脑磁源的定位研究

在脑电脑磁研究中，常将大脑视为一电磁系统，利用准静态近似下的麦克斯韦方程，可以发现代表脑神经元活动的原在电流密度与脑外磁场之间呈线性关系。在高斯哭喊杨存在的情况下，采用极大似然估计理论，讨论了一种基于脑磁场时域－罕注解磁源定位问题的一般方法。球对称导体模型下的模拟计算表明，这一方法是有效的。对于考虑真实头模型下的磁源定位问题求解磁源定位，提出了一种联合使用脑磁脑电数据的近似方法。

RESEARCH ON THE LOCALIZATION OF MAGNETIC SOURCESIN THE BRAIN

The brain is often considered as an electromagnetic system on MEG/EEG studies. From quasistatic approximation of Maxwell's equations, it can be found that the relationship between the primary current density representing the cerebral neuron activities and magnetic field outside the head is linear. A general method, which can be used to locate the magnetic sources in the brain from spatio-temporal MEG data, is discussed. The method is based on maximum likelihood estimation, when the noise is Gaussian. Computer simulation using spherically symmetric conductor head model demonstrates that the method is effective. Considering the real head-shaped model, an approximate method based on the union of MEG and EEG data is also presented.