Haueisen J, Ramon C, Eiselt M, Brauer H, Nowak H
Biomagnetisches Zentrum, Friedrich-Schiller-Universität Jena, Germany.
IEEE Trans Biomed Eng. 1997 Aug;44(8):727-35. doi: 10.1109/10.605429.
Modeling in magnetoencephalography (MEG) and electroencephalography (EEG) requires knowledge of the in vivo tissue resistivities of the head. The aim of this paper is to examine the influence of tissue resistivity changes on the neuromagnetic field and the electric scalp potential. A high-resolution finite element method (FEM) model (452,162 elements, 2-mm resolution) of the human head with 13 different tissue types is employed for this purpose. Our main finding was that the magnetic fields are sensitive to changes in the tissue resistivity in the vicinity of the source. In comparison, the electric surface potentials are sensitive to changes in the tissue resistivity in the vicinity of the source and in the vicinity of the position of the electrodes. The magnitude (strength) of magnetic fields and electric surface potentials is strongly influenced by tissue resistivity changes, while the topography is not as strongly influenced. Therefore, an accurate modeling of magnetic field and electric potential strength requires accurate knowledge of tissue resistivities, while for source localization procedures this knowledge might not be a necessity.
脑磁图（MEG）和脑电图（EEG）建模需要了解头部的活体组织电阻率。本文旨在研究组织电阻率变化对神经磁场和头皮电势的影响。为此，采用了一个具有13种不同组织类型的高分辨率有限元方法（FEM）模型（452,162个单元，分辨率为2毫米）对人头进行建模。我们的主要发现是，磁场对源附近的组织电阻率变化敏感。相比之下，表面电势对源附近和电极位置附近的组织电阻率变化敏感。磁场和表面电势的大小（强度）受组织电阻率变化的强烈影响，而地形则受影响较小。因此，对磁场和电势强度进行精确建模需要准确了解组织电阻率，而对于源定位程序来说，这一知识可能并非必需。
