Patent Description:
Teleoperated or computer assisted medical systems often employ a master control that a physician or other medical personnel can use to control actuated slave medical instruments. A medical instrument may, for example, include a tool such as a scalpel, forceps, or a cauterizing tool, and a surgeon may operate a master control similar to a joystick to provide control signals to a control system. The control system can then convert the control signals into actuation signals that drive actuators to move the instrument, for example, to cut, clamp, or cauterize a patient's tissue so that the tool movement follows the master control movement. One potential concern for such systems is inadvertent or uncontrolled movement of the master control, because a patient could be injured if uncontrolled movement of the master control causes uncontrolled operation of the tool that interacts with a patient's tissue. Surgeons can be trained to avoid situations where uncontrolled movement is possible, but additional techniques or fail safes may be desirable to prevent uncontrolled movement.

One way to reduce the chance of uncontrolled movement of the master control is to restrict movement of the mechanical components of the master control. For example, a master control may be balanced or actively driven so that gravity does not cause the master control to drift away from any position in which a physician may leave the master control. Other ways to reduce the chance of uncontrolled movement of an instrument may use a "locked" mode that decouples the master control from the instrument, so that in the locked mode, movement of the master control does not cause corresponding movement of the instrument. The locked mode might be automatically activated when a physician is not in the proper position for use of the master control. In particular, the system may default to the locked mode unless sensors detect that a physician is in the proper position for use of the system including, for example, being in position to view any movement of an end effector of the medical instrument. However, after a physician has taken a medical system out of the locked mode, the physician might release a master control while remaining in position to use the medical instrument. Releasing the master control under such circumstances may create the risk of the master control moving without physician input, resulting in uncontrolled motion of the medical instrument. For example, gravity compensation in the master control may be imperfect, or a physician's knee or hand may accidentally bump the master control while the physician is in position to use the instrument and the instrument is not in the locked mode.

<CIT> discloses a minimally invasive surgical system, in which a hand tracking system tracks a location of a sensor element mounted on part of a human hand. A system control parameter is generated based on the location of the part of the human hand. Operation of the minimally invasive surgical system is controlled using the system control parameter. Thus, the minimally invasive surgical system includes a hand tracking system. The hand tracking system tracks a location of part of a human hand. A controller coupled to the hand tracking system converts the location to a system control parameter, and injects into the minimally invasive surgical system a command based on the system control parameter.

<CIT> discloses techniques and structures for aligning for robotics elements with an internal surgical site with each other. Manually positional linkages support surgical instruments. These linkages maintain a fixed configuration until a brake system is released. While the brake is held in a released mode, the linkage allows the operating room personnel to manually move the linkage into alignment with the surgical site. Joints of the linkage translate the surgical instrument in three dimensions, and orient the surgical about three axis of rotation. Sensors coupled to the joints allow a processor to perform coordinate transformations that can align displayed movements of robotics actuated surgical end effectors with a surgeon's hand input at a control station.

<CIT> discloses an image capturing device which is robotically positioned and oriented in response to operator manipulation of a master control device. An unused degree-of-freedom of the master control device is used to adjust an attribute such as focusing of the image capturing device relative to a continually updated set-point. A deadband is provided to avoid inadvertent adjusting of the image capturing device attribute and haptic feedback is provided back to the master control device so that the operator is notified when adjusting of the attribute is initiated.

<CIT> discloses a digital zoom and panning system for digital video including an image acquisition device to capture digital video images; an image buffer to store one or more frames of digital video images as source pixels; a display device having first pixels to display images; a user interface to accept user input including a source rectangle to select source pixels within frames of the digital video images, a destination rectangle to select target pixels within the display device to display images, and a region of interest within the digital video images to display in the destination rectangle; and a digital mapping and filtering device to selectively map and filter source pixels in the region of interest from the image buffer into target pixels of the display device in response to the user input.

