Rate responsive pacemaker adapted to adjust lower rate limit according to monitored patient blood temperature
First Claim
1. A rate responsive pacemaker, having a controllable pulse generator for delivering pacing pulses, rate means for sensing at least one parameter containing information indicative of desired pacing rate and control means for controlling said pulse generator to deliver pacing pulses at a rate which is a function of said at least one parameter, said control means further comprising limit means for limiting rate pacing adjustment between a low rate limit (LRL) and an upper rate limit (URL), and having LRL means for adjusting said LRL, said LRL means havinga temperature sensor for determining patient blood temperature,measure means for determining from said patient blood temperature a measure of the daily low value of said blood temperature,means for determining a threshold temperature at a predetermined relation to said measure of daily low value,comparison means for continually comparing said blood temperature with said threshold, and up/down adjusting means for adjusting said LRL as a function of said comparison.
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Accused Products
Abstract
A rate responsive pacemaker is provided having the capability of automatically adjusting the lower rate limit (LRL) for sleep, or nighttime. The pacemaker has a temperature sensor for determining patient blood temperature, and processes patient blood temperature data to obtain an average daily low value of nighttime blood temperature. The pacemaker monitors blood temperature to determine a drop below a threshold which is coupled to the average daily low value, as well as when the rate of temperature change exceeds a predetermined limit, these two coincident conditions suggesting onset of nighttime and/or sleep. Lower rate limit is decremented, preferably by a predetermined amount at onset of nighttime, and is automatically incremented when patient blood temperature and/or time of day indicate the end of nighttime.
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Citations
15 Claims
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1. A rate responsive pacemaker, having a controllable pulse generator for delivering pacing pulses, rate means for sensing at least one parameter containing information indicative of desired pacing rate and control means for controlling said pulse generator to deliver pacing pulses at a rate which is a function of said at least one parameter, said control means further comprising limit means for limiting rate pacing adjustment between a low rate limit (LRL) and an upper rate limit (URL), and having LRL means for adjusting said LRL, said LRL means having
a temperature sensor for determining patient blood temperature, measure means for determining from said patient blood temperature a measure of the daily low value of said blood temperature, means for determining a threshold temperature at a predetermined relation to said measure of daily low value, comparison means for continually comparing said blood temperature with said threshold, and up/down adjusting means for adjusting said LRL as a function of said comparison.
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10. A rate responsive pacemaker system, having a controllable pulse generator for producing and delivering pace pulses, rate means for sensing at least one parameter containing information indicative of desired pacing rate and control means for controlling the rate of delivery of pace pulses as a function of said at least one parameter, said control means further comprising limit means for limiting rate pacing adjustment to rates above a low rate limit (LRL), and having LRL means for adjusting said LRL, said LRL means further comprising:
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a temperature sensor for determining patient blood temperature, threshold means for setting a low blood temperature threshold, said threshold means comprises low temperature means for determining patient daily average low blood temperature; temperature rate means for determining a measure of the rate of drop of patient blood temperature, determining means for determining the occurrence when patient blood temperature has fallen below said temperature threshold and said rate of drop has exceeded a predetermined rate, and initiating means for initiating a drop of LRL to a lower LRL when a said occurrence is determined. - View Dependent Claims (11, 12, 13, 14, 15)
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Specification