Oura ring: Improved accuracy of wearables promises better healthcare for all

The Oura ring's high accuracy in monitoring a person's biomedical signals might enable a prediction of a COVID-19 infection two to three days before symptoms appear.
Written by Tom Foremski, Contributor

It's all about the finger -- it's much better than the wrist for tapping into bio-medical signals, says Oura Health CEO Harpreet Singh Rai. The signals are as much as 10-times stronger from a finger -- but the challenge is the tiny form factor of a ring compared with a wristband.

This is exactly what the Oura ring has managed to achieve with a normal-looking ring that is comfortable to wear -- a key goal for Singh Rai, who understands the value of continuous unobtrusive monitoring in evaluating personal healthcare because everyone is most definitely not the same. This is also a key part of the design philosophy of the Oura ring: The accuracy of the sensors is focused on detecting the minute differences in a person's signals -- because that's a highly personal marker of a person's health -- and not on averages based on a wide range of values.  

The Oura ring is part of a next generation of wearables -- sold at consumer prices with testable claims of matching the performance of medical equipment costing tens of thousands of dollars. 

For example, the latest version of the Apple Watch claims the device "is capable of generating an ECG similar to a single-lead electrocardiogram."

And the recently announced Amazon Halo healthcare app and wristband claims it can measure a person's body mass index as accurately as a doctor can. 

Unusable Data

The problem with the first generations of wearables was that they generated huge amounts of unusable medical data. That's what two doctors told me back in December 2016. (Dark side of wearables: Tsunami of useless medical big data). 

The doctors said that they were trained to interpret EKG data from highly accurate medical equipment that is calibrated and verified. Many patients were sending them data from their wearables; however, the accuracy of this data could not be trusted, which made it useless for medical purposes. 

What is needed, they said, are wearables that can be calibrated and tested to validate the medical quality of the data because only then can that data be trusted and used in large scale studies to potentially improve healthcare outcomes.  

This next generation of wearables claims very high levels of accuracy that are directly comparable with medical grade equipment -- precisely what those doctors said back in 2016 that they needed.  

However, we shouldn't expect quick medical results once highly accurate wearables become available. The doctors pointed out that it will still take several years for studies to be designed and completed, then analyzed, before improved healthcare procedures emerge. 


The electronics of the Oura ring can be seen under a transluscent water-pro

Oura Health

The Oura ring is packed with super-sensitive electronics that includes accelerometers, infrared LEDs, temperature sensors and a gyroscope. According to Oura Health, the ring monitors key characteristics of a user's heartbeat with an accuracy of 99.7% -- essentially equivalent to professional medical equipment.

The two infrared LEDs track blood volume, and the accelerometer and gyroscope track the intensity of movements in three directions, plus three temperature sensors, and a rechargeable battery for seven days of use.

The company tested its accuracy on 49 subjects compared against a medical grade ECG device and found the ring performed at "near -perfect for resting heart rate data", and "extremely high for heart rate variability."

The Oura ring's accuracy caught the attention of medical researchers at the University of California, San Francisco, who have designed a study involving more than 2,000 healthcare workers. Their hypothesis is that biological signals collected by the Oura ring will enable advanced notice of a COVID-19 infection.

UCSF is "studying if the Oura ring can warn its users of a COVID-19 infection as much as three days before the first symptoms show themselves," says Singh Rai. 

Infected healthcare workers could be quarantined well before they start becoming infectious to others and well before their symptoms show themselves. Testing can take several days to produce results; the Oura rings could identify and quarantine users days earlier -- potentially saving lives by removing symptom-less spreaders and resulting in earlier treatment of those who are infected but don't yet know it. 

Early treatment with blood-thinners, for example helps to avoid micro-clots in the body's organs -- one of the symptoms of a severe COVID-19 infection. 

And earlier medical care lessens the need for a ventilator -- a last choice treatment since it causes tremendous physical damage to a patient's respiratory system.

The ring has also attracted the attention of the National Basketball Association which is studying the use of the rings to improve athlete performance and improve healthcare for employees.

The Oura ring has also attracted significant interest from VCs and celebrity investors. It raised $28 million for a Series B in March for a total of $76.5 million.


The company has an interesting history; it originated in Finland and has been honing its finger-focused technology for several years. The current CEO Harpreet Singh Rai used to be a Wall Street analyst and the wearables market was part of his research beat. 

Singh Rai identified Oura as the company with the best wearables strategy and became a big fan. Then one evening, in a bodega in Manhattan, his friend spots someone across the store and says, look there's someone wearing a T-shirt with that company name you are always talking about. Singh Rai introduced himself and that chance encounter led to his CEO position at Oura.


The Oura ring was not created to spot early COVID-19 or any other infections. Its primary use case is to help users get better quality sleep.

Every morning, Oura ring users see a report on how many hours sleep they had, how many minutes in each phase, such as the REM dreaming phase, etc. 

"We know from many studies that the amount and quality of sleep is the key to maintaining good health and so we give users the tools to see what affects their sleep, to see how exercise, meals, how any of their activities help or harm their sleep, which in turn directly impacts their health," said Singh Rai.

The Oura ring collects data 24/7 (except for a weekly one-hour recharge), which means there are many opportunities for users to test their behaviors against outcome, and to uncover insights into their personal nature that improve the quality of their sleep.

Oura makes sure that privacy is protected and that the users are in control of their own data and how they want to apply it. 

The ring is unobtrusive and it won't buzz people for not getting enough sleep but it will signal if it is not a good time to attempt certain activities because of poor sleep quality. Conversely, its software will signal when the body is rested and in good shape to engage in energetic activities. The National Basketball Association bought 2,000 Oura rings to test the performance of its athletes compared with their sleep score -- it could lead to who gets to play or gets time on the bench. 


It is common to find startups trying to establish their platform as the dominant one. Singh Rai's strategy is to cooperate with everyone, to be compatible with many other consumer wellness devices such as the Apple Watch. But also allow the user access to their own health data to use and analyze in any way they want. 



Highly accurate devices are essential or a personal wellness revolution where consumer priced devices provide medical-grade performance. And it is happening: There's a growing list of inexpensive medical hardware that constantly improves in accuracy: oximeters, blood sugar monitors, blood-pressure testers, ketone breath analyzers, and more. All are available in a well-stocked neighborhood pharmacy at affordable prices.

However, taking responsibility for personal wellness requires much more than buying medical grade wearables. 

Having the same stethoscope as a doctor means nothing. But having access to the knowledge of hundreds of thousands of doctors thanks to machine learning; and based on accurate medical data harvested from millions of people is where personal healthcare enters a new era for everyone. And prevention is where technology can begin to turn around the massive inflation in healthcare costs. 

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