Circuit and volume conductor models of transcutaneous electrical stimulation

Electrical stimulation of peripheral nerves is a widespread technique for the treatment of neurological diseases and disorders. However, peripheral stimulation typically requires surgical implantation of an electrode and a pulse generator. Transcutaneous stimulation with an external electrode and pulse generator could provide a noninvasive alternative for nerve stimulation. In this study we implemented a lumped parameter electrical circuit and a distributed parameter volume conductor model to quantify the distribution of potentials in the tissue, including frequency-dependent dielectric properties, during transcutaneous electrical stimulation with a very high frequency sinusoidal carrier and rectangular envelope pulse. The circuit model exhibited a highpass behavior with a corner frequency around 100 kHz, whereas the volume conductor model revealed maximum penetration of the potential for high frequency signals. Taken together, these results suggest that incorporating high frequency components in voltage-controlled transcutaneous stimulation may make it possible to reach deeper structures in the tissue, such as nerves.