Optimal Stimulus Electrode Dipole Orientation

Robert B. Szlavik, McMaster University
Hubert De Bruin, McMaster University

Article comments

Copyright © 1999 Canadian Medical and Biological Engineering Society. Posted with permission from CMBES.

NOTE: At the time of publication, the author Robert Szlavik was not yet affiliated with Cal Poly.

Abstract

The elicited M-Wave that results from the surface stimulation of the median nerve is highly dependent upon the geometric orientation of the stimulus electrode dipole. This phenomenon could make standardization of M-Wave measurements between tests performed on a single subject problematic. We present an experimental paradigm that illustrates this variability in terms of an estimate of the slope of the M-Wave peak potential versus stimulus current amplitude and the minimum stimulus current required to consistently elicit a minimal response. The design of an automated instrument for selecting the optimal stimulus electrode dipole orientation based on the electrode orientation experiment is proposed.