What Does the Mask Type Setting on CPAP Machines Do?

Wife and I both have S10 Autoset machines. And we are both using n30i nasal masks. I was going through the clinical menus yesterday and my machine was set for pillows and her machine was set for mask. I changed them both to nasal mask or whatever it said. So what changes does the machine make with the mask type settings?

RobertS975 wrote: ↑

Tue Nov 26, 2019 8:00 am

Wife and I both have S10 Autoset machines. And we are both using n30i nasal masks. I was going through the clinical menus yesterday and my machine was set for pillows and her machine was set for mask. I changed them both to nasal mask or whatever it said. So what changes does the machine make with the mask type settings?

Depending on who you ask, it may have something to do with leaks calculations (with older generation machines this was definitely true) but it does have an effect on the precise pressure adjustments the machine performs to compensate for the differing resistance to air flow that different masks present.

ResMed never really tells us exactly what the mask setting does.
When I first started therapy the old manuals said it had to do with the vent rate that was subtracted prior to the leak reporting since ResMed machines report only excess leak.
Now there is no mention as to that function. My own personal experiments using the various mask settings didn't show any difference in leak numbers.

More likely it has to do with the inherent resistance in the masks which affects how the machine goes about determining pressure delivered in some fashion. Again...they don't ever really explain it...they just say do it and don't say why.

It might still affect the leak numbers as well but I couldn't see it with my experiments. I don't think it is as critical of an issue in most cases as it is made out to be. I used a nasal pillow setting for over a week with my Respironics full face mask experiment before I remembered to change it...and there was absolutely no change in anything that I could see or feel.

Full face masks of yore (long ago) probably had a lot more resistance in them but as the years have gone by masks and silicone have changed a lot. Maybe 10 or 15 or 20 years ago it was more important both from a resistance standpoint and a venting standpoint to have a selection. I dunno.

If you can find specific documentation as to "why" it is important to have the right mask selected....please share it.
Nothing I ever found actually explained the why behind it.

According to the N30i manual, you should be setting the Mask to Pillows.

N30i Manual wrote:Technical specifications
Mask setting options
For AirSense, AirCurve or S9: Select ‘Pillows'.

I haven't seen any ResMed documentation on the exact reason, and I *think* it's role mights multi-faceted.

I tend to lean towards leak and pressure calculation. With modern day ResMed masks, the mask type setting is not set to the actual mask type. For example, with the N20 the user guide says to set the mask setting to Nasal Pillow. Looking at the published venting pressure flow curve the N20 is the same as the ResMed pillows.

Any idea what I should be setting for Hybrid mask like the Amara View?

fljoemon wrote: ↑

Tue Nov 26, 2019 6:23 pm

Any idea what I should be setting for Hybrid mask like the Amara View?

For a ResMed machine all the hybrid types are considered full face masks.