Nerve-bundle conduction velocity distribution measurement and transfer function analysis

Human peripheral nerves are composed of thousands of individual nerve fibers whose signal conduction velocities vary from 0.2 to 100 m/s. Though good correlation exist between fiber velocity and the physiological function subserved by these fibers, considerable variation is found for specific end organs (20 to 40 m/s for a single muscle). Though clinical neurophysiologists have routinely measured the maximum conduction velocity of peripheral motor nerves for 30 years, it has not been possible to determine the velocity distributions. This report details a model and noninvasive methodology for motor axon conduction latency distribution mesurement. This distribution, proportional to velocity dispersion, possesses a low-pass filter characteristic which agrees with theoretical predictions and may be significant in some sensory and motor functions.