MDEIT中电流密度成像替代电导率成像的可行性分析

针对新型磁探测电阻抗成像技术的正问题,利用有限元方法求解得到目标体内部的电压和电流密度分布,然后根据Biot-Savart定律获得目标体外部的磁感应强度数据,并且分析了有限元方法计算正问题的精度.结果表明,其足以用于磁探测电阻抗成像的电导率图像重建.在此基础上,通过仿真实验发现环形电极模式避免了电流的扩散效应,远离电极部分的z方向电流密度图像与电导率图像一致,以电流密度成像替代电导率成像,使得磁探测电阻抗成像简化为磁探测电流密度成像,缩短了数据测量时间和图像重建时间,为快速成像奠定了基础.

Feasibility Analysis on Current Density Imaging in Place of Conductivity Imaging for MDEIT

With regard to the forward problem of magnetic detection electrical impedance tomography （MDEIT）, voltage and current density distributions inside the object were computed using the finite element method（FEM）. Then, the magnetic flux density around the object was calculated using the Biot-Savart law. The performance of the forward solver was analyzed. Results show that it meets the demand of conductivity image reconstruction in MDEIT. Based on the forward solver, the simulation experiments＇ results indicate that the toroidal electrodes can avoid the current spreading effect near electrodes. Consequently, the z direction current density image is the same as the con- ductivity image for the section far away from the electrodes. The conductivity imaging is replaced with current density imaging and the MDEIT is simplified to magnetic detection current density imaging （MDCDI）, which shortens the data measurement time and image reconstruction time. This method can provide a new way for the rapid imaging.