Bio-Signal Processing Using Digital Techniques

A simple digital technique is described which enables quick recording and analysis of bio-signals. Standard nuclear data acquisition techniques have been suitably adapted for on-line and off-line recording of bio-signals. A 1024-channel analyser with 50 MHz analog-to-digital converter data acquisition system is used for on-line recording. The data obtained from the data acquisition system is processed for detailed feature selection first by eliminating the extraneous noise by programmed digital filtering technique, by which the signals between 0-25 Hz are retained 25-50 Hz are attenuated (transfer function varies from 1.0-0.0) and signals above 50 Hz are eliminated. The smoothened data are differentiated and stored. The results of two leads. I and II, as evaluated by this processing and as evaluated by a physician agreed well. The coefficient of correlation was 0.99, the slope of regression line was (0.9918 ± 0.03) and intercept for the same was (-0.0007 ± 0.0098). These results are presented and discussed.