And then there is the SleepTracker. Another interesting device.

Using a small accelerometer to measure certain types of lateral motion that correlate to lighter stages of sleep, SLEEPTRACKER continuously monitors signals from the body that indicate whether the person is asleep or awake. It uses those times of motion to give the user a picture of how many restless or light sleep periods they have throughout the night. The more recorded events, the more restless (i.e. worse) the night of sleep. The device also uses those recorded moments to detect lighter stages of sleep within an alarm window to wake the user at the optimal time in the morning.

It is a gadget that resembles a watch both in form and function, with the exception that you wear it overnight while sleeping and it monitors your sleep stages and wakes you up at your optimal "almost-awake moment". Unlike an ordinary alarm clock which wakes you up at a set time, regardless of whether at that moment you are in deep sleep or not, the SleepTracker Pro monitors how deep you are sleeping and chooses the best time (within a certain time window of your preferred wake up time) to sound the alarm. This ensures that you wake up refreshed.

In the early sleep cycles, the Delta sleep stages last longer than the REM stages. In the later cycles, the REM stages lengthen, whereas the Delta sleep stages decrease and eventually disappear. Each sleep cycle has multiple almost-awake moments when you are naturally closest to waking and these are the times when you want to be woken up.

What are the main features of the SleepTracker Pro sleep monitoring watch?

•Digital watch with time and date.
•Vibrating or ringing alarm or both.
•It monitors your sleep and wakes you at an optimal almost-awake moment.
•Alarm window (see explanation above) can be set up to 90 minutes.
•A chronological list of the previous night's almost-awake moments can be reviewed. It also calculates Data A i.e. the average time between your almost-awake moments.
•PC software to track your sleep patterns so that you can analyse why during some nights you have better sleep compared to others. Data download to PC via USB.
•Backlight
•Water resistant