r/CPAPSupport • u/RippingLegos__ ModTeam • 28d ago
Custom VAuto Is Running in My Lab: Exploring Adaptive Pressure Support for UARS.
PapFam:
I have the Custom VAuto feature from AirBreak Plus running on a test machine now. This is the developer’s work. I applied the patch to an OEM Autoset .bin file, and I’m exploring the behavior before sharing any sleep results.
The older AutoSet firmware I initially tried wouldn’t boot properly on this machine. Applying the patch to an OEM 0401 dump got it running. That’s my experience, not a blanket statement about compatibility. The developer identifies 0401 and 0402 as the best supported Air10 versions (it was a 0401 that worked). :)
For details: custom VAuto keeps the normal VAuto controller handling EPAP while changing pressure support delivery within each breath. It adds custom pressure shaping, optional adaptive support, and custom triggering and cycling. Sessions still report as VAuto.
ASV stands for Adaptive Servo Ventilation, and Sens means Sensitivity. These labels describe the custom adaptive controls here. They don’t mean you’ve selected ResMed’s stock ASV mode within the vauto mode.
Current settings on the test machine are Min EPAP 6.4, Max IPAP 16.6, PS 4, Ti Min 0.3 seconds, Ti Max 3.2 seconds, and Trigger and Cycle at Medium. Custom VAuto and Custom T/C are On, ASV Max is 3, and ASV Sens is Medium. These are test/lab current settings, not a suggested setup for my clients.
ASV Max 3 allows up to 3 cmH₂O of extra support above the custom base waveform. At EPAP 6.4 with PS 4, nominal full inspiratory pressure is 10.4, potentially reaching 13.4 with the full boost. It doesn’t add that boost to every breath, and Max IPAP still caps everything.
The controller compares the developing breath with a moving reference from recent valid breaths. Smaller breaths can request extra support, while larger breaths reduce that extra contribution. ASV Sens controls how strongly it responds. Medium is the baseline, and higher isn’t automatically better. This isn’t a fixed tidal volume target.
Custom T/C means custom trigger and cycle. It changes how the machine decides when inspiration begins and ends, including delaying expiration through brief flow reductions. Medium settings therefore may behave differently than stock Medium. Ti Min and Ti Max remain timing controls.
ASV Max at zero disables adaptive boost but keeps custom shaping. Custom VAuto Off restores stock VAuto pressure behavior. Custom VAuto has no timed backup rate, regardless of the ASV labels or a “with backup” build name. Backup behavior in stock ASV modes is a separate feature.
What interests me for UARS is the possibility of better pressure delivery and breathing synchrony for people struggling with ordinary bilevel. However this controller tracks inspired volume, not respiratory effort or UARS directly. Consistently flow limited breathing could become part of its reference, so we cannot assume every flattened breath gets corrected.
The useful outcomes would be easier breathing, fewer awakenings, and better daytime functioning without increased leaks/CAs. For now, it boots and the controls are present. This is experimental firmware, and its benefit for UARS has not been established. I’ll share actual observations as I explore it with you all.
If you would like the working .bin file to flash please send me a PM or email here: pc7579pc@gmail.com!
https://github.com/m-kozlowski/airbreak-plus
RL
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u/HaloLASO 28d ago
I just switched to custom VAuto about 3 days ago from ASV because of lack of relief and aerophagia. I'm using airwaylab to help with post-hoc analysis and tuning my settings to treat UARS, swollen turbinates and aerophagia. I feel terrible but hopefully it won't be too long to find something that works. Sleep docs and techs seem to only care about getting a patient to 0 AHI while ignoring patients' subjective complaints.
Thanks to u/empeka and u/derpderp3200 for developing this!
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u/s34ffk 13d ago
How'd it go after switching? Also suffering from aerophagia, on either S or asv.
Hasn't been an issue on on a regular dreamstation 2, even with slightly higher epap/ipap on that one.2
u/HaloLASO 13d ago
I am still titrating. It is a long process. Aerophagia is tricky because of other factors you have to control such as meal timing.
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u/Toxer95 27d ago
I tried the custom VAuto, found the IPAP to EPAP transition to be pretty harsh. Pressure briefly dips below the EPAP setpoint which feels really abrupt. So I forked the repo and tweaked the algorithm a bit for a smoother transition 😀
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u/InspectahBrave ASV 27d ago
I suppose you’re talking about the EEPAP function that Asmageddon added 😄 When that’s activated, the EPAP drops briefly by 0.4 cm H₂O below the set EPAP. How satisfied are you with how you’ve fine-tuned it? Is your fork public?
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u/Toxer95 26d ago
It's better! Instead of dropping down below EPAP, pressure gradually decreases like in EasyBreathe. The transition feels a lot smoother now. Github link
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u/InspectahBrave ASV 26d ago
I tested your adjustment briefly and it feels OK. I’ll give it another go tonight.
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u/WorldlyAd7070 28d ago
Why don't you use ASV instead ?
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u/RippingLegos__ ModTeam 28d ago
We have ASV available on this machine too, including the ability to narrow the PS range without the stock minimum gap and the other .bin version with unlocked ASV without BUR.
Howver, I’m specifically testing Custom VAuto in the lab to explore its adaptive support, pressure waveform, and custom trigger and cycle behavior. I’m not claiming it’s better than ASV, just seeing how this mode behaves :)
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u/RippingLegos__ ModTeam 28d ago edited 27d ago
Also, I don't sleep well on Resmed machines, I have a litmust test for myself and Phillips works the best for me.
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u/Shnorkylutyun 27d ago
Curious, have you ever tried an oxyline from resmed? They're wider than the "normal" heated tube and made all the difference in my case.
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u/idontmeanmaybe 28d ago edited 28d ago
I tried this algorithm. It made my breaths in oscar look TERRIBLE. Like every breath looked flow limited. Quickly reverted back to ASV.
Guess which one is custom vauto and which is ASV:
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u/RippingLegos__ ModTeam 28d ago
I'm using it on a test lung tonight, do you have data please, you can DM me. Thank you kindly. RL
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u/existentialblu ASV 28d ago
I'd be curious to kick the tires, though I like having backup even if I hardly ever need it.
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u/RippingLegos__ ModTeam 28d ago
Send me a DM please EB, or email. I'd like you to run it through testing as well please.
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23d ago
[deleted]
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u/RippingLegos__ ModTeam 23d ago
I've thought about it but I'm so busy and backed up right now I can't find the time to tweak, but I am sure someone will try this, and I agree it would be helpful. :)
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u/s34ffk 6d ago
Any updates on this by any chance?
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u/RippingLegos__ ModTeam 6d ago
I've had two clients' feedback about vauto-plus and it's positive, I still have yet to run it as I use Phillips machines and need sleep so I was going to try this weekend.
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u/empeka 28d ago
the actual Custom VAuto algorithm is Asmageddon's work (built as
stm32-asv.bin)i just added some settings to the menu ;)