The tech that wants to help you sleep

The tech that wants to help you sleep
Image: Illustration by Hoi Chan
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Table of contents

Intro | The science of sleep | A brief overview of sleep tech | The future of sleep tech


During the pandemic, I just could not fall asleep. I tried all sorts of common interventions: less coffee, more yoga, blue light-blocking glasses, and Twitter-blocking apps. At night, I banished my phone and laptop to the other side of my bedroom door. Nothing seemed to work.

Then I discovered that the meditation app I’d been using hosted a library of bedtime stories—pleasantly uneventful tales about train journeys and nature hikes, read by various gentle-voiced narrators as if to a sleepy child. Out of desperation one night, I listened, skeptical that the deep voice of the actor Cillian Murphy, murmuring about Ireland’s coasts, could actually deliver me unto dreamland.

I fell asleep in minutes. Since then, bedtime stories have become a consistent part of my nightly routine. More than just a lovely reminiscence of childhood, they’ve become a necessary distraction from my usual bedtime habit of getting under the covers and freaking out about everything going wrong in the world.

Like many people, I’ve had trouble sleeping because I’m stressed and anxious about the pandemic—a condition some health experts have termed “coronasomnia.” A wealth of anecdotal evidence shows that people struggled to sleep during the pandemic. And a handful of studies support these trends: One paper, a meta-review of 44 studies on sleeplessness during Covid-19, concluded that 40% of people across 13 countries were having trouble sleeping during the pandemic. US Google searches for insomnia rose 58% in the first five months of 2020. Another study revealed a 20% uptick in sleeping pill use between March and April 2020.

But sleeplessness plagued us long before Covid-19. Data collected by the US Centers for Disease Control and Prevention in 2014 shows that more than 35% of US adults get fewer than the recommended seven hours of sleep, and close to 50% say they get sleepy during the day multiple times a week. In a 2012 study on sleeplessness in Africa and Asia, World Health Organization scientists warned of a “global epidemic” of sleep problems. Even prior to the pandemic, Google searches for “insomnia” were already spiking every night around 3am.

Therapy and medication are the gold standard of treatment for sleeplessness. But in recent years, there’s been an explosion of gadgets and apps promising better sleep through technology. Meditation apps, like the one I use, are just the tip of the consumer sleep-tech iceberg. Sleep-monitoring bracelets, brainwave-stimulating headbands, motion-sensing mattresses, and even huggable robots now make up a market that was worth $12.5 billion in 2020 and is expected to more than triple in value by 2027, according to Global Market Insights, thanks to an increasing prevalence in sleep disorders.

Sleep scientists who talked to Quartz say that while some devices can help—if they’re used correctly—others rely on nascent, unproven technology. The question to keep in mind when looking for a sleep gadget is why you can’t sleep in the first place: Much like traditional therapy aims to do, the devices that are most likely to help are those that tackle sleeplessness at its root.

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The science of sleep

Modern society has an unhealthy relationship with sleep, says Michael Grandner, director of the Sleep and Health Research Program at the University of Arizona. “We see sleep as the enemy of productivity,” he explains.

Our biology would disagree. Humans evolved over millennia to survive an endless cycle of night and day. The end result was a species with a parallel rest-activity cycle that uses energy when the sun is up and repairs itself when it’s dark.

During sleep, the brain and body internalize everything that happened to it when it was awake. Experiences become memories. Attacks on the immune system lodge in biological memory, in preparation for future assaults (that’s why, Grandner explains, people who sleep less tend to get sick more). Meanwhile, it appears that the brain cleans house at night, washing away metabolic trash with waves of cerebrospinal fluid so it can run smoothly the next day.

Among the multitude of factors that have been blamed for our inability to sleep are stress, anxiety, caffeine, the news, alcohol, social media, working too much, not having work to do, and blue light—all of which are, arguably, artifacts of our productivity-obsessed culture.

