MEDICAL ROBOTIC SYSTEM WITH DYNAMICALLY ADJUSTABLE SLAVE MANIPULATOR CHARACTERISTICS

• US 20090062813A1
• Filed: 08/29/2007
• Published: 03/05/2009
• Est. Priority Date: 04/07/1999
• Status: Active Grant

• Current Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Original Assignee: Intuitive Surgical Incorporated (Intuitive Surgical Holdings, LLC)
• Inventors: Prisco, Giuseppe, Bailey, David, Ikeda, Michael, Nowlin, William, Nixon, Thomas, Toth, Gregory K., Millman, Paul, Stein, Hubert
• Granted Patent: US 10,820,949 B2
• Time in Patent Office: Days
• US Class Current: 606/130
• 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 90/361 Image-producing devices, e.g. surgical cameras
• CPC Class Codes: B25J 9/1676 Avoiding collision or forbidden zones
• CPC Class Codes: G05B 2219/40146 Telepresence, teletaction, sensor feedback from slave to operator
• CPC Class Codes: G05B 2219/40405 Master slave position control
• CPC Class Codes: G05B 2219/49144 Limit movement on an axis by setting limits

Abstract

A slave manipulator manipulates a medical device in response to operator manipulation of an input device through joint control systems. The stiffness and strength of the slave manipulator are adjustable according to criteria such as the mode of operation of the slave manipulator, the functional type of the medical device currently being held by the slave manipulator, and the current phase of a medical procedure being performed using the slave manipulator by changing corresponding parameters of the control system. For safety purposes, such changes are not made until it is determined that it can be done in a smooth manner without causing jerking of the medical device. Further, an excessive force warning may be provided to surgery staff when excessive forces are being commanded on the slave manipulator for more than a specified period of time.

Claims

1. A method for dynamically adjusting a characteristic of a slave manipulator adapted to manipulate a medical device according to operator manipulation of an input device during a medical procedure performed on a patient, comprising:

determining whether the characteristic of the slave manipulator is to be adjusted by using criteria including a functional type of the medical device and a current phase of the medical procedure; and

changing the characteristic if it is determined that the characteristic is to be adjusted.

2. The method according to claim 1, wherein the characteristic includes a stiffness associated with the slave manipulator, and the determination of whether the characteristic is to be adjusted, comprises:

determining that the stiffness is to be adjusted if the functional type of the medical device is one aiming at delivering a controlled mechanical energy to an anatomic structure of the patient and the current phase of the medical procedure involves such delivery of mechanical energy by the medical device.

3. The method according to claim 2, wherein if the functional type of the medical device is of a first class of medical devices that deliver controlled mechanical energy to the anatomic structure, then the stiffness is to be adjusted so that induced movement of the medical device resulting from counter reactionary forces created during the delivery of mechanical energy to the anatomic structure is reduced.

4. The method according to claim 2, wherein if the functional type of the medical device is of a second class of medical devices that aims at stabilizing the anatomic structure, then the stiffness is to be adjusted so that the medical device is allowed limited movement when mechanically coupled to the anatomic structure.

5. The method according to claim 1, wherein the characteristic includes a stiffness associated with the slave manipulator, and the determination of whether the characteristic is to be adjusted, comprises:

determining that the stiffness is to be adjusted if the functional type of the medical device is one where the medical device is to be guided through or around an anatomic structure of the patient and the current phase of the medical procedure involves such guidance of the medical device.

6. The method according to claim 5, wherein the stiffness is to be adjusted so that induced movement of the medical device from external forces is reduced.

7. The method according to claim 1, wherein the characteristic includes a stiffness associated with the slave manipulator, and the determination of whether the characteristic is to be adjusted, comprises:

determining that the stiffness is to be adjusted if the functional type of the medical device is one where the medical device is to control positioning of an anatomic structure in the patient and the current phase of the medical procedure involves such controlled positioning of the anatomic structure by the medical device.

8. The method according to claim 7, wherein if the medical device is in the process of controlling the position of the anatomic structure in the patient, then the stiffness is to be adjusted so as resist movement of the medical device by externally applied forces.

9. The method according to claim 7, wherein the functional type of the medical device is one that retracts and holds the anatomic structure during at least one phase of the medical procedure.

10. The method according to claim 7, wherein the functional type of the medical device is one that stabilizes the anatomic structure during at least one phase of the medical procedure.

11. The method according to claim 7, wherein the characteristic further includes a strength associated with the slave manipulator, and the determination of whether the characteristic is to be adjusted, comprises:

determining that the stiffness and strength is to be adjusted if the functional type of the medical device is one where the medical device is to control positioning of an anatomic structure in the patient and the current phase of the medical procedure involves such controlled positioning of the anatomic structure by the medical device.

12. The method according to claim 11, wherein if the medical device is in the process of controlling the position of the anatomic structure in the patient, then the stiffness and strength are to be adjusted so as resist movement of the medical device by externally applied forces.

13. The method according to claim 1, wherein the characteristic includes a strength associated with the slave manipulator, and the determination of whether the characteristic is to be adjusted, comprises:

determining that the strength is to be adjusted if the functional type of the medical device is one where the medical device is to control positioning of an anatomic structure in the patient and the current phase of the medical procedure involves such controlled positioning of the anatomic structure by the medical device.

