Shielded electromagnetic transducer

• US 5,000,178 A
• Filed: 03/18/1988
• Issued: 03/19/1991
• Est. Priority Date: 05/23/1986
• Status: Expired due to Fees

• Current Assignee: Lti-Imd USA Incorporated
• Original Assignee: LTI Biomedical, Inc. A CORPORATION OF CALIFORNIA
• Inventors: Griffith, Neil J.
• Primary Examiner(s): Jaworski, Francis
• Assistant Examiner(s): Manuel, George
• Application Number:
  US07/170,361
• Time in Patent Office: 1,096 Days
• Field of Search: 128/419 F, 128/82.1, 128/419 R, 600/9, 600/10, 600/11, 600/13, 600/14, 600/15
• US Class Current: 607/2
• CPC Class Codes: A61N 2/00 Magnetotherapy

Abstract

An electrical to electromagnetic transducer for applying electromagnetic energy to damaged potions of the living body, which provides high efficiency generation of electromagnetic fields for electromagnetic therapy by directing electromagnetic radiation to the damaged body part. Electromagnetic radiation is initially generated by a dipole consisting of a bar of high permeability material wrapped with an electrically conductive coil. The dipole is placed between a conductive shield and the damaged body part. An electrical signal passes through the coil which causes a magnetic field to be generated through and around the high permeability material. The field radiation pattern of the dipole is directed toward the damaged body part by a conductive shield. Magnetic fields which are generated away from the damaged body part intersect the conductive shield and establish eddy currents. These eddy currents in turn generate magnetic fields opposite and nearly equal to the magnetic fields generated by the electromagnetic source. These resultant redirected electromagnetic fields then reinforce the electromagnetic field directed towards the damaged body part and diminish the electromagnetic field directed away from the damaged body part.

Claims

1. A transducer for converting an electrical signal into an electromagnetic field for application of said electromagnetic field to a damaged body part to promote healing of said body part, said transducer comprising

a conductive coil, said coil having first and second terminals at opposite ends of said coil, said first and second terminals connected to receive said electrical signal, said coil providing an electromagnetic field in response to said electrical signal and said coil providing said electromagnetic field to said damaged body part when placed proximal to said damaged body part;

and

a conductive plate adapted to be positioned adjacent to said conductive coil and opposite from said- damaged body part, said plate having a major surface adapted to be positioned parallel to said damaged body part and said plate extending laterally beyond said conductive coil in the direction of said major surface.

2. A transducer as in claim 1 wherein said plate includes an indentation adapted for said coil, said major surface of said plate being closer to said damaged body part in the area extending beyond said coil than the area of said major surface of said plate not extending beyond said conductive coil.

3. A transducer as in claim 2 where in said area extending beyond said coil of said major surface of said conductive plate is substantially flush with the surface of said coil nearest said damaged body part

4. A transducer as in claim 1 where said conductive plate is flexible.

5. A transducer as in claim 4 where said flexible conductive plate comprises a mesh of conductive wire.

6. A transducer as in claim 1 wherein said conductive plate comprises a layer of conductive and malleable material affixed to a flexible backing, said layer having a regular pattern of holes formed therein.

7. A transducer for converting an electrical signal into an electromagnetic field for application of said electromagnetic field to a damaged body part to promote healing of said body part, said transducer comprising:

a core piece comprising high permeability material;

a conductive coil wrapped around said core piece, said coil having first and second terminals at opposite ends of said coil, said first and second terminals connected to receive said electrical signal, said coil and said core piece providing an electromagnetic field in response to said electrical signal and said coil and core piece providing said electromagnetic field to said damaged body part when placed proximal to said damaged body part; and

a conductive plate adapted to be positioned adjacent to said core piece and conductive coil and opposite from said damaged body part, said plate having a major surface adapted to be positioned parallel to said damaged body part and said plate extending laterally beyond said core piece and conductive coil in the direction of said major surface.

8. A transducer as in claim 7 wherein said plate includes an indentation adapted for said core piece and coil, said major surface of said plate being closer to said damaged body part in the area extending beyond said core piece and conductive coil than the area of said major surface of said plate not extending beyond said core piece and conductive coil.

9. A transducer as in claim 8 where in said area extending beyond said core piece and coil of said major surface of said conductive plate is substantially flush with the surface of said core piece and coil nearest said damaged body part.

10. A transducer as in claim 7 wherein the surfaces of said core piece intersecting a line which runs perpendicularly to the planes formed by the loops of said conductive coil form an obtuse angle with the surface of said core piece adjacent to said damaged body part.

11. A transducer as in claim 7 where said conductive plate is flexible.

12. A transducer as in claim 11 where said flexible conductive plate comprises a mesh of conductive wire

13. A transducer as in claim 7 wherein said conductive plate comprises a layer of conductive and malleable material affixed to a flexible backing, said layer having a regular pattern of holes formed therein.

