Self-calibrating rate-adaptive pacemaker

• US 20040230240A1
• Filed: 05/06/2004
• Published: 11/18/2004
• Est. Priority Date: 09/08/2000
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Lang, Douglas J., Hopper, Donald, Sun, Weimin, Jones, Bruce R.
• Granted Patent: US 7,079,897 B2
• Time in Patent Office: Days
• US Class Current: 607/17
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters

Abstract

A system and method for automatically adjusting the operating parameters of a rate-adaptive cardiac pacemaker. In accordance with the method, maximum exertion levels attained by the patient are measured at periodic intervals and stored. The stored maximum exertion levels may then be used to update a long-term maximal exertion level, and the slope of the rate-response curve is adjusted to map the updated long-term maximal exertion level to a maximum allowable pacing rate. The stored maximum exertion levels may also be used to update a sensor target rate which is used to adjust the slope of the rate response curve.

Claims

1-18. -18. (Canceled)

19. A system for automatically adjusting the responsiveness of a rate-adaptive pacemaker operating in a patient, wherein measured exertion levels in the patient are mapped to a sensor indicated rate by a rate response curve, comprising:

means for collecting daily maximum exertion levels and daily maximum sensor indicated rates;

means for computing weekly averages of the daily maximum exertion levels and sensor indicated rates;

means for computing a sensor target rate as a function of the weekly average daily maximum exertion level and the patient'"'"'s maximum exercise capacity as defined by a long-term maximum exertion level; and

,

means for periodically adjusting the slope of the rate response curve in accordance with the difference between the weekly average maximum sensor indicated rate and the sensor target rate.

20. The system of claim 19 further comprising:

means for periodically updating the long-term maximal exertion level of the patient to equal a maximum among the collected daily maximum exertion levels during a specified time period; and

,

means for adjusting the slope of the rate response curve in order for the updated long-term maximal exertion level to be mapped to a specified maximum sensor indicated rate.

21. The system of claim 19 wherein the collected daily maximum exertion levels and sensor indicated rates are maximums among moving averages of the exertion levels and sensor indicated rates measured during a day.

22. The system of claim 19 further comprising means for adjusting the slope of the rate response curve by a specified step amount so as to increase or decrease the responsiveness of the pacemaker in accordance with whether the weekly average maximum sensor indicated rate is lesser or greater, respectively, than the sensor target rate.

23. The system of claim 22 wherein the rate response curve is a dual-slope curve with a slope that changes from a low rate response factor to a high rate response factor at a heart rate breakpoint that is computed as a percentage of the patient'"'"'s rate reserve and further wherein the rate response curve is adjusted by increasing or decreasing the low rate response factor.

24. The system of claim 23 wherein the high rate response factor is adjusted to map the patient'"'"'s long-term maximum exertion level to the maximum sensor indicated rate.