论文标题
比较经颅电气和磁扰动的电场
Comparing the Electric Fields of Transcranial Electric and Magnetic Perturbation
论文作者
论文摘要
目前，通过准电磁均值（NIB）的无创脑刺激（NIB）由两种方法组成：磁感应方法（经颅磁扰动或TMP）和电接触方法（经颅电动扰动或TEP）。两种方法都通过产生的电场将夫妇与神经元系统相对。两种方法都必须伴随着与大脑中任何地方的大小更大的头皮电场。足够幅度的头皮电场可能会产生有害影响，包括周围神经刺激和加热，从而限制了脑电场的空间和时间特征。目前，电磁NIBS文献已经对TEP和TMP方法之间的差异产生了准确但非终止的理解。这项工作的目的是对这两种方法之间的差异有所广泛理解，这些方法可能会为新型TEP或TMP方法打开门，并在可能的情况下在两种方法之间转换进步。本文采用三个壳球形导体头模型来计算一般的分析结果，显示了脑电场的空间尺度之间的关系，并且：（1）两种方法的头皮与脑电场均衡器电场比和（2）TEP-TEP-TEP-TMP均值均值头皮均值电场均衡电场比，在深度上相似的电场。给出的最普遍的结果是，对于深度相似的电场，头皮均方体电场的TEP与TMP比率渐近极限。这些比率的具体示例计算也用于典型的TEP电极和TMP线圈配置。尽管与TEP相比，TMP具有有利的于点电场比率，而该优势的成本是在这项工作中短暂阐明的。
Noninvasive brain stimulation (NIBS) by quasistatic electromagnetic means is presently comprised of two methods: Magnetic induction methods (Transcranial magnetic perturbation or TMP) and electrical contact methods (Transcranial electric perturbation or TEP). Both methods couple to neuronal systems by means of the electric fields they produce. Both methods are necessarily accompanied by a scalp electric field which is of greater magnitude than anywhere within the brain. A scalp electric field of sufficient magnitude may produce deleterious effects including peripheral nerve stimulation and heating which consequently limit the spatial and temporal characteristics of the brain electric field. Presently the electromagnetic NIBS literature has produced an accurate but non-generalized understanding of the differences between the TEP and TMP methods. The aim of this work is to contribute a generalized understanding of the differences between the two methods which may open doors to novel TEP or TMP methods and translating advances, when possible, between the two methods. This article employs a three shell spherical conductor head model to calculate general analytical results showing the relationship between the spatial scale of the brain electric fields and: (1) the scalp-to-brain mean-squared electric field ratio for the two methods and (2) TEP-to-TMP scalp mean-squared electric field ratio for similar electric fields at depth. The most general result given is an asymptotic limit to the TEP-to-TMP ratio of scalp mean-squared electric fields for similar electric fields at depth. Specific example calculations for these ratios are also given for typical TEP electrode and TMP coil configurations. While TMP has favorable mean-squared electric field ratios compared to TEP this advantage comes at an energetic cost which is briefly elucidated in this work.
