What exactly is a "flow limitation" ?

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zonker
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Re: What exactly is a "flow limitation" ?

Post by zonker » Mon Dec 27, 2021 4:44 pm

rick blaine wrote:
Mon Dec 27, 2021 4:35 pm
If I may take up a little of your time ...
very well put. and it's a fine example of just why i've given up trying to suggest to people that they keep to one topic thread. if *I* were one of the forum members that was busily giving out advice left and right, then i'd probably push harder. but i'm just another user, trying to get through it all. besides, i've decided i've better things to do.

to paraphrase an old saying, life is too short to dance with ugly partners.
people say i'm self absorbed.
but that's enough about them.
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Re: What exactly is a "flow limitation" ?

Post by dataq1 » Mon Dec 27, 2021 5:51 pm

rick blaine wrote:
Mon Dec 27, 2021 4:35 pm
If I may take up a little of your time…
What did that post have to do with the OP’s question?

If you need to expound on staying on topic, start a new thread to discuss that, instead of persisting in hijacking.
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Re: What exactly is a "flow limitation" ?

Post by lars_the_bear » Tue Dec 28, 2021 4:22 am

rick blaine wrote:
Mon Dec 27, 2021 4:35 pm
If I may take up a little of your time ...
My goodness. I don't think I've seen my failings so comprehensively and studiously documented since my first wife divorced me. You only omitted to point out that I repeatedly leave the toilet seat up.

I have to say that I'm baffled. What started out as something that seemed to me to be a perfectly reasonable question about how CPAP machines work, has actually turned into a dissertation-length exposition of my inadequacies.

Maybe nobody can answer my question. Maybe it has been answered somewhere else. But to take over the thread with a long essay on how I should not even have asked it? Honestly, you guys. You blow my mind, really you do.

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Re: What exactly is a "flow limitation" ?

Post by MMcG » Tue Dec 28, 2021 4:49 am

lars_the_bear wrote:
Tue Dec 28, 2021 4:22 am
rick blaine wrote:
Mon Dec 27, 2021 4:35 pm
If I may take up a little of your time ...
My goodness. I don't think I've seen my failings so comprehensively and studiously documented since my first wife divorced me. You only omitted to point out that I repeatedly leave the toilet seat up.

I have to say that I'm baffled. What started out as something that seemed to me to be a perfectly reasonable question about how CPAP machines work, has actually turned into a dissertation-length exposition of my inadequacies.

Maybe nobody can answer my question. Maybe it has been answered somewhere else. But to take over the thread with a long essay on how I should not even have asked it? Honestly, you guys. You blow my mind, really you do.

BW, Lars.
I think that you have to realise that most people on this forum are sleep deprived to some extent. They wouldn't be here otherwise. That makes us all a bit grumpy to put it mildly!

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Re: What exactly is a "flow limitation" ?

Post by lars_the_bear » Tue Dec 28, 2021 5:48 am

MMcG wrote:
Tue Dec 28, 2021 4:49 am
I think that you have to realise that most people on this forum are sleep deprived to some extent. They wouldn't be here otherwise. That makes us all a bit grumpy to put it mildly!
Fair enough; and I'm probably not at my best at present, either.

But still... I have other questions, and I now have absolutely no clue how, where, or even whether to ask them.

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Re: What exactly is a "flow limitation" ?

Post by Pugsy » Tue Dec 28, 2021 6:45 am

OMG I get sick with some sort of nasty stomach bug and can't be here for a day and all hell breaks loose.

