Reduction of the number of electrodes in the measurement of body surface potential distribution.

: The number of electrodes required to reproduce a body surface potential map (BSPM) can be reduced by making use of the correlations among potentials measured at different sites on the body surface, as pointed out by Lux et al. in 1978. In the present paper, we have introduced two distinct methods which can be used to improve the accuracy of the potential estimation. In the first method, the BSPMs are divided into several classes according to the direction of the vectorcardiogram, while the temporal as well as the spatial correlations are taken into account in the second method. They are called the 'partition method' and the 'spatiotemporal correlation method', respectively. By means of the partition method using 40 electrodes, the estimation error becomes 75% of that estimated with the Lux method, which is equivalent to the Lux method with 47 electrodes. In other words, the partition method saves seven electrodes. When the electrodes are restricted on the chest, our methods are more effective. In particular, the partition method saves no less than 20 electrodes.