FORCE AND TORQUE SENSING IN A SURGICAL ROBOT SETUP ARM

• US 20090248038A1
• Filed: 03/31/2008
• Published: 10/01/2009
• Est. Priority Date: 03/31/2008
• Status: Active Grant

• Current Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Original Assignee: Intuitive Surgical Incorporated (Intuitive Surgical Holdings, LLC)
• Inventors: Guthart, Gary S., DiMaio, Simon Peter, Dostmohamed, Hanifa, Prisco, Giuseppe M., Hasser, Christopher J., Blumenkranz, Stephen J., Dachs, Gregory William II
• Granted Patent: US 9,895,813 B2
• Time in Patent Office: Days
• US Class Current: 606/130
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• CPC Class Codes: A61B 2034/305 Details of wrist mechanisms at distal ends of robotic arms
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 34/37 Master-slave robots A61B34/35 takes precedence
• CPC Class Codes: A61B 34/71 Manipulators operated by drive cable mechanisms
• CPC Class Codes: A61B 46/10 specially adapted for instruments, e.g. microscopes
• CPC Class Codes: A61B 90/361 Image-producing devices, e.g. surgical cameras
• CPC Class Codes: A61B 90/50 Supports for surgical instruments, e.g. articulated arms
• CPC Class Codes: B25J 13/085 Force or torque sensors B25J13/082, B25J13/084 take precedence
• CPC Class Codes: G05B 2219/40582 Force sensor in robot fixture, base

Abstract

An apparatus, system, and method for improving force and torque sensing and feedback to the surgeon performing a telerobotic surgery are provided. In one embodiment, a robotic surgical manipulator system, a robotic surgical system, and a method for improved sensing of forces on a robotic surgical instrument and/or manipulator arm are disclosed.

Claims

1. A robotic surgical manipulator system, comprising:

a fixable setup linkage arm;

a servo-driven manipulator arm;

a force and torque (F/T) sensor operably coupled between a free end of the setup linkage arm and a base of the manipulator arm; and

a F/T sensor interface operably coupled to the F/T sensor for decoding signals from the F/T sensor.

2. The manipulator system of claim 1, wherein the base of the manipulator arm is a location from which at least three degrees of freedom for the manipulator arm are provided.

3. The manipulator system of claim 1, wherein the manipulator arm includes an insertion axis having a base link and a carriage link movably coupled to the base link along a lengthwise axis, the carriage link including an instrument mechanical interface.

4. The manipulator system of claim 3, wherein the instrument mechanical interface is configured to mount an instrument including a plurality of strain gauges on a distal end of an instrument shaft.

5. The manipulator system of claim 4, wherein the plurality of strain gauges are operably couplable to an instrument signal interface, and the instrument signal interface is configurable to decode signals from the plurality of strain gauges.

6. The manipulator system of claim 1, wherein the setup linkage arm is passive or motorized.

7. The manipulator system of claim 1, wherein the F/T sensor includes a spring counterbalance that compensates for the weight of the manipulator and an overhanging load moment of the manipulator.

8. The manipulator system of claim 1, wherein the F/T sensor includes a mechanical interface and an electrical connector interface that operably couple to the setup linkage arm on a first side of the F/T sensor and to the manipulator arm on a second side of the F/T sensor.

9. The manipulator system of claim 8, wherein the mechanical interface includes sliding engagement means and the electrical connector interface includes D-type connectors.

10. The manipulator system of claim 8, wherein an electrical connector interface on a first side of the F/T sensor is electrically coupled to an electrical connector interface on a second side of the F/T sensor by a wire routed around or through a main body of the F/T sensor.

11. The manipulator system of claim 8, wherein the electrical connector interface includes a serial bus through which the F/T sensor provides signals to the F/T sensor interface.

12. A robotic surgical system, comprising:

a fixable setup linkage arm;

a servo-driven manipulator arm;

a force and torque (F/T) sensor operably coupled between a free end of the setup linkage arm and a base of the manipulator arm;

a surgical instrument operably coupled to a distal end of the manipulator arm; and

an interface operably coupled to the F/T sensor for decoding signals from the F/T sensor.

13. The system of claim 12, wherein the base of the manipulator arm is a location from which at least six degrees of freedom for the instrument are provided.

14. The system of claim 12, wherein the manipulator arm includes an insertion axis having a base link and a carriage link movably coupled to the base link along a lengthwise axis, the carriage link including an instrument interface.

15. The system of claim 14, wherein the instrument is mounted to the instrument interface, the instrument including a plurality of strain gauges on a distal end of an instrument shaft.

16. The system of claim 15, wherein the plurality of strain gauges are operably coupled to an instrument signal interface, and the instrument signal interface is configured to decode signals from the plurality of strain gauges.

17. The system of claim 12, further comprising a sterile drape between the F/T sensor and the surgical instrument, the drape separating a non-sterile part of the robotic surgical system from a sterile surgical field.

18. A method of force sensing, comprising:

providing a robotic surgical manipulator system including a fixable setup linkage arm, a servo-driven manipulator arm, a force and torque (F/T) sensor operably coupled between a free end of the setup linkage arm and a base of the manipulator arm, and an interface operably coupled to the F/T sensor for decoding signals from the F/T sensor; and

sensing a force on the manipulator arm using the F/T sensor.

19. The method of claim 18, wherein the sensed force is interaction of the manipulator arm with an object exterior to the patient body.

20. The method of claim 18, further comprising mounting a surgical instrument to a distal end of the manipulator arm, and sensing a force on the surgical instrument using the F/T sensor.

21. The method of claim 20, wherein the sensed force on the instrument is one of interaction of the instrument with an internal patient anatomy, and interaction of the instrument with another surgical instrument.

22. The method of claim 20, wherein the sensed force on the instrument is one of suture tension, collision with another surgical instrument, tissue dissection, retraction, and palpation.

23. The method of claim 18, further comprising mapping forces on a patient body wall caused by tilting of a cannula within the body wall as a function of tilt angle, and subtracting the resulting estimated body wall forces from a signal from the F/T sensor.

24. The method of claim 18, further comprising increasing the backdrivability of the manipulator arm during manual positioning using data from the F/T sensor.

25. The method of claim 18, further comprising using a notch filter on a signal from the F/T sensor, the notch filter tuned to the resonance of the manipulator arm and the F/T sensor mass compliantly constrained by the setup linkage arm and patient body wall.

26. The method of claim 18, further comprising using a low-pass filter on a signal from the F/T sensor to reduce F/T sensor noise.

27. The method of claim 18, further comprising applying a threshold to a signal from the F/T sensor to eliminate forces at or below a F/T sensor noise level.

28. The method of claim 18, further comprising applying on a signal from the F/T sensor a variable gain inversely dependent on the instrument tip or manipulator arm velocity to attenuate or strengthen the sensed force.

29. The method of claim 18, further comprising draping the manipulator arm with a sterile drape such that the instrument is on a sterile side of the drape and the F/T sensor is on a non-sterile side of the drape.

30. The method of claim 18, further comprising:

mounting a surgical instrument to a distal end of the manipulator arm, the instrument including a plurality of strain gauges on a distal end of an instrument shaft;

sensing an axial force along a lengthwise axis of the instrument shaft using the F/T sensor; and

sensing side forces on the surgical instrument using the plurality of instrument strain gauges.

31. The method of claim 18, further comprising distinguishing between forces on the manipulator arm which are internal and external to a patient body based upon a magnitude of a signal from the F/T sensor.