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A Micro Leak Issue
#1
A Micro Leak Issue
So I have this disturbing thing going on with a micro leak that I have been trying to figure out. When I inhale quickly everything is fine right until I end the inhale, then I get this little pfft of a leak, then all is good again. I can hear and feel the pfft. Yes this has to do with leaks and pressure.

To figure this out I had to take kind of a stop motion look at what the system is doing.

1. When I start to inhale the mask actually sees a pressure drop because I am pulling air out of the mask
2. The CPAP detects the drop in pressure and starts ramping up flow to replace the air I removed from the mask and get the pressure back to the level it wants.
3. The faster my inhale, the faster the CPAP ramps up.
4. Things may happen fast, but nothing happens in zero time
5. At the end of my inhale, I have stopped pulling air out of the mask and the pressure is going up, and it could be going up pretty fast
6. The CPAP finally detects that the pressure is up and ramps down the blower

I have stopped inhaling, the blower is still going full blast trying to catch up, my face moves as I stat to exhale, the pressure goes up even more with my starting to exhale and pfft the micro leak happens until the blower drops enough to bring the pressure back to normal.

So what creates the pressure in the CPAP system? Pressure increases when air flows into the mask faster than it can flow out of the mask.
Air flows out through the vent, leaks, and on your inhale
Air flows into the mask from the hose/blower and your exhale

The leak can start from an increase in pressure caused by the CPAP trying to increase the therapy pressure, or at the end of your inhale.
The leak can also start from your face moving enough to disturb the seal between your face and the mask.

Once started the leak stops if what started it has stopped and if the pressure/flow rate is low enough to re-seal the mask.

As you can tell, I think too much, but these little pfft's were really bothering me.
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#2
RE: Post: #1 | [split] A Micro Leak Issue
(03-29-2016, 11:40 AM)PoolQ Wrote: So I have this disturbing thing going on with a micro leak that I have been trying to figure out. When I inhale quickly everything is fine right until I end the inhale, then I get this little pfft of a leak, then all is good again. I can hear and feel the pfft. Yes this has to do with leaks and pressure.

To figure this out I had to take kind of a stop motion look at what the system is doing.

1. When I start to inhale the mask actually sees a pressure drop because I am pulling air out of the mask
2. The CPAP detects the drop in pressure and starts ramping up flow to replace the air I removed from the mask and get the pressure back to the level it wants.
3. The faster my inhale, the faster the CPAP ramps up.
4. Things may happen fast, but nothing happens in zero time
5. At the end of my inhale, I have stopped pulling air out of the mask and the pressure is going up, and it could be going up pretty fast
6. The CPAP finally detects that the pressure is up and ramps down the blower

I have stopped inhaling, the blower is still going full blast trying to catch up, my face moves as I stat to exhale, the pressure goes up even more with my starting to exhale and pfft the micro leak happens until the blower drops enough to bring the pressure back to normal.

So what creates the pressure in the CPAP system? Pressure increases when air flows into the mask faster than it can flow out of the mask.
Air flows out through the vent, leaks, and on your inhale
Air flows into the mask from the hose/blower and your exhale

The leak can start from an increase in pressure caused by the CPAP trying to increase the therapy pressure, or at the end of your inhale.
The leak can also start from your face moving enough to disturb the seal between your face and the mask.

Once started the leak stops if what started it has stopped and if the pressure/flow rate is low enough to re-seal the mask.

As you can tell, I think too much, but these little pfft's were really bothering me.


This is interesting to me because during my sleep study titration test I noticed at one point in time the tech had changed something and I felt like the machine was reacting slowly to (lagging) my breathing - sort of what you are describing, I would start to inhale and there would be a moment of "vacuum" and the suddenly the machine would increase the pressure and I could breath in.

Then I would start to exhale and there would be a huge build up of pressure as I tried to exhale and then suddenly the pressure would go away and I could exhale.

The delay seemed to be around 1/2 second to 1 second - enough so that it was "interesting" to play with. I found that if I exhaled quickly, I could cause a leak, if I exhaled more slowly it would not leak.

