Figure 2: Electrode configuration. Electrode 1—position so that the edge of electrode was 6–8 cm on the left of the navel and 3-4 cm above the navel; Electrode 2—position so that the edge of electrode was 3-4 cm on the left of the navel and 3-4 cm above the navel; Electrode 5—position so that the edge of electrode was 3-4 cm left of the navel and 3-4 cm below the navel; Electrode 7—position so that the edge of electrode was 3-4 cm left of the navel and 6–8 cm below the navel; Electrodes 4 and 1, Electrodes 3 and 2, Electrodes 6 and 5, and Electrodes 8 and 7 are symmetrical about the midline; reference: Electrode R—on the left of ilium; ground: Electrode G—on the right of ilium.