Transceiver coil for auditory prosthesis

• US 20040044382A1
• Filed: 07/07/2003
• Published: 03/04/2004
• Est. Priority Date: 05/23/2001
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Ibrahim, Ibrahim Hanna
• Granted Patent: US 7,260,435 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61N 1/36036 of the outer, middle or inner ear
• CPC Class Codes: A61N 1/36038 Cochlear stimulation
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields

Abstract

The invention provides a tuned transmitter coil for transcutaneous transmission of power and information from an external component of an auditory prosthesis to an implanted receiver. A shield is provided in order to reduce a skin-to-coil capacitance, thereby improving tuning stability of the coil from one user to the next. A shield may also be provided in order to reduce electromagnetic interference.

Claims

1. A tuned transmitter coil for transcutaneous RF transmission of power and information from an external component of an auditory prosthesis to an implanted receiver, the transmitter coil comprising a first shield for reducing a skin-to-coil capacitance.

2. The tuned transmitter coil of claim 1 wherein the first shield is positioned relative to the transmitter coil such that, when the transmitter coil is brought close to a user'"'"'s skin for transcutaneous transmission of power and information, the first shield is positioned between the transmitter coil and the user'"'"'s skin.

3. The tuned transmitter coil of claim 1 or claim 2 wherein the first shield is integrally formed with the tuned transmitter coil.

4. The tuned transmitter coil of any preceding claim wherein the coil and shield are formed on a printed circuit board.

5. The tuned transmitter coil of claim 4 wherein the transmitter coil comprises first and second layers of the printed circuit board, each of the first and second layers comprising a respective track, each track defining a spiral with a plurality of turns.

6. The tuned transmitter coil of claim 5 wherein each respective spiral defined by the tracks of the first and second layers is generally circular.

7. The tuned transmitter coil of claim 5 or claim 6 wherein the dimensions of the track of each of the first and second layers are predetermined in order to control electrical performance of the coil.

8. The tuned transmitter coil of claim 7 wherein the number of turns of the spiral is predetermined in order to control electrical performance of the coil.

9. The tuned transmitter coil of claim 7 or claim 8 wherein the radial spacing between adjacent turns of the spiral is predetermined in order to control electrical performance of the coil.

10. The tuned transmitter coil of any one of claims 7 to 9 wherein a substrate of the printed circuit board is selected in order to control electrical performance of the coil.

11. The tuned transmitter coil of any one of claims 5 to 10 wherein each turn of the spiral of the first layer is placed adjacent to a respective gap between turns of the spiral of the second layer.

12. The tuned transmitter coil according to any one of claims 5 to 11 wherein the first shield is formed on a third layer of the printed circuit board integrally formed with the first and second layers of the printed circuit board.

13. The tuned transmitter coil according to claim 12 wherein the first shield is defined by tracks on the third layer, extending in a region adjacent to the spirals of the first and second layers.

14. The tuned transmitter coil according to claim 13 wherein the tracks defining the first shield are in the form of a plurality of substantially concentric open loops, and wherein each of the open loops are electrically grounded.

15. The tuned transmitter coil of claim 14 wherein the tracks defining the open loops of the first shield have a small width relative to a width of the tracks of the first and second layers.

16. The tuned transmitter coil of claim 14 or claim 15 wherein each open loop of the first shield is positioned adjacent to a gap between turns of the spiral of the adjacent layer.

17. The tuned transmitter coil according to any preceding claim and further comprising a second shield for reducing electromagnetic emissions from the transmitter coil.

18. The tuned transmitter coil according to claim 17 wherein the second shield is placed on a side of the transmission coil opposite to a side of the transmission coil on which the first shield is placed.

19. The tuned transmitter coil according to claim 17 or claim 18 wherein the second shield extends in a region substantially adjacent to the spirals of the first and second layers.

20. The tuned transmitter coil according to any one of claims 17 to 19, wherein the coil and first shield are formed on a printed circuit board, and wherein the second shield is defined by tracks on a fourth layer of the printed circuit board.

21. The tuned transmitter coil according to claim 20, wherein the tracks defining the second shield extend generally within a region adjacent to the turns of the spirals of the first and second layers.