The pandemic complicated our sleep issues further by disrupting our daily routines. For many, “office hours” became obsolete, along with the office. Mealtime was anytime, and outdoor time was never. It’s only natural that these disruptions in daytime living are reflected in nightly life, says Grandner.

The consequences can be serious. Often, lack of sleep leads to irritability and difficulty concentrating. Mental health issues, like depression or anxiety, may worsen. It’s been linked to a higher risk of chronic illnesses like heart disease, type 2 diabetes, and obesity. Some studies even suggest a link to Alzheimer’s and dementia.

The most common treatment for sleeplessness is cognitive-behavioral therapy for insomnia (CBT-I), which aims to establish and maintain healthy habits around sleeping, sometimes collectively known as “sleep hygiene.”

A CBT-I therapist might help you reduce stimulation before bed by avoiding caffeine or turning off the late-night news. They may teach you how to relax using stress and anxiety management techniques and help you optimize your sleeping conditions.

Sleep tech will most likely never take the place of a trained therapist. However, there is room for some gadgets, especially those designed by scientists or with scientific principles in mind, to help achieve some of the same goals as CBT-I, leading to better sleep. Rebecca Robbins, an associate scientist at the Brigham and Women’s Hospital and an instructor at Harvard Medical School, says technology that’s married with evidence-based principles—she points to apps developed to support CBT-I treatment as an example—is a “home run.”

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A brief overview of sleep tech

There are so many sleep apps and gadgets on the market that it can be hard to know where to begin, let alone find a device that’s based on sound science. The growth of the sleep tech industry in the past five to 10 years has been attributed to advances in technology, increases in sleep disorders, as well as a better understanding of the consequences of losing sleep.

Massimiliano de Zambotti, a research scientist at the nonprofit SRI International’s Human Sleep Research Program who studies wearable sleep devices, thinks about sleep tech in two broad categories: sleep trackers and devices for “augmenting sleep.”

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Sleep Trackers

True to their name, sleep trackers, which encompass wearable bracelets and rings that pair  with phone-based apps, in-bed sensors, and contactless “nearable” sensors, track metrics associated with sleep. The apps then serve that data to the user, either in the form of raw numbers or simple graphics.

The most basic are smartphone apps that use a phone’s internal accelerometer to track how long a person keeps still, and therefore is presumably asleep. Some also listen to you sleep using the microphone, keeping tabs on sleep-talking, snoring, and shifts in breathing patterns. Hundreds of these apps are available for iPhones and Android phones, but the research, says de Zambotti, suggests they’re generally unreliable. By one study’s estimate, accelerometer-based measurements are only 78% accurate in determining when you’re actually asleep.

There’s much more research on wearable sleep trackers, like those by FitBit, Lintelek, and SleepOn, as well as the Oura Ring, which the National Basketball Association went crazy for last year. Of these, FitBit has received most of the attention. As a class, says de Zambotti, wearables are pretty good at tracking certain sleep metrics, such as heart rate and breathing, movement, time spent sleeping, disturbances throughout the night, and, in electrode-equipped devices like the Dreem headband, time spent in different stages of sleep. Smart watches, like those by Garmin or Apple, track similar metrics. Wearables broadly hold up against polysomnography (PSN), the “gold standard” tracking method used in sleep labs, de Zambotti says, but it’s difficult to generalize performance across brands and devices since companies use different standards for assessing their products.

Nearables, sleep trackers that are not worn, are essentially movement and auditory sensors placed inside or built into bedroom items. A sleep tracking mat by Withings tracks movement from under the mattress; a wifi-equipped pillow from iSense measures tossing and turning. Amazon recently unveiled an Alexa-powered sleep tracker called Sleeptracker, and Google’s Nest Hub has a new Sleep Sensing feature. You can even get a smart bed from ReST that not only tracks your sleep but also automatically adjusts to changes in pressure, if you’re willing to shell out up to $8,000 for it.

