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Machine stops pushing air during inhalation cycle - Printable Version

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Machine stops pushing air during inhalation cycle - novatom - 01-29-2015

I'm still learning all the lingo and terms so bear with me as I try to explain this.

When I start using my CPAP for the evening, I'm quickly able to adjust/sync my breathing rate with the machine's (or the machine to mine, as it were). At the end of my exhalation cycle, the machine begins to blow air through my mask. However, I have noticed recently that it stops blowing air about 2/3 - 3/4 of the way through my inhalation cycle. In other words, as I'm inhaling, the air stops blowing before I have stopped inhaling.

Is this a function of the pressure setting? My setting is set at 6 by the sleep clinic, and in my first follow up (I've been on CPAP for approx. 4 weeks now), the doctor decided to keep my pressure at 6 for the next two months until my next follow up in March.

This is not really a big issue, it's not like it's keeping me awake (not yet), but I'm just wondering if there's a better way to ensure that the air continues to blow throughout the period that I am inhaling.

If the machine can sense my inhalation/exhalation cycles, then it should be able to sense the entire time I'm inhaling, correct?



RE: Machine stops pushing air during inhalation cycle - quiescence at last - 01-29-2015

I believe this is part of the C-Flex function to create an environment of easing pressure as you begin the exhale. It draws conclusions based on your past flow, most recent breaths, not only the current breath.

As you relax and enter sleep, all things become more steady, and the expected exhale is nearer to exactly when you do exhale. So, ease your mind, during sleep the machine will not be "taking control".

by the way - you can see those times when your inhales and exhales are erratic in the sleepyhead charts, most prevalent by wide swings in tidal volume, signaling periods of wakefulness (or in some cases potentially REM sleep).


RE: Machine stops pushing air during inhalation cycle - justMongo - 01-29-2015

I'm not really that familiar with the PR machines...
(So, take this with a grain of salt...)
My machine has a TImax setting. The Inhalation (IPAP time) is limited by TImax.
So, for me, if it were set too short, I would experience the same effect you describe.


RE: Machine stops pushing air during inhalation cycle - archangle - 01-29-2015

Novatom, we need to know what machine you have. "C-Flex" isn't enough.

Take the water tank out, turn the machine over, and look for the label on the bottom where it says something like "REF 260P." Tell us what that says. Also tell us EVERYTHING it says on the top near the display.

It probably doesn't stop completely during inhale unless it's broken, but it may reduce the pressure. Try putting your hand in the air stream coming out the vents on your mask and see if it's still blowing.

If you turn off C-flex, or change the settings, it should reduce or eliminate this effect entirely.

JustMongo, none of the ones that say "C-Flex" have a TIMax setting. That's for bilevels, which would say "BiFlex."



RE: Machine stops pushing air during inhalation cycle - novatom - 01-29-2015

My machine is a 460 PR System One REMStar 60 Series Pro with C-Flex+

It's confusing because PR has a lot of variations of this machine, but that's what it says on the bottom (I added the C-Flex+, that's what it says on the top of the machine).