TOWARD FUNCTIONAL MAGNETIC STIMULATION (FMS) THEORY AND EXPERIMENT

This paper examines the use of magnetic fields to functionally stimula te peripheral nerves. All electric fields are induced via a changing m agnetic field whose flux is entirely confined within a closed magnetic circuit. Induced electric fields are simulated using a nonlinear boun dary element solver. The induced fields are solved using duality theor y. The accuracy of these predictions is verified by saline bath experi ments, Next, the theory is applied to the stimulation of nerves using small, partially occluded ferrite and laminated vanadium permendur cor es. Experiments demonstrate the successful stimulation of peripheral n erves in the African bullfrog with 11 mA, 153 mV excitations. These re sults offer a new vista of possibilities in the area of functional ner ve stimulation. Unlike functional electric stimulation (FES), FMS does not involve any half cell reactions, and thus would not have the comm ensurate FES restrictions regarding balanced biphasic stimulation, str ength duration balances, and oxidation issues, always exercising care that the electrodes remain in the reversible operating regime.