Simulation analysis of conduction block in myelinated axons induced by high-frequency biphasic rectangular pulses.
Nerve conduction block induced by high-frequency biphasic rectangular pulses was analyzed using a lumped circuit model of the myelinated axon based on Frankenhaeuser-Huxley (FH) equations. At the temperature of 37 degrees C, axons of different diameters (2-20 microm) can be blocked completely at supra-threshold intensities when the stimulation frequency is above 10 kHz. However, at stimulation frequencies between 6 kHz and 9 kHz, both nerve block and repetitive firing of action potentials can be observed at different stimulation intensities. When the stimulation frequency is below 6 kHz, nerve block does not occur regardless of stimulation intensity. Larger diameter axons have a lower threshold intensity to induce conduction block. When temperature is reduced from 37 degrees C to 20 degrees C, the lowest frequency to completely block large axons (diameters 10-20 microm) decreased from 8 kHz to 4 kHz. This simulation study can guide future animal experiments as well as optimize stimulation waveforms for electrical nerve block in clinical applications.
Zhang
Xu
X
Department of Biomedical Engineering, Capital University of Medical Sciences, Beijing 100069, China.
Roppolo
James R
JR
de Groat
William C
WC
Tai
Changfeng
C
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001369:Axons / Q000502:physiology*; D003198:Computer Simulation; D004599:Electric Stimulation Therapy / Q000379:methods*; D006801:Humans; D008959:Models, Neurological; D009407:Nerve Block / Q000379:methods*; D009413:Nerve Fibers, Myelinated / Q000502:physiology*; D009431:Neural Conduction / Q000502:physiology*; D013813:Therapy, Computer-Assisted / Q000379:methods