(RxWiki News) Most people know the feeling; when the alarm clock goes off in the morning, you somehow feel tired even though you went to bed at a reasonable hour and feel like you got enough sleep.
But the stage of sleep that when are in when we are forcibly awakened has a lot to do with how refreshed we feel in the morning.
Humans spend about one-third of their lives asleep, and it's a vital function for growth and rejuvenation of all biological systems. Sufficient sleep is also necessary for normal motor and cognitive functions.
Waking naturally is optimum for uninterrupted sleep cycles, but for many people the use of an alarm clock is necessary - which is where the problems come in.
"Sleep management is important, buy an alarm clock."
Researchers in India think they've found the answer. They have detailed a scientifically-based alarm clock that would actually monitor brain activity and trigger its alarm during a time window that you've set in advance - but only at the point when your brain is in a lighter-sleep state and more easily roused, rather than in a deep sleep stage.
Lead author Jemina Asnoth Sylvia of Jerusalem College of Engineering says that such an alarm clock will allow the user to wake up feeling much more refreshed than with a traditional alarm clock, that would go off no matter the level of sleep stage at the time.
Sylvia and her team point out that sleep usually involves 90-minute cycles of brain activity; during each cycle, there are periods when the brain is more arousal. Being woken during those times will make a person feel more refreshed than being woken during the deeper part of the sleep cycle.
The brain-monitoring alarm clock would require putting EEG scalp electrodes on the head during sleep, which would hook up to a modified alarm clock. Beyond the experimental stage, the researchers propose a headband worn while sleeping, that contains wireless electrodes which would transmit to the clock.
In tests, the alarm time was set and a monitoring process of 90 seconds around that time began. Using brain activity, the clock monitored the sleep activity cycle during the 90 second period.
If a sleeper was in stage one or two, the alarm would sound to wake him or her. If the sleeper was in deeper stage three or four, the alarm would automatically snooze until a lighter stage of sleep was reached.
Findings were published in the Journal of Biomedical Engineering and Technology in October 2011.