QRS complex identification in electrocardiogram signals
First Claim
1. A method for identifying a QRS complex in an Electrocardiogram (ECG) signal, the method comprising:
- receiving the ECG signal captured by an ECG recorder, wherein the ECG signal is indicative of an electrical activity of heart of an individual;
filtering the ECG signal by passing the ECG signal through at least one of a first low-pass filter and a high-pass filter to obtain a filtered ECG signal;
squaring the filtered ECG signal to obtain a squared filtered ECG signal;
generating an envelope ECG signal by capturing peaks of the squared filtered ECG signal;
determining a moving average ECG signal based on a moving average of sample points associated with the envelope ECG signal, wherein a sample point is indicative of an amplitude of the envelope ECG signal at a time instance; and
filtering the moving average ECG signal to obtain a processed ECG signal, by passing the moving average ECG signal through a second low-pass filter;
identifying a search region in the processed ECG signal, wherein the search region is indicative of a time span between two consecutive peaks of the processed ECG signal;
identifying a maximum amplitude peak in a time interval of the filtered ECG signal that corresponds to the time span of the search region of the processed ECG signal, wherein the maximum amplitude peak is an R peak of an R wave of the QRS complex; and
identifying a Q peak of a Q wave, and an S peak of an S wave, of the QRS complex based on the R peak of the R wave.
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Abstract
The present subject matter relates to processing of Electrocardiogram (ECG) signals, and in particular, relates to identifying a QRS complex in an ECG signal. The method includes receiving, and filtering the ECG signal by passing through at least one of a first low-pass filter and a high-pass filter to obtain a filtered ECG signal. The filtered ECG signal is processed based on a moving average technique. Further, a search region is identified in the processed ECG signal, and a maximum amplitude peak is identified in a time interval of the filtered ECG signal that corresponds to a time span of the search region of the processed ECG signal. The maximum amplitude peak is an R peak of the QRS complex. Subsequently, a Q peak and an S peak of the QRS complex is identified based on the R peak.
16 Citations
17 Claims
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1. A method for identifying a QRS complex in an Electrocardiogram (ECG) signal, the method comprising:
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receiving the ECG signal captured by an ECG recorder, wherein the ECG signal is indicative of an electrical activity of heart of an individual; filtering the ECG signal by passing the ECG signal through at least one of a first low-pass filter and a high-pass filter to obtain a filtered ECG signal; squaring the filtered ECG signal to obtain a squared filtered ECG signal; generating an envelope ECG signal by capturing peaks of the squared filtered ECG signal; determining a moving average ECG signal based on a moving average of sample points associated with the envelope ECG signal, wherein a sample point is indicative of an amplitude of the envelope ECG signal at a time instance; and filtering the moving average ECG signal to obtain a processed ECG signal, by passing the moving average ECG signal through a second low-pass filter; identifying a search region in the processed ECG signal, wherein the search region is indicative of a time span between two consecutive peaks of the processed ECG signal; identifying a maximum amplitude peak in a time interval of the filtered ECG signal that corresponds to the time span of the search region of the processed ECG signal, wherein the maximum amplitude peak is an R peak of an R wave of the QRS complex; and identifying a Q peak of a Q wave, and an S peak of an S wave, of the QRS complex based on the R peak of the R wave. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A QRS identification system for identifying a QRS complex in an Electrocardiogram (ECG) signal, the QRS identification system comprising:
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a processing unit; a signal receiving block, coupled to the processing unit, to receive the ECG signal captured by an ECG recorder, wherein the ECG signal is indicative of an electrical activity of heart of an individual; and filter the ECG signal by passing the ECG signal through at least one of a first low-pass filter and a high-pass filter to obtain a filtered ECG signal; a signal processing block, coupled to the processing unit, to square the filtered ECG signal to obtain a squared filtered ECG signal; generate an envelope ECG signal by capturing peaks of the squared filtered ECG Signal; determine a moving average ECG signal based on a moving average of sample points associated with the envelope ECG signal, wherein a sample point is indicative of an amplitude of the envelope ECG signal at a time instance; and filter the moving average ECG signal to obtain a processed ECG signal, by passing the moving average ECG signal through a second low-pass filter; and a QRS identification block, coupled to the processing unit, to determine a search region in the processed ECG signal, wherein the search region is indicative of a time span between two consecutive peaks of the processed ECG signal; detect a maximum amplitude peak in a time interval of the filtered ECG signal that corresponds to the time span of the search region of the processed ECG signal, wherein the maximum amplitude peak is an R peak of an R wave of the QRS complex; and identify a Q peak of a Q wave and an S peak of an S wave of the QRS complex, based on the R peak of the R wave. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15)
determine a first peak point in a segment of the filtered ECG signal, within the first sub-search region, wherein the segment comprises a predefined number of consecutive sample points with slope greater than a predefined slope threshold, and wherein the first peak point is one of the predefined number of consecutive sample points in the segment; and determine a second peak point that corresponds to a peak of the filtered ECG signal in the first sub-search region, wherein the second peak point is determined as a zero crossing point of a slope signal, wherein the slope signal is obtained from three-point derivatives of filtered ECG signal in the first sub-search region; wherein the Q peak of the Q wave of the QRS complex is identified as one of the first peak point and the second peak point which is closer to the R peak of the R wave of the QRS complex.