Whether they’re worn or stand by while you sleep, all trackers serve one purpose: to gather information to share with the user. And that’s why they can be problematic—a lot of users have no idea what to do with the data.

“They hope, basically, that by providing you feedback, you take action upon your feedback,” says de Zambotti. “It’s pretty risky, because you leave to the consumer the interpretation of this data.” It’s hard enough for specialists to do so, let alone the average person, he adds.

“No one has taught users and consumers how to interpret those data,” says Azizi Seixas, a sleep expert and assistant professor at NYU Langone medical center who also does scientific consulting for sleep tech companies. Your FitBit could tell you how much deep sleep you had, he says, “But what does that mean? How does that impact your health? There needs to be more education in those digital solutions or programs.”

The consequences of misunderstanding data can be serious. Devices that track awakenings throughout the night tend to overestimate, or fail to acknowledge the small awakenings that normally occur in the transition between sleep stages. This makes some users panic. People will “rush to their doctor and think they might have cancer, or something that’s really scary that caused them to wake up many times that night, when in fact they are completely healthy,” Robbins says. The toll on the healthcare system is “significant,” she says.

It doesn’t help that humans are generally bad with numbers, she adds. As companies realize that people struggle with numeracy, they’re focusing on providing users with visual interpretations of the data to convey how well they slept. A bar graph could show sleep trends over time, or a completed circle might be used to mark a full night’s sleep. Rewarding people for good sleep behaviors can be beneficial, says Robbins, but there are drawbacks to this sort of gamification: One research group found that sleep tracking data can make people even more anxious about sleeping. This condition is called orthosomnia: an unhealthy obsession with getting perfect sleep and can itself impair sleep.

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Sleep augmentation

Tracking sleep is one thing. Actually falling asleep—and staying asleep—is another. The desire for better, longer, more instantaneous sleep has created a class of products de Zambotti calls “sleep augmenters,” or apps and gadgets that claim to make you fall asleep faster and get a better night’s rest. Sleep apps that digitally deliver CBT-I, like Sleepio, Somryst, and the CBT-i Coach developed by the Veterans Health Administration, help people sleep by changing detrimental thought patterns and behaviors through an evidence-based approach. But a wide range of other sleep augmenters exist, with varying degrees of scientific backing.

An entire branch of these products is dedicated to optimizing sleeping conditions. Customizable lighting like the Philips Smartsleep and Casper Glow Light, which emit different types and intensities of light depending on the time of day, seems to be especially popular, with the forecasting company Fior Markets estimating that the light therapy market will be worth $1.35 billion by 2021. The idea is to expose the user to the wavelengths of light they would naturally encounter over 24 hours—blue and green wavelengths in the day, and red at night—to maintain their circadian rhythm, which is tied to nature’s light-dark cycle.

These products are attempting to solve a real problem: the surrender of the circadian “day” to the eternal sunshine of artificial light. “We’ve sort of made the night optional,” says Grandner. “We don’t get a good ‘dawn’ signal in the morning because we’re in the dark, and then we don’t get a good nighttime signal when the sun goes down because we have all our lights on and we’re looking at screens where the light goes straight into our eyes.” Blue light-blocking glasses, meant to mitigate the blue light from our screens that screams “sunlight” to our brains are based on the same idea, as are blue light-emitting alarm clocks claiming to wake you up naturally by simulating the sunrise. While the theory behind these products is scientifically sound, whether these devices actually help people sleep remains to be seen.

Sleep can be optimized through other senses, too. White noise machines and playlists of soothing sounds—think babbling brooks or whispering pines—block out jarring noises that may wake a light sleeper. Ditto for noise-canceling headphones. Temperature modulation is built into smart mattresses like the Eight Sleep Pod, which senses a user’s body temperature and heats up or cools down accordingly and also offers the option to be woken up with gentle vibrations in lieu of an alarm. There are even scent-based devices, like the SensorWake olfactory alarm clock (soon relaunching as Maison Berger’s Night and Day Diffuser), designed to wake you up gently with the smell of freshly brewed coffee or warm croissants.

