The world is home to many strange things, and Sony doesn't think it would hurt anyone for another strange idea to bear fruit.The company has submitted a patent for a pillow with integrated electrodes (USPTO).
Said electrodes act as sensors and read brainwaves, determining when people fall into a deep sleep or come out of it.
A timer would be started once people fall into a light nap, but the alarm, or the bed motor or whatever else, wouldn't go off if the sleeper falls in a deeper state (or REM sleep).
Instead, it would read the brain waves and determine when the person comes out of REM (rapid eye movement, when dreams happen) and only then start the buzzer or flashing light, bed shaking, etc.
As far as actigraphy goes (non-invasive method of monitoring human rest/activity cycles), pillows like this might be quite easy to get used to.