This week Fitbit announced that their newest trackers such as the Alta HR, Blaze and Charge 2, will soon be capable of delivering sleep data which was previously available through a sleep lab only. Let’s take a closer look at this new feature called Sleep Stages.
Previously, Fitbit’s line of trackers merely correlated accelerometer recorded sleep data and machine learning algorithms to qualify sleep.
With continuous HR in select new trackers (the newer editions), heart rate variability was added to the formulation of new sleep tracking algorithms capable of estimating light, deep and REM sleep stages. Traditionally Polysomnography, or what is termed a sleep study to the layman, involved the recording of brain waves, eye movement, blood oxygen levels, respiratory and heart rate, as well as limb movements. Thereafter the results are interpreted by the sleep center doctor. Doesn’t sound like something a $150 activity tracker is capable of doing does it? Well it’s all about big data these days.
Fitbit took 2 years and worked with industry-leading sleep experts from Johns Hopkins University, Stanford University, and the University of Arizona in the development of the sleep stages data. The company conducted extensive and detailed observation and analysis of several hundred nights of heart rate and movement data from volunteer sleepers while bench marking that to information from sleep study equipment.
While the presented sleep stages is unlikely to rival that of a properly conducted sleep study, it does provide an estimate which is easily available on a daily basis.
Apple’s Series 2 Watches have yet to feature native sleep tracking so Fitbit’s sleep stage data announcement is just about the most advanced sleep tracking available for wrist worn fitness trackers. If there’s one thing the company is doing right at present, it is the fortification of its wearables with more consumer relevant features such as sleep data.