<CIT> discloses a teleoperated surgical system. A patient-side surgeon interface has components within the sterile surgical field of the surgery. The components allow a surgeon to control teleoperated slave surgical instruments from within the sterile surgical field. The patient-side surgeon interface permits a surgeon to be in the sterile surgical field adjacent a patient undergoing surgery. Controlling minimally invasive slave surgical instruments from within the sterile surgical field permits minimally invasive surgery combined with direct visualization by the surgeon. The proximity to the patient allows the surgeon to control a teleoperated slave surgical instrument in tandem with controlling manually controlled instruments such as a laparoscopic instrument. Also, the surgeon, from within the sterile surgical field, can use the patient-side surgeon interface to control at least one proxy visual in proctoring another surgeon.

<CIT> discloses telerobotic, telesurgical, and surgical robotic devices, systems, and methods which employ surgical robotic linkages that may have more degrees of freedom than an associated surgical end effector. A processor can calculate a tool motion that includes pivoting of the tool about an aperture site. Linkages movable along a range of configurations for a given end effector position may be driven toward configurations which inhibit collisions. Refined robotic linkages and method for their use are also provided.

The invention is set out in the appended claims and in the following any examples and embodiments not falling within the scope of the claims do not form part of the invention and are provided for illustrative purposes only. In accordance with an example, a control module or control process for a medical system can evaluate relationships among the control signals for multiple axes of a master control to evaluate relationships among the control signals and detect whether the master control is moving autonomously. When autonomous movement is detected, the medical system may be placed in a locked mode in which movement of the master control is decoupled from movement of an instrument or in which one or more axes of the master control are locked in their current positions. Autonomous movement detection could also provide a secondary mitigation of system failures, such as a broken master control counterbalance or an erroneous master control or tool position sensor, that could pull the master out of a physician's hand if the primary system failure mitigations do not detect the failure quickly.

One example is a teleoperated medical system that uses robotic technology. The system may include a component such as a component of a master device or of a slave device that may be configured for manual manipulation. The device generates signals indicating movement of multiple degrees of freedom of movement of the component. A detection module can be configured to analyze the signals from the component and to detect uncontrolled movement based on that analysis. When uncontrolled movement is detected, the system to switch from an operating mode to a safe mode in response to detection of uncontrolled movement of the component.

Another example is a method for controlling a teleoperated medical system. The method may include: measuring multiple degrees of freedom of a component of the robotic medical system while the component is configured for manual movement; analyzing movements of the degrees of freedom to identify uncontrolled movement of the component; and switching the robotic medical system to a safe mode in response to unsafe uncontrolled movement being detected.

The drawings illustrate examples for the purpose of explanation and are not of the invention itself. Use of the same reference symbols in different figures indicates similar or identical items.

A control system or process for interpreting manual manipulations of a multi-jointed component of a medical system can monitor independent movements in the joints to distinguish movement of the component that is likely to be user-controlled from movement of the component that is likely to be uncontrolled. For example, each of the joints or mechanical degrees of freedom of a master control for a teleoperated medical system may be categorized as either a gravity joint or a non-gravity joint. A gravity joint may be a joint such that the force of gravity might cause that joint to move if that movement is not opposed, for example, by a physician's hand. A non-gravity joint may be a joint such that the force of gravity will not cause the joint to move. Most joints in a master control may be gravity joints, but some joints, such as the joints that control tool roll or tool grip, may be non-gravity joints. Under normal operation, a user manually manipulating a master control or other multi-jointed component of a medical system may cause movement of all joints. However, if only the gravity joints move without motion of the non-gravity joints, a control system or process may determine that the component is moving in response to gravity and without user guidance. Other types of uncontrolled movement, for example, movement caused by an accidental bumping of a multi-jointed component, may be similarly detected using more complex relationships between the movements of the joints.

