Electromagnetic tracking method and system

• US 20080186018A1
• Filed: 02/05/2007
• Published: 08/07/2008
• Est. Priority Date: 02/05/2007
• Status: Active Grant

• Current Assignee: Stryker European Operations Holdings, LLC (Stryker Corporation)
• Original Assignee: General Electric Company
• Inventors: Anderson, Peter Traneus
• Granted Patent: US 7,782,046 B2
• Time in Patent Office: Days
• US Class Current: 324/207.11
• CPC Class Codes: G01B 7/004 for measuring coordinates of points
• CPC Class Codes: H01F 5/003 Printed circuit coils
• CPC Class Codes: H01F 7/20 without armatures cores H01F3/00; coils H01F5/00 ; shaping metal by applying magnetic forces B21D26/14; electromagnets specially adapted for NMR applications G01R33/381

Abstract

Provided is an electromagnetic coil arrangement comprising a set of electromagnetic sensors at fixed locations with respect to each other, each of the electromagnetic sensors comprising a planar coil coupled to a conductive layer, the planar coil comprising non-concentric rings. Further, provided is an electromagnetic tracking system, comprising an electromagnetic coil arrangement, at least one complementary electromagnetic sensor and a processor configured to process a signal comprising data indicative of a mutual inductance between the at least one complementary electromagnetic sensor and each of the set of the electromagnetic sensors of the electromagnetic coil arrangement. Also, provided are a method of tracking and a method of manufacturing an electromagnetic coil arrangement.

Claims

1. An electromagnetic coil arrangement comprising:

a set of electromagnetic sensors at fixed locations with respect to each other, each of the electromagnetic sensors comprising a planar coil coupled to a conductive layer, the planar coil comprising non-concentric rings.

2. The electromagnetic coil arrangement of claim 1, wherein each planar coil is configured such that a drive current applied across the non-concentric rings of the respective planar coil provides a magnetic field, the magnetic field comprising a moment vector that is tilted at an angle from normal to the respective planar coil.

3. The electromagnetic coil arrangement of claim 1, wherein at least one of the electromagnetic sensors comprises second non-concentric rings and third non-concentric rings such that the non-concentric rings, the second non-concentric rings, and the third non-concentric rings are configured to form a coil trio.

4. The electromagnetic coil arrangement of claim 3, wherein the coil trio is configured to generate three magnetic fields having dipole moment vectors that are generally orthogonal relative to each other.

5. The electromagnetic coil arrangement of claim 1, wherein the set of electromagnetic sensors are arranged about a volume in a substantially hexahedron configuration.

6. The electromagnetic coil arrangement of claim 5, wherein the set of electromagnetic sensors comprises at least one center electromagnetic sensor located at or near the center of at least one face of the substantially hexahedron configuration.

7. The electromagnetic coil arrangement of claim 1, wherein the set of electromagnetic sensors comprises a plurality of electromagnetic sensors located about the periphery of a region.

8. The electromagnetic coil arrangement of claim 7, wherein the set of the electromagnetic sensors comprises a center electromagnetic sensor located at or near the center of the region.

9. The electromagnetic coil arrangement of claim 7, wherein the electromagnetic sensors are arranged about the periphery of the region in a substantially quadrilateral configuration located in a single plane.

10. The electromagnetic coil arrangement of claim 1, wherein the set of the electromagnetic sensors comprises a plurality of substantially quadrilateral sensor configurations that are configured to form a grid of electromagnetic sensors located in a single plane.

11. The electromagnetic sensor arrangement of claim 1, wherein the conductive layer is coupled to the planar coil via an insulating substrate.

12. An electromagnetic tracking system, comprising:

an electromagnetic coil arrangement, the electromagnetic coil arrangement comprising a set of electromagnetic sensors at fixed locations with respect to each other, each of the electromagnetic sensors comprising a planar coil coupled to a conductive layer, the planar coil comprising non-concentric rings;

at least one complementary electromagnectic sensor; and

a processor configured to process a signal comprising data indicative of a mutual inductance between the at least one complementary electromagnetic sensor and each of the set of the electromagnetic sensors of the electromagnetic coil arrangement.

