Bone motion tracking system

• US 6,322,567 B1
• Filed: 02/09/1999
• Issued: 11/27/2001
• Est. Priority Date: 12/14/1998
• Status: Expired due to Term

• Current Assignee: Think Surgical, Inc.
• Original Assignee: Integrated Surgical Systems, Inc.
• Inventors: Cohan, Steven M., Mittelstadt, Brent D.
• Primary Examiner(s): Reip, David O.
• Assistant Examiner(s): HO, TAN-UYEN THI
• Application Number:
  US09/247,818
• Time in Patent Office: 1,022 Days
• Field of Search: 606/130, 606/1, 600/425, 600/426, 600/427, 600/429, 128/922
• US Class Current: 606/130
• CPC Class Codes: A61B 2017/00694 with means correcting for movement of or for synchronisation with the body
• CPC Class Codes: A61B 2017/564 Methods for bone or joint treatment
• CPC Class Codes: A61B 2090/363 Use of fiducial points
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 34/70 Manipulators specially adapted for use in surgery

Abstract

A method of tracking and compensating for bone motion when operating on bone (50) with surgical robotic arm (20), comprising: determining a spatial relationship between surgical robotic arm (20) and bone (50); tracking translational and rotational movements of bone (50) with a bone motion detector, which preferably comprises a passive mechanical arm (40); and updating the spatial relationship as bone (50) moves.

Claims

1. A method of tracking and compensating for bone motion when operating on a bone with a surgical robotic arm, comprising:

registering the surgical robotic arm to the bone with a six degree of freedom position sensor;

tracking movements of the bone with the six degree of freedom position sensor; and

updating the registration as the bone moves.

2. The method of claim 1, wherein registering the surgical robotic arm to the bone comprises;

attaching a plurality of marker pins to the bone;

determining the spatial relationship of the bone to the plurality of marker pins; and

registering the surgical arm to the plurality of marker pins secured to the bone.

3. The method of claim 2, wherein determining the spatial relationship of the bone to the plurality of marker pins comprises:

viewing a pre-surgical image of the bone with the plurality of marker pins attached.

4. The method of claim 1, wherein registering the surgical robotic arm to the bone comprises:

transforming a bone image data set representing an image of the bone into a robotic coordinate system of the surgical robotic arm by;

registering a bone digitizer arm to the robotic coordinate system,

generating a digitized bone data set by taking bone surface position measurements with the digitizer arm, and

transforming the bone image data set into the robotic coordinate system by performing a best fit calculation between coordinates of the bone image data set and corresponding coordinates of the digitized bone data set.

5. The method of claim 1, wherein, registering the surgical arm to the bone comprises;

comparing the position of the surgical arm to the position of anatomical features on the bone.

6. The method of claim 1, wherein, registering the surgical arm to the bone comprises;

aligning a probe on the surgical robotic arm with a medullary canal of a femur bone.

7. The method of claim 1 or 4, wherein,

registering the surgical robotic arm to the bone;

and tracking movements of the bone are performed simultaneously.

12. The method of claim 1, wherein,

tracking movements of the bone is done with an optical sensor.

13. The method of claim 1, wherein,

tracking movements of the bone is done with an ultrasound sensor.

15. The method of claim 1, 4 or 8, further comprising:

pausing operation of the surgical robotic arm concurrently with updating the registration.

17. The method of claim 1, 4 or 8, further comprising:

determining the accuracy of the surgical robotic arm by,

moving a distal end of the surgical robotic arm to contact a plurality of test structures disposed at known locations on a test fixture to generate a surgical robotic arm test data set comprising coordinates corresponding to the locations of the test structures; and

comparing the surgical robotic arm test data set to the known locations of the plurality of test structures on the test fixture.

8. A method of tracking and compensating for bone motion when operating on a bone with a surgical robotic arm, comprising:

registering the surgical robotic arm to the bone

tracking movements of the bone with a bone motion detector by;

securing a distal end of a six-degree-of-freedom mechanical arm to the bone; and

tracking translational movement of the distal end of the mechanical arm as distal end of the mechanical arm moves with the bone; and

updating the registration as the bone moves.

9. The method of claim 8, further comprising:

tracking rotational movement of the distal end of the mechanical arm as the distal end of the mechanical arm moves with the bone.

10. The method of claim 8 wherein securing the distal end of the mechanical arm to the bone comprises;

securing the distal end of the mechanical arm to the bone by a percutaneous coupling member.

11. The method of claim 10 wherein,

the distal end of the mechanical arm is secured to the bone at a location spaced sufficiently apart from where the surgical robot arm operates on the bone, such that the mechanical arm does not interfere with operation of the surgical robotic arm.

14. The method of claim 9, wherein,

the registration is updated when the distal end of the mechanical arm has moved a first threshold amount.

16. The method of claim 14, further comprising:

ceasing operation of the surgical robotic arm when the distal end of the mechanical arm has moved by a second threshold amount, wherein the second threshold amount is greater than the first threshold amount.

18. The method of claim 8, further comprising:

determining the accuracy of the mechanical arm by,

moving a distal end of the mechanical arm to contact a plurality of test structures disposed at known locations on a test fixture to generate a mechanical arm test data set comprising coordinates corresponding to the locations of the test structures; and

comparing the mechanical arm test data set to the known locations of the plurality of test structures on the test fixture.

19. The method of claim 8, further comprising:

determining the accuracy of the surgical robotic arm by,

moving a distal end of the surgical robotic arm to contact a plurality of test structures disposed at known locations on a test fixture to generate a surgical robotic arm test data set comprising coordinates corresponding to the locations of the test structures; and

comparing the surgical robotic arm test data set to the known locations of the plurality of test structures on the test fixture; and

determining the accuracy of the mechanical arm by,

moving a distal end of the mechanical arm to contact a plurality of test structures disposed at known locations on a test fixture to generate a mechanical arm test data set comprising coordinates corresponding to the locations of the test structures;

comparing the mechanical arm test data set to the known locations of the plurality of test structures on the test fixture; and

generating a transform relationship between the surgical robotic arm coordinate system and the mechanical arm coordinate system by comparing the surgical robotic arm test data set and the mechanical arm test data set.

21. The method of claim 8, wherein,

tracking translational movements of the bone with a bone motion detector comprises:

securing the distal end of a mechanical arm to the bone; and

tracking translational movement of the mechanical arm in 3 degrees of freedom as the distal end of the mechanical arm moves with the bone.

20. A method of ceasing operation of a surgical robotic arm in response to bone movement, comprising:

registering the surgical robotic arm to the bone with a six degree of freedom position sensor;

tracking translational and rotational movement of the bone with the six degree of freedom position sensor; and

ceasing operation of the surgical robotic arm when the six degree of freedom position sensor has detected a threshold amount of movement.

22. A method of tracking and compensating for bone motion when operating on a bone with a surgical robotic arm, comprising:

(a) registering the surgical robotic arm to the bone by transforming a bone image data set representing an image of the bone into a robotic coordinate system of the surgical robotic arm by;

registering a bone digitizer arm to the robotic coordinate system,

generating a digitized bone data set by taking bone surface position measurements with the digitizer arm, and

transforming the bone image data set into the robotic coordinate system by performing a best fit calculation between coordinates of the bone image data set and corresponding coordinates of the digitized bone data set;

(b) tracking movements of the bone with a bone motion detector; and

(c) updating the registration as the bone moves.