基于微波聚焦天线的肺部感染检测OA

Based on the derivation of the magnetic field distribution generated by a planar field source within multi-layered human tissue,1.5 GHz was chosen to be the operating frequency for microwave-based pulmonary infection detection.Then the time reversal(TR)method was used to obtain the predetermined phase of the array antenna to facilitate the microwave focusing on the measured target,whereas the prediction model was obtained by using the least square estimation based on the simulation data.Preliminary verification showed that the resolution of the infected region is as high as 14 mm at the subcutaneous depth of 80 mm.The resonant frequency,the relative bandwidth and the voltage standing wave ratio of the antenna prototype were measured to be 1.49 GHz,14.67%,and 1.03,respectively.Moreover,an ex vivo experiment was carried out by using pork and lung-mimicking gel,whereas the result showed that the array antenna excited by the TR-based phases produced a focused field at the target location.Furthermore,a 20 mm diameter pellet filled with deionized water was used to simulate an infected region,which was determined by the prediction model to be 25.11 mm in diameter with an error of 25.55%.These results can provide theoretical foundation and design guidelines for the application of the microwave focusing method in the rapid detection of pulmonary infections.