<FIG> illustrates a robotic medical system <NUM>, such as the da Vinci® Surgical System commercialized by Intuitive Surgical, Inc. (As used herein, the terms "robotic" or "robotically" and the like include teleoperation or telerobotic aspects. ) Such medical systems allow an operator to move a surgical tool at least in part with the assistance of a computer (an arithmetic or logic unit coupled with a memory). System <NUM> includes a patient-side cart <NUM>, a surgeon console <NUM>, and an auxiliary equipment cart <NUM>. Patient-side cart <NUM> includes multiple robotic arms <NUM>. Subsystems such as interchangeable instruments <NUM> and cameras <NUM> can be mounted on arms <NUM>. During a medical procedure, a cannula or other guide tube that may be part of arm <NUM> can be inserted through a small incision in a patient to guide the distal end of an instrument <NUM> to the work site inside the patient. Alternatively, a portion of the instrument may be introduced via a natural orifice, either with or without a cannula. An end effector, which may operate as a surgical tool such as a scalpel, forceps, a needle driver, a retractor, a cauterizer, or other device, is generally located at the distal end of each instrument <NUM> and may be used during a medical procedure performed at the work site.

Surgeon console <NUM> provides a control interface that a physician or other user can employ to control movement of arms <NUM>, instruments <NUM>, and camera <NUM>. In particular, surgeon console <NUM> may include a stereoscopic viewer presenting a sensation of depth in the space in front of the distal tip of camera <NUM>, as well as various buttons, switches, keys, foot pedals, joysticks, or similar devices that a user can manipulate to control patient-side cart <NUM> and particularly to use an end effector at the distal ends of instruments <NUM>.

Auxiliary equipment cart <NUM> may control communications between surgeon console <NUM> and patient-side cart <NUM>. In particular, cart <NUM> may include a computer system with suitable interface hardware, processing power, memory, and software to receive control signals from surgeon console <NUM> and to generate actuation signals sent to patient-side cart <NUM>. In one specific implementation, cart <NUM> includes the central processing hardware for the integrated system, including reaction to system faults and display of messaging, and surgeon console <NUM> contains processing hardware including hardware executing instructions for detecting uncontrolled movement of a user operated controls. Alternatively, processing or other control hardware for a medical system such as system <NUM> may be located in patient-side cart <NUM>, surgeon console <NUM>, auxiliary equipment cart <NUM>, or elsewhere.

All or portions of patient-side cart <NUM> may be considered a slave device under the control of a master device that forms all or parts of surgeon console <NUM>. To illustrate one example of a slave device, <FIG> schematically shows an implementation of a lower arm portion <NUM> of one of robotic arms <NUM> of <FIG>. Arm portion <NUM> in the illustrated embodiment includes a series of servomechanisms <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, each of which provides a controlled degree of freedom of movement of arm portion <NUM>. Each servomechanism <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> generally includes a drive motor or other actuator that responds to an actuation signal by moving the servomechanism along its degree of freedom of motion. Each servomechanism <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> may further include a sensing system that generates a measurement signal indicating a position or coordinate associated with the degree of freedom of the servomechanism, and the measurement signals may be used in feedback loops that control the positions of servomechanism <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>.

In the illustrated embodiment, servomechanism <NUM> may mount on patient-side cart <NUM> and particularly on an upper portion of an arm <NUM>, which controls the pose of servomechanism <NUM>. In response to an associated actuation signal, servomechanism <NUM> can rotate the distal portion of arm portion <NUM> including instrument <NUM> and servomechanisms <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> about an axis <NUM>. Servomechanism <NUM> mounts on servomechanism <NUM> and includes an actuator or motor that in response to an associated actuation signal, rotates the distal portion of arm portion <NUM> including servomechanisms <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> about an axis <NUM>, which is perpendicular to axis <NUM>. Servomechanism <NUM> mounts on servomechanism <NUM> and includes an actuator or motor that in response to an associated actuation signal, rotates the distal portion of arm portion <NUM> including servomechanisms <NUM>, <NUM>, <NUM>, and <NUM> about an axis <NUM>, which is perpendicular to axis <NUM>. Servomechanism <NUM> mounts on servomechanism <NUM> and includes an actuator or motor that in response to an associated actuation signal, rotates the distal portion of arm portion <NUM> including servomechanisms <NUM>, <NUM>, and <NUM> about an axis <NUM>, which is perpendicular to axis <NUM>. Servomechanism <NUM> mounts on servomechanism <NUM> and includes an actuator or motor that in response to an associated actuation signal, rotates the distal portion of arm portion <NUM> including servomechanisms <NUM> and <NUM> about an axis <NUM>, which is perpendicular to axis <NUM>. Servomechanism <NUM> mounts on servomechanism <NUM> and includes an actuator or motor that in response to an associated actuation signal, rotates servomechanism <NUM> about an axis <NUM>, which is perpendicular to axis <NUM>. Servomechanism <NUM> includes a docking port for instrument <NUM> and may include an actuated slide for movement of instrument <NUM> along an insertion direction <NUM>.

