Using a Bipap Auto SV and using a Vpap Adapt SV

dsm wrote:But, SWS - the 2001 SV machine technology was primitive and very complicated as in the Autoset CS.

But, dsm, that 2001 SV machine targeted flow. And targeting flow is what you said will always alleviate obstruction. And that 2001 SV machine used a third level fluctuating PS, since that is, the essence of SV.

dsm wrote:So today we have a machine (currently very expensive) that adds a third level of breathing aid (PS) & as clear as the nose on my face, can raise PS to respond to me slowing my breathing to a point where Ipap is not effective enough.

Did I mention yet that the 2001 SV machine did that as well? Because that is, after all, the essence of Servo Ventilation. And wasn't the 2001 machine Servo Ventilation?

So far the 2001 Servo Ventilation machine did everything you claim addresses obstruction: 1) targets flow, and 2) automatically adjusts PS.

Yet neither Respironics nor Resmed claim that Servo Ventilation automatically addresses obstruction. Only you two guys who have taken it upon yourselves to rescind that which both manufactures very clearly claim to this day....

Bravo for being gutsy enough to take Servo Ventilation in a whole new direction the rest of medicine has failed to go...

.

-SWS wrote:

Banned wrote:

-SWS wrote:Banned, I'll admit that I've been wondering about your pull-the-mask-off events with the Vantage. Might those have been machine-induced periodic breathing?

I don't think so. I was waking up with these fits prior to CPAP and going to the ER in the morning for chest pain. The Respironics CPAP Pro took care of things for awhile, than the Vantage took care of it for awhile 'til it came back with vengeance. Including the chest pain. I never bothered with Bi-levels, other than going straight to the Adapt SV. No more fits, chest pain, or ER visits since on the Adapt SV.

Banned

Okay, so let's forget about a machine-induced disorder or complication for the moment...

We can still presumably fit those pre-CPAP episodes as (respiratory-controller related) periodic breathing---with associated apneas and/or hypopneas. Then sub-optimally controlled with CPAP followed by APAP. Finally optimally controlled with VPAP Adapt SV.

How well/poorly does that theory seem to fit from your perspective, Banned? Somehow standard OSA just doesn't seem to fit the experiences you or DSM have described---including and especially that part about only finding suitable treatment with Servo Ventilation.

I'm good with your respiratory-controller-related-periodic-breathing and associated apneas and/or hypopneas. I've never been particularly tired during the day. I was diagnosed with only mild SA. My best guess is (as you stated so eloquently) that the SV is capable of providing unintended ventilatory support and benefit for a myriad of breathing anomolies, both known or unknown. A friend who I had introduced to CPAP a couple of years ago, and who bought his Vantage on my script, emailed me one day in the spring of '07, "You should take look at this Adapt SV". I got an Adapt SV shortly after he did. I credit him everyday for saving my life.

Banned

Banned wrote:My best guess is (as you stated so eloquently) that the SV is capable of providing unintended ventilatory support and benefit for a myriad of breathing anomolies, both known or unknown.

Your guess could be spot-on, Banned. There's no question in my mind that if you target flow, you're going to alleviate some obstruction (assuming that you are under-titrated for those obstructions in the first place).

But your whole saga does not at all describe the typical OSA experience. I still have you down for episodic but not nightly periodic breathing. And you probably did not have a PB episode the night of your PSG.

I am glad you found the VPAP Adapt SV. And I can't blame you one bit for assuming it's a virtual panacea in light of what it did for you.

SWS Banned, Thanks for the spirited debate

There are so many interesting sidelines to effective cpap therapy.

I certainly didn't state & never have that SV will 'always' automatically treat obstruction. (SWS's mischevious quote "Then we have Banned and dsm telling everybody that SV machines are going to "always" automatically treat obstruction. "). SWS shame on you .Didn't you read the bits where I said the Adapt SV did not help me ? - did you read the posts where I cautioned everyone to be careful they don't go spending big money to buy a type of machine that doesn't solve their issues & may not have been designed to.

I have said & will continue to do so, that aspects of these SV machines are highly likely to find their way into future cpap machines targeting OSA.

The tri-level concept of using PS on top of Ipap is a very powerful one for a myriad of OSA reasons but I'll save that debate for another day.


Cheers DSM

dsm wrote:I certainly didn't state & never have that SV will 'always' automatically treat obstruction. (SWS's mischevious quote "Then we have Banned and dsm telling everybody that SV machines are going to "always" automatically treat obstruction. "). SWS shame on you .Didn't you read the bits where I said the Adapt SV did not help me ?

Well, ummm...back just one page, on page 9....

dsm wrote:I know the PS was not specifically designed to treat OSA but by the way it works it was always going to do it.

I agree though that the manufacturers aren't selling this aspect & neither have they offered any testing in that regard.

---

DSM

(Emphasis in red added.)

Surely every manufacturer wants to squeeze every drop of "good stuff" into their marketing claims and recommendations for their machines, so...when -SWS mentions: "neither Respironics nor Resmed claim that Servo Ventilation automatically addresses obstruction"... well... there might just be a reason why they don't make such a claim.

-SWS definitely has very patiently explained why that claim is not made. Perhaps it would be helpful to go back and read, re-read, and re-re-read what he's been explaining about what PS in an SV machine is designed to do. And not do.

dsm wrote:aspects of these SV machines are highly likely to find their way into future cpap machines targeting OSA.

I agree.

Rested Gal,

I believe that is taken out of context. What I say there did not mention all OSA. What it had to do with was what Respironics say the SV actually does in flight. To explain ...