22. The tuned transmitter coil according to claim 20 or claim 21 wherein the tracks defining the second shield are in the form of a plurality of substantially concentric open loops.

23. The tuned transmitter coil of claim 22 wherein each of the open loops are electrically grounded.

24. The tuned transmitter coil of any one of claims 20 to 23 wherein the tracks defining the second shield have a small width relative to a width of the tracks of the first and second layers.

25. The tuned transmitter coil of any one of claims 20 to 24 wherein the tracks defining the second shield are positioned adjacent to gaps between turns of the spiral of an adjacent layer of the PCB.

26. A transceiver for an auditory prosthesis, the transceiver comprising:

a tuned transmitter coil for transcutaneous transmissions, tuned to a desired frequency of transmission; and

a first shield for reducing a skin-to-coil capacitance.

27. The transceiver of claim 26 wherein the first shield is positioned relative to the transmitter coil such that, when the transmitter coil is brought close to a user'"'"'s skin for transcutaneous transmission of power and information, the first shield is positioned between the transmitter coil and the user'"'"'s skin.

28. The transceiver of claim 26 or claim 27 wherein the first shield is integrally formed with the tuned transmitter coil.

29. The transceiver of any one of claims 26 to 28 wherein the coil and shield are formed on a printed circuit board.

30. The transceiver of claim 29 wherein the transmitter coil comprises first and second layers of the printed circuit board, each of the first and second layers comprising a respective track, each track defining a spiral with a plurality of turns.

31. The transceiver of claim 30 wherein each respective spiral defined by the tracks of the first and second layers is generally circular.

32. The transceiver of claim 30 or claim 31 wherein the dimensions of the track of each of the first and second layers are predetermined in order to control electrical performance of the coil.

33. The transceiver of claim 32 wherein the number of turns of the spiral is predetermined in order to control electrical performance of the coil.

34. The transceiver of claim 32 or claim 33 wherein the radial spacing between adjacent turns of the spiral is predetermined in order to control electrical performance of the coil.

35. The transceiver of any one of claims 32 to 34 wherein a substrate of the printed circuit board is selected in order to control electrical performance of the coil.

36. The transceiver of any one of claims 30 to 35 wherein each turn of the spiral of the first layer is placed adjacent to a respective gap between turns of the spiral of the second layer.

37. The transceiver according to any one of claims 30 to 36 wherein the first shield is formed on a third layer of the printed circuit board integrally formed with the first and second layers of the printed circuit board.

38. The transceiver according to claim 37 wherein the first shield is defined by tracks on the third layer, extending in a region adjacent to the spirals of the first and second layers.

39. The transceiver according to claim 38 wherein the tracks defining the first shield are in the form of a plurality of substantially concentric open loops, and wherein each of the open loops are electrically grounded.

40. The transceiver of claim 39 wherein the tracks defining the open loops of the first shield have a small width relative to a width of the tracks of the first and second layers.

41. The transceiver of claim 39 or claim 40 wherein each open loop of the first shield is positioned adjacent to a gap between turns of the spiral of the adjacent layer.

42. The transceiver according to any one of claims 26 to 41 and further comprising a second shield for reducing electromagnetic emissions from the transmitter coil.

43. The transceiver according to claim 42 wherein the second shield is placed on a side of the transmission coil opposite to a side of the transmission coil on which the first shield is placed.

44. The transceiver according to claim 42 or claim 43 wherein the second shield extends in a region substantially adjacent to the spirals of the first and second layers.

45. The transceiver according to any one of claims 42 to 44, wherein the coil and first shield are formed on a printed circuit board, and wherein the second shield is defined by tracks on a fourth layer of the printed circuit board.

46. The transceiver according to claim 45, wherein the tracks defining the second shield extend generally within a region adjacent to the turns of the spirals of the first and second layers.

47. The transceiver according to claim 45 or claim 46 wherein the tracks defining the second shield are in the form of a plurality of substantially concentric open loops.

48. The transceiver of claim 47 wherein each of the open loops are electrically grounded.

49. The transceiver of any one of claims 45 to 48 wherein the tracks defining the second shield have a small width relative to a width of the tracks of the first and second layers.

50. The transceiver of any one of claims 45 to 49 wherein the tracks defining the second shield are positioned adjacent to gaps between turns of the spiral of an adjacent layer of the PCB.

