Systems for enabling telemetry in an implantable medical device

• US 7,720,544 B2
• Filed: 06/09/2006
• Issued: 05/18/2010
• Est. Priority Date: 06/09/2006
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Christman, Timothy J., Edwardson, Jason J., Carey, Bart A.
• Primary Examiner(s): Layno; Carl H
• Assistant Examiner(s): MALAMUD, DEBORAH LESLIE
• Application Number:
  US11/423,254
• Publication Number:
  US 20070288065A1
• Time in Patent Office: 1,439 Days
• Field of Search: 607 1- 2, 607/32, 607/36, 607/60, 343/718, 343/872, 343/873, 343/845, 128/903
• US Class Current: 607/60
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/3758 Packaging of the components within the casing
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

A system for enabling telemetry in implantable medical devices is provided. One aspect of this disclosure relates to an implantable medical device having radio-frequency telemetry capabilities. The device includes a housing and electronic circuitry contained within the housing. The device also includes an antenna connected to the electronic circuitry, the antenna having a helical portion and a whip portion, the whip portion separate from a feed conductor and adapted to enhance a radiation pattern of the antenna. According to various embodiments, the antenna and circuitry are adapted to facilitate transmission and reception of modulated radio-frequency energy at a specified carrier frequency. At least a portion of the antenna is embedded in a dielectric compartment, according to various embodiments. Other aspects and embodiments are provided herein.

Claims

1. An implantable medical device, comprising:

a telemetry circuit;

an implantable housing configured to contain at least a portion of the telemetry circuit;

an antenna electrically connected to the telemetry circuit at least in part using a feed, the antenna including a helical portion and a non-helical portion, the non-helical portion distinct from and electrically connected to the feed; and

wherein the antenna and telemetry circuit are configured to wirelessly transfer information using a specified range of frequencies when the implantable medical device is implanted, the range of frequencies determined at least in part by a physical arrangement of;

(1) the helical portion of the antenna with respect to at least one of the non-helical portion of the antenna or the housing;

or

(2) the non-helical portion of the antenna with respect to at least one of the helical portion of the antenna or the housing.

2. The device of claim 1, comprising a header mechanically attached to the housing, wherein the header includes a dielectric material, and wherein the antenna is substantially contained within the dielectric material.

3. The device of claim 2, wherein the header is configured to provide one or more electrical and mechanical connections to one or more implantable leads including one or more electrodes configured to deliver electrical therapy or to sense physiologic activity.

4. The device of claim 1, wherein the specified range of frequencies includes a range from about 300 MHz to about 1 GHz.

5. The device of claim 1, wherein the feed is configured to connect to the antenna at a specified location along the antenna, and wherein an input impedance of the antenna is determined at least in part by the specified location of the connection to the feed.

6. The device of claim 1, comprising:

a return structure included as a portion of the antenna, the return structure configured to provide a return path back to the telemetry circuit;

wherein the telemetry circuit supplies radio frequency energy to the antenna at the specified range of frequencies using the feed;

wherein at least a portion of the supplied radio frequency energy is returned to the telemetry circuit using the return structure; and

wherein the return structure includes a conductor located within the dielectric material, the conductor located at a specified distance from the housing at least in part to inhibit high-voltage arc-over during therapy delivery.

7. The device of claim 1, wherein an input impedance of the antenna within the specified range of frequencies is determined at least in part by a physical arrangement of the helical portion with respect to the non-helical portion.

8. The device of claim 1, wherein a radiation efficiency of the antenna within the specified range of frequencies is determined at least in part by a physical arrangement of the helical portion with respect to the non-helical portion.

9. The device of claim 1, wherein the specified range of frequencies is determined at least in part by the physical arrangement of the helical portion with respect to the non-helical portion.

10. The device of claim 1, wherein the specified range of frequencies is determined at least in part by the physical arrangement of the helical portion with respect to the housing.

11. The device of claim 1, wherein the specified range of frequencies is determined at least in part by the physical arrangement of the non-helical portion with respect to the housing.

