of the two yaw joints 302 and 303 can cause the end effector element to yaw uniformly and / or open and close relative to each other.

[0041] Driving force is transmitted from the robotic arm to the end effector in any suitable manner. For example, the joints of the instrument can be driven by drive elements such as cables, push rods, or push / pull rods. These drive elements engage the instrument interface at the proximal end of the instrument. The drive assembly at the end of the robotic arm includes instrument drive joints that transmit driving force from the surgical robotic arm to the instrument interface via the corresponding interface elements described above, and thereby to the instrument joints. These instrument drive joints in... Figure 3 The above shows joints J9 and J 10 and J 11 . Figure 3 Three instrument drive joints are shown, each of which drives one of the three joints of the instrument.

[0042] Appropriately, the instrument drive joint is the sole device for transmitting driving forces to the instrument joint. A robotic arm may have more or fewer than three instrument drive joints. Surgical instruments may have more or fewer than three joints. For example... Figure 3 As shown, a device-driven joint may have a one-to-one mapping with the device joint it drives. Alternatively, a device-driven joint may drive more than one device joint.

[0043] A surgeon's console is remotely positioned away from one or more surgical robotic arms of a surgical robotic system. The surgeon's console includes one or more surgeon input devices and a display. Each surgeon input device enables the surgeon to provide control input to the control system. For example, a surgeon input device can be a manual controller, a foot controller such as a pedal, a touch-sensitive input controlled by a finger or another part of the body, a voice-controlled input device, an eye-controlled input device, or a gesture-controlled input device. The surgeon input device can provide several inputs that the surgeon can operate independently.

[0044] For example, the surgeon's input device can be a manual controller connected to the surgeon's console, for instance, via a leveling device. This allows the manual controller to move with three translational degrees of freedom relative to the surgeon's console. Such movement can be used to command the corresponding movement of the end effector of the instrument. The manual controller can also rotate relative to the surgeon's console. Such movement can be used to command the corresponding rotation of the end effector of the instrument.

[0045] A surgeon's console may include two or more surgeon input devices. Each surgeon input device can be used to control different surgical instruments. Thus, for example, a surgeon can use a manual controller in their left hand to control one surgical instrument and a manual controller in their right hand to control another surgical instrument.

[0046] The control system connects the surgeon's console to one or more surgical robots. Figure 4 This control system is illustrated. A surgeon's console 401 is connected to a central controller 402 via a bidirectional communication link. Specifically, the surgeon's input device of the surgeon's console 401 is communicatively coupled to the central controller 402. The central controller 402 is connected via a bidirectional communication link to arm controllers 403, 404, and 405 of each surgical robot arm in the surgical robot system. Each arm controller is co-located with the surgical robot arm. The arm controller may be located within the surgical robot arm. Alternatively, the arm controller may be located in a support structure supporting the surgical robot arm, such as in a trolley for the arm. The central controller is remotely located away from at least one location within the surgical robot arm. Appropriately, the central controller is remotely located away from all surgical robot arm locations in the surgical robot system. The central controller may be located at the surgeon's console. Alternatively, the central controller may be co-located with one of the arm controllers. The central controller may be located remotely from the surgeon's console and all arm controllers.

[0047] The central controller includes a processor 406 and a memory 407. The memory 407 stores software code in a non-transitory manner, which can be executed by the processor 406 to enable the processor to control the surgeon's console and one or more surgical robotic arms and instruments in the manner described herein.

[0048] Each of the arm controllers includes a processor 408 and a memory 409. The memory 409 stores software code in a non-transitory manner, which can be executed by the processor 408 to enable the processor to control the surgeon's console and one or more surgical robotic arms and instruments in the manner described herein.

[0049] The central controller 402 receives commands from the surgeon's input device. The commands from the surgeon's input device indicate a desired change in position and / or orientation of the distal end of the surgical instrument. The control system converts the commands received from the surgeon's input device into drive signals. This conversion is performed by one or a combination of the central controller and the surgical robot arm controller associated with the surgeon's input device. The robot arm controller sends drive signals to the joint controllers of the surgical robot arm and / or the surgical instrument associated with the surgeon's input device. These joint controllers respond by correspondingly driving the joint motors. This drives the joints to cause the end effector to adopt the desired position and / or orientation commanded by the surgeon's input device. Thus, in response to the manipulation of the surgeon's input device, the control system controls the manipulation of the surgical instrument.

[0050] The control system receives input from position and torque sensors on the joints of the surgical robot arm. Using the known sequence of joints and links in the arm and the sensed joint positions, the control system determines the current configuration of the surgical robot arm. Based on the current configuration of the surgical robot arm and attached surgical instruments, and the known mass and dimensions of the links and joints of the robot arm and instruments, the control system determines the torque due to gravity acting on each joint. The control system sends gravity-compensated drive signals to the joint controllers of the robot arm. The joint controllers respond by driving the joint motors to counteract the gravity acting on each joint. In other words, the torque applied by each joint motor is exactly opposite to the calculated gravity acting on the joint. In the absence of commands from the surgeon's input device and / or external forces acting on the robot arm (other than gravity), the robot arm is thus held in place against gravity. It does not sag under gravity. In practice, each drive signal sent by the control system to the joint controllers to drive the joint motors can be interpreted as a component driving the joints based on the input received from the surgeon's input device and a component counteracting gravity. In some modes, as discussed below, the drive signal may also include a component that drives the joint to correspond with an external force applied to the robot arm.

[0051] Surgical robotic arms can operate in many different modes. Figure 5 Some exemplary operating modes of a surgical robotic arm are shown, along with the permissible transitions between these operating modes.

