DETECTION OF LIFE-THREATENING CARDIAC-ARRHYTHMIAS USING THE WAVELET TRANSFORMATION

Time-frequency wavelet theory is used for the detection of life threat ening electrocardiography (ECG) arrhythmias. This is achieved through the use of the raised cosine wavelet transform (RCWT). The RCWT is fou nd to be useful in differentiating between ventricular fibrillation, v entricular tachycardia and atrial fibrillation. Ventricular fibrillati on is characterised by continuous bands in the range of 2-10Hz; ventri cular tachycardia is characterised by two distinct bands: the first ba nd in the range of 2-5Hz and the second in the range of 6-8Hz; and atr ial fibrillation is determined by a low frequency band in the range of 0-5 Hz. A classification algorithm is developed to classify ECG recor ds on the basis of the computation of three parameters defined in the time-frequency plane of the wavelet transform. Furthermore, the advant age of localising and separating ECG signals from high as well as inte rmediate frequencies is demonstrated. The above capabilities of the wa velet technique are supported by results obtained from ECG signals obt ained from normal and abnormal subjects.