Over the last few years there has been an increase in the use of novel consumer based wrist-activity monitors. Examples of these that most of you are familiar with are; Fitbit™, Jawbone™ and Misfit™ to name but a few. You may wear these devices to quantify your movement throughout the day in steps or kilometres or to quantify your sleep (hours) and or your sleep quality (percentage) overnight. So, you may ask yourself, how do these devices do this? Is it a heart rate monitor?, Is it a camera?
The answer is movement*, these devices utilise a tri-axial accelerometer to measure movement and their general operating principle in sleep-measurement is to define sleep as periods of “no movement” and wake as periods of “movement”.
One of these devices that has been gaining popularity is the Readiband™ and is the device that I have utilised with elite athletes in Super Rugby and with grappling athletes at the Australian Institute of Sport. This wrist-activity monitor was initially developed for use in military environments unsuited to regular type wrist-activity monitors. In addition to this, the Readiband has been used by police, physicians, mining, shift-workers, forestry industries and in elite athletes including the US National Football League. Mainly due to its robust design and the fact that it can withstand any condition.
Many of these devices including the Readiband have had limited or no published research validating the sleep measures provided against the gold standard in-laboratory polysomnograph (PSG). So, I conducted a study doing just that, comparing measurements of sleep obtained from the Readiband device and against another validated wrist-activity monitor to measurements obtained from PSG in a sleep laboratory.
It has now been published in the journal Sleep and Biological Rhythms. You can now view the paper “Laboratory and home comparison of wrist-activity monitors and polysomnography in middle-aged adults” in Sleep and Biological Rhythms via this link http://rdcu.be/wML2 . Please note, you cannot download a copy via the link, only view. There are no restrictions on the number of people you may share this link with, how many times they can view the linked article or where you can post the link online.
*The new Fitbits with heart rate monitors can use this data to also provide sleep stages based upon heart rate and movement.