Hi @jpaul, I too have trouble staying asleep. I was diagnosed with OSA. After the third sleep lab,was diagnosed with both OSA and central apnea. I was having so many apneas every night and was constantly fighting the masks all night long. Now after the fourth sleep lab the doctor has said that the bipap can sometimes make the centeral apneas worse. Now I am oxygen only at night. I too sleep about 2-3 hrs get up for a bathroom break and try to go back to sleep. I have other issues also. I am lucky if I get 4-5 hrs sleep a night. I have only been on the oxygen for about 2 weeks. Now that there is no record of my sleep pattern, I am wondering if the oxygen is taking care of the problem? Our son died of sleep apnea. I can't help by wonder if this is helping. I am still so tired, but can't sleep more that a couple hours at one time. Maybe someone can answer my question. Thanks for your idea on 2 phase sleep pattern. You mentioned a Tracker?? What is this? & where can I get it?