Field concentrating antennas for magnetic position sensors

Patent metadata

Field	Value
Publication number	US-11367947-B2
Application number	US-201615072185-A
Country	US
Kind code	B2
Filing date	Mar 16, 2016
Priority date	Mar 16, 2015
Publication date	Jun 21, 2022
Grant date	Jun 21, 2022

Abstract

A medical device is configured for diagnosis or treatment of a tissue within a body. The medical device comprises an elongate member and a position sensor. The elongate member is configured to be received within the body, and has a lumen extending between a proximal end and a distal end. The position sensor is disposed within the lumen proximate the distal end of the deformable member. The position sensor comprises a coil wound to form a central passage and configured to generate a current flow when subject to a magnetic field, and a high-permeability antenna having at least a portion disposed outside the central passage to concentrate the magnetic field into the coil and increase the current flow.

First claim

What is claimed is:

1. A medical device configured for diagnosis or treatment of organic tissue within a patient, the medical device comprising the following:
an elongate member configured to be received within the patient, the elongate member having a lumen extending between a proximal end and a distal end; and
a position sensor disposed within the lumen proximate the distal end of the elongate member, the position sensor including
a coil wound to form a central passage and configured to generate a current flow when subject to a magnetic field, and
a high-permeability antenna having at least a portion disposed outside the central passage to concentrate the magnetic field into the coil and increase the current flow.

2. The medical device of claim 1 , wherein the high-permeability antenna includes a body passing through the central passage and having an axial length longer than that of the coil.

3. The medical device of claim 2 , wherein the body is circumferentially curved in a direction of windings of the coil.

4. The medical device of claim 2 , further including a plurality of bodies disposed adjacent the coil.

5. The medical device of claim 1 , wherein the high-permeability antenna includes a first mass disposed adjacent the coil.

6. The medical device of claim 5 , wherein the first mass is in contact with the coil outside of the central passage.

7. The medical device of claim 5 , wherein the first mass is displaced from the coil along an axis of the coil.

8. The medical device of claim 5 , further including a second mass disposed opposite the first mass relative to the coil.

9. The medical device of claim 1 , wherein the antenna includes
a first mass positioned outside of the central passage from the sensor; and
a conductor electrically coupling the first mass and the coil.

10. The medical device of claim 9 , further including a shield extending from the first mass to surround the conductor and the coil.

11. The medical device of claim 10 , wherein the antenna further includes an opening in the shield adjacent the sensor, or a ground extending through the shield from the sensor.

12. The medical device of claim 1 , wherein the antenna comprises metallic glass material.

13. The medical device of claim 1 , further comprising a core disposed completely within the central passage of the coil.

14. The medical device of claim 1 , wherein the high-permeability antenna has an outer diameter greater than that of the coil.

15. The medical device of claim 1 , further comprising:
an inner tube extending through the coil; and
a conductor extending from the coil toward the proximal end of the elongate member.

16. The medical device of claim 1 , further comprising:
an operational element disposed proximal the distal end of the elongate member; and
a handle disposed at the proximal end of the elongate member and adapted to control deflection of the distal end.

17. A position sensor assembly for a medical device, the position sensor assembly comprising:
a body defining an internal lumen;
a wire winding spirally wound around the body; and
a magnetic flux antenna offset from the wire winding along a central axis of the wire winding and within the body, wherein the magnetic flux antenna is configured and arranged to concentrate a received magnetic field into the wire winding.

18. The sensor assembly of claim 17 , wherein the antenna comprises a thin strip of material, and
wherein the magnetic flux antenna is not configured and arranged to transmit a signal.

19. The sensor assembly of claim 17 , wherein the antenna includes a first mass of material having a permeability greater than that of the wire winding; and
wherein the magnetic flux antenna is further configured and arranged via the increased magnetic flux sensed from the received magnetic field to facilitate decreased wire winding diameter, and/or number of coil windings, and/or allow for the use of wire windings with less desirable material characteristics while maintaining magnetic flux.

20. The sensor assembly of claim 17 , further comprising a core disposed within the wire winding; and
wherein the magnetic flux antenna is further configured and arranged to increase the permeability of the core or increase the magnetic field strength impacting the core.

21. The sensor assembly of claim 17 , further comprising a plurality of magnetic flux antennas disposed outside of the wire winding and within the body.

22. The sensor assembly of claim 17 , further comprising:
a conductor electrically coupling the wire winding and the magnetic flux antenna; and
a shield surrounding the wire winding and the conductor.

23. A medical device comprising:
an elongate sheath defining a lumen;
a position sensor disposed within the lumen;
an electrode exposed to an exterior of the elongate sheath; and
a magnetic antenna disposed within the sheath and apart from the position sensor, wherein the magnetic antenna is configured and arranged to receive and concentrate a magnetic field into the position sensor.

24. The medical device of claim 23 , wherein the position sensor comprises a coil, and wherein the magnetic antenna is not configured and arranged to transmit a signal.

25. The medical device of claim 24 , wherein the coil includes a core having a permeability greater than that of air.

26. The medical device of claim 25 , wherein the permeability of the magnetic antenna is greater than that of the core; and wherein the magnetic antenna is further configured and arranged to increase the permeability of the core or increase the magnetic field strength impacting the core.

27. The medical device of claim 24 , wherein the magnetic antenna comprises a thin strip of material extending generally parallel to a central axis of the coil.

28. The medical device of claim 24 , further including an additional magnetic antenna disposed apart from the other magnetic antenna.

29. A method of increasing the signal output of a magnetic position sensor, the method comprising:
configuring a magnetic position sensor comprising a coil to generate a current flow when subject to a magnetic field;
mounting the position sensor within a medical device; and
placing at least a portion of a high permeability antenna outside of the magnetic position sensor and within the medical device so as to be configured to receive and concentrate a magnetic field into the coil and increase the current flow within the coil.

30. The method of claim 29 , wherein the high permeability antenna is positioned to funnel magnetic flux to the magnetic position sensor, and wherein the high permeability antenna is not configured and arranged to transmit a signal.

31. The method of claim 29 , further comprising spacing the high permeability antenna from the magnetic position sensor along a longitudinal axis defined by a central axis of the coil.

32. The method of claim 29 , further comprising shaping the high permeability antenna to be long and skinny.

33. The method of claim 29 , further comprising connecting the magnetic position sensor and the high permeability antenna with a conductor.

34. The method of claim 33 , further comprising shielding the magnetic position sensor and the conductor with a high permeability structure.

Assignees

• St Jude Medical Int Holding Sarl

Inventors

• Buesseler Ryan Kenneth
• Houck Alexander Carson

Classifications

• A61B18/1492

  having a flexible, catheter-like structure, e.g. for heart ablation (A61B18/1477 takes precedence) · CPC title

• A61B5/062

  using magnetic field · CPC title

• A61B5/06

  Devices, other than using radiation, for detecting or locating foreign bodies {; Determining position of diagnostic devices within or on the body of the patient} · CPC title

• H01Q7/06 Primary

  with core of ferromagnetic material (H01Q7/02 takes precedence) · CPC title

• A61B2090/376

  using X-rays, e.g. fluoroscopy · CPC title