Instrument <NUM> typically provides further degrees of freedom of motion of a slave device that may be actuated using drive motors or other actuators in the docking port of servomechanism <NUM>. <FIG>, for example, illustrates an end effector <NUM> in an implementation in which instrument <NUM> operates as forceps. In the illustrated embodiment, end effector <NUM> is at the distal end of a main tube <NUM> of instrument <NUM> and includes a proximal clevis <NUM> mounted on the distal end of main tube <NUM>, a distal clevis <NUM> rotatably mounted on proximal clevis <NUM>, and jaws <NUM> and <NUM> rotatably mounted on distal clevis <NUM>. The degrees of freedom of this specific embodiment of end effector <NUM> may be distinguished as rotation of distal clevis <NUM> about an axis <NUM> corresponding to a pin in proximal clevis <NUM>, rotation of jaws <NUM> and <NUM> as a unit about an axis <NUM> corresponding to a pin in distal clevis <NUM>, and angular separation <NUM> of jaw <NUM> from jaw <NUM>. Each of the degrees of freedom of end effector <NUM> can be controlled using tendons, e.g., cables (not shown), that mechanically couple to one or more of mechanical elements <NUM>, <NUM>, and <NUM> and extend back through main tube <NUM> to a transmission or other backend mechanism of instrument <NUM> that couples to motors or other actuators in the docking port on arm <NUM>.

Arm portion <NUM> of <FIG> and end effector <NUM> of <FIG> are merely examples of mechanical systems that may form portions of a slave device or medical system that may be operated as described further below. More generally, many different types of robotic arms and medical instruments are known or may be developed which can be employed in slave devices of medical systems that detect uncontrolled movement of the medical system. Further, slave devices in medical systems may include other types of actuated mechanical systems such as steerable guide tubes or catheters, articulated "snake" arms, or flexible linkages.

<FIG> shows a front view of an exemplary embodiment of surgeon console <NUM>. In the illustrated embodiment, surgeon console <NUM> includes view port <NUM>, master controls <NUM>, and foot pedals <NUM>.

View port <NUM> may include a stereoscopic viewer <NUM> that displays a three-dimensional view from the point of view of a camera probe and may be used to view a work site during a medical procedure. When using surgeon console <NUM>, a physician or other user typically sits in a chair in front of surgeon console <NUM>, positions his or her head in view port <NUM> with eyes in front of viewer <NUM> and grips the master controls <NUM>, one in each hand, while resting his or her forearms on a support <NUM>. View port <NUM> may include a sensor <NUM> that senses when a user's head is in proper position for use of surgeon console <NUM>. Sensors in controllers <NUM> or a processor in surgeon console <NUM> can generate control signals in response to the motion of master controls <NUM> or indicating the configuration of master controls <NUM> and the control signals may be used in generation of actuation signals that cause movement of one or more slave devices, e.g., one or more arms <NUM> or instruments <NUM> of <FIG>. However, as a safety feature, movement of the slave devices may be disabled or limited if a sensing system, e.g., sensor <NUM>, does not detect that a user is in position for proper use of surgeon console <NUM>.

