Telemetry system for implantable medical devices

• US 6,169,925 B1
• Filed: 04/30/1999
• Issued: 01/02/2001
• Est. Priority Date: 04/30/1999
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Dublin, Garry L., Villaseca, Eduardo H., Haubrich, Gregory J., Goedeke, Steven D.
• Primary Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US09/302,932
• Time in Patent Office: 613 Days
• Field of Search: 607/32, 607/60, 128/703
• US Class Current: 607/60
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

A device for use in communication with an implantable medical device. The device is provided with a spatial diversity antenna array mounted to a housing and an RF transceiver operating at defined frequency, coupled to the antenna alray. The antenna array comprises two antennas spaced a fraction of the wavelength of the defined frequency from one another, each antenna including two antenna elements mounted to the housing and located oithogonal to one another. Selection of which of the antennas is employed is accomplished by an device controller, responsive to the quality of the signals received by the antennas.

Claims

1. An external device for use in communication with an implantable medical device, comprising:

a device controller;

a housing;

an antenna array mounted to the housing;

an RF transceiver operating at defined frequency, coupled to the antenna array;

means for encoding signals to be transmitted to the implantable device, coupled to an input of the transceiver;

means for decoding signals received from the implantable device, coupled to an output of the transceiver; and

means for displaying the decoded signals received from the implantable device;

wherein the antenna array comprises two antennas spaced a fraction of the wavelength of the defined frequency from one another, each antenna comprising two antenna elements mounted to the housing and located orthogonal to one another; and

wherein the device controller includes means for selecting which of the two antennas is coupled to the transceiver.

2. A device according to claim 1 wherein a portion of the housing is conductive and each antenna comprises two tuned stub antenna elements having major axes orthogonal to one another, mounted to and extending from the conductive portion of the housing.

3. A device according to claim 2 wherein the major axis of each tuned stub element in one of the antennas is generally coplanar to the major axis of one of the stub elements in the other of the antennas.

4. A device according to claim 2 wherein the major axis of each tuned stub element in one of the antennas is generally parallel to the major axis of one of the stub elements in the other of the antennas.

5. A device according to claim 1 wherein at least a portion of the housing is non-conductive and each antenna comprises two generally planar conductive antenna elements mounted to the non-conductive portion of the housing and located generally along two mutually orthogonal planes.

6. A device according to claim 5 wherein the antenna elements are mounted along surfaces of the housing.

7. A device according to claim 5 wherein the antenna elements are metal strips or sheets adhered to surfaces of the housing.

8. A device according to any of claims 1-7 wherein the two antenna elements are coupled to one another by means of a 180 degree splitter.

9. A device according to claim 8 wherein the transceiver is a UHF transceiver.

10. A device according to any of claims 1-7 wherein the transceiver is a UHF transceiver.

11. A system comprising an external device and an associated implantable device, wherein the external device comprises:

a device controller;

a housing;

an antenna array mounted to the housing;

an RF transceiver operating at defined frequency, coupled to the antenna array;

means for encoding signals to be transmitted to the implantable device, coupled to an input of the transceiver;

means for decoding signals received from the implantable device, coupled to an output of the transceiver; and

means for displaying the decoded signals received from the implantable device, mounted to the housing;

wherein the antenna array comprises two antennas spaced a fraction of the wavelength of the defined frequency from one another, each antenna comprising two antenna elements mounted to the housing and located orthogonal to one another; and

wherein the device controller includes means for selecting which of the two antennas is coupled to the transceiver; and

wherein the implantable device comprises;

a hermetic housing;

a transceiver mounted within the hermetic housing;

a first feedthrough, mounted to the housing and coupled to the transceiver; and

an implantable antenna located external to the housing and coupled to the first feedthrough, the implantable antenna comprising a length of insulated conductor extending from the first feedthrough.

12. A system according to claim 11 wherein the implantable antenna comprises a metallic tab having first and second ends, the first end coupled to the first feedthrough an the second end coupled to the length of insulated conductor.

13. A system according to claim 12 wherein the implantable device comprises a non-conductive header mounted to the housing, wherein the metallic tab is mounted to the header.

14. A system according to claim 13 wherein the tab is mounted within the header.

15. A system according to claim 13 wherein the length of insulated conductor extends external to the header.

16. A device according to claim 12 wherein the tab is formed of a metal sheet and wherein the-second end of the tab has a width greater than the first end of the tab.

17. A system according to claim 12 wherein the implantable devices comprises a second feedthrough and wherein the header comprises means for connecting a medical electrical lead to the second feedthrough.

18. A system according to claim 11 wherein the implantable antenna comprises the length of conductor encased in a dielectric, extending from the first feedthrough, and a coaxial shield coupled to the housing and extending along only a portion of the length of conductor.

19. A system according to claim 18 comprising a non-conductive header mounted to the housing, wherein the coaxial shield is mounted to the header.

20. A device according to claim 19 wherein the coaxial shield is mounted within the header.

21. A system according to claim 18 wherein the implantable device comprises a second feedthrough and wherein the header comprises means for connecting a medical electrical lead to the second feedthrough.

22. A system according to any of claims 12 to 21 wherein the implantable transceiver is a UHF transceiver.

23. A system according to any of claims 12 to 21 wherein a portion of the external device housing is conductive and each external antenna comprises two tuned stub antenna elements having major axes orthogonal to one another, mounted to an extending from a conductive portion of the housing.

24. A system according to claim 23 wherein the major axis of each tuned stub element in one of the antennas is generally coplanar to the major axis of one of the stub elements in the other of the antennas.

25. A system according to claim 23 wherein the major axis of each tuned stub element in one of the antennas is generally parallel to the major axis of one of the stub elements in the other of the antennas.

26. A system according to claim 23 wherein the two antenna elements are coupled to one another by means of a 180 degree splitter.

27. A system according to any of claims 12 to 21 wherein a portion of the external housing is non-conductive and each external antenna comprises two generally planar conductive antenna elements mounted to a non-conductive portion of the housing and located generally along two mutually orthogonal planes.

28. A system according to claim 27 wherein the antenna elements are mounted along surfaces of the housing.

29. A system according to claim 28 wherein the antenna elements are metal strips or sheets adhered to surfaces of the housing.

30. A system according to any of claim 27 wherein the two antenna elements are coupled to one another by means of a 180 degree splitter.