Method and system for calibrating deformed instruments

• US 20050222793A1
• Filed: 04/02/2004
• Published: 10/06/2005
• Est. Priority Date: 04/02/2004
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Lea, Jon Thomas, Lloyd, Charles Frederick, Grimaud, Michel, Levine, Lewis J., Li, Alex Dun
• Application Number:
  US10/817,652
• Publication Number:
  US 20050222793A1
• Time in Patent Office: Days
• US Class Current: 702/104
• CPC Class Codes: A61B 2034/102 Modelling of surgical devices, implants or prosthesis
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 2034/207 Divots for calibration
• CPC Class Codes: A61B 2090/0813 Accessories designed for easy sterilising, i.e. re-usable
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 90/36 Image-producing devices or illumination devices not otherwise provided for

Abstract

Certain embodiments of the present invention provide a system and method for calibrating an instrument for an image-guided operation. The method includes placing a plurality of fiducials on an instrument, obtaining a plurality of measurements for the instrument using the plurality of fiducials, determining a representation of the instrument in a reference coordinate system using the plurality of measurements for use in tracking the instrument, and performing an image-guided operation using an image data set and representation of the instrument. The representation may be a closed form registration for the instrument. The measurements for the instrument may be obtained using a plurality of fiducials and a sensor. The fiducials may be indentations and/or grooves in the instrument. In an embodiment, the representation of the instrument is dynamically updated during an image-guided operation. In an embodiment, the representation of the instrument is compared to a computer-generated model of the instrument.

Claims

1. A system for improved calibration of an instrument, said system comprising:

an instrument for use in an image-guided operation, said instrument tracked with respect to a reference coordinate system during said image-guided operation;

a plurality of fiducials placed on said instrument, said plurality of fiducials enabling measurement of said instrument;

a sensor for measuring said instrument, said sensor capable of being positioned with respect to one or more of said fiducials for measurement of one or more locations on said instrument; and

a tracking system for measuring one or more locations on said instrument using said sensor and said plurality of fiducials.

2. The system of claim 1, wherein said plurality of fiducials comprise at least one of an indentation and a groove.

3. The system of claim 1, wherein said sensor comprises at least one of an electromagnetic sensor, an optical sensor, an ultrasound sensor, and an inertial position sensor.

4. The system of claim 1, wherein said sensor and said tracking system comprise a sterile sensor and sterile tracking system.

5. The system of claim 1, wherein said tracking system uses closed form registration to calibrate said instrument.

6. The system of claim 1, wherein said tracking system compares measurements from said instrument with a theoretical model for said instrument.

7. The system of claim 1, further comprising a measurement frame for positioning said instrument for measurement.

8. An improved method for calibrating an instrument, said method comprising:

placing a plurality of fiducials on an instrument;

obtaining a plurality of measurements for said instrument using said plurality of fiducials; and

forming a model of said instrument using said plurality of measurements for use in tracking said instrument.

9. The method of claim 8, further comprising generating a mathematical model of said instrument.

10. The method of claim 9, further comprising comparing said model of said instrument and said mathematical model of said instrument to determine a variation.

11. The method of claim 10, further comprising adjusting tracking of said instrument based on said variation.

12. The method of claim 8, further comprising determining a closed form registration of said instrument using said plurality of measurements and said model to calibrate said instrument.

13. The method of claim 8, further comprising obtaining a plurality of measurements for said instrument after said instrument has been deformed.

14. A method for dynamic calibration of an instrument for use in an image-guided operation, said method comprising:

obtaining a plurality of measurements for said instrument using a plurality of fiducials on an instrument;

determining a representation of said instrument in a reference coordinate system using said plurality of measurements for use in tracking said instrument; and

performing an image-guided operation using an image data set and representation of said instrument.

15. The method of claim 14, wherein said determining step further comprises determining a closed form registration for said instrument using said plurality of measurements.

16. The method of claim 14, wherein said obtaining step further comprises obtaining said plurality of measurements for said instrument using said plurality of fiducials and a sensor.

17. The method of claim 14, wherein said obtaining step further comprises obtaining said plurality of measurements for said instrument using said plurality of fiducials in at least one image of said instrument.

18. The method of claim 14, wherein said plurality of measurements are obtained in a sterile environment.

19. The method of claim 14 wherein said plurality of fiducials comprise at least one of an indentation, a groove, and an identifying feature in said instrument.

20. The method of claim 14, further comprising dynamically updating said representation of said instrument during said image-guided operation.

21. The method of claim 14, further comprising comparing said representation of said instrument and a computer-generated model of said instrument.