Each master control <NUM> has multiple degrees of freedom of motion that a user can manipulate by movement of a hand. In one specific implementation, the available degrees of freedom allow a user to manually control a tip <NUM> of each master controller <NUM> and particularly to manipulate: a location of tip <NUM>, e.g., x, y, and z coordinates within a limited volume; an orientation of tip <NUM>, e.g., pitch, yaw, and roll angles; and a grip angle and/or force for tip <NUM>.

<FIG> schematically illustrates one implementation of a master control <NUM> having multiple joints that permit manipulation of the location, orientation, and grip angle of a control tip <NUM>. Control tip <NUM> includes a grip angle sensor <NUM>. For example, a user may insert fingers into loops movably mounted on control tip <NUM>, and sensor <NUM> can measure a separation along axis <NUM> between the finger loops. Tip <NUM> is rotatably mounted on a link <NUM> so that a sensor <NUM> in link <NUM> can measure an angle of rotation of control tip <NUM> about an axis <NUM>. The rotation of tip <NUM> about axis <NUM> may be the roll angle of tip <NUM>. Link <NUM> is rotatably mounted on a link <NUM> to permit a sensor <NUM> to measure rotation of link <NUM> about an axis <NUM> that is perpendicular to axis <NUM>. Link <NUM> is rotatably mounted on a link <NUM> to permit a sensor <NUM> to measure rotation of link <NUM> about an axis <NUM> that is perpendicular to axis <NUM>. Link <NUM> may be rotatably mounted, and a sensor <NUM> can measure rotation of link <NUM> about an axis <NUM> that is perpendicular to axis <NUM>. A computing system can determine the position, pitch, and yaw of control tip <NUM> from the measurements of rotation angles about axes <NUM>, <NUM>, and <NUM> and the known dimensions and geometries of links <NUM>, <NUM>, and <NUM>. During a medical procedure, the location, orientation, and grip angle of tip <NUM> of master control <NUM> can be mapped to the corresponding location, orientation, and grip angle of a distal tip of an instrument or other slave device, and a control system can receive control signals from master control <NUM> that indicate the location, orientation, and grip angle of tip <NUM> and generate actuation signals for actuators that drive the corresponding location, orientation, and grip angle of the distal tip of a slave device.

<FIG> is a flow diagram of a process <NUM> that detects uncontrolled movement of a component of a robotic medical system. Process <NUM> begins with execution of a block <NUM> that measures movement of a manually operated component of a robotic medical system. The manually operated component generally has multiple degrees of freedom of motion, and in one implementation that manually operated component is a master control such as master control <NUM> of <FIG>. Movement measurement block <NUM> generally includes detection or measurement of coordinates or changes in multiple degrees of freedom of the component, e.g., measurement of current rotation angles for multiple joints of a master control.

A decision block <NUM> determines whether the measured movement is uncontrolled (or likely to be uncontrolled). For example, decision block <NUM> may determine that movement is uncontrolled if movement occurs on specific gravity joints or degrees of freedom and no movement occurs on non-gravity joints. In particular, some joints of a master control can be identified as gravity joints and some joints of a master control can be classified as non-gravity joints. The classification of a joint may be independent of the current configuration of the master control or depend on the current configuration of the master control. For example, a joint may be classified as a gravity joint only if gravity can shift or move the joint in the current configuration of a master control. Alternatively, any joint that has the possibility of being moved by gravity can be classified as a gravity joint even if gravity would not shift the joint in its current pose. A joint may be classified as a non-gravity joint if in its current pose gravity would not shift the joint, or alternatively, a joint may be classified as a non-gravity joint only if gravity would not shift the joint in any of its possible configurations. If movement occurs on at least one non-gravity joint, decision block <NUM> determines that the movement is not uncontrolled, and a block <NUM> continues the current operation of the medical system, e.g., drives a slave device to follow the movement of the master control. If movement occurs on one or more of the gravity joints but none of the non-gravity joints, block <NUM> may consider the movement to be uncontrolled, and a block <NUM> can change the operating mode of the medical system, e.g., to shift the medical system to a locked mode or otherwise prevent movement of the master or prevent movement of the slave in response to the movement of the master.

