Shielded pacemaker enclosure

• US 5,895,980 A
• Filed: 12/30/1996
• Issued: 04/20/1999
• Est. Priority Date: 12/30/1996
• Status: Expired due to Fees

• Current Assignee: Medical Pacing Concepts, Ltd.
• Original Assignee: Medical Pacing Concepts, Ltd.
• Inventors: Thompson, Thomas T.
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): SCHAETZLE, KENNEDY
• Application Number:
  US08/775,384
• Time in Patent Office: 841 Days
• Field of Search: 607/36, 607/67, 607/10, 607/63, 607/2
• US Class Current: 607/36
• CPC Class Codes: A61N 1/37512 Pacemakers

Abstract

A shielded pacemaker enclosure includes a first portion, and a second portion. Both portions have conductive surfaces disposed thereon. The portions are joined together to form a chamber therein. A connector is provided which extends through the enclosure to receive a lead. Additionally, filter and isolation circuitry is employed to provide further shielding.

Claims

1. A cardiac pacemaker, comprising:

an enclosure constructed from a non-conductive material the enclosure including first and second portions joined together to form a chamber therein;

a conductive surface defining an interior of the chamber, disposed adjacent the first and second portions;

a pacing connector including a first conductor and a second conductor, the pacing connector sealably extending from within the chamber, through the enclosure, the connector adapted to sealably receive a lead;

filter circuitry disposed within the chamber, including a first capacitor coupling the first conductor to the conductive surface, and a second capacitor coupling the second conductor to the conductive surface; and

a pacing circuit, having a reference potential connector connected thereto, disposed within the chamber and coupled to the pacing connector such that the reference potential connector is isolated from the conductive surface.

2. The pacemaker of claim 1 further comprising a first inductive member electrically interposed between the first conductor and the pacing circuit, and a second inductive member electrically interposed between the second conductor and the pacing circuit.

3. The pacemaker of claim 2 wherein the first and second inductive members comprise first and second ferrite beads, respectively.

4. The pacemaker of claim 2 further comprising:

a circuit board adapted to support the pacing circuit;

a circuit board reference potential connector coupled to the circuit board;

a first voltage regulator coupled to the first conductor of the pacing connector, and the circuit board reference potential connector; and

a second voltage regulator coupled to the second conductor of the pacing connector, and the circuit board reference potential connector.

5. The pacemaker of claim 4 further comprising a capacitor coupled to the first conductor of the pacing connector and the second conductor of the pacing connector.

6. The pacemaker of claim 1 wherein the conductive surface is substantially continuous.

7. The pacemaker of claim 1 wherein the conductive surface is constructed from nickel.

8. The pacemaker of claim 1 wherein the first capacitor of the filter circuitry, and second capacitor of the filter circuitry are attached electrically and mechanically to the conductive surface by means of a conductive adhesive.

9. The pacemaker of claim 1 wherein the first and second portions are constructed from plastic suitable for implantation into a human body.

10. A shielded pacemaker enclosure comprising:

a first portion including a first recess;

a first conductive surface disposed within the first recess;

a second portion including a second recess;

a second conductive surface disposed within the second recess;

a conductive adhesive layer electrically coupling the first and second conductive surfaces; and

a connector including a first conductor and a second conductor, the connector extending through said first and second portions.

11. The enclosure of claim 10 further comprising:

a first capacitor coupled to the first conductor, and one of the first conductive surface and second conductive surface; and

a second capacitor coupled to the second conductor and one of the first conductive surface and second conductive surface.

12. The enclosure of claim 10 further comprising:

a circuit board having a ground, and adapted to mount pacing circuitry;

a first voltage regulator including a first pair of Zener diodes arranged in back-to-back fashion, coupling the first conductor to the circuit board ground; and

a second voltage regulator including a second pair of Zener diodes arranged in back-to-back fashion, coupling the second conductor to the circuit board ground.

13. The enclosure of claim 10 wherein the first conductive surface is substantially continuous, and the second conductive surface is substantially continuous.

14. The enclosure of claim 10 wherein the first conductive surface and the second conductive surface are constructed from nickel.

15. The enclosure of claim 10 wherein the first portion and the second portion are constructed from plastic.

16. The enclosure of claim 15 wherein the first portion and the second portion are constructed from acrylonitrile butadiene styrene (ABS).

17. An external pacemaker comprising:

an enclosure including a first external part defining a first recess with a first conductive surface disposed therein, and a second external part with a second conductive surface disposed on a portion thereof, and a conductive layer joining the first and second conductive surfaces such that a chamber is formed therein, and the conductive surfaces are electrically coupled;

a pacing connector including a first conductor and a second conductor, the pacing connector extending from within the chamber through the enclosure, and adapted to receive a lead;

a pacing circuit disposed within the chamber and coupled to the pacing connector; and

a power source providing power to the pacing circuitry.

18. The pacemaker of claim 17 further comprising:

a first capacitor coupled to the first conductor, and one of the first conductive surface and second conductive surface; and

a second capacitor coupled to the second conductor and one of the first conductive surface and second conductive surface.

19. The pacemaker of claim 17 wherein the first conductive surface is substantially continuous, and the second conductive surface is substantially continuous.

20. The pacemaker of claim 17 wherein the first and second conductive surfaces are constructed from nickel.

21. The pacemaker of claim 17 wherein the first and second external parts are constructed from plastic.