Reading SleepyHead Data: When Am I Sleeping?

[Oddprofessor]

Hi everyone.

I can't seem to tear myself away from the SleepyHead data. (We and our inner workings are infinitely interesting... to ourselves.)

One thing that I felt was very useful about my sleep study data was the information about when I was asleep and when I was awake. I realize that the telemetry in a sleep lab is different from that of the CPAP machine, so without the EEG data there is no way for the CPAP machine to know, but I wondered if, as a rough rule of thumb, I can assume that I was asleep during the periods when there was least variation in my respiratory rate. I remember the respiration data from the sleep study seemed very regular while I was sleeping without apnea events, so I'm guessing that the variability measure would result in more or less a flat line on the graph when I'm sleeping. Right or wrong?

Also, I think I'm getting the hang of side-sleeping without making the mask leak. And I have found, after experimentation, that the over-the-head hose placement is MUCH more comfortable for me than trying to sleep elephant-fashion. Every day, you learn a little more.

[Pugsy]

Flat line normally means no air flow or greatly reduced air flow and that is usually a result of some sort of apnea event.
Can you post an image of what you are looking at so that we can see what you are seeing?
How to post images discussed here.
viewtopic.php?f=1&t=81072&p=737779#p737779

[Oddprofessor]

OK, I chose a chunk of time that shows no apnea events until the end. As you can see, respiratory rate is pretty flat (no large deviation, which is what I would expect if the rate of breathing was steady with little variation), until the end when the events start popping up and the resp. the rate starts fluctuating. No leaks during the calm, a little one at the end.

[Pugsy]

Got it.
I don't know how much we can accurately infer from respiratory rate but I see what you mean. When we look at the various graphs long enough we do sometimes see a pattern develop that we could very likely associate with being asleep or awake or sometimes even in REM sleep.
If you know that you wake often you may be able to see a pattern develop if you can for sure isolate the awake times.
Normally our asleep breathing is much more stable and boring when compared to awake breathing but not all activity with respiration means we were awake...might have been a good/bad dream too. With time and lots of looking at the graphs you probably will see a pattern develop.

I just picked this one from the other night. Zoomed in on the time frame around 1:00 AM...prior to it the respiration rate looks pretty boring but after that one OA and a little snore..it's more active. Now this also could be REM stage sleep around this time where the Resp Rate is more active. Or maybe I was on my back. I am pretty sure I was asleep but I can't swear that there wasn't a minor arousal in there where the RR is more active because we don't necessarily remember arousals every time we have one.
My OSA is documented much more severe in REM stage sleep and I often see a bit of activity in that 60 to 90 minute post sleep onset which is where we normally see the first REM stage sleep.

[Sir NoddinOff]

See if this helps:

viewtopic/t93914/viewtopic.php?f=1&t=93 ... me#p859473

This method won't show sleep stages but it's pretty helpful for an overall picture. As Pugsy said: REM usually starts for most people about 60-90 minutes after actually falling asleep. You can expect to see some flow spikes around that period.

[SleepyCPAP]

Hi Oddprofessor,

I'm glad you are finding ways to adjust your sleeping position and hose. The machine only does so much... we get to adjust the rest for our comfort and good rest.

I find the expiration time graph on Sleepyhead to be a better indicator of when I'm awake. I see my time go over 2 on the graph when I am not yet asleep or when I'm waking up. Some of the occasional spikes on that graph turn out to correspond to wave flow patterns near RERA or other potential short awakenings.

--SleepyCPAP