Nonstationary ECG analysis using Wigner-Ville transform and wavelets

Nonstationary analysis of ECGs (especially the ST segment) was performed using the Wigner-Ville distribution (WVD) and wavelet transforms. The analysis was done on multiple leads of the same subject and on subjects with normal ECG, ischemia, necrosis and infarct. All data came from the CSE multilead database. It was found that the spectrotemporal maps were not considerably different from lead to lead and that substantial changes in spectrotemporal maps concerning the existence of nonstationarities exist among the above-mentioned pathological states. These changes were evident mainly in the QRS complex and the ST segment. Only in the infarcted subject did such changes persist over the whole P-QRS-T complex. The WVD was found superior from the wavelet transform in having better time- and frequency-domain resolution and superior computational performance