高分辨脑电图的理论研究  

Theoretical Studies on High-resolution EEG

作　　者：李勇[1] 高小榕[1] 杨福生[1] 高上凯[1] 马信山[1] 

机构地区：[1]清华大学电机系,北京100084

出　　处：《中国生物医学工程学报》2005年第1期59-65,共7页Chinese Journal of Biomedical Engineering

基　　金：国家自然科学基金重点资助项目 (5 993 7160 )。

摘　　要：高分辨脑电图是一种由头皮测量到的电位估算出皮层电位分布的方法 ,本研究对这一方法进行了较详细的理论分析。首先证明了当整个头部的外表面电位分布都己知时 ,在介质电导率各向同性头模型下 ,由于皮层和头皮之间的区域是无源区 ,因此皮层电位是惟一确定的。其次 ,考虑到在实际中只能够测量到头皮上有限个电极上的电位 ,本研究提供了一种方法来寻找电位从皮层表面到头部外表面的空间传递系数 ,并根据它来判断利用高分辨率脑电估算出的皮层电位可信度比较高的区域。最后 ,本研究在三层各向同性同心球模型下 ,推算出皮层的点电位传递到头部外表面电位的空间传递函数的解析表达式。The uniqueness and confident area of the high-resolution electroencephalogram (HREEG), which enhances the poor spatial resolution of the scalp EEG recording, have been investigated from the theoretical viewpoint. It was proved that because the region bounded by the scalp and the cortex was passive, the cortical potential was unique in a realistic, homogeneous head model when the entire scalp potential was known. However only the potential of finite electrodes rather than a continuous set of points on the scalp could be measured, so the cortical potential in HREEG was not unique. The potential spread function from the cortex to the scalp was derived in this paper. The confident area on the cortex. estimates by HREEG was also defined based on the funotion. The analytic solution of the transfer function in a 3-shell homogeneous head shape model has also been derived. Variation in skull conductivity and scalp thickness was found to exert a quantitative and qualitative effect on the potential transfer function.

关 键 词：高分辨脑电图 惟一性 空间传递函数 

分 类 号：R318.19[医药卫生—生物医学工程]