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+--- Thread: Why don't these flow rate curves count as flow-limited? (/Thread-Why-don-t-these-flow-rate-curves-count-as-flow-limited)
RE: Why don't these flow rate curves count as flow-limited? - cathyf - 09-26-2021
Ok -- one thing that I can see is that this has nothing to do with EPR/PS. This first appeared in my data in Spring 2016, it's long periods of most nights. I had EPR off until Spring 2021, which is when you guys explained EPR to me! (Have I said "thank you" for that recently?)
Here is four minutes on April 8, 2016:
https://www.dropbox.com/s/6u63rwic2xt813l/20160408.png?dl=0
Sheer chaos! My little autoset is quite the trooper trying to figure out what's going on, LOL. (I left the leak rate graph off to save room -- but there are absolutely no leaks detected throughout this entire 4-minute span.) This was me in my very first mask, a size small F10 that had a lot of months on it. This pattern persists through the next 5-1/2 years of autoset use. EPR mostly off. Mask F10, Amara View, Dreamwear FFM, F30, with some attempts at P30i, N30i, Dreamwear nasal. New mask, old mask, everything in between.
I suppose my next experiment is to see what my vauto does with PS set to zero. Does it still keep this at bay?
RE: Why don't these flow rate curves count as flow-limited? - Geer1 - 09-26-2021
I think you have it backwards. Sure you have proven that this asynchronous breathing isn't caused by the trigger sensitivity and EPR/PS transition but you have also proven that EPR and PS have an obvious effect.
That seems clear to me because it sounds like you had this issue more frequently when not using EPR than when using higher EPR and now higher PS. It also is supported by the multiple other members that have treated this issue by using higher EPR or PS on a vauto. My theory about the trigger sensitivity was based solely on your claims that EPR of 3 isn't sufficient but PS of 3 is.
This is probably asynchronous breathing caused by excessive respiratory effort due to restricted/blocked airways. If you really want to prove it to yourself you can try PS of 0 and almost certainly this will come back. Based on everything learned in this thread you should be using a higher PS though instead of playing around with low PS and your autoset...
Edit: You are correct EPR/PS has nothing to do with what causes this. EPR and PS clearly can and do correct it though.
RE: Why don't these flow rate curves count as flow-limited? - cathyf - 09-27-2021
I'm just not seeing EPR3 as better than EPR0 for this particular thing.
Here's April 8, 2016 -- no EPR
https://www.dropbox.com/s/ygttaq7rdnr06zl/20160408EPR0.png?dl=0
here's a closeup of one of those periods
https://www.dropbox.com/s/xg1tb0t4dhcu62f/EPR0.png?dl=0
And September 15, 2021 -- EPR of 3
https://www.dropbox.com/s/pkr1u2bg3rcec1i/20210915EPR3.png?dl=0
here's a closeup
https://www.dropbox.com/s/lxvo3npgpaqogo1/EPR3.png?dl=0
vauto with PS of 3:
https://www.dropbox.com/s/m4z57k2mnlt9bak/20210721_PS3.png?dl=0
I'm just puzzled as to how the vauto prevents this while the autoset on EPR 3 doesn't...
RE: Why don't these flow rate curves count as flow-limited? - kappa - 09-27-2021
The amplitude of the cardiogenic oscillation (assuming that's what it is - the frequency seems about right) seems much smaller in the Vauto trace compared to the Autoset. It's possible that they've put some sort of software filter on the flow signal to reduce that >~0.6Hz noise and avoid spurious PS triggers (beyond the various trigger threshold settings)
RE: Why don't these flow rate curves count as flow-limited? - cathyf - 09-27-2021
This is the vauto on "boring" cardiogenic exhale-ends:
https://www.dropbox.com/s/yv3x42bso19xvwe/vautoCardiogenic.png?dl=0
and the autoset:
https://www.dropbox.com/s/vmo9gzy99t3sh77/autosetCardiogenic.png?dl=0
both seem like they have code to ignore the simple exhale-end phenomenon that seems to be pretty common.
I wish that I had a feel for how common the wild gyrations in the inhale curve shape are -- 2SleepBetta & elliotg are the two others besides geer1 that have shown pictures. Do I understand correctly geer1 that this is something rare in your data? While I haven't taken a careful count, my impression is that I might be spending 10-20% of my time asleep breathing like this.
