Suh Hyun Sang, Lee Won Hee, Cho Young Sun, Kim Ji-Hwan, Kim Tae-Seong
Department of Biomedical Engineering, Kyung Hee University, Yongin, Gyeonggi, Republic of Korea.
Annu Int Conf IEEE Eng Med Biol Soc. 2010;2010:2053-6. doi: 10.1109/IEMBS.2010.5626502.
For effective stimulation with tDCS, spatial focality of induced electrical field (EF) is one of the important factors to be considered. Recently, there have been some studies to improve the spatial focality via different types of electrodes and their new configurations: some improvements using ring electrodes were reported over the conventional pad electrodes. However, most of these studies assumed isotropic conductivities in the head. In this work, we have investigated the effect of tissue anisotropy on the spatial focality of tDCS with the 4+1 ring electrode configuration via a 3-D high-resolution finite element (FE) head model with anisotropic conductivities in the skull and white matter. By examining the profiles of the induced EF from the head models with isotropic and anisotropic conductivities respectively, we found that the spatial focality of the induced EF significantly drops and get diffused due to tissue anisotropy. Our analysis suggests that it is critical to incorporate tissue anisotropy in the stimulation of the brain via tDCS.
为了通过经颅直流电刺激（tDCS）实现有效刺激，感应电场（EF）的空间聚焦性是需要考虑的重要因素之一。最近，有一些研究通过不同类型的电极及其新配置来提高空间聚焦性：与传统的平板电极相比，使用环形电极有一些改进。然而，这些研究大多假设头部电导率是各向同性的。在这项工作中，我们通过一个在颅骨和白质中具有各向异性电导率的三维高分辨率有限元（FE）头部模型，研究了组织各向异性对采用4 + 1环形电极配置的tDCS空间聚焦性的影响。通过分别检查具有各向同性和各向异性电导率的头部模型所感应的EF分布，我们发现由于组织各向异性，感应EF的空间聚焦性显著下降并扩散。我们的分析表明，在通过tDCS刺激大脑时考虑组织各向异性至关重要。
