I have two oxygen monitors...
The black one usually reads higher than the white one... However the white one can transmit info to my cell phone and I can send it to my email as a pdf file...
The black one can't record the info...
I've seen numbers as low as 86 on the black one for oxygen and down in the low 70's on the white one...
Sometimes after walking in the house it takes a long time for my heart rate to settle down... It will stay in the low 100's or 90's.... When I'm feeling better and catch my breath, my heart rate is in the 70's and 80's... When I'm resting after a nap I've seen it in the 60's....
When I'm struggling to breath sometimes I can do a couple hits of my asthma inhaler and it will help... It seems to help also when my breathing is struggling and my heart rate is up, it helps get the heart rate down some, but not always...