DETECT HUMAN BEINGS BURIED UNDER EARTHQUAKE
USING EMBEDDED MICROCONTROLLER
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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 earthquake rubble or a construction barrier of about 10-ft thickness.
Existing methods for searching and rescuing human victims buried under earthquake rubble or collapsed building debris is the utilization of dogs, or seismic or optical devices. These existing devices are not effective if the rubble or debris covering the human victims is thicker than a few feet, especially for the case when the victims are completely trapped or too weak to respond to the signal sent by the rescuers.
PRINCIPLE OF OPERATION
The basic principle is that when a microwave beam of certain frequency [L (or) S band (or) UHF band] is aimed at a portion of rubble (or) collapsed building under which a person has been trapped, the microwave beam can penetrate through the rubble to reach the person. When the microwave beam focuses the person, the reflected wave from the person’s body will be modulated (or) changed by his/her movements, which include breathing and heartbeat. Simultaneously, reflected waves are also received from the collapsed structures.
The circuit description is as follows:
The microwave stable EM wave at 1150 MHz with an output power of 400mW (25.6 dBm). This wave is fed through a 10-dB directional coupler and a circulator before reaching a radio-frequency (RF) switch, which energized the dual antenna system sequentially. The 10-dB directional coupler branches out one-tenth of the wave (40 mW) which is then divided equally by a 3-dB directional coupler.
This paper have designed and constructed three types of antennas for the microwave life-detection system. They are:
1) The reflector antenna;
2) The patch antenna; and
3) The probe antenna.
A new sensitive life-detection system using microwave radiation for locating human subjects buried under earthquake rubble or hidden behind various barriers has been constructed. This system operating at 1150 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.