Experimental tests of EEG source localization accuracy in spherical head models
Experimental tests of EEG source localization accuracy in spherical head models
复制标题
DOI：
10.1016/s1388-2457(00)00488-0
复制
发表时间：
2001-01-01
影响因子：
4.7
通讯作者：
Blume, H
中科院分区：
文献类型：
--
作者：
Cuffin, BN;Schomer, DL;Blume, H
目的：利用脑电数据可以计算出大脑中电源的位置。然而，这些计算的准确性是不为人所知的，因为它通常是不可能的计算源的位置与实际位置进行比较，因为几乎没有准确的位置信息是关于大多数源在brain.Methods：在这项研究中，在已知位置的源创建通过注入电流到植入在人类受试者的大脑中的电极。植入和头皮EEG电极的位置由CT确定。由这些偶极源产生的EEG信号用于计算包含大脑、颅骨和头皮层的球形头部模型中的源位置。脑和头皮层具有相同的电导率，同时使用脑和头皮电导率的1/80、1/40和1/20的3种不同的颅骨电导率比率。结果：当颅骨电导率比为1/40时，177个源的平均定位误差为10.6（SD = 5.5）mm。其他比率的平均误差仅大几毫米。在大脑中上级位置的108个源的平均定位误差为9.2 69个次源定位的平均误差为12.8（6.2）mm，深源和浅源的定位精度无显著差异。这些结果表明，使用球形头部模型可以实现的最佳平均定位约为10 mm。定位精度(C)2001爱思唯尔科学爱尔兰有限公司保留所有权利。
Objectives: The locations of electrical sources in the brain can be calculated using EEG data. However, the accuracy of these calculations is not well known because it is usually not possible to compare calculated source locations with actual locations since little accurate location information is available about most sources in the brain.Methods: In this study, sources at known locations are created by injecting current into electrodes implanted in the brains of human subjects. The locations of the implanted and scalp EEG electrodes are determined from CTs. The EEG signals produced by these dipolar sources are used to calculate source locations in spherical head models containing brain, skull, and scalp layers. The brain and scalp layers have the same electrical conductivity while 3 different skull conductivity ratios of 1/80th, 1/40th, and 1/20th of brain and scalp conductivity are used. Localization errors have been determined for 177 sources in 13 subjects.Results: An average localization error of 10.6 (SD = 5.5) mm for all 177 source was obtained for a skull conductivity ratio of 1/40. The average errors for the other ratios an only a few millimeters larger. The average localization error for 108 sources at superior locations in the brain is 9.2 (4.3) mm. The average error for 69 inferior location sources is 12.8 (6.2) mm. There are no significant differences in localization accuracy for deep and superficial sources.Conclusions: These results indicate that the best average localization that can be achieved using a spherical head model is approximately 10 mm. More realistic head models will be required for greater localization accuracy. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.