Ramp Function on Respironics Dream Station

I'm trying to understand my OSCAR data and the first thing I observe is that what I expected to be in ramp doesn't correlate with the recorded pressures.
My Dreamstation (500X110) is set to AutoCPap mode with a Linear Ramp Pressure of 4.0 and a ramp time of 30 minutes.
My expectation is that machine would begin (at turn on) with a pressure of 4.0 and would hold that pressure for 30 minutes, whereupon the ramp would expire and control of the pressure would be then guided by events.
What OSCAR's pressure graph is reporting to me is that at startup the pressure is set at 8.00 (red trace) and the EPAP (green trace) is 6.0.
Shouldn't one or another of these be 4.0 ?
OTOH, perhaps my assumptions of what the ramp pressure, time and linearity are incorrect.
Can someone help?

Have you actually pushed the ramp button to start it?
With Respironics machines it takes more than just turning it on in the set up menu. You have to push the ramp button to start it as well.

dataq1 wrote: ↑

Mon Oct 04, 2021 8:43 am

My expectation is that machine would begin (at turn on) with a pressure of 4.0 and would hold that pressure for 30 minutes, whereupon the ramp would expire and control of the pressure would be then guided by events.

Smart ramp only will do this.

Regular ramp starts at 4 and takes 30 minutes to gradually move up to the minimum starting pressure.

dataq1 wrote: ↑

Mon Oct 04, 2021 8:43 am

What OSCAR's pressure graph is reporting to me is that at startup the pressure is set at 8.00 (red trace) and the EPAP (green trace) is 6.0.
Shouldn't one or another of these be 4.0 ?

No, not unless you actually pushed the ramp button.

Oh My !
I've been assuming the ramp starts when the machine is first turned on, and could be reinitiated by pressing the ramp button (say during the night).
Here I've been doing it wrong for almost 20 years !!!
There is a "smart ramp" function ?

dataq1 wrote: ↑

Mon Oct 04, 2021 9:43 am

There is a "smart ramp" function ?

ResMed machines don't have a separate ramp button to push but Respironics have always had one. Didn't matter what you had it set to in the setup menu it wouldn't start without pushing the ramp button separately.

Yep...tied to when the machine thinks you are asleep...but you still have to push the ramp button.
I didn't include regular ramp explanation in this image but all this is available in the clinical/provider manual (not in the user manual)

Smart ramp is sort of complicated (ResMed offers something similar) IMHO and tied to the machine assuming someone is asleep. I am from Missouri and I want "Sho Me" or proof and I haven't ever seen proof that the machine can tell asleep from awake breathing. If they could do that then they wouldn't/shouldn't have so many false positive awake breathing flags. So I consider it "fluff".

I will try that experimentally (with a clean SD card and different Oscar profile)
Let you know what happens when the start bars is pushed followed by the ramp bar and the patient (me) is awake breathing!
I'm always up for experiments!