Investigating the electromagnetic induction response of neurons on stimulus waveform shapes and coil geometries

The nervous system in humans operate based on electrical conduction through action potentials. So, when nerves are damaged, electrical pathways in the body are broken, which leads to the loss of muscle control and other bodily functions. To treat such patients, doctors at the Medical College of Georgia have carried out clinical studies that show damaged nerve function can be improved by electromagnetic induction. However, the interaction mechanism of how an induced electric field interacts with damaged nerves and its implication within a clinical setting is not fully understood. The goal of this project is to understand how optimizing the setup used to induce an electric field can affect the clinical treatment of a damaged nerve. Using a computational approach that models the nerves within the Hodgkin-Huxley paradigm and the electromagnetic interaction of the nerves with the Roth-Basser equation, we find that for the unmyelinated neurons there is a greater stimulus imparted to the nerve for long pulse durations. In addition a biphasic signal is not as effective as a monophasic signal. The geometry of the coil also affects the stimulus of the nerve with a circular coil geometry generating the largest impact. We also investigate the above effects for myelinated axons.