摘要
为了研究电极与神经作用机制,优化电极设计和指导假体的应用,有限元方法用于分析螺旋袖套电极刺激视神经产生的电场空间分布。建立了圆柱形的视神经模型,并考虑电极结构和脑脊液(CSF)厚度变化对刺激效果的影响。选择合适的网格剖分和边界条件,应用COMSOL Multiphysics有限元软件,计算电极的三维电场。结果表明,在相同的刺激条件下,纵向三电极结构比双电极结构(电极分别位于神经干对侧)的电流密度值要大,但双极结构所需引线少,植入简单,易于临床应用。应用参数扫描的方法仿真表明,由于CSF层的电导率比其他组织大,随着CSF层厚度增加,电极电场分布范围更大,但对电流的散射阻碍使神经刺激效果变差。
In order to study the underlying electroue-nciw ,- guide the prosthesis application, we applied finite element method to analyze the spatial distribution of electric field generated by optic nerve electrical stimulation with spiral cuff electrode. A macroscopic cylindrical model o{ optic nerve was elaborated, taking into account of electrode contact configurations and possible variations of the thickness of eerebrospinal fluid （CSF）. By building an appropriate mesh on this model and under some boundary conditions, the finite element method was applied to compute the 3D electric field generated by the electrode with finite element software COMSOL Multiphysics. The stimulation results indicated that, under the same conditions of stimulation, the longitudinal tripolar electrode structure could generate larger current density than that of biopolar electrode struc- ture （located in the opposite of nerve trunk）, However biopolar electrode structure requirs less leads, and is more easily implanted. By means of parametric sweep, the results suggest that, with the increase of the CSF thickness and a higher conductivity of CSF than those of other tissues, the distribution of electric field generated by electrodes is extended but scattered, and the diffuse current distribution makes nerve stimulation less effective.
出处
《生物医学工程学杂志》
EI
CAS
CSCD
北大核心
2012年第5期820-824,共5页
Journal of Biomedical Engineering
基金
973计划项目资助(2005CB724302)
国家自然科学基金资助项目(30870649)
关键词
视神经
螺旋袖套电极
有限元
脑脊液
胞外电刺激
Optic nerve
Spiral cuff electrode
Finite elements method
Cerebrospinal fluid （CSF）
Extracellular e-lectric stimulation
