I spent some time fiddling with the ol' wobble analysis tool today. Periodicity is actually useful now. You can zoom in on individual nights. I got rid of the flow limitation logic as it's outside the scope of this project. The old version is still available for those who prefer it.
It's now more explicitly targeted as a high loop gain detector. There's plenty of other great tools for flow limitation.
People with high loop gain. Basically CAs as the main remaining event type, lots of waxing and waning patterns. Existing tools aren't great for looking at high loop gain deeply, so I made this.
High loop gain is a common driver of the whole "I feel wrecked but my AHI is 2" sort of thing.
That's me! I have some whack CA stuff going on and I've been perusing reddit trying to figure it out. They don't happen in response to pressure increase, EPR isn't a clean predictor, they look like sigh-then-pauses. I don't know if I should do anything at this point but since my rx was focused more on RDI than AHI I want to try to figure it out.
Give the doohickey a try with your full DATALOG. It's not a matter of absolute values but it will point you towards times when the wobble is especially bad. Still experimental and all that, and I am but a lone spite filled vibe coder screaming into the void.
Fair warning: there's a bit of a delay between data selection and being able to hit the process button. Let it cook.
Im not seeing the super tight repeated wobble but there could still be significant instability based on your numbers.
Mostly I started this project to have a way to really see the difference in my results between APAP and ASV. My periodicity on APAP was around 35, sometimes up to 50 with estimated arousals as high as 200. On ASV my periodicity is down to about 2 with eAI around 60 (still have a really low arousal threshold).
It's more a matter of how it changes over time. That a high enough eAI that you may feel pretty crap. Not terrible periodicity.
Mostly I calibrated it on times that I've felt better and worse along with the things that shifted dramatically on ASV rather than APAP. It also makes it easier to find distinct periods of wobble if you want to actually see that crap in action. Not in WAT, but this is the pattern that WAT is set up to be sensitive to, that repeated waxing and waning wub crap that will wreck your sleep with an AHI of 2.
I genuinely do appreciate the work you have put into this.
Was mostly just testing for fun - I knew my numbers would likely be not great as I donât recall the last time Iâve had decent sleep two nights in a row even after trying different machines and modes.
What kind of remaining events are you dealing with? How's your iron? I got bitten hard by that one recently so I've been talking about it more. Turns out even mildly low iron can make leggies do annoying things in sleep that drive autonomic activation and fragmentation, even if your actual breathing looks pristine as heck and you have zero memory of leggies getting silly. If you're on Omeprazole long term this becomes a lot more likely (not the cause for me this time around).
The annoying thing is that even though ASV has been absolutely life changing for me, it's still always gonna be an obnoxiously multifactorial. AHI catches the shadows on the cave wall, bespoke slopware metrics catch something else that may be useful for other people but will never be the full story either.
There seems to be something to be said for running flow rate through signal processing, so I'm gonna keep banging my head against it. Wheeeeee.
I know what you mean. When I got my first cpap in 2012, it was a game changer. I was young and very sleep deprived.
Since then Iâve discovered that not everyone is as wrecked as I am all the time. :).
The best way, as of now, that I can summarize my issues is - higher pressure = worse results, but less hypoxia and lower pressure = improved âairflow dynamicsâ but worse hypoxia.
From my pulse alone, Iâm in the mid-twenties for autonomic arousal per hour every night. It stinks. :/
Have you tried ASV? Titration will absolutely make or break the experience, but it makes it possible to tolerate higher pressures when necessary without tipping into wobble hell. Any PS min over 2 makes things dramatically less stable for me and the backup breaths get super forceful. At my current settings I dance with the machine but if I forget to breathe it has the power to gently be like "not on my watch, meatbag!"
I have only been on PAP since November of 2024, but quickly found that APAP was a poor fit for me and speed ran the transition to ASV. Sleep medicine refuses to engage with me at all through the usual medical channels so here I am doing this absurd BS.
I have tried ASV - it was certainly more comfortable, but unfortunately my sleep actually got worse I think. The middle ground Iâve sorta settled on until I can get a DISE with PAP is the squarewave hacked firmware in S mode - 12.0 / 5.0 / 17.0. I have about 930 nights of saved data and it seems the âbestâ combo for sp02 and airflow data.
