非均匀电磁介质中的等效源重构

摘要

In this paper, a method that uses magnetic extreme signals for equivalent source reconstruction is presented. Through simulation of specific current dipoles given as the sources of magnetic field signals, the feasibility of a multi-chamber heart model is investigated and the accuracy analysis of equivalent source reconstruction in inhomogeneous media is conducted. The magnitude of the magnetic extreme signals is indicative of the influence of volume conductor on the cardiac magnetic field is analyzed. The method is compared with other four methods which are the method of magnetic gradient extreme signals, the Nelder-Mead algorithm, the trust region reflective algorithm, and the particle swarm optimization algorithm against the criteria in terms of accuracy of source reconstruction and computation time of the algorithm. Results show that the method is practically useful for solving inverse cardiac magnetic field problems.%本文提出了一种用于等效源重构的磁场极值信号法。并通过给定不同的电流偶极子作为信号源，仿真研究了多腔体心脏磁场模型及非均匀介质情况下等效源重构的精度。分析了体电导对心脏磁场的影响，以及磁场极值信号反映的体电导作用。文中将该方法与其他四种源估计方法：磁场梯度极值法、Nelder-Mead单纯形算法、信赖域反射算法和粒子群优化算法作了比较。分析了这些方法的源重构精度和计算所需时间。结果表明，这种针对非均匀介质情况提出的心脏磁场逆问题求解方法有一定的实用价值。