Systems and methods for guiding movement of a tool
Systems and methods are provided for guiding movement of a tool. The system includes a tool and a manipulator. A guide handler obtains a target state for the tool and generates virtual constraints based on the target state and a current state of the tool. A constraint solver calculates a constraint force adapted to attract the tool toward the target state or repel the tool away from the target state based on the virtual constraints. A virtual simulator simulates dynamics of the tool in a virtual simulation based on the constraint force and input from one or more sensors, to output a commanded pose. The control system commands the manipulator to move the tool based on the commanded pose to thereby provide haptic feedback to the user that guides the user toward placing the tool at the target state or away from the target state.
1 . A surgical system comprising:
a tool;
a manipulator to support the tool and move the tool in response to user forces and torques applied to the tool by a user;
one or more sensors to measure forces and torques applied to the tool; and
a control system comprising:
a guide handler to obtain a target state for the tool and generate one or more virtual constraints based on a relationship between the target state and a current state of the tool, wherein the target state comprises a target position, a target orientation, or a target pose, and the current state comprises a current position, a current orientation, or a current pose;
a constraint solver to calculate constraint forces adapted to attract the tool toward the target state or repel the tool away from the target state based on the one or more virtual constraints generated by the guide handler; and
a virtual simulator to simulate dynamics of the tool in a virtual simulation based on input from the one or more sensors and the constraint forces calculated by the constraint solver, and to output commanded poses,
the control system being configured to command the manipulator to move the tool based on the commanded poses outputted by the virtual simulator, and to thereby provide haptic feedback to the user that guides the user toward placing the tool at the target state or away from the target state.
2 . The surgical system of claim 1 , wherein the one or more virtual constraints comprise up to three virtual constraints associated with the target position and up to three virtual constraints associated with the target orientation.
3 . The surgical system of claim 1 , wherein the control system is configured to enable the user to reorient the tool away from the target orientation.
4 . The surgical system of claim 1 , wherein the control system is configured to enable the user to reposition the tool away from the target position.
5 . The surgical system of claim 1 , wherein the target state comprises a target coordinate system and the tool comprises a guided coordinate system, the constraint forces adapted to attract the guided coordinate system toward the target coordinate system.
6 . The surgical system of claim 1 , wherein the guide handler is configured to compute the one or more virtual constraints with respect to one or more degrees of freedom based on a difference between the current state and the target state.
7 . The surgical system of claim 1 , wherein the control system comprises a user interface to activate the one or more virtual constraints so that the constraint forces comprises components of force and torque associated with attracting the tool toward the target state.
8 . The surgical system of claim 1 , wherein each of the one or more virtual constraints has a value for a tuning parameter, the guide handler being configured to change the value of the tuning parameter based on a relationship between the current state and the target state.
9 . The surgical system of claim 1 , wherein the one or more virtual constraints comprises a first virtual constraint that has a first value for a tuning parameter and a second virtual constraint that has a second value for the tuning parameter, the first value being different than the second value so that the calculated constraint forces are is adapted to attract or repel the tool more strongly as a result of the first virtual constraint as compared the second virtual constraint.
10 . The surgical system of claim 1 , wherein the virtual simulator is configured to simulate dynamics of the tool by representing the tool as a virtual rigid body having a virtual mass and by applying the constraint forces to the virtual mass in the virtual simulation to yield the commanded poses.
11 . The surgical system of claim 1 , wherein the control system is configured to:
calculate an external force based on input from the one or more sensors; and
calculate a total force for use in the virtual simulation based on the constraint forces and the external force, wherein the external force is capable of having components of force with magnitude and direction sufficient to overcome the constraint forces.
12 . The surgical system of claim 1 , wherein the tool comprises a bur or a drill and the one or more virtual constraints comprise two virtual constraints defined to attract the bur or the drill toward a desired orientation.
13 . The surgical system of claim 1 , wherein the tool comprises a bur and the one or more virtual constraints comprise three virtual constraints defined to attract the bur toward a desired starting position.
14 . The surgical system of claim 1 , wherein the tool comprises a saw blade and the one or more virtual constraints comprise three virtual constraints defined to attract the saw blade toward a desired cutting plane.
