SO2 fluctuating wildly

I purchased a CMS60C pulse oximeter to measure my SO2 levels while sleeping. While testing the unit I noticed that my levels are fluctuating all over the place. Anywhere from about 87 to 95 and doesn't stay on one measurement for any length of time. This is while I am sitting perfectly still and not moving. Thinking the unit may be defective, I tried the unit on my wife and it was stable at 98, no wild fluctuations. Anyone have any ideas as to why my SO2 levels would change so dramatically? I am concerned that if my levels are truly dropping to 87 while awake, I am going to see lower levels while asleep.

Over what period of time are we talking. Without that information it is hard to know if it is a problem with the unit or not. Have you tried different fingers? Little Finger or Ring finger are the ones that are preferred if I remember correctly.

You need to allow the device to settle in for 10-15 seconds after first applying it. After that my O2Sat can read from 90-97. It just depends on if I remember to breath deeply or not. BTW a recent study that a friend on CPAP told me about indicates that CPAP users often have desats while reading email. Can't find it on the web but I can see that happening, you get caught up in reading and don't breathe as deeply.

regards
John