A Holter-tape analyzer employing circuits for calculation of correlation coefficients

An analyzer for ventricular premature contraction (VPC) arrhythmias was developed. At 60 times real time, the analyzer processes the Holter tape in which the long-term ambulatory electrocardiogram was recorded. Template matching algorithm using Pearson product-moment correlation coefficient is employed. A microprocessor controls the analyzer. Circuits for calculation of correlation coefficients were developed to support insufficient computing speed of the microprocessor. Evaluation study shows that the sensitivity for detecting the normal QRS complexes and the VPCs were 98.9% and 99.4%, and that the specificity for these were 97.5% and 98.4%. Algorithm for high-speed calculation of correlation coefficients is also considered.