Arrhythmia detection in human electrocardiogram
G. V. S. Chiranjivi, Vamsi Krishna Madasu, Madasu Hanmandlu, Brian C. Lovell · 2005
The Electrocardiogram (ECG), by appropriate mathematical exploration, can be used to detect a majority of heart ailments. As a first step of detection of the disease, the ECG of a medically sound person must be distinguished from that of a diseased person. In this paper, we discuss a method to distinguish a normal sinus rhythm ECG from an arrhythmic ECG. The method involves the study of the shape of beats. Though there are slight alterations, the shape of the beats in an ECG sample largely remains the same. The frequencies that determine the shape of each beat vary; however, only by a small amount with the occurrence of every new beat. Substantial phase coupling among some frequencies present in the beats of an ECG sample might be the cause for such a similarity in the shape of the beats. Though there may be other frequencies that contribute to the shape of the beat, the contribution of the phase-coupled frequencies is significant. Such phase coupled frequencies of an ECG signal are traced by using the third order spectrum namely the Bispectrum. The bispectral frequencies determine the elemental shape of every beat present in the sample. Having found the bispectral frequencies present in the sample, the Fourier series of the replicated individual beat is studied. By appropriate comparison of the two, the frequency components present in the beat, which determine the shape of beat can be known. The properties of such frequencies can effectively characterize an ECG into rhythmic or arrhythmic.