Mask vent rate?

[djtowle]

Hello, can someone help me with the ‘official’ term for the rate that a mask vents air to prevent CO2 buildup. And where can I find this info? I am specifically interested in the f&p eson, Phillips Amara and Mirage Activa. But would also like to find this specification for other masks.

Tia

[Goofproof]

It is listed in the flyer on every mask, the vent rate is also different for every pressure used, and on auto varies with every pressure change. Jim

The vent rate , means the amount of air vented by the mask NOT counting other leaks, it's measured in LPM! Different machines do the math differently in figuring the number. Some add the mask leak and other leaks as total leaks (Resmed).

[grayghost4]

page 5 and 6 will give you the tecnical specks .... most manuals have it.

https://www.google.com/url?sa=t&rct=j&q ... dZgDjm75a0

[Wulfman...]

Hello, can someone help me with the ‘official’ term for the rate that a mask vents air to prevent CO2 buildup. And where can I find this info? I am specifically interested in the f&p eson, Phillips Amara and Mirage Activa. But would also like to find this specification for other masks.

Tia

For all intents and purposes it's called the "Vent Flow Rate" or "Pressure Flow Curve".

https://resources.fphcare.com/resources ... 8434-e.pdf

https://www.directhomemedical.com/masks ... ctions.pdf

https://www.resmed.com/us/dam/documents ... er_eng.pdf

https://www.directhomemedical.com/masks ... -guide.pdf


Den

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[djtowle]

Thank you for the quick responses. Found my ESon booklet. Thanks for link to Amara manual I couldn't find that one here.

So next question. How do I find actual rates verses the theoretical rates in the documentation. Is the 'Leak/leak rate' in myAir and Sleepyhead the total leak plus the exhaust vent? or is this software doing some additional math to calculate a value. In other words does 'leak rate' just show how much air the machine is pumping through the pipe when I am not inhaling?

And next: My Eson mask chart shows a exhaust flow of about 30 L/Min at pressure 10.

My Air shows a leak rate of about 7-8 Pressure not available

Sleephead for the same night is show a leak rate of about 8.4 at pressure 10. Pretty close alignment with the limited info in MyAir.

So if the chart says 30 and I am seeing less then 10...?

And thank you for the additional links this is very helpful!

[Pugsy]

ResMed machines report excess leak only....the leak above the expected vent rate.
ResMed machines subtract the estimated vent rate prior to ever reporting any leak.
If you see 10 L/min shown...that's AFTER the vent rate has been removed from the calculations...excess leak only.
There is no way to know exactly what number ResMed uses to subtract as the vent rate so that it ends up reporting only excess leaks.

ResMed is the only brand machine that reports only excess leak....all other brands report total leak.

So if you use a ResMed machine studying the vent rates for each mask won't tell you much.

[djtowle]

So the machine is recording to the SD card only the excess leak? interesting. I wonder what value it is using for subtraction. Weird.

[Wulfman...]

So the machine is recording to the SD card only the excess leak? interesting. I wonder what value it is using for subtraction. Weird.

You haven't stated which machine you're using or the pressure(s). "MyAir" is specific to ResMed machines.
But, it depends on the machine, and becomes more complex depending on the pressure......if it's fixed or variable.


Den

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[palerider]

So the machine is recording to the SD card only the excess leak? interesting. I wonder what value it is using for subtraction. Weird.

It's not too difficult to calculate the base leak rate, when you've got access to the high rate flow and pressure data inside the machine.

On my S9 Vpap Auto, it shows leak in real time on the display... and I've watched it zero in after a few breaths... first it's showing big leaks when I inhale, and then as it figures out what's going on, it settles down to 0.

Most masks have intended vent rates that are pretty similar... somewhere around 20lpm @ 4cmh2o up to something around 50lpm @ 20cmh2o...