Gas-absorbing pacer and method of fabrication

• US 4,127,134 A
• Filed: 04/11/1977
• Issued: 11/28/1978
• Est. Priority Date: 04/11/1977
• Status: Expired due to Term

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Inventors: Ushakoff, Alexis E.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/786,112
• Time in Patent Office: 596 Days
• Field of Search: 128/419 P, 128/419 PS, 252/181.1, 316/25, 429/57, 429/59
• US Class Current: 607/9
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: H01M 10/52 Removing gases inside the secondary cell, e.g. by absorption vent plugs or other mechanical arrangements for facilitating escape of gases H01M50/30
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The cardiac pacer disclosed herein is of the type in which pulse-generating circuitry is energized by an electro-chemical cell of a type which gives off hydrogen during depletion of the cell, e.g. a mercury battery. A hermetically sealed case is provided for enclosing both the circuitry and the electro-chemical cell to protect them from body fluids, the case having at least one feed-through terminal for coupling pulses generated by the circuitry to a lead adapted for contacting a patient'"'"'s heart. A getter is disposed within the case consisting essentially of a solid mass of palladium metal having a thin layer of palladium oxide formed on the outer surface thereof. A preferred method of forming the palladium oxide is by anodizing the mass of palladium metal in a sulphuric acid bath.

Claims

1. An implantable cardiac pacer comprising:

circuitry which, when energized, operates to controllably generate electrical pulses suitable for cardiac stimulation;

means for energizing said circuitry, including at least one electro-chemical cell of a type which gives off hydrogen during depletion of the cell;

a case enclosing said circuitry and said cell for protecting them from body fluids, said case being hermetically sealed and having at least one feed-through terminal for coupling pulses generated by said circuitry to a lead adapted for contacting a patient'"'"'s heart;

also within said case, a getter comprising a solid mass of palladium metal for absorbing hydrogen given off by the cell, said solid mass having a thin layer of palladium oxide formed on the outer surface thereof for greatly increasing the rate of absorption of hydrogen into the mass of palladium metal.

2. A pacer as set forth in claim 1 including a pair of cylindrical getters each of which is about 0.50 inches long and about 0.19 inches in diameter.

3. A pacer as set forth in claim 1 wherein said layer is formed on said mass of palladium metal by anodizing in sulphuric acid.

4. A pacer as set forth in claim 1 wherein said energizing means includes a mercury battery comprising a plurality of cells.

5. A method of fabricating a cardiac pacer which comprises:

providing a suitably shaped solid mass of palladium metal;

anodizing said metallic mass to form on the outer surface thereof a thin layer of palladium oxide;

hermetically sealing within a case;

the anodized mass of palladium metal;

circuitry which, when energized, operates to generate electrical pulses suitable for cardiac stimulation; and

means for energizing said circuitry, including at least one electro-chemical cell of a type which gives off hydrogen during depletion of the cell;

said case having a feed-through terminal for coupling pulses generated by said circuitry to a lead adapted for contacting a patient'"'"'s heart.

6. The method as set forth in claim 5 wherein the anodization of said palladium metal is performed in diluted sulphuric acid.

7. The method as set forth in claim 5 wherein said energizing means includes a plurality of mercury cells sealed in said case.