Electromagnetic interference immune tissue invasive system

• US 20020133200A1
• 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., Weiner, Michael L.
• Granted Patent: US 6,760,628 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. An implantable cable for the transmission of signals to and from a body tissue of a vertebrate, comprising:

a fiber optic lead having a surface of non-immunogenic, physiologically compatible material and being capable of being permanently implanted in a body cavity or subcutaneously;

said fiber optic lead having a distal end for implantation at or adjacent to the body tissue and a proximal end;

said fiber optic lead including a first optical fiber and a second optical fiber;

said first optical fiber having,

a proximal end coupled to an optical signal source, and

a distal end coupled to an optical stimulator;

said optical signal source generating an optical signal intended to cause said optical stimulator located at a distal end to deliver an excitatory stimulus to a selected body tissue, the stimulus being causing the selected body tissue to function as desired; and

said second optical fiber having,

a distal end coupled to a sensor, and

a proximal end coupled to a device responsive to an optical signal delivered by said second optical fiber;

said sensor generating an optical signal to represent a state of a function of the selected body tissue to provide feedback to affect the activity of said optical signal source.

2. The implantable cable as claimed in claim 1, wherein said optical stimulator in said first optical fiber including:

a photoresponsive device to convert the light transmitted by said first optical fiber 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 deliver an excitatory stimulus to a selected body tissue, the stimulus being causing the selected body tissue to function as desired.

3. The implantable cable as claimed in claim 2, wherein 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 first optical fiber into electrical energy.

4. The implantable cable as claimed in claim 2, 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 first optical fiber into electrical energy.

5. The implantable cable as claimed in claim 2, 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 first optical fiber into electrical energy.

6. The implantable cable as claimed in claim 5, wherein the first discharge period is completed before the second discharge period.

7. The implantable cable as claimed in claim 5, wherein the first discharge period is a shorter time duration that the time duration of the second discharge period.

8. The implantable cable as claimed in claim 5, wherein the integration period of said photoresponsive device corresponds to the sampling period of the light to derive control data.

9. The implantable cable as claimed in claim 5, 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.

10. The implantable cable as claimed in claim 2, wherein said charge accumulating device is a capacitor.

11. The implantable cable as claimed in claim 2, wherein said charge accumulating device is a rechargeable battery.

12. The implantable cable as claimed in claim 2, wherein said discharge control device is a controllable switch.

13. The implantable cable as claimed in claim 2, wherein said optical stimulator includes an electrode having an anti-antenna geometrical shape, said anti-antenna geometrical shape preventing said electrode from picking up and conducting stray electromagnetic interference.

14. The implantable cable as claimed in claim 2, wherein optical stimulator includes electrical pulsing components to deliver a stimulus of a predetermined duration and power to the selected body tissue.

15. The implantable cable as claimed in claim 2, wherein said optical stimulator includes an epicardial-lead to interface with a desired anatomical cardiac tissue region.

16. The implantable cable as claimed in claim 1, wherein said sensor detects physiological signals by measuring a displacement of a mirror.

17. The implantable cable as claimed in claim 1, wherein said sensor detects physiological signals by measuring a change in a refractive index of a section of cladding.

18. The implantable cable as claimed in claim 1, wherein said sensor is an optical strain gauge to detect physiological signals.

19. The implantable cable as claimed in claim 1, wherein said sensor is an optical-pressure sensor to detect physiological signals.

20. The implantable cable as claimed in claim 1, wherein said sensor includes a hollow porous sheath.

21. An implantable cable for the transmission of signals to and from a body tissue of a vertebrate, comprising:

a fiber optic lead having a surface of non-immunogenic, physiologically compatible material and being capable of being permanently implanted in a body cavity or subcutaneously;

said fiber optic lead having a distal end for implantation at or adjacent to the body tissue and a proximal end;

said proximal end of said fiber optic lead being coupled to an optical signal source and an optical device;

said distal end of said fiber optic lead being coupled to an optical stimulator and a sensor;

said optical signal source generating an optical signal intended to cause said optical stimulator located at a distal end to deliver an excitatory stimulus to a selected body tissue, the stimulus being causing the selected body tissue to function as desired;

said optical device being responsive to an optical signal generated by said sensor, the optical signal generated by said sensor representing a state of a function of the selected body tissue to provide feedback to affect the activity of said optical signal source.

22. The implantable cable as claimed in claim 21, wherein said optical stimulator including:

a photoresponsive device to convert the light transmitted by said fiber optic lead 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 deliver an excitatory stimulus to a selected body tissue, the stimulus being causing the selected body tissue to function as desired.

23. The implantable cable as claimed in claim 22, wherein 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 fiber optic lead into electrical energy.

24. The implantable cable as claimed in claim 22, 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 fiber optic lead into electrical energy.

25. The implantable cable as claimed in claim 22, 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 fiber optic lead into electrical energy.

26. The implantable cable as claimed in claim 25, wherein the first discharge period is completed before the second discharge period.

27. The implantable cable as claimed in claim 25, wherein the first discharge period is a shorter time duration that the time duration of the second discharge period.

28. The implantable cable as claimed in claim 25, wherein the integration period of said photoresponsive device corresponds to the sampling period of the light to derive control data.

29. The implantable cable as claimed in claim 25, 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.

30. The implantable cable as claimed in claim 22, wherein said charge accumulating device is a capacitor.

31. The implantable cable as claimed in claim 22, wherein said charge accumulating device is a rechargeable battery.

32. The implantable cable as claimed in claim 22, wherein said discharge control device is a controllable switch.

33. The implantable cable as claimed in claim 21, wherein said distal end of said fiber optic lead includes a fiber optic splitter.

34. The implantable cable as claimed in claim 21, wherein said proximal end of said fiber optic lead includes a fiber optic splitter.

35. The implantable cable as claimed in claim 21, wherein said distal end of said fiber optic lead includes a fiber optic splitter and said proximal end of said fiber optic lead includes a fiber optic splitter.

36. The implantable cable as claimed in claim 22, wherein said optical stimulator includes an electrode having an anti-antenna geometrical shape, said anti-antenna geometrical shape preventing said electrode from picking up and conducting stray electromagnetic interference.

37. The implantable cable as claimed in claim 22, wherein optical stimulator includes electrical pulsing components to deliver a stimulus of a predetermined duration and power to the selected body tissue.

38. The implantable cable as claimed in claim 22, wherein said optical stimulator includes an epicardial-lead to interface with a desired anatomical cardiac tissue region.

39. The implantable cable as claimed in claim 21, wherein said sensor detects physiological signals by measuring a displacement of a mirror.

40. The implantable cable as claimed in claim 21, wherein said sensor detects physiological signals by measuring a change in a refractive index of a section of cladding.

41. The implantable cable as claimed in claim 21, wherein said sensor is an optical strain gauge to detect physiological signals.

42. The implantable cable as claimed in claim 21, wherein said sensor is an optical-pressure sensor to detect physiological signals.

43. The implantable cable as claimed in claim 21, wherein said sensor includes a hollow porous sheath.