Battery test circuit for a heart pacemaker

• US 4,686,990 A
• Filed: 09/17/1986
• Issued: 08/18/1987
• Est. Priority Date: 10/02/1985
• Status: Expired due to Term

• Current Assignee: Pacesetter AB
• Original Assignee: Siemens AG
• Inventors: Moberg, Lennart
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Keegan, Timothy
• Application Number:
  US06/908,213
• Time in Patent Office: 335 Days
• Field of Search: 128/419 PT, 128/419 PS, 128/419 PG, 128/697
• US Class Current: 607/29
• CPC Class Codes: A61N 1/3708 for power depletion

Abstract

A battery test circuit for a heart pacemaker generates a signal which corresponds to the charge status of the pacemaker battery which is displayable in a manner which does not interfere with the normal pacing frequency of the pacemaker. A marking pulse is generated by the circuit at a chronological position between successive stimulation pulses which is dependent upon the charge status of the battery at the time the marking pulse is generated.

Claims

1. A battery test circuit for a heart pacemaker which generates a plurality of successive stimulation pulses comprising:

means for generating an electrical signal corresponding to the charge status of the battery;

means for generating at least one marking pulse; and

means for mixing said marking pulse with said stimulation pulses with the marking pulse disposed at a chronological position with respect to at least one of said stimulation pulses which corresponds to said charge status.

2. A battery test circuit as claimed in claim 1, wherein said means for mixing mixes said marking pulse with said stimulation pulses with said marking pulse disposed at a selected distance between two successive stimulation pulses, said selected distance corresponding to said charge status.

3. A battery test circuit as claimed in claim 1, wherein said means for generating at least one marking pulse generates said marking pulse after each n^th stimulation pulse, wherein n is a whole number, and wherein said means for mixing mixes said marking pulse with said stimulation pulses with said marking pulse disposed at a chronological position with respect to said n^th stimulation pulse corresponding to a remaining fraction of said charge status, such that n plus said remaining fraction is equal to the remaining battery capacity.

4. A battery test circuit as claimed in claim 3, wherein n is measured in years.