基于声学不均匀特性的磁感应磁声成像声压解析

目的 依据人体声学参数,探索磁声耦合成像声信号在声学非均匀媒介中的传播对检测结果的影响.方法 参考人体组织声学特性建立仿真模型,借助有限元分析工具进行电磁场仿真,采用时域有限差分方法求解磁声信号在仿真模型中的传播,并在自由空间采集声压信号.最后,对比研究磁声信号在声学均匀模型和声学非均匀模型中的传播过程.结果 在两个声学模型中声源分布相同,声学非均匀模型中采集的声压信号峰值数量多于声源边界,且声压峰值间的时间间隔与声源边界之间的距离不匹配.结论 初步揭示了声学非均匀特性对磁感应磁声成像的影响,为声学非均匀媒介的重建算法研究奠定了一定基础.

An analytical method of acoustic pressure for magnetoacoustic tomography with magnetic induction based on acoustic inhomogeneity

Objective According to the acoustic parameters of human body,we explore the influence of the propagation of sound signal in inhomogeneous media at magnetic acoustic coupling imaging.Methods We build a simulation model with the reference of acoustic properties in human tissues.And electromagnetic simulation is made by using finite element analysis tools.Then,magnetic acoustic signal propagation is solved in simulation models with the FDTD method and sound pressure signals are collected in free space.Finally,we compare the acoustic signal propagation in acoustic homogeneous model and acoustic inhomogeneous model.Results The two acoustic models have the same distribution of acoustic source.However,the number of peaks in the collected signal for acoustic inhomogeneous model is larger than that of acoustic source boundaries,and the time interval between the peaks of acoustic pressure does not match the distance between the acoustic source boundaries.Conclusions This paper reveals the impact of acoustic inhomogeneity on magnetoacoustic tomography with magnetic induction,and lays a foundation for the study of reconstruction algorithm at acoustic inhomogeneous media.