Medical device with morphology discrimination
First Claim
1. A medical device for monitoring waveform complexes of intracardiac electrograms, which comprises:
- electrode means adapted to be coupled to a patient'"'"'s heart;
sensing means having an input coupled to said electrode means for sensing analog intracardiac electrograms;
analog to digital converter means for converting the analog intracardiac electrogram to digital form;
means for examining the intracardiac electrogram, said examining means comprising means for determining, with respect to a waveform peak of said digitized intracardiac electrogram, its amplitude, width and polarity, to provide identification criteria;
means for storing said identification criteria;
means for averaging a plurality of waveform complexes to provide a standard complex and means for periodically operating said averaging means when a predetermined number of waveform complexes have occurred.
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Accused Products
Abstract
A medical device is provided for monitoring waveform complexes of intracardiac electrograms. The intracardiac electrogram is identified by determining, with respect to a waveform peak of the intracardiac electrogram, its amplitude, width and polarity. The identification criteria are averaged and stored to provide a standard complex. Subsequent complexes are compared to the stored standard complex. Such comparison includes comparing peaks of subsequent complexes with the peaks of a stored standard complex, aligning subsequent complexes with a stored standard complex, and providing a score associated with the comparisons and alignment.
172 Citations
23 Claims
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1. A medical device for monitoring waveform complexes of intracardiac electrograms, which comprises:
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electrode means adapted to be coupled to a patient'"'"'s heart; sensing means having an input coupled to said electrode means for sensing analog intracardiac electrograms; analog to digital converter means for converting the analog intracardiac electrogram to digital form; means for examining the intracardiac electrogram, said examining means comprising means for determining, with respect to a waveform peak of said digitized intracardiac electrogram, its amplitude, width and polarity, to provide identification criteria; means for storing said identification criteria; means for averaging a plurality of waveform complexes to provide a standard complex and means for periodically operating said averaging means when a predetermined number of waveform complexes have occurred. - View Dependent Claims (7, 8)
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2. A medical device for monitoring waveform complexes of intracardiac electrograms, which comprises:
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electrode means adapted to be coupled to a patient'"'"'s heart; sensing means having an input coupled to said electrode means for sensing analog intracardiac electrograms; analog to digital converter means for converting the analog intracardiac electrogram to digital form; means for examining the intracardiac electrogram, said examining means comprising means for determining, with respect to a wave from peak of said digitized intracardiac electrogram, its amplitude, width and polarity, to provide identification criteria; means for storing said identification criteria; and means for concluding if the examined peak is within the same waveform complex as the previous peak. - View Dependent Claims (3, 4, 5, 6)
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9. A self-contained implantable medical device for monitoring waveform complexes of intracardiac electrograms, which comprises:
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electrode means adapted to be coupled to a patient'"'"'s heart; sensing means having an input coupled to said electrode means for sensing analog intracardiac electrograms; analog to digital converter means for converting the analog intracardiac electrogram to digital form; means for examining the intracardiac electrogram, said examining means comprising means for determining, with respect to a waveform peak of said digitized intracardiac electrogram, its amplitude, width, and polarity, to provide identification criteria; means for storing said identification criteria to provide a standard waveform complex; and means for comparing subsequent complexes with said stored standard complex, said comparison means including means for providing a score associated with the comparison as a weighted function of whether the compared peaks exceed a predetermined upper threshold.
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10. A method for monitoring waveform complexes of intracardiac electrograms, which comprises the steps of:
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providing electrode means adapted for coupling to a patient'"'"'s heart; sensing analog intracardiac electrograms from said electrode means; converting the analog intracardiac electrograms to a digital format; examining the intracardiac electrogram, said examining step comprising the step of determining, with respect to a waveform peak of said digitized intracardiac electrogram, its amplitude, width and polarity, to provide identification criteria; storing said identification criteria; and periodically averaging a plurality of waveform complexes to provide a standard complex when a predetermined number of waveform complexes have occurred. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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11. A method of monitoring waveform complexes of intracardiac electrograms, which comprises the steps of:
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providing electrode means adapted for coupling to a patient'"'"'s heart; sensing analog intracardiac electrograms from said electrode means; converting the analog intracardiac electrograms to a digital format; examining the intracardiac electrogram, said examining step comprising the step of determining, with respect to a waveform peak of said digitized intracardiac electrogram, its amplitude, width and polarity, to provide identification criteria; storing said identification criteria; and concluding if the examined peak is within the same waveform complex as the previous peak. - View Dependent Claims (12, 13, 14, 15)
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22. A method of comparing a digitized subject electrogram complex with a digitized standard electrogram complex to generate a score which is a measure of their similarity or dissimilarity, each complex having a plurality of peaks with each peak being characterized by an amplitude, width and polarity, said method comprising the steps of:
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(a) determining, for each complex, the amplitude, width and polarity of each peak; (b) aligning said subject complex with said standard complex; (c) initializing said score; (d) comparing the amplitude, width and polarity of peaks within said subject complex with corresponding peaks within said standard complex; and (e) increasing or decreasing said score in a manner weighted as a function of whether the amplitude of either of the compared peaks exceeds a predetermined threshold.
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23. A method of comparing a digitized subject electrogram complex with a digitized standard electrogram complex to generate a score which is a measure of their similarity or dissimilarity, each complex having a plurality of peaks with each peak being characterized by an amplitude, width and polarity, said method comprising the steps of:
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(a) determining, for each complex, the amplitude, width and polarity of each peak having an amplitude greater than a predetermined lower threshold; (b) aligning said subject complex with said standard complex; (c) defining those peaks having an amplitude above a predetermined upper threshold as Upeaks; (d) determining for each peak in said subject complex if there is a corresponding peak in said standard complex and subtracting from said score a relatively greater amount if there is no corresponding peak and said subject peak is an Upeak and a relatively lesser amount if there is no corresponding peak and said subject peak is not an Upeak; (e) determining for each peak in said standard complex if there is a corresponding peak in said subject complex and subtracting from said score a relatively greater amount if there is no corresponding peak and said standard peak is an Upeak and a relatively lesser amount if there is no corresponding peak and said standard peak is not an Upeak; (f) for each remaining pair of corresponding peaks, determining if said subject complex peak has the same polarity as said standard complex peak and if said peaks have a different polarity subtracting a relatively greater amount from said score if either peak is an Upeak and a relatively lesser amount if neither peak is an Upeak; and (g) for each remaining pair of corresponding peaks having the same polarity, determining if both the amplitude and width of each subject complex peak is within a predetermined error of the amplitude and width of said corresponding standard complex peak and if the amplitude and width are within said predetermined error, adding a relatively greater amount to said score if said standard complex peak is an Upeak and if not, adding a relatively lesser amount to said score; and
if either of the amplitude or width is not within said predetermined error, subtracting a relatively greater amount if either of said peaks is an Upeak and a relatively lesser amount if neither of said peaks is an Upeak.
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Specification