[0052] Figure 5Calibration mode 501 is illustrated. In calibration mode 501, the surgical robot arm is driven to conform to an external force applied to it. Specifically, torque sensor 209 detects the external force applied to the robot arm. The external force can be, for example, a bedside team member applying force to the robot arm by pushing it. As described above, the sensed torque about the axis of rotation of the joint includes any one or a combination of the following components: torque due to gravity acting on the joint, torque due to inertia, and torque due to the external force applied to the joint. The control system subtracts the torque due to gravity and inertia from the sensed torque about the joint to determine the component of the torque about the joint due to the external force. The control system then determines a drive signal to drive the joint to conform to the external force. The control system sends the drive signal to a joint controller that controls the joint. The joint controller controls the joint's motor to drive the joint as commanded by the control system. Thus, when an external force is applied to the joint, the joint is driven to conform to that force. Therefore, the robot arm complies with the force applied to it by the operator.

[0053] In calibration mode 501, the control system drives the robotic arm to counteract the gravitational torque acting on the robotic arm as described above. Therefore, in calibration mode 501, a member of the bedside team can manipulate the robotic arm into the desired position by pushing or pulling any part of the robotic arm, and that part will remain in that position regardless of the effects of gravity on it and any parts that depend on it.

[0054] In calibration mode 501, the control system does not convert detected manipulations of the surgeon's input device into drive signals for moving the joints of the robotic arm. Any input received by the control system from the surgeon's input device is not converted into movement of the robotic arm.

[0055] Calibration mode 501 is primarily used during the setup of the surgical robot system prior to the start of the operation. For example, surgical instruments can be attached to the robotic arm during calibration mode 501, and a member of the bedside staff can manipulate the robotic arm to insert the surgical instruments into ports in the patient's body along the desired direction to reach the surgical site. If the robotic arm and its support structure are moved or repositioned during the operation, calibration mode 501 is used again to manipulate the robotic arm into the appropriate position.

[0056] During the setup of the surgical robot system, a calibration mode is used to determine the virtual pivot point. The virtual pivot point is the natural center of rotation of an instrument with a rigid axis as it moves within the patient's body. Specifically, it is the fulcrum around which the surgical instrument pivots as the construction of the surgical robot arm changes within the port of the instrument in the patient's body. The port is inserted into the patient's abdominal wall. The port is approximately 2-10 cm long. The instrument is inserted into the patient's body through the port. The virtual pivot point lies along the length of the port. The exact location of the virtual pivot point depends on the patient's anatomy and therefore varies from patient to patient.

[0057] The virtual pivot point can be determined using the following method. When the instrument is in the port, the operator moves the distal end of the robot arm generally laterally to the instrument axis. This movement causes the port to exert a lateral force on the instrument axis as the instrument axis passes through the port, resulting in the instrument applying torque to the joints of the arm—in this case, joints J6 205f and J7 205g—the axes of which are laterally to the longitudinal axis of the instrument axis. The position of each arm joint is measured by its associated position sensor 208, and this sensed position is output to the control system. The torque at each arm joint is measured by its associated torque sensor 209, and this sensed torque is output to the control system. Thus, as the operator moves the distal end of the robot arm laterally, the control system receives sensed input indicating the position and force at the arm joints. This information allows the control system to estimate: (a) the position of the distal end of the robot relative to the fixed base, and (b) the vector of the instrument axis relative to the distal end of the robot. Since the instrument axis passes through the channel of the port, the channel of the port must lie on this vector. As the distal end of the robot arm is moved, the controller calculates multiple pairs of distal end positions and instrument axis vectors. These vectors converge from their respective distal positions to the location of a virtual pivot point in the port's channel. By collecting a series of these data pairs and then solving for the average position of the convergence of the instrument axis vectors, the control system determines the virtual pivot point relative to the base.

[0058] Once the virtual pivot point is determined in calibration mode 501, then for Figure 5 The remaining modes shown above set virtual pivot points. These virtual pivot points are stored by the control system. Figure 5 In each of the other modes shown, the surgical robot arm is always driven such that the longitudinal axis of the attached surgical instrument intersects a virtual pivot point (regardless of whether the instrument is actually attached to the robot arm). The longitudinal axis of the surgical instrument has a known relationship with the longitudinal axis of the end effector of the robot arm. For example, as... Figure 2 As shown, the longitudinal axis of the surgical instrument can coincide with the longitudinal axis of the end of the robotic arm.

[0059] From calibration mode, the surgical robot arm can transition to locked mode 502. In locked mode 502, the control system holds the surgical robot arm in a fixed position. This fixed position is the position the surgical robot arm was in when transitioning from calibration mode to locked mode 502. In locked mode, the control system drives the joints of the robot arm to compensate for gravity (as described above). Otherwise, the control system does not convert any manipulation of the surgeon's input device or external forces applied to the robot arm into drive signals for driving the joints of the robot arm.

[0060] From locked mode 502, the surgical robotic arm can transition to instrument adjustment mode 503. In instrument adjustment mode 503, the control system drives the surgical robotic arm to conform to external forces applied to the robotic arm (as described above regarding calibration mode), while maintaining the longitudinal axis of the surgical instrument's axis intersecting the virtual pivot point determined in calibration mode. Instrument adjustment mode 503 can be used to adjust the position of the instrument within the patient's body. For example, after setting the virtual pivot point in calibration mode, instrument adjustment mode 503 can be used to enable members of the bedside team to push the instrument into the patient's body, allowing the end effector to reach the surgical site. In instrument adjustment mode 503, the control system drives the joints of the robotic arm to compensate for gravity (as described above). In instrument adjustment mode 503, the control system does not translate any manipulation of the surgeon's input devices into drive signals for driving the joints of the robotic arm.

[0061] From instrument adjustment mode 503, the surgical robot arm can transition to surgical mode 504 or instrument changing mode 505. In surgical mode 504, the control system responds to the input by converting input received from the surgeon's input device into control signals (as described above) for controlling the movement of the surgical robot arm and / or the surgical instruments associated with the surgeon's input device. The end effector of the surgical instrument thus moves as commanded by the surgeon's input device. When performing the transition, the control system maintains the intersection of the longitudinal axis of the surgical instrument's axis with a virtual pivot point.

