Chen K M, Huang Y, Zhang J, Norman A
Department of Electrical and Computer Engineering, Michigan State University, East Lansing 488241, USA.
IEEE Trans Biomed Eng. 2000 Jan;47(1):105-14. doi: 10.1109/10.817625.
A new sensitive microwave life-detection system which can be used to locate human subjects buried under earthquake rubble or hidden behind various barriers has been constructed. This system operating at 1150 MHz or 450 MHz can detect the breathing and heartbeat signals of human subjects through an earthquake rubble or a construction barrier of about 10-ft thickness. The basic physical principle for the operation of a microwave life-detection system is rather simple. When a microwave beam of appropriate frequency (L or S band) is aimed at a pile of earthquake rubble covering a human subject or illuminated through a barrier obstructing a human subject, the microwave beam can penetrate the rubble or the barrier to reach the human subject. When the human subject is illuminated by a microwave beam, the reflected wave from the human subject will be modulated by the subject's body movements, which include the breathing and the heartbeat. If the clutter consisting of the reflected wave from stationary background can be completely eliminated and the reflected wave from the human subject's body is properly modulated, the breathing and heartbeat signals of the subject can be extracted. Thus, a human subject buried under earthquake rubble or hidden behind barriers can be located. This system has been tested extensively in a simulated earthquake rubble in the laboratory and also in a field test using realistic earthquake rubble conducted by a Federal Emergency Management Agency (FEMA) Task Force.
一种新型的灵敏微波生命探测系统已被构建出来，该系统可用于定位埋在地震废墟下或隐藏在各种障碍物后的人体。这个工作在1150兆赫或450兆赫的系统，能够透过约10英尺厚的地震废墟或建筑障碍物检测到人体的呼吸和心跳信号。微波生命探测系统运行的基本物理原理相当简单。当一束适当频率（L波段或S波段）的微波束对准覆盖着人体的一堆地震废墟，或者透过阻挡人体的障碍物进行照射时，微波束能够穿透废墟或障碍物到达人体。当人体被微波束照射时，来自人体的反射波会被人体的身体运动调制，这些运动包括呼吸和心跳。如果能够完全消除由静止背景反射波构成的杂波，并且对来自人体的反射波进行适当调制，就可以提取出人体的呼吸和心跳信号。这样，就能够定位埋在地震废墟下或隐藏在障碍物后的人体。该系统已经在实验室的模拟地震废墟中进行了广泛测试，还在联邦紧急事务管理局（FEMA）特遣部队进行的使用真实地震废墟的现场测试中进行了测试。
