I have one more test coming up on December 3rd -- an overnight sleep apnea test. For the last two weeks I have kept a journal of my pulse and oxygen levels. Take the readings at various times -- even when I awaken at night. Other than the last two nights when I inched the oxygen level up a bit. I was wearing the oxygen with no impact on my levels for a week and a half. I was consistently between 90 and 95. Since I inched up a half measure from the level one, my readings have gone up to between 95 and 98. I still fight lethargy and what I call fuzzy headedness.