| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a clock letting a user know comfortable waking time by detecting the time when the user falls asleep or starts his first REM sleep to sound an alarm every sleeping cycle of 90 minutes, based on the fact that the human sleep has a cycle of 90 minutes for REM sleep and non-REM sleep combined, which means that one can wake up refreshed if awakened after one and a half hours, three hours, four and a half hours, six hours, seven and a half hours, and so on, of sleep. SOLUTION: Pulse rate drops gradually after one falls asleep, and after reaching a minimal value, it rises greatly (about 10%) at the beginning of first REM sleep. This change is detected and signaled to a wristwatch or a clock having an alarm device to switch on an alarm that sounds every 90 minutes. Changes in pulse rate are detected by a photosensor attached to a fingertip and a built-in computing circuit is used for such a control as switching the alarm on.</p> |
