The WatchPAT is a simple Pulse Oximetry device with an added sensor for airway movement. And the WatchPAT makers, like most biomedical device makers, say the science behind the device is impeccable. Well, re: pulse oximetry, that's true. Go to the Wikipedia site for pulse oximetry. It's now a standard, reliable component of medicine. Most pulse ox is immediate only. A major value of the WathPAT is giving you a recorded sleep episode showing pulse ox the entire time. My O2 sat, or blood saturation of oxygen, was great the entire night.

How about the sleep apnea sensor? I had some problems there. By one measure, I had an index of 8. By another, I had an apnea index of 23. The difference was a very high number of very short apnea ( less than 10 seconds). I actually interpret this as a probable improvement. This is due to the Invisalign braces I've used for 6 months. I can feel my teeth spread out and my tongue moving out of my airway and into my mouth.

There is a final component of the readout. It says I have REM ( rapid eye movement) sleep 1.5% of the time. I am very skeptical of the value of the REM sleep value from the Itamar WatchPAT.