Figure 14

Contour map of joint induced voltage gradients for figure of eight coils in a region of interest close to the z-axis perpendicular to the body surface and passing through the midpoint between coil centers (crux of the figure of eight). In this special case results for two simple circular coils (details as in Figure 5) are superimposed to give the joint field in the region of interest ± 0.9 coil radius from the z-axis to estimate the net induced EMF. The width of the contour map is 1.8 coil radii and the height is one coil radius. Contour intervals are 20 V/m apart. The target region of stimulation is centered about 0.4 coil radii from the surface plane.