Time-frequency analysis of a noised ECG signals using empirical mode decomposition and Choi-Williams techniques

The electrocardiogram ECG is an important measurement to evaluate the safety of the cardiovascular system. The ECG analysis is usually faced with two major problems, the presence of the noise and the non-stationary multicomponent nature of the electrocardiogram ECG signal. These problems can influence in the analysis of such biomedical signal. This paper proposes a combination of two methods, the empirical mode decomposition EMD and the Choi-Williams time-frequency techniques, for analysing a noised ECG signal to diagnose cardiac arrhythmia. The work is divided into two steps; the first one consists in applying the EMD method to a noised abnormal ECG signal to filter the noise. The second one presents the analysis of the resulting signal by using the Choi-Williams time-frequency technique to extract different components, especially the QRS complexes, in order to detect the anomaly present in the signal. The obtained results illustrate the effectiveness of the combination of the EMD method and the Choi-Williams time-frequency technique in analysing the noised electrocardiogram signal.