| US 7,580,749 B2 | ||
| Method for monitoring end of life for battery | ||
| Michael J. Lyden, Shoreview, Minn. (US) | ||
| Assigned to Cardiac Pacemakers, Inc., St. Paul, Minn. (US) | ||
| Filed on Jul. 18, 2007, as Appl. No. 11/779,779. | ||
| Application 11/779779 is a division of application No. 10/631995, filed on Jul. 31, 2003, granted, now 7,251,527. | ||
| Application 10/631995 is a division of application No. 10/093141, filed on Mar. 06, 2002, granted, now 6,654,640. | ||
| Application 09/670653 is a division of application No. 08/929629, filed on Sep. 15, 1997, granted, now 6,167,309. | ||
| Application 10/093141 is a continuation of application No. 09/670653, filed on Sep. 27, 2000, abandoned. | ||
| Prior Publication US 2007/0265672 A1, Nov. 15, 2007 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. A61N 1/37 (2006.01) | ||
| U.S. Cl. 607—29 [607/27; 607/9] | 25 Claims |
| 1. A system, including:
a battery power terminal for a battery;
sensing and pacing control circuitry electrically connected to the battery power terminal;
a pacing supply storage (PSS) capacitor electrically connected to the battery power terminal and to a discharge switch;
comparison circuitry, including:
a first comparator electrically connected to the battery power terminal and adapted for comparing a battery terminal voltage
(Vbatt) to a brownout voltage (Vstop), the first comparator having a first comparator output;
a second comparator electrically connected to the PSS capacitor and adapted for comparing a pacing supply storage voltage
(Vcs) to at least one reference voltage (Vx), the second comparator having a second comparator output, wherein the first comparator
output and the second comparator output are adapted to control current flow from the battery power terminal to the PSS capacitor;
and
charge time measurement (CTM) control circuitry electrically connected to the sensing and pacing control circuitry, the comparator
circuitry and the discharge switch, the charge time measurement control circuitry being adapted to:
access a predetermined set of charge time measurement set-up parameters and a predetermined elective replacement time (ERT)
charge time limit determined from a battery resistance ERT target that corresponds to a charge depletion target;
determine a rate of charge storage in the PSS capacitor using the predetermined set of charge time measurement set-up parameters;
compare the determined rate of charge storage in the PSS capacitor to the predetermined ERT charge time limit for the predetermined
set of charge time measurement set-up parameters; and
declare an ERT based on a number of comparisons between the determined rate of charge storage in the charge storage capacitor
and the ERT charge time limit.
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