Process <NUM> may also be applied in robotic systems in which a user is manipulating a component other than a master control. For example, a medical system such as system <NUM> of <FIG> may implement a clutch mode. Clutch mode may be used when a portion of slave, e.g., a slave arm <NUM>, is not being controlled by a closed feedback loop with the master control in surgeon console <NUM>, but rather is floating or is otherwise free to move in space. Clutch mode may allow a user such as a surgical side assistant to manually manipulate and reposition an arm <NUM> relative to a patient or directly make some other clinically appropriate adjustment of the arm <NUM>. When operating in clutch mode, a control system can perform block <NUM> to measure movements in multiple degrees of freedom of arm <NUM>, and decision block <NUM> can evaluate relationships between the measured movements to determine whether movement of the arm <NUM> is uncontrolled. Clutch mode and manual movement of the arm <NUM> can continue through block <NUM> as long as the movement is controlled. However, if the slave arm <NUM> has some degrees of freedom which are affected by gravity and some degrees of freedom that are not, decision block <NUM> can apply the same logic as described above to determine whether a user is manually controlling an arm <NUM> while the arm <NUM> is operated in the clutch mode. If some of the gravity axes move more than a threshold but there is not corresponding motion of the non-gravity axes, block <NUM> could pull the arm <NUM> out of clutch mode and stop or limit further manual movement.

<FIG> is a flow diagram of a process <NUM> that detects uncontrolled movement of a master by tracking how far the tip of the master has moved since the last definitive input from the user. Definitive input in this context means that the detected movement satisfies conditions that are accepted as definitively indicating that a user controlled the movement. In general, a determination of whether movement is definitively controlled may depend on the specific master control or component being used. However, one example of definitive input may be any movement including a measured velocity or change in the roll angle of control tip <NUM> of <FIG>, if the master is such that gravity or bumping of the master cannot or is unlikely to rotate tip <NUM>. Another example of definitive input may be a measured separation along the grip axis <NUM> if the measure separation indicates that the user is holding tip <NUM> partially closed against a restoring spring force. More generally, definitive input can be logically or mathematically identified by a control system through evaluation of relationships for or among the positions, orientations, velocities, or accelerations of degrees of freedom of a master control, particularly for relationships that are indicative of input from the user's hand.

Process <NUM> begins with a block <NUM> that records the location of the tip of a master when movement of the master is identified as being definitive input. The recording of the tip position in block <NUM> may initially occur when a user initiates a "following" mode of a medical system in which the slave follows the movement of the master. After some time, a block <NUM> measures movement or a new configuration of the master, e.g., for master <NUM> of <FIG> measures angles or determines changes in angles respectively associated with one or more rotation axes <NUM>, <NUM>, <NUM>, and <NUM> or measures separation or a change in separation along axis <NUM>.

A decision block <NUM> determines whether the movement just measured definitively indicates control, i.e., corresponds to definitive input. For example, a change in the roll angle, e.g., a change in rotation angle of tip <NUM> about axis <NUM>, may indicate controlled movement or definitive input. Definitive input could also be indicated by a measured grip, e.g., a separation along axis <NUM> indicates an external force is being applied to tip <NUM>. Other indicators of definitive input are possible. If the movement is determined to be definitive input, a control system performs a block <NUM> to generate actuation signals that cause the slave to follow the movement of the master, and a new tip location for the last definitive movement is recorded by execution of block <NUM>.

If block <NUM> fails to determine that the tip movement just measured is definitive input, the movement of the master may or may not be under the control of a user. However, if the tip of the master remains within a safe range, then following can continue. Block <NUM> then determines the difference between the current tip location and the tip location recorded when tip movement last indicated definitive input, and a decision block <NUM> determines whether the movement is in a safe range. If the difference is in the safe range, the control system performs a block <NUM> to generate actuation signals that cause the slave to follow the movement of the master, and the next movement of the master is measured in block <NUM>. If the difference is outside the safe range, the slave is not permitted to follow the movement of the master, and a block <NUM> may take the medical system out of following mode. When taken out of following mode, movement of the slave is prevented until a user reestablishes the following mode, and the user may be instructed to perform a deliberate action such as squeezing the grips in order to return the medical system to following mode.

