Oura faces class action lawsuit over sleep-tracking accuracy claims
A legal challenge alleges the smart ring lacks the necessary sensors to accurately measure neurological sleep stages.
Oura is facing a class action lawsuit alleging the company misled consumers about the accuracy of its smart ring's sleep-tracking capabilities. The legal action, filed by plaintiff Madison Surber, claims the device cannot reliably measure neurological sleep stages.
The lawsuit alleges that Oura rings lack the essential sensors required for accurate sleep staging, specifically those needed to monitor brain waves, eye movement, cardiac activity, and muscle movement. To support these claims, the complaint cites a study published in Nature (s41598-025-93774-z), which found the smart ring had a success rate of only 53% in correctly assessing each sleep stage.
The biometric divide
Most wearable health trackers, including Oura, use biometric signals such as heart rate, body temperature, and respiration to infer which stage of sleep a user is in. Oura has defended its methodology, stating that it stands behind its science, research, and accuracy claims. The company argues that sleep stages are associated with measurable physiological changes that can be captured by its sensors.
However, the plaintiff's complaint argues that this approach is fundamentally flawed, asserting that "sleep happens in the brain, not on one's finger." The core of the dispute rests on whether physiological proxies are a valid substitute for direct neurological data, which typically requires clinical equipment like a polysomnography (PSG) test.
Industry implications
This case carries significant weight beyond a single product. If a court determines that biometric translation from a finger or wrist is fundamentally incapable of accurate sleep staging, it could undermine the value proposition of the broader health wearables market. This would potentially impact other multi-billion dollar players, including Apple and Google, who utilize similar biometric inference models for their sleep-tracking features.
What's next
Oura continues to maintain that its science is sound and its claims are accurate. The court will now determine if the company's marketing of these inferences as reliable science constitutes a misleading practice. It remains to be seen if the 53% success rate cited in the Nature study will be accepted as a definitive benchmark for the device's failure in a legal context.