SleepHead Special data wanted

[Wellie]

Hi,
Is there a way to export the tidal volume data out of Sleephead / or interrogate Sleephead files to do the same.
I experience many events during the night when the tidal volume spikes high (10-20 events per night of over 2100 ml). By using an oximetry I know this is when my oxygen level drops and as a consequence I take deep breaths, my heart going in to overdrive etc.
Anyway, I want to be able to chart these events, which I could do if I were able to extract the event info.

Many thanks in advance.

[Pugsy]

I don't think there is any way for SleepyHead to export that particular piece of data to do what you are wanting to do.
Have you looked at the Overview tab for the way that SH does the tidal volume graph?

Does anyone who happens to be proficient in ResScan special reports know if ResScan would do something like that?
All I know to do is generate the report that shows Tidal volume like this.
I never messed with ResScan all that much so I am not very adept with it.

[Wellie]

Sorry Pugsy, I should of mentioned my unit is a Respironics System One REMStar 60 Series CPAP Auto with C-Flex.

I've also looked at Encore Pro 2 (Philips), and it goes noway in to the same detail Sleeyhead does.

[Pugsy]

Yeah, Encore doesn't offer anywhere near the detail because in most situations it isn't needed.
I don't think that even with the ASV machine where the TV might be more important that it shows anything special.
If the overview graph in SH isn't sufficient to meet your needs then I don't know what to tell you.

Maybe if you will modify your subject title here in this thread to "SleepHead Special data wanted"...Mark who designed SleepyHead will see this thread and chime in with any ideas he might have to help you get what you want.
Right now he will likely just skim over it as he likely would think it is a typical question that I can normally answer.

[Wellie]

Pugsy, thank for the idea, have done so

Best regards

[Pugsy]

I also sent Mark a PM asking him to stop by here. He isn't online here everyday but eventually he will get the PM and will stop by.

[jedimark]

Hmm.. I can't remember if CSV export has the capability to dump graph data. Been so long since I've looked at that module.

Anyway, the data generated for Tidal Volume / Respiratory Rate and Minute Ventilation on Philips Respironics machines, is extracted by some experimental code I wrote to process the flow rate waveform. Basically put, each breath gets peaks, lows and midlines pre-flagged by another algorithm, then it sums the volume of the area inside the breath and the zero line considering every data point in the flow waveform within the breaths boundaries, giving the total tidal flow for each breath (times 2, because the tidal flow of breaths in minus breaths out averages out to zero, technically I can use just the absolute value of intake, exhalation, or an average of the absolute value of both, I forget which approach I took)

A lot of spikes occur because of the very low resolution of the flow rate waveform - basically during apneas, or long snore/rollover events it can send the data haywire producing the spikes, because it's either crossing the zeroline all over the place, or there is long delays without crossing the zeroline.

So the more accurate the pre-flagging is, the more accurate the Tidal Volume can be, but if there aren't reliable data points to flag, it's going to keep summing until the data gets normal again.

It's not just my algorithm that works like this, I've noticed ResMed produces similar results, but my code probably could do with better filters.

Suggestions for improvement by maths geeks are always welcome

[Wellie]

Thanks for your response but unfortunately the .csv file only details events for the following:

Event:
ClearAirway
FlowLimit
Hypopnea
Obstructive
Pressure
PressurePulse
RERA
VSnore
VSnore2

but what I want to do is extract the flow events which produce excessive spikes, i.e. from below the Tidal spikes above 2100. If I can access the data then I can filter it and build my reports - weekly, monthly trends etc

[MitzyG]

Dumb question - What does the tidal volume mean? I got the "dictionary definition" from Wikipedia, but mine is slowly going down from 700 to 660. Is this "good", "bad" or just "data"?

[Pugsy]

What does the tidal volume mean? I got the "dictionary definition" from Wikipedia, but mine is slowly going down from 700 to 660. Is this "good", "bad" or just "data"?

It's just data and there is a wide range in what is normal...and the "normal" range is much, much larger than 700 to even 600.