Tool grip calibration for robotic surgery

• US 9,623,563 B2
• Filed: 06/24/2015
• Issued: 04/18/2017
• Est. Priority Date: 12/06/2002
• Status: Active Grant

• Current Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Original Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Inventors: Nixon, Tom
• Primary Examiner(s): Marc, McDieunel
• Application Number:
  US14/748,647
• Publication Number:
  US 20150314451A1
• Time in Patent Office: 664 Days
• Field of Search: 700 45, 700245, 700247, 700248, 700251, 700254, 700259, 700260, 700261, 700262, 700263, 700264, 901 8, 901 9, 901 14, 901 15, 901 21, 901 22, 901 24, 901 29, 901 30, 901 34, 901 36, 901 39, 901 40, 901 44, 901 45, 901 46, 901 48, 414 4, 414 5, 414729, 414730, 414735, 4147445, 3185681, 31856811, 31856812, 31856818, 31856821, 31856824, 318646, 128897, 294907, 7447901, 606130, 623 62, 2441725
• CPC Class Codes: A61B 17/29 Forceps for use in minimally invasive surgery
• CPC Class Codes: A61B 2017/00017 Electrical control of surgical instruments
• CPC Class Codes: A61B 2017/00207 with hand gesture control or hand gesture recognition
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• CPC Class Codes: A61B 2017/00725 Calibration or performance testing
• CPC Class Codes: A61B 2034/305 Details of wrist mechanisms at distal ends of robotic arms
• CPC Class Codes: A61B 2090/066 for measuring torque
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 34/35 for telesurgery
• CPC Class Codes: A61B 34/37 Master-slave robots A61B34/35 takes precedence
• CPC Class Codes: A61B 34/70 Manipulators specially adapted for use in surgery
• CPC Class Codes: A61B 34/71 Manipulators operated by drive cable mechanisms
• CPC Class Codes: A61B 90/06 Measuring instruments not otherwise provided for
• CPC Class Codes: A61B 90/361 Image-producing devices, e.g. surgical cameras
• CPC Class Codes: B25J 9/1689 Teleoperation
• CPC Class Codes: B25J 9/1692 Calibration of manipulator
• CPC Class Codes: G05B 2219/45123 Electrogoniometer, neuronavigator, medical robot used by surgeon to operate
• CPC Class Codes: G05B 2219/49305 Store, memory on tool with control and maintenance data
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass
• CPC Class Codes: Y10S 901/39 Jaw structure
• CPC Class Codes: Y10S 901/40 : Vacuum or mangetic
• CPC Class Codes: Y10S 901/44 : inspection
• CPC Class Codes: Y10S 901/45 : Compliance
• CPC Class Codes: Y10S 901/46 : Sensing device

Abstract

Telerobotic, telesurgical, and surgical robotic devices, systems, and methods selectively calibrate end effector jaws by bringing the jaw elements into engagement with each other. Commanded torque signals may bring the end effector elements into engagement while monitoring the resulting position of a drive system, optionally using a second derivative of the torque/position relationship so as to identify an end effector engagement position. Calibration can allow the end effector engagement position to correspond to a nominal closed position of an input handle by compensating for wear on the end effector, the end effector drive system, then manipulator, the manipulator drive system, the manipulator/end effector interfacing, and manufacturing tolerances.

Claims

1. A system comprising:

an input linkage comprising a first grip member movable relative to a second grip member;

an end effector comprising a first end effector element movable relative to a second end effector element;

a robotic arm transmitting a signal in response to mounting the end effector on the robotic arm; and

a processor coupling the input linkage to the robotic arm, the processor configured to calibrate the mounted end effector in response to the signal by bringing the first and second end effector elements into mutual engagement;

wherein the input linkage and the robotic arm each have a plurality of degrees of freedom, the processor effecting movement of the robotic arm in response to articulation of the input linkage;

wherein, between mounting of the end effector and starting a surgical procedure using the end effector, the processor does not effect a calibration movement of any degree of freedom of the input linkage or the robotic arm other than said mutual engagement of the first and second end effector elements.

2. The system of claim 1, the robotic arm comprising at least one motor driving the end effector, wherein the processor comprises programming to calibrate the mounted end effector by:

monitoring a commanded torque signal to the at least one motor;

monitoring position of the first and second end effector elements; and

identifying a change in the commanded torque signal versus the position of the first and second end effector elements.

3. The system of claim 2, wherein the processor comprises programming to:

filter the commanded torque signal prior to identifying the change.

4. The system of claim 3, wherein the processor determines an end effector initial engagement configuration using a second derivative of the filtered commanded torque signal.

5. The system of claim 4, the processor configured to, during a surgical procedure, apply no additional torque to said at least one motor beyond a position of the end effector elements corresponding to the end effector initial engagement configuration.

6. The system of claim 4, wherein a feedback force is applied to the first and second grip members at a nominal closed position, and wherein the end effector initial engagement configuration corresponds to the nominal closed position.

7. The system of claim 6, wherein the first and second grip members comprise a biasing means for increasing resistance to gripping of the first and second grip members at the nominal closed position.

8. The system of claim 1, the processor further configured to calibrate the mounted end effector once per surgical procedure for each end effector mounted on the robotic arm.

9. The system of claim 1, the plurality of degrees of freedom of the input linkage comprising three orientational degrees of freedom of the first and second grip members, the plurality of degrees of freedom of the robotic arm comprising six degrees of freedom.

10. The system of claim 1, further comprising a single element end effector, wherein a single end effector signal is transmitted by the robotic arm when the single element end effector is mounted on the robotic arm, and wherein the processor does not calibrate the mounted end effector in response to the single end effector signal.

11. A method comprising:

mounting an end effector to a robotic arm movable in a plurality of degrees of freedom, the end effector comprising a first end effector element movable relative to a second end effector element;

calibrating the mounted end effector by moving at least one of the end effector elements so as to bring the end effector elements into mutual engagement, the calibrating being performed in response to the mounting of the end effector to the robotic arm;

moving a first grip member of a handle relative to a second grip member of the handle in response to gripping;

articulating the end effector elements so that the end effector elements move in correlation with the moving of the grip members of the handle; and

between the mounting the end effector and starting a surgical procedure using the end effector, not effecting a calibration movement of any degree of freedom of the robotic arm other than said calibrating the mounted end effector.

12. The method of claim 11, the calibrating further comprising:

transmitting a commanded torque signal to at least one motor of the robotic arm to move the end effector;

monitoring position of the first and second end effector elements relative to said commanded torque signal; and

identifying an end effector element initial engagement drive position from a change in relationship between the commanded torque signal and the position of the first and second end effector elements.

13. The method of claim 12, further comprising filtering the monitored position prior to the identifying.

14. The method of claim 12, wherein the identifying comprises determining a second derivative of the commanded torque signal versus the monitored position.

15. The method of claim 12, wherein the handle generates a feedback force at a nominal closed position of the handle, and wherein the identified end effector element initial engagement drive position corresponds to the nominal closed position of the handle.

16. The method of claim 15, further comprising increasing resistance to the moving the handle at the nominal closed position during a surgical procedure using the end effector.

17. The method of claim 11, further comprising removing the end effector from the robotic arm and mounting a second end effector having a single end effector element to the robotic arm, wherein a single element end effector signal is transmitted by the robotic arm when the second end effector is mounted thereon, and wherein no calibrating of the second end effector element is performed in response to the single element end effector signal.