基于声换能器特性的三维磁感应磁声成像重建算法

A 3D MAT-MI Reconstruction Algorithm Based on Characteristics of Acoustic Transducer

为了完善磁感应磁声成像算法,使其在真实声检测系统下都适用,研究声换能器特性对磁感应磁声成像重建效果的影响。依据换能器声场分布测量数据,采用插值方法建立真实声换能器三维声场分布模型,利用格林函数法及离散化方法建立磁感应磁声成像正逆问题算法。为了验证该算法,分别采用球扫描和柱扫描方式进行仿真。基于S-L CT仿真模型建立三维仿体电导率模型,用有限元方法对瞬态电磁场进行分析,根据计算的涡流分布结果,使用Matlab进行数值计算。仿真结果表明:该算法可基本重建出原始力源的分布,重建图像的相关系数分别达到98.49%和94.96%,对一般声换能器比较适用。该研究为进一步的实验研究和实验重建的精确性提供理论依据。

Aim to apply MAT-MI reconstruction algorithm to general sound detection systems, the influence of acoustic transducers on MAT-MI image reconstruction were investigated in this paper. The acoustic intensity measurement system was used to measure the acoustics.field, and then the data was used to build the acoustic transducer model by a interpolation method. The model was applied to forward and inverse problems of MAT-MI based on Green＇ s function and discretization method. In order to verify the algorithm, a simulation was carried out using sphere scan schema and cylinder scan schema. A 3D phantom model was set up based on S-L model in CT, with the help of finite element analysis method and the distribution of the transient electromagnetic field and the eddy current were calculated. Simulation and reconstruction results through numerical calculation using Matlab were obtained. Results show that the algorithm can reconstruct the distribution of acoustic source vector; the correlation coefficients are 98.49% and 94.96% , which can be applied to the general transducer. This study provided a basis for the experimental study of MAT-MI and a precise reconstruction of conductivity distribution.