[0062] Surgical mode 504 may include a clutch mode. The clutch mode may be initiated by a surgeon's console, for example, via an input on a surgeon's input device. Alternatively, the clutch mode may be initiated by an input on the surgical robot arm or by a support to which the surgical robot arm is mounted. In clutch mode, manipulation of the surgeon's input device is temporarily disconnected from the robot arm. When an input indicating that the clutch mode is engaged is received, the control system does not translate manipulation of the surgeon's input device into control signals for driving the joints of the robot arm. The surgeon uses the clutch mode to move the surgeon's input device to a more comfortable position within the surgeon's input device's working area without transferring that movement to the end effector of the surgical instrument. The surgeon also uses the clutch mode to temporarily disengage a surgical instrument while focusing on a surgical instrument being manipulated by another surgeon's input device.

[0063] Surgical mode 504 can be a semi-compliant mode. In other words, the robotic arm can exhibit some compliant behavior in response to external forces applied to it. For example, in surgical mode 504, the control system can respond to a sensed external force applied near the elbow joint 205d by controlling motors driving the elbow joint 205d and surrounding joints of the arm to drive these joints to comply with the sensed external force. This allows bedside team members to push away the elbow joint 205d or a portion of the arm near it, enabling them to approach the patient during the surgical mode. To achieve this, the control system can define a permissible area or volume for one or more designated compliant portions of the robotic arm, such that movement of these portions in response to externally applied forces is limited to the permissible area / volume. The permissible area / volume is defined such that movement within that area / volume in response to externally applied forces does not affect the instrument's construction. The robotic arm is only semi-compliant in surgical mode 504 because the control system does not respond by conforming to external forces applied to any portion of the robotic arm other than those designated as compliant.

[0064] From surgical mode 504, the surgical robotic arm can transition to instrument adjustment mode 503 or instrument changing mode 505. Engaging instrument changing mode 505 allows for the removal of instruments from and / or insertion of instruments into the patient's body. In instrument changing mode 505, the control system drives the surgical robotic arm to align with the component of the external force sensed along the longitudinal axis of the surgical instrument toward or away from the surgical robotic arm. While in instrument changing mode 505, the control system keeps the longitudinal axis of the surgical instrument intersecting a virtual pivot point determined in calibration mode. The control system aligns with the sensed external force in the same manner as described above with respect to calibration mode, the only difference being that (i) the control system aligns only with the component of the force sensed in the specified direction (i.e., along the longitudinal axis of the surgical instrument toward or away from the surgical robotic arm), and (ii) the control system keeps the surgical instrument intersecting the virtual pivot point.

[0065] At the end of the procedure, when the surgical instruments are removed from the surgical site, or during the procedure when one instrument is replaced with another, members of the bedside team use instrument change mode 505 to allow them to remove the instrument from the patient's body and insert the new instrument. In instrument change mode 505, the control system prevents forces applied by members of the bedside team in any direction other than toward or away from the longitudinal axis of the surgical instrument relative to the robotic arm from being converted into corresponding movement of the robotic arm. Therefore, any lateral forces applied by members of the bedside team are not converted into corresponding movement of the robotic arm. This ensures that the removal of the surgical instrument is performed along the entry line between the port and the surgical site, thus avoiding damage to tissues remote from this line.

[0066] In instrument change mode 505, the control system limits the force applied by bedside team members along the longitudinal axis of the surgical instrument toward the patient's body to be translated into corresponding movement of the surgical robotic arm. This limitation prevents the end effector of the attached instrument from being pushed further into the patient's body than the end effector of the instrument was when entering instrument change mode. This limitation applies to the same instrument attached to the arm during instrument retrieval when entering instrument change mode. This limitation also applies to newly attached instruments inserted into the patient's body after instrument change. This ensures that surgical instruments cannot be pushed further into the patient's body, thereby causing damage to the surgical site.

[0067] In instrument changing mode 505, the control system drives the joints of the robotic arm to compensate for gravity (as described above). In instrument changing mode 505, the control system does not translate any manipulation of the surgeon's input device into drive signals for driving the joints of the robotic arm.

[0068] From instrument change mode 505, the surgical robot arm can switch to instrument adjustment mode 503 or surgical mode 504.

[0069] From each of the locking mode 502, instrument adjustment mode 503, surgical mode 504, and instrument change mode 505, the surgical robot arm can transition to a standby mode 506. From this standby mode 506, the surgical robot arm can transition back to one of its previously active locking mode, instrument adjustment mode, surgical mode, or instrument change mode. From standby mode 506, the surgical robot arm can also transition to calibration mode 501.

[0070] The surgical robotic arm or the support structure to which it is mounted may include one or more interfaces. These interfaces may be buttons or a set of buttons. These interfaces may be actuated, for example, by a member of the bedside team to control the operation of the surgical robotic arm. Figure 5 The description refers to the transitions between operating modes. The surgeon's console may include one or more interfaces that can, for example, be actuated by the surgeon to... Figure 5 The description refers to the transitions between different operating modes.

[0071] The surgical robotic arm requires electricity to power the joint motors that drive the joints and to power all the circuitry within the surgical robotic arm, including the robotic arm controller and joint controllers. The surgical robotic arm typically operates in full-power mode, in which it is powered by a mains power supply. This mains power supply is sufficient to maintain the surgical robotic arm's power needs throughout the entire surgical procedure. For example, the mains power supply could be a power line power supply. Power can be delivered from the mains power supply to the surgical robotic arm via the surgeon's console.

