We’ve talked a lot about smart devices—dashcams, smart doorbells, and similar—and how your personal data interacts with the law.
But in August, 2026, a lawsuit was filed against the manufacturer of the Oura ring, a smart ring that tracks your sleep, heart rate, activity, and overall health.
If you wear an Oura ring and trust the sleep score it provides each morning, this lawsuit might be worth your notice. There are two prongs to this lawsuit that could affect you: (1) as a consumer who spent money on a device that might not function as you expected; and (2) as a person whose wearable device data might end up in a courtroom if you’re ever involved in personal injury litigation.
The Oura ring lawsuit
California resident Madison Surber filed a proposed class action lawsuit against Oura Inc. and Oura Health OY in the U.S. District Court for the Northern District of California (Surber v. Oura Inc. et. al., No. 3:260-cv-08686). The complaint specifies two important statistics Oura sets forth in its marketing:
💤 “95% Sleep Staging Accuracy Compared to clinical sleep lab” (on Ring 5 product page)
💤 “79% agreement with gold-standard polysomnography” (from a 2022 company blog post)
There was also marketing language that included “Built for accuracy” and “Unparalleled accuracy.”
The lawsuit pleads seven counts:
- Fraud by misrepresentation
- Unjust enrichment
- Violations of California’s Unfair Competition Law
- Violations of California’s False Advertising Law
- Violations of California’s Consumers Legal Remedies Act
- Breach of express warranty (Cal. Com. Code § 2313)
- Implied warranty under the Song-Beverly Act
The proposed class (group of people eligible to join the lawsuit) as U.S. purchasers of the Ring 5, Ring 4, and Ring 4 Ceramic. The California subclass reaches back four years, and pleads an amount in controversy at higher than $5 million.
What does the science say?
The complaint’s argument focuses on the ring’s hardware. Clinical sleep staging (or polysomnography) reads brain waves (EEG), eye movement (EOG), muscle tone (EMG), and cardiac electrical activity (ECG). The Oura Ring does not have any of these sensors. It contains red and infrared LEDs, green and infrared LEDs, a digital temperature sensor, and an accelerometer. The plaintiff alleges that those peripheral signs infer your sleep stages using an AI model—she says it’s “guesswork” that’s no more accurate than flipping a coin.
The lawsuit cites published research that includes a March 2025 Nature study that reports 53% overall stage-classification accuracy across 45 nights, with REM sleep overestimated by about 31 minutes per night. Research by the University of Massachusetts in Sleep Advances indicated that there was meaningful divergence from polysomnography, especially in older adults.
Oura’s defense
Oura denies the allegations.
A spokesperson said the company “stands behind our science, research, and accuracy claims.” They note that sleep stages produce distinct, measurable physiological changes, the algorithm was trained on more than 1,200 nights of data, and its staging was validated against polysomnography in peer-reviewed work. Oura also emphasizes that the ring is a wellness product, not a medical device and not a substitute for a clinical sleep study. Nothing has been proven; currently, the lawsuit is in the pleading stage, so these are solely allegations.
Personal injury lawsuits and the Oura Ring
Wearable data increasingly appears as evidence in injury cases, and it cuts both ways.
If you were injured in a car accident, a slip and fall incident, or some other type of accident, you might be able to make a claim for sleep disruption, insomnia, chronic pain, or the sleep effects of a traumatic brain injury. Your ring’s nightly output is discoverable if anything in your claim relates to your sleep, or related physical well-being.
Defense counsel and insurers request exports from wearable devices to argue that the plaintiff slept sufficiently. Plaintiffs often offer the data affirmatively to corroborate facts that they can’t prove by other means.
The Surber complaint gives both sides a reason for caution. If a device that lacks EEG, EOG and EMG sensors is producing modeled estimates rather than measurements, this is a serious foundation and reliability problem for anyone trying to put those numbers in front of a jury—this is a serious argument against an insurer trying to use them to discount your damages. A plaintiff can’t assume a ring helps their case, but they also should not assume it would hurt them.
Practical steps related to an Oura Ring if you’re injured
If you have an active injury claim, do not delete your Oura account, wipe the app, or reset the ring.
Taking these steps can raise spoliation issues. In other words, if it’s discovered that you destroyed potential evidence from your Oura ring, a jury could be instructed that they should assume that any destroyed or deleted evidence would have been harmful to your case (the assumption being that you wouldn’t have deleted it otherwise).
Instead, export your history and send it to your lawyer. Keep your purchase records, order confirmations, and screenshots of marketing you saw prior to purchasing the device. These documents matter for class membership if the case proceeds. You do not need to file anything to be part of a class action; if a class is certified, you will receive notice.
If your sleep problems are genuinely affecting your recovery, get a clinical sleep evaluation. A physician’s diagnosis carries far more evidentiary weight than a consumer wearable ever could.
If you have an open claim, or if you are expecting to file a lawsuit, let your lawyer know you own an Oura ring. They will advise you on how it might affect your case.