Electromagnetic interference immune tissue invasive system

• US 20020133199A1
• Filed: 02/19/2002
• Published: 09/19/2002
• Est. Priority Date: 02/20/2001
• Status: Active Grant

• Current Assignee: Biophan Technologies Incorporated
• Original Assignee: Biophan Technologies Incorporated
• Inventors: MacDonald, Stuart G., Connelly, Patrick R.
• Granted Patent: US 6,763,268 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: A61N 1/37512 Pacemakers
• 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

Abstract

An electromagnetic immune tissue invasive system includes a primary device housing. The primary device housing having a control circuit therein. A shielding is formed around the primary device housing to shield the primary device housing and any circuits therein from electromagnetic interference. A lead system transmits and receives signals between the primary device housing. The lead system is either a fiber optic system or an electrically shielded electrical lead system.

Claims

1. A cardiac assist device, comprising:

a primary device housing;

said primary device housing having a control circuit therein;

a shielding formed around said primary device housing to shield said primary device housing and any circuits therein from electromagnetic interference;

a lead system to transmit and receive signals between a selected cardiac tissue region and said primary device housing;

a switch to place the control circuitry into a fixed-rate mode of operation;

an acoustic sensor to sense a predetermined acoustic signal;

said switch placing the control circuitry into a fixed-rate mode of operation when said acoustic sensor senses the predetermined acoustic signal.

2. The cardiac assist device as claimed in claim 1, wherein said shielding is a metallic sheath to shield said primary device housing and any circuits therein from electromagnetic interference.

3. The cardiac assist device as claimed in claim 1, wherein said shielding is a carbon composite sheath to shield said primary device housing and any circuits therein from electromagnetic interference.

4. The cardiac assist device as claimed in claim 1, wherein said shielding is a polymer composite sheath to shield said primary device housing and any circuits therein from electromagnetic interference.

5. The cardiac assist device as claimed in claim 1, wherein said lead system comprises a fiber optic based communication system.

6. The cardiac assist device as claimed in claim 5, wherein said fiber optic communication system contains at least one channel within a multi-fiber optic bundle.

7. The cardiac assist device as claimed in claim 1, wherein said lead system comprises a plurality of electrical leads.

8. The cardiac assist device as claimed in claim 7, wherein said plurality of electrical leads have a second shielding therearound, said second shielding preventing said electrical leads from conducting stray electromagnetic interference.

9. The cardiac assist device as claimed in claim 8, wherein said second shielding is a metallic sheath to prevent said electrical leads from conducting stray electromagnetic interference.

10. The cardiac assist device as claimed in claim 8, wherein said second shielding is a carbon composite sheath to prevent said electrical leads from conducting stray electromagnetic interference.

11. The cardiac assist device as claimed in claim 8, wherein said second shielding is a polymer composite sheath to prevent said electrical leads from conducting stray electromagnetic interference.

12. The cardiac assist device as claimed in claim 7, wherein each electrical lead includes an electrical filter, said electrical filter removing stray electromagnetic interference from a signal being received from said electrical lead.

13. The cardiac assist device as claimed in claim 12, wherein said plurality of electrical leads have a second shielding therearound, said second shielding preventing said electrical leads from conducting stray electromagnetic interference.

14. The cardiac assist device as claimed in claim 13, wherein said second shielding is a carbon composite sheath to prevent said electrical leads from conducting stray electromagnetic interference.

15. The cardiac assist device as claimed in claim 13, wherein said second shielding is a polymer composite sheath to prevent said electrical leads from conducting stray electromagnetic interference.

16. The cardiac assist device as claimed in claim 1, wherein said shielding is covered with a biocompatible material.

17. The cardiac assist device as claimed in claim 5, wherein said fiber optic based communication system is covered with a biocompatible material.

18. The cardiac assist device as claimed in claim 6, wherein said multi-fiber optic bundle is covered with a biocompatible material.

19. The cardiac assist device as claimed in claim 1, wherein said primary device housing includes a microprocessor integrated circuit for controlling the operations of the cardiac assist device.

20. The cardiac assist device as claimed in claim 19, further comprising a battery power source and a battery power source measuring circuit;

said microprocessor integrated circuit automatically adjusting a value for determining an elective replacement indication condition of a battery power source such that the value is automatically adjusted by said microprocessor integrated circuit in response to a measured level of a state of said battery power source, the measured level generated by said battery power source measuring circuit connected to said battery power source.

21. The cardiac assist device as claimed in claim 19, wherein said microprocessor integrated circuit isolates physiological signals using a noise filtering circuit.

