Envelopment filter and K-means for the detection of QRS waveforms in electrocardiogram.
The electrocardiogram (ECG) is a well-established technique for determining the electrical activity of the heart and studying its diseases. One of the most common pieces of information that can be read from the ECG is the heart rate (HR) through the detection of its most prominent feature: the QRS complex. This paper describes an offline version and a real-time implementation of a new algorithm to determine QRS localization in the ECG signal based on its envelopment and K-means clustering algorithm. The envelopment is used to obtain a signal with only QRS complexes, deleting P, T, and U waves and baseline wander. Two moving average filters are applied to smooth data. The K-means algorithm classifies data into QRS and non-QRS. The technique is validated using 22 h of ECG data from five Physionet databases. These databases were arbitrarily selected to analyze different morphologies of QRS complexes: three stored data with cardiac pathologies, and two had data with normal heartbeats. The algorithm has a low computational load, with no decision thresholds. Furthermore, it does not require any additional parameter. Sensitivity, positive prediction and accuracy from results are over 99.7%.
Department of Electronic Technology, University of Seville, Avd. Reina Mercedes s/n, 41012 Seville, Spain . Electronic address: manmermon@dte.us.es.
Manuel
M
Merino
Department of Electronic Technology, University of Seville, Avd. Reina Mercedes s/n, 41012 Seville, Spain.
Isabel María
IM
Gómez
Department of Electronic Technology, University of Seville, Avd. Reina Mercedes s/n, 41012 Seville, Spain.
Alberto J
AJ
Molina
D000465:Algorithms; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000503:physiopathology; D016208:Databases, Factual; D004562:Electrocardiography / Q000379:methods*; D005189:False Positive Reactions; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors
Biosignal processing; ECG signal; Envelopment; K-means clustering; QRS detection