Encore Analyzer Variable Breathing Poll

-SWS wrote:James, were you ever able to correlate your VB to one more than the other: 1) your CSDB, 2) your extreme nasal and airway impedance problems, 3) other?

Well I have always had that VB range even before the nasal problems so it wouldn't appear to be related to that. Its not really possible for me to know for sure about the other factors.

jskinner wrote:

-SWS wrote:James, were you ever able to correlate your VB to one more than the other: 1) your CSDB, 2) your extreme nasal and airway impedance problems, 3) other?

Well I have always had that VB range even before the nasal problems so it wouldn't appear to be related to that. Its not really possible for me to know for sure about the other factors.

Interesting. One of my long-running theories is that perhaps Respironics had been using the VB statistic as a part of an in-house epidemiological study to help indirectly ascertain the prevalence of CSDB.

Also noting that Den, who has fluctuating and at times even high VB, fares better with CPAP modality than APAP. And that CPAP is generally the more CSDB-friendly modality of those two. But I think Den's APAP issue had to do with chasing snore rather than inducing a higher AHI at elevated pressures.

-SWS wrote:

Wulfman wrote:I've wondered if it has something to do with the REMstar Auto's algorithm, but then it's also being logged in the data-capable CPAP machines.

I've sure vacillated back and forth regarding this clue as well. My take is that the entire SQL data set was designed for APAP. Then a year or two later that APAP machine with SQL data set served as the foundation for the very first data-capable CPAP machine. A cost-effective design approach would be to just stub off the APAP treatment algorithms, but not the detection algorithms to make that data-capable CPAP.

At that hypothetical point there's no cost incentive to take the extra steps to remove VB from the SQL data set. But that also implies that VB as a statistic is accumulated in the breathing detection routines---and not as the VB control layer itself is setting flags or timers as it executes (although it's possible the stubbed routine simply sets the VB flag and/or maintains VB timers in the case of CPAP).

I'm guessing that the only potential usefulness we may be able to ascertain from that ambiguous VB statistic is whether something very wrong in health or sleep can be inferred when VB is commonly very high, as in dllfo's case. Browser's upcoming sleep study may shed more light.

There were discussions back in 2005 regarding the Pro 2 and Auto and questions arose as to just how many differences or similarities there may actually be in their design/construction......maybe only a chip or two (or sensor). I know Doug (dsm) has pictures of the Auto on his website, but I don't recall anyone having comparing the "guts" of the two machines and reporting the similarities or differences.

I keep coming back to what the causes of VB may be......breathing changes during dreaming (REM or other stages), deep sleep stages, and other health issues....COPD, etc.?

I also haven't had a chance to read the links that Doug posted pertaining to the patents, but I'm not sure they'll be all that revealing.

Den

-SWS wrote:

Wulfman wrote:

-SWS wrote:Ozij, I was going to make a funny comment about your helicopter post... but the helicopter took off! Also, I need to come clean that there are no hotdog stands at the top of that mountain.

Maybe you haven't checked enough mountains......
There are lots more mountains out here. Maybe you'd better come out and check them before ruling out hotdog stands being on mountain tops.

Den (thinking that strange posts deserve equally strange responses)

Yeah, I guess that doesn't make much sense without the deleted post or some background to go by. Ozij had humorously and correctly mentioned that helicopters can't make it to the top of the highest-altitude mountains. Those would be the mountains without the picnic tables and hot dog stands up top.

I agree that the short mountains can have hot dog stands, and the alluring foot hills will probably have walk-up Dairy Queens. Heaven knows what culinary fast-food delights are waiting for us in the strange canyons.



[on edit- ozij typed a great explanation as I was typing this reply--thanks for reinserting that, ozij!]

Sorry of the avalanche of misunderstandings that I seem to have caused....
-SWS, we've been together on this forum long enough to know that neither you or I would be humurous about the loss of human life. I had actually meant that original post to be an off topic PM - by something must have caught in my thinking beanie's rotors yesterday...

OK. Back to the VB topic.
Good point Den, I hadn't even thought, when you reported your VB, that you weren't on Auto.

-SWS wrote:I've sure vacillated back and forth regarding this clue as well. My take is that the entire SQL data set was designed for APAP.

I don't think that's quite the reason, sinced the fixed pressure machines do not report flow limitations, which the APAPs do....
Curiouser and curiouser.

Why use VB in a fixed pressure machine, and ignore flow limitations?
What about a CFLEX level VB correlation?

-SWS wrote:One of my long-running theories is that perhaps Respironics has been using the VB statistic as a part of an in-house epidemiological study to help indirectly ascertain the prevalence of machine-related CSDB.

Well VB has been there from way before the CSDB first paper was published, and an epiedmiological study does need a population...

O.

-SWS wrote:

jskinner wrote:I always have tended to have a high VB value. Typically between 50-60%

James, were you ever able to correlate your VB to one more than the other: 1) your CSDB, 2) your extreme nasal and airway impedance problems, 3) other?


