1. Zeo

The Zeo Personal Sleep Coach is the first at-home device that allows people to track their sleep cycles over time.

During the night, the user wears a soft headband with an embedded sensor that detects the brain's electrical activity. That information is used to determine the user's stage of sleep—light, deep or REM (when we dream)—and wirelessly sent to a bedside base station.

In the morning, the display unit gives a summary of the previous night's sleep, including how long a user slept, how many times she woke up, and the amount of time she spent in the various stages of sleep. A small memory card within the display unit stores the data, which can then be transferred to a computer and uploaded to a website that tracks the user's sleep trends and offers advice for improving sleep. (The company is careful to point out that the Zeo is not a medical device and cannot diagnose sleep disorders.)

Thus far, Zeo, a start-up based in Newton, Massachusetts, has compiled the largest database—by two orders of magnitude—of sleep-stage information in the world. The company has made the database open to the public, enabling scientists and others to look for trends in sleep patterns, such as whether people sleep less during the full moon.

http://www.myzeo.com/

Cost: $199

Available now

Credit: Winnie Wintermeyer