Figure 3.

The electrical field generated by the two electrodes. A constant 1 mA stimulation current was applied through the electrode, and the electrical field was calculated by the finite-element method. (A) The electrical field generated underneath the cathode of the patch electrode is shown. (B) The electrical field generated underneath one of the pin cathodes is shown. (C) Enlargement of the electrical field generated underneath one of the pin cathodes is shown. The spatial locations of the two axon models are illustrated by the two black lines. Note the spatially localized and the large depolarization generated by the pin electrode in epidermis primarily innervated by nociceptive nerve fibers. To see this figure in color, go online.