15 . A method of guiding a tool supported by a manipulator of a surgical system, the manipulator supporting and moving the tool in response to user forces and torques applied to the tool by a user, the method comprising the steps of:
receiving input from one or more sensors that measure forces and torques applied to the tool;
obtaining a target state for the tool, the target state comprises a target position, a target orientation, or a target pose;
generating one or more virtual constraints based on a relationship between the target state and a current state of the tool, wherein the current state comprises a current position, a current orientation, or a current pose;
calculating constraint forces adapted to attract the tool toward the target state or repel the tool away from the target state based on the one or more virtual constraints generated from the relationship between the target state and the current state;
simulating dynamics of the tool in a virtual simulation based on the input from the one or more sensors and the constraint forces; outputting commanded poses based on the virtual simulation; and commanding the manipulator to move the tool based on the commanded poses to thereby provide haptic feedback to the user that guides the user toward placing the tool at the target state or away from the target state.
16 . The method of claim 15 , wherein the one or more virtual constraints comprise up to three virtual constraints associated with the target position and up to three virtual constraints associated with the target orientation.
17 . The method of claim 15 , comprising enabling the user to reorient the tool away from the target orientation.
18 . The method of claim 15 , comprising enabling the user to reposition the tool away from the target position.
19 . The method of claim 15 , wherein the target state comprises a target coordinate system and the tool comprises a guided coordinate system, the constraint forces adapted to attract the guided coordinate system toward the target coordinate system.
20 . The method of claim 15 , comprising computing the one or more virtual constraints with respect to one or more degrees of freedom based on a difference between the current state and the target state.
21 . The method of claim 15 , comprising activating the one or more virtual constraints so that the constraint forces comprise components of force and torque associated with attracting the tool toward the target state.
22 . The method of claim 15 , comprising changing a value of a tuning parameter of the one or more virtual constraints based on a relationship between the current state and the target state.
23 . The method of claim 15 , comprising setting a tuning parameter for a first virtual constraint of the one or more virtual constraints at a first value and setting the tuning parameter for a second virtual constraint of the one or more virtual constraints at a second value, the first value being different than the second value so that the calculated constraint forces are is adapted to attract or repel the tool more strongly as a result of the first virtual constraint as compared the second virtual constraint.
24 . The method of claim 15 , comprising simulating dynamics of the tool by representing the tool as a virtual rigid body having a virtual mass and by applying the constraint forces to the virtual mass in the virtual simulation to poses.
25 . The method of claim 15 , comprising:
calculating an external force based on the input from the one or more sensors; and
calculating a total force for use in the virtual simulation based on the constraint forces and the external force, wherein the external force is capable of having components of force with magnitude and direction sufficient to overcome the constraint forces.
26 . The method of claim 15 , comprising defining two virtual constraints of the one or more virtual constraints to attract the tool toward a desired orientation, wherein the tool comprises a bur or a drill.
27 . The method of claim 15 , comprising defining three virtual constraints of the one or more virtual constraints to attract the tool toward a desired starting position, wherein the tool comprises a bur.
28 . The method of claim 15 , comprising defining three virtual constraints of the one or more virtual constraints to attract the tool toward a desired cutting plane, wherein the tool comprises a saw blade.
29 . A surgical system comprising:
a tool;
a manipulator to support the tool and move the tool; and
a control system comprising:
a guide handler to obtain a target state for the tool and generate one or more virtual constraints based on a relationship between the target state and a current state of the tool, wherein the target state comprises a target position, a target orientation, or a target pose, and the current state comprises a current position, a current orientation, or a current pose; and
a constraint solver to calculate constraint forces force adapted to attract the tool toward the target state or repel the tool away from the target state based on the one or more virtual constraints generated by the guide handler,
wherein movement of the tool is controlled by the manipulator, based on the constraint forces based on the output of the guide handler and constraint solver, to provide haptic feedback to guide a user toward placing the tool at the target state or away from the target state.
30 . A method of guiding a tool supported by a manipulator of a surgical system, the method comprising the steps of:
obtaining a target state for the tool wherein the target state comprises a target position, a target orientation, or a target pose;
generating one or more virtual constraints based on a relationship between the target state and a current state of the tool, wherein the current state comprises a current position, a current orientation, or a current pose;
calculating constraint forces force adapted to attract the tool toward the target state or repel the tool away from the target state based on the one or more virtual constraints generated based on the relationship between the target state and the current state; and
controlling movement of the tool based on the constraint forces to provide haptic feedback that guides a user toward placing the tool at the target state or away from the target state.
31 . The surgical system of claim 29 , wherein the one or more virtual constraints comprise up to three virtual constraints associated with the target position and up to three virtual constraints associated with the target orientation.
32 . The surgical system of claim 29 , wherein the control system is configured to enable the user to reorient the tool away from the target orientation.