A computational study to evaluate the mechanism of selectivity in interferential current therapy

Interferential current therapy is a method of transcutaneous stimulation of deep tissues in which the undesirable activation of cutaneous nerves is minimized. While it is a well-known method in physiotherapy and diagnostic medicine, its selective property has been only described qualitatively in the literature. In this study, the effect of interferential stimulation on neural tissue was simulated to describe the exact mechanism of its selectivity. Two channel high frequency sinusoidal currents were applied to a spherical volume conductor model, and the responses of different neural fibers inside the sphere were analyzed. The results provided a quantitative description of the mechanism of selectivity by interferential currents based on high frequency block of neural fibers.