| 摘要 |
<p>Body motions of a sleeper are detected in non-contact with the sleeper by a piezo-electric element (13), and, whenever a detection output exceeds a preset value, time measurement by a timer is reset and a new time measurement is started. When a measured time by the timer exceeds a preset time, it is determined that the sleeper has fallen asleep on the bedding. Further, slight body motions conveyed by the activity of the heart and breathing motions of the human body are detected to determine the absence on the bedding, presence on the bedding or rough body motions. When the presence is determined, the time measurement action is started by the timer, and, when the absence or rough body motion is determined, the time measurement is reset. When the measured time of the timer exceeds the preset time, it is determined that the sleeper has fallen asleep on the bedding.</p> |
