| 摘要 |
PROBLEM TO BE SOLVED: To provide an abnormality detector which can simply detect whether human being moves or not even if it is place that has heat source such as bathroom or dark environment, and which is inexpensive. SOLUTION: The abnormality detector 1 is installed on the wall surface of a bathroom, and detects abnormal situation such as bathing person's cardiac halt. The abnormality detector 1 comprises a processing circuit part 2, a loudspeaker 3, and a microphone 4. Measurement sound emitted from the loudspeaker 3 reflects at the wall surface and the ceiling of the bathroom, bathing person 60 etc. The reflected measurement sound is collected together with direct sound by the microphone 4. Signal processing is performed at the processing circuit part 2. The processing circuit part 2 calculates sound transfer function in the bathroom between the loudspeaker 3 and microphone 4. By watching temporal change of the sound transfer function, it is decided that the bathing person stands still or moves, and as the result abnormality is detected. COPYRIGHT: (C)2005,JPO&NCIPI
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