Ozij, I was going to make a funny comment about your helicopter post... but the helicopter took off! Also, I need to come clean that there are no hotdog stands at the top of that mountain.

Also, I'd like to link to a relevant side discussion between georgepds and dsm:
viewtopic.php?f=1&t=36442&start=45#p316526

SWS,

This link is far more useful re VB and what it means - it is written by the people who developed the Respironics Auto that it is scored on

viewtopic.php?f=1&t=36412&st=0&sk=t&sd= ... 90#p316599

DSM

#2

If anyone reads right through the patent info it tells us a number of things - these are my interpretations & am happy to debate hem ...
1) VB is not an event as such but is identified as erratic breathing.
2) The patent writers imply that when it is detected they seek to revert back to the situation before it was detected
3) The machine reverses pressure at a max rate of 0.5 CMs per min until the VB goes away or 2.0 CMs is reached


So, If VB doesn't go away the machine goes back to the pressure that it was at before it was detected & stays there for 15 mins

So what I see is that VB is a destabilizing state of erratic breathing that in turn destabilizes the Auto Controller & thus rather than trying to treat it the machine tries to avoid it.

DSM

ozij wrote:-SWS, we've been together on this forum long enough to know that neither you or I would be humurous about the loss of human life..

Agreed. But I couldn't remember exactly what you had cited. Only a preliminary glimpse of something about a helicopter not working at high altitudes... and then literally out the door I went. But thanks for clearing that up.

ozij wrote:

-SWS wrote:One of my long-running theories is that perhaps Respironics has been using the VB statistic as a part of an in-house epidemiological study to help indirectly ascertain the prevalence of machine-related CSDB.

Well VB has been there from way before the CSDB first paper was published, and an epiedmiological study does need a population...

I still entertain that theory for several reasons. The first reason is that the CSDB patient population didn't crop up in 2005 with that twenty-some-percent or higher prevalence rate. They were always there to be observed. And who would have spent more time than anyone else observing that pressure-induced AHI rise, than the APAP manufacturers themselves? I'm fairly certain that would have been an easy pressure-versus-AHI epidemiological trend for the manufacturers to observe as they designed and tested.

Recall that industry-favored statistical 10cmH2O command-on-apnea demarcation? The APAP industry long before 2005. Recall those Resmed A10 marketing talks about not responding to hypopneas to avoid what they called "runaway" hypopneas? Long before 2005. There were a few other medical white papers describing those pressure-induction trends before 2005, but not explicitly identifying it as a third phenotype called CSDB. That all makes for the Vb statistic to have been handy long before 2005 IMO.

dsm wrote:SWS,

This link is far more useful re VB and what it means - it is written by the people who developed the Respironics Auto that it is scored on

viewtopic.php?f=1&t=36412&st=0&sk=t&sd= ... 90#p316599

DSM

#2

If anyone reads right through the patent info it tells us a number of things - these are my interpretations & am happy to debate hem ...
1) VB is not an event as such but is identified as erratic breathing.
2) The patent writers imply that when it is detected they seek to revert back to the situation before it was detected
3) The machine reverses pressure at a max rate of 0.5 CMs per min until the VB goes away or 2.0 CMs is reached


So, If VB doesn't go away the machine goes back to the pressure that it was at before it was detected & stays there for 15 mins

So what I see is that VB is a destabilizing state of erratic breathing that in turn destabilizes the Auto Controller & thus rather than trying to treat it the machine tries to avoid it.

DSM

Doug,

Thanks for that link and the post on the other thread. I've been really busy lately and haven't been able to keep up with many of the threads on the forum.
Lots of it is still over my head, but what I do understand helps.

Now, if we only knew what percentage of VB was "good" or "bad"......or maybe it's relative to each person.

Den

dsm wrote:This link is far more useful re VB and what it means - it is written by the people who developed the Respironics Auto that it is scored on

viewtopic.php?f=1&t=36412&st=0&sk=t&sd= ... 90#p316599

DSM

#2

If anyone reads right through the patent info it tells us a number of things - these are my interpretations & am happy to debate hem ...
1) VB is not an event as such but is identified as erratic breathing.
2) The patent writers imply that when it is detected they seek to revert back to the situation before it was detected
3) The machine reverses pressure at a max rate of 0.5 CMs per min until the VB goes away or 2.0 CMs is reached


So, If VB doesn't go away the machine goes back to the pressure that it was at before it was detected & stays there for 15 mins

So what I see is that VB is a destabilizing state of erratic breathing that in turn destabilizes the Auto Controller & thus rather than trying to treat it the machine tries to avoid it.

Thanks, Doug!

The patent descriptions unfortunately don't list the physiologic reasons that VB occurs. Nor do they say whether the SQL VB statistic itself reflects: 1) time spent in the VB control layer part of the algorithm ( certainly not in the CPAP case as Den points out---although a stubbed routine could very easily accommodate a "would have spent time" VB statistic), or 2) total time the patient spent in a Variable Breathing condition.