22. The cardiac assist device as claimed in claim 19, wherein said microprocessor integrated circuit isolates physiological signals using digital noise filtering.

23. The cardiac assist device as claimed in claim 19, wherein said microprocessor integrated circuit is programmable from a source external of the cardiac assist device.

24. The cardiac assist device as claimed in claim 19, wherein said microprocessor integrated circuit provides physiological diagnostics to a source external of the cardiac assist device.

25. The cardiac assist device as claimed in claim 19, wherein said microprocessor integrated circuit provides circuit diagnostics to a source external of the cardiac assist device.

26. The cardiac assist device as claimed in claim 19, wherein said microprocessor integrated circuit is programmable from a source external of the cardiac assist device and provides circuit diagnostics to a source external of the cardiac assist device.

27. The cardiac assist device as claimed in claim 1, wherein said leads system is a combination of a fiber optic based communication system and electrical leads.

28. The cardiac assist device as claimed in claim 27, wherein said fiber optic communication system contains at least one channel within a multi-fiber optic bundle.

29. The cardiac assist device as claimed in claim 1, wherein said lead system includes a sensing and stimulation system at an interface with the selected cardiac tissue region.

30. The cardiac assist device as claimed in claim 29, wherein said sensing and stimulation system includes optical sensing components to detect physiological signals from the selected cardiac tissue region.

31. The cardiac assist device as claimed in claim 29, wherein said sensing and stimulation system includes optical sensing components to detect physiological signals from the desired anatomical cardiac tissue region and electrical sensing components to detect physiological signals from the selected cardiac tissue region.

32. The cardiac assist device as claimed in claim 29, wherein said sensing and stimulation system includes electrical sensing components to detect physiological signals from the selected cardiac tissue region.

33. The cardiac assist device as claimed in claim 29, wherein said sensing and stimulation system includes optical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region.

34. The cardiac assist device as claimed in claim 30, wherein said sensing and stimulation system includes optical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region.

35. The cardiac assist device as claimed in claim 29, wherein said sensing and stimulation system includes optical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region and electrical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region.

36. The cardiac assist device as claimed in claim 30, wherein said sensing and stimulation system includes optical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region and electrical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region.

37. The cardiac assist device as claimed in claim 1, wherein said lead system is a photonic lead system to transmit between said primary device housing and the selected cardiac tissue region, both power and control signals in the form of light, and further comprising:

a photoresponsive device to convert the light transmitted by said photonic lead system into electrical energy and to sense variations in the light energy to produce control signals;

a charge accumulating device to receive and store the electrical energy produced by said photoresponsive device; and

a discharge control device, responsive to the control signals, to direct the stored electrical energy from said charge accumulating device to the selected cardiac tissue region.

38. The cardiac assist system as claimed in claim 1, further comprising:

a detection circuit to detect a phase timing of an external electromagnetic field;

said control circuit altering its operations to avoid interfering with the detected external electromagnetic field.

39. The cardiac assist system as claimed in claim 37, wherein said photoresponsive device is a small surface area photodiode and a large surface area photodiode, said small surface area photodiode sensing variations in the light energy to produce control signals, said large surface area photodiode converting the light transmitted by said photonic lead system into electrical energy.

40. The cardiac assist system as claimed in claim 37, wherein said photoresponsive device is an array of photodiodes having a first section of photodiodes and a second section of photodiodes, said first section of photodiodes sensing variations in the light energy to produce control signals, said second section of photodiodes converting the light transmitted by said photonic lead system into electrical energy.

41. The cardiac assist system as claimed in claim 37, wherein said photoresponsive device includes a charge transfer control circuit and a photodiode, said charge transfer control circuit controlling a discharging of a photodiode capacitance in two separate discharge periods during an integration period of the photodiode such that a first discharge period of the photodiode capacitance provides the sensing of variations in the light energy to produce control signals and a second discharge period of the photodiode capacitance provides the converting the light transmitted by said photonic lead system into electrical energy.

42. The cardiac assist system as claimed in claim 41, wherein the first discharge period is completed before the second discharge period.

43. The cardiac assist system as claimed in claim 41, wherein the first discharge period is a shorter time duration that the time duration of the second discharge period.

44. The cardiac assist system as claimed in claim 41, wherein the integration period corresponds to the sampling period of the light to derive control data.

45. The cardiac assist system as claimed in claim 41, wherein during the first discharge period, a control signal sensing circuit is connected to said photodiode, and during the second discharge period, said charge accumulating device is connected to said photodiode.

