I have had sleep apnea for serveral years. I was given a Bi-pap machine instead of normal c-pap machine. It has the capability of adding oxygen to it. This sorry to say happened 4 days ago. I now have the oxygen hooked up to it and to myself through out the day. It took a while to get used to the machine several years ago then I would use sometimes and sometimes not. when I would use it I could see the difference I didn't hurt as much could function during the day generally felt better considering everything else that is the matter with. when I got sick to the point of hospitalization last week I was sent home with oxygen to include the bi-pap. The last few nights have been really pleasant ones. I have slept thru the night and I don't feel like I am choking. Good luck on your machine and hope everything works out for you.