What does VS actually measure?

Recently my PR DreamStation ASV machine has been reporting VS values in the range or 20-30 per hour. Increasing pressures correlates with increasing VS values, decreasing pressures lowers the VS values reported. Prior to this increase, my reported VS values were in the range of 0 - 3 per hour.

What is actually being measured as opposed to what is meant in terms of sleep apnea?

I’ll base my answer on knowledge I’ve gained on another apnea based forum and a free report program for obtaining your detailed sleep session info that’s called OSCAR.

As I recall, VS is referring to a measurement called vibratory snore.

Thank you for your kind reply. I apologize for not being clear enough in my question.

Please let me clarify my question. Indeed the Respironics systems do label this variable as “Vibratory Snoring.” What I don’t understand is what the machine is actually measuring when it reports this. For example, it might be measuring a rapid but shallow variation in the air pressure caused by some anomaly in the patient’s airway. It might be measuring a certain kind of audio signal, etc.

It is my understanding that actual snoring is a result of a partial collapse of the airway and that rapid opening and closing causes the sound others refer to as ‘snoring.’ In my case, this value for many years was reporting in the range of 0-3 events per hour. Then, starting in August or September, the value began a rather rapid increase over a period of several days until settling around a value of ~20 events per hour. VS and also Hypopneas should normally respond to an increase in EPAP. I tried that, increasing my EPAP upwards by a few cmH2O. Instead of seeing a decrease as expected, the VS number increased by 50% to about ~30 events per hour. Reducing the EPAP value back to the former value dropped the VS number back to the ~20 or so.

Hence the question of what is actually being measured?

OK gotcha. I’d tend to think as you on that, as in the snore vibrations are felt and measured by your xPAP. And likewise an EPAP increase should have addressed it.

Since it sounds like it didn’t, there’s a thing called positional apnea, this isn’t necessarily back vs side sleeping. I’m actually thinking in this that maybe when you’re sleeping, chin tucking is going on. By this I mean your chin and head are pointing towards your chest and therefore restricting your throat. On the other apnea site I’m on, we suggest a soft cervical collar worn just tight enough to restrict chin tuck.

Thanks, I wear a cervical collar every night. It stops jaw drop when my facial muscles relax with sleep. I hadn’t ever thought of the effects of the head tilting forward.
Thank you so much.

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