QRS Complex and T Wave Detection using STFT

Objective: Precisely localize QRS complex and T wave of Electrocardiogram (ECG). Severe cardiovascular abnormalities like Ventricular Arrhythmias, Ventricular Hypertrophy, and Myocardial Infarction may occur due to the ventricular tissue dysfunctioning. The morphological changes in QRS and T wave of ECG represent the depolarization and repolarization disturbances and analysis of these segments alone may lead to identifying certain acute cardiac condition. Methodology: Presented algorithm comprises of three stages; 1. Pre-processing of input ECG signal (High-pass filter and Kalman filter), 2. Elimination of P wave (Difference Operation Method and Wavelet Transform), 3. Detection of QRS and T wave using Short Term Fourier Transform (STFT). Findings: The algorithm efficiency is evaluated with standard MIT-BIH Arrhythmia database. The Sensitivity (Se) and the Specificity (Sp) for QRS complex is found to be 99.59% and 99.53%, whereas for T wave it is of 99.50% and 99.44% respectively. Application/Scope: This algorithm could be implemented in real-time ECG analyzer for possible detection of ventricular chronic heart disease and may reduce the risk of sudden cardiac death.