Patches, rings, and other home sleep testing wearables are now available for medical use. Using novel biomarkers and cloud-based storage, these small tests are poised to make a big difference in sleep diagnostics.
By Lisa Spear
The first and only night I tried to doze off hooked up to a diagnostic sleep test, I worried so much about jostling the electrode near my collarbone free, or knocking the pulse oximeter out of place on my finger, that I barely moved, and hardly slept.
A few years have passed since then, and the pandemic, along with many technological advances, have led to the accelerated growth of available home sleep tests. Wireless sensors, once unheard of in sleep diagnostics, are rapidly becoming more common. In just the last few years, about half a dozen wireless home sleep tests intended for professional use have entered the market, have received nods from the US Food and Drug Administration (FDA), or have entered clinical trials.
For instance, the Sunrise attaches to the patient’s chin with an adhesive and records jaw movement throughout the night. The whole device is no bigger than a peanut and weighs no more than 3 grams.
“Tests like these can be very helpful in the sense that they expand the number of people who can have these tests readily available,” says associate professor of psychiatry Jamie Zeitzer, PhD, of Stanford Center for Sleep Sciences and Medicine, who is not affiliated with any wireless sleep test companies. He cautions that not all devices are created equal and encourages clinicians and scientists to review efficacy data for the systems they wish to use.
Traditional wired home sleep tests that measure respiratory signals are still the most common choice among professionals in the field, but some sleep specialists are eyeing alternative, wireless devices that use different biomarkers to help decode the physiology of sleep.
The Sunrise patch, for instance, records movement from a single sensor on the chin.
“We have developed the measurement of a new biosignal: We analyze mandibular movements during sleep,” says Laurent Martinot, co-founder and CEO of the company Sunrise.
Artificial intelligence pores over the data to detect changes that could indicate sleep apnea and an auto-generated report is delivered directly to the physician.
Research backs up Sunrise’s innovative approach. A recent study, conducted at a university sleep laboratory in Belgium and published in JAMA, compared the chin patch to polysomnography (PSG). The prospective research evaluated 376 adults with suspected obstructive sleep apnea who were referred for a single overnight PSG study. The participants spent the night in a sleep lab for their PSG, which recorded typical sleep study biometrics, including brain activity, chest motion, blood oxygen saturation, nasal airflow, and others.1
Simultaneously, the Sunrise chin patch monitored jaw movements alone. No other biometrics were taken, and according to the study results, this single-sensor test accurately documented respiratory disturbances and is a suitable alternative to an overnight stay in a sleep center. And unlike the traditional PSGs, artificial intelligence scored the Sunrise data automatically without the help of a sleep tech.1
“This saves time and makes diagnosis easier,” says Martinot.
Sunrise is far from the only company that is reimagining what home sleep testing looks like.
The AcuPebble SA100 is another wireless diagnostic sleep test that is small enough to fit in the palm of a person’s hand. Worn at the base of the neck, AcuPebble devices sense the physiological sounds generated by the body, detecting respiratory and cardiac disease biomarkers. Validated in a clinical trial at the National Health Service’s Royal Free Hospital in London, the device was found to record data equivalent to cardiorespiratory polygraphy.2 AcuPebble SA100 received FDA clearance in 2021 and the marketer, Acurable, is opening a US office this year.
The data demonstrate that not only is AcuPebble SA100 accurate in diagnosing obstructive sleep apnea with specificity of 96.8%, it also does not require any training for patients to deploy the device at home.2
It is comfortable, too. “Users say they can barely feel it,” says Emilio Sanz Pereiras, Acurable CEO.
The SleepImage Ring is also a single-sensor wireless sleep test with FDA clearance. Designed with a rubbery material, the device is slipped on a finger before bed.
It contains a photoplethysmogram sensor that detects blood volume changes in vascular tissue, heart rate, and oxygen saturation. The SleepImage software uses its own sleep-disordered breathing measurement system, the “SleepImage Apnea Hypopnea Index” or “sAHI,” an automated scoring index that adheres to the American Academy of Sleep Medicine’s scoring guidelines.
“The system was developed for the non-sleep physician, so everything is very simple,” says Solveig Magnusdottir, MD, medical director of SleepImage.
Bluetooth connects the ring to the patient’s mobile phone or tablet, then the data is sent to SleepImage’s cloud software, where it is automatically analyzed, and a report is delivered to the clinician within minutes.
Based on technology that is clinically validated, the SleepImage Ring records sleep-disordered breathing comparable to an in-lab test for both children and adults.3 And the device is cleared by the FDA for the diagnosis and management of obstructive sleep apnea.
“One of the big benefits is the ease of use,” says Bogi Palsson, CEO of SleepImage. “Literally anyone who can wear a ring and open an app on a smartphone will be able to take the test without any difficulties.”
SleepImage generates a color-coded report that reviews sleep pathologies, breathing disruptions, sleep duration, and sleep quality. No specialized sleep medicine training is required to read the report: Primary care providers, cardiologists, pediatricians, or dentists should find that the document is easy to understand, according to Palsson.
Another plus, Palsson adds, is there are no disposable sensors or parts that must be continuously replaced. The total cost of the ring is $299.
“The SleepImage ring is reusable, so the cost is minimal over time, with multiple patients,” says Palsson. The software that analyzes the data comes separately and the price varies based on the practice’s size.
Physicians can also choose to monitor their patients with multiple nights of data, an advantage over many devices in the wired category. The lack of wires facilitates more comfortable testing and cloud storage means more space for data. “We see this as an opportunity to improve access to care and improve outcomes for the patient,” says Palsson.
Another company, Wesper, created a home sleep test composed of two 3-inch wireless patches that are worn on the abdomen and thorax. Coupled with a smartphone app, the sleep test system received FDA clearance this year to diagnose sleep apnea.
Separately, Onera BV designed a patch sleep test. It has a CE mark, allowing sales in Europe, and is pending FDA approval.
Many health tech companies developing these compact, wireless diagnostic devices say that their goal is to increase access to sleep testing. Some also envision a future in which sleep tests will not be reserved only for people with suspected sleep apnea but rather be available to the public at large.
“Sleep is a vital sign to health,” SleepImage’s Magnusdottir says. “Our hope is that everyone can have access to a sleep test. We hope to be able to implement sleep testing, like a blood pressure monitor, to improve the health of everyone.”
Lisa Spear is associate editor of Sleep Review.
1. Pépin J, Letesson C, Le-Dong NN, et al. Assessment of mandibular movement monitoring with machine learning analysis for the diagnosis of obstructive sleep apnea. JAMA Netw Open. 2020;3(1):e1919657.7
2. Devani N, Pramono RXA, Imtiaz SA, et al. Accuracy and usability of AcuPebble SA100 for automated diagnosis of obstructive sleep apnoea in the home environment setting: an evaluation study. BMJ Open. 2021;11:e046803.
3. Al Ashry HS, Ni Y, Thomas RJ. Cardiopulmonary sleep spectrograms open a novel window into sleep biology-implications for health and disease. Front Neurosci. 2021;15:755464.