Mask pressure vs. pressure in SH

[old dude]

Sleepyhead shows a max pressure on the left side in the statistics section that seems to only correspond with the maximum pressure shown in the Mask Pressure graph. It's always a couple of cm higher than the max shown in the "plain" pressure graph and doesn't seem to be related to figures actually produced by the machine.

How is this number generated and which is the true and correct pressure actually reached by the machine? Is it the max pressure shown in "statistics" and the "mask pressure graph", or is it the highest pressure shown in the "pressure" graph?

Why are there two graphs?

[Pugsy]

The "pressure" graph shown in SH reflects the pressure on exhale so if you are using exhale relief it's not going to reflect the max or IPAP. It's always going to look like it isn't reporting the actual pressure when exhale relief is used. It is reporting a line for exhale pressure.
This had me confused at first also..thought whoa what's going on .

Mask pressures shows inhale and exhale and if you were to zoom in real close you can see both.

[old dude]

Ah, OK I see.

Therefore, if one were concerned with knowing an accurate reading of the max pressure the machine reached on a given night (and was using EPR), mask pressure would be the more accurate graph then.

[Pugsy]

Yeah...mask pressure shows both and is accurate visually.

Regular pressure line is accurate for exhale but you have to mentally add the exhale relief to the numbers to get inhale pressures.

Once you wrap your head around it then it's not so confusing.
Like if the max my inhale went to 11...the regular pressure line will show 8 as where it went to since I use EPR of 3
The statistics on the left side are accurate...but the regular pressure line reflects exhale pressures only and not inhale.

Use to be we saw 2 lines on the regular pressure graph..one for inhale and on for exhale. Not sure why it changed unless it has to do with the AirSense machine recording differently and thus SH reports differently.
There doesn't appear to be any setting in SH that I might have changed accidentally to account for the exhale only line that I can find.

[JimW159]

My SH displays the Pressure graph as two parallel traces - red for pressure and green for exhalation pressure (EPAP) separated by the EPR value. As one moves the green time line across the graph the trace's legend (upper left above the trace) displays the pressure and EPAP pressure at the point in time at intersection. e.g. Pressure 15.22 EPAP 12.22 (if one has EPR set as 3). However, the trace that confuses me most is "Time at Pressure" for the life of me I cannot figure it out and I can find no reference to it in the documentation I have found. Any help there?

[Pugsy]

My SH displays the Pressure graph as two parallel traces - red for pressure and green for exhalation pressure (EPAP) separated by the EPR value

And mine doesn't and I can't for the life of me figure out why. See image below.
Time at pressure was just something added at the last minute as an afterthought so no real documentation.
Mainly it's just a graph that shows you approx how much time you spent at each pressure when using auto adjusting pressures.

[BlueDragon]

My SH displays the Pressure graph as two parallel traces - red for pressure and green for exhalation pressure (EPAP) separated by the EPR value

And mine doesn't and I can't for the life of me figure out why. See image below.

Displaying EPAP (green) and/or Pressure (red) in the Pressure graph is an option. Maybe you turned your pressure graph off at some time? (Click on Pressure title, select Plots...)

[JimW159]

My SH displays the Pressure graph as two parallel traces - red for pressure and green for exhalation pressure (EPAP) separated by the EPR value

And mine doesn't and I can't for the life of me figure out why. See image below.

Displaying EPAP (green) and/or Pressure (red) in the Pressure graph is an option. Maybe you turned your pressure graph off at some time? (Click on Pressure title, select Plots...)

As stated above, if you right click in the left hand box containing the trace lable "Pressure," you can open up the dialog box labeled "Plots" and check the box you find unchecked. Both traces should immediately appear.

[Pugsy]

right click in the left hand box containing the trace lable "Pressure," you can open up the dialog box labeled "Plots" and check the box you find unchecked. Both traces should immediately appear.

Hot damn. That's where I must have accidentally messed up and only had EPAP checked.
I don't know how or when it happened but that fixes things.

Thank you both for telling me how to fix it. Wasn't the end of the world for me but it was annoying.

To old dude...do that and your regular pressure graph will show you visually your max IPAP that you were wondering about. It's a lot easier to see visually than the scrunched up mask pressure.

[old dude]

right click in the left hand box containing the trace lable "Pressure," you can open up the dialog box labeled "Plots" and check the box you find unchecked. Both traces should immediately appear.

Hot damn. That's where I must have accidentally messed up and only had EPAP checked.
I don't know how or when it happened but that fixes things.

Thank you both for telling me how to fix it. Wasn't the end of the world for me but it was annoying.

To old dude...do that and your regular pressure graph will show you visually your max IPAP that you were wondering about. It's a lot easier to see visually than the scrunched up mask pressure.

Holy smokes, thanks Jim and BD. And you too Pugsy.

Only problem is that if you back up and click on a previous date where you used a different machine (PRS1 in this case) the graph loses the IPAP line you just added and you have to go back and do the process over again. No biggie.

[Pugsy]

Well at least it's fixable and you probably won't always care once all this stuff gets to the boring stage.
I am lucky if I download once a month and even then I only look at the most recent night and then just barely.