真实头模型中的多电流偶极子脑磁源定位

给出了真实头模型下多电流偶极子定位的通用公式,并对多种源的情况进行了计算机模拟,逆问题的求解采用全局优化与局域优化相结合的优化方法,在较强的噪声背景下得到了较好的定位结果.其中,在偶极子源较少时,采用了球对称导体模型与真实头模型相结合的混合模型,进一步提高了求解速度 关键词： 脑磁技术 真实头模型 多偶极子脑磁源 优化方法

The localization of multiple current dipoles in a realistic head shape model

The realistic head model has been used in magnetoencephalography (MEG) as an accurate forward model for calculating the external magnetic fields resulting from neural activity.In this paper,we present a general matrix formulation for calculating the localization of multiple dipoles in a realistic head model by means of boundary element method.In addition,using general optimal combined with local optimal method,we solve the inverse problem by computer simulation.We simulate from the simple one dipole situation to the complicated five dipoles situation.The results prove that our method is of validity.In order to improve the rapidity of convergence as well as keep the localization precision,we use spherically symmetric conductor model in the general optimal method step if there is only 1 or 2 dipoles.