The safe range used in decision step <NUM> in general may depend on many factors, such as the pose or state of the medical system as a whole, the type of instrument or instruments currently being controlled, the current pose of the instrument(s), which degrees of freedom of the master are moved, the surgeon's operating speed, and dimensions of the work site. In an extreme case, the safe range has size zero so that no movement of the slave is permitted except when movement of the master is determined to be definitive input. However, even when uncontrolled movement of the master occurs, for example, when a user temporarily lets go of the master but the master does not move, the uncontrolled movement of the master is not necessarily a hazardous situation. The safe range can provide the thresholds based on how far the tip of the master has travelled, either linearly, or in rotation, or combined linear and rotation, for detection of unsafe uncontrolled movement. A user may thus be able to safely recover and continue in following mode after an uncontrolled movement of the master, without the system entering a safe mode and therefore without requiring the user to reenter the following mode. The time consuming process of repeatedly demonstrating control of the master or otherwise returning the medical system to following mode can thus safely be avoided.

Process <NUM> as described above analyzes movement of a master and limits movement of a slave device when the movement of a master is uncontrolled. Similar processes can also be employed when other components of a robotic medical system may be manually manipulated. For example, <FIG> is a flow diagram of a process <NUM> for operating a medical system and detecting uncontrolled movement of a slave component that might be manually manipulated. For example, the medical system may place a component such as a robotic arm into a clutch mode in which a user may directly and manually manipulate the arm. Process <NUM> begins in block <NUM> by recording a configuration in which a component is free to be manipulated (i.e., in clutch mode) and is definitively under user control. Movement of the component can be subsequently measured (block <NUM>) and a decision block <NUM> can determine if the component is then definitively under user control. If so, the component can remain in clutch mode (block <NUM>) and a new configuration can be recorded (block <NUM>). If decision block <NUM> determines that the component is not definitively under control, block <NUM> can determine the change in configuration, and block <NUM> can evaluate whether the component is in a safe range. If so, the component may remain in clutch mode (block <NUM>). If not, the system can exit clutch mode (block <NUM>) for the component.

<FIG> is a block diagram of a master-slave system <NUM> in accordance with an embodiment of the invention. System <NUM> includes a master device <NUM> that a human user may manipulate in order to control a slave device <NUM>. In one specific implementation, master device <NUM> may be similar or identical to master control <NUM> of <FIG>, but more generally, master <NUM> can be any type of device having multiple degrees of freedom of movement. Master device <NUM> generates control signals C1 to Cx indicating states or changes of its degrees of freedom.

A control system <NUM> receives control signals C1 to Cx and generates actuation signals A1 to Ay, which are sent to slave <NUM>. Control system <NUM> may be a computing system such as a general purpose computer and may include conventional components such as a processor <NUM>, memory <NUM>, and interface hardware <NUM> and <NUM> for communication with master device <NUM> and slave device <NUM>.

Control system <NUM> in the illustrated embodiment includes a mode control module <NUM>, a detection module <NUM>, a following module <NUM>, and a clutch module <NUM>. As used herein, the term "module" refers to a combination of hardware (e.g., a processor such as an integrated circuit or other circuitry) and software (e.g., machine or processor executable instructions, commands, or code such as firmware, programming, or object code). A combination of hardware and software includes hardware only (i.e., a hardware element with no software elements), software hosted at hardware (e.g., software that is stored at a memory and executed or interpreted by or at a processor), or hardware and software hosted at hardware.

