Double helical antenna assembly for a wireless intravascular medical device

• US 20060293718A1
• Filed: 06/24/2005
• Published: 12/28/2006
• Est. Priority Date: 06/24/2005
• Status: Active Grant

• Current Assignee: Kenergy, Inc.
• Original Assignee: Kenergy, Inc.
• Inventors: Denker, Stephen, Bulkes, Cherik, Beutler, Arthur J.
• Granted Patent: US 7,295,879 B2
• Time in Patent Office: Days
• US Class Current: 607/33
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/37516 Intravascular implants
• CPC Class Codes: A61N 1/37518 Anchoring of the implants, e.g. fixation

Abstract

A medical device, such as a cardiac pacing device for an animal, includes an intravascular antenna that has a first coil for engaging a wall of a first blood vessel to receive a radio frequency signal. The first coil includes a first winding wound helically in a rotational direction along a longitudinal axis from a first end of the coil to a second end. A second winding that is connected to the a first winding at the second end, is wound helically in the same rotational direction along the longitudinal axis from the second end to the first end. An electronic circuit is implanted in the animal and is connected to the antenna to receive an electrical signal therefrom.

Claims

1. A medical device comprising:

an antenna assembly having a first coil for engaging tissue inside an animal and for receiving a radio frequency signal, wherein the first coil has a first end and a second end spaced along a longitudinal axis, and includes a first winding wound helically from the first end to the second end, and a second winding connected to the a first winding at the second end and wound helically from the second end to the first end; and

an electronic circuit implanted in the animal and connected to the antenna assembly and receiving an electrical signal therefrom.

2. The medical device as recited in claim 1 wherein the first winding and the second winding are wound in one rotational direction around the longitudinal axis.

3. The medical device as recited in claim 1 wherein the first coil has only two windings.

4. The medical device as recited in claim 1 wherein the first winding and the second winding are each formed by a plurality of convolutions of a conductor, wherein both of the first winding and the second winding have a spacing between corresponding points on adjacent convolutions that is at least five times the width of the conductor.

5. The medical device as recited in claim 1 wherein the first coil is stretchable along the longitudinal axis which reduces the first coil diametrically for insertion into the animal, and is contractible along the longitudinal axis which causes diametric expansion to implant the first coil against the tissue of the animal.

6. The medical device as recited in claim 1 wherein the antenna assembly further comprises a detector connected to the first winding and the second winding for converting radio frequency signal into a direct current.

7. The medical device as recited in claim 1 wherein the antenna assembly is implanted into a first blood vessel of the animal, and the electronic circuit is implanted in a second blood vessel that is remote from the first blood vessel, and is connected to the antenna assembly by a conductor that extends through the first blood vessel and the second blood vessel.

8. The medical device as recited in claim 1 further comprising a power source for placement outside the animal, and having transmitter antenna and a transmitter that generates a radio frequency signal which is applied to the transmitter antenna.

9. The medical device as recited in claim 8 wherein the antenna assembly is located in a limb or an neck of the animal and the transmitter antenna is adjacent the limb or neck.

10. The medical device as recited in claim 9 wherein the transmitter antenna has a second coil that is wound around the limb or neck.

11. The medical device as recited in claim 8 wherein the transmitter antenna has a second coil that is wound along a given axis that is substantially parallel to the longitudinal axis of the first coil of the antenna assembly.

12. The medical device as recited in claim 1 wherein the coil is formed by a conductor with a non-circular cross section.

13. The medical device recited in claim 1 wherein the electronic circuit comprises:

a plurality of electrodes each in contact with tissue of the animal;

an electrical storage device for storing electrical energy from the radio frequency signal received by the antenna assembly;

a stimulation control circuit which determines when stimulation of tissue of the animal is needed; and

a pulse circuit which responds to the stimulation control circuit by applying voltage from the electrical storage device across the plurality of electrodes.

23. The medical device as recited in claim 1 wherein first coil is adapted to engage a wall of a blood vessel inside the animal.

14. A medical device comprising:

an antenna having a first coil for engaging a wall of a first blood vessel of an animal to receive a radio frequency signal, wherein the first coil has a first end and a second end, and includes a first winding wound helically in a rotational direction along a longitudinal axis from a first terminus at the first end to the second end, and a second winding connected to the a first winding at the second end and wound helically in the rotational direction along the longitudinal axis from the second end to a second terminus at the first end;

a detector connected to the first coil for converting the radio frequency signal into a direct current;

an electrical storage device connected to the detector for storing electrical energy;

a plurality of electrodes in contact with at least one blood vessel of the animal;

a stimulation control circuit which determines when stimulation of tissue of the animal is needed; and

a pulse circuit which responds to the stimulation control circuit by applying voltage from the electrical storage device across the plurality of electrodes.

15. The medical device as recited in claim 14 wherein the detector is located adjacent the antenna in the first blood vessel, and electronic circuit is implanted in a second blood vessel and is connected to the detector by a conductor that extends through the first blood vessel and the second blood vessel.

16. The medical device as recited in claim 14 further comprising a power source for placement outside the animal and having transmitter antenna and a transmitter that generates a radio frequency signal which is applied to the transmitter antenna.

17. The medical device as recited in claim 16 wherein the transmitter antenna has a second coil that is wound along a given axis that is substantially parallel to the longitudinal axis of the first coil of the antenna.

18. A medical device comprising:

an antenna assembly having a first coil for engaging a wall of a first blood vessel of an animal to receive a radio frequency signal

an electronic circuit implanted in the animal remotely from the first blood vessel and connected to the antenna assembly to receive an electrical signal therefrom; and

a power source for placement outside the animal and having transmitter antenna and a transmitter that generates a radio frequency signal which is applied to the transmitter antenna.

19. The medical device as recited in claim 18 wherein the first coil has a first end and a second end, and includes a first winding wound helically in a rotational direction about a longitudinal axis from a first terminus at the first end to the second end, and a second winding connected to the a first winding at the second end and wound helically in the rotational direction about the longitudinal axis from the second end to a second terminus at the first end.

20. The medical device as recited in claim 19 wherein the second coil that is wound along a given axis that is substantially parallel to the longitudinal axis of the first coil of the antenna assembly.

21. The medical device as recited in claim 18 wherein the first blood vessel, in which the antenna assembly, is located is in a limb or a neck of the animal;

and the transmitter antenna has a second coil that is wound around the limb or neck.

22. The medical device as recited in claim 18 wherein the antenna assembly further comprises a detector located adjacent and connected to first coil for converting radio frequency signal into a direct current.

24. A medical device for implantation into an animal, said medical device comprising:

an electronic circuit adapted for implanting into the animal; and

an antenna connected to the electronic circuit and having coil of electrically conductive material, wherein the coil has a collapsed state to enable insertion into the animal and an expanded state in which the coil engages tissue inside the animal to secure the antenna in place.

25. The medical device as recited in claim 24 wherein the coil of the antenna has a first end and a second end spaced along a longitudinal axis, and comprises a first winding wound helically from the first end to the second end, and a second winding connected to the a first winding at the second end and wound helically from the second end to the first end.

26. The medical device as recited in claim 25 wherein the first winding and the second winding are wound in one rotational direction around the longitudinal axis.

27. The medical device as recited in claim 25 wherein the first coil is stretchable along the longitudinal axis which reduces the first coil diametrically for insertion into the animal, and is contractible along the longitudinal axis which causes diametric expansion to implant the first coil into the tissue of the animal.