Multiple Sessions in One Night

[bjhughes]

I've been using OSCAR since about the time I started using my DreamMapper CPAP machine, tracking my results for each night. A few weeks ago I noticed more than a single session in one night on some occasions, the last 4-5 days it has become each night. OSCAR will show that it imported 3-4 sessions and the graphs will have gaps or breaks in them, the session lengths are random. I'm not turning the machine on and off during the night either.

I thought maybe this was caused by power glitches, the power where I live isn't the best. I hooked up a UPS a few nights ago but I still get these breaks or multiple sessions so it's not the power.

Does anyone know if this is normal or if this could be signaling an issue with the machine? I'll upload an OSCAR screenshot later tonight.

Edit: Here are two images from last night Feb 11 2020, one is zoomed into the session break:



The other graphs, like respiration rate, show breaks starting at the same time but for much smaller periods.

[Dog Slobber]

Turn ramp on.

If the machine is power cycling, you will see the machine set to ramp at the beginning of every session.

If you don't see ramp then it's likely a reporting issue.

Post a graph, we still might be able to tell if it's a power cycling or reporting issue. If at the start of sessions, your machine is above your minimum pressure then it's a reporting issue.

[Pugsy]

I have heard of some Respironics machines showing multiple sessions when there weren't multiple sessions.
Saw it first hand on a System One machine but have also seen it happen on some DreamStation machines.

Please post a detailed report of a night with multiple sessions where you know that there weren't any power interruptions.
Be sure and include the session data on the left side below the statistics.

[chunkyfrog]

How long are the interruptions?
If we know the pattern, we might be able to identify the species of alien.
Just kidding . . .

[bjhughes]

Turn ramp on.

If the machine is power cycling, you will see the machine set to ramp at the beginning of every session.

If you don't see ramp then it's likely a reporting issue.

Post a graph, we still might be able to tell if it's a power cycling or reporting issue. If at the start of sessions, your machine is above your minimum pressure then it's a reporting issue.

I'll post a graph tonight, I didn't have a chance this morning.

I do have ramp on but you have to press a button to turn it on. If the power goes out for a short time, the ramp does not come back on automatically.

[Dog Slobber]

Turn ramp on.

If the machine is power cycling, you will see the machine set to ramp at the beginning of every session.

If you don't see ramp then it's likely a reporting issue.

Post a graph, we still might be able to tell if it's a power cycling or reporting issue. If at the start of sessions, your machine is above your minimum pressure then it's a reporting issue.

I'll post a graph tonight, I didn't have a chance this morning.

I do have ramp on but you have to press a button to turn it on. If the power goes out for a short time, the ramp does not come back on automatically.

OK, we might be able to tell if the machine is power-cycling by where the pressures are at session starts.

[Pugsy]

Legitimate power disruptions will show up on the graphs as breaks in therapy...even if very brief.

Multiple sessions being reported without breaks in the graphs....there's a problem somewhere in the sensors or the writing to the SD card.
We've never figured it out.

3 or 4 false session startings probably not a big deal but I have seen reports where it shows 40 to 50 different sessions with zero breaks in the therapy graph lines.....obviously not normal.
I am thinking a problem writing to the SD card...not normal and anything not normal makes me question the other data that I am seeing.

I would definitely keep a close eye on things....something may be starting to fail inside the machine when you see multiple sessions and no breaks in therapy graph lines.

[bjhughes]

Okay, I've uploaded some images from OSCAR, it looks to me like the machine wasn't recording data for the periods that terminate the sessions. The graph shows the normal pressure but the EPAP reading, from the Flex, is missing. The other graphs all show a break in readings at the same time, although they are pretty short duration.

[Pugsy]

It's the multiple session bug.
Note the time that one session ends and the next session begins....they are the same time but there is no real break in the therapy line.
Software bug in the machine itself and conveying that to the SD card and likely explains why there is a break in the green exhale line and not on the red inhale line.
Encore Pro would show you the same thing. It's not related to OSCAR/SleepyHead.

I don't know of any way to fix it because we don't know exactly what is causing it..
Some people have elected to just live with it and if it doesn't get any worse than this there probably is no urgent reason to fix it but it is not normal and it means something screwy is going on inside either the machine or the software writing to the SD card.
But I have seen it list 50 sessions in one night and the person didn't lose power or turn the machine off and it does a number on the SD card because each session starts a new file on the card and the P0 folder will get full in about a week instead of 5 or 6 months.

[bjhughes]

It's the multiple session bug.
Note the time that one session ends and the next session begins....they are the same time but there is no real break in the therapy line.
Software bug in the machine itself and conveying that to the SD card and likely explains why there is a break in the green exhale line and not on the red inhale line.
Encore Pro would show you the same thing. It's not related to OSCAR/SleepyHead.

I don't know of any way to fix it because we don't know exactly what is causing it..
Some people have elected to just live with it and if it doesn't get any worse than this there probably is no urgent reason to fix it but it is not normal and it means something screwy is going on inside either the machine or the software writing to the SD card.
But I have seen it list 50 sessions in one night and the person didn't lose power or turn the machine off and it does a number on the SD card because each session starts a new file on the card and the P0 folder will get full in about a week instead of 5 or 6 months.

Thanks, that's good to know. I looked at the data from last night and there was only a single session break. If I start getting a large number of them in one night, I'll contact my doctor first and ask if it's an issue. If he's concerned I can contact my DME.