[0072] The surgical robotic arm can also operate in a reduced-power mode, in which it is powered by a secondary power source. In this reduced-power mode, fewer operating modes of the surgical robotic arm are available. (Reference) Figure 5 Locking mode 502, instrument adjustment mode 503, surgical mode 504, and instrument replacement mode 505 are only available in full-power mode. They are not available in reduced-power mode. Calibration mode 501 and standby mode 506 are both available in full-power mode and partially or fully available in reduced-power mode.

[0073] The secondary power supply may include one or more batteries. These batteries may be located locally at the surgical robotic arm. For example, each of the one or more batteries may be located in the surgical robotic arm itself, or in a support structure to which the surgical robotic arm is mounted. The secondary power supply may include two batteries. The first battery may be a rechargeable battery, and the second battery may be a non-rechargeable battery. The first battery, when fully charged, may provide sufficient electrical energy to drive the motors of the surgical robotic arm to maintain the position of the surgical robotic arm against gravity for at least N minutes. For example, 5<N<30. For example, N=5. The second battery may provide sufficient electrical energy to drive the motors of the surgical robotic arm (as described below) to maintain the surgical robotic arm for at least T seconds. For example, 20<T<180. For example, T=30. N and T are estimates of the time during which the batteries can provide the described electrical energy. These estimates may be based on a typical discharge versus time graph of the batteries, or a mathematical model of the ideal discharge of the batteries over time. The remaining battery life of each battery may be estimated by measuring the voltage, current or electrical energy output of the battery over time, and comparing these voltage / current / electrical energy readings with a typical battery life graph of voltage versus battery capacity. The maximum capacity of the first battery may be between 5000 and 6000 mAh. The maximum capacity of the second battery may be between 300 and 600 mAh.

[0074] The surgical robotic arm can only be energized for use when connected to the main power supply in the full power mode. The robotic arm controller on the surgical robotic arm detects that sufficient electrical energy is being received from the main power supply to power the functions of the surgical robotic arm. Upon detecting a power failure of the main power supply, the robotic arm controller switches the surgical robotic arm to a reduced power mode. In the reduced power mode, the robotic arm controller controls powering the surgical robotic arm from the secondary power supply. For example, initially in the reduced power mode, the robotic arm controller may control powering the surgical robotic arm from the first battery. If the first battery is exhausted, the robotic arm controller may control powering the surgical robotic arm from the second battery. The robotic arm controller may detect the power failure, detect power restoration after the power failure, and enable and disable the full power mode and the reduced power mode.

[0075] Referring now to Figures 6 to 12 A control method that may be executed by the control system in response to detecting a power failure of the surgical robotic arm is explained. Suitably, these control methods are executed by the robotic arm controller of the surgical robotic arm that has lost power.

[0076] From Figure 6Initially, at step 601, the surgical robot arm operates in full-power mode, where power is supplied by the mains power supply. At step 602, the control system operates the surgical robot arm in surgical mode. At step 603, the control system determines whether a power failure of the surgical robot arm has been detected. If no power failure is detected, the control system returns to step 602, where it continues to operate the surgical robot arm in surgical mode. If a power failure is detected at step 603, the control system responds by enabling a reduced-power mode at step 604 and entering standby mode at step 605. Standby mode is a locked mode in which the control system sends control signals to the joint controllers of the robot arm, commanding them to control the joint motors to drive the joints, thereby keeping the joints of the surgical robot arm locked in place. The control method then proceeds to step 606, where it determines whether full power has been restored, i.e., whether the power failure has stopped. If the answer is no, the control system holds the surgical robot arm in standby mode 605. If the answer is yes, the control system moves to step 607. At step 607, the control system responds to the detected power failure by disabling the reduced power mode and re-enabling the full power mode. The control system then returns to surgical mode 602.

[0077] Steps 604 and 605 can be pressed Figure 6 The steps can be performed in the order shown, or in reverse order, or simultaneously. Step 607 can be performed simultaneously with returning to surgical mode 602.

[0078] Although the surgical modality was described, Figure 6 The method is applicable to... Figure 5 The description includes any operating modes of the surgical robotic arm, namely, locking mode, instrument adjustment mode, and instrument changing mode.

[0079] Figure 6 This control method can be used for surgical robotic arms that are electrically braked instead of mechanically braked. In the event of a mains power failure, Figure 6 The control method ensures that the surgical robotic arm remains locked in its current position in standby mode. This prevents the robotic arm from sagging under gravity, which would otherwise occur if the robotic arm is not powered to counteract the gravitational torque acting on its joints. By keeping the robotic arm in a suitable position with backup battery power, time is provided to restore the robotic arm to full power or to safely remove surgical instruments attached to the robotic arm from the patient's body.

[0080] Figure 6The control methods facilitate the setup of the operating room for the procedure and its dismantling afterward. Typically, several surgical robotic arms and other equipment need to be properly positioned around the patient's bedside and set up before the surgical procedure begins. Figure 6 The control method allows the power cable of the surgical robot arm to be intentionally disconnected so that other equipment can roll over the robot arm without having to roll over the power cable. The power cable can then be re-inserted, and the surgical robot arm returns to its previous operating mode without requiring any recalibration procedures. During the time the power cable is disconnected, the robot arm remains in place. Figure 6 The control method can also be used during surgery to allow other components to roll through the path of the power cable attached to the surgical robot arm.

[0081] To enable the surgical robot arm to return to surgical mode upon restoration of full power, the control system stores a virtual pivot point determined during calibration mode. This virtual pivot point continues to be stored by the control system during reduced power mode. Upon returning to surgical mode after a power failure, the virtual pivot point is retrieved from memory by the control system and used to determine the drive signals sent to the joint controllers to drive the joint motors of the robot arm. This eliminates the need for recalibration after a power failure. To avoid recalibration, the support structure of the surgical robot arm must remain fixed during standby mode. If the support structure moves, for example by releasing and then re-braking the trolley to which the robot arm is mounted, the virtual pivot point will change. Therefore, the stored virtual pivot point will no longer be valid after full power is restored to the surgical robot arm.

