Accuracy of sleep data

Update on posts relating to ScanWatch sleep data being inaccurate.  

Last night I had a sleep study done at our local hospital; the study was conducted by a certified technician and monitored by a sleep physician.  They allowed me to keep my ScanWatch on to compare accuracy.  The results showed the ScanWatch to be highly inaccurate, e.g. Stage 2 (light sleep) as shown by the sleep study was indicated on my ScanWatch as Deep + REM sleep, and so on.  Only fifteen minutes of the entire night did the ScanWatch come close to matching the sleep study results.

(The pulse oximeter readings also display as "normal" at the same moment that the nurse's oximeter reads 88%.  The ECG will also not function if the pulse rate is greater than 100, which is one of the most important times an ECG is needed.)

I purchased this ScanWatch in October of 2022.  It is now January, 2024.  I do not recommend this ScanWatch to be used as anything other than a highly overpriced time piece.