Method and system for detection of cardiac arrhythmia
First Claim
1. A method for detecting cardiac arrhythmia comprising:
- detecting RR intervals of a patient, wherein each RR interval is an interval between two heart beats;
constructing standard histograms of Δ
RRs collected during cardiac arrhythmia of a plurality of subjects, wherein each Δ
RR is a difference between two successive RR intervals;
constructing test histograms of Δ
RRs of the patient from the detected RR intervals of said patient, wherein the standard and test histograms are probability density histograms;
calculating a mean value of a given number of successive RR intervals of the patient;
choosing one of the standard probability density histograms in relation to said mean value, wherein choosing one of the standard probability density histograms comprises selecting the standard histogram corresponding to the range of RR intervals in which said mean value is located; and
comparing said standard and test histograms to detect whether said patient suffers from cardiac arrhthymia.
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Abstract
There are many different serious cardiac arrhythmias. The present invention uses measurements of RR intervals (interbeat intervals) to detect, in particular but not exclusively, atrial fibrillation of a patient. Atrial fibrilation is a serious ailment in which the heartbeat is generally rapid and irregular. Probability density histograms of ΔRRs (difference between two successive RR intervals) collected during atrial fibrillation of a plurality of subjects are used as a template for the detection of atrial fibrillation. In one implementation, there are 16 standard probability density ΔRRs histograms every 50 ms of mean RR interval of a certain number of beats, where the mean RR interval ranges from 350 ms to 1149 ms. Similarity between the standard probability density histograms and a test density probability histogram of ΔRRs of a patient is estimated by the Kolmogorov-Smirnov test. If the test density histogram is not significantly different from the standard density histogram, atrial fibrillation is detected.
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Citations
16 Claims
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1. A method for detecting cardiac arrhythmia comprising:
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detecting RR intervals of a patient, wherein each RR interval is an interval between two heart beats; constructing standard histograms of Δ
RRs collected during cardiac arrhythmia of a plurality of subjects, wherein each Δ
RR is a difference between two successive RR intervals;constructing test histograms of Δ
RRs of the patient from the detected RR intervals of said patient, wherein the standard and test histograms are probability density histograms;calculating a mean value of a given number of successive RR intervals of the patient; choosing one of the standard probability density histograms in relation to said mean value, wherein choosing one of the standard probability density histograms comprises selecting the standard histogram corresponding to the range of RR intervals in which said mean value is located; and comparing said standard and test histograms to detect whether said patient suffers from cardiac arrhthymia. - View Dependent Claims (2, 3, 4)
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5. A system for detecting cardiac arrhythmia comprising:
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a RR interval detecting monitor detecting RR intervals of a patient, wherein each RR interval is an interval between two heart beats; a standard Δ
RR histogram storage unit in which are stored standard histograms of Δ
RRs collected during cardiac arrhythmia of a plurality of subjects, wherein each Δ
RR is a difference between two successive RR intervals;a test Δ
RR histogram calculator supplied with the detected RR intervals from the monitor and constructing test histograms of said Δ
RRs of said patient, wherein the standard and test histograms are probability density histograms;a calculator of a mean value of a given number of successive RR intervals of the patient; a selector of one of the standard probability density histograms in relation to said mean value, wherein the selector of one of the standard probability density histograms comprises means for selecting the standard histogram corresponding to the range of RR intervals in which said mean value is located; and a standard and test Δ
RR histograms comparator supplied with said standard and test histograms, said comparator comprising a detector of cardiac arrhythmia of the patient responsive to the comparison of said standard and test histograms. - View Dependent Claims (6, 7, 8)
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9. An apparatus, comprising:
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means for detecting RR intervals of a patient, wherein each RR interval is an interval between two heart beats; means for constructing standard histograms of Δ
RRs collected during cardiac arrhythmia of a plurality of subjects, wherein each Δ
RR is a difference between two successive RR intervals;means for constructing test histograms of Δ
RRs of the patient from the detected RR intervals of said patient, wherein the standard and test histograms are probability density histograms;means for calculating a mean value of a given number of successive RR intervals of the patient and for choosing one of the standard probability density histograms in relation to said mean value, wherein the means for choosing one of the standard probability density histograms comprises means for selecting the standard histogram corresponding to the range of RR intervals in which said mean value is located; and means for comparing said standard and test histograms to detect whether said patient suffers from cardiac arrhthymia. - View Dependent Claims (10, 11, 12)
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13. A computer readable medium encoded with executable instructions for performing a method, comprising:
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instructions for detecting RR intervals of a patient, wherein each RR interval is an interval between two heart beats; instructions for constructing standard histograms of Δ
RRs collected during cardiac arrhythmia of a plurality of subjects, wherein each Δ
RR is a difference between two successive RR intervals;instructions for constructing test histograms of Δ
RRs of the patient from the detected RR intervals of said patient, wherein the standard and test histograms are probability density histograms;instructions for calculating a mean value of a given number of successive RR intervals of the patient and for choosing one of the standard probability density histograms in relation to said mean value, wherein the instructions for choosing one of the standard probability density histograms comprises instructions for selecting the standard histogram corresponding to the range of RR intervals in which said mean value is located; and instructions for comparing said standard and test histograms to detect whether said patient suffers from cardiac arrhthymia. - View Dependent Claims (14, 15, 16)
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Specification