All this crap could be prevented if people, new to the forum, would just take the time to read a sticky very prominent on the top of the announcements section called "NEWBIES PLEASE READ BEFORE POSTING"... https://www.cpaptalk.com/viewtopic.php? ... 4#p1260774
and note what I have highlighted in red to get people's attention since apparently no one seems to want to take the time and read what I bothered to compose to help newbies get the best help here.
Start your own thread about your own specific issues/questions or problems...don't piggy back it onto someones else's thread because it gets confusing when we start offering different ideas to different people in the same thread.
Even if you just have a lot of different questions specific to you and there will probably be many of them...keep all your various question in one thread for a while. Don't make a new thread/topic with each new question. It helps us help you better if all your jumble of questions is in one thread. Even if the questions are widely varied in topic.
The whole idea is to keep as much as possible in one thread so that we don't have to go back and read half a dozen threads you started to see what might have already been said. We often don't have the time to do that...anything that you can do to save us time will mean we can help you better and faster.
I realize that the way we do things here, or prefer to do things here, goes against what a lot of other forums do...hey guess what...we aren't other forums and we tend to know what works best for our own rather unique situations here. It's been this way for ages...I posted the "NEWBIES PLEASE READ" thread back in 2018 when I got the powers to make stickies and it was preferred that people stick to one thread long before I posted that sticky. It's been that preference since I became a member here in 2009 and probably before then.

Is it a hard fast rule??? Well no, it isn't but it would sure help us help people better and faster and more completely if people would try to stick to it. My own personal opinion on it...if so and so wants help here and people sure expect to get the best help here and they want it really fast it seems sometimes, they should adapt to the general forum preferred way of doing things but if they don't want to do that..so be it.... but they risk having their posts ignored by forum members who simply don't like a gazillion threads from someone who hasn't even bothered to read the "NEWBIES PLEASE READ BEFORE POSTING" thread. If I have time or happen to remember past history details I just answer the person as best I can...if I don't then I just don't reply. Simple as that.

Now sometimes I do try to explain to people that it would be best if they consolidated all their random thoughts or questions into one thread. I did that the other day and got accused of YELLING at someone when that was the farthest thing from my mind. I wasn't ugly or accusatory or anything like that. I simply explained why we (as the forum in general) preferred to do things here and I essentially was told that I was wrong. Hmmmmm....now that will provoke me into YELLING for sure and there's a good chance my potty mouth will surface. :lol: For sure guarantees that person a place on my Foe list so I will simply ignore that person. I figure if they don't want my help...I won't offer it and won't waste my time reading whatever they post.

Finally if someone wants to persist in creating a gazillion new threads about something they should at least have the courtesy to include links to past history they have already generated. So that people can go back and easily read past discussions. Does anyone ever do that...hell no...they just expect us to remember anything and everything about them and still expect priority one help.

They don't want to do what is needed to obtain the best help here...pisses me off for sure...and then when we suggest that people do what we know means getting the best help....we get yelled at or bitched at or told that other forums don't do it that way. What PR said about "posting random thoughts" here....I actually thought many times but just never said it.

Because I actually covered that point in the NEWBIES PLEASE READ BEFORE POSTING thread....that not many seem to bother to read.

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Re: What exactly is a "flow limitation" ?

Post by lars_the_bear » Tue Dec 28, 2021 7:40 am

@pugsy:

I suppose the confusion I have is where you (or somebody) says:

"Even if you just have a lot of different questions specific to you..." (my emphasis)

The question I raised in this thread does not seem to me to be specific to me. It's a general question about how CPAP machines work. At no point did I mention me, my problems, my treatment, or even my particular machine. I really don't see what purpose is served by asking that question in a thread that really is about me, and is full of OSCAR graphs and what-not.

If people who use this forum really do prefer a "one-thread-per-person" mode of interaction, with many topics that are only tangentially related all stuffed into one thread, then of course I will try to follow that. I confess that it seems very odd to me, however.

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Re: What exactly is a "flow limitation" ?

Post by dataq1 » Tue Dec 28, 2021 7:45 am

Back on topic:
Amsleepnbetta posted this in a different thread, but since it is so closely addresses the Original post here it is worthy to repeat it here:

Amsleepnbetter said:
First, before adding comments to pugsy and others' good comments in lars-the-bear thread, the following note is in passing and not intended to dismiss the NIH research dataq1 linked to there. It was sponsored by Respironics, done with Respironics devices and completed in or before 2012. Two of the researchers had done work partly funded by grants from Resmed and from Respironics. As dataq1 mentioned, flow limitation was not its focus and apnea were. Resmed APAP device performance is reportedly quite different and likely has changed in the interim (Resmed has connections to related patent applications dated in 2011 and 2018).

