CARDIAC PACER WITH REDUNDANT POWER SUPPLY

• US 3,620,220 A
• Filed: 10/01/1969
• Issued: 11/16/1971
• Est. Priority Date: 10/01/1969
• Status: Expired due to Term

• Current Assignee: Telectronics Incorporated
• Original Assignee: William P. Murphy Jr
• Inventors: William, P. Murphy Jr.
• Primary Examiner(s): William E. Kamm
• Application Number:
  US04/862,657
• Time in Patent Office: 776 Days
• Field of Search: 128/419P 307/48,64-66,71,80,85,86,87 320/1
• US Class Current: 607/34
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: H02H 7/18 for batteries; for accumulators

Abstract

The cardiac pacer disclosed herein employs a redundant power supply in which a pair of batteries are connected to pulsegenerating circuitry through the collector-emitter circuits of respective transistors. A forward-biasing current is applied to the transistor base terminals, which are connected together, so that the batteries energize the pulse-generating circuitry jointly when both are in satisfactory condition and, upon the occurrence of a failure in one of the batteries, the failing battery is effectively isolated from the pacer circuitry.

Claims

1. An implantable cardiac pacer, said pacer comprising:

a pulse-generating circuit operable when energized to provide cardiac-stimulating electrical pulses to electrodes attached to a patient'"'"''"'"'s heart;

first and second batteries;

first and second transistors;

circuit means for connecting said pulse-generating circuit across said first battery through the collector-emitter circuit of said first transistor and across said second battery through the collector-emitter circuit of said second transistor, the collectors of saId transistors being commonly connected to one side of said pulse-generating circuit; and

means for applying a forward-biasing current to the base terminals of said transistors in common whereby said pulsegenerating circuit is jointly energized by said batteries as long as both batteries are in satisfactory condition and, upon a reduction in voltage in one of said batteries, the load is transferred to the other battery.

2. A pacer as set forth in claim 1 wherein each of said batteries comprises a pair of mercury cells.

3. A pacer as set forth in claim 1 wherein said batteries each provide current at a potential of about 2.8 volts.

4. A pacer as set forth in claim 1 wherein said forward biasing current is related to the current drain of said pulse-generating circuit by a factor generally equal to the minimum gain of said transistors.

5. An implantable cardiac pacer, said pacer comprising:

a pulse-generating circuit;

electrode means for coupling pulses generated by said circuit to the heart of a patient;

first and second transistors, the collectors of said transistors being commonly connected to one side of said pulse-generating circuit;

first and second batteries, one terminal of each battery being connected to the emitter of a respective one of said transistors, the other terminals of said batteries being connected in common to the other side of said pulse-generating circuit; and

a resistor connecting the base terminals of said transistors in common to the aforesaid other terminals of said batteries thereby to forward bias at least one of said transistors whereby said pulse-generating circuit is jointly energized by said batteries as long as both provide substantially equal voltages and, upon a reduction in voltage in one of said batteries, the load is transferred to the other battery.