Oh what a night......

[Skypilot]

The mask type is set correctly and always has been....

[JimZZZ]

Sometimes I believe that I was sleeping but was dreaming that I was awake. So, to determine whether I feel rested, I check with Sleepyhead. Frequently, I feel a lot better after I confirm my sleep quality with Sleepyhead. Speaking of head...rested/not rested status is apparently in mine.

[retired_guy]

Sometimes I believe that I was sleeping but was dreaming that I was awake. So, to determine whether I feel rested, I check with Sleepyhead. Frequently, I feel a lot better after I confirm my sleep quality with Sleepyhead. Speaking of head...rested/not rested status is apparently in mine.

Which is why I have a double down procedure to determine if I was sleeping. Sleepyhead and my cute little "fitbit" device. Actually I have a third but she has declined to stay awake at night to see if I sleep or not. So imagine my horror and frustration the other day when I left my card out of the machine and forgot to set the "fitbit" thing to "sleepy time." Just in case I didn't sleep, maybe I should go take another nap.

And Sky? Don't be a tweaker....... You're doing absolutely great!

[PaytonA]

I think that most of us are inveterate tweakers that somehow manage to restrain ourselves somewhat when it comes to CPAP.

[diamaunt]

If one is using nasal pillows but the machine thinks a Full Face Mask is being used, the machine will think the intentional leak rate is larger than it really is, and therefore the machine will think and report that the leaks are lower than they actually are.

even though the leak rates for most masks is similar, ffm or pillows or nasal,

and if you look at the charts you see differences between the same type of mask

http://z5.ifrm.com/5902/67/0/p1032022/Re..._rates.pdf

I believe the mask setting is mainly for other reasons

[vsheline]

I believe the mask setting is mainly for other reasons

Nope. That's the only reason.

[diamaunt]

I believe the mask setting is mainly for other reasons

Nope. That's the only reason.

please provide documentation of your offhand dismissal of the evidence showing most masks have similar leak rates, and yet differences in the same class of mask, which would tend to indicate that your theory doesn't hold water.

the mask type groups are more related to the dead space in each mask, which, along with the hose diameter setting allows the machine to better calculate the breathing circuit. (this has been documented).

[vsheline]

the mask type groups are more related to the dead space in each mask, which, along with the hose diameter setting allows the machine to better calculate the breathing circuit. (this has been documented).

If that is the case then I stand corrected. Thanks. Yes, it does seem possible that in some ResMed machines the mask type may influence the pressure-adjusting algorithm of APAP machines, or may influence the central-versus-obstructive apnea detection algorithm. I'll try to look into this.

But at the same time, ResMed machines which do not auto-adjust the pressure and do not distinguish between central versus obstructive apneas also need to be told the correct mask type. So I think what the mask type would be used for in those machines would be only for more accurately calculating the intentional versus unintentional Leak. But I'll try to look further into this, too. Again, thanks.

[diamaunt]

But at the same time, ResMed machines which do not auto-adjust the pressure and do not distinguish between central versus obstructive apneas also need to be told the correct mask type. So I think what the mask type would be used for in those machines would be only for more accurately calculating the intentional versus unintentional Leak. But I'll try to look further into this, too. Again, thanks.

I'd be interested in any published data you find, and/or the results of any experiments you do!

as I understand it, the machines factor in the 'dead space' in the mask to help calculate just how much pressure they need at the machine to give the set pressure in the mask, and mask geometry factors into that calculation.

the problem I have with the 'mask setting adjusts leak' is two fold,

1) PR machines have mask settings, and they report total leak not excess, so why would they care?
2) look at the pdf from resmed up in post 15, in the nasal mask column, the swift lt goes from 21@4 to 42@20cm, while the swift fx and swift II both go from 20@4 to 49@20cm, yet, they're both the same setting.

[PaytonA]

With my S8 VPAP Auto my leakage values increased when I corrected the mask setting from what the DME had set after I changed masks. My feeling is that Resmed simply wanted to simplify the setting for those who were not using Resmed masks. They may have also decided to make the vent rates more standard for each type of mask for their new masks. Just my opinion.

But at the same time, ResMed machines which do not auto-adjust the pressure and do not distinguish between central versus obstructive apneas also need to be told the correct mask type. So I think what the mask type would be used for in those machines would be only for more accurately calculating the intentional versus unintentional Leak. But I'll try to look further into this, too. Again, thanks.

I'd be interested in any published data you find, and/or the results of any experiments you do!

as I understand it, the machines factor in the 'dead space' in the mask to help calculate just how much pressure they need at the machine to give the set pressure in the mask, and mask geometry factors into that calculation.

I am not sure that I understand how mask "dead space" figures in to determining mask pressure. If you know the pressure at the blower and you know the pressure drop from the blower to the mask then you can easily calculate the mask pressure. There is no pressure drop in the "dead space".

I would be interested in the documentation on calculating the "breathing circuit". If you could point me in the correct direction, I would appreciate it.

Best Regards,

PaytonA