Arithmetic coding for ECG data compression

An electrocardiogram (ECG) entropy coding algorithm, arithmetic coding (AC), a lossless technique, has been used in a hybrid data compression arrangement where lossy techniques, turning point (TP) followed by the fan method, have previously been used. The evaluation was performed using the MIT/BIH arrhythmia database (360 Hz of sampling frequency and truncated to 8-bit resolution). An average compression rate of 10.88:1 (7.71:1 for the combination of TP and FAN, and 1.41:1 for AC) with an average percentage RMS difference (APRD) of 1.21% for normal and arrhythmic recordings was obtained. A clinical evaluation of the algorithm was performed using two groups of specialists, obtaining a 99% diagnostic sensitivity which shows that any distortion introduced by the ECG data compression procedure can be considered clinically negligible