Head phantoms for electroencephalography and transcranial electric stimulation: a skull material study
Head phantoms for electroencephalography and transcranial electric stimulation: a skull material study
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DOI：
10.1515/bmt-2017-0069
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发表时间：
2018-12-01
影响因子：
1.7
通讯作者：
Haueisen, Jens
中科院分区：
文献类型：
--
作者：
Hunold, Alexander;Strohmeier, Daniel;Haueisen, Jens
物理头部模型允许在经颅电刺激期间评估脑电图和电刺激曲线中的源重建程序。头部中的体积传导受到颅骨的强烈影响，颅骨代表主要的传导屏障。因此，对其特征进行真实建模对于体模开发非常重要。在本研究中，我们提出了塑性粘土作为材料的头骨模型在幻影。我们分析了五种粘土类型，粒度和耐火粘土的分数各不相同，每种粘土的烧制温度从550摄氏度到950摄氏度。我们研究了标准化的粘土样品浸泡在0.9%的氯化钠溶液与时间分辨四点阻抗测量的电导率。为了测试粘土模型的可重复使用性，在通过在去离子水中冲洗5小时来清洁样品之后重复这些测量。我们发现时间依赖性的阻抗变化约5分钟后，浸泡在溶液中。此后，电导率稳定在0.0716 S/m和0.0224 S/m之间，具体取决于粘土类型和烧制温度。测量结果的再现性证明了冲洗程序的有效性。粘土提供可成形性，对离子是可渗透的，可以调节导电性值，因此适合于在幻影中的头骨建模。
Physical head phantoms allow the assessment of source reconstruction procedures in electroencephalography and electrical stimulation profiles during transcranial electric stimulation. Volume conduction in the head is strongly influenced by the skull, which represents the main conductivity barrier. Realistic modeling of its characteristics is thus important for phantom development. In the present study, we proposed plastic clay as a material for modeling the skull in phantoms. We analyzed five clay types varying in granularity and fractions of fire clay, each with firing temperatures from 550 degrees C to 950 degrees C. We investigated the conductivity of standardized clay samples when immersed in a 0.9% sodium chloride solution with time-resolved four-point impedance measurements. To test the reusability of the clay model, these measurements were repeated after cleaning the samples by rinsing in deionized water for 5 h. We found time-dependent impedance changes for approximately 5 min after immersion in the solution. Thereafter, the conductivities stabilized between 0.0716 S/m and 0.0224 S/m depending on clay type and firing temperatures. The reproducibility of the measurement results proved the effectiveness of the rinsing procedure. Clay provides formability, is permeable to ions, can be adjusted in conductivity value and is thus suitable for the skull modeling in phantoms.