边界元法在求解基于三维非均匀人体胸腔模型的心电图正问题中的应用

Solutions of Forward Problem of ECG by Means of BEM in an Inhomogeneous Human Thoracic Model

在给出三维人体胸腔仿真模型的基础上 ,提出了如何用边界元法实现包含非均匀介质的人体场域的求解 ,先建立每个介质均匀区域中的边界积分方程 ,再通过内部共有边界上的电位连续和电流密度的法向分量连续建立总方程组 ,然后代入外部边界条件加以求解。文中给出了用该方法求解均匀场域和直接求解均匀场域生成的仿真结果———体表电位分布图 ,结果表明两者的分布情况几乎吻合 ,只是幅值稍有改变 (相对误差不超过± 4 % ) ,这说明用此方法求解包含非均匀介质的人体场域是可行的 ,并可以得到较理想的结果。

Based on a simulative 3 D human thoracic model,a method how to solve the human field including mediums by means of boundary element method (BEM) was advanced.Firstly,building the boundary integral equations in every homogeneous field respectively;then combining these equations together as the total one according to internal boundary conditions on the interfaces;finally,solving this problem by adding the external boundary conditions.Two body surface potential maps(BSPMs),which one was produced in homogeneous field by using the method above,another was computed in homogeneous field directly were given.The results showed that there were almost no differences between them,but the amplitude changed slightly(relative errors≤±4%).Thus it can be seen that is feasible to solve inhomogeneous human field in terms of the method.