SH chart - what is happening here?

[raisedfist]

A leak wouldn't be expected with mouth exhalation while wearing a FFM.

The FFM prevents any issues with mouth breathing for me. I think I wrote confusing before. The FFM solves all my problems. Except for the occasional sore/skin blemish. That's the only time the nasal mask comes out to play for me.

[palerider]

Thanks for posting your experiment, PR. I would be interested to see how the value of your leak compares to your MV.

Sure thing:

mouth-with-mv.png

I think it might have to do with the way it calculates negative flow, as we know, there is really no negative flow so the machine must set an arbitrary 0 line at some positive level and calculate from there taking into account mask vent rate, leaks, etc. Since inspiration must equal expiration, maybe it just sets a 0 reference at a point that will yield that result. Mine was was the same using a lowly autoset. As you said, "it's complicated".

It may be the VPAP Auto and it's 'VSync' 'automatic leak management'... I've watched on the display while the machine 'figures out' what the leak baseline is, starting out saying there's a big leak then over a few breaths, coming down to zero.

[Jay Aitchsee]

A leak wouldn't be expected with mouth exhalation while wearing a FFM.

The FFM prevents any issues with mouth breathing for me. I think I wrote confusing before. The FFM solves all my problems. Except for the occasional sore/skin blemish. That's the only time the nasal mask comes out to play for me.

Right! I think we were both a little confusing

[Jay Aitchsee]

Sure thing:

Thanks. Earlier in this thread I suggested that Leak would equal MV in a Nose In, Mouth out condition. It looks like yours are close, as were mine. Your leaks look to be about 8-9, and your MV about 10-11. Mine were similar, but my leak was higher than MV

[Spot123]

Hi, OP here. This thread has headed into a way more technical discussion than I can follow while checking in during a quick break at work.

But one thought -- any chance the original flat/bump pattern I saw was a very slow exhale through the nose? I see that the pattern is similar to some that precede a central on the more recent graph postings. The pattern I originally asked about lasted for about 40 minutes, with a pretty regular pattern too. I still haven't been able to open my mouth without blowing out my head. I've been meaning to look for more days with same pattern but haven't gotten around to it yet.

Thanks.

[Jay Aitchsee]

Hi, OP here. This thread has headed into a way more technical discussion than I can follow while checking in during a quick break at work.

But one thought -- any chance the original flat/bump pattern I saw was a very slow exhale through the nose? I see that the pattern is similar to some that precede a central on the more recent graph postings. The pattern I originally asked about lasted for about 40 minutes, with a pretty regular pattern too. I still haven't been able to open my mouth without blowing out my head. I've been meaning to look for more days with same pattern but haven't gotten around to it yet.

Thanks.

Possible, but I doubt it. Notice in the example you posted (below) there is a corresponding leak of about 10L/min, typical of a mouth exhale. Additionally, the "normal" trace posted indicates some mouth exhalation by the shape of the expiration portion, which is beginning to flatten. See viewtopic.php?f=1&t=112758&p=1085906#p1085906 for examples and viewtopic/t171982/Mystery-solved-ever-h ... l#p1255757 (below)

Also, I think to exhale that slowly through the nose would require a much longer time of exhale. Why do you resist the idea (based on this and previous posts) that you are exhaling by mouth?

mouth.jpg

Also see: viewtopic/t171982/Mystery-solved-ever-h ... l#p1255757

[jpop]

Just wanted to post a note that the Scunci thing has worked awesome for me.

Having been looking for a solution to the occasional blowouts and mouth breathing, the Scunci has worked great. Taping or a chin strap was just absolute nightmares and I would wake up a couple of times from discomfort or panic. With the Scunci I believe I have some occasional mouth breathing but just the right amount of resistance to cause me to close my mouth in a few minutes and breath through my nose. My AHIs have dropped below 1, and to date I haven't woken up midway through the evening.

So where ever the suggestion came from about the Scunci, many thanks from this well rested monkey.

[Spot123]

Why do you resist the idea (based on this and previous posts) that you are exhaling by mouth?

No particular reason, (1) except I grind my teeth so my mouth is usually clenched closed and (2) can't seem to duplicate it while I'm awake. I'm not concerned either way; the original post was in the spirit of learning and curiosity more than anything else. And when I have more time, I will read the detailed explanations more thoroughly.

Thanks.

[zonker]

Just wanted to post a note that the Scunci thing has worked awesome for me.

snoopy-dance.gif

so happy it worked for you! while i've been promoting the hell out of it, it was the gentleman who posted right before you that figured it out.

take a bow, jay!!

[Jay Aitchsee]

take a bow, jay!!

Aw shucks; thanks, Zonker

200wUFEIRIAT.gif

[Jay Aitchsee]

Why do you resist the idea (based on this and previous posts) that you are exhaling by mouth?

No particular reason, (1) except I grind my teeth so my mouth is usually clenched closed and (2) can't seem to duplicate it while I'm awake. I'm not concerned either way; the original post was in the spirit of learning and curiosity more than anything else. And when I have more time, I will read the detailed explanations more thoroughly.

Thanks.

Well, as I said above, most people can exhale easily through clenched teeth.