* [[Oura Ring]], a finger-worn tracker which according to a study done by the company shows a 96% accuracy for sleep/wake prediction and 79% for detecting different sleep stages<ref>https://www.mdpi.com/1424-8220/21/13/4302/htm</ref> | * [[Oura Ring]], a finger-worn tracker which according to a study done by the company shows a 96% accuracy for sleep/wake prediction and 79% for detecting different sleep stages<ref>https://www.mdpi.com/1424-8220/21/13/4302/htm</ref> |