Time-frequency analysis of non-stationary electrocardiogram signals using Hilbert-Huang Transform

Electrocardiogram (ECG) is a measure of an electrical activity of heart which is used to analyze the functioning of the heart of a person. This analysis helps the physician to diagnose the condition of the patient. As the ECG signals are non-stationary in nature, they cannot be analyzed with earlier techniques as they are limited. We therefore need robust methods like Hilbert-Huang Transform and Wavelet Transform to analyze such signals. In this paper I have employed Hilbert Huang Transform to analyze the ECG signal and plotted the time-frequency plot. HHT is a latest data analysis method proposed by Huang et al. which analyses non-linear and non-stationary signals by decomposing them into Intrinsic Mode Functions (IMF) followed by finding out their instantaneous frequencies of Intrinsic Mode Functions (IMF) with Hilbert Transform.