心脏模型中兴奋传播算法的改进

心脏电兴奋传播过程的仿真是心脏建模中的关键步骤。本文在二维空间中，心肌不分层和分层的情况下，讨论了心脏电兴奋传播的仿真处，根据惠更斯波动原理，计算出仿真时间的理论值，从而对目前最常用的LFX算法和矢量传播处的仿真时间误差进行分析。发现在心肌单元均匀时，LFX算法存在误差，而矢量传播算法没有误差，但是在心肌分层后兴奋传播途径不再是直线，矢量传播算法也带来误差，本文章对兴奋传播仿真算法提出了改进，与前两种算法比较误差显著减小，并分析了心肌划分精度对仿真算法误差的影响。

Improvement on Simulation Algorithm of Excitation Propagation in Heart Modeling

It is important to simulate the excitation propagation process of cardiac bio-electricity in the research of ECG forward problem. Traditional methods describe them with wave simulation algorithm such as LFX simulation algorithm and vector propagation algorithm etc, these methods have some problems to certain extent, due to the presence of discreteness of space and time and asymmetry of the myocardium. This paper discussed the simulation algorithm in 2-dimension space under the circumstance of layered and non-layered structure of myocardium. By calculating the theoretic values of simulating time based on Huygen's principle, we found that there were errors in LFX algorithm and no errors in vector propagation algorithm under the circumstance of non-layered structure of the myocardium, no mater what myocardium is isotropic or anisotropic. However, there exist errors from both algorithms when the myocardium has the layered structure. An improved algorithm is proposed and the simulations have been performed to examine the efficacy of the new algorithm, and the errors are reduced obviously. By increasing the number of myocardial blocks in the model, we also analyzed its influence on the error of simulation algorithm.