应用于脑电场的新型等效源法的正演理论

The forward calculation of the new equivalent source method applied to brain electric field

将新型等效源法引入脑电场电位的计算,视激励源为偶极子,实现真实电源既可以在真实的头模型中产生电位,也可以在均质无界空间中产生电位。从无界空间中三维拉普拉斯方程解的球形等效源的有限级数项表达式可见,该半解析方法克服了头模型对电位分布的干扰,在无界空间中计算出的电位是电源的裸表现。本文利用等效分布源理论推导出无界空间中任意偶极子源的球形等效源的正演理论公式,为高分辨脑电地形图技术中的重构皮层电位提供了一种方法。

The new equivalent source method is applied to calculate the potential of brain electric field. Under the dipole regarded as stimulated source, real electrical source produce potential not only in real head model, but also in homogeneous limitless space. According to expression of spheric equivalent source of three-dimensional Laplace equation solution in limitless space, the self-resolution method has overcame the interference of head model on the potential distribution, and the potential is the exposed expression of source. The paper uses the equivalent distribution source theory to deduce the forward theory of spheric equivalent source of random dipole in limitless space. The new equivalent source method is a new one for reconstructing the cortex potential in high-resolution EEG mappings.