What is the flow waveform "supposed" to look like

[tetragon]

Something that I've been wondering about for a bit is: what is the flow waveform supposed to look like. What got me around to asking is that archangle accused my waveform, or at least the posted snippets) of being interesting (viewtopic.php?f=1&t=71796&start=0#p661451 for the waveform, the accusation is the reply that immediately follows).

[Pugsy]

http://chestjournal.chestpubs.org/conte ... .large.jpg

Normals at above link along with some others.

[tetragon]

Thanks. I've been having a "bad search day". I keep getting everything but what I want.

[DoriC]

http://chestjournal.chestpubs.org/conte ... .large.jpg

Normals at above link along with some others.

Thanks from me too Pugsy, just what I was looking for now that I have all this fancy stuff on SH to analyze!

[Pugsy]

It might be easier if you single out a small section that you wish to understand and post it along with your questions.
Sort of like this one that I did because it got flagged as Periodic Breathing and I sent it to someone just for fun. Most of the time my PB doesn't look like real PB or CSR but this one did.

[archangle]

http://chestjournal.chestpubs.org/conte ... .large.jpg

Normals at above link along with some others.

I think the way our CPAP machines are designed, we won't see the "fuzz" on those graphs that is generated by snoring on any of our waveform data.

[rocklin]

.

http://chestjournal.chestpubs.org/conte ... .large.jpg

Normals at above link along with some others.

Thanks for the link, pugsy.

Couple of thoughts pop-up:

1. The "normal" curve is sinosodal. I wonder what the "optimal" curve looks like.

2. Who says that is what "normal" looks like? How many "normal" patients enter a sleep lab for a study? Bit of a contradiction, yes?

3. If I have a perfect curve, but dream nightly of a fiery death of myself, my wife, my children, my cat and my dog from a Extinction Level Event (ELE) will I wake up peaceful and rested?

See what I'm getting at?

.

[tetragon]

It might be easier if you single out a small section that you wish to understand and post it along with your questions.

I was mostly just wondering about what was considered normal. If you really want to see the sections whose response got me around to asking, though…

[tetragon]

2. Who says that is what "normal" looks like? How many "normal" patients enter a sleep lab for a study? Bit of a contradiction, yes?

I take it you never had a prof who gave his undergrads extra credit when they participated in research, as the subjects. Other times, researchers may visit the lecture hall of students in a related major and hand out flyer: participate in our research and you get entered into a raffle to win a gift card. Although I do admit that the "normality" of undergrads is questionable.

[Pugsy]

I was mostly just wondering about what was considered normal. If you really want to see the sections whose response got me around to asking, though…

I have some areas that look pretty much the same as yours...Some clearly marked events and some pressure pulses with nothing flagged. There was one hour or so the other morning where I had a pretty good straight red line with a lot more pressure pulses than I normally do. So I have seen in a small time frame what you have seen in a major time frame. I have no idea what the significance of these breaths or what triggers it or what the associated individual breathing graphs point to. Sorry, but I just don't have the answer to your questions about each individual breath. Where or what or when does a breath become a variation of normal or abnormal? I have no idea.

Archangle and rocklin... this graph was just shown to try to explain the little symbols that show on the ResScan report. Since ResScan is designed for medical professionals and not lay people, ResScan does not explain the symbols. It is for the tips of the breaths. If either of you have access to a better explanation of the ResScan symbols please share it. I would love to see it. I am sure it would help a lot of people.
If you want to debate the finer points of this particular graph vs who created it and their credentials vs what you see on cpap machine reports..go for it but count me out. This was simply the best graph that I could find showing the tips of the breaths which is what ResScan symbols show. I don't have the time, energy or inclination to go any deeper.

[avi123]

I could show how I checked if I have Central Apnea, by using ResScan graphs. But, it would be useless for Respironics users.

In Resmed's machines we have clear indications of snore, etc.

See here:



For wave forms we also have a clearer picture:


Checking for Cheyne Stokes or Periodic Breathing:

[archangle]

Archangle... this graph was just shown to try to explain the little symbols that show on the ResScan report.

I wasn't trying to pick a fight. The graphs you posted pretty clearly show snoring as "fuzz." This fuzz won't show up on on our graphs, so it's important to point that out to someone trying to look at data from a CPAP machine.

I think there's a deeper lesson to be learned here. A PSG inlab sleep study usually has airflow sensors right at the patient's nose. It doesn't react to mask leaks or the air going out the exhaust vent.

The CPAP machine has sensors in the machine itself. The patient is at least 6 feet of hose away. What the machine sense at the fan may be different from what happens at the patient's nose or mouth. The machine may not have as accurate a sensor, and it may not react as fast. It's a bit like listening to a conversation of someone in another room vs. someone sitting next to you.

[Pugsy]

I wasn't trying to pick a fight. The graphs you posted pretty clearly show snoring as "fuzz." This fuzz won't show up on on our graphs, so it's important to point that out to someone trying to look at data from a CPAP machine.

Yeah, I know. I wish I had graphs from our machines as examples but I looked all over the place and this one is the only one I could find with examples.

Funny thing about those snore sensors...I have finally found the explanation for some of my horrible snore clusters...not from me...My little snoring pug dog is the culprit. When he lays up by my head...I get the large snore clusters. I can't believe it took me this long to figure it out.

[archangle]

Funny thing about those snore sensors...I have finally found the explanation for some of my horrible snore clusters...not from me...My little snoring pug dog is the culprit. When he lays up by my head...I get the large snore clusters. I can't believe it took me this long to figure it out.

"Doctor, my CPAP pressure goes up every time my dog sleeps next to me. I think the machine is reacting to his snoring."

"Nurse, bring me the butterfly net."