【摘要】 我们根据微波照射生物组织时电磁场、热场、声波场三者之间的耦合关系,对微波激励热声成像正问题展开研究。从实验样本热学和声学的空间不均匀性角度出发,应用有限元方法求解热声波传播方程。由于入射微波对不同组织的穿透深度不同,不同组织对微波能量的吸收率不同,导致样本内部初始热声源的位置不同,相应地影响到声压传播情况。仿真结果表明,不同检测点声压信号中的信息量是不同的,检测点的声压信号富含样本中组织结构和电声学特性的信息量,从而能够从检测点的信号反映出关于样本结构和组成的信息。更多还原

【Abstract】 According to the coupling relationship of electromagnetic field,thermal field and acoustic field during the time that microwave irradiates the biological tissues,we conducted a study on the microwave-induced thermoacoustic tomography forward problem.In the study,we started from the thermoacoustic wave propagation that incorporated the spatial inhomogeneities of thermal and acoustic properties,and we used a method based on the finite element to solve the thermoacoustic equation.As the penetration depth and the specific absorption rate changed with the microwave frequency in biological tissue,the hotspot position and value altered,so the pressure wave propagation and the detecting value would be influenced.By analyzing the simulation results,we found that different detection point has different information content.Because the microwaveinduced acoustic waves contain abundant information about the structural,electromagnetic and acoustic properties of phantom,they can reflect information on the tissue composition and structure of the phantom effectively.更多还原