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12. The QRS identification system as claimed in claim 11, wherein the QRS identification block is coupled to the processing unit to
determine a third peak point of the filtered ECG signal, based on a minimum value of the filtered ECG signal in the first sub-search region, when the first peak point and the second peak point are not determined, wherein the Q peak of the Q wave of the QRS complex is identified as the third peak point. -
13. The QRS identification system as claimed in claim 7, wherein the QRS identification block is coupled to the processing unit to
identify a second sub-search region of the filtered ECG signal, wherein the second sub-search region is a region comprising a predefined set of sample points of the filtered ECG signal after a time instance of the R peak; -
determine a first peak point in a segment of the filtered ECG signal, within the second sub-search region, wherein the segment comprises a predefined number of consecutive sample points with slope greater than a predefined slope threshold, and wherein the first peak point is one of the predefined number of consecutive sample points in the segment; determine a second peak point that corresponds to a peak of the filtered ECG signal in the second sub-search region, wherein the second peak point is determined as a zero crossing point of a slope signal, wherein the slope signal is obtained from three-point derivatives of filtered ECG signal in the first sub-search region; and wherein the S peak of the S wave of the QRS complex is identified as one of the first peak point and the second peak point which is closer to the R peak of the R wave of the QRS complex.
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14. The QRS identification system as claimed in claim 13, wherein the QRS identification block is coupled to the processing unit to
determining a third peak point of the filtered ECG signal, based on a minimum value of the filtered ECG signal in the second sub-search region, when the first peak point and the second peak point are not determined, wherein the S peak of the S wave of the QRS complex is identified as the third peak point. -
15. The QRS identification system as claimed in claim 7, wherein the first low-pass filter has a cut-off frequency within a range of 15 Hz-40 Hz, and wherein the high-pass filter has a cut-off frequency within a range of 0.5 Hz-5 Hz, and wherein the second low-pass filter has a cut-off frequency within a range of 8 Hz-16 Hz.
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16. A cardiovascular disease detection apparatus for detection of cardiovascular diseases using QRS complex in Electrocardiogram (ECG) signals, the cardiovascular disease detection apparatus comprising:
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a clock generator; an ECG recorder, coupled to the clock generator, to record an ECG signal, the ECG signal being indicative of an electrical activity of heart of an individual; and a QRS identification system, coupled to the clock generator, to receive the ECG signal captured by the ECG recorder; filter the ECG signal by passing the ECG signal through at least one of a first low-pass filter and a high-pass filter to obtain a filtered ECG signal; square the filtered ECG signal to obtain a squared filtered ECG signal; generate an envelope ECG signal by capturing peaks of the squared filtered ECG signal; determine a moving average ECG signal based on a moving average of sample points associated with the envelope ECG signal, wherein a sample point is indicative of an amplitude of the envelope ECG signal in a time-amplitude curve at a time instance; and filter the moving average ECG signal to obtain a processed ECG signal, by passing the moving average ECG signal through a second low-pass filter; identify a search region in the processed ECG signal, wherein the search region is indicative of a time span between two consecutive peaks of the processed ECG signal; identify a maximum amplitude peak in a time interval of the filtered ECG signal that corresponds to the time span of the search region of the processed ECG signal, wherein the maximum amplitude peak is an R peak of an R wave of the QRS complex; and identify a Q peak of a Q wave and an S peak of an S wave of the QRS complex, based on the R peak of the R wave; and a disease detector for detecting a cardiovascular disease based on the QRS complex of the ECG signal. - View Dependent Claims (17)
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Specification