脑电深、浅层偶极子源的一种分离方法

从头皮测到的脑电信号中把由深层源和浅层源产生的部分分离开，并根据深层源产生的部分观察大脑内部深层的电活动细节，在理论和临床上都有重要意义。通过分析比较深、浅脑电偶极子在头皮一组电极上所产生脑电的空间频率，提出了利用脑电的空间高频分量定位浅层源，进而把浅层源产生的电位从脑电中分离出去的方法，并且将Ｍａｒ－ｑｕａｒｄｔ优化算法由空域推广到了空间频率域。仿真实验表明利用高频分量在空频域求逆可以较准确地定位浅层源，从而有效地把浅层源和深层源的贡献区分开来。

Method to separate deep and shallow dipole sources of the electroencephalogram

To separate the electroencephalogram (EEG) measured on the scalp into the parts generated by deep and shallow electrical sources respectively is a subject of importance both theoretically and clinically, because we can then find in more detail the electrical activities in the deep parts of the brian. Based on the analysis of the spatial frequency of EEG measured by a set of electrodes distributed on the scalp, a method is proposed to solve this problem, which includes two steps. For the first step, the shallow dipoles are localized by the higher spatial frequency components and for this purpose, a frequency domain Marquardt algorithm is derived. Then, in the second step, the parts of electrical activities contributed by the deeply located dipoles are revealed after subtraction of the parts of EEG generated by shallow dipoles from the measured EEG. comjputer simulations show that the localization of shallow dipoles by inversion in frequency domain with higher frequency components are quite accurate, and thus the potentials generated by deep and shallow dipoles can be separated effectively.