Abstract: In medical field for diagnosis of heart diseases electrocardiogram (ECG) is used and plays very important role. For better diagnosis a good quality ECG signal is requierd. Sometimes the problems occur is that noises corrupt the previously recorded ECG signals, significantly they are of two types:-electromyogram induced high-frequency noise, electrodes experience mechanical force, baseline wander this may be due to breathing process or the motion of the patients or the instruments. So that there will be wrong diagnosis. This paper introducing Emperical Mode Decomposition method for denoising of ECG, also introducing other methods for denoising included ecg analysis based on wavelet transform and modulus maxima, time-frequency dependent threshold, artificial neural networks and mathematical algorithm using window analysis.

Keywords: ECG, Window analysis, ECG Denoising, baseline wander, Artificial Neural Networks.