There are a number of products on the market that claim to be "better alarm clocks" that allows you to feel more refreshed when you wake - even if you sleep a few minutes or tens of minutes less.
There are two claims:
that one feels more refreshed if one wakes during the REM phase of a sleep cycle, and
by monitoring movement as one sleeps, devices can determine the sleep cycle.
Examples of products that make such claims include:
SleepTracker’s SmartStart Technology monitors your sleep stages throughout the night and then uses that data to determine the exact moment when you should be awoken helping you feel refreshed and energetic. 1
Do these alarm clocks really make you feel more refreshed? Is such a thing feasible?