Vanrumste B, Van Hoey G, Van de Walle R, D'Havé M, Lemahieu I, Boon P
Department of Electronics and Information Systems, Ghent University, Belgium.
Med Biol Eng Comput. 2000 Sep;38(5):528-34. doi: 10.1007/BF02345748.
An examination is made of dipole location errors in electroencephalogram (EEG) source analysis, due to not incorporating the ventricular system (VS), omitting a hole in the skull and underestimating skull conductivity. The simulations are performed for a large number of test dipoles in 3D using the finite difference method. The maximum dipole location error encountered, utilising 27 and 53 electrodes is 7.6 mm and 6.1 mm, respectively when omitting the VS, 5.6 mm and 5.2 mm, respectively when neglecting the hole in the skull, and 33.4 mm and 28.0 mm, respectively when underestimating skull conductivity. The largest location errors due to neglecting the VS can be found in the vicinity of the VS. The largest location errors due to omitting a hole can be found in the vicinity of the hole. At these positions the fitted dipoles are found close to the hole. When skull conductivity is underestimated, the dipole is fitted close to the skull-brain border in a radial direction for all test dipoles. It was found that the location errors due to underestimating skull conductivity are typically higher than those found due to neglecting the VS or neglecting a hole in the skull.
本文研究了在脑电图（EEG）源分析中，由于未纳入脑室系统（VS）、遗漏颅骨孔洞以及低估颅骨电导率而导致的偶极子定位误差。使用有限差分法对大量三维测试偶极子进行了模拟。当忽略VS时，使用27个和53个电极时遇到的最大偶极子定位误差分别为7.6毫米和6.1毫米；当忽略颅骨孔洞时，分别为5.6毫米和5.2毫米；当低估颅骨电导率时，分别为33.4毫米和28.0毫米。由于忽略VS导致的最大定位误差出现在VS附近。由于遗漏孔洞导致的最大定位误差出现在孔洞附近。在这些位置，拟合的偶极子靠近孔洞。当低估颅骨电导率时，对于所有测试偶极子，偶极子在径向方向上靠近颅骨-脑边界拟合。研究发现，由于低估颅骨电导率导致的定位误差通常高于因忽略VS或遗漏颅骨孔洞而产生的误差。