[0082] Figure 7 It shows the Figure 6 Modification of the control method. Steps 601 to 606 and Figure 6The same applies. After detecting that full power has been restored at step 606, the control system proceeds to step 701. At step 701, the control system determines whether there is a battery capacity exceeding a threshold available from the secondary power source. For example, the control system may determine whether there is more than P seconds of power available from the secondary power source. If there is a battery capacity exceeding the threshold available from the secondary power source, the control system proceeds to step 607, where the control system disables the reduced power mode and re-enables the full power mode. From step 607, the control system returns to the surgical mode at step 602. If there is a battery capacity less than the threshold available from the secondary power source, the control system returns to the standby mode at step 605. If there is a battery capacity less than the threshold available from the secondary power source, the control system may issue an alarm at step 702. The control system may output an alarm signal as an indicator on the surgical robot arm. For example, an audio alarm signal output from a speaker on the robot arm and / or a visual indicator such as a flashing light on the robot arm. The control system may also send an alarm signal to the console of a remote surgeon. This alarm signal can be output as an audio alarm signal from the speaker on the control panel or as a visual indicator on the surgeon's control panel display.

[0083] Figure 7 The control method introduces excess Figure 6 Additional safety elements for the control method. Specifically, Figure 7 The control method ensures that, upon restoration of full power, there is still sufficient battery power to hold the surgical robot arm in place for at least P seconds before allowing it to return to surgical mode. Therefore, if full power is lost again, the surgical robot arm will use power from the battery to hold in place long enough for the bedside team to remove the instruments from the patient's body.

[0084] In the case where the secondary power source, as described above, includes a first rechargeable battery and a second non-rechargeable battery, P can be the same as T. In this case... Figure 7 Step 701 determines whether the first rechargeable battery is fully discharged and whether the second non-rechargeable battery has been depleted to less than T seconds of remaining energy to hold the surgical robotic arm. If so, the only available battery energy is the remaining energy of the second non-rechargeable battery, which, if less than T seconds, is considered insufficient to safely remove the surgical instruments from the patient's body. If more than T seconds of energy remains, the second non-rechargeable battery and / or the first rechargeable battery have sufficient available energy to allow the bedside team to safely remove the surgical instruments in the event of another power failure of the main power supply.

[0085] Figure 8 The surgical robotic arm is shown entering as referenced. Figure 6The control method for standby mode 605 described in steps 601 to 605. At step 801, after entering standby mode, the control system determines whether a command to change to calibration mode has been received from user input. User input can be an interface located on or near the surgical robot arm. For example, the interface can be located on the surgical robot arm or its support structure. User input can also be an interface located on the surgeon's console. In either case, the interface can take the form of a button, switch, slider, touch-sensitive input, voice control input, eye control input, or gesture control input.

[0086] If, at step 801, the control system determines that no user input has been received, the control system returns to standby mode at step 605. If, at step 801, the control system determines that user input has been received, the control method proceeds to step 802. At step 802, the control system responds to the command from the user input by switching the control of the surgical robot arm from standby mode to calibration mode.

[0087] Figure 8 This method allows the bedside team or surgeon to safely terminate a portion of the surgical robotic arm procedure in the event of a mains power failure. Upon receiving user input, the control system shifts the robotic arm to a calibrated mode that drives it in accordance with external forces applied to it. Therefore, the bedside team can remove the robotic arm and its support structure from the patient's bed.

[0088] Figure 9 It shows the Figure 8 Modification of the control method. Steps 601 to 801 and Figure 8 The same applies. At step 801, after detecting that a command to change to calibration mode has been received from user input, the control method proceeds to step 901. At step 901, the control system determines whether there is a battery capacity exceeding a threshold available from the secondary power source. For example, the control system may determine whether there is more than P seconds of electrical energy available from the secondary power source. If there is more than the threshold available from the secondary power source, the control method proceeds to step 902. At step 902, the control system switches control of the surgical robot arm from standby mode to calibration mode. If at step 901, the control system determines that there is less than the threshold available from the secondary power source, the control method returns to standby mode at step 605 or proceeds to step 903, in which the instrument is manually removed. If there is less than the threshold available from the secondary power source, the control system may issue an alarm at step 904. The control system may output an alarm signal as referenced above. Figure 7 The surgical robot arm has an indicator. The control system can also send alarm signals to the remote surgeon's console, as referenced above. Figure 7As described above, in the case where the secondary power source includes a first rechargeable battery and a second non-rechargeable battery, P may be the same as T.

[0089] At step 903, the bedside team can manually remove the instrument by detaching it from the robotic arm, manually opening the instrument's jaws to release any tissue gripped therein, manually straightening the instrument by manipulating the instrument interface elements, and then pulling the instrument away from the patient. No tools are required to perform this function.

[0090] Figure 10 It shows the Figure 8 Modification of the control method. Steps 601 to 801 and Figure 8 The same applies. At step 801, after detecting that a command to change to calibration mode has been received from user input, the control method proceeds to step 1001. At step 1001, the control system determines whether there is a surgical instrument attached to the surgical robot arm within the patient's body. This condition is not satisfied if: (i) there is no surgical instrument attached to the surgical robot arm, or (ii) there is a surgical instrument attached to the surgical robot arm, but the surgical instrument is not inserted into a port within the patient's body. If the control system determines that there is no surgical instrument attached to the surgical robot arm within the patient's body, then at step 1002, the control system transitions from standby mode to calibration mode. If at step 1001, the control system determines that there is a surgical instrument attached to the surgical robot arm within the patient's body, then the control method moves to (i) step 605, in which the control system holds the surgical robot arm in standby mode, or (ii) step 1003, in which the instrument is manually removed.

