SleepyHead VS2 scores - (the numbers in parentheses in the Event listing)

[Roncador]

I am probably reinventing the wheel here but as I have seen quite a few posts in various apnea forums where this (number) is discussed without any firm or definite conclusions that I could find (many appear to assume the (xx) is "seconds duration") I decided to share my own investigate conclusions with the board. Please feel free to criticize, supply further info, or just tell me to shut up! After all, that's what we're all here for - to learn from each other's experiences :-)

I have found that in the SH Event report the "Vibratory Snore (VS2) xx events" TITLE line the "xx" value signifies the number of 2-minute windows when a snore began to be detected - and you will more than probably see more than one entry/window line per session.

Besides this if one snoring episode lasts continuously for more than 2 minutes then you will see multiple event lines to report this "happening", such as:
...
03:11:18 (5)
03:13:18 (12)
03:15:18 (4)
...
This will keep on happening for as long as you keep snoring!

The number in parentheses is the number of snoring occurences that took place during a 2-minute window.
So in the small extract shown above I snored 21 times in the period from 03:11:18 thru 03:15:17.

This interpretation of the (SH VS2 parentheses number) was verified in a Respironics Encore Pro report by checking out the graph entitled "Flow Limitation And Vibratory Snore Indices".

In this graph the "Vibratory Snore Index is the total number of vibratory snoring events per night divided by the hours of use" (explanation from Encore Pro Help File).

A typical (bad) example of my session was: 64.7 index X 6.48 hours use = 419.256 events.

Adding up all the numbers in parentheses in the SH VS Event listing came to a total of (419).

I painstakingly repeated these calculations for over 60 different nights' data and the result was ALWAYS a direct AND COMPLETELY ACCURATE correlation between the SH VS2 parentheses numbers and the Encore VS Index number.

That is to say, the Encore "Average VS Index" = (sum of SH VS2 numbers in brackets) / Usage Time

Now that I'm reasonably confident about WHAT the numbers signify, and so how to interpet them, I am now embarking on a "how to reduce them" investigation - pressure, humidity, ramp, sleeping position, soft medication, etc - any thoughts on this matter would be most welcome!

BTW: Data from Dreamstation CPAP Pro

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Correction: the time duration should have read: "03:11:18 thru 03:17:17."

[Walla Walla]

From what I've seen the VS2 data unlike the VS data on the DreamStation is pretty much useless. It picks up everything from sheets rustling to the clock ticking. To eliminate it I just turn it off in SleepyHead.

[OpalRose]

Hi Roncador,
I personally turn the VS2 data off, but I can tell by your post that you really like to analyze this type of data so here is a link to Snoring Data from the Beginners Guide to SH.
http://www.apneaboard.com/wiki/index.php...oring_Data

VS data only shows if your are using APAP mode, but you are using a DreamStation Pro, so all you can see is VS2 data.  Mabye the above link will shed some light and answer some of your questions.

[Roncador]

From what I've seen the VS2 data unlike the VS data on the DreamStation is pretty much useless. It picks up everything from sheets rustling to the clock ticking. To eliminate it I just turn it off in SleepyHead.

Now sure how it could do that - rustling and ticking - on my DreamStation. There is no microphone involved, it counts VS2 based on flow rate data.

From the Wiki article on snoring:
"How does a CPAP machine detect snoring?
CPAP machines do not have microphones attached to them. So your CPAP is not listening to the sound of your snoring. So how does it actually detect snoring? It analyzes the Flow Rate data."

But I am also basing, to some extent, my belief in the (numbers) being reported on a quite reliable secondary recording-of-incidents source  - THE WIFE!

If she is awoken at any time by my snoring she just presses a button and the time is recorded on the laptop. If the snoring continues (wasn't just a quick snort) she presses again, and again ...

This enabled me, to some extent, to check the relative accuracy of all the VS2 Events shown in SleepyHead - and also to be able to complain to the wife that she wasn't doing the job properly!!!

Yes, I AM a retired Computer Engineer, and Yes, I DO have an activator button and small circuit board wired to the USB port on the laptop. Overkill? Maybe so, but it keeps the grey matter active!

---

Hi Roncador,
I personally turn the VS2 data off, but I can tell by your post that you really like to analyze this type of data so here is a link to Snoring Data from the Beginners Guide to SH.
http://www.apneaboard.com/wiki/index.php...oring_Data

VS data only shows if your are using APAP mode, but you are using a DreamStation Pro, so all you can see is VS2 data.  Mabye the above link will shed some light and answer some of your questions.

Hi OpalRose,
I had already studied this Wiki article - and many others from diferent sources.

I would draw your attention to the following phrase in the Wiki article:

"VS2 snores are recorded by all Philips Respironics machines. They have both a time stamp and a "magnitude" number attached to them. In the SleepyHead list, when you look at the detailed information for each VS snore event, there will be a NON-zero number in the in parenthesis for that event. Whether that number represents the length the snoring went on or some kind of measure of the loudness of the snoring is anybody's guess. We really do not know the significance of that number."

