Device and method for preventing magnetic-resonance imaging induced damage

• US 20050113873A1
• Filed: 03/08/2004
• Published: 05/26/2005
• Est. Priority Date: 04/02/2003
• Status: Abandoned Application

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Biophan Technologies Incorporated
• Inventors: Connelly, Patrick R., Weiner, Michael L., Miller, Victor R., Helfer, Jeffrey L.
• Application Number:
  US10/795,741
• Publication Number:
  US 20050113873A1
• Time in Patent Office: Days
• US Class Current: 607/2
• CPC Class Codes: A61N 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: G01R 33/285 Invasive instruments, e.g. catheters or biopsy needles, specially adapted for tracking, guiding or visualization by NMR
• CPC Class Codes: G01R 33/288 Provisions within MR facilities for enhancing safety during MR, e.g. reduction of the specific absorption rate [SAR], detection of ferromagnetic objects in the scanner room
• CPC Class Codes: G01R 33/4804 Spatially selective measurement of temperature or pH
• CPC Class Codes: Y10T 428/24322 Composite web or sheet
• CPC Class Codes: Y10T 428/24331 including nonapertured component

Abstract

An electromagnetic shield has a first patterned or apertured layer having non-conductive materials and conductive material and a second patterned or apertured layer having non-conductive materials and conductive material. The conductive material may be a metal, a carbon composite, or a polymer composite. The non-conductive materials in the first patterned or apertured layer may be randomly located or located in a predetermined segmented pattern such that the non-conductive materials in the first patterned or apertured layer are located in a predetermined segmented pattern with respect to locations of the non-conductive materials in the second patterned or apertured layer.

Claims

1. A medical assist system, comprising:

a primary device housing;

said primary device housing having a control circuit therein;

a lead system to provide an electrical path between a tissue region and said primary device housing;

a shielding formed around said lead system to shield said lead system from electromagnetic interference; and

a filter, connected to said lead system, to attenuate any induced RF signal and passing a desired electrical physiological signal;

said filter including,

a shield enclosing said filter, and

a low pass filter connected to said lead system;

said shielding being patterned with non-conductive materials and conductive materials.

2. The medical assist system as claimed in claim 1, wherein said conductive material is a metal to shield said lead system from electromagnetic interference.

3. The medical assist system as claimed in claim 1, wherein said conductive material includes metal-coated carbon filaments to shield said lead system from electromagnetic interference.

4. The medical assist system as claimed in claim 1, wherein said conductive material is a polymer composite to shield said lead system from electromagnetic interference.

5. The medical assist system as claimed in claim 1, further comprising a non-permeable diffusion resistant biocompatible material covering said shielding.

6. The medical assist system as claimed in claim 1, wherein said shielding is formed around said primary housing to shield said primary housing from electromagnetic interference.

7. The medical assist system as claimed in claim 6, wherein said conductive material is a metal to shield said lead system and said primary housing from electromagnetic interference.

8. The medical assist system as claimed in claim 6, wherein said conductive material includes metal-coated carbon filaments to shield said lead system and said primary housing from electromagnetic interference.

9. The medical assist system as claimed in claim 6, wherein said conductive material is a polymer composite to shield said lead system and said primary housing from electromagnetic interference.

10. The medical assist system as claimed in claim 1, wherein said shielding is constructed of two patterned sheaths, each patterned sheath having non-conductive materials and conductive materials.

11. The medical assist system as claimed in claim 10, wherein said conductive materials in one of said two patterned sheaths are randomly located.

12. The medical assist system as claimed in claim 10, wherein said conductive materials in said two patterned sheaths are located in a predetermined segmented pattern.

13. The medical assist system as claimed in claim 10, wherein said conductive materials in said two patterned sheaths are located in a predetermined segmented pattern with respect to a direction substantially parallel with an axis of said lead system.

14. The medical assist system as claimed in claim 10, wherein said conductive materials in said two patterned sheaths are located in a predetermined segmented pattern with respect to a direction substantially perpendicular with an axis of said lead system.

15. The medical assist system as claimed in claim 13, wherein said conductive materials in said two patterned sheaths are located in a predetermined segmented pattern with respect to a direction substantially perpendicular with an axis of said lead system.

16. The medical assist device as claimed in claim 1, wherein said filter includes a common reference line coupled to said shield, said low pass filter being connected to said common reference line.

17. The medical assist device as claimed in claim 1, wherein said shield enclosing said filter is patterned with non-conductive materials and conductive materials.

18. The medical assist device as claimed in claim 17, wherein said conductive material of said shield is a metal.

19. The medical assist device as claimed in claim 17, wherein said conductive material of said shield includes metal-coated carbon filaments.

20. The medical assist device as claimed in claim 17, wherein said conductive material of said shield is a polymer composite.

21. The medical assist device as claimed in claim 17, wherein said shield is constructed of two patterned sheaths, each patterned sheath having non-conductive materials and conductive materials.

22. The medical assist device as claimed in claim 21, wherein said conductive materials in one of said two patterned sheaths are randomly located.

23. The medical assist device as claimed in claim 21, wherein said conductive materials in said two patterned sheaths are located in a predetermined segmented pattern.

24. A medical assist system, comprising:

a primary device housing;

said primary device housing having a control circuit therein;

a lead system to provide an electrical path between a tissue region and said primary device housing;

a shielding formed around said lead system to shield said lead system from electromagnetic interference; and

a filter, connected to said lead system, to attenuate any induced RF signal and passing a desired electrical physiological signal;

said filter including,

a shield enclosing said filter, and

a low pass filter connected to said lead system;

said shielding being an apertured conductive material having a maximum aperture dimension of 0.01 millimeters to 10 millimeters.

25. The medical assist system as claimed in claim 24, wherein said conductive material is a metal to shield said lead system from electromagnetic interference.

26. The medical assist system as claimed in claim 24, wherein said conductive material includes metal-coated carbon filaments to shield said lead system from electromagnetic interference.

27. The medical assist system as claimed in claim 24, wherein said conductive material is a polymer composite to shield said lead system from electromagnetic interference.

28. The medical assist system as claimed in claim 24, further comprising a non-permeable diffusion resistant biocompatible material covering said shielding.

29. The medical assist system as claimed in claim 24, wherein said shielding is formed around said primary housing to shield said primary housing from electromagnetic interference.

30. The medical assist system as claimed in claim 29, wherein said conductive material is a metal to shield said lead system and said primary housing from electromagnetic interference.

31. The medical assist system as claimed in claim 29, wherein said conductive material includes metal-coated carbon filaments to shield said lead system and said primary housing from electromagnetic interference.

32. The medical assist system as claimed in claim 29, wherein said conductive material is a polymer composite to shield said lead system and said primary housing from electromagnetic interference.