ECG signal compression using hybrid 1D and 2D wavelet transform

In this paper, we present a compression technique for Electrocardiogram (ECG) signals. Different data compression techniques are available. As the ECG data to be handled is huge, we must use an appropriate compression technique. When we try to compress an ECG signal, the clinically important features of the signal must be properly retained which are useful to the doctors for proper diagnosis. We have proposed a new compression technique, which uses transform based with hybrid stage. In this method, a Discrete Cosine Transform (DCT) stage is combined with 1D or 2D discrete wavelet transforms (DWT) respectively. The hybrid stage is suitable for compressing the complete ECG signal as well as the QRS complex. The compression ratio (CR) and Percent Root Mean Square Difference (PRD) are controlled by proper selection of the threshold value. The threshold value has better hold on the CR.