In fewer words than below, I summarize here my understanding of "flow limit" in claiming that a Resmed "FL" flag and the separate significations of "flow limitation" are two different but related things that are commonly confused. A FL is a Resmed symbol for a mix of real and potential airflow reducing and breathing effort related components. In general and in human breathing (i.e., in human ventilation) a flow limiter is a condition or device that causes a reduction in (air) flow and flow limitation is the effect of that flow limiter.

I've done a lot of work, some illustrated (now here below), analyzing raw Resmed flow rate and FL data in trying to understand only the Resmed "FL" informational flag. The FL is about flow (ventilation) reduction, detection of imminent threats of it and the level of breathing effort (work of breathing). Again, the more limited ordinary meaning of "flow limitation" of any flowing matter or substance is that a flow of that same matter is, was, or will be reduced from one rate to a lower rate for some period of time.

The four elements underlying a FL can be detection of airflow volume or flow rate reduction, detection of deformed chair- or M-tipped, flattened or other irregular inspiratory wave tips, detection of a flattened inspiratory wave and detection of one or the other or both of two breath timing matters. The interactive timing factors are respiratory rate (breaths per minute) and the ratio of inspiratory time to total breath time (the physical work time of a breath, the "duty cycle"). The exact relationships among and relative impacts of the four broad flow factors are patented secrets.

Among other things, analysis of raw Resmed flow rate data leaves me with an impression that detection of a wave shape irregularity mostly alerts the machine to be ready to raise pressure if a series of it develops or grows. However, as others can check their flow rate, I frequently see 4-second severity of 0.01 to .02 FL begin in the expiratory part of the breath cycle for one M-tip wave or of one sigh wave that has appeared amid very normal waves. How much shape alone may contribute to FL intensity and duration is unknown to me. I suspect ventilation drop and breathing work are main components of FL.

As I understand them the FLs addresses the two most important sleep ventilation and sleep soundness factors, tidal volume reductions and the work of breathing, while mere "flow limitation" signifies only one ventilation factor, tidal volume reductions. If excessive breathing effort is required to maintain adequate tidal volume (ventilation) then sleep becomes fragmented and it seems likely there would be additional detrimental health effects. We must get the ventilation we need (tidal volume, TV) without stressful effort to have restful sleep.

One of the lingering questions about FL in my mind is what determines a drop in a FL to or toward severity zero. How do favorable ventilation, duty cycle or shape changes from less desirable levels get reflected in FL? Work in dataq1's thread (below) touch on that in showing FL varying with TV drops.

Links to two research papers about breathing, one for human and one for equine breathing, follow. The equine account is very similar and simpler to read before tackling the more detailed human account. Both papers explain the many parallel factors in breathing airflow limitation. Both, among much else, emphasize the flow limitation effect of chin and muzzle tucking. The equine account describes the benefits of devices placed to open nasal breathing (valve?) passages. Don't some people use such external nasal devices?

Links:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3770742/
https://www.ivis.org/library/equine-res ... ory-system


The entirety of the thread can be found at: https://www.cpaptalk.com/viewtopic/t183 ... l?start=30
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Re: What exactly is a "flow limitation" ?

Post by dataq1 » Tue Dec 28, 2021 8:15 am

Pugsy wrote:
Tue Dec 28, 2021 6:45 am
All this crap could be prevented if people, new to the forum, would just take the time to read a sticky very prominent on the top of the announcements section called "NEWBIES PLEASE READ BEFORE POSTING".
Respectully, Maybe, just maybe, posters as myself, view seeking technical information as different than seeking advice on their individual therapy.

Certainly It creates unnecessary confusion if a newbie were to post 'what do I do with my therapy because of what happened on Sunday night' and then create a new thread "what do I do with my therapy because of what happened on Monday night", etc.

That situation is significantly different than asking for the community's collective knowledge about 'the pros and cons of a certain humidifer, versus the definition of an H event flag. Perhaps only in my mind, but those two questions deserve two different threads.