Mode control module <NUM> detects when a human user initiates an operating mode such as a following mode or a clutch mode of the medical system and may switch the operating mode automatically, for example, when detection module <NUM> detects potentially unsafe uncontrolled movement in master-slave system <NUM>. In the following mode, control system <NUM> uses following module <NUM>, which receives control signals C1 to Cx and generates actuation signals A1 to Ay that cause slave device <NUM> to follow the movement of master device <NUM>. Detection module <NUM> may simultaneously monitor control signals C1 to Cx and detect any unsafe uncontrolled movement of master <NUM>. For example, in an implementation described above, mode control module <NUM> may activate following mode operation if sensor <NUM> indicates that a user is in proper position for use of master control <NUM> and the control signals indicate the human operator has depressed a grip sensor and rotate a roll sensor in the master control and may disable following mode if detection module indicates an unsafe uncontrolled movement of master <NUM>.

Following module <NUM> may perform the calculation necessary to generate actuation signals A1 to An that cause slave <NUM> to follow the movements of master <NUM>, e.g., so that the movements of slave <NUM> correspond to a mapping of the movements of master <NUM>. Following module <NUM> can be implemented using conventional techniques. Detection module <NUM> may implement process <NUM> of <FIG> and if unsafe, uncontrolled movement of master <NUM> is detected, detection module <NUM> may inform mode control module <NUM> or directly prevent following module <NUM> from generating actuation signals A1 to An that move slave <NUM>.

A clutch module <NUM> may be employed for a clutch mode of system <NUM>. In the clutch mode, movement of one or more degree of freedom of master <NUM> has no effect on the movement of one or more components of slave <NUM>. Clutch mode may be used when a portion of slave <NUM>, e.g., a slave arm, is not being controlled by a closed feedback loop with master <NUM>, but rather is floating in space and may be manually moved. For clutch mode, clutch module <NUM> may allow servo systems in slave to be freewheeling or may generate actuation signals A1 to An such that motors in an arm support the expected weight of the arm against gravity, but brakes in the arm are not engaged and instead permit manual movement of the arm. Clutch mode may allow a surgical side assistant to easily manipulate and reposition an arm or other slave component relative to a patient or directly make some other clinically appropriate adjustment of the arm or slave component. Sensor signals B1 to By from slave <NUM>, which may be used in a feedback loop control in following mode, can be analyzed by detection module <NUM> to detect uncontrolled movement of slave <NUM>. If analysis of signals B1 to By indicates uncontrolled or unsafe movement of slave <NUM>, detection module <NUM> or mode control module <NUM> can take system <NUM> out of clutch mode and may apply brakes in slave <NUM> to prevent further manual or uncontrolled movement of slave <NUM>.

Some embodiments of the above invention can be implemented in a computer-readable media, e.g., a non-transient media, such as an optical or magnetic disk, a memory card, or other solid state storage containing instructions that a computing device can execute to perform specific processes that are described herein. Such media may further be or be contained in a server or other device connected to a network such as the Internet that provides for the downloading of data and executable instructions.

Claim 1:
A teleoperated surgical system comprising:
a manually movable component comprising a plurality of links and joints, the manually movable component having a plurality of mechanical degrees of freedom, the manually movable component configured to generate a plurality of signals indicating movement of the plurality of mechanical degrees of freedom; and
a detection module coupled to the component and configured to;
identify uncontrolled movement of the component using the plurality of signals by determining that:
the plurality of signals indicate a difference between a current tip location of the manually movable component and a tip location recorded when tip movement last indicated definitive movement and that said difference is outside of a safe range; or
a mechanical degree of freedom of the manually movable component that is affected by gravity has moved, and that a mechanical degree of freedom of the component that is not affected by gravity has not moved; or
the plurality of signals indicate that no definitive input has occurred on a master control, wherein the definitive input comprises an input selected from the group consisting of a change in a roll angle and a change in a grip separation; and
command the system to switch from an operating mode to a safe mode in response to identifying an uncontrolled movement of the component,
wherein:
the component comprises the master control, the operating mode comprises a following mode in which a slave device moves in response to movement of the master control, and the safe mode comprises a mode in which the slave device is held in its position and does not move in response to movement of the master control.