Automatic detection of P wave in ECG during ventricular extrasystoles

This work introduces a new method for P wave detection in ECG signals during ventricular extrasystoles. The authors of previous works which deal with detec-tion of P waves tested their algorithms mainly on physiological records (sinus rhythm) and they reached good results for these records. Testing of P wave de-tection algorithms using pathological records is usually not provided and if it is, the results are notably worse than in the case of physiological records. The auto-matic and reliable detection of atrial activity in pathological situations is still an unsolved problem. In this work, phasor transform in combination with classifica-tion algorithm is used for P wave detection. Phasor transform converts each ECG sample into a phasor which enhances changes in the ECG signal. The classifica-tion is based on extraction of morphological features which are derived from each QRS complex. The results of classification are used for demarcation of areas in which P waves are searched using phasor transform. The proposed algorithm was tested on signals no. 106, 119, 214 and 223 from MIT-BIH arrhythmia da-tabase, in which the ventricular extrasystoles are present. For validation whether the algorithm is functional also for signals with physiological rhythm, it was test-ed on the signals no. 100, 101, 103, 117, and 122. The accuracy of the P wave detection in signals with ventricular extrasystoles is Se = 98.94 % and PP = 98.30 % and in signals without pathology is Se = 98.47 % and PP = 99.99 %.