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.
[1] Dughera L, Navino M, Cassolino P, et al. The diagnosis of gastroesophageal reflux disease[J]. Minerva Gastroenterol Dietol, 2007, 53(2):143-152. [2] Maia B M, Martí L, Mínguez M. [Diagnostic and therapeutic approach to patients with gastroparesis].[J]. Gastroenterol Hepatol, 2007, 30(6):351-359. [3] Liu R, Jin C, Song F, et al. Nanoparticle-enhanced electrical impedance detection and its potential significance in image tomography.[J]. International Journal of Nanomedicine, 2013, 8(1):33-38. [4] 王磊, 赵舒, 田云杰,等. 电阻抗成像胃动力功能检测的初步研究[J]. 医疗卫生装备, 2016, 37(5):1-4. [5] 苌飞霸, 张和华, 尹军. 生物电阻抗测量技术研究与应用[J]. 中国医学物理学杂志, 2015, 32(2):234-238. [6] 任超世, 李章勇, 赵舒. 生物电阻抗胃动力检测与评价[J]. 世界华人消化杂志, 2010, 18(1):1-8. [7] Podczeck F, Mitchell CL, Newton JM, et al. The gastric emptying of food as measured by gamma-scintigraphy and electrical impedance tomography (EIT) and its influence on the gastric emptying of tablets of different dimensions[J]. J Pharm Pharmacol, 2007, 59(11):1527-1536. [8] Soulsby CT, Khela M, Yazaki E, et al. Measurements of gastric emptying during continuous nasogastric infusion of liquid feed: Electric impedance tomography versus gamma scintigraphy [J]. Clin Nutr, 2006, 25(4):671-680. [9] Djajaputra D. Electrical impedance tomography: Methods, history and applications[J]. Medical Physics, 2005, 32(8):2731-2731. [10] Mcclelland GR, Sutton JA. Epigastric impedance: A non-invasive method for the assessment of gastric emptying and motility[J]. Gut, 1985, 26(6):607-614. [11] Giouvanoudi AC, Spyrou NM. Epigastric electrical impedance for the quantitative determination of the gastric acidity[J]. Physiological Measurement, 2008, 29(11):1305-1317. [12] Huertafranco R, Vargasluna M, Hernandez E, et al. Use of short-term bio-impedance for gastric motility assessment[J]. Medical Engineering & Physics, 2009, 31(7):770-774. [13] Li Zhangyong, Ren Chaoshi. Gastric motility measurement and evaluation of functional dyspepsia by a bio-impedance method[J]. Physiological Measurement, 2008, 29(6): S373-S382. [14] Li Zhangyong, Ren Chaoshi, Zhao Shu, et al. Gastric motility functional study based on electrical bioimpedance measurements and simultaneous electrogastrography[J]. 生物医学与生物技术, 2011, 12(12):983-989. [15] 徐管鑫, 王平, 何为. 实时电阻抗成像系统及实验研究[J]. 仪器仪表学报,2005,26(9):886-890. [16] 任超世, 李章勇, 王妍, 等. 电阻抗断层成像应用基础与临床应用的一些研究进展[J]. 中国生物医学工程学报, 2010, 29(2):300-304. [17] Chen Xiaoyan, Wang Huanxiang, Shi Xiaolei, et al. Comparisons between circle and structural models in lung ventilation reconstruction by electrical impedance tomography[C]// International Conference on BioMedical Engineering and Informatics. Washington, DC: IEEE Computer Society, 2008,2:53-57. [18] 姜均本. 人体断面解剖学彩色图谱与CT、MRI应用[M]. 北京:科学出版社, 1997. [19] Woo EJ, Hua P, Webster JG, et al. Measuring lung resistivity using electrical impedance tomography[J]. IEEE Transactions on Biomedical Engineering, 1992, 39(7):756-760. [20] Avill R, Mangnall YF, Bird NC, et al. Applied potential tomography. A new noninvasive technique for measuring gastric emptying[J]. Gastroenterology, 1987, 92(4):1019-1026. [21] 范文茹. 生物电阻抗成像技术研究[D]. 天津:天津大学, 2010.
