LOCALIZED MAGNETIC FIELD GENERATOR

• US 20170135602A1
• Filed: 07/01/2015
• Published: 05/18/2017
• Est. Priority Date: 07/03/2014
• Status: Active Grant

• Current Assignee: St Jude Medical International Holdings S.a.r.l.
• Original Assignee: ST JUDE MEDICAL INTERNATIONAL HOLDING S. R.L.
• Inventors: Izmirli, Alon, Eichler, Uzi, Korol, Michael, Kor, Kobi, Vaknin, Yuval
• Granted Patent: US 10,722,140 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2090/0436 Shielding
• CPC Class Codes: A61B 2090/0481 against EM radiation, e.g. microwave
• CPC Class Codes: A61B 2090/397 electromagnetic other than visible, e.g. microwave
• 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 5/062 using magnetic field
• CPC Class Codes: A61B 5/063 using impedance measurements
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: A61B 6/4441 the rigid structure being a C-arm or U-arm

Abstract

An apparatus for generating a magnetic field for tracking of an object (12) can include a localized magnetic field generator (76) that is configured to generate a magnetic field (62¹) and to control the magnetic field (62¹) in an area of interest (38) and configured to control the magnetic field (62¹) in a separate area. The separate area can be displaced from the area of interest (38) and can include a magnetic field-disrupting component (86). The object (12) can be located in the area of interest (38).

Claims

1. An apparatus for generating a magnetic field for tracking of an object, comprising the following:

a localized magnetic field generator that is configured to generate a magnetic field and to control the magnetic field in an area of interest and configured to control the magnetic field in a separate area, wherein;

the separate area is displaced from the area of interest and includes a magnetic field-disrupting component, and

the object is located in the area of interest.

2. The apparatus of claim 1, wherein the magnetic field-disrupting component moves with respect to the localized magnetic field generator.

3. The apparatus of claim 2, wherein the magnetic field-disrupting component includes at least one of an x-ray source associated with an x-ray imaging device and a c-arm associated with the x-ray imaging device.

4. The apparatus of claim 1, wherein the localized magnetic field generator is configured to decrease a strength of the magnetic field in the separate area.

5. The apparatus of claim 1, wherein the localized magnetic field generator is configured to deflect the magnetic field away from the separate area.

6. The apparatus of claim 1, wherein the localized magnetic field generator includes a plurality of magnetic transmitting elements configured to generate the magnetic field.

7. The apparatus of claim 6, wherein:

the localized magnetic field generator includes a magnetic field shield located between the plurality of magnetic transmitting elements and the magnetic field-disrupting component;

the plurality of magnetic transmitting elements are mounted in different locations; and

the plurality of magnetic transmitting elements are mounted in different orientations.

8. The apparatus of claim 1, wherein the localized magnetic field generator is configured to increase a ratio of a strength of a magnetic field located in the area of interest versus a strength of a magnetic field located in the separate area.

9. The apparatus of claim 1, wherein:

the localized magnetic field generator is configured to be placed beneath a patient examination table; and

the area of interest is located on an opposite side of the patient examination table.

10. The apparatus of claim 1, wherein the localized magnetic field generator is a mobile localized magnetic field generator configured to be placed on a patient.

11. A magnetic field generator, comprising the following:

a magnetic field shield comprising a first side and a second side; and

a plurality of magnetic transmitting elements located proximate to the magnetic field shield and on the first side of the magnetic field shield.

12. The magnetic field generator of claim 11, wherein:

the magnetic field shield forms a planar surface; and

the plurality of magnetic transmitting elements are located proximate to the planar surface and on a first side of the planar surface.

13. The magnetic field generator of claim 11, wherein the magnetic field shield comprises a planar layer of material formed from a material selected from the group consisting of a magnetically permeable material and a conductive material.

14. The magnetic field generator of claim 11, wherein the magnetic field shield comprises at least two planar layers of material, wherein one layer of material is a magnetically permeable material and the other layer of material is a conductive material.

15. The magnetic field generator of claim 11, wherein:

the magnetic field shield includes a lip formed around a perimeter of the magnetic field shield; and

the lip is formed on a same side of the magnetic field shield as the plurality of magnetic transmitting elements are located.

16. The magnetic field generator of claim 15, wherein the lip generally extends perpendicularly from the planar surface of the magnetic field shield.

17. The magnetic field generator of claim 11, wherein a length between the planar surface of the magnetic field shield and a top of the lip is in a range of 0.1 to 2.0 times a distance between the planar surface and a top of the plurality of magnetic transmitting elements.

19. The magnetic field generator of claim 11, wherein the plurality of magnetic transmitting elements include at least 3 magnetic transmitting elements.

18. A localized magnetic field generator for tracking of an object, comprising the following:

a magnetic field shield mounted beneath a patient examination table that includes at least one of a conductive material and a magnetically permeable material;

a plurality of magnetic transmitting elements connected with a first side of the magnetic field shield that faces the patient examination table;

wherein;

the magnetic field shield and the plurality of magnetic transmitting elements are configured to generate a magnetic field in an area of interest and to control the magnetic field in a separate area;

the separate area is displaced from the area of interest and includes a magnetic field-disrupting component, and

the object is located in the area of interest.

20. The magnetic field generator of claim 22, wherein the magnetic field generator generates an asymmetric magnetic field directed perpendicular to and away from the side of the magnetic field shield on which the magnetic transmitting elements are located.