Through-Floor Vital Sign Imaging for Trapped Persons Based on Optimized 2-D UWB Life-Detection Radar Deployment

This letter presents a novel image-based vital sign detection strategy for trapped persons based on the optimized two-dimensional (2-D) ultrawideband (UWB) radar deployment. The main novelty is that the slow-time images based on 2-D radar deployment are created to continuously screen the trapped persons with periodic micromotions in a specific area. According to the optimized deployment, multiple UWB life-detection monostatic radars are distributed and work in a time-division-multiplexing mode. These radars are sequentially controlled and activated to capture information from all possible wave incidents and scattering angles. The 2-D radar deployment is designed and optimized using the multiple-input and multiple-output (MIMO) array topology technique. The vital sign is modeled as the slow-time image, and multiple images might contain the periodic weak responses from the trapped persons. Proof-of-principle experiments were carried out based on an optimized 2-D UWB radar deployment. All observation points in this deployment are sequentially selected to complete the transmission and reception of the UWB monostatic radar. Finally, the experimental results validate the effectiveness of the proposed image-based vital sign strategy on the azimuth locations of the trapped persons.