Science-- there's something for everyone

Wednesday, October 26, 2011

Easy wake alarm


When I was a kid, my brother and I played a board game called ‘The Inventors’ which featured an ‘E-Z wake alarm’.  This alarm system was essentially a rope tied to a payload precariously placed above the sleeper’s head.  Jemina Sylvia from the Jerusalem College of Engineering led a team in developing a gentler way to wake people up.  They link their alarm clock to the slumberer’s electroencephalography (EEG) waves so that he or she can be awoken during the least jarring part of the sleep cycle.

As people doze, they alternate between rapid eye movement or REM sleep, the stage at which most dreaming occurs, and non-REM sleep.  There are four stages of non-REM sleep, each progressively deeper than the previous stage. The various sleep stages can be distinguished by EEG waves.  As you can see in the hypnogram below, most people follow 90 minute patterns of REM through stage 4, then REM again.

In this study, volunteers were hooked up to EEG monitors as they slept, and the output was sent to their alarm clocks, which were programmed not to awaken them if they were in stage 3 or 4.  Instead, the clock waited until the sleeper was in one of the lighter sleep stages before sounding.

As of now, the device has some drawbacks, not least of which is that the sleeper has to wear scalp electrodes that are wired to a clock—not exactly what the person seeking a more pleasant sleep experience is looking for.  However, the researchers expect that a headband containing wireless electrodes could do the trick.  And of course, there’s the question of whether people will be late for appointments if their clocks wait for a more convenient time to wake them.