Screwy pressure graph

During a nice nap with my new Sleepweaver Advance mask, I got this very unfamiliar-looking pressure graph. I've never seen it straight-line like that before. There are usually pressure blips regularly spaced if there are no events during a time period. Is this an OK graph?

BTW, after that perfect period of sleep in the beginning, after about 23:00, I was sleeping/awake and fiddling with the mask thinking it was leaking. Luckily, I've been able to figure out that when my respiration drops like that, I'm awake or semi-awake. Several apps, including ZEO, have helped in that process. Makes it great to figure out funky event flags.

As far as the mask, it's like an illusory mask! How can a piece of cloth work like this? It's fabulous, especially for a side sleeper who turns a few times a night. Nice low leak rates (mostly), even with smooshing my face into the pillow. The headgear is kind of homemade-looking, but works, so no complaints. In fact, it gives me some ideas on custom-making some headgear for other masks.

That's weird....it looks like your pressure went down and stayed down until the end of the nap.

I don't know if this is a SleepyHead fluke or a machine fluke. Do you have Encore to verify what SH is showing?
While it wouldn't be impossible to not have those pressure probe spikes you are used to seeing...man, that's a weird looking graph.
Which SleepyHead version are you using?

I'm using the latest beta version of Sleepyhead. Yeah, it sure is weird. Looks like it's running in CPAP mode except for that bit in the beginning and at the end. Never seen a trace like that in the four months I've been using this.

That initial drop is something I noticed happens when you use the Mask Fit feature. I had just learned about it and since I had a new mask, I thought I'd try it. I guess that how it looks when it transitions from the fitting to actual therapy. It showed up just like that in the previous night's output with Mask Fit also. Here's that one. I rolled over and checked the time about 3:30 for the lovely "noise" until I fell asleep again.

Ah...so that's what the mask fit feature does to the graphs.

I wouldn't worry about anything then. The lack of the pressure probes during a 2 hour nap isn't a big deal.
When I was using APAP I have seen longer periods of time without pressure probes. I don't know why and while not common...not all that rare either.

Now if you start getting entire nights with out any pressure probes and you are for sure in apap mode and not the mode where it switches you back to cpap fixed....maybe a talk to the DME would be in order.

BTW, I verified the pressure graph in Encore Basic. Appears to agree:

Pugsy wrote: Now if you start getting entire nights with out any pressure probes and you are for sure in apap mode and not the mode where it switches you back to cpap fixed....

Are you saying there's a mode where it automatically switches from apap into cpap fixed, or did I misunderstand you?

Yes...it might be the Opti Start mode. I forget exactly. It does apap for a period of time and evaluates things and then switches to fixed cpap on its own and periodically evaluates things in apap mode briefly but main pressure delivery is still fixed.
Just make sure that in the clinical menu it is "auto" and it will always be apap full time.

I just picked up a 560 for a friend and I think I saw Opti Start in the menu choices. When I was on apap I had the 550 and it didn't have that extra mode so I don't have personal experience with it.
I was just doing a quick run through with this new machine so I didn't look real close and I don't remember exactly how Opti Start works. I could be wrong with my memory of it...and if I am I will let you know. I need to get the 560 manual and read up on it but don't have the time at the moment.