Oura says its ring can allow users to check in-depth data on a smartphone app that includes heart rate, sleep detection and interruption, temperature and other features like fertility insights and period tracking. Most typically, its rings are used for sleep tracking, with its app providing a “sleep score” that tracks REM and deep sleep.

Rebecca Robbins, a sleep scientist at Brigham Women’s Hospital and assistant professor at Harvard Medical School, and who advises Oura, says the data the ring gathers has the “highest sensitivity for deep sleep detection” compared to rival gadgets, second only to “gold standard” lab equipment, according to a study published in the journal Sensors.

The technology can be a “powerful motivator for health behaviour change”, such as encouraging people to avoid alcohol or smartphone screens before bed, she adds.

Features like this will appeal to fitness fanatics or the health conscious, but Oura says its rings can go further, acting to provide preventative health insights that could alert people if they are getting sick.

A study funded by Oura found that its ring was able to pick up potential symptoms of Covid-19 up to two days before a confirmed infection. Its latest rings can also track cardiovascular age and cardio capacity, which the company says can provide “valuable data for patient care, clinical assessments and research studies”, as well as sports teams and athletes.

The company has not escaped the hype around artificial intelligence (AI), adding a new digital assistant – Oura Adviser – that will provide healthy-living tips to users based on their readings in its app.