Figure 2

BSGM array placement and EGG electrode identification procedure. The main electrode was selected as the electrode along the dotted line closest to the midpoint between the umbilicus and xiphoid (blue, left). The reference electrode was selected as the electrode three to the right in the same row as the main electrode (blue, right). If either of those electrodes had impedance > 500 kilohms, the next closest electrodes were selected (green).