Techniques for detecting errors or loss of accuracy in a surgical robotic system

• US 10,660,715 B2
• Filed: 12/13/2017
• Issued: 05/26/2020
• Est. Priority Date: 12/16/2016
• Status: Active Grant

• Current Assignee: MAKO Surgical Corporation (Stryker Corporation)
• Original Assignee: MAKO Surgical Corporation (Stryker Corporation)
• Inventors: Dozeman, Michael Dale
• Primary Examiner(s): Jen, Ian
• Application Number:
  US15/840,258
• Publication Number:
  US 20180168749A1
• Time in Patent Office: 895 Days
• CPC Class Codes: A61B 2034/2046 Tracking techniques
• CPC Class Codes: A61B 2034/2048 using an accelerometer or inertia sensor
• CPC Class Codes: A61B 2034/2059 Mechanical position encoders
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: B25J 9/1674 characterised by safety, monitoring, diagnostic
• CPC Class Codes: B25J 9/1694 characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception control, multi-sensor controlled systems, sensor fusion
• CPC Class Codes: G05B 2219/37288 Tracking lasers follow object, reflection gives 3-D position
• CPC Class Codes: G05B 2219/39391 Visual servoing, track end effector with camera image feedback
• CPC Class Codes: G05B 2219/45117 Medical, radio surgery manipulator
• CPC Class Codes: G05B 2219/45123 Electrogoniometer, neuronavigator, medical robot used by surgeon to operate

Abstract

Systems and methods for operating a robotic surgical system are provided. The system includes a surgical tool, a manipulator comprising a base supporting links for controlling the tool, a navigation system comprising a tracker coupled to the tool and a localizer to monitor a state of the tracker. A controller acquires raw kinematic measurement data about a state of the tool relative to the base from the manipulator, known relationship data about the state of the tracker relative to the tool, and raw navigation data about the state of the tracker relative to the localizer from the navigation system. The controller combines this data to determine a raw relationship between the base and the localizer. The raw relationship is filtered for controlling the manipulator. The raw relationship or a less filtered version of the raw relationship is utilized to determine whether an error has occurred in the system.

Claims

1. A robotic surgical system comprising:

a surgical tool;

a manipulator comprising a base supporting a plurality of links and being configured to support the surgical tool;

a navigation system comprising a tracker coupled to the surgical tool and a localizer being configured to monitor a state of the tracker; and

a controller coupled to the manipulator and the navigation system and being configured to;

acquire, from the manipulator, raw kinematic measurement data relating to a state of the surgical tool relative to the base;

acquire known relationship data relating to the state of the tracker relative to the surgical tool;

acquire, from the navigation system, raw navigation data relating to the state of the tracker relative to the localizer;

combine the raw kinematic measurement data, the known relationship data and the raw navigation data to determine a raw relationship between the base and the localizer;

filter the raw relationship according to a first filter length to produce a first filtered relationship between the base and the localizer for controlling the manipulator;

filter the raw relationship according to a second filter length being shorter than the first filter length to produce a second filtered relationship between the base and the localizer; and

utilize the second filtered relationship to determine whether an error has occurred relating to at least one of the manipulator and the localizer.

2. The robotic surgical system of claim 1 wherein the controller is further configured to utilize the second filtered relationship by comparing the first filtered relationship to the second filtered relationship to determine whether the error has occurred.

3. The robotic surgical system of claim 2 wherein the controller is further configured to compare the first filtered relationship to the second filtered relationship by determining whether a difference between the first relationship and the second filtered relationship exceeds a predetermined threshold.

4. The robotic surgical system of claim 1 wherein the controller is further configured to utilize the second filtered relationship by comparing present values of the second filtered relationship relative to past values of the second filtered relationship to determine whether the error has occurred.

5. The robotic surgical system of claim 1 wherein the first filter length is greater than or equal to 100 ms and less than or equal to 1000 ms and wherein the second filter length is greater than or equal to 0 ms and less than or equal to 50 ms.

6. The robotic surgical system of claim 1 wherein the controller is further configured to acquire the raw kinematic measurement data by acquiring one or more values of a first transform between a state of the base and the state of the surgical tool.

7. The robotic surgical system of claim 6 wherein the manipulator comprises a plurality of joints and a plurality of joint encoders and wherein the controller is further configured to acquire one or more values of the first transform by applying a forward kinematic calculation to values of the joint encoders.

8. The robotic surgical system of claim 7 wherein the controller is further configured to acquire the known relationship data by acquiring one or more values of a second transform between the state of the surgical tool and the state of the tracker.

9. The robotic surgical system of claim 8 wherein the controller is further configured to acquire the raw navigation data by acquiring one or more values of a third transform between the tracker and the localizer.

10. The robotic surgical system of claim 9 wherein the controller is further configured to combine the raw kinematic measurement data, known relationship data and the raw navigation data by combining one or more values of each of the first, second, and third transforms to determine the raw relationship.

11. The robotic surgical system of claim 1 wherein the navigation system further comprises a second tracker configured to be coupled to a patient anatomy and with the localizer being configured to monitor a state of the second tracker and wherein the controller is further configured to acquire, from the navigation system, raw navigation data relating to the state of the second tracker relative to the localizer.

12. The robotic surgical system of claim 11 wherein the controller is further configured to:

filter the raw navigation data relating to the state of the second tracker relative to the localizer to produce filtered navigation data;

combine the filtered navigation data and the first filtered relationship between the base and the localizer to produce a third filtered relationship between the base and the second tracker; and

utilize the third filtered relationship to position at least one of a haptic boundary and a tool path relative to the patient anatomy and to convert at least one of the haptic boundary and the tool path into coordinates relative to the base for controlling the manipulator.