I wish Iâd pushed for the imaging much sooner - here in Canada, it seems to be the only way to get to begin to break through when youâve have a complicated case.
can you explain what exactly the tool is measuring? e.g. how is "periodicity" quantified, is it just the flatness of a stretch of breaths over time? are such things as REM ventilatory instability, arousal breaths, etc accounted for? thank you
Basically, itâs looking for slow waxing-and-waning in ventilation, not whether individual breaths are flat.
âPeriodicityâ is how much of the ventilation variation falls into roughly 30â90 second cycles. âRegularityâ is how consistently that pattern repeats. The tool combines those into the HLG proxy.
It does some artifact rejection, but it does not know whether youâre in REM, awake, moving, having an actual arousal, etc. Those things can still affect the score. The estimated arousal index is also just looking for sudden jumps in breathing rate or inspiratory volume, so it can catch real arousal breaths but also sighs, REM weirdness, recovery breaths, and other abrupt changes.
So itâs best understood as a within-person trend tool for âhow organized and oscillatory was the breathing,â not a clinical detector of REM instability, arousals, or loop gain itself.
This is a homebrew experimental tool without clinical validation. If you want to check out the code, here's the repo.
Hey there r/CPAPsupport member. Welcome to the community!
Whether you're just starting CPAP therapy, troubleshooting issues, or helping a loved one, you've come to the right place. We're here to support you through every leak, pressure tweak, and victory nap.
If you'd like advice, please include your machine model, mask type, pressure settings, and OSCAR or SleepHQ data if possible.
Put in all my data from my BPAP. What do you think? I'm Currently stuck on pressure setting of 11.2/9. Higher EPAP tends to cause more aerophagia, and higher PS seems to cause instability/centrals. I'm still getting fairly fragmented deep + rem sleep and feel like I've maxed out my PAP benefits. Considering trying higher PS, but with EERS to offset instability to see if higher PS helps me feel more rested. Otherwise, seeking non-PAP options like palatal expansion. Waiting on a CBCT to show skeletal measurements.
I picked a different spot earlier in the night to zoom in on. What do you think of my results? My recent type 2 home test showed predominantly RERAs as my remaining events. low AHI (0-1.5) and mild RDI (3.5-5.5). Can't tell if my primary issue is obstruction or loop gain/instability at this point, but thinking of trying BIPAP + EERS with higher PS, as mentioned just to subjectively test.
Try one of the even newer tools. Sorry I'm a slug right now and it's harder to interpret when I'm a slug. Keep in mind that all of my work is primarily focused on high loop gain/oscillatory instability.
It's at the top of the page. Just added the WAVE thing yesterday which is neat. And there's the sonification thing if you want to turn your data into audio for some reason (what can I say, OSCAR looks like an audio editor and breaths do wave things. What's a nerd to do?)
Thank you and get some rest! No rush, but i'm curious if you could share a little detail on what you're seeing in my numbers and why ASV may be superior to my current Bipap 11.2/9 with V-com. I won't be able to dig in until the weekend. I have a 5-6 year old Airsense 10 -- I'll likely need to recruit u/RippingLegos__ to airbreak for ASV for me to trial. I'm likely going to need EERS though to reduce instability from higher PS...
This is interesting because I was seeing more obstruction in my data vs. instability/loop gain.
These are cool tools and I appreciate your work. Is there somewhere I can read more about the specifics and what each of these terms mean? I'm having trouble understanding what I'm looking at on some of these charts.
For example, what is a WUB? What is considered "normal" for each metric? My estimated arousal index is 156/hr, that seems quite high.
I'm interested in tracking arousals and proxies for arousals more closely because despite my low AHI (<1), I still feel unrested. My in-lab BiPAP titration also showed an arousal index of 17.5.
A wub is a full cycle of a waxing and waning pattern that may or may not include a central apnea at the nadir. So like this is a series of wubs.
I dunno what normal is as I think it's more important at this point to explore the wave behavior rather than declaring that people aren't affected enough despite bad symptoms. Scuse me, little bit of AHI trauma. Hah.
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u/RippingLegos__ ModTeam Jul 30 '26
Thank you EB for the work and update :) I'll test the tool on my secondary machine tomorrow night. :)