01-20-2020, 03:06 PM
(This post was last modified: 01-20-2020, 03:12 PM by ragtopcircus.)
RE: correct setting with n20,n30 or n30i
DaveL, the pressure sensor is in the machine, NOT the mask. In other words, it is measuring pressure at the wrong end of the hose. There is pressure drop in the hose and mask proportional to the airflow. When you are between breaths, the mask compensation does nothing. When you are inhaling and exhaling, it tells the machine how much to adjust its internal pressure so that the pressure you experience in the mask matches the target pressure.
Try breathing through a drinking straw. Feel the restriction? The purpose of mask compensation is to dynamically adjust the pressure at the other end of the "straw" in response to airflow. When properly adjusted, you won't feel the restriction.
01-20-2020, 03:13 PM
(This post was last modified: 01-20-2020, 03:22 PM by DaveL.)
RE: correct setting with n20,n30 or n30i
Laughing....So it's a fudge factor to attempt to get the right flow at the mask based upon the pressure set at the machine.
Darn engineers. (I'm an engineer...fwiw.)
There are so many masks. How the heck do you get the air into the wearer when there are so many restrictions in the way? I mean this all in a respectful way. I understand settings...
( I had my first cpap for 8-1/2 years. I had my first cpap mask for 5 years. A "Breeze" if I remember right. Compliance was wear the thing for at least 4 hours every day. My machine had an "hour" reading.That's all my sleep doc needed. Proof it was turned on enough hours for the number of days between appointments. If I wasn't compliant he would pull my driving license away.)
I'm so grateful to be a participant here. It makes such a great difference in my sleep treatment and sleep quality.
01-20-2020, 03:30 PM
(This post was last modified: 01-20-2020, 03:31 PM by ragtopcircus.)
RE: correct setting with n20,n30 or n30i
It's load characterization for open-loop control, but yes, it's a fudge factor.
RE: correct setting with n20,n30 or n30i
(01-20-2020, 03:06 PM)ragtopcircus Wrote: DaveL, the pressure sensor is in the machine, NOT the mask. In other words, it is measuring pressure at the wrong end of the hose. There is pressure drop in the hose and mask proportional to the airflow. When you are between breaths, the mask compensation does nothing. When you are inhaling and exhaling, it tells the machine how much to adjust its internal pressure so that the pressure you experience in the mask matches the target pressure.
Try breathing through a drinking straw. Feel the restriction? The purpose of mask compensation is to dynamically adjust the pressure at the other end of the "straw" in response to airflow. When properly adjusted, you won't feel the restriction.
Think of a dryer hose...the one that vents to outside.
The simplest ones are corrugated on the inside. Lots of restriction.
Longer the hose the more the restriction.
More restriction, less flow.
So on my cpap, I put on a thermal hose. That's a change. Restriction? Then I buy a mask that has a converter and a length of short, very flexible, smaller corrugated hose added on. Restriction. And my mask comes with one of a Kazillion different shapes.
Those are reasons that I would like a much better machine than my cpap. I'd like a machine that can autotitrate when I make a change. I haven't bought one yet. I'll look for a used one. Hope I can find one.
01-20-2020, 03:37 PM
(This post was last modified: 01-20-2020, 03:38 PM by ragtopcircus.)
RE: correct setting with n20,n30 or n30i
Well like I said, the ultimate test of the fudge factor is how much the mask moves as you breathe, and how comfortable you are.
Fwiw, pressure drop data for masks can be found in the back of their user manuals. Pressure drop data for several hose types/sizes can usually be found in the back of the machine manuals. Unfortunately, the manufacturers do not publish the specs for their mask compensation settings, but it can be inferred. However, they do lump a lot of masks together in just a few setting options.
RE: correct setting with n20,n30 or n30i
(01-20-2020, 03:37 PM)ragtopcircus Wrote: Well like I said, the ultimate test of the fudge factor is how much the mask moves as you breathe, and how comfortable you are.
Fwiw, pressure drop data for masks can be found in the back of their user manuals. Pressure drop data for several hose types/sizes can usually be found in the back of the machine manuals. Unfortunately, the manufacturers do not publish the specs for their mask compensation settings, but it can be inferred. However, they do lump a lot of masks together in just a few setting options.
Thanks.
The old KISS principal...keep it simple....
RE: correct setting with n20,n30 or n30i
So... where do we stand as far as the correct setting for the dreamwear nasal mask using the ResMed autoset, nasal or pillow setting?
RE: correct setting with n20,n30 or n30i
Try out Nasal to see if that suits. If not, then go Pillows.
Mask Primer
INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEBSITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
RE: correct setting with n20,n30 or n30i
Thanks a lot for everyone who responded.
RE: correct setting with n20,n30 or n30i
I had the same question and did some research. The pillows setting would be for a mask such as the N30i or P30i--actual pillows under the nose. The nasal setting is for a mask that covers your whole nose such as a Wisp or N10 mask. The full face setting of course is for a mask that covers both your nose and mouth or something like an F30 or F30i.
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