ECG DATA COMPRESSION USING SAPA TECHNIQUES

Abstract

A good number of techniques have been developed during the last three decades for the compression of ECG signal. The data compression helps . in handling the large amount of ECG information efficiently. It' reduces the requirement for storage of ECG signals in computers. and transmission ..of ECG signal over telemetering channels. In present work, detailed study has been carried out on scaii along polygonal , approximation (SAPA) and thereafter improvements have been made by incorporating cycle-to-cycle compression technique with SAPA algorithms. There are three SAPA techniques, namely SAPA I, SAPA II and SAPA III. These algorithms are -called "Scan-along" in the sense that they carry on the compression process in real time and follow the presence of the electrocardiogram continuously. The _algorithms are based on the minimum perimeter polygonal approximation which is used for the digitized signals. Sufficient improvement has been obtained in compression ratio by introducing cycle-to-cycle (CTC) compression with SAPA techniques. The techniques have been tested on . all 12-leads of ECG signal. The results are encouraging and promises wider scope for application in real time ECG data compression. The software has been developed in "C" language and entire work has been carried out on TATA ELXI in UNIX environment