14. A transducer for converting an electrical signal into an electromagnetic field for application of said electromagnetic field to a damaged body part to promote healing of said body part, said transducer comprising:

a plurality of core pieces comprising high permeability material;

a conductive coil wrapped around said core pieces, said coil having first and second terminals at opposite ends of said coil, said first and second terminals connected to receive said electrical signal, said coil and said core pieces providing an electromagnetic field in response to said electrical signal and said coil and core piece providing said electromagnetic field to said damaged body part when placed proximal to said damaged body part; and

a plurality of conductive plates one for each of said core pieces adapted to be positioned adjacent to said core pieces and conductive coil and opposite from said damaged body part, said plates having a major surface adapted to be positioned parallel to said damaged body part and said plates extending beyond said core piece and conductive coil in the direction of said major surface.

15. A transducer as in claim 14 wherein said plates include an indentation adapted for said core piece and coil, said major surface of said plates being closer to said damaged body part in the area extending beyond said core pieces and conductive coil than the area of said major surface of said plate not extending beyond said core pieces and conductive coil.

16. A transducer as in claim 15 where in said area extending beyond said core piece and coil of said major surface of said conductive plate is substantially flush with the surface of said core pieces and coil nearest said damaged body part.

17. A transducer as in claim 14 wherein the surfaces of said core pieces intersecting a line which runs perpendicularly to the planes formed by the loops of said conductive coil form an obtuse angle with the surface of said core piece adjacent to said damaged body part.

18. A transducer as in claim 14 where said conductive plate is flexible.

19. A transducer as in claim 18 where said flexible conductive plate comprises a mesh of conductive wire.

20. A transducer as in claim 14 wherein said conductive plates interlock to provide a single mechanically integrated structure.

21. A transducer as in claim 14 wherein said coil is wound in one direction on one core piece and in the opposite direction on an adjacent core piece to provide opposing magnetic fields.

22. A transducer as in claim 14 wherein said coil is wrapped in the same direction on said core pieces

23. A transducer as in claim 14 wherein said conductive plate comprises a layer of conductive and malleable material affixed to a flexible backing, said layer having a regular pattern of holes formed therein.

24. A transducer for converting an electrical signal into an electromagnetic field for application of said electromagnetic field to a damaged body part to promote healing of said body part, said transducer comprising:

first and second core pieces comprising high permeability material;

a conductive coil wrapped around said first and second core pieces, said coil having first and second terminals at opposite ends of said coil, said first and second terminals connected to receive said electrical signal, said coil and said first and second core pieces providing perpendicular electromagnetic fields in response to said electrical signal and said coil and core piece providing said electromagnetic field to said damaged body part when placed proximal to said damaged body part; and

a conductive plate adapted to be positioned adjacent to said first and second core pieces and conductive coil, and opposite from said damaged body part, said plate having a major surface adapted to be positioned parallel to said damaged body part and said plate extending laterally beyond said first and second core pieces and conductive coil in the direction of said major surface.

25. A transducer as in claim 24 wherein said plate includes an indentation adapted for said first and second core pieces and coil, said major surface of said plate being closer to said damaged body part in the area extending beyond said first and second core pieces and conductive coil than the area of said major surface of said plate not extending beyond said core piece and conductive coil.

26. A transducer as in claim 25 where in said area extending beyond said core piece and coil of said major surface of said conductive plate is substantially flush with the surface of said first and second core pieces and said coil nearest said damaged body part.

27. A transducer as in claim 24 wherein the surfaces of said first and second core pieces intersecting a line which runs perpendicularly to the planes formed by the loops of said conductive coil form an obtuse angle with the surface of said first and second core pieces adjacent to said damaged body part.

28. A transducer as in claim 24 where said conductive plate is flexible.

29. A transducer as in claim 28 where said flexible conductive plate comprises a mesh of conductive wire.

30. A transducer as in claim 24 wherein said conductive plate comprises a layer of conductive and malleable material affixed to a flexible backing, said layer having a regular pattern of holes formed therein.

31. A transducer for converting an electrical signal into an electromagnetic field for application of said electromagnetic field to a damaged body part to promote healing of said body part, said transducer comprising:

a core piece comprising high permeability material said core piece being curved to conform to said damaged body part;

a conductive coil wrapped around said core piece, said coil having first and second terminals at opposite ends of said coil, said first and second terminals connected to receive said electrical signal, said coil and said core piece providing an electromagnetic field in response to said electrical signal and said coil and core piece providing said electromagnetic field to said damaged body part when placed proximal to said damaged body part; and

a conductive plate adapted to be positioned adjacent to said core piece and conductive coil and opposite from said damaged body part, said plate having a major surface adapted to be positioned parallel to said damaged body part and said plate extending beyond said core piece and conductive coil in the direction of said major surface

32. A transducer as in claim 31 wherein said plate includes an indentation adapted for said core piece and coil, said major surface of said plate being closer to said damaged body part in the area extending beyond said core piece and conductive coil than the area of said major surface of said plate not extending beyond said core piece and conductive coil.

