Implantable medical device with air core antenna assembly

• US 20040082977A1
• Filed: 10/25/2002
• Published: 04/29/2004
• Est. Priority Date: 10/25/2002
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Engmark, David B., Nicholson, John E., Reinker, David M., Child, Brian S.
• Granted Patent: US 6,931,284 B2
• Time in Patent Office: Days
• US Class Current: 607/36
• CPC Class Codes: A61N 1/372 Arrangements in connection with the implantation of stimulators
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/3758 Packaging of the components within the casing

Abstract

An implantable medical device that includes an enclosure, an electrical module for the desired stimulation, sensing and communications functions, a power source, an air-core antenna, and supporting structures therefore. The antenna includes a quarter-elliptical shape that maximizes the antenna area to facilitate transmission of electromagnetic waves through the enclosure. A support structure is provided so that the antenna, the module and the battery self-align with each other and the enclosure. The support structure contains contacts to facilitate electrical connection of the antenna to the module and positions the module so that contacts thereon are in close proximity in plan and elevation to external electrical feed-throughs in the housing and the antenna contacts on the support structure. The support structure positions the antenna between the module and the housing, separated therefrom by a predetermined minimum distance to facilitate efficient coupling of electromagnetic waves to and/or from the antenna.

Claims

1. An implantable medical device for electrically interacting with a surrounding body, comprising:

an enclosure at least partially transparent to electromagnetic waves and having an inner surface, within which are an energy source and electrical circuitry coupled to the energy source for providing or receiving electrical signals to or from the body;

a multi-layer air-core antenna located within the enclosure and electrically coupled to the electrical circuitry for sending or receiving electromagnetic waves through the enclosure; and

a first support member for retaining the antenna in predetermined relation to the enclosure and the electrical circuitry.

2. The device of claim 1 wherein the support member includes an outer surface that conforms at least in part to a portion of the inner surface of the enclosure.

3. The device of claim 1 wherein the support member includes electrical contacts for receiving connections from the antenna and the electrical circuitry to electrically couple the antenna and an electrical circuitry.

4. The device of claim 1 wherein the support member further comprises a first portion for retaining the antenna in predetermined relation thereto and a second portion for spacing a surface of the antenna a predetermined distance from the inner surface of the enclosure.

5. The device of claim 4 wherein the predetermined distance is approximately greater than or equal to 0.6 mm.

6. The device of claim 1 wherein the antenna includes a substantially quarter-elliptical plan view shape.

7. The device of claim 1 further comprising a second support member for receiving the energy source, wherein the first and second support members include mating structural alignment regions.

8. The device of claim 7 wherein the first and second support members position the electrical circuitry, the antenna and the energy source in predetermined relationship.

9. The device of claim 1 wherein the antenna, the first support member and the electrical circuitry include substantially quarter-elliptical plan view shapes.

10. The device of claim 1 wherein the electrical circuitry is mounted on a substrate and the first insulating member aligns the antenna with respect to the enclosure and aligns the substrate with respect to the antenna, to thereby maintain predetermined minimum spacings between the substrate, the antenna and the enclosure, and the antenna being positioned substantially between the substrate and the enclosure.

11. The device of claim 10 wherein the minimum spacings include dimensions of approximately 0.6 mm or larger.

12. An implantable device comprising a sealable housing, an electronic module, a multi-layer air-core antenna electrically coupled to the module, and a first support cup for locating both the module and the antenna within the housing, the first cup having a first portion for receiving the antenna in spaced-apart relationship to the housing and a second portion for receiving the module in spaced-apart relationship to the antenna to thereby position the module substantially superimposed over the antenna.

13. The device of claim 12 wherein the first cup, the module and the antenna include substantially quarter-elliptical plan view shapes.

14. The device of claim 12 wherein a plane of the antenna is positioned a first minimum distance from a plane of the housing and a second minimum distance from a plane of the module, and the first and second minimum distances approximately 0.7 mm.

15. The device of claim 12 further comprising an energy source within the housing and a second insulating cup for positioning the energy source in spaced-apart relationship from the housing, wherein the first and second cups include corresponding mating regions wherein the first and second cups align with respect to each other within the housing.

16. The device of claim 12 wherein the housing further comprises first electrical connections extending through the housing and the module further comprises second electrical connections, wherein the first cup positions the module and the antenna within the housing in a predetermined arrangement wherein the first and second connections include substantially proximate structural arrangement.

17. The device of claim 16 wherein the first cup comprises electrical connections having first portions for receiving electrical connections from the antenna and second portions for receiving electrical connections from the module, and wherein a first outer surface of the second portions and a second outer surface of the second electrical structures include approximately co-planar connections.

18. An implantable device comprising a housing, an electronic module, an air-core antenna electrically coupled to the module, and an insulating cup for locating both the module and the antenna within the housing, the cup having a first portion for receiving the antenna in spaced-apart relationship to the housing and a second portion for receiving the module in spaced-apart relationship to the antenna, wherein the antenna includes a multi-turn coil comprising a total area and an interior air-core area, wherein the air-core area includes greater than half of the total area.

19. The device of claim 18 wherein the module and a first interior surface of the housing include a structural arrangement of the antenna located substantially therebetween.