Figure 6.

Performance metrics of the seven TMS coil configurations shown in Figure 2 for stimulation target depths of 2–6 cm: (a) maximum electric field in the superficial cortex relative to neural activation threshold, max(∣E_{2 cm}∣)/E_th; (b) directly activated brain volume, V_A; and (c) energy delivered to the coil assuming E_th = 1 V cm⁻¹, W. The curves for coils with circular and double loop electric field patterns are shown in red and black, respectively.