33. A transducer as in claim 32 where in said area extending beyond said core piece and coil of said major surface of said conductive plate is substantially flush with the surface of said core piece and coil nearest said damaged body part.

34. A transducer as in claim 31 wherein the surfaces of said core piece intersecting a line which runs perpendicularly to the planes formed by the loops of said conductive coil form an obtuse angle with the surface of said core piece adjacent to said damaged body part.

35. A transducer as in claim 31 where said conductive plate is flexible.

36. A transducer as in claim 35 where said flexible conductive plate comprises a mesh of conductive wire.

37. A transducer as in claim 31 wherein said conductive plate comprises a layer of conductive and malleable material affixed to a flexible backing, said layer having a regular pattern of holes formed therein.

38. A transducer for converting an electrical signal into an electromagnetic field for application of said electromagnetic field to a damaged body part to promote healing of said body part, said transducer comprising

a core piece comprising high permeability material;

a conductive coil wrapped around said core piece, said coil having first and second terminals at opposite ends of said coil, said first and second terminals connected to receive said electrical signal, said coil and said core piece providing an electromagnetic field in response to said electrical signal and said coil and core piece providing said electromagnetic field to said damaged body part when placed proximal to said damaged body part;

a shunt piece of high permeability material placed adjacent to said damage body part; and

a conductive plate adapted to be positioned adjacent to said core piece and conductive coil and opposite from said damaged body part, said plate having a major surface adapted to be positioned parallel to said damaged body part and said plate extending beyond said core piece and conductive coil in the direction of said major surface.

39. A transducer as in claim 38 wherein said plate includes an indentation adapted for said core piece and coil, said major surface of said plate being closer to said damaged body part in the area extending beyond said core piece and conductive coil than the area of said major surface of said plate not extending beyond said core piece and conductive coil.

40. A transducer as in claim 39 where in said area extending beyond said core piece and coil of said major surface of said conductive plate is substantially flush with the surface of said core piece and coil nearest said damaged body part.

41. A transducer as in claim 38 wherein the surfaces of said core piece intersecting a line which runs perpendicularly to the planes formed by the loops of said conductive coil form an obtuse angle with the surface of said core piece adjacent to said damaged body part.

42. A transducer as in claim 38 where said conductive plate is flexible.

43. A transducer as in claim 42 where said flexible conductive plate comprises a mesh of conductive wire.

44. A transducer as in claim 38 wherein said conductive plate comprises a layer of conductive and malleable material affixed to a flexible backing, said layer having a regular pattern of holes formed therein.

45. A transducer for converting an electrical signal into an electromagnetic field for application of said electromagnetic field to a damaged body part to promote healing of said body part, said transducer comprising:

a core piece comprising high permeability material;

a plurality of electrically connected conductive coils wrapped around said core piece, said plurality of coils having first and second terminals at opposite ends of said plurality of coils, said first and second terminals connected to receive said electrical signal, said plurality of coils and said core piece providing an electromagnetic field in response to said electrical signal and said plurality of coils and core piece providing said electromagnetic field to said damaged body part when placed proximal to said damaged body part; and

a conductive plate adapted to be positioned adjacent to said core piece and plurality of conductive coils and opposite from said damaged body part, said plate having a major surface adapted to be positioned parallel to said damaged body part and said plate extending beyond said core piece and plurality of conductive coils in the direction of said major surface.

46. A transducer as in claim 45 wherein said plate includes an indentation adapted for said core piece and said plurality of coils, said major surface of said plate being closer to said damaged body part in the area extending beyond said core piece and said plurality of conductive coils than the area of said major surface of said plate not extending beyond said core piece and plurality of conductive coils.

47. A transducer as in claim 46 where in said area extending beyond said core piece and plurality of conductive coils of said major surface of said conductive plate is substantially flush with the surface of said core piece and said plurality of conductive coils nearest said damaged body part.

48. A transducer as in claim 45 wherein the surfaces of said core piece intersecting a line which runs perpendicularly to the planes formed by the loops of said plurality of conductive coils form an obtuse angle with the surface of said core piece adjacent to said damaged body part.

49. A transducer as in claim 45 where said conductive plate is flexible.

50. A transducer as in claim 48 where said flexible conductive plate comprises a mesh of conductive wire.

51. A transducer as in claim 45 wherein said conductive plate comprises a layer of conductive and malleable material affixed to a flexible backing, said layer having a regular pattern of holes formed therein.