[0091] Figure 11 It shows the Figure 8 Modifications to the control methods, including... Figure 9 and Figure 10 Modify both. Steps 601 to 901 and Figure 9 The same applies. If, at step 901, the control system determines that less than a threshold battery capacity is available from the second power source, the control system (i) maintains the surgical robot arm in standby mode 605, or (ii) manually removes the instrument at step 1103. In either case, an alarm may be issued at step 903.

[0092] However, if at step 901 the control system determines that more than a threshold battery capacity can be obtained from the second power source, the control system moves to step 1101. At step 1101, the control system determines whether there is a surgical instrument attached to the surgical robot arm within the patient's body. If the control system determines that there is no surgical instrument attached to the surgical robot arm within the patient's body, then at step 1102, the control system transitions from standby mode to calibration mode. If at step 1101 the control system determines that there is a surgical instrument attached to the surgical robot arm within the patient's body, then at step 1103, the control system (i) maintains the surgical robot arm in standby mode at step 605, or (ii) manually removes the instrument at step 1103.

[0093] Steps 901 and 1101 can be pressed Figure 11 The order shown may be implemented, or the reverse order may be implemented, or they may be implemented simultaneously.

[0094] and Figure 6 Similarly, although the surgical model was described Figure 7 , Figure 8 , Figure 9 , Figure 10 and Figure 11 The methods, but they also apply to... Figure 5 The description includes any operating modes of the surgical robotic arm, namely, the locking mode, the instrument adjustment mode, and the instrument changing mode. These modes all share a common feature: when the surgical robotic arm is in this mode, the control system restricts the movement of the surgical robotic arm in order to maintain the intersection between the longitudinal axis of the surgical instrument axis and the virtual pivot point.

[0095] In the event of a power failure, the battery powering the surgical robot arm may be completely depleted, causing the robot arm controller to put the surgical robot arm into a minimum power mode, in which power is used only to maintain the position of the surgical robot arm in order to prevent surgical instruments from being further advanced into the patient's body.

[0096] A surgical robotic arm can be considered as consisting of three sets of joints. Each set of joints includes one or more joints. These three sets of joints will now be described.

[0097] For each joint in the first set of joints, when the base is located on a horizontal surface, the surgical robotic arm has a configuration such that each said joint: (i) is subjected to a gravitational torque or force, and (ii) movement of the joint in compliance with the gravitational torque or force will advance the surgical instrument attached to the surgical robotic arm into the patient's body towards the surgical site. To satisfy this definition, the surgical robotic arm only needs one configuration in which the joint satisfies both the first condition and the second condition. It is possible that for some other configurations of the surgical robotic arm, the same joint does not satisfy the first condition and the second condition. The joints of a particular surgical robotic arm that satisfy this definition depend on the specific structure of the surgical robotic arm including the joint sequence of the surgical robotic arm.

[0098] Movement of the joints in the first set of joints in compliance with the gravitational torque or force may advance the surgical instrument through the port into the patient's body by more than a threshold distance K. For example, the threshold distance K may be in the range of 0.1 cm < K < 5 cm. K may be in the range of 1 cm < K < 3 cm. K may be 2 cm.

[0099] For Figure 2 and Figure 3 of the surgical robotic arm, the first set of joints consists of a pitch joint J2 205b, a roll joint J3 205c and a pitch joint J4 205d. Each of these joints can move under the action of gravity, and thus advance the instrument into the patient's body. J2 is a pitch joint having a horizontal axis of rotation when the base of the surgical robotic arm is on a horizontal surface. Accordingly, gravity causes J2 to rotate about its axis. J3 is a roll joint having an axis of rotation along the J2-J4 arm link. The orientation of the J2-J4 arm link varies with the pose of the surgical robotic arm. If the J2-J4 arm link is vertical, J3 will not be subjected to gravitational torque. However, if the J2-J4 arm link is positioned along any non-vertical direction, J3 is subjected to a torque under the action of gravity. J4 is a pitch joint whose axis of rotation varies with the pose of the robotic arm. Unless the robotic arm is in a fully folded position, the weight of the robotic arm from J4 to the distal end exerts a force on J4 under the action of gravity.

[0100] For each joint in the second set of joints, when the base is located on a horizontal surface, the surgical robotic arm does not have a configuration that causes each said joint to be subjected to a gravitational torque or force. The joints of a particular surgical robotic arm that satisfy this definition depend on the specific structure of the surgical robotic arm including the joint sequence of the surgical robotic arm.

[0101] For Figure 2 and Figure 3of the surgical robot arm, the second set of joints is adjacent to the base of the surgical robot arm. The second set of joints is between the base and the first set of joints. The second set of joints consists of a rolling joint J1 205a. When the base of the surgical robot arm is on a horizontal surface, this rolling joint has a vertical axis of rotation. Therefore, this rolling joint will not move around its axis under the action of gravity.

[0102] For each joint in the third set of joints, when the base is located on a horizontal surface, the surgical robot arm does not have a configuration that allows the movement of each joint only under the action of gravity to advance the surgical instrument attached to the surgical robot arm through the port toward the surgical site in the patient's body. The joints of a particular surgical robot arm that satisfy this definition depend on the specific structure of the surgical robot arm including the joint sequence of the surgical robot arm.

[0103] The movement of the joints in the third set of joints only under the action of gravity can substantially not advance the instrument into the patient's body. The movement of the joints in the third set of joints only under the action of gravity can prevent the instrument from entering the patient's body significantly. The movement of the joints in the third set of joints that complies with gravitational torque or force can advance the surgical instrument into the patient's body by less than a threshold distance L. For example, the threshold distance L may be in the range of 0cm<L<2cm. L may be in the range of 0cm<L<0.2cm. L may be 2cm.

