Guidetti Matteo, Ferrara Rosanna, Montemagno Kora, Maiorana Natale Vincenzo, Bocci Tommaso, Marceglia Sara, Oliveri Serena, Bianchi Anna Maria, Priori Alberto
'Aldo Ravelli' Research Center for Neurotechnology and Experimental Neurotherapeutics, Department of Health Sciences, University of Milan, 20142 Milan, Italy.
Department of Electronics, Information and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy.
Bioengineering (Basel). 2025 Mar 27;12(4):346. doi: 10.3390/bioengineering12040346.
Transcranial direct current stimulation (tDCS)-induced electric fields (EFs) acting on brain tissues are hardly controllable. Among physical models used in neuroscience research, watermelons are known as head-like phantoms for their dielectric properties. In this study, we aimed to define an inexpensive and reliable method to qualitatively define the spatial distribution of tDCS-induced EFs based on the use of watermelons.
After creating the eight cranial foramina and identifying the location of the 21 EEG scalp electrodes on the peel of a watermelon, voltage differences during stimulation were recorded in each of the 21 scalp electrode positions, one at a time, at four different depths. The recordings were graphically represented by using polar coordinates with the watermelon approximated to a perfect sphere.
To validate the model, we performed three experiments in well-known montages. The results obtained were in line with the expected behavior of the EFs.
Watermelon might be a cheap and feasible phantom head model to characterize the EFs induced by tDCS and, potentially, even other non-invasive brain stimulation techniques.
经颅直流电刺激（tDCS）产生的作用于脑组织的电场（EFs）难以控制。在神经科学研究中使用的物理模型中，西瓜因其介电特性而被视为类似头部的模型。在本研究中，我们旨在基于西瓜定义一种廉价且可靠的方法，以定性地确定tDCS诱导电场的空间分布。
在西瓜皮上制作八个颅孔并确定21个脑电图头皮电极的位置后，在四个不同深度，每次在21个头皮电极位置中的一个位置记录刺激期间的电压差。通过将西瓜近似为完美球体，使用极坐标对记录进行图形表示。
为验证该模型，我们在知名组合中进行了三项实验。获得的结果与电场的预期行为一致。
西瓜可能是一种廉价且可行的模拟头部模型，可用于表征tDCS诱导的电场，甚至可能用于表征其他非侵入性脑刺激技术诱导的电场。
