Lifewire: One study found that the Fitbit Ionic and the Oura Smart Ring got the highest marks for accuracy.
The most accurate way to measure sleep is in a laboratory using special equipment. But scientists recently published a study in the journal Sleep, which found that several devices, including one by Fitbit, nearly equaled professional monitoring devices. Another study published in Nature & Science of Sleep found that the Fitbit Ionic and the Oura Smart Ring got the highest marks for accuracy. Independent experts say they aren’t surprised by these findings.
lifewire.com
