Technological breakthroughs are coming in thick and fast in our modern age. In the last decade alone, the size of processors has shrunk dramatically, allowing for new technology to be implemented in smaller devices.
First, it was computers, then smartphones, then smartwatches, but now smart rings are the next big thing. Tiny, wearable devices capable of tracking a wide range of body metrics. This makes them ideal for users who want to track their fitness on runs, in the gym, or even when swimming. However, the small size of these devices also makes them perfect as sleep tracking devices.
While a wearable like a headband or a smartwatch can be an inconvenience and a bedside sleep monitor isn’t always accurate, a ring is both close enough to your body to collect lots of data (things like breathing, pulse, and oxygen levels) and small enough to be comfortable and discreet.
This article will examine what kind of technology is used for sleep monitoring with smart rings, how accurate they are, and which are the best ones on the market in 2022.
What Technology Do Sleep Tracking Rings Have?
Smart rings are usually designed to do just a few specific things, but the tech that can be packed inside a ring is quite remarkable. Some of the most common features found in smart rings include:
The ideal way for a smart ring to sync with smartphones or other devices, Bluetooth can transfer lots of data–including sleeping data–from your ring so that it can be analyzed accurately by algorithms within apps. Those apps on your smartphone can then turn that raw data into graphs, charts, and recommendations for small changes to your habits that could help your sleep.
Near-field communication (NFC)
This type of wireless communication allows data transfers from one device to another. NFC makes use of a small magnetic field that can be registered when two devices are in close contact. Just by tapping your ring near a tablet or phone, you can transfer all of the data it has collected. This is the same technology used to check out and pay for things at terminals.
Heart rate monitor
Using either optical technology or infrared, heart rate monitors pick up on the tiny electrical impulses that flow throughout your body and turn it into an accurate measurement of heart rate. When it comes to monitoring sleep, heart rate has a key role to play. As you drift from light to deep sleep, your heart rate usually drops to signal you are moving from one stage to another.
This sensor measures your movements when you are running, swimming, walking, or doing another activity. It is also used in sleep rings to gather data on how much you are moving around in the night. This can help you understand what sleep stage you are in at a given time and how long you typically spend in each stage.
A gyroscope moves as you move, rotating on multiple axis points to give information about balance and movement. If you are sleeping and don’t remember moving around in the night, the data gathered from the gyroscope in your smart ring can paint an accurate picture of your nocturnal tossing and turning. The best sleep trackers combine this data with an accelerometer to offer even more precise movement data.
Some smart rings are beginning to include electrodermal activity sensors. An EDA sensor measures the electrical conductivity of your finger. It can give information about your stress level and even make an educated guess regarding your emotions by detecting minor increases in skin conductivity.
Blood oxygen sensor
Also known as a SpO2 sensor, a blood oxygen sensor can measure the oxygen saturation in your blood. While this is great for measuring the intensity of physical activity, it also has a role to play in monitoring sleep. Some sleep disorders such as sleep apnea cause insufficient oxygen intake at night, which can cause disturbances in sleep. This monitor detects such declines in oxygen levels and may be able to give you a heads up to see a doctor.
Sometimes, people lose out on sleep because they are woken by being too cold or too warm at night. A thermistor will measure your skin temperature throughout the night and give you vital feedback in the morning. This is also an excellent sensor for detecting night sweats. These can cause sleeping issues and can sometimes be symptoms of health problems.
Top 5 Sleep Tracking Rings
- Oura Ring: Developed to help you understand your overall circadian rhythm throughout the day and night. This is one of the top performing rings on the market. It tracks everything from heart rate and respiratory rate to your skin temperature and body movements.
- Movano Ring: With sensors including heart rate, respiration rate, and blood oxygen saturation, the Movano is a great choice of smart ring for sleep monitoring. It monitors both your sleep activity as well as daytime exercise regime, and links them to show you how exercise affects sleep patterns.
- THIM: A smart ring that doesn’t aim to track every kind of metric. This ring is designed to help people who find it difficult to get a good night’s sleep. Research has shown that this ring is able to help users get more sleep every night and reduce the time they spend wide awake.
- Circular Ring: This plastic device benefits from a heart rate detector as well as an accelerometer. Giving you the ability to track both your daytime exercise and night time sleep patterns. It can track your levels of SpO2 and use these metrics to determine your optimized circadian rhythms.
- Go2Sleep: This aptly named sleep ring from Sleepon is compatible with both Android and iOS devices. It sports a wide range of tracking sensors including blood oxygen monitoring, heart sensors, and motion detectors in the form of both a gyroscope and accelerometer.
How Does Sleep Monitoring with Smart Rings Work?
Some sleep monitoring smart rings require you to put the ring on your index finger. Others work better with a thumb reading. Since smart rings don’t have screens, your sleep information must be displayed on an external device. In the morning, all you have to do is send the data from your ring to your computer, tablet, or smartphone. It is then analyzed and collated into graphs and charts so you can easily see what has happened overnight.
A compatible sleep tracking app will present the user with all the metrics measured during the sleeping period. And, in most cases, will turn your data into a sleep score, then suggest what you can do to improve your sleep through changes in habits.
How Accurate Are Sleep Tracking Rings?
As smart rings are relatively new to the market, intensive testing still hasn’t been carried out regarding their effectiveness and accuracy in tracking sleep. However, individual companies often conduct their own accuracy tests (keep in mind these may display some bias).
The Oura Ring was tested on its ability to measure heart rate and was shown to be over 98.4% accurate most of the time. Compared to a full electrocardiograph conducted at the same time.
Sensors such as those that measure skin temperature are nearly always very accurate; the uncertainty comes in measuring stages of sleep. In other words, in determining when people move from light to deep sleep, which they often do multiple times per night. This measurement is only around 50-60% accurate in most cases. However, even that level of accuracy, in conjunction with other data collected by smart rings, can still offer a valuable picture of one’s sleeping habits.
Would you choose a smart ring over a smartwatch? Let us know in the comments.