Right about now I'm favoring the theory that the VB statistic (not the algorithm control layer) tracks the patient, and that it was intended for in-house epidemiology regarding just how much or little breathing instability occurs across the population---despite PAP machine use.

Doug,

that makes perfect sense that it goes back to where it encountered the VB, the same guys must have designed the NRAH circuit, cause
the NRAH circuit does something similar it says billy-bob where did we go wrong? Well cousin Ed, my guess is about 6 events and 3 pressure increases ago. What do we do now? Drop pressure and let's have a beer for 15 minutes, we'll leave our bottles here so they know where it was.

Snoredog wrote:Doug,

that makes perfect sense that it goes back to where it encountered the VB, the same guys must have designed the NRAH circuit, cause
the NRAH circuit does something similar it says billy-bob where did we go wrong? Well cousin Ed, my guess is about 6 events and 3 pressure increases ago. What do we do now? Drop pressure and let's have a beer for 15 minutes, we'll leave our bottles here so they know where it was.

Now THAT description makes sense!.......(to me, anyway).


Den

Wulfman wrote:

Snoredog wrote:Doug,

that makes perfect sense that it goes back to where it encountered the VB, the same guys must have designed the NRAH circuit, cause
the NRAH circuit does something similar it says billy-bob where did we go wrong? Well cousin Ed, my guess is about 6 events and 3 pressure increases ago. What do we do now? Drop pressure and let's have a beer for 15 minutes, we'll leave our bottles here so they know where it was.

Now THAT description makes sense!.......(to me, anyway).


Den

Gotta hand it to the 'dog - he always gets right to the heart of the issue

DSM

Throw almost any idea ball in the air & he will get it chew it & drop it right at your feet even if it is a tad tattered.

ozij wrote:

-SWS wrote:I've sure vacillated back and forth regarding this clue as well. My take is that the entire SQL data set was designed for APAP.

I don't think that's quite the reason, sinced the fixed pressure machines do not report flow limitations, which the APAPs do....
Curiouser and curiouser.

Why use VB in a fixed pressure machine, and ignore flow limitations?
What about a CFLEX level VB correlation?

I didn't realize that FL was also omitted from the SQL tables sitting in the CPAP's card. In that case, I think you have an excellent point about VB not simply being an APAP design remnant.

And as Den points out, the VB control layer isn't running on the CPAP machine. I just don't think a stubbed VB timer is reporting "VB would have run" time in the CPAP case.

So I guess I am starting to strongly favor that theory about the VB statistic (not VB control layer) being used for in-house epidemiology of some kind---perhaps CSDB tendencies----such as James' case of higher than usual VB numbers. Obviously the VB statistic would have some in-house specificity/sensitivity estimate for whatever Respironics was hypothetically trying to assess on an epidemiological basis. Curiouser and curiouser as well.

SWS,

I am sure you know exactly what can cause VB - some examples

> neurological conditions that trigger constant anxiety or excitability
> some kinds of medication (often taken for the above)
> other medical conditions that interrupt sleep

etc: etc:

If we accept that VB when defined as 'erratic' breathing - is detected - and the machine has already tried all the known event evaluations. Then we are left with
an (as yet) untreatable instability in the patients breathing. Walk away.

Whereas PB (Periodic Breathing) is treatable & there are brands of machine designed to do just that.

So why would an AUTO maker want to measure it - to know when to walk away. Even if to have a beer or two

DSM

Den cites an excellent point IMO, Doug: Why would a CPAP machine even measure VB, then? True VB is not reported on the Encore reports for CPAP or APAP.

But there is no algorithmic "walking away" as the CPAP machines runs its straight pressure---while collecting that data about the time a patient spent in a variable breathing condition.

-SWS wrote:Den cites an excellent point, Doug: why would a CPAP machine measure VB? It's not reported on the Encore reports for CPAP or APAP for that matter.

But there is no algorithmic "walking away" as the CPAP machines runs its straight pressure---while collecting that data about the time a patient spent in a variable breathing condition.

SWS

Very interesting point - so now we need to find the patent for that cpap and see what the designers say.

So which cpap is it (my guess the Respironics models) - so off I go on my next candy finding hunt - hopefully the designers will (as they did with the AUTO) state what VB is in their eyes and why it matters.

Interestingly, to gather VB involves algorithms normally found on AUTO machines. But, if Respironics are now doing what Resmed did with the S7 - both the cpap & auto were the same machine but one (the cpap) had a metaphorical rubberband jammed into the works to stop it AUTOing, & we plebs had to pay a fee to have it removed & run like an AUTO

DSM

#2
the above metaphorical rubberband is part joke but part real. I once used to apply 'Engineering Changes' to multi-million dollar computers from the largest mainframe supplier in the market, that involved me removing a wire or two so a disabled feature could run & the customer get charged a higher rental charge