Projected current density comparison in tDCS block and smooth FE modeling.
Projected current density comparison in tDCS block and smooth FE modeling.
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DOI：
10.1109/embc.2016.7591623
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发表时间：
2016-08
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影响因子：
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通讯作者：
Sadleir RJ
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文献类型：
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作者：
Indahlastari A;Chauhan M;Sadleir RJ
比较了经颅直流电刺激（tDCS）正演模型在人脑中的电流密度分布和投影电流密度计算。块模型由MRI体素分辨率直接构建，在c中进行模拟。平滑模型采用递归高斯滤波进行边界平滑处理，在COMSOL中进行模拟。与块模型相比，添加了三个平滑级别以确定它们对电流密度分布的影响。计算前颞上回（ASTG）、海马（HIP）、额下回（IFG）、枕叶（OCC）和中央前回（PRC）的中位电流密度百分比差异，并根据基线值进行归一化。三种标准电极蒙太奇：F3-RS， T7-T8和Cz-Oz的中位电流密度差异最大为±20%。此外，每个蒙太奇靶脑结构的中位电流密度百分比差异在±7%以内。更高的平滑水平增加了T7-T8和Cz-Oz靶结构的电流密度中位数百分比差异。然而，虽然在每个蒙太奇中都显示出类似的趋势，但额外的平滑水平显示，它们的平滑效果与计算出的五种皮层结构中位电流密度之间没有明确的关系。最后，对于块状和光滑管道，重建投影电流密度的相对L2误差分别为17%和21%。总的来说，区块模型工作流可能是模拟tDCS增产的更有吸引力的替代方案，因为它的建模时间更短，并且不依赖于商业建模平台。
Current density distribution and projected current density calculation following transcranial direct current stimulation (tDCS) forward model in a human head were compared between two modeling pipelines: block and smooth. Block model was directly constructed from MRI voxel resolution and simulated in C. Smooth models underwent a boundary smoothing process by applying recursive Gaussian filters and simulated in COMSOL. Three smoothing levels were added to determine their effects on current density distribution compared to block models. Median current density percentage differences were calculated in anterior superior temporal gyrus (ASTG), hippocampus (HIP), inferior frontal gyrus (IFG), occipital lobes (OCC) and precentral gyrus (PRC) and normalized against a baseline value. A maximum of ± 20% difference in median current density was found for three standard electrode montages: F3-RS, T7-T8 and Cz-Oz. Furthermore, median current density percentage differences in each montage target brain structures were found to be within ± 7%. Higher levels of smoothing increased median current density percentage differences in T7-T8 and Cz-Oz target structures. However, while demonstrating similar trends in each montage, additional smoothing levels showed no clear relationship between their smoothing effects and calculated median current density in the five cortical structures. Finally, relative L2 error in reconstructed projected current density was found to be 17% and 21% for block and smooth pipelines, respectively. Overall, a block model workflow may be a more attractive alternative for simulating tDCS stimulation because involves a shorter modeling time and independence from commercial modeling platforms.