摘要
经硬脑膜对视皮层电刺激是治疗失明的新思路。为从理论上认识其作用机制,首先建立视皮层区域的有限元仿真模型,分析脑组织内电场分布,并用激活函数和组织活化区来表征外加刺激的作用效果;随后逐次改变单相脉冲的幅值、脉宽和频率,通过基波作用下组织活化区的变化来探讨不同刺激参数对结果的影响。仿真结果显示,经硬脑膜可以实现对视皮层的有效刺激,只是所需刺激强度比直接皮层刺激约高30倍;多电极刺激模式下,只要电极间距超过5 mm,电极间的影响可忽略不计;降低幅值、脉宽和频率等参数,可以改善单相方波脉冲的刺激效果,其中幅值的减小对空间分辨率的提高效果最为显著。所得结论对实验具有一定指导意义。
The epidural electrical stimulation applied on the visual cortex is a new therapy for blindness treatment.In order to learn its mechanism theoretically,a finite element model of the visual cortex was developed,and the electrical field distribution was calculated,then the activating function and volume of tissue activated（VTA） were used to characterize the stimulus effect on neural activations.Furthermore,the changes of VTA under fundamental component of the original monophasic pulse were analyzed,and the parameters of amplitude,frequency,and duration were evaluated.The simulation results indicated that visual prosthesis based upon epidural electrical stimulation was possible,but needed about 30 times of stimulus intensities greater than cortex stimulation.For multi-electrodes stimulation,the stimulation effect of each electrode would be independent if the distance between each other was more than 5 mm.Moreover,decrease of amplitude,frequency and duration of stimulus would improve the stimulation efficiency significantly,and the reduction of amplitude was most efficient for improving spatial resolution.The present results provided some theoretical guidance for the design of experiments.
出处
《中国生物医学工程学报》
CAS
CSCD
北大核心
2010年第4期557-563,共7页
Chinese Journal of Biomedical Engineering
基金
国家高技术研究发展(863)计划(2007AA04Z324)
重庆市自然科学基金(CSTC2007BB5147,CSTC2006BB2142)
重庆大学“211工程”三期创新人才培养计划建设项目(S-09104)
关键词
硬脑膜
视皮层
激活函数
组织活化区
dura mater
visual cortex
activating function
volume of tissue activated
