胃区3层EIT模型构建和仿真  

Construction and Simulation of Three-Layer EIT Model in Gastric

作　　者：李章勇[1] 刘兆宇[1] 冉鹏[1] 相尚志 马成群[1] 王伟[1] Li Zhangyong;Liu Zhaoyu;Ran Peng;Xiang Shangzhi;Ma Chengqun;Wang Wei(Biomedical Engineering Research Center,Chongqing University of Posts and Telecommunication,Chongqing 400065,China)

机构地区：[1]重庆邮电大学生物医学工程研究中心

出　　处：《中国生物医学工程学报》2019年第5期590-598,共9页Chinese Journal of Biomedical Engineering

基　　金：国家自然科学基金(61571070,61601072)

摘　　要：构建3层电阻抗成像技术(EIT)模型,研究不同电极激励模型下胃排空信息的规律,以及胃内容物电导率不同时胃阻抗测量信号的变化情况。利用COMSOL MULTIPHYSICS仿真软件,以人体解剖学为基础,构建包含胃、肝胆的人体腹腔模型,并在模型外构建3层电极模型,每层16个电极,以5 mA的安全电流为激励源进行仿真。分别设定相对和相邻电极激励模型,设定不同的胃内容物,即绝缘试餐0.054 S/m、导电试餐1 S/m和中性试餐0.5 S/m等3种条件,用以模拟不同食物在胃内的情况;设定胃体积由2倍变为1倍的过程,模拟胃排空过程,进行仿真实验研究。包括对测量电压进行数据分析,利用评价参数边界测量电压敏感性δ,利用边界电压测量动态范围U对测量电压进行稳定性和检测效果的评价。相对电极模型的测量电压敏感性δ较高,且其在绝缘试餐时较导电试餐时小;而相邻模型的δ在绝缘试餐时较导电试餐时大,边界测量动态范围U也相对更大。对测量的敏感性而言,在试餐电导率0.054 S/m时,两种激励模式分别为34.13与34.25;试餐电导率1 S/m时,两种激励模式分别为33.60与26.68。3层EIT模型可提供达24×23×3组水平测量数据组,以及根据测试需求的可扩展交叉激励数据组,能够得到更多的胃排空信息,有效地反映胃内容物情况,以及胃排空过程的信息关系。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 range U 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 inf

关 键 词：电阻抗成像技术 胃排空 胃内容物 仿真实验 

分 类 号：R318[医药卫生—生物医学工程]