Fig. 5

The upper panel is an example of a typical ECG record obtained from a different subject of Fig. 4 (22 years). The middle panel a shows an expanded record in time from 110 to 120 s in the upper record, and the lowest panel b is its corresponding record of a simultaneously measured by the direct method using spot-electrodes. Circular marks in each a and b indicate the ECG-R waves. The vertical axis in each record is shown as arbitrary unit (a.u.)