49. The cardiac assist system as claimed in claim 37, wherein said charge accumulating device is a capacitor.

50. The cardiac assist system as claimed in claim 37, wherein said charge accumulating device is a rechargeable battery.

51. The cardiac assist system as claimed in claim 37, wherein said discharge control device is a controllable switch.

100. The cardiac assist system as claimed in claim 1, wherein said switch is a reed switch.

101. The cardiac assist system as claimed in claim 1, wherein said switch is a solid-state switch.

52. A cardiac assist system, comprising:

a primary device housing;

said primary device housing having a control circuit therein;

a shielding formed around said primary device housing to shield said primary device housing and any circuits therein from electromagnetic interference;

a lead system to transmit and receive signals between a selected cardiac tissue region and said primary device housing;

a switch to place the control circuitry into a fixed-rate mode of operation;

a near infrared sensor to sense a predetermined near infrared signal;

said switch placing the control circuitry into a fixed-rate mode of operation when said near infrared sensor senses the predetermined near infrared signal.

53. The cardiac assist device as claimed in claim 52, wherein said shielding is a metallic sheath to shield said primary device housing and any circuits therein from electromagnetic interference.

54. The cardiac assist device as claimed in claim 52, wherein said shielding is a carbon composite sheath to shield said primary device housing and any circuits therein from electromagnetic interference.

55. The cardiac assist device as claimed in claim 52, wherein said shielding is a polymer composite sheath to shield said primary device housing and any circuits therein from electromagnetic interference.

56. The cardiac assist device as claimed in claim 52, wherein said lead system comprises a fiber optic based communication system.

57. The cardiac assist device as claimed in claim 56, wherein said fiber optic communication system contains at least one channel within a multi-fiber optic bundle.

58. The cardiac assist device as claimed in claim 52, wherein said lead system comprises a plurality of electrical leads.

59. The cardiac assist device as claimed in claim 58, wherein said plurality of electrical leads have a second shielding therearound, said second shielding preventing said electrical leads from conducting stray electromagnetic interference.

60. The cardiac assist device as claimed in claim 59, wherein said second shielding is a metallic sheath to prevent said electrical leads from conducting stray electromagnetic interference.

61. The cardiac assist device as claimed in claim 59, wherein said second shielding is a carbon composite sheath to prevent said electrical leads from conducting stray electromagnetic interference.

62. The cardiac assist device as claimed in claim 59, wherein said second shielding is a polymer composite sheath to prevent said electrical leads from conducting stray electromagnetic interference.

63. The cardiac assist device as claimed in claim 58, wherein each electrical lead includes an electrical filter, said electrical filter removing stray electromagnetic interference from a signal being received from said electrical lead.

64. The cardiac assist device as claimed in claim 63, wherein said plurality of electrical leads have a second shielding therearound, said second shielding preventing said electrical leads from conducting stray electromagnetic interference.

65. The cardiac assist device as claimed in claim 64, wherein said second shielding is a carbon composite sheath to prevent said electrical leads from conducting stray electromagnetic interference.

66. The cardiac assist device as claimed in claim 64, wherein said second shielding is a polymer composite sheath to prevent said electrical leads from conducting stray electromagnetic interference.

67. The cardiac assist device as claimed in claim 52, wherein said shielding is covered with a biocompatible material.

68. The cardiac assist device as claimed in claim 56, wherein said fiber optic based communication system is covered with a biocompatible material.

69. The cardiac assist device as claimed in claim 57, wherein said multi-fiber optic bundle is covered with a biocompatible material.

70. The cardiac assist device as claimed in claim 52, wherein said primary device housing includes a microprocessor integrated circuit for controlling the operations of the cardiac assist device.

71. The cardiac assist device as claimed in claim 70, further comprising a battery power source and a battery power source measuring circuit;

said microprocessor integrated circuit automatically adjusting a value for determining an elective replacement indication condition of a battery power source such that the value is automatically adjusted by said microprocessor integrated circuit in response to a measured level of a state of said battery power source, the measured level generated by said battery power source measuring circuit connected to said battery power source.

72. The cardiac assist device as claimed in claim 70, wherein said microprocessor integrated circuit isolates physiological signals using a noise filtering circuit.

73. The cardiac assist device as claimed in claim 70, wherein said microprocessor integrated circuit isolates physiological signals using digital noise filtering.

74. The cardiac assist device as claimed in claim 70, wherein said microprocessor integrated circuit is programmable from a source external of the cardiac assist device.

75. The cardiac assist device as claimed in claim 70, wherein said microprocessor integrated circuit provides physiological diagnostics to a source external of the cardiac assist device.

