How did you sleep last night? If you just consulted your sleep tracker, you’re not alone.
With the $2.2 billion activity-tracking industry zeroing in on zzz’s, more people are turning to technology in their quest to get a good night’s sleep. But most trackers — from lifestyle wearables like FitBit and Jawbone to apps like Sleep Cycle and Sleepbot — have one thing in common that could be throwing off their intel. They rely only on monitoring movement, using a technology called actigraphy, to determine when you are awake, asleep, or somewhere in between. In other words, they’re simply misreading all stillness as dead-to-the world sleep.
Research published in the journal Sleep & Breathing shows that actigraphy often results in these devices overestimating sleep quality and quantity. In fact, when researchers compared FitBit technology with more sophisticated polysomnography (PSG) recordings (used in sleep labs to monitor physiological functions including brain activity, eye movements, muscle activity, and heart rhythms) the results were quite different. In a study of 24 sleepers, the FitBit recorded an average sleep efficiency (the ratio between actual sleep time and time spent falling asleep) of 94 percent and total sleep time of 7 hours and 18 minutes. Meanwhile, the PSG results came in at 79.5 percent efficiency at 6 hours and 11 minutes.
For most people, that’s probably not a life altering difference. But it is pretty troublesome for those who simply can’t figure out why they’re waking up still wiped out — possibly because of undiagnosed sleep disorders. Take, for instance, those with sleep apnea, in which breathing periodically stops and starts throughout the night. While sleep apnea causes frequent wake-ups, it rarely causes movement, according to study researcher Hawley Montgomery-Downs, Ph.D., coordinator or the Behavioral Neuroscience Training Program at West Virginia University.
Can a Gadget Help You Sleep Better?
Enter the Beddit sleep monitor. Developed by a Finnish sleep technology company, in partnership with the Helsinki Sleep Clinic and VitalMed Research Center, this $149 tracker, which is available for online purchase in the U.S., determines sleep quantity and quality using much more sophisticated technology. Namely (if you can pronounce it), ballistocardiography. Or BCG, for short.
“By following your sleep habits from night to night, you can see the evolution of your sleep.”
When you place Beddit’s long, sticky-backed sensor across your mattress so your chest, back or side lies against it, BCG technology is able to track every one of your movements, heartbeats, and breaths throughout the night. The device is plugged into the wall and the companion smartphone app instructs the device when to start recording. The app even uses your phone’s microphone to detect snoring, which is indicative of disturbed sleep and apnea — and combines it with BCG info to determine if it’s really you (or an obnoxious bed buddy) that’s sawing logs.
“By adding information about heart rate and respiration to information about body and limb movements, one can have better estimation of sleep stages, length of sleep and about quality of sleep,” says sleep researcher Markku Partinen, M.D., Ph.D., director of the Helsinki Sleep Clinic and founder and CEO of VitalMed. For instance, in active REM sleep, breathing and pulse may be irregular, and small muscular twitches are common. However, in calm, deep wave sleep, breathing and pulse is slow and regular, and movements are more than rare, he says. A device that can differentiate between the two can help you figure out if you’re getting enough of each — and prompt you to take action if you’re not.
What’s more, the combination of actigraphy and BCG technology in the device provides better information about the causes of a disturbed night’s sleep — be it sleep apnea, insomnia, or severe limb movements, Partinen says. The app’s dashboard displays your night’s total sleep score, sleep time, resting heart rate and respiration rate, along with a chart detailing your hour-by-hour sleep stages.
If Beddit reveals you are waking up constantly, snoring, and your respiratory rate is irregular, it may recommend getting checked for sleep apnea. (Partinen does note, however the device is not meant for medical diagnoses. If you do believe you might have a sleep disorder, you should visit a specialist.)
“Many know that they have issues with sleep, but a proper quantification of it helps…” he says. “By following your sleep habits from night to night, you can see the evolution of your sleep.” Then, based on that data, the app provides tips on how to shore up your sleep shortcomings — from relieving stress through progressive muscle relaxations to reserving your bed for sleep and sex.
To learn more about Beddit Sleep Monitor, head to beddit.com.