对临床上常用的2 450 MHz微波在均匀介质中的电透入深度进行了分析,基于生物组织的热波模型,研究了生物组织吸收微波能的热效应;实验采用红外热成像仪测温,以2 450 MHz的微波辐射器辐照均匀的分层仿生体模,根据实验数据对微波热疗中透热深度进行了研究,说明微波的透入深度和透热深度的区别,并给出微波辐射器的功率、辐照距离和辐照持续时间对透热深度的影响。结果表明:当采用增大功率、延长辐照时间和近距离辐照等手段,都可以提高微波在人体的透热深度,为体外微波热疗中的人体传输模型建立及热疗的无损测温与控温奠定实验基础。

According to the electromagnetic theory,permeating depth of the 2 450 MHz microwave in homogeneous media is analyzed.A nonlinear heat transfer model is applied to predict the temperature variation in biotissues under the microwave irradiation.Based on the thermal images measured by an far-infrared imager,the heat penetration of multi-layered homogeneous medium simulating biomaterial is studied.The experimental results show the difference between permeating depth and heat penetration.The heat penetration is mainly related to the power of microwave antenna,distance between antenna and biomaterial,and duration of irradiation,etc.Adopting high power microwave,long irradiation duration or close distance can enhance heat penetration in the human body.