脑深部刺激电极的结构优化及其模拟分析

Computational Study for Stimulating Mechanism and the Optimal Geometry of Microelectrode in Deep-Brain Stimulation

为了进一步揭示脑深部电刺激术中微脑电极的结构与电刺激参数之间的关联作用对神经活动的抑制机理,利用有限元方法,研究微脑电极刺激触点结构对其作用区域的刺激范围和刺激程度.分析结果表明,电极触点阵列,特别是触点长度和触点间距是微脑电极结构尺寸中的关键因素,也是对脑电极作用区域影响最大的结构尺寸.电极触点长度或触点间距的增加将会增大对脑部的刺激强度和刺激范围,同时触点长度2倍于触点间距将使得脑部的刺激更加平稳、有效.电极触点长度和触点间距不仅直接影响其作用位置,而且影响其对脑部作用区域的刺激强度和刺激范围的变化规律.研究结果为微脑电极的构建提供了新的设计依据.

Deep brain stimulation has obtained an obvious effectiveness tor treating various locumotion disorder, but the stimulating mechanism by which these high frequency electrical pulses related to the geometry of electrode act on neuronal activity is unclear. The geometrical electrode model in deep-brain stimulation is established, and the analytic model of electric stimulating area based on the finite element technique is constructed to research electrode geometry, such as the stimulating point array architecture, how to affect the cerebral electric field. The computational results show that the stimulation intensity and action area increase gradually with the growth for the length and the gap of the electrode stimulating point; the stimulating stability approaches the when the length of stimulating point gets twice the length of the gap between the stimulating points. Therefore, the mode of the stimulating point array architecture enables to determine the electrode stimulating location in the deep brain, and plays an important role of the stimulation intensity and action area.