The Sleeptracker watch uses an accelerometer to track periods of motion while sleeping. It uses this information to log times of motion and to identify an optimal time to wake the user in a pre-determined window before a wake-up time. Overall, it provides an easy way to track the amount of undisturbed sleep time a user experiences, but wasn’t consistently able to wake this reviewer before the set alarm time.
I used the Sleeptracker Standard over a week period. The watch is made by Innovative Sleep Solutions LLC. out of Atlanta, Georgia. You can read in detail on the product website how it works, but basically you’re strapping an accelerometer to your wrist. Prior to sleeping you set the time you’re go to bed (so the watch knows to start tracking), what time you want to wake up by, and the window of time before the set wake-up time during which the watch can go off. If within that window it notices that you’re out of deep sleep and are moving around, the alarm will ring. If you don’t move within the set window, the watch will wake you up at the set alarm time like a normal alarm clock. After wake-up, the watch will display all of the times you moved during the night and the average non-moving times over the entire sleep period.
I logged all of my results on my twitter account (@MedGadgetDan), which you can follow if you want a sense of the day-to-day activities of a Medgadget editor.
The concept of the watch uses a model of physical activity as a proxy for sleep stages, which is usually measured by EEG. The limitations of using an accelerometer for this measurement are amplified if you don’t sleep alone. The movements of your partner (or partners) can be enough to trigger a recording event on the watch. I have a partner with an overlapping, but different sleeping schedule than me, and the data was a little bit more reliable during the times she was not in bed. Of course, my quality of sleep is probably greater during those times as well. This view was confirmed by Ale Menchaca, a grad student who recommended I review the device after she had a good experience with it. She has used it for over 40 nights and said, “I like it as a monitoring device to get an idea of how well I am sleeping, not so much as an alarm clock.” Her average times were comparable to mine and she also noted that her average undisturbed sleep period was twice as long on nights she was sleeping alone in bed compared to nights with her partner.
I used the $99 version, featuring an audible alarm. More advanced models of the watch are more expensive, but offer the option of a vibrating alarm and a method to offload results to a computer for more advanced analysis. I’d caution about using the average sleep time the watch provides as a measure unless you have consistent sleep and wake times. A usual sleep pattern will be 3-4 periods of long deep sleep (as seen in the below image) followed by periods of shorter lighter sleep. It would probably be most useful to take the tracked times and figure out how long after going to bed you start to encounter shorter periods consistently, and plan your sleeping times around that.
Product site for all models: Sleeptracker…