51. An external processor unit for an auditory prosthesis, the external processor unit comprising:

a transceiver comprising a tuned transmitter coil for transcutaneous transmission, tuned to a desired frequency of transmission; and

a first shield for reducing a skin-to-coil capacitance.

52. The external processor unit of claim 51 wherein the first shield is positioned relative to the transmitter coil such that, when the transmitter coil is brought close to a user'"'"'s skin for transcutaneous transmission of power and information, the first shield is positioned between the transmitter coil and the user'"'"'s skin.

53. The external processor unit of claim 51 or claim 52 wherein the first shield is integrally formed with the tuned transmitter coil.

54. The external processor unit of any one of claims 51 to 53 wherein the coil and shield are formed on a printed circuit board.

55. The external processor unit of claim 54 wherein the transmitter coil comprises first and second layers of the printed circuit board, each of the first and second layers comprising a respective track, each track defining a spiral with a plurality of turns.

56. The external processor unit of claim 55 wherein each respective spiral defined by the tracks of the first and second layers is generally circular.

57. The external processor unit of claim 55 or claim 56 wherein the dimensions of the track of each of the first and second layers are predetermined in order to control electrical performance of the coil.

58. The external processor unit of claim 57 wherein the number of turns of the spiral is predetermined in order to control electrical performance of the coil.

59. The external processor unit of claim 57 or claim 58 wherein the radial spacing between adjacent turns of the spiral is predetermined in order to control electrical performance of the coil.

60. The external processor unit of any one of claims 57 to 59 wherein a substrate of the printed circuit board is selected in order to control electrical performance of the coil.

61. The external processor unit of any one of claims 55 to 60 wherein each turn of the spiral of the first layer is placed adjacent to a respective gap between turns of the spiral of the second layer.

62. The external processor unit according to any one of claims 55 to 61 wherein the first shield is formed on a third layer of the printed circuit board integrally formed with the first and second layers of the printed circuit board.

63. The external processor unit according to claim 62 wherein the first shield is defined by tracks on the third layer, extending in a region adjacent to the spirals of the first and second layers.

64. The external processor unit according to claim 63 wherein the tracks defining the first shield are in the form of a plurality of substantially concentric open loops, and wherein each of the open loops are electrically grounded.

65. The external processor unit of claim 64 wherein the tracks defining the open loops of the first shield have a small width relative to a width of the tracks of the first and second layers.

66. The external processor unit of claim 64 or claim 65 wherein each open loop of the first shield is positioned adjacent to a gap between turns of the spiral of the adjacent layer.

67. The external processor unit according to any one of claims 51 to 66 and further comprising a second shield for reducing electromagnetic emissions from the transmitter coil.

68. The external processor unit according to claim 67 wherein the second shield is placed on a side of the transmission coil opposite to a side of the transmission coil on which the first shield is placed.

69. The external processor unit according to claim 67 or claim 68 wherein the second shield extends in a region substantially adjacent to the spirals of the first and second layers.

70. The external processor unit according to any one of claims 67 to 69, wherein the coil and first shield are formed on a printed circuit board, and wherein the second shield is defined by tracks on a fourth layer of the printed circuit board.

71. The external processor unit according to claim 70, wherein the tracks defining the second shield extend generally within a region adjacent to the turns of the spirals of the first and second layers.

72. The external processor unit according to claim 70 or claim 71 wherein the tracks defining the second shield are in the form of a plurality of substantially concentric open loops.

73. The external processor unit of claim 72 wherein each of the open loops are electrically grounded.

74. The external processor unit of any one of claims 70 to 73 wherein the tracks defining the second shield have a small width relative to a width of the tracks of the first and second layers.

75. The external processor unit of any one of claims 70 to 74 wherein the tracks defining the second shield are positioned adjacent to gaps between turns of the spiral of an adjacent layer of the PCB.

76. An external processor unit for an auditory prosthesis, the external processor unit comprising:

a transmitter coil for transmission of transcutaneous electromagnetic signals to an implant;

a receiver for receiving wireless transmissions from a signal source; and

a shield for reducing electromagnetic emissions of the transmission coil.

