The processed map of the body surface potential

As the processed maps, the variance map and the residue which was the ratio of the nondipolar cardiac field were introduced. The variance map was made from the root mean square of the distance from the mean value of QRS, T or QRST. The variance map may be useful to find the area of the peak variation of QRS, T or QRST on the body surface. The residue is the expression how much was the nondipolar component included in the body surface potentials. This may be relevant to detect the abnormal cardiac potentials included in the body surface potentials.