One of the Science Direct articles about managing TAA in premature infants looked like it might have pictures of flow rate curves in the full article. I'm going to check with our reference librarian to see if there is some way that I can get access to the full article from our institutional account...
RE: Why don't these flow rate curves count as flow-limited? - 2SleepBetta - 09-27-2021
(09-27-2021, 07:48 AM)cathyf Wrote: I wish that I had a feel for how common the wild gyrations in the inhale curve shape are -- 2SleepBetta & elliotg are the two others besides geer1 that have shown pictures. Do I understand correctly geer1 that this is something rare in your data? While I haven't taken a careful count, my impression is that I might be spending 10-20% of my time asleep breathing like this
Digging back more after trespassing your thread with my post, I see many long and short Autoset episodes, long forgotten "TAA"--but those (longer runs anyway) eventually disappeared. I think Geer may correctly see cardio-ballistic artifacts (CBA?) leading Autosets astray. I have other examples of transitions into TAA, to post if those would help understanding here.
Quick looks back saw mask pressure seeming to rise at I-start and peak at I-end relative to the largest (if earliest) TV-like I-wavelet. It may be that two wave forms, still often seen (most often in isolation many seconds if not minutes apart), could witness TAA tendencies the VAuto quashes--though I'd be surprised if one of them, the FR's regular lop-eared rabbit heads (sighs?), at 10-15 second intervals are TAA.
Once you and Geer have worked through this and you two help me understand it all better, I'll consider tweaking Ti and/or Trigger if association of CBA seems strong enough--assuming it invites AI confusion.
My dismissive earlier quip was premature (as if to say "no worries", OUR TAAs are a machine fault not pathological breathing). In my case not necessarily so, but why worry and I don't, though . I mention this only because it is backdrop for my TAA, explanatory or not. It would be interesting to know if the AB-known cases had neurological bases in common.
In the little I've read about TAA, brain stem and other neurological anomalies or injuries were often relevant. Later, duh! I have CMT and had a brother with MS whose granddaughter has MS--no other known (genetic) neurological eruptions in either side of my family two generations back. Before my first angiography my cardiologist sent me to a (new to me neuro MD after mine and my brother's had retired) when I asked about real CMT related breathing risks under anesthetics. He, an associate of my MD's wife's neurologist, was one of those (my only) professional disasters. He was grossly insulted I had gall to consult Mayo's site and to ask if I might have Arnold-Chiari malformation, given some weird recent symptoms (a then-new one that persists, ballistic tinnitus-- better to have mine than louder ones while still or in motion).
Preternaturally curious about causes and patterns, even more so now about TAA's, it's good to see and learn from your probing and overcoming a tough congenital case, Cathy. You must enjoy a strong constitution to survive your sleep challenges given the damage SDB does. You and Geer push selves, sleep practitioners, machines and research to deep rip insurance indurated sleep care grounds for all AB members' dendritic minds and their better sleep. And, yes, use of either "TAA" or "DIA" (diaphragmatic intercostal asynchrony, adjectively conveying "apart", i.e. an apartness of-I waves), is better than use of "PB".
RE: Why don't these flow rate curves count as flow-limited? - cathyf - 09-27-2021
I have a theory...
The bizarre gyrations in the inhale curve are positional. They come about when I am not wearing a cervical collar and I am NOT having crapstorms of apneas. This is my between-cluster breathing.
Here is the night before you guys convinced me to try the cervical collar:
https://www.dropbox.com/s/z27v7smqzg1dk3t/noCollar.png?dl=0
a closeup
https://www.dropbox.com/s/eqous4qcb1v0dce/noCollarClose.png?dl=0
Here's the first night with the collar:
https://www.dropbox.com/s/p7hy20iwjlq0eqt/collar.png?dl=0
Here's last night with me on vauto, without a collar:
https://www.dropbox.com/s/bc614iye6air01t/vautoNoCollar.png?dl=0
The vauto seems to help the positional apnea some, but it helps the wild gyrations on inhale a lot.
Can anyone else link this to chin tucking?
