Heart rate detection utilizing autoregressive analysis
First Claim
1. A detection system for determining the cardiac cyclic rate by detecting a predetermined component of the cardiac cycle, comprising:
- means for obtaining cardiac signals defining a plurality of cardiac cycles;
means for performing an autoregressive analysis filtering of said cardiac signals to remove color noise;
means for executing a low-pass filtering of the autoregressive filtered signals to remove white noise;
means for peak detecting the low-pass filtered signals to detect said predetermined component thereby determining said cyclic rate; and
means for displaying said cyclic rate in response to the detection of each predetermined component.
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Abstract
A system for determining the heart rate in response to an electrocardiogram (EKG) signal that has been filtered by performing an autoregressive analysis, low-pass filtered by performing a digital filtering function, and the rate determined by utilizing a digital peak detection technique. In a heart rate detection system, the EKG signal from an EKG instrument is first digitized and then the colored noise component is removed from the digitized EKG samples by performing a linear predictive coding filtering function on the EKG samples. After the colored noise has been filtered from the digitized EKG samples, a low-pass filtering function is performed to remove high-frequency white noise by utilizing a digital finite impulse response filter. Finally, the heart rate is determined from the previously filtered EKG samples by a peak detection technique that performs a recursive algorithm to determine both the amplitude of the remaining peaks in the EKG samples and the period between these peaks.
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Citations
14 Claims
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1. A detection system for determining the cardiac cyclic rate by detecting a predetermined component of the cardiac cycle, comprising:
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means for obtaining cardiac signals defining a plurality of cardiac cycles; means for performing an autoregressive analysis filtering of said cardiac signals to remove color noise; means for executing a low-pass filtering of the autoregressive filtered signals to remove white noise; means for peak detecting the low-pass filtered signals to detect said predetermined component thereby determining said cyclic rate; and means for displaying said cyclic rate in response to the detection of each predetermined component. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for determining heart beat rate by detecting the R-wave of the QRS complex of a patient'"'"'s electrocardiogram signal, comprising:
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means for obtaining said patient'"'"'s electrocardiogram signals; means for digitizing said electrocardiogram signals; means for dividing said digitized electrocardiogram signals into a plurality of channels each having a predefined number of electrocardiogram signals; means for computing reflection coefficients for each of said channels from said digitized electrocardiogram signals modeling noise contained within said electrocardiogram signals; means for computing the residual representing the difference between said model and said electrocardiogram signals from said residual thereby representing the linear filtered output signals of said model; means for storing a plurality of filtered coefficients defining a low-pass filter; means for computing output signals of said low-pass filter in response to said linear filtered signals and said stored filtered coefficients; means for locating the main R-peak of maximum amplitude within the low-pass filtered signals; means for locating peaks of lesser amplitude than that of said peak of maximum amplitude by not less than a minimum distance based on the highest expected heart rate from said peak of maximum amplitude and from each other within said low-pass filtered signals; means for measuring one-by-one the distances between adjacent peaks using as a reference the location of said peak of said maximum amplitude; means for testing for periodicity by comparing successive distance measurements for substantial equality and rejecting peaks which are not periodically related to the peak of maximum amplitude; and means for determining said heart rate from the periodicity.
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12. A monitoring method for determining the cardiac cycle rate by detecting a predetermined component of the cardiac cycle, comprising:
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reading the electrocardiogram signals of a patient for a plurality of cardiac cycles; performing an autoregressive analysis filtering of said electrocardiogram signals to remove color noise; removing white noise by low-pass filtering said autoregressive filtered signals; locating the main peak of maximum amplitude within the low-pass filtered signals; locating the main peak of maximum amplitude within the low-pass filtered signals; locating peaks of lesser amplitude than said peak of maximum amplitude by not less than a minimum distance based on the highest expected heart rate from said peak of maximum amplitude and from each other within said low-pass filtered signals; measuring the distance between adjacent peaks using as a reference the location of said peak of maximum amplitude; testing for periodicity by comparing successive distance measurements for substantial equality and rejecting peaks which are not periodically related to the peak of maximum amplitude; and determining said cardiac cycle rate from the periodicity. - View Dependent Claims (13)
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14. A method for measuring the heart rate of a patient in response to an electrocardiogram signal comprising the steps of:
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digitizing samples of said electrocardiogram signal; locating the peak of maximum amplitude in said digitized samples; locating peaks of lesser amplitude spaced a distance apart greater than the highest expected heart rate and having an amplitude greater than a predefined percentage of said peak of largest amplitude; measuring the distance between adjacent peaks; testing for periodicity by comparing successive distance measurements for substantial equality; and displaying the periodicity as an indication of said heart rate.
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Specification