I am reluctant to say this out load, but "all this crap" was triggered by Palerider's personal attack. Had he, in assuming your place as moderator, been a bit more polite not reverted to personal attack, instigating this hijack, "all this crap could have been prevented".

YMMV
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Re: What exactly is a "flow limitation" ?

Post by Pugsy » Tue Dec 28, 2021 8:18 am

lars_the_bear wrote:
Tue Dec 28, 2021 7:40 am
I suppose the confusion I have is where you (or somebody) says:

"Even if you just have a lot of different questions specific to you..." (my emphasis)

The question I raised in this thread does not seem to me to be specific to me. It's a general question about how CPAP machines work. At no point did I mention me, my problems, my treatment, or even my particular machine. I really don't see what purpose is served by asking that question in a thread that really is about me, and is full of OSCAR graphs and what-not.

If people who use this forum really do prefer a "one-thread-per-person" mode of interaction, with many topics that are only tangentially related all stuffed into one thread, then of course I will try to follow that. I confess that it seems very odd to me, however.
Well.....number one flow limitations has over 7 K hits just from the forum search.
https://www.cpaptalk.com/search.php?key ... imitations
Now granted the forum search feature sucks most of the time but "flow limitations" have been discussed ad nauseam here but no one will take the time to maybe just do some reading here.
An idea pops into their head and they ask a question without bothering to do any research...and your question came on the heels of in another thread where you posted your 2 different flow limitation graphs...what did you think we were going to think???
We are supposed to read your mind???

No where have I ever said that it is "one person one thread" forever forum....use some common sense folks.

We usually are pretty forgiving and will give newbies 2 or 3 new random different topics before someone gets annoyed enough to ask them to please keep random thoughts/questions to one thread for now. We don't know when a newbie first posts here if they are just passing through or will plan on staying for a while.

To ALL:
Folks...this is for everyone who is new and want to argue this way of doing things....it's not a hard fast rule...the only hard fast rule here is that there are no hard fast rules.
You are free to post as many different threads or topics as you wish....BUT bear in mind that if you annoy the very people you are relying on for information you may not like the results or lack of results you may get or not get.

Veteran forum members have the same rights as everyone else and sometimes when they get annoyed enough it shows...it's just the way it is. You get to voice your opinion and we get to voice ours.

The very reason we request consolidation of your new thoughts or questions is OUR EFFORT to best help you and as QUICKLY as possible. We know what works best for US TO HELP YOU. It is the way we can BEST help you...it is something WE NEED and expect but if you don't want to do that...that's okay too BUT just bear in mind that it does compromise our ability to help and to be honest it compromises our DESIRE to help...especially when people want to argue the point.

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Re: What exactly is a "flow limitation" ?

Post by MMcG » Tue Dec 28, 2021 8:31 am

lars_the_bear wrote:
Tue Dec 28, 2021 5:48 am
MMcG wrote:
Tue Dec 28, 2021 4:49 am
I think that you have to realise that most people on this forum are sleep deprived to some extent. They wouldn't be here otherwise. That makes us all a bit grumpy to put it mildly!
Fair enough; and I'm probably not at my best at present, either.

But still... I have other questions, and I now have absolutely no clue how, where, or even whether to ask them.

BW, Lars.
There's always the private message option. I found most people here to be very helpful and got some very good feedback privately too.

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Re: What exactly is a "flow limitation" ?

Post by dataq1 » Tue Dec 28, 2021 8:34 am

Pugsy wrote:
Tue Dec 28, 2021 8:18 am
Well.....number one flow limitations has over 7 K hits just from the forum search.
Seriously, if that is the number 1 defense of Palerider's complaint,
then the appropriate response to the Original Question should have been:

"This question has been asked and answered 7K times, do your own research before creating a new thread ( don't bother us ) "


Can we get back to the topic ????
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Re: What exactly is a "flow limitation" ?

Post by lars_the_bear » Tue Dec 28, 2021 8:39 am

OK. It seems that this is a good place to get help, if you're willing to subject yourself to rudeness, arrogance, and a disdainful disregard for any criticism, however instructive it is intended to be.