77. The external processor unit of claim 76 wherein the coil and shield are formed on a printed circuit board.

78. The external processor unit of claim 77 wherein the transmitter coil comprises first and second layers of the printed circuit board, each of the first and second layers comprising a respective track, each track defining a spiral with a plurality of turns.

79. The external processor unit of claim 78 wherein each respective spiral defined by the tracks of the first and second layers is generally circular.

80. The external processor unit of claim 77 or claim 78 wherein the dimensions of the track of each of the first and second layers are predetermined in order to control electrical performance of the coil.

81. The external processor unit of claim 80 wherein the number of turns of the spiral is predetermined in order to control electrical performance of the coil.

82. The external processor unit of claim 80 or claim 81 wherein the radial spacing between adjacent turns of the spiral is predetermined in order to control electrical performance of the coil.

83. The external processor unit of any one of claims 80 to 82 wherein a substrate of the printed circuit board is selected in order to control electrical performance of the coil.

84. The external processor unit of any one of claims 80 to 83 wherein each turn of the spiral of the first layer is placed adjacent to a respective gap between turns of the spiral of the second layer.

85. The external processor unit according to claim 76 wherein the shield is placed relative to the transmitter coil such that when the transmitter coil is brought into proximity to a user'"'"'s skin for transcutaneous transmission, the transmitter coil is positioned between the user'"'"'s skin and the shield.

86. The external processor unit according to any one of claims 78 to 83 wherein the shield extends in a region substantially adjacent to the spirals of the first and second layers.

87. The external processor unit according to any one of claims 78 to 84, wherein the shield is defined by tracks on a fourth layer of the printed circuit board.

88. The external processor unit according to claim 87, wherein the tracks defining the shield extend generally within a region adjacent to the turns of the spirals of the first and second layers.

89. The external processor unit according to claim 87 or claim 88 wherein the tracks defining the shield are in the form of a plurality of substantially concentric open loops.

90. The external processor unit of claim 89 wherein each of the open loops are electrically grounded.

91. The external processor unit of any one of claims 87 to 90 wherein the tracks defining the shield have a small width relative to a width of the tracks of the first and second layers.

92. The external processor unit of any one of claims 87 to 91 wherein the tracks defining the shield are positioned adjacent to gaps between turns of the spiral of an adjacent layer of the PCB.

93. The external processor unit of any one of claims 76 to 92 wherein the external processor unit is adapted for mounting on a user'"'"'s ear.

94. The external processor unit of any one of claims 76 to 92 wherein the external processor unit is adapted for mounting on a user'"'"'s belt.

95. The external processor unit according to any one of claims 76 to 94 wherein the external processor unit comprises a cable to the transmission coil to allow the transmission coil to be placed behind a user'"'"'s ear, for coupling with an implant.

96. The ornamental design for a transmitter coil, as shown in FIG. 7.

97. An antenna for subcutaneous communication comprising at least one turn of a wire, the at least one turn being housed in a casing, wherein the casing comprises:

a cable inlet for accommodating a cable connection to the at least one turn;

an outer portion housing the at least one turn, wherein distal from the cable inlet the outer portion defines a substantially semicircular annulus following a nominal circumference of a nominal circle, wherein the cable inlet is positioned outside the nominal circumference, and wherein proximal to the cable inlet the outer portion extends substantially tangentially to the nominal circumference towards the cable inlet; and

an inner portion for housing magnetic means, the inner portion being connected to the outer portion proximal to the cable inlet, wherein the inner portion extends inside the nominal circle formed by the outer portion so as to position the magnetic means substantially at a centre of the nominal circle.

98. The antenna of claim 97 wherein the inner portion is integrally formed with the outer portion.

99. The antenna of claim 97 or claim 98 wherein the casing is formed of plastic.

100. The antenna of any one of claims 97 to 99 wherein, distal from the cable inlet, the outer portion takes the shape of a substantially rectangular cross-section annulus.

101. The antenna of any one of claims 97 to 100 wherein the inner portion is of a greater thickness than the outer portion, in a direction substantially perpendicular to a plane defined by the nominal circle.

102. The antenna of any one of claims 97 to 101, wherein the inner portion substantially extends only to one side of a plane defined by the nominal circle.