ANTENNA ON CERAMIC CASE

• US 20070260294A1
• Filed: 05/05/2006
• Published: 11/08/2007
• Est. Priority Date: 05/05/2006
• Status: Active Grant

• Current Assignee: Alfred E. Mann Foundation For Scientific Research
• Original Assignee: Alfred E. Mann Foundation For Scientific Research
• Inventors: Schulman, Joseph, Stover, Howard, Lasater, Brian
• Granted Patent: US 7,908,014 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• 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 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

The invention is an antenna for use with an implantable microdevice, such as a microstimulator or microsensor, having a dipole antenna that is formed by ceramic processes on the inner or outer surface of the ceramic case of the microdevice. The antenna receives data transmitted from an external device, and transmits data to an external device. A dipole antenna may be formed from two radiating elements separated by an insulating material. A tuning circuit comprising capacitors and/or inductors is used to obtain resonance in the dipole antenna. In a preferred embodiment, the antenna is formed of a biocompatible material by applying a metal-containing paste to the ceramic case of the microdevice and thermally processing it.

Claims

1. A dipole antenna formed on an implantable microdevice, said implantable microdevice having a case, said case being a hollow cylinder having an inner and an outer surface and adapted for housing communications circuitry, said dipole antenna comprising:

at least two radiating elements, wherein said radiating elements are electrically conducting and are formed on said outer surface; and

wherein said dipole antenna is electrically coupled to said communications circuitry to create a telemetry system for said implantable microdevice.

2. The dipole antenna of claim 1, wherein said case is comprised of a ceramic from the group consisting of alumina, glass, titania, zirconia, stabilized-zirconia, partially-stabilized zirconia, tetragonal zirconia, magnesia-stabilized zirconia, ceria-stabilized zirconia, calcia-stabilized zirconia, and yttria-stabilized zirconia.

3. The dipole antenna of claim 1, further comprising a tuning element that is electrically coupled to said radiating element, wherein said tuning element and said radiating element combine to form a resonant circuit.

4. The dipole antenna of claim 1, wherein said case is comprised of zirconia.

5. The dipole antenna of claim 1, wherein said radiating element is comprised of silver, platinum, palladium, or gold and no glass.

6. The dipole antenna of claim 1, wherein said radiating element is formed by brushing.

7. The dipole antenna of claim 1, wherein said implantable microdevice is a microstimulator.

8. The dipole antenna of claim 1, wherein said implantable microdevice is a microsensor.

9. The dipole antenna of claim 1, wherein said telemetry system receives a control signal from an external device.

10. The dipole antenna of claim 1, wherein said telemetry system transmits a signal to an external device.

11. The dipole antenna of claim 1, wherein said telemetry system has an operating frequency in the range of 402 to 405 MHz.

12. A dipole antenna formed on the outer surface of a case, comprising:

a tuning element that is electrically coupled to a radiating element, wherein said tuning element and said radiating element combine to form a resonant circuit;

at least two radiating elements, wherein said radiating elements are electrically conducting and are formed on the outer surface of the case; and

wherein said dipole antenna forms a loop antenna when immersed in electrically conductive living tissue.

13. A method of forming a dipole antenna on an implantable microdevice, said implantable microdevice having a ceramic case, said ceramic case being a hollow cylinder having an inner and an outer surface and adapted for housing communications circuitry, said method comprising the steps of:

selecting at least one radiating element design;

selecting a thick film layer of metal for said radiating element design;

applying said thick film layer of metal containing paste at about 20°

C. to said case in said radiating element design;

drying said thick film layer at 90°

to 130°

C.; and

firing said thick film layer at 900°

to 1200°

C. for 10 to 30 minutes.

14. The method of claim 13, wherein said selecting at least one radiating element design is selecting a straight line dipole antenna.

15. The method of claim 13, wherein said radiating element design is a spiral dipole antenna.

16. The method of claim 13, wherein said step of selecting said thick film layer of metal is selecting an electrically conducting platinum metal.

17. The method of claim 13, wherein said step of selecting said thick film layer is selecting an electrically conducting metal selected from the group of biocompatible metals.

18. The method of claim 13, wherein said step of applying said thick film layer of metal containing paste is applying to said outer surface of said case by brushing.

19. The method of claim 13, wherein said step of applying said thick film layer of metal containing paste is applying to said outer surface of said case by silk screening.

20. The method of claim 13, wherein said thick film layer of metal containing paste is applied to said outer surface of said case.

21. The method of claim 13, wherein said thick film layer of metal containing paste is applied to said inner surface of said case.

22. The method of claim 13, wherein said thick film layer is fired in a vacuum atmosphere.

23. The method of claim 13, wherein said selecting said thick film layer is an electrically conducting metal selected from the group of platinum, gold, silver, or mixtures thereof.