Dreamwear FFM us

[RichieC]

Last night I managed to get in my first full night sleep with the dreamwear full face mask (with a little help from melatonin). But I noticed when I lay on my side I lose air pressure by cutting off the air supply. I really like how comfortable this mask is especially with the air hose on top of my head, any advice on how I can make this work? Thank you.

[ChicagoGranny]

But I noticed when I lay on my side I lose air pressure by cutting off the air supply.

How do you know air pressure is being lost?

The mask was designed and tested so that when one side is completely blocked there is enough air pressure to the mask from the other side to maintain the set pressure.

[ragtopcircus]

What do you have “mask type” set to?

[Pugsy]

edited to remove distraction since it wasn't helpful

[ragtopcircus]

What do you have “mask type” set to?

Respironics machines (which the OP has in the profile) don't have mask type choices like ResMed machines do.
Respironics machines use a Resistance setting which people often confuse with mask type choice but its not the same thing.

They serve a similar purpose, and it is indeed called “Mask Type” in the Dreamstation menus. It’s under “Comfort”. The choices will be X0 to X5.

[Pugsy]

edited to remove distraction since it wasn't helpful

[ragtopcircus]

What do you have “mask type” set to?

Respironics machines (which the OP has in the profile) don't have mask type choices like ResMed machines do.
Respironics machines use a Resistance setting which people often confuse with mask type choice but its not the same thing.

They serve a similar purpose, and it is indeed called “Mask Type” in the Dreamstation menus. The choices will be X0 to X5.

I am going to politely disagree with your thoughts on this issue and leave it at that.
I have lots of experience with Respironics machines (I still own one) and Resistance control and with ResMed machines and mask type choices...and I just don't agree with you.
Have a nice day.

I still have one too, and experience with designing embedded control products. Also, the effect you experience will be proportional to your maximum flow rate. You may well experience less effect than someone else.

No disrespect intended to you or your many great contributions here, but Resmed and Respironics are equally affected by basic physics.

[ragtopcircus]

It is a series circuit, and the pressure sensor is at the source instead of the load. The machine cannot accurately determine the pressure at the load if it t does not know the impedance of every element between the source (fan) and load (the patient).

[ragtopcircus]

For example:
If I use a large size F20 (lots of frontal area) on X0, it sucks in forcefully toward my face when I inhale and pushes out when I exhale. It feels a little like breathing through a straw. On a big “catchup” breath, I’ll sometimes pop the anti-asphyxiation valves. The mask itself has little restriction, but there is some in the elbow.

On X1, all is well. The mask pumping is reduced, and I don’t pop the valves.

Ok, now add a Z1 HME between the hose and mask (can’t use the humidifier during a power outage). Now the mask pumping and valve popping is back. X2 is a little better, but bump it up to X3 and all is well again.

What happens on X5? Whoosh!!! The machine is overcompensating, because it is overestimating the effect of mask resistance. Inhaling feels like drinking from a fire hose.

It works the same way on the System One, Dreamstation Pro, and Dreamstation Go.

On the other hand, if I force myself to take slow, shallow breaths, there is less difference, but I can’t do that long before I have to take a deep breath.

If we ignore humidity and temperature for simplicity, the machine only knows the flow rate (measured between the filter and fan) and the pressure (measured between the fan and hose). Everything else has to be calculated as a function of those and the information we provide for the hose and mask).

[Pugsy]

edited

[RichieC]

Ok . . . . all these reply’s and I got nothing. Thanks.

[Pugsy]

Ok . . . . all these reply’s and I got nothing. Thanks.

Well actually you got the most pertinent reply with what ChicagoGranny said.
The mask is designed so that if one side of the frame gets totally blocked that the other side of the frame will compensate and keep the pressure at the desired pressure. The pressure doesn't get reduced just because the air flow doesn't make it through the frame if a person lays on their side.

What makes you think the pressure was reduced?

But I noticed when I lay on my side I lose air pressure by cutting off the air supply.

How do you know air pressure is being lost?

The mask was designed and tested so that when one side is completely blocked there is enough air pressure to the mask from the other side to maintain the set pressure.

[ragtopcircus]

I learned something today. Resistance control is indeed under mask type on the DreamStation machines.
This is new. It's not similarly noted on the System One machines.

Yeah, they just called it SYSTEM ONE resisistance.

[ragtopcircus]

Btw, I would also suggest checking the Hose Type setting, which is right next to the Mask Type setting on the Comfort menu.

[ragtopcircus]

Ok . . . . all these reply’s and I got nothing. Thanks.

Well, all of us are trying to help you, not win debates or teach engineering. So to summarize what you got so far:

1) Why do you say you aren’t getting enough air when one tube is closed (a fair question)? In other words, do you feel like inhaling takes more effort, like breathing through a straw? Is the sound of air rushing in one tube bothering you? Do you feel air-starved all the time, but it’s just a little worse on your back? Is your pressure comfortable if sitting up or on your back?

2) Is your hose type set correctly? I doubt if there is any dispute about this one.

3) Is the mask type set correctly? This one is disputed, but really, what does it hurt to check?

And some more:
4) Are you breathing entirely through your mouth, nose, or both? Do you get congested when you go to bed? Is it worse on your side?