Two of my sons use a CPAP and a BPAP. They go annually for testing to make sure a. they are getting enough oxygen b. Are they on the right machine. One machine pumps air into your chest and if you wake up with your chest feeling tight, you need to have it checked. The other machine allows you to breathe naturally but if you miss a breathe it responds with air and stirs you to breathe again. This is what my son says. He would have died with out this machine after his heart surgery. Take care and soon you will be sleeping like a baby.