Hello Ravenclaw. I think maybe I can help. yes Annie is correct you need a pulminoligist.. but with that said, I have a Bipap and an oxygen concentrator.

I have because of the MG, random sleep apnea and like you during any given day my breathing can be weak.

I have a Bipap which is different than a cpap in that it has a high and low pressure setting that can be adjusted appropriately for each individusl based on levels needed to expel co2 and assist in expanding lungs/diaphragm thus strengthening. there is also a timer so they can gradually climb to the peak/ideal setting.

Now my oxygen concentrator produces pure oxygen which is than pumped into my bipap at the rate evaluated, mine happens to be 3 lpm, I hear the average is two, my docs claim they want my O2 to stay above 90% so this is what is required.

setting the bipap can be tricky even if you know what it should be set at.
My prescription calls for the specific settings night and day as needed.

I have, about once a month, oxygen level tests which are monitored with what looks like a wrist watch, this evaluates your nec o2 levels needed by concentrator.

Hope this helps.
Dan