Abstract：The aim of this work is to establish a three-layer electrical impedance tomography (EIT) model to study the regularity of gastric emptying under different electrode models and the change of gastric impedance measurement signals when the electrical conductivity of gastric contents is different. In this paper, COMSOL MULTIPHYSICS simulation software was used to build a human abdominal model and a three-layer electrode model with 16 electrodes on each layer. The excitation was simulated by a 5 mA excitation current, and the relative and adjacent electrode model was set. The simulation experiments were carried out under the condition of insulation test meal of 0.054 S/m, conductive test meal of 1 S/m and neutral test meal of 0.5 S/m, and the stomach volume changed from 2 times to 1 time. Simulations were performed according to the pattern of relative excitation and adjacent excitation. The data of the measurement voltage were analyzed, and the voltage sensitivity δ and the boundary voltage measurement dynamic rangeU~ were used to evaluate the stability of the measurement voltage and the detection effect. The larger the value of δ, the better the system detection effect was. The relative electrode model had higher measurement voltage sensitivity δ, and it was smaller than that of the conductive test meal during the insulation test. The voltage sensitivity δ of the adjacent model was larger than that of the conductive test meal during the insulation test, and the dynamic range of the boundary measurement is also relatively larger. When the conductivity was 0.054 S/m, the results of two incentive modes were 34.13 and 34.25, respectively; when the conductivity was 1 S/m, the two incentive modes were 33.60 and 26.68, respectively. The three-layer EIT model could provide 24×23×3 groups of horizontal measurement data sets, as well as the scalable cross-stimulation data sets according to the requirements, providing more information about gastric emptying and effectively reflecting the situation of gastric contents and the information relationship of gastric emptying process.
李章勇, 刘兆宇, 冉鹏, 相尚志, 马成群, 王伟. 胃区3层EIT模型构建和仿真[J]. 中国生物医学工程学报, 2019, 38(5): 590-598.
Li Zhangyong, Liu Zhaoyu, Ran Peng, Xiang Shangzhi, Ma Chengqun, Wang Wei. Construction and Simulation of Three-Layer EIT Model in Gastric. Chinese Journal of Biomedical Engineering, 2019, 38(5): 590-598.
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