基于场量提取法的电磁层析成像系统的灵敏度推算

摘要

Electromagnetic tomography(EMT) is a relatively new modality in electrical tomography technology,which reconstructs the conductivity and permeability distribution of region of interest by detecting the mutual inductance between exciting and receiving coils. The calculation of sensitivity matrix is the key part of Electromagnetic tomography,and is essential for image reconstruction. The accuracy of the sensitivity maps will affect the image quality.EMT sensitivity maps were calculated by a method that utilizes the extracted field values. The mathematical expression of EMT sensitivity was derived theoretically. Computationally, the conductivity and permeability sensitivity were calculated respectively for the first time,with their maps diaplayed in MATLAB,which provide favorable conditions for accurate image reconstruction algorithm.%电磁层析成像技术(EMT)是一种新型的电学层析成像技术,它通过测量激励和接受线圈之间的互感变化而实现物场区域内电导率和磁导率分布的图像重建.灵敏度的计算是电磁层析成像技术的关键环节,是图像重建的必备条件,灵敏度计算的准确性直接影响到最终的成像精度.采用场量提取的方法计算了EMT系统的灵敏度.理论上,首次完整地推导出了EMT灵敏度的数学表达式.仿真计算上,借助MATLAB软件分别实现了电导率和磁导率灵敏度的独立计算,并依次绘制了相应的灵敏度图,为精确图像重建算法提供了有利条件.