Study on Microwave Thorax Imaging for Human Respiration Monitoring

A microwave thorax imaging system is designed for human respiration monitoring. A compact low-profile symmetrical dipole antenna is designed as sensing antenna. A 16-antenna array is fabricated and mounted on a wearable belt. The antenna array is controlled by a switch matrix and the data acquisition is completed with a vector network analyzer. During the measurement, each antenna acts as a transmitter alternately and the other antennas act as the receivers. Human respiration experiments are conducted and S-parameters are measured continuously during respiration. The Jacobian Weighted One-step Supervised Descent Method (SDM) is applied to the reconstruction of both synthetic and measured data. The distribution of dielectric properties in human thorax is reconstructed and the results verify the feasibility of monitoring human respiration with microwave.