ELECTRICALLY SHIELDED, GAS-PERMEABLE IMPLANTABLE ELECTRO-MEDICAL APPARATUS

• US 3,718,142 A
• Filed: 04/23/1971
• Issued: 02/27/1973
• Est. Priority Date: 04/23/1971
• Status: Expired due to Term

• Current Assignee: Pieter M.J. Mulier
• Original Assignee: Pieter M.J. Mulier
• Inventors: Mulier, Pieter M. J.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/136,890
• Time in Patent Office: 676 Days
• Field of Search: 128/419C,419E,419P,419R,421,422
• US Class Current: 607/36
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings

Abstract

A thin film of metal, deposited on an implantable cardiac stimulator, acting as a shield to prevent interference with the electronic circuitry of the stimulator, the interference produced by any outside apparatus which might induce RF interference on electrodes from the stimulator to the heart, or through the living tissue to the stimulator body itself. Also, before implantation, because of a variety of very well-known reasons, a static charge that may have been built up on the stimulator is avoided because of the deposited shielding.

Claims

1. In an implantable stimulator of the type having electronic circuitry and gas generating battery means all encased in a material having a substantially higher permeability to battery gas than body fluids, and at least one electrode, the improvement which comprises:

film means covering said encasing material for allowing the escape of battery gases from said encasing material while preventing the passage of substantial amounts of body fluids therethrough, said film means comprising a thin film of metal capable of shielding the electronic circuitry from extraneous interference signals.

2. The implantable stimulator of claim 1 wherein said battery gas escape is accomplished through a rupture in the film means.

3. The implantable stimulator of claim 2 further comprising an electronic filter means connected between each electrode and the film means for shunting interference signals impressed on the electrode to the film means.

4. The implantable stimulator of claim 3 wherein the filter means comprises a capacitor providing a direct AC connection between the electrodes and the film means.

5. The stimulator of claim 4 wherein the thin film of metal is deposited by sputtering.

6. The stimulator of claim 4 wherein the thin film is deposited by evaporation deposition.

7. The implantable stimulator of claim 1 wherein said film means has a plurality of pinholes therein, said battery gas escape being accomplished through the pinholes.

8. The implantable stimulator of claim 7 further comprising an electronic filter means connected between each electrode and the film means for shunting interference signals impressed on the electrode from the film means.

9. The implantable stimulator of claim 8 wherein the filter means comprises a capacitor providing a direct AC connection between the electrodes and the film means.

10. The stimulator of claim 9, wherein the thin film is deposited by sputtering.

11. The stimulator of claim 9, wherein the thin film is deposited by evaporation deposition.