After a little while of laying there playing with it instead of sleeping like I was supposed to do, the tech changed the settings and suddenly the machine was much more in sync with my breathing - I am pretty sure it was during the BiPAP portion of my titration. But, I am certain settings were changed by the tech and not just me getting used to it.
I am not a Medical professional and I don't play one on the internet.
Started CPAP Therapy April 5, 2016
I'd Rather Be Sleeping
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#3
RE: [split] A Micro Leak Issue
In both cases: Is exhalation relief turned ON or OFF?

If EPR turned on on Resmed machines, the blower behavior is subtly different than it is when EPR is turned off. Likewise on PR machines, the blower behavior is subtly different when Flex is turned on vs. when Flex is turned off.

Questions about SleepyHead?  
See my Guide to SleepyHead
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#4
RE: [split] A Micro Leak Issue
(03-29-2016, 03:44 PM)robysue Wrote: In both cases: Is exhalation relief turned ON or OFF?

If EPR turned on on Resmed machines, the blower behavior is subtly different than it is when EPR is turned off. Likewise on PR machines, the blower behavior is subtly different when Flex is turned on vs. when Flex is turned off.

his about info says he's using some type of aircurve, pressure info (5.8, 15, PS4.4) suggests a vauto, which means that easybreath is turned on and controls the ramping of pressure from current epap up through the 4.4 ps.

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#5
RE: [split] A Micro Leak Issue
EPR is only available when my machine is in CPAP mode, I don't use that
Easy-Breathe is only available in S mode, I don't use that

If you ask the machine to change pressure in either direction too quickly it simply cannot respond fast enough and you can cause a pressure spike just like FrankNichols is talking about. The motor in the blower has mass and once it gets moving at a speed and then request to change that speed quickly it will experience a lag
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#6
RE: [split] A Micro Leak Issue
Remzzzs take care of 'micro leaks' for me, among other things. With my Simplus sans Remzzzs, I get pinhole size leaks that go into my eye. They're expensive ($25/month) but worth it.
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#7
RE: [split] A Micro Leak Issue
(03-29-2016, 06:49 PM)PoolQ Wrote: EPR is only available when my machine is in CPAP mode, I don't use that
Easy-Breathe is only available in S mode, I don't use that

If you ask the machine to change pressure in either direction too quickly it simply cannot respond fast enough and you can cause a pressure spike just like FrankNichols is talking about. The motor in the blower has mass and once it gets moving at a speed and then request to change that speed quickly it will experience a lag

Easybreathe is always enabled in vauto mode. It is not selectable but it is in use.

Yes I can make my VPAP auto do that too by taking a deep rapid breath and shutting it off quickly. It is called fluid hammer. That is not the way that you breathe when you are asleep. The solution is: Quit doing that. When you are trying to fall asleep, try to breathe the way that you do when asleep.

If you insist on not changing your waiting to fall asleep breathing habits you might try increasing the "cycle" sensitivity.

Best Regards,

PaytonA

Admin Note:
PaytonA passed away in September 2017
Click HERE to read his Memorial Thread

~ Rest in Peace ~
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#8
RE: [split] A Micro Leak Issue
Yep water hammer and for some reason I do it when I first lay down and have to remind myself to stop

No idea about easy-breathe, I was just quoting the manual "The comfort feature Easy-Breathe is available in S mode on the AirCurve 10 VAuto and
AirCurve 10 S device." bottom of page 8 AirCurve 10 VAuto +S +ST clinician manual
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#9
RE: [split] A Micro Leak Issue
(03-31-2016, 10:42 AM)PoolQ Wrote: Yep water hammer and for some reason I do it when I first lay down and have to remind myself to stop

No idea about easy-breathe, I was just quoting the manual "The comfort feature Easy-Breathe is available in S mode on the AirCurve 10 VAuto and
AirCurve 10 S device." bottom of page 8 AirCurve 10 VAuto +S +ST clinician manual

That means that it is available to use if you want or not in S mode. In auto mode, you are using easy breathe period, no option.

Best Regards,

PaytonA

Admin Note:
PaytonA passed away in September 2017
Click HERE to read his Memorial Thread

~ Rest in Peace ~
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#10
RE: [split] A Micro Leak Issue
OOOoops!!!

Admin Note:
PaytonA passed away in September 2017
Click HERE to read his Memorial Thread

~ Rest in Peace ~
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