Surgical manipulator and method of operating the same using virtual rigid body modeling preliminary

1. A surgical manipulator comprising:

a surgical instrument including an energy applicator;

an arm comprising a plurality of links and joints, wherein an angle between adjacent links forms a joint angle, and the arm comprising a distal end configured to support the surgical instrument; and

at least one controller coupled to the arm and configured to control operation of the surgical manipulator in a manual mode or a semi-autonomous mode by being configured to:

model the surgical instrument and the energy applicator as a virtual rigid body;

selectively apply a plurality of input forces and/or torques to the virtual rigid body to simulate orientation and movement of the surgical instrument and the energy applicator;

selectively adjust the plurality of input forces and/or torques based on whether the surgical manipulator is operated in the manual mode or the semi-autonomous mode;

determine a commanded pose for the surgical instrument and the energy applicator based on the selective application and adjustment of the plurality of input forces and/or torques; and

determine commanded joint angles for the arm that place the surgical instrument and the energy applicator according to the commanded pose.

2. The surgical manipulator of claim 1 , wherein in the manual mode, the plurality of input forces and/or torques include forces and/or torques applied to the surgical instrument by a user, wherein the forces and/or torques applied by the user indicate a desired pose of the surgical instrument by the user, and wherein the at least one controller emulates the desired pose of the surgical instrument by being configured to place the surgical instrument and the energy applicator according to the commanded pose.

3. The surgical manipulator of claim 1 , wherein in the semi-autonomous mode, the plurality of input forces and/or torques include forces and/or torques directed to advancement of the surgical instrument and the energy applicator along a predefined path and forces and/or torques directed to maintenance of an orientation of the surgical instrument along the predefined path.

4. The surgical manipulator of claim 3 , wherein in the semi-autonomous mode, the at least one controller is configured to enable a user to reorient the surgical instrument while the surgical instrument advances along the predefined path.

5. The surgical manipulator of claim 3 , wherein in the semi-autonomous mode, the at least one controller is configured to enable a user to adjust a feed rate of the surgical instrument while the surgical instrument advances along the predefined path.

6. The surgical manipulator of claim 1 , wherein the at least one controller is configured to selectively balance a relative contribution of each of the plurality of input forces and/or torques by applying coefficients to each of the plurality of forces and/or torques.

7. A method of operating a surgical manipulator, wherein the surgical manipulator includes an arm comprising a plurality of links and joints, wherein an angle between adjacent links forms a joint angle, and the arm comprising a distal end configured to support a surgical instrument including an energy applicator, and at least one controller coupled to the arm, the method comprising:

controlling, with the at least one controller, operation of the surgical manipulator in a manual mode or a semi-autonomous mode by:

modeling, with the at least one controller, the surgical instrument and the energy applicator as a virtual rigid body;

selectively applying, with the at least one controller, a plurality of input forces and/or torques to the virtual rigid body for simulating orientation and movement of the surgical instrument and the energy applicator;

selectively adjusting, with the at least one controller, the plurality of input forces and/or torques based on whether the surgical manipulator is operated in the manual mode or the semi-autonomous mode;

determining, with the at least one controller, a commanded pose for the surgical instrument and the energy applicator based on the selectively applying and adjusting the plurality of input forces and/or torques; and

determining, with the at least one controller, commanded joint angles for the arm for placing the surgical instrument and the energy applicator according to the commanded pose.

8. The method of claim 7 , wherein selectively adjusting the plurality of input forces and/or torques includes the at least one controller performing one or more of: applying a weighting coefficient to one or more forces and/or torques, setting a value of one or more forces and/or torques to zero; and increasing or decreasing one or more forces and/or torques.

9. The method of claim 7 , further including computing, with the at least one controller, a total force and a total torque, wherein the total force and total torque are applied to a center of gravity of the virtual rigid body.

10. The method of claim 9 , wherein the total force and the total torque are a sum of an instrument force vector, an orientation force vector, and an environmental force.

11. The method of claim 10 , wherein:

the instrument force vector is a vector having three distinct forces and three distinct torques, the instrument force vector being selectively applied to the virtual rigid body to emulate advancement of the energy applicator at a particular velocity; and

the orientation force vector is a force and torque vector selectively applied to the virtual rigid body to emulate repositioning of an axis of the surgical instrument towards a centering point.

12. The method of claim 10 , wherein:

the environmental force includes a plurality of force inputs that include one or more of: a joint limit force, an interference limit force, a workspace boundary force, an external force and a damping force; and

comprising determining, with the at least one controller, the environmental force by summing the plurality of force inputs.

13. The method of claim 12 , further including selectively balancing, with the at least one controller, a relative contribution of each force input by applying coefficients to each of the plurality of force inputs.

14. The method of claim 13 , further including varying, with the at least one controller, the coefficients as a function of a transition between the manual mode and the semi-autonomous mode such that the coefficients are increased or decreased over a time interval following the transition.

15. The method of claim 7 , further including determining, with the at least one controller, a commanded velocity at which the energy applicator is advanced, wherein the commanded velocity is determined based on a summation of the plurality of forces and/or torques.