Thanks to all who have helped, but this isn't for me.

Lars out.
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Re: What exactly is a "flow limitation" ?

Post by Pugsy » Tue Dec 28, 2021 8:51 am

dataq1 wrote:
Tue Dec 28, 2021 8:15 am
I am reluctant to say this out load, but "all this crap" was triggered by Palerider's personal attack. Had he, in assuming your place as moderator, been a bit more polite not reverted to personal attack, instigating this hijack, "all this crap could have been prevented".
And I disagree....we have had this same sort of "discussion" so many times that I have lost count and PR wasn't even involved.
Just the other day I had it happen to me and I wasn't rude or blunt or sarcastic and in fact I was trying to ward off direct "attacks" that I knew were on the horizon.

Some members are rather blunt and use 2 X 4's when delivering messages. Short and sweet and very blunt but that doesn't mean it's not the truth.

PR is blunt and often uses a 2 X 4 but he isn't the only one here that does that...and there's no rule against being blunt and direct with one's comments. Remember there are really no hard fast rules here unless they violate the terms of agreement well all agreed to when we became member of the forum here (that no one ever bothers to read I am sure).
dataq1 wrote:
Tue Dec 28, 2021 8:15 am
espectully, Maybe, just maybe, posters as myself, view seeking technical information as different than seeking advice on their individual therapy.

Certainly It creates unnecessary confusion if a newbie were to post 'what do I do with my therapy because of what happened on Sunday night' and then create a new thread "what do I do with my therapy because of what happened on Monday night", etc.

That situation is significantly different than asking for the community's collective knowledge about 'the pros and cons of a certain humidifer, versus the definition of an H event flag. Perhaps only in my mind, but those two questions deserve two different threads.
You are certainly free to differ in your opinion as to what deserves two different threads and you are certainly free to differ with how you think this forum should do things.
I just love it when newbies come here and tell us that the way we have been doing things here for years is the wrong way.

We do the best we can given what we are given and I respectfully disagree with pretty much all you said.
Are there exceptions to the rule??? Of course there are but again "use some common sense folks".
The cold fact of life is if someone posts repeatedly to new threads and it comes to the point that someone mentions that it would be best if someone would keep to one thread....it has annoyed some forum members and maybe...just maybe it would be best to heed that advice.
Now what happens when a person doesn't heed that advice....not much except fighting about it derails a thread like this one here...no one gets banned...no one gets posting privileges restricted...nothing much happens except that a veteran forum member will likely just ignore that person and that person might miss out on some real help down the road.

Those forum members who often use 2 X 4s....actually have a wealth of knowledge to share but they simply don't have much patience for people that annoy them. It is the way they are and there's no rule against being short on patience here either. I used to cringe a bit when I saw someone's 2 X 4 come out but after essentially getting the same sort of response when I say the same thing but much softer and more politically correct...I have decided that I don't care any more.
If it doesn't violate the terms of agreement...I won't do or say anything.
No personal attacks or name calling or something similar was ever said by PR in this thread. He voiced a thought that went through his head that went through mine before he ever said what he said. He didn't call anyone some rude name or attack someone's IQ or anything like that.

Me....my patience grows shorter every day it seems like.

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Re: What exactly is a "flow limitation" ?

Post by Pugsy » Tue Dec 28, 2021 8:54 am

dataq1 wrote:
Tue Dec 28, 2021 8:34 am
Pugsy wrote:
Tue Dec 28, 2021 8:18 am
Well.....number one flow limitations has over 7 K hits just from the forum search.
Seriously, if that is the number 1 defense of Palerider's complaint,
then the appropriate response to the Original Question should have been:

"This question has been asked and answered 7K times, do your own research before creating a new thread ( don't bother us ) "


Can we get back to the topic ????

Come on now...we both know I never said that someone needs to do their own research.

Too late on getting back on topic...
all this shit slinging "discussion" has run off another new member because they don't like the atmosphere here.

I knew I should have locked this thread this morning when I first saw it.
I should have seen in my crystal ball where this was leading...another major derailment of a thread.

So....I guess I will lock it now.

Have a nice day.

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