中文摘要：

为克服电阻抗成像（electrical impedance tomography，EIT）信息量少，正、逆问题计算时由于实际三维场近似到二维时引入误差等弊端，在开放式EIT基础上改进一维电极阵列为二维电极阵列，拓展求解域到整个三维场，以增加信息量，消除模型误差。针对目前EIT的几种激励模式，运用有限元法求解不同模式下的正问题，以区分度和表面投影成像的方法评估各种激励模式对三维场域内扰动的敏感度。结果表明背电极方式在探测深度、精度上具有明显优势，临床应用简便，可为下一步三维EIT的研究提供参考。

英文摘要：

To solve the lack of information and the error in forward and inverse problem caused by the ~pproximation of actual three-dimensional field from two-dimensional field in electrical impedance tomography （EIT）, this article presents a new EIT system. This system improves one-dimensional electrode array to two-dimensional array, and extends the solution domain to the entire three-dimensional field in order to increase the information quantity and eliminate the model error. Based on several current stimulation patterns in EIT which might yield the best sensitiveness for 3-D field, we calculate the forward problem by finite element method and the distinguishability and surface projection image method. The results show that the back electrode pattern has obvious advantages in detecting depth and precision, and has convenience in clinical application. The conclusion of this article can provide reference for the study of 3-D EIT.