ELECTROMAGNETIC TRACKING EMPLOYING SCALAR-MAGNETOMETER

• US 20090079426A1
• Filed: 09/25/2007
• Published: 03/26/2009
• Est. Priority Date: 09/25/2007
• Status: Active Grant

• Current Assignee: Stryker European Operations Holdings, LLC (Stryker Corporation)
• Original Assignee: General Electric Company
• Inventors: Anderson, Peter Traneus
• Granted Patent: US 7,834,621 B2
• Time in Patent Office: Days
• US Class Current: 324/301
• CPC Class Codes: G01R 31/31709 Jitter measurements; Jitter generators measuring jitter, noise figure or signal-to-noise ratio per se G01R29/26; analysis of tester signals G01R31/31901

Abstract

Provided is an electromagnetic tracking system, including at least one electromagnetic field receiver having at least one scalar-magnetometer, at least one electromagnetic field transmitter, and tracker electronics. Also provided is a method for electromagnetic tracking, including generating at least one magnetic field, sensing the at least one magnetic field with at least one scalar-magnetometer, and determining a relative position of the at least one scalar-magnetometer based on the sensed at least one magnetic field.

Claims

1. An electromagnetic tracking system, comprising:

at least one electromagnetic field receiver comprising at least one scalar-magnetometer;

at least one electromagnetic field transmitter; and

tracker electronics.

2. The electromagnetic tracking system of claim 1, wherein the scalar-magnetometer comprises an atomic-resonance magnetometer.

3. The electromagnetic tracking system of claim 1, wherein the at least one electromagnetic field receiver comprises two scalar-magnetometers.

4. The electromagnetic tracking system of claim 1, wherein the at least one electromagnetic field receiver comprises more than two scalar-magnetometers.

5. The electromagnetic tracking system of claim 1, wherein the tracker electronics are configured to track a position of the at least one field receiver relative to the at least one electromagnetic field transmitter based on at least one magnetic field sensed by the at least one scalar-magnetometer.

6. The electromagnetic tracking system of claim 1, wherein the at least one electromagnetic field receiver is coupled to a medical instrument.

7. The electromagnetic tracking system of claim 1, wherein the at least one electromagnetic field transmitter is coupled to a medical instrument.

8. A method for electromagnetic tracking, comprising:

generating at least one magnetic field;

sensing the at least one magnetic field with at least one scalar-magnetometer; and

determining a relative position of the at least one scalar-magnetometer based on the sensed at least one magnetic field.

9. The method of claim 8, wherein the at least one magnetic field comprises a frequency below about 8 kHz.

10. The method of claim 8, wherein sensing the at least one magnetic field with the at least one scalar-magnetometer comprises measuring the magnitude of the at least one magnetic field.

11. The method of claim 8, wherein sensing the at least one magnetic field with the at least one scalar-magnetometer comprises sensing the at least one magnetic field with more than one scalar-magnetometer.

12. The method of claim 8, wherein determining the relative position of the at least one scalar-magnetometer based on the sensed at least one magnetic field comprises calculating a distance based on a vector sum of earth'"'"'s magnetic field and the at least one magnetic field.

13. An electromagnetic tracking receiver, comprising:

a scalar-magnetometer; and

at least one electromagnetic coil disposed proximate the scalar magnetometer, and having an orientation wherein driving a current across the coil is configured to change the direction of the static field sensed by the scalar-magnetometer.

14. The electromagnetic tracking receiver of claim 13, wherein the scalar-magnetometer comprises an atomic-resonance magnetometer.

15. The electromagnetic tracking receiver of claim 13, wherein the at least one electromagnetic coil comprises three electromagnetic coils.

16. The electromagnetic tracking receiver of claim 15, wherein the three electromagnetic coils are not oriented coaxially.

17. The electromagnetic tracking receiver of claim 16, wherein the wherein the at least one electromagnetic coil comprises a coil-trio.

18. The electromagnetic tracking receiver of claim 17, wherein the scalar-magnetometer is located central to the coil-trio.

19. A method for electromagnetic tracking, comprising:

driving a plurality of coils disposed about a scalar-magnetometer to change the direction of a static field sensed by the scalar-magnetometer;

sensing magnetic fields via the scalar-magnetometer; and

determining a position of the scalar-magnetometer based on the sensed magnetic field.

20. The method of claim 19, wherein driving the plurality of coils comprises driving each of the plurality of coils in sequence.

21. The method of claim 20, wherein driving the plurality of coils in sequence comprises driving each of the coils over a time interval.

22. The method of claim 19, wherein driving the plurality of coils comprises driving each of the coils with a pulsed direct current (DC).

23. The method of claim 22, wherein the pulsed DC is configured to change the direction of a sensitivity of the scalar-magnetometer.

24. The method of claim 19, wherein driving a plurality of coils comprises driving a first coil, a second coil, and a third coil of a coil-trio in sequence one after the other.

25. The method of claim 24, wherein each of the first coil, the second coil, and the third coils are driven over a first time interval, a second time interval, and a third time interval, respectively.