Simulation analysis of extracellular selective stimulation of optic nerve with new helix electrode / 国际生物医学工程杂志

ABSTRACT

ObjectiveElectric stimulation of the central nervous system has been served as a treatment method for variety of neurological,psychiatric and sensory disorders.Despite considerable success in some applications,current stimulation techniques offer little control over which neuronal targets are activated by stimulation.This study aimed to present a new shape self-adaptive helix electrode for selective activation of optic nerve.MethodsThe geometric model of optic nerve and new helix electrode was elaborated with COMSOL Multiphysics.The new helix electrodes consist of silicone helix frame,which acted as support and insulation,and platinum contacts embedded within the frame.The activating function (AF) was introduced to characterize the stimulation effects,and the selectivity of activating optic nerve fascicle with new helix electrode was simulated by COMSOL Multiphysics,taking into account the variations of electrode contact locations.ResultsAssuming normalized AF threshold was 0.1 V/m2,the ratio difference of AF over threshold between new helix electrode and traditional electrode was only 1.2410％.With contacts in two ends of helix electrode closer to the middle contact,the small nerve fascicle was first activated and then the large one.ConclusionThe results show that the new helix electrodes have the same stimulation effects as that of traditional cuff electrodes.The new helix electrodes can selectively activate optic nerve fascicle with variations of electrode contact locations.