University of Utah Undergraduate Research Abstracts, Volume 3, Spring 2003

Magnetic Stimulation of Peripheral Nerves

MAGNETIC STIMULATION OF PERIPHERAL NERVES EricTuday Senior Bioengineering Rockhopperl [e-mail] Faculty Sponsor: Ken Horch Dept. of Bioengineering [e-mail] It is possible to stimulate the peripheral nervous system using a magnetic coil. Observations have been made that suggest the magnetic coils are able to produce an action potential that travels in only one direction. This is unique because conventional stimulation creates an action potential that propagates in both directions from the site of stimulation. However, there is no quantitative proof of the existence of unidirectional action potentials. The objective of this project is to enable the collection of quantifiable data to prove the existence of unidirectional action potentials using human subjects. The data is collected as surface recordings of electrical activity in the somatosensory cortex region of the brain and the forearm muscles. Electromyographic and somatosensory evoked potential recordings are made while a subject is being stimulated with a magnetic coil. The coil is maneuvered to a location where it is thought to produce unidirectional action potentials. The coil is then locked into place with a mechanical system, the arm is stimulated with the coil, and then the data is acquired by a computer. The raw data is collected with Labview and analyzed with Matlab. The data recording setup was proven to work by collecting and analyzing sample data. The data collected to date suggests that the unidirectional action potentials might exist, but it is still subject to argument. Twenty more subjects are scheduled to be tested and the data collected will be able to confirm (or contradict) our hypothesis. 74