[0104] The port or the patient's abdomen can partially support the weight of the instrument, thereby preventing the instrument from being further inserted into the patient's body due to the movement of the joints in the third set of joints only under the action of gravity. Due to the movement of one joint in the third set of joints only under the action of gravity, the instrument may not move further into the patient's body beyond the distance allowed by the elasticity of the patient's abdomen.

[0105] For Figure 2 and Figure 3The third set of joints in the surgical robot arm is a series of joints adjacent to the end of the surgical robot arm. The third set of joints lies between the end of the surgical robot arm and the first set of joints. The third set of joints consists of a rolling joint J5 205e, a pitch joint J6 205f, a yaw joint J7 205g, and a rolling joint J8 205h. J5 is a rolling joint with a rotational axis along the J4-J6 / J7 arm link. Therefore, J5 only facilitates wrist rotation. Movement of J5 does not allow the instrument to be further inserted into the patient's body. The weight of the robot arm from J5 to the end of the arm does not exert torque on joint J5. J6 and J7 have consistent and perpendicular rotational axes consistent with the definition of wrist position (see above). Movement of J6 or J7 does not allow the instrument to be further inserted into the patient's body. The weight of the wrist does not exert torque on either joint J6 or J7. J8 is a rolling joint with a rotational axis along the longitudinal axis of the instrument's axis. Rotation of J8 about its axis does not allow the instrument to be further inserted into the patient's body. The weight of the wrist does not exert torque on J8.

[0106] Figure 12 A method executed by a robot arm controller is illustrated. At step 1201, the robot arm controller detects a power loss. The power loss can be detected in any suitable manner, such as those described above. As another example, a power loss can be detected by using sensors to detect the physical connection between the power cable and the robot arm or its support structure. A power loss is detected when a lack of physical connection in the power cable is detected. In response, at step 1202, the robot arm controller drives the first set of joints to maintain the position of each joint in the first set against gravity. The robot arm controller only drives the first set of joints to maintain their position against gravity. The robot arm controller does not drive the second or third set of joints to maintain their position against gravity. More specifically, the robot arm controller sends control signals to the joint controllers of the first set of joints to electrically brake the first set of joints. The joint controllers respond to the control signals from the robot arm controller by controlling the joint motors of the joints in the first set of joints to brake each joint in the first set of joints, and thereby maintain the position of each joint against gravity. The robot arm controller does not send control signals to the joint controllers of the second and third sets of joints to command them to electrically brake the second and third sets of joints.

[0107] Appropriately, Figure 12 The control method is implemented in the event of an impending total power failure. The robot arm controller responds to this situation by minimizing power consumption by only actively driving these joints of the surgical robot arm to resist gravity and maintain its position (which is critical from a safety perspective), as referenced. Figure 12as described. A safety-critical joint is a joint that: (i) would move under the effect of gravity if not held in place by an electric brake, and (ii) such movement under gravity could cause the instrument to advance further into the patient's body. When not actively driven to resist gravity and maintain their positions, other joints may allow the surgical instrument to rotate within the patient's body, but do not cause the surgical instrument to advance further into the patient's body, so they are not safety-critical joints.

[0108] In the surgical robotic arm described with reference Figure 2 and Figure 3 , in at least some configurations of the surgical robotic arm when the base of the surgical robotic arm is on a horizontal surface, joints J2, J3 and J4 sag under the effect of gravity, and this sagging can cause the instrument attached to the surgical robotic arm to advance further into the patient's body. Therefore, in this example, joints J2, J3 and J4 are safety-critical joints, which are electrically braked to maintain their positions against gravity in Figure 12 step 1202. In addition to preventing the instrument from moving further into the patient's body, electrically braking joints J2, J3 and J4 also prevents the wrist of the surgical robotic arm from moving under the effect of gravity. This prevents the instrument from pivoting about a virtual pivot point, and pivoting about the virtual pivot point may cause the instrument to move within the patient's body.

[0109] By applying only minimal power to the surgical robotic arm to prevent the surgical instrument from advancing further into the patient's body, the remaining battery life is extended as much as possible. Figure 12 step 1202 can enable the safety-critical joints to be electrically braked for at least R seconds. For example, 30 seconds < R < 120 seconds. R may be, for example, 60 seconds. During this period, the bedside team can take action to safely remove the surgical instrument from the patient's body.

[0110] In Figure 12 step 1201, the power loss level at which the robotic arm controller is triggered to detect power loss is implementation-specific. For example, the robotic arm controller may be configured to detect power loss if it determines that the remaining battery life of the second power supply has fallen below a threshold W. This threshold W may be in the range of 30 seconds < W < 5 minutes. This threshold W may be in the range of 60 seconds < W < 2 minutes. W may be 60 seconds.

[0111] As another example, the robotic arm controller may be configured to detect power loss if it determines that the remaining electrical energy capacity of the second power supply has fallen below a threshold electrical energy capacity.

[0112] As another example, the robotic arm controller may be configured to detect loss of power if it determines that the voltage or current supplied by the second power supply drops below a threshold V. For example, V may be in the range of 6V<V<11V.

[0113] As another example, if the secondary power supply comprises a first battery and a second battery, the robotic arm controller may be configured to detect loss of power upon determining that the first battery is depleted. The robotic arm controller may detect that the first battery is depleted when the voltage or current supplied by the first battery drops below a threshold U. For example, U may be in the range of 8V<U<15V. The robotic arm controller may comprise a watchdog circuit that monitors the state of the power supply of the surgical robotic arm. Suitably, the robotic arm controller receives power input from each of the main power supply, the first battery and the second battery. The robotic arm controller controls which power supply supplies power to the surgical robotic arm. Upon detecting loss of power from the first battery, the robotic arm controller switches from connecting the power input of the first battery to the surgical robotic arm to connecting the power input of the second battery to the surgical robotic arm. The robotic arm controller may also prevent communication between the processor of the robotic arm controller and the rest of the surgical robotic arm. For example, the robotic arm controller may prevent sending communications that command the joint controller to move the joints of the surgical robotic arm in accordance with movement of the surgeon input device. The robotic arm controller places the surgical robotic arm into a fault lock state, in which drive signals are maintained to the joint controllers to drive only critical joints to drive these critical joints against gravity. If the second battery is a non-rechargeable battery, then in step 1201, the second battery may need to be replaced after use to hold the robotic arm against gravity.

