De-noising of ECG raw signal by cascaded window based digital filters configuration

An ECG is a graphic produced by an electrocardiograph that shows its significance in heart disease diagnostics, Bio-metric authentication, Human Computer Interface (HCI), etc. by recording the electrical activity of heart with respect to time. In each application noise elimination is initial step. Normally, the ECG signal is highly sensitive as it varies a lot with time. It is mainly corrupted by noises such as Power line Interference (PLI), Baseline wandering noise and noise due to muscle movements (EMG noise) during data acquisition. These noises add at different frequency range of ECG and make the signal analysis much tougher. Several researches with variety of processing methods have been taking place so as to retain the morphology of ECG signal. In this paper cascading of window based FIR filters are adopted for removing low frequency, mid frequency and high frequency noise from the noisy real ECG in a single step execution. Different ECG signals from MIT-BIH NSR, ECG ID databases are taken and the results were evaluated using MATLAB software. Finally performance measures of Signal to Noise Ratio (SNR), Mean Square Error (MSE) and Power Spectral Density (PSD) of de-noised ECG signal is calculated and compared with noisy real ECG.