RE: Why don't these flow rate curves count as flow-limited? - Geer1 - 09-27-2021
(09-27-2021, 12:04 AM)cathyf Wrote: I'm just puzzled as to how the vauto prevents this while the autoset on EPR 3 doesn't...
I don't get how you don't see the difference in that data. Everything about that EPR = 0 data looks much worse than the other two nights, the FR curve is an absolute disaster.
The EPR = 0 data shows large amplitude exhalation flow rate and elevated respiration rate typical of this breathing issue for over 50% of the night. The EPR = 3 data shows it for only one short period. The vauto data does look noticeably better both in RR and FR, potentially due to timing controls of just being a different machines. Things as simple as different masks, clean vs dirty filters can also make a difference.
I honestly don't know exactly why the vauto does better for you but I can without a doubt 100% say your data both on autoset and vauto indicates you have restricted breathing issues and need higher levels of PS to deal with them.
RE: Why don't these flow rate curves count as flow-limited? - Geer1 - 09-27-2021
(09-27-2021, 04:14 PM)2SleepBetta Wrote: And, yes, use of either "TAA" or "DIA" (diaphragmatic intercostal asynchrony, adjectively conveying "apart", i.e. an apartness of-I waves), is better than use of "PB".
I am going to stick with calling it asynchronous breathing as we don't know what kind of asynchrony this is (if it even is asynchronous breathing like I think it is). The fast nature makes me question it would be the major muscles (diaphragm and intercostal muscles) unless one of them was twitching for some reason. This seems like more of a twitch or pulse related phenomenon.
RE: Why don't these flow rate curves count as flow-limited? - cathyf - 09-28-2021
(09-27-2021, 10:29 PM)Geer1 Wrote: I don't get how you don't see the difference in that data. Everything about that EPR = 0 data looks much worse than the other two nights, the FR curve is an absolute disaster.
This document shows just the respiration rate curve, two weeks on autoset, the previous two weeks on vauto.
https://www.dropbox.com/s/4lhoqrbwgleal5q/Comparison.pdf?dl=0
First -- it's very clear in those clusters of the recorded respiration rate jumping up to 30-40-50 that this is NOT the respiration rate. In those periods where the inhale is gyrating wildly, the exhales are still pretty regular and each exhale drops a single spike down to -50 or -60 or so and then returns immediately to oscillating around zero for a bit, and then the inhale goes up and down. It's clear that the machine is counting all of the ups and downs over the inhale as separate breaths, and goosing the recorded respiration rate, however if you simply count the number of spikes taking the exhale deep dive over time, it gives you the same 9-10-11 bpm that's the real respiration rate.
On the autoset when you see a cluster in the whole-night RR data and put up a 3/4-minute zoom, the gyrations in the inhale flow rate curve are immediately obvious. If I start at the beginning of the night and press and hold the right arrow, then I can watch the whole night of flow rate go by. It moves slowly enough that the clusters of gyrating inhales are visible as they go by, and I can pick up my finger and stop the "movie" at any time.
I can similarly take a vauto night, put it on a 3-minute zoom at the beginning of the night, push and hold the right arrow, and watch the movie go by. I'm watching the flow rate curve, and I certainly see the occasional bobbles of flattened inhales, "M" curves, depressed peaks that are characteristic of some flow limits (which the machine detects). And of course all of the distortions caused by movement. But I have run all of the "movies" of nearly 3 months of vauto flow rates, and I haven't found any case of the wild gyrations on when on vauto that I can see most nights over seven years of autoset whenever I'm not wearing a cervical collar.
When not wearing a cervical collar I get those nasty ugly clusters of obstructive events. But those are clusters -- so they are descrete time periods, and then there is the question of what goes on between the clusters. So part of the time I'm awake (yeah, that's the pathology of OSA being awakened constantly). But I think that what I am seeing is that when I'm not wearing a collar and NOT in the middle of a cluster of apnea, I'm in a cluster of this crap.
And that this doesn't happen when I'm not wearing a collar on vauto. When I sleep without a collar on vauto, I get bursts of 2-3-sometimes-4 obstructive events (as opposed to 10-20-sometimes-40-50 on autoset). But between those short clusters, while things are clearly more ragged than when I'm wearing a collar, I don't get this other gyrating inhale phenomenon at all.