[0114] The robotic arm controller may be configured to detect loss of power only at Figure 12 step 1201 of

[0115] Once the robotic arm controller has implemented Figure 12 the control method, the robotic arm controller may be configured not to transition the surgical robotic arm to any of the operating modes in Figure 5 . Instead, the surgical robotic arm is powered down for maintenance before being used again.

[0116] The robots described herein may be used for purposes other than surgery. For example, the port may be an inspection port in a manufactured article such as an automobile engine, and the robot may control the viewing tool to view the interior of the engine.

[0117] The applicant hereby independently discloses each individual feature described herein, as well as any combination of two or more such features, provided that such features or combinations can be implemented based on this specification as a whole according to common general knowledge of those skilled in the art, regardless of whether such features or combinations of features solve any problem disclosed herein, and without limiting the scope of the claims. The applicant notes that aspects of the invention can consist of any such individual feature or combination of features. In view of the foregoing description, it will be apparent to those skilled in the art that various modifications can be made within the scope of the invention.

Claims

1. A control system for a surgical robot system, the surgical robot system comprising: A remote surgical console with a surgical input device; A surgical robotic arm, comprising a series of joints extending from a base to an end for attachment to surgical instruments, the surgical robotic arm being operable in a full-power mode and a reduced-power mode, wherein in the full-power mode the joints of the surgical robotic arm are powered by a first power source, and in the reduced-power mode the joints of the surgical robotic arm are powered by a second power source, the control system being configured to: When the surgical robot arm operates in the full-power mode, the surgical robot arm is controlled in surgical mode by converting the movement of the surgeon's input device into control signals for moving the joints of the surgical robot arm; Detect power supply failures in the first power source; In response to the detection of the power failure, the reduced power mode is activated, and the control of the surgical robot arm is switched from the surgical mode to the standby mode. When in the reduced power mode, commands are received from user input located on or near the surgical robot arm or on the surgeon's console. as well as In response to receiving the command, the control of the surgical robot arm is switched from the standby mode to the calibration mode.

2. The control system of claim 1, configured to not convert movement of the surgeon's input device into control signals for moving the joints of the surgical robot arm in the calibration mode.

3. The control system according to claim 1 or 2, configured in the calibration mode: Detecting the external force applied to the surgical robot arm; and Control signals are sent to the surgical robot arm to move one or more joints of the surgical robot arm in accordance with the detected external force.

4. The control system according to claim 1 or 2, configured to respond to receiving the command from the user input: Determine whether there exists a battery capacity greater than the threshold capacity obtainable from the second power source; and Control of the surgical robot arm is switched from the standby mode to the calibration mode only when it is determined that there is a battery capacity greater than the threshold available from the second power source.

5. The control system of claim 4, configured to maintain the surgical robot arm in the standby mode when it is determined that there is a battery capacity less than a threshold available from the second power source.

6. The control system according to claim 1 or 2, configured to respond to receiving the command from the user input: Determine whether the surgical instruments are located inside the patient's body; and Control of the surgical robotic arm is switched from the standby mode to the calibration mode only when it is determined that the surgical instruments are not located in the patient's body.

7. The control system of claim 6, configured to maintain the surgical robotic arm in the standby mode when it is determined that the surgical instruments are located in the patient's body.

8. The control system according to claim 1 or 2, wherein the surgical robot arm is mounted on a support structure, and the user input located on or adjacent to the surgical robot arm is located on the support structure.

9. The control system according to claim 1 or 2, wherein it is configured to: When the surgical robot arm operates in the full-power mode, the surgical robot arm is controlled in another mode in which the control system constrains the movement of the surgical robot arm in order to maintain the intersection between the surgical instrument and the stored fulcrum. Detect power supply failures in the first power source; In response to the detection of the power failure, the reduced power mode is activated, and the control of the surgical robot arm is switched from the other mode to the standby mode; When in the reduced power mode, commands are received from user input located on or near the surgical robot arm; as well as In response to receiving the command, the control of the surgical robot arm is switched from the standby mode to the calibration mode.

10. The control system of claim 9, wherein the other mode is an instrument adjustment mode, in which the control system is configured to control the surgical robot arm to conform to a detected external force applied to the surgical robot arm.

11. The control system of claim 9, wherein the other mode is an instrument changing mode, in which the control system is configured to control the surgical robot arm to conform to the component of a detected external force positioned along the longitudinal axis of the surgical instrument.

12. The control system of claim 9, wherein the other mode is a locking mode, in which the control system is configured to hold the joints of the surgical robot arm in place against gravity.

13. The control system of claim 9, wherein the stored pivot point is the point around which the surgical instrument pivots when the configuration of the surgical robot arm changes within the port of the surgical instrument in the patient's body.

14. The control system according to claim 1 or 2, wherein the first power source is a mains power source.

15. The control system of claim 14, wherein the mains power is provided to the surgical robot arm via the remote surgeon's console.

16. The control system according to claim 1 or 2, wherein the second power source comprises a battery.

17. The control system of claim 16, wherein the battery is rechargeable.

18. The control system of claim 16, wherein the second power source comprises another battery, wherein the other battery is non-rechargeable.

19. The control system of claim 1 or 2, wherein the control system includes a robot arm controller configured to detect a power failure, restore power after detecting a power failure, and enable and disable the full power mode and the reduced power mode.

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