14. The method according to claim 13, wherein if the medical device is in the process of controlling the position of the anatomic structure in the patient, then the strength is to be adjusted so as resist movement of the medical device by externally applied forces.

15. The method according to claim 13, wherein the functional type of the medical device is one that retracts and holds the anatomic structure during at least one phase of the medical procedure.

16. The method according to claim 13, wherein the functional type of the medical device is one that stabilizes the anatomic structure during at least one phase of the medical procedure.

17. The method according to claim 1, wherein the characteristic further includes a strength associated with the slave manipulator, and the determination of whether the characteristic is to be adjusted, comprises:

determining that the strength is to be adjusted if the functional type of the medical device is for suturing and the current phase of the medical procedure involves such suturing using the medical device.

18. The method according to claim 1, wherein the characteristic includes a stiffness associated with the slave manipulator, and the determination of whether the characteristic is to be adjusted, comprises:

determining that the stiffness is to be adjusted if the functional type of the medical device is one where the medical device is used for ultrasound surface scanning and the current phase of the medical procedure involves such ultrasound surface scanning using the medical device.

19. The method according to claim 1, further comprising:

identifying an operative mode of the slave manipulator;

wherein the criteria used for determining whether the characteristic is to be adjusted further includes the operative mode of the robotic system.

20. The method according to claim 19, wherein the operative mode comprises a locked mode wherein the slave manipulator is non-responsive to operator manipulation of the input device and is held in place, and an unlocked mode wherein the slave manipulator is responsive to operator manipulation of the input device;

and the determination of whether the adjustable characteristic of the slave manipulator is to be adjusted depends upon whether the operative mode is in the locked mode or the unlocked mode.

21. The method according to claim 20, wherein the characteristic includes a stiffness associated with the slave manipulator in resisting movement of the slave manipulator, and the stiffness is to be adjusted so that the stiffness of the slave manipulator in locked mode is greater than the stiffness of the slave manipulator in unlocked mode.

22. The method according to claim 20, wherein the characteristic includes a strength associated with the slave manipulator, and the strength is to be adjusted so that the strength associated with the slave manipulator in locked mode is greater than the strength associated with the slave manipulator in unlocked mode.

23. The method according to claim 1, further comprising:

identifying the functional type of the medical device by electronically reading an identifier in a memory in the medical device.

24. The method according to claim 1, further comprising:

receiving an indication of the functional type of the medical device from an operator manipulating the input device through a graphical user interface.

25. The method according to claim 1, further comprising:

receiving an indication of the current phase of the medical procedure from an operator manipulating the input device through a graphical user interface.

26. A method for dynamically adjusting a characteristic of a slave manipulator adapted to manipulate a medical device according to operator manipulation of an input device as controlled by a control system during a medical procedure performed on a patient, comprising:

determining whether a change in a parameter of the control system that results in adjusting the characteristic would also result in an actuator command generated within the control system to drive an actuator of the slave manipulator that exceeds a threshold value immediately following the change in the parameter; and

changing the parameter so as to adjust the characteristic if it is determined that the characteristic is to be adjusted and the actuator command would not exceed the threshold value immediately following the change in the parameter.

27. The method according to claim 26, wherein the slave manipulator includes a joint, and the characteristic includes a stiffness of the joint in resisting externally applied forces.

28. The method according to claim 27, wherein the parameter of the control system is a position error gain.

29. The method according to claim 28, wherein the determination of whether the change in the parameter of the control system would result in the actuator command exceeding the threshold value immediately following the change in the parameter comprises:

determining the current actuator command generated within the control system using a current position error gain in the control system;

determining a prospective actuator command to be generated within the control system immediately following the change in the parameter using a new position error gain in the control system; and

determining whether an absolute value of a difference between the current and the prospective actuator command is greater than the threshold value.

30. The method according to claim 26, wherein the slave manipulator includes a joint, and the adjustable characteristic includes a maximum strength of the joint to generate a force.

31. The method according to claim 30, wherein the parameter of the control system is a limit on a path within the control system.

32. The method according to claim 31, wherein the determination of whether the change in the parameter of the control system would result in the actuator command generated within the control system exceeding the threshold value immediately following the change in the parameter comprises:

determining whether an output of the path is being limited by using a current limit on the path;

determining whether a prospective output of the path would be limited by using a new limit on the path; and

if either the output or the prospective output is limited, then determining that the actuator command generated within the control system would exceed the threshold value immediately following the change in the parameter value.

33. The method according to claim 30, further comprising:

if the actuator command exceeds a second threshold value for a programmed period of time after changing the parameter of the control system, then issuing a sensory warning of excessive force.

34. The method according to claim 33, wherein the sensory warning includes a visual warning displayed on a display screen.

35. The method according to claim 33, wherein the sensory warning includes a visual warning displayed on the slave manipulator.

36. The method according to claim 33, wherein the sensory warning includes an auditory warning.

37. The method according to claim 36, wherein the auditory warning is provided through a right speaker if the input device is being manipulated by a right hand of an operator, and through a left speaker if the input device is being manipulated by a left hand of the operator.

38. The method according to claim 33, wherein the sensory warning includes a tactile vibration.

39. The method according to claim 38, wherein the tactile vibration is provided on the input device.