Gayle, what wonderful news that Gary is feeling better!!!
My MIL had a c-pap when we were at Nebraska that she just started using. Brenda has purchased a little thing that goes on your finger to tell what your oxygen level was. It was a neat little gizmo. She said that she got it for about $100 somewhere. She took it to the hospital and they were amazed with it and that's what they used to check my mil's levels while she was there. You might want to check into getting something like that for home.
I think that this is what my MIL had
http://www.amazon.com/dp/B0030OAUN0/...SIN=B0030OAUN0