The point that I was making in my post (maybe not TOO clearly) is that I believe that I have discovered the significance of the number!

After totalizing the (parentheses numbers) in the VS2 Event entries for more than 60 days of data and comparing them to the Encore Vibratory Snore Index it CANNOT be coincidence that the numbers agree almost down to a second decimal point.

My assertion is that each (number) represents a snoring event during the corresponding 2-minute window and is NOT length or loudness. This is not a "guess" - it's based on statistical observation of 2 months of data.

I've just now calculated last night's snores:  
Sleepyhead: 34 VS2 events with a total of 98 in parentheses / 5.66 hours = 17.31 per hour
Encore: Vibratory Snore Index = 17.3

I rest my case :-)

Of course, to quote Disraeli: "There are three kinds of lies: lies, damned lies, and statistics." ;-)

[OpalRose]

My question is what are you going to do about the snores? If your machine is set with an optimal pressure, you shouldn't experience that many snores.

The data from your graph also suggests a positional sleep problem. In other words, were you sleeping on your back during the 4 to 5 time frame?

You may want to try raising your pressure a little at a time, until you see a decrease in the apnea events. Just a suggestion.

[Roncador]

The data from your graph suggests a positional sleep problem.  In other words, were you sleeping on your back during the 4 to 5 time frame?

You may want to try raising your pressure a little at a time, until you see a decrease in the apnea events.  Once your cpap is set to take care of those events, you really
shouldn't experience that many snores.

Thanks for the advice, OpalRose :-)

I'm currently going thru various options to try and reduce the AHI and Snore figures.

BTW, I never sleep on my back.

[Walla Walla]

Yep your right about VS2 not picking up sheets and clocks. But than my pressures are above 16cm so the snore detection is disabled anyway.

Since I'm not the sharpest knife in the drawer maybe you can explain to me how the VS2 detection will improve my sleep apnea treatment?

[TBMx]

don't let them discourage you - you are not alone!

http://www.apneaboard.com/forums/Thread-...P-machines

I guess the whole "VS2 is meaningless" can now be put to rest - once and for all

Nevertheless I would really be interested what you think about the actual presentation of that data?
I mean it is pretty clear that the VS2 markers have no "extra" meaning - they just clutter up the screen. (or do they not?)
As far as I understand the very same information is already presented in the snore-graph.

Obviously VS2 differs to VS, as VS2 gets scored long before VS. Meaning: if the snoring itself is severe enough it gets scored as an VS event. If it is not that severe but still "vibrational snoring" it counts towards the VS2-Value in this 2 minute window.

I have a very different machine, which does the very same or at least something equal. It also "thinks" in ~2 minute windows. My machine has "epochs with snoring" - if enough snores are detected within this 2 minute-window, it gets flagged as "epoche with snoring". (As my machine decides that threshold based on the current pressure, that threshold should or needs to be user definable in the settings.)

Would you consider that kind of "presentation" as an "plus" in information. Or HOW would you present that kind of data - or omit it (as it seems to be the current suggestion.)

[OpalRose]

Roncador,
I was looking for this older thread on VS and VS2 snores....found it. Thought you would find it interesting.

http://www.apneaboard.com/forums/showthr...?tid=18479

[Roncador]

Since I'm not the sharpest knife in the drawer maybe you can explain to me how the VS2 detection will improve my sleep apnea treatment?

It won't, but I have to explain what's happening ...

The thing is that all this CPAP stuff started because of a serious snoring problem where my GP referred me to a sleep lab. Result was an apnea diagnosis and the use of the DreamStation.

One year later I now appear to have more or less sorted, or at least greatly reduced, the apnea problem - last month shows an average AHI of 3.7 with a maximum about a month ago of 14.27 (see enclosed Encore graphs). But ...

the snoring problem is still causing serious family problems :-(

Neither my daughter nor my sons will let me sleep over if I go to visit them - they live 6000 miles away - which I try to do every 6 months together with my wife.

Because of my snoring my wife had moved into a separate bedroom and only recently came back to help in an attempt to sort out the problem by monitoring my sleeping pattern with our DreamStation and support laptop setup.

So I have been trying to understand the various VS reports to at least have a handle on the extent of the problem - the first step to being able to evaluate measures that could reduce the problem.

So, to answer your question directly, no - the VS numbers don't help with the apnea, but certainly might help with the original, and to my family, more serious problem of snoring.

Of course, I am already experimenting with "solutions" for the snoring problem - nose patches, medication, etc, etc, etc - but I wanted to see if I could apply CPAP VS statistics to help analyse the success, or not, of the various solutions. So the first step was to try and understand, and interpet, the numbers that were available.

Wish me luck!