面向脑肿瘤检测的高精度电磁正反演算法研究

For brain tumors, early diagnosis is particularly important. Thus, detection technology with high accuracy is required. Because of the high resolution of the UWB microwave signal, small tumors can be detected. Moreover, UWB microwave signal injury small on the human body, and the detection equipment is low cost. So the UWB microwave signal is very suitable to be used as a signal source for brain tumor detection. In the theoretical analysis, with the advantage of the UWB microwave signal, this topic plans to build an electromagnetic simulation model of brain tissue used the forward electromagnetic simulation algorithm. Then, the location and size of brain tumors are calculated with some inverse scattering imaging algorithm. Finally, the results are compared with the preset position and size to prove the correctness of the forward and inversion algorithm. Also, the forward and inversion algorithms are optimized to improve the detection accuracy, and to provide theoretical guidance for physical prototype production. But at present, the accuracy of the forward and backward algorithms is not enough. Thus, by computer conformal modeling, this project plans to use the UWB microwave signal as the signal source, based on the real 3D brain anatomical model, to build a virtual and real 3D electromagnetic model of brain tissue by the forward ICCG-SFDTD algorithm and the inversion DAS imaging algorithm for research on brain tumor detection. This model has the advantages of high precision, fast computing speed and reality.

对于脑肿瘤，早期诊断非常重要，需要高精度的检测技术。UWB微波信号的分辨率高，可检测出体积很小的肿瘤，且对人体伤害小，制成的设备成本低，非常适合作为脑肿瘤检测的信号源。在理论分析研究中，可利用UWB微波信号的优势，先采用正演的电磁仿真算法，构建脑组织的电磁仿真模型，再采用逆散射成像算法，反演计算出脑肿瘤的位置和大小，和预先设置的位置和大小对比，验证正反演算法的正确性，并对算法进行优化，提高检测精度，为实物样机的制作提供理论指导。但是目前国内外研究的正反演算法精度不足，因此本项目拟采用UWB微波信号作为信号源，基于真实的三维脑组织解剖学模型，用阻抗分析仪实测出脑组织各结构电磁参数值，采用正演的ICCG-SFDTD算法和反演的DAS成像算法，通过计算机共形建模，构建一个虚拟真实的，有脑肿瘤的三维脑组织电磁正反演计算模型，用于脑肿瘤检测研究。该模型具有计算精度高，运算速度快，贴近实际的优点。

对于脑肿瘤，早期诊断和治疗尤为重要，需要高精度的检测技术。UWB微波信号的分辨率高，可检测出体积很小的肿瘤，且对人体伤害小，制成的设备成本低，非常适合作为脑肿瘤检测的信号源。. 本项目通过计算机建模，采用UWB微波信号为信号源，构建一个虚拟的、真实的，有脑肿瘤的脑组织电磁正反演计算模型，基于正演的电磁仿真算法，即SFDTD辛时域有限差分电磁算法，和反演的逆散射成像算法，即BF波束成形成像算法，将反演计算出的脑肿瘤位置和大小，和预先设置的位置和大小对比，验证正反演算法的正确性。并对算法进行优化，最终能够获得最佳的脑肿瘤成像结果。. 同时，本项目将相关算法应用于便携式脑肿瘤微波检测装置研究上，对检测装置中的UWB微波信号产生系统、UWB微波信号采集处理系统、UWB天线阵列、成像算法单元、电源模块和交互模块的设计进行较为具体的阐述和探讨。