76. The cardiac assist device as claimed in claim 70, wherein said microprocessor integrated circuit provides circuit diagnostics to a source external of the cardiac assist device.

77. The cardiac assist device as claimed in claim 70, wherein said microprocessor integrated circuit is programmable from a source external of the cardiac assist device and provides circuit diagnostics to a source external of the cardiac assist device.

78. The cardiac assist device as claimed in claim 52, wherein said leads system is a combination of a fiber optic based communication system and electrical leads.

79. The cardiac assist device as claimed in claim 78, wherein said fiber optic communication system contains at least one channel within a multi-fiber optic bundle.

80. The cardiac assist device as claimed in claim 52, wherein said lead system includes a sensing and stimulation system at an epicardial-lead interface with the selected cardiac tissue region.

81. The cardiac assist device as claimed in claim 78, wherein said sensing and stimulation system includes optical sensing components to detect physiological signals from the selected cardiac tissue region.

82. The cardiac assist device as claimed in claim 80, wherein said sensing and stimulation system includes optical sensing components to detect physiological signals from the desired anatomical cardiac tissue region and electrical sensing components to detect physiological signals from the selected cardiac tissue region.

83. The cardiac assist device as claimed in claim 80, wherein said sensing and stimulation system includes electrical sensing components to detect physiological signals from the selected cardiac tissue region.

84. The cardiac assist device as claimed in claim 80, wherein said sensing and stimulation system includes optical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region.

85. The cardiac assist device as claimed in claim 81, wherein said sensing and stimulation system includes optical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region.

86. The cardiac assist device as claimed in claim 80, wherein said sensing and stimulation system includes optical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region and electrical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region.

87. The cardiac assist device as claimed in claim 81, wherein said sensing and stimulation system includes optical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region and electrical pulsing components to deliver a stimulus of a predetermined duration and power to the selected cardiac tissue region.

88. The cardiac assist device as claimed in claim 52, wherein said lead system is a photonic lead system to transmit between said primary device housing and the selected cardiac tissue region, both power and control signals in the form of light, and further comprising:

a photoresponsive device to convert the light transmitted by said photonic lead system into electrical energy and to sense variations in the light energy to produce control signals;

a charge accumulating device to receive and store the electrical energy produced by said photoresponsive device; and

a discharge control device, responsive to the control signals, to direct the stored electrical energy from said charge accumulating device to the selected cardiac tissue region.

89. The cardiac assist system as claimed in claim 52, further comprising:

a detection circuit to detect a phase timing of an external electromagnetic field;

said control circuit altering its operations to avoid interfering with the detected external electromagnetic field.

90. The cardiac assist system as claimed in claim 88, wherein said photoresponsive device is a small surface area photodiode and a large surface area photodiode, said small surface area photodiode sensing variations in the light energy to produce control signals, said large surface area photodiode converting the light transmitted by said photonic lead system into electrical energy.

91. The cardiac assist system as claimed in claim 88, wherein said photoresponsive device is an array of photodiodes having a first section of photodiodes and a second section of photodiodes, said first section of photodiodes sensing variations in the light energy to produce control signals, said second section of photodiodes converting the light transmitted by said photonic lead system into electrical energy.

92. The cardiac assist system as claimed in claim 88, wherein said photoresponsive device includes a charge transfer control circuit and a photodiode, said charge transfer control circuit controlling a discharging of a photodiode capacitance in two separate discharge periods during an integration period of the photodiode such that a first discharge period of the photodiode capacitance provides the sensing of variations in the light energy to produce control signals and a second discharge period of the photodiode capacitance provides the converting the light transmitted by said photonic lead system into electrical energy.

93. The cardiac assist system as claimed in claim 92, wherein the first discharge period is completed before the second discharge period.

94. The cardiac assist system as claimed in claim 92, wherein the first discharge period is a shorter time duration that the time duration of the second discharge period.

95. The cardiac assist system as claimed in claim 92, wherein the integration period corresponds to the sampling period of the light to derive control data.

96. The cardiac assist system as claimed in claim 92, wherein during the first discharge period, a control signal sensing circuit is connected to said photodiode, and during the second discharge period, said charge accumulating device is connected to said photodiode.

97. The cardiac assist system as claimed in claim 88, wherein said charge accumulating device is a capacitor.

98. The cardiac assist system as claimed in claim 88, wherein said charge accumulating device is a rechargeable battery.

99. The cardiac assist system as claimed in claim 88, wherein said discharge control device is a controllable switch.

102. The cardiac assist system as claimed in claim 52, wherein said switch is a reed switch.

103. The cardiac assist system as claimed in claim 52, wherein said switch is a solid-state switch.