Abstract
This paper presents a monitoring system for detecting accidentally falling down in a nursing home using passive RFID tags. This system is installed in a lavatory, where the falling accidents happen the most frequently. The tag reader is set near a ceiling and the RFID tags are on the ground. The principle of this system is based on a phenomenon that electric waves are attenuated by water. The state of a person: standing or falling is judged from the number of the RFID tags that are not responded. This system is superior to the video camera as to privacy. Experimental results confirm the effectiveness of this system.
