title: A Method for Remotely Sensing Vital Signs of Human Subjects Outdoors.
abstract: After chemical or nuclear leakage or explosions, finding survivors is a huge challenge. Although human bodies can be found by smart vehicles and drones equipped with cameras, it is difficult to verify if the person is alive or dead this way. This paper describes a continuous wave radar sensor for remotely sensing the vital signs of human subjects. Firstly, a compact and portable 24 GHz Doppler radar system is designed to conduct non-contact detection of respiration signal. Secondly, in order to improve the quality of the respiration signals, the self-correlation and adaptive line enhancer (ALE) methods are proposed to minimize the interferences of any moving objects around the human subject. Finally, the detection capabilities of the radar system and the signal processing method are verified through experiments which show that human respiration signals can be extracted when the subject is 7 m away outdoors. The method provided in this paper will be a promising way to search for human subjects outdoors.
authors.affiliation: Department of Biomedical Engineering, Fourth Military Medical University, Xi'an 710032, China. lichuantao614@126.com.
authors.forename: Chuantao
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, Fourth Military Medical University, Xi'an 710032, China. cfm5762@126.com.
authors.forename: Fuming
authors.initials: F
authors.lastname: Chen
authors.affiliation: Department of Biomedical Engineering, Fourth Military Medical University, Xi'an 710032, China. fmmujxj@fmmu.edu.cn.
authors.forename: Jingxi
authors.initials: J
authors.lastname: Jin
authors.affiliation: Department of Biomedical Engineering, Fourth Military Medical University, Xi'an 710032, China. lvhao@126.com.
authors.forename: Hao
authors.initials: H
authors.lastname: Lv
authors.affiliation: Department of Biomedical Engineering, Fourth Military Medical University, Xi'an 710032, China. sheng@mail.xjtu.edu.cn.
authors.forename: Sheng
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, Fourth Military Medical University, Xi'an 710032, China. lugh1976@fmmu.edu.cn.
authors.forename: Guohua
authors.initials: G
authors.lastname: Lu
authors.affiliation: Department of Biomedical Engineering, Fourth Military Medical University, Xi'an 710032, China. jianqiwangjmk@126.com.|Shaanxi University of Technology, Hanzhong 723001, China. jianqiwangjmk@126.com.
authors.forename: Jianqi
authors.initials: J
authors.lastname: Wang
mesh_terms: D000465:Algorithms; D004630:Emergencies; D006801:Humans; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000379:methods*; D011825:Radar; D012119:Respiration; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D017741:Survivors
keywords: 24 GHz Doppler radar; moving  object interference; respiration; searching for survivors