£135, from sleeptrackerpro.co.uk
This device, which is worn on your wrist, detects movements while you sleep. It also has an alarm you can set to wake you when the sensor detects increased movements. This indicates light sleep, so waking up is easier.
EXPERT VERDICT: ‘Do you really need a machine to tell you if you’re sleeping badly? Also, while this claims to wake you at an optimal time, if you’re already moving around, you will naturally wake up at this point anyway.’
MANUFACTURER’S COMMENT: ‘The Sleeptracker is not designed to improve your sleep, but waking up. It uses proven science to work with your body’s sleep patterns and rouse you from light sleep when the discomfort of being woken is least.’