SleepyHead and snore data

[tetragon]

What is the difference between Vsnore and the snore graph in SleepyHead (other than the number is 0 and the graph is graphy)? I'm running off of a git pull from earlier this evening, but I also saw the same 0 and graphiness with pre-built 0.8.6.

Notes on the graphs: The leak line in this night is not normal for me, it is normally much lower. The short duration of the night is not due to using the machine for part of the night, it is due to sleep restriction. The red horizontal line segments are just the 150 logged pressure pulses merging together.

[robysue]

The System One Autos and Auto BiPAPs record two kinds of Vibratory Snores when they are running in Auto Mode: One that shows up only in the tick marks in Encore Viewer (and Pro) and one that shows up in both the wave form data in Encore Pro and the tick marks in Encore Viewer (and Pro). This second kind of Vibratory Snore is used to increase the pressure on the Auto machines. When the Auto machines are run in fixed pressure mode, the vibratory snores of that second type---the ones that show up on the wave form---are simply not recorded. Just like Flow limitations are NOT recorded when the machine is running in fixed pressure mode. The machines that only run as fixed pressure machines, like yours, also do not record any Flow Limitations or any of the Wave Form Vibratory Snores. As to why PR made this choice to not record that data when a machine is running in fixed mode, your guess is as good as mine.

Now to get back to your question: SleepyHead's Vibratory Snore index (the thing that is 0.0 in your report) only counts the Vibratory Snores that show up in the the Wave Form in Encore Pro. Since your machine is always running in fixed pressure mode, it simply does not record this data. Hence the index is always 0.0 because there are always 0 such events. Likewise, that's why your Flow Limitation Index is also 0.0 night after night. And I bet that if you zoom in on the breaths--as in seeing each individual breath, you'll see examples of breaths that are indeed characteristic of Flow Limitations, but are not flagged as such simply because your fixed pressure machine is just not bothering to record them as such.

Now for the Snore Graph. Obviously this graph is somehow built from the data that DOES show up in Encore Viewer (and Pro) as VSI tick marks, but does not show up as overlays to the Wave Form data in Encore Pro. Now I have no idea how Jedimark chose to graph that data as a curve instead of tick marks. I would assume that the larger the number, the more serious the snoring. But whether it indicates loudness or the frequency of snoring breaths is something that I'm not sure anybody knows for sure since there seems to be mighty little official information about just when a VSI gets scored as a Wave Form VSI (in Auto mode) and when a VSI gets scored as a "tick mark only" VSI (in both Auto mode and fixed pressure mode.)

[robysue]

And here's an example illustrating what I mean by how the snore data looks in Encore Viewer compared with Sleepy Head. Note that on this night my machine was set in fixed pressure mode with IPAP = 8 and EPAP = 6. You can see that I hit the ramp button 5 times that night (with a long ramp of 45 minutes): In the Encore Viewer data, the slanted lines in the pressure graph are the ramp periods. They show up as square waves in Sleepy Head's version of the pressure data.

Note that the VSI indices are very different in the two programs. Also note that all the VSI ticks in Encore Viewer show up at exactly the same places where there is visible "snoring" going on in the Sleepy Head graph.

Here's Encore Viewer's view of the night:


And here's Sleepy Head's view of the same night: