Miniaturized position sensor having photolithographic coils for tracking a medical probe

• US 6,201,387 B1
• Filed: 09/24/1998
• Issued: 03/13/2001
• Est. Priority Date: 10/07/1997
• Status: Expired due to Term

• Current Assignee: Biosense, Inc. (Cardinal Health, Inc.)
• Original Assignee: Biosense, Inc. (Cardinal Health, Inc.)
• Inventors: Govari, Assaf
• Primary Examiner(s): SNOW, WALTER E
• Application Number:
  US09/160,063
• Time in Patent Office: 901 Days
• Field of Search: 324/207.17, 324/207.22, 324/207.26, 324/207.23, 336/200, 336/232, 128/899, 600/409, 600/424
• US Class Current: 324/207.17
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: A61B 5/065 Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: G01B 7/003 for measuring position, not involving coordinate determination coordinate measuring G01B7/004
• CPC Class Codes: G01B 7/004 for measuring coordinates of points
• CPC Class Codes: G01B 7/30 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01D 5/2073 by movement of a single coil with respect to two or more coils
• CPC Class Codes: G01D 5/2086 by movement of two or more coils with respect to two or more other coils
• CPC Class Codes: H01Q 7/08 Ferrite rod or like elongated core

Abstract

A miniature coil assembly for transmitting or receiving magnetic waves comprises a plurality of coils wherein each coil has a respective axis. The coil assembly is assembled such that at least two of the axes are mutually linearly independent, and such that all of the plurality of coils are contained within a volume having a cross-sectional area less than 1.0 mm². At least two of the coils are photolithographic coils.

Claims

1. A miniature coil assembly for transmitting or receiving magnetic waves for tracking a medical probe, the assembly comprising a plurality of coils, each coil having a respective axis, assembled such that at least two of the axes are mutually linearly independent, and such that all of the plurality of coils are contained within a volume having a cross-sectional area less than 1.0 mm², wherein at least two of the coils comprise photolithographic coils having respective, mutually linearly independent axes, the axes of the two photolithographic coils being mutually substantially orthogonal, and a third coil, wherein the axis of the third coil and of the two photolithographic coils are mutually linearly independent, the axis of the third coil being substantially orthogonal to the axes of the two photolithographic coils.

2. The coil assembly of claim 1, wherein all of the plurality of coils are contained within a volume having a cross-sectional area less than 0.8 mm².

3. The coil assembly of claim 2, wherein all of the plurality of coils are contained within a volume having a cross-sectional area less than 0.65 mm².

4. The coil assembly of claim 1, wherein the photolithographic coils have a width smaller than 0.8 mm.

5. The coil assembly of claim 1, wherein the photolithographic coils have a width smaller than 0.65 mm.

6. The coil assembly of claim 1, wherein the third coil is a wire-wound coil.

7. The coil assembly of claim 1, wherein the third coil comprises a plurality of interconnected photolithographic circuits.

8. The coil assembly of claim 1, wherein the two photolithographic coils comprise elongate rectangular substrates having a long side and a narrow side, and the two photolithographic coils are aligned such that the long sides of the two coils are mutually adjacent.

9. The coil assembly of claim 8, wherein the substrates of the two photolithographic coils are aligned substantially at a right angle with respect to one another.

10. The coil assembly of claim 9, wherein the assembly is circumscribed by a cylindrical volume having a diameter smaller than 1.1 mm.

11. The coil assembly of claim 10, wherein the cylindrical volume has a diameter smaller than 0.9 mm.

12. The coil assembly of claim 10, and comprising a ferromagnetic core in said volume for enhancing the inductance of the coils.

13. The coil assembly of claim 12, wherein the core comprises an elongate ellipsoidal ferrite.

14. The coil assembly of claim 13, wherein the ferrite serves as a common core for substantially all of the coils in the assembly.

15. The coil assembly of claim 1, including a position determining system for receiving signals generated by the coils responsive to an electromagnetic field and analyzing the signals to determine coordinates of the coils.

16. The coil assembly of claim 15, wherein the coils are inserted in an invasive medical probe, for finding coordinates of the probe.

17. The coil assembly of claim 16, wherein the coordinates comprise six-dimensional position and orientation coordinates.