13. The robotic surgical system of claim 1 wherein the error is further defined as at least one of:

undesired movement of the base;

undesired movement of the localizer;

failure of any one or more components of the manipulator or the localizer; and

improper calibration data.

14. The robotic surgical system of claim 1 wherein the controller is further configured to modify operation of one or more of the manipulator and the surgical tool in response to determining that the error has occurred.

15. The robotic surgical system of claim 1 wherein the controller is further configured to generate an alert or notification relating to occurrence of the error.

16. The robotic surgical system of claim 1 further comprising one or more auxiliary sensors coupled to one or more of the manipulator and the localizer and wherein the controller is further configured to analyze measurements from the one or more auxiliary sensors to determine a cause of the error.

17. A method of operating a robotic surgical system comprising a surgical tool, a manipulator comprising a base supporting a plurality of links and being configured to support the surgical tool, a navigation system comprising a tracker coupled to the surgical tool and a localizer being configured to monitor a state of the tracker, and a controller coupled to the manipulator and the navigation system and with the method comprising the controller performing the steps of:

acquiring, from the manipulator, raw kinematic measurement data relating to a state of the surgical tool relative to the base;

acquiring known relationship data relating to the state of the tracker relative to the surgical tool;

acquiring, from the navigation system, raw navigation data relating to the state of the tracker relative to the localizer;

combining the raw kinematic measurement data, the known relationship data and the raw navigation data to determine a raw relationship between the base and the localizer;

filtering the raw relationship according to a first filter length to produce a first filtered relationship between the base and the localizer for controlling the manipulator;

filtering the raw relationship according to a second filter length being shorter than the first filter length to produce a second filtered relationship between the base and the localizer; and

utilizing the second filtered relationship to determine whether an error has occurred relating to at least one of the manipulator and the localizer.

18. The method of claim 17 wherein utilizing the second filtered relationship further comprises comparing the first filtered relationship to the second filtered relationship to determine whether the error has occurred.

19. The method of claim 18 wherein comparing the first filtered relationship to the second filtered relationship further comprises determining whether a difference between the first relationship and the second filtered relationship exceeds a predetermined threshold.

20. The method of claim 17 wherein utilizing the second filtered relationship further comprises comparing present values of the second filtered relationship relative to past values of the second filtered relationship to determine whether the error has occurred.

21. The method of claim 17 wherein filtering the raw relationship according to the first filter length further comprises filtering the raw relationship according to the first filter length being greater than or equal to 100 ms and less than or equal to 1000 ms and wherein filtering the raw relationship according to the second filter length further comprises filtering the raw relationship according to the second filter length being greater than or equal to 0 ms and less than or equal to 50 ms.

22. The method of claim 17 wherein acquiring the raw kinematic measurement data further comprises acquiring one or more values of a first transform between a state of the base and the state of the surgical tool.

23. The method of claim 22 wherein the manipulator comprises a plurality of joints and a plurality of joint encoders and wherein acquiring one or more values of the first transform further comprises applying a forward kinematic calculation to values of the joint encoders.

24. The method of claim 23 wherein acquiring the known relationship data further comprises acquiring one or more values of a second transform between the state of the surgical tool and the state of the tracker.

25. The method of claim 24 wherein acquiring the raw navigation data further comprises acquiring one or more values of a third transform between the tracker and the localizer.

26. The method of claim 25 wherein combining the raw kinematic measurement data, the known relationship data and the raw navigation data further comprises combining one or more values of each of the first, second, and third transforms to determine the raw relationship.

27. The method of claim 17 wherein the navigation system further comprises a second tracker configured to be coupled to a patient anatomy and with the localizer being configured to monitor a state of the second tracker and further comprising the controller performing the step of acquiring, from the navigation system, raw navigation data relating to the state of the second tracker relative to the localizer.

28. The method of claim 27 further comprising the controller performing the steps of:

filtering the raw navigation data relating to the state of the second tracker relative to the localizer to produce filtered navigation data;

combining the filtered navigation data and the first filtered relationship between the base and the localizer to produce a third filtered relationship between the base and the second tracker; and

utilizing the third filtered relationship to position at least one of a haptic boundary and a tool path relative to the patient anatomy and to convert at least one of the haptic boundary and the tool path into coordinates relative to the base for controlling the manipulator.

29. The method of claim 17 wherein determining whether the error has occurred further comprises detecting least one of:

undesired movement of the base;

undesired movement of the localizer;

failure of any one or more components of the manipulator or the localizer; and

improper calibration data.

30. The method of claim 17 further comprising the step of modifying operation of one or more of the manipulator and the surgical tool in response to determining that the error has occurred.

31. The method of claim 17 further comprising the step of generating an alert or notification relating to occurrence of the error.

32. The method of claim 17 further comprising analyzing measurements from one or more auxiliary sensors coupled to one or more of the manipulator and the localizer to determine a cause of the error.

33. A method of operating a robotic surgical system comprising a surgical tool, a manipulator comprising a base supporting a plurality of links and being configured to support the surgical tool, a navigation system comprising a tracker coupled to the manipulator and a localizer being configured to monitor a state of the tracker, and a controller coupled to the manipulator and the navigation system and with the method comprising the controller performing the steps of:

determining a raw relationship between one or more components of the manipulator and one or more components of the navigation system using one or more of raw kinematic measurement data from the manipulator and raw navigation data from the navigation system;

filtering the raw relationship to produce a filtered relationship between the one or more components of the manipulator and the one or more components of the navigation system for controlling the manipulator; and

utilizing the raw relationship to determine whether an error has occurred relating to at least one of the manipulator and the navigation system.