A newer crop of sleep augmentation devices is based on an old scientific technique called biofeedback, a method for controlling involuntary bodily functions associated with stress and anxiety, like increased breathing rate or heart rate. Biofeedback devices use bodily sensors to collect data on these functions and display it on a screen so users can become aware of and modulate it in real time. Some FitBits, for example, are equipped with animated biofeedback programs to regulate breathing rate. A few devices monitor brain activity via electroencephalography (EEG), like the FocusCalm and Muse headbands, and claim that this data can be used to steer one’s mind toward a more relaxed, sleep-optimal state through neurofeedback.

There isn’t enough independent research to determine with confidence whether biofeedback gadgets actually help people sleep. But generally, those focused on respiration are the most promising, says de Zambotti, in part because they’re based on the well-established idea that slowing down breathing creates a sense of calm.

Julian Martijn Jagtenberg poses with a Somnox Sleep Robot, which mirrors your breathing for a better night's sleep, at "CES Unveiled" during the 2019 CES in Las Vegas
The Somnox Sleep Robot at CES in 2019.
Image: REUTERS/Steve Marcus

Of course, biofeedback devices aren’t the only way to slow one’s breathing. There’s no shortage of apps that let users sync their breath with soothingly rhythmic animations. In mindfulness meditation, breath control is a core skill. For the cuddling-inclined, the Somnox sleep robot mimics the gentle expansion and contraction of the human breath, encouraging the person snuggling it to sync their breathing up with it.

“We know from research that if you have an altered psychophysiological state before starting to sleep, when you are attempting to sleep, it’s bad,” de Zambotti says. Whether a device works through lights, sounds, smells, hugging, or biofeedback, if it puts you in a more relaxed state before bed, it’s probably a good thing.

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The future of sleep tech

Despite its rapid growth, sleep tech is still in its early stages, and it’s unlikely to replace professional help anytime soon. But sleep trackers do a good job of raising awareness around potential sleep issues, says de Zambotti, and pairing data from those devices with therapy or medical intervention could eventually become very useful.

This data could also revolutionize the science of sleep. Seixas envisions a future where tracking devices are held to standards established by the US Food and Drug Association; the data they collect could be used not only by healthcare professionals to treat patients, but also to study differences in sleeping problems at a massive scale. “If we have more standardized big data, then we will be able to do more sophisticated deep analytics,” he says. Doing so could lead to a more granular understanding of the reasons people can’t sleep, and precision treatments for different issues.

But at the end of the day, even the most sophisticated tech probably won’t cure our collective insomnia. Devices can help us create good rhythms, explains Robbins, but the best sleep is natural. “It’s not something we can program using a device,” she says. “You can use a thousand different gadgets,” adds de Zambotti, “but if you are always drinking four cups of coffee at 10pm, you can use whatever gadget you want; you’re probably not going to sleep.”

As long as our culture remains at war with sleep, adapting our behavior around it will be critical. In many cases, this means trying our best—with or without gadgets, apps, or bedtime stories—to relax, and giving ourselves ample time to do so. A common misconception is that the brain functions like a switch, winding down as soon as the lights go off, says Grandner. A much more helpful metaphor is to think of the brain going to sleep as a car approaching a stoplight at an intersection: In order to stop at a certain point, it needs to slow down well in advance.

People are active all day, then they get into bed and that’s when they start tapping the brakes, he says. “They’ll say, ‘I just can’t slow my mind down.’ Well yeah, you’re still moving in that intersection because you just started winding down.”

In a world where constant stimulation is the norm, being deliberate about carving out peace and quiet is paramount for good sleep. Keep electronic devices out of the bedroom, have a consistent nighttime routine, and avoid big meals and alcohol before bed. “The intersection isn’t there too quickly. It is where it is,” Grandner says. “You either budget for it and plan for it, or you’re going to move into that intersection and get frustrated.”