ResScan data: Is pressure data cumulative?

apap settings for last night were: min 14.6 max 18.0 (EPR=off)

In the "Statistics" tab in ResScan the Pressure data reported was:

Median 14.6
95th percentile 16.3
Maximum 17.9


I looked at the actual detailed Pressure graph in Rescan. My pressure never went above 14.88 for the night. Even breaking down the graph into 30 minute sections, 14.88 was the maximum pressure for the entire night. Most of the night it stayed at 14.6 (the minimum).

Question: Are the 95th percentile & Maximum numbers above cumulative for previous nights, even though I have selected "1 Day" in Rescan?

Or is something wonky and I need to reboot S9?

RandyJ wrote:apap settings for last night were: min 14.6 max 18.0 (EPR=off)

In the "Statistics" tab in ResScan the Pressure data reported was:

Median 14.6
95th percentile 16.3
Maximum 17.9


I looked at the actual detailed Pressure graph in Rescan. My pressure never went above 14.88 for the night. Even breaking down the graph into 30 minute sections, 14.88 was the maximum pressure for the entire night. Most of the night it stayed at 14.6 (the minimum).

Question: Are the 95th percentile & Maximum numbers above cumulative for previous nights, even though I have selected "1 Day" in Rescan?

Or is something wonky and I need to reboot S9?

No, they are not cumulative. Wonky? Only in that the data that eventually gets displayed in Resscan does not include data generated beyond a full minute increment beginning with the start time of data recording. I've seen the same thing you are seeing.

Take a read in these topics. I explain what I have observed. That may be the explanation for what you are asking about.

viewtopic.php?f=1&t=74219&p=681202#p681091

viewtopic.php?f=1&t=73749&st=0&sk=t&sd=a

idamtnboy wrote: No, they are not cumulative. Wonky? Only in that the data that eventually gets displayed in Resscan does not include data generated beyond a full minute increment beginning with the start time of data recording. I've seen the same thing you are seeing.

Take a read in these topics. I explain what I have observed. That may be the explanation for what you are asking about.

viewtopic.php?f=1&t=74219&p=681202#p681091

viewtopic.php?f=1&t=73749&st=0&sk=t&sd=a

Thanks, idamtnboy. I read the threads you cited and understand the concept of a one minute or less drift in the beginning of recording, but it doesn't really account for a difference in reported maximum pressure that I cited above. The summary data that ResScan reported for last night almost has nothing to do with what the Detailed data shows for the same session.

However, the idea of using a virgin sd card is intriguing, and I might just reboot as well to see if anything gets reported differently.

I had been using straight cpap and just started using apap again, so I hadn't looked at reported pressures in a long time.

RandyJ wrote:Thanks, idamtnboy. I read the threads you cited and understand the concept of a one minute or less drift in the beginning of recording, but it doesn't really account for a difference in reported maximum pressure that I cited above. The summary data that ResScan reported for last night almost has nothing to do with what the Detailed data shows for the same session.

Using a newly formatted card can and does have an effect.

What I intended for you to pick up on is that often there is second by second data just before shutdown that does not get recorded to the detail data on the card because of the full minute increment method of creating edf files. I think what often happens is there is a data point in those final seconds that the S9 captures and inserts into the summary file, but does not show up in the detail data.

You are familiar with the fact that the data in the summary page comes from the summary data file and not from the detail files, right? Once in awhile I have an event shown on the event graph at the end of the session for which there is no corresponding flow graph. The flow graph recording got cut off before the event recording did. I don't put much credence into the max numbers for leak and pressure because those numbers sometimes shoot way up when I take the mask off, the recording algorithm captures them and puts them into the summary file, but they don't get inserted into the corresponding leak and pressure graph recordings because they occur after the last full minute increment of detail data.

idamtnboy -- Ok thanks for explaining that, I get it now.