融合边界条件的电阻抗图像重建仿真研究

结合成像目标的边界结构信息，提出一种新的改善电阻抗图像重建质量的方法．在生物医学电阻抗断层成像中，将传统采用圆形场域的重建模型改进为与人体胸腔边界近似的八边形场域，建立正问题数学模型，求解得到灵敏度系数矩阵，经等位线滤波反投影算法获得感兴趣区域的仿真分布图像．针对成像目标在场域中的不同分布情况，采用面积占空比对两种重建模型下的成像效果进行评价．图像及数据分析结果表明，改进方法重建图像伪影明显减少，面积占空比也更接近真实分布，提高了图像空间分辨率，达到了改善电阻抗重建图像质量的目的．

Simulation Study of the Electrical Impedance Tomography Fused the Boundary Conditions

To improve the quality of the electrical impedance reconstructed image, an improved method that fused the boundary structure information to refine the reconstructed image was proposed. In biomedical impedance tomography, the conventional circular field was changed into the octagon field that approximate for the human chest, a mathematical model for solving the forward problem was established, and the sensitivity coefficient matrix was renewed, then used the equi- potential filtered back projection algorithm to realize the image reconstruction of the simulated distribution within the inter- esting region, the comparative effect was evaluated by the area ratio when the objects exist at different positions. The simulation results indicate that artifacts of the reconstructed images reduce significantly, and the ratio area is also closer to the real distribution, the spatial resolution is improved obviously, achieve the purpose of improving the quality of the electrical impedance tomography.