13. The electromagnetic tracking system claim 12, wherein each of the planar coils is configured such that a drive current applied across the non-concentric rings of the respective planar coil provides a magnetic field, the magnetic field comprising a moment vector that is tilted at an angle from normal to the respective planar coil.

14. The electromagnetic tracking system of claim 12, wherein at least one electromagnetic sensor is configured to generate three magnetic fields having dipole moment vectors that are generally orthogonal relative to each other.

15. The electromagnetic tracking system of claim 12, wherein the set of electromagnetic sensors are arranged about a volume in a substantially hexahedron configuration.

16. The electromagnetic tracking system of claim 15, wherein the set of electromagnetic sensors comprises at least one center electromagnetic sensor located at or near the center of at least one face of the substantially hexahedron configuration.

17. The electromagnetic tracking system of claim 12, wherein the set of electromagnetic sensors comprises a plurality of electromagnetic sensors located about the periphery of a region.

18. The electromagnetic tracking system of claim 17, comprising a center electromagnetic sensor located at or near the center of the region.

19. A method of electromagnetic tracking, comprising:

positioning at least one complementary electromagnetic sensor in a volume of interest with respect to a coil arrangement adjacent to the volume of interest, the coil arrangement comprising a set of electromagnetic sensors at fixed locations with respect to each other, each of the electromagnetic sensors comprising a substrate, a conductive layer coupled to the substrate, and a planar coil coupled to the substrate on an opposite side of the substrate from the conductive layer, the planar coil comprising non-concentric rings; and

sensing a magnetic field characteristic of a magnetic field generated by either the at least one complementary elecromagnetic sensor or at least one of the set of electromagnetic sensors.

20. The method of claim 19, comprising inducing a current across at least one planar coil of the set of electromagnetic sensors to generate a magnetic field having a moment vector that is tilted at an angle from the normal to a plane of the respective planar coil.

21. The method of claim 19, wherein each of the planar coils comprises second non-concentric rings and third non-concentric rings such that the non-concentric rings, the second non-concentric rings, and the third non-concentric rings are configured to form a coil trio and comprising inducing current across the coil trio of at least one of the planar coils to generate three magnetic fields having dipole moment vectors that are generally orthogonal relative to each other.

22. The method of claim 19, wherein positioning the at least one complementary electromagnetic sensor comprises positioning an instrument in the volume of interest, wherein the instrument is coupled to the at least one complementary electromagnetic sensor.

23. The method of claim 19, wherin sensing a magnetic field characteristic comprises sensing a mutual inductance between at least one of the electromagnetic sensors and the at least one complementary electromagnetic sensor.

24. The method of claim 23, comprising:

transmitting a signal indicative of the mutual inductance to a processor; and

processing the signal indicative of the mutual inductance to determine a position and/or orientation of the complemenatry electromagnetic sensor.

25. A method of manufacturing an electromagnetic coil arrangement comprising:

coupling a plurality of planar coils to a conductive layer, wherein each of the plurality of planar coils comprises non-concentric rings, wherein each of the planar coils is configured such that a drive current applied across the non-concentric rings of the respective planar coil provides a magnetic field, the magnetic field comprising a moment vector that is tilted at an angle from the normal to the respective planar coil.

27. The method of claim 25, comprising forming an insulating substrate about the plurality of the planar coils, wherein the insulating substrate is configured to electrically insulate the planar coils such that the planar coils are coupled to the conductive layer via the insulating substrate.

28. The method of claim 25, wherein at least one of the planar coils comprises second non-concentric rings and third non-concentric rings such that the non-concentric rings, the second non-concentric rings, and the third non-concentric rings are configured to form a coil trio.