Chen Yongjian, Akutagawa Masatake, Katayama Masato, Zhang Qinyu, Kinouchi Yohsuke
Graduate School of Advanced Technology and Science, The University of Tokushima, Japan.
Annu Int Conf IEEE Eng Med Biol Soc. 2008;2008:1879-82. doi: 10.1109/IEMBS.2008.4649552.
In this paper we describe an Independent Component Analysis (ICA) method for computing the brain signals of unknown source parameters for the inverse problem. First, a method is applied to estimate the number of dipoles beforehand and reduce dimensionality which can reduce the ICA complexity and improve the unmixing accuracy. We apply Blind Source Separation (BSS) for separating multichannel EEG evoked by multiple dipoles into temporally independent stationary sources. For every independent source, we are able to determine the electrode potentials evoked by every dipole separately by the projection of independent activation maps back onto the electrode arrays. Then for every set of electrode potentials, a source localization procedure is performed which only involves searching for one dipole, thus dramatically reducing the search complexity. In the paper, it is explored that the possibility of applying ICA for EEG multiple dipoles localization when the data are corrupted by additive noise. Furthermore, we also give the relationship of unmixing accuracy, distance between dipoles and dipoles moment movements.
在本文中,我们描述了一种用于计算逆问题中未知源参数脑信号的独立成分分析(ICA)方法。首先,应用一种方法预先估计偶极子数量并降低维度,这可以降低ICA的复杂度并提高分离精度。我们应用盲源分离(BSS)将多个偶极子诱发的多通道脑电图分离为时间上独立的平稳源。对于每个独立源,我们能够通过将独立激活图投影回电极阵列,分别确定每个偶极子诱发的电极电位。然后,对于每组电极电位,执行一个源定位过程,该过程仅涉及搜索一个偶极子,从而显著降低搜索复杂度。本文探讨了在数据被加性噪声破坏时,将ICA应用于脑电图多偶极子定位的可能性。此外,我们还给出了分离精度、偶极子之间的距离和偶极子矩运动之间的关系。