Electroencephalography and its Inverse Analysis
Yoshiwo Okamoto, Ikuo Homma · IEEJ Transactions on Electronics Information and Systems · 2002
Electroencephalography (EEG) is a noninvasive, nonrestrictive and low-cost means of estimating brain activities with time resolution less than millisecond. Moreover, because of the remarkable progress in computer technology, it is possible to take the conductivity inhomogeneity into account in computing potential distributions, and hence the characteristic of being sensitive to low-conductive tissues such as skull is no longer a serious drawback of EEG In this paper, after a short description of the generation mechanisms of EEC., major methods for solving the inverse problem are introduced. The inverse analysis is based on the forward solutions, namely we need a means to calculate potential distribution on the scalp surface generated by EMF sources in the brain. Here, the construction process of a multi-shell head model is described, and an efficient forward technique suitable for such a head model is introduced.