12. An implantable medical device, comprising:

a telemetry circuit;

an implantable housing configured to contain at least a portion of the telemetry circuit;

a header mechanically attached to the housing;

a dielectric portion mechanically attached to the housing and located near the header;

an antenna electrically connected to the electronic circuitry, the antenna including a helical portion substantially contained within the header and a non-helical portion substantially contained within the dielectric portion;

wherein the antenna and telemetry circuit are configured to wirelessly transfer information using a specified range of frequencies when the implantable medical device is implanted, the range of frequencies determined at least in part by a physical arrangement of;

(1) the helical portion of the antenna with respect to at least one of the non-helical portion of the antenna or the housing;

or

(2) the non-helical portion of the antenna with respect to at least one of the helical portion of the antenna or the housing.

13. The device of claim 12, wherein the dielectric portion comprises a first dielectric material and the header comprises a second dielectric material.

14. The device of claim 13, wherein the first dielectric material is different than the second dielectric material.

15. The device of claim 13, wherein at least one of dielectric portion itself or the header itself includes more than one dielectric material.

16. The device of claim 15, wherein the dielectric portion includes a ceramic material configured to surround at least a portion of the antenna.

17. The device of claim 15, wherein the dielectric portion includes a region configured to provide a high-dielectric constant liquid configured to surround at least a portion of the antenna.

18. The device of claim 15, wherein at least one of the dielectric portion or the header includes an overmold dielectric material.

19. The device of claim 15, wherein at least one of the dielectric portion or the header includes one or more regions configured to be substantially filled with a medical adhesive backfill dielectric material.

20. The device of claim 12, wherein the helical portion of the antenna includes a metal wire wound around a bobbin.

21. The device of claim 20, wherein the bobbin has a dielectric core.

22. The device of claim 21, wherein the dielectric core includes a ceramic.

23. The device of claim 20 wherein the bobbin includes a region configured to provide a high-dielectric constant liquid surrounding at least a portion of the antenna.

24. The device of claim 12, wherein the specified range of frequencies is determined at least in part by the physical arrangement of the helical portion with respect to the non-helical portion.

25. The device of claim 12, wherein the specified range of frequencies is determined at least in part by the physical arrangement of the helical portion with respect to the housing.

26. The device of claim 12, wherein the specified range of frequencies is determined at least in part by the physical arrangement of the non-helical portion with respect to the housing.

27. The device of claim 12, wherein an input impedance of the antenna within the specified range of frequencies is determined at least in part by a physical arrangement of the helical portion with respect to the non-helical portion.

28. The device of claim 12, wherein a radiation efficiency of the antenna within the specified range of frequencies is determined at least in part by a physical arrangement of the helical portion with respect to the non-helical portion.

29. A method comprising:

providing a physical arrangement of a helical portion of an antenna and a non-helical portion of an antenna with respect to a housing of an implantable medical device;

providing an electrical connection between an antenna and a telemetry circuit at least partially contained within a housing of an implantable medical device, the antenna including a helical portion and a non-helical portion; and

transferring information wirelessly using the antenna and the telemetry circuit, the transferring using a specified range of frequencies determined at least in part by a physical arrangement of;

(1) the helical portion of the antenna with respect to at least one of the non-helical portion of the antenna or the housing;

or

(2) the non-helical portion of the antenna with respect to at least one of the helical portion of the antenna or the housing.

30. The method of claim 29, wherein the transferring information includes using a specified range of frequencies determined at least in part by the physical arrangement of the helical portion with respect to the non-helical portion.

31. The method of claim 29, comprising controlling an input impedance of the antenna within the specified range of frequencies at least in part using a physical arrangement of the helical portion of the antenna with respect to the non-helical portion.

32. The method of claim 29, comprising controlling a radiation efficiency of the antenna within the specified range of frequencies at least in part using a physical arrangement of the helical portion of the antenna with respect to the non-helical portion.

33. The method of claim 29, wherein the transferring information includes using a specified range of frequencies determined at least in part by the physical arrangement of the helical portion with respect to the housing.

34. The method of claim 29, wherein the transferring information includes using a specified range of frequencies determined at least in part by the physical arrangement of the non-helical portion with respect to the housing.