At-home study

[Pugsy]

That's an ugly hour for sure but the rest of the night isn't bad at all at least on paper.

2 maybe ideas come to my mind...

The machine increased the pressure a LOT that second half of that hour....Flow limitations were unremarkable so I doubt it was that.
You did have a lot of OAs and likely the machine wanted to kill them. We don't normally see REM that soon after going back to sleep but I suppose it wouldn't be impossible and the other reason for such dramatic changes in pressure is when we have ended up on our back....often people need more pressure when they are on their back because supine sleeping can cause OSA to worsen.
The machine wanted to increase the pressure to kill the OAs but the more pressure caused the centrals.

or...

you weren't even sound asleep even though you think you were asleep and all that ugliness is SWJ sleep/wake/junk arousal related breathing.
See the videos here that show how to zoom in even closer to help figure out if the flow rate is showing asleep breathing or arousal breathing.
http://freecpapadvice.com/sleepyhead-free-software

[OnTheCouch]

Were you on your back that second part of that 1 hour segment above?

Probably. I've always slept on my back, although I've been trying to sleep on my side just to change things up, since I've been having so much trouble lately. Even when I go to sleep on my side, though, I wake up on my back.

[palerider]

Another member uses Anti-Bacterial Filters to help with his allergies.

Interesting - I have some that I bought a while back, but they didn't work with my old machine so I put them on a shelf and forgot about them. I'll have to dig them out and give them a try.

Thanks so much for the suggestion!

How can they "not work"? they fit in the hose, and I'm still using them. They catch stuff that gets past the hypoallergenic filter.

[OnTheCouch]

How can they "not work"? they fit in the hose, and I'm still using them. They catch stuff that gets past the hypoallergenic filter.

,
This is a picture of the humidifier. Note the arrow pointing to the hose outlet. Now imagine a cube siting on top of this thing, within the recessed area. The bulbous filter is too big to fit on that hose outlet when the body of the machine is in the way.