The SV will always raise pressure if the sleeper's inspiration falls below the target for that breath - remember this test is carried out for every breath - halfway through each breathe-in cycle the software makes a decision as to if the breather's inspiration is going to hit the target peak flow. If not it raises pressure within that breath. (see Slide #3 below). The machine doesn't reject one hypopnea over another i.e. it does not say aha! this hypopnea is an obstructive hypopnea therefore I will ignore it!.

In one of the slides below in point 1 they are meaning that the Bipap SV treats OSA generally with clinician adjusted Epap (they use the word Bipap but mean Epap+Ipap), then they say the SV will normalize complicated breathing patterns by "ventilating the patient appropriately during periods of apnea and hypopnea". With a hypopnea, the machine does not differentiate between a central hypopnea or an obstructive hypopnea, it will always deal with them both the same way and as already said above it will not ignore an obstructive hypopnea. The machine responds to breaths that fail to meet peak flow. Irregular breathing presents itself to the machines as a hypopnea or flow-limitation and a variation in breathing rate. The machines uses its target peak flow detection to normalize irregular breathing.

Another slide below says that the machine treats centrals with a timed back-up rate. Just like an S/T Bilevel does. That is well understood and has been around since Bilevels with timed mode came out.

The last slide shows the breath by breath decision making cycle.

So what I see them saying is that the SV will always respond to a hypopnea event if that breath is not going to meet the target peak flow.
Looking at how the machine works and having used it for 2 months, I am satisfied it does exactly what it says and what I am saying.


I hope this clarifies the point & explains my wondering how that transmorphed into responding to all cases of OSA ?

DSM



SLIDE #0



SLIDE #1




SLIDE #2




SLIDE #3




Cheers

DSM

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CPAPopedia Keywords Contained In This Post (Click For Definition): respironics, bipap, Hypopnea

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): respironics, bipap, Hypopnea

dsm wrote:With a hypopnea, the machine does not differentiate between a central hypopnea or an obstructive hypopnea, it will always deal with them both the same way and as already said above it will not ignore an obstructive hypopnea.

Right, Respironics is clearly asking the clinician to manually titrate the obstructive hypopneas away because the machine cannot differentiate.

There's that little snag of mathematical modeling that goes into the front end of a design. And Respironics clearly wants to use upward-fluctuating PS to rapidly ventilate an open airway (mathematically modeled for a low airway impedance. The chart you have posted above shows a targeted impeller response for a low impedance open airway that needs to be ventilated (not quickly thrust/splint open under high airway impendence circumstances).

So why do we think Dave is burning out BiPAP AutoSV machines at a fast and furious rate, DSM? I'll give you a hint. It doesn't have the least do with stomach acid creeping up and rotting the BiPAP AutoSV! It has to do with the fact that the BiPAP AutoSV is designed to very quickly ventilate a low-impedance open airway. Dave keeps burning the motors out because his VCD-related airway closures repeatedly present the motor a high-impedance airway closure that needs to be quickly ventilated.

You keep repeating that SV flow targeting will be identical for obstructions and open-airway central events, but there are an entire slew of considerations that make the manufacturers ask to this day that obstructive events be manually titrated away FIRST. But you seem to know much better than both manufacturers.

dsm wrote:Your comments seem to imply that the SV should not be providing me with effective OSA therapy...

Let's see... you couldn't get effective treatment with CPAP or APAP. You received slightly better treatment with fixed BiLevel. And recently you discovered that you can only get effective treatment with the Respironics BiPAP autoSV.

Despite you comment above, you don't sound like a standard OSA patient to me, Doug. My comments really imply that I think one of those machines is probably alleviating your likely periodic breathing (hint: it's the Respironics SV).

dsm wrote:I have said & will continue to do so, that aspects of these SV machines are highly likely to find their way into future cpap machines targeting OSA.

I agree there. But mathematical modeling and a much earlier response for higher-impedance obstructions will have to fold into the equations. You can't responsively thrust the hell out of airway obstructions during a single inspiratory cycle and expect patients to: 1) sleep through that, 2) avoid stretch receptor homeostatic disturbances (which don't happen when open airways are simply being ventilated rather than quickly stretched), and 3) cause premature motor wear.


But most importantly please don't rescind manufacturer recommendations that have stood since 2001 (when flow targeting and so-called "trilevel" PS were first released). Both manufacturers stand pat on the same manual-titration-of-obstructions to this day. That should tell you something.

dsm wrote:SWS Banned, Thanks for the spirited debate

Hey, we're good mate. You're one of my best friends on this forum. And Banned is a mountain of a man in my eyes.

rested gal wrote:

dsm wrote:aspects of these SV machines are highly likely to find their way into future cpap machines targeting OSA.

I agree.

Speaking of good friends it's great to see you in any thread, Rested Gal!

It's bad enough that we're all jealous that SAG's new granddaughter has been denying us SAG's time. But now we also have to contend with Rested Gal's client load during her busy season!

The double audacity of it all!

.

SWS Quote "You keep repeating that SV flow targeting will be identical for obstructions and open-airway central events, but there are an entire slew of considerations that make the manufacturers ask to this day that obstructive events be manually titrated away FIRST. But you seem to know much better than both manufacturers."

SWS

You are compressing the meaning of OSA here. You are saying that the clinician is the only entity that can treat OSA (with Epap & Ipap on an SV machine). NO cpap machine stops all OSA events - if they did we would never see an AHI above 0 !.

Implying that only Epap & Ipap resolve all OSA events flies in the face of normalcy. In good circumstances the airway is usually held open by Epap (because it was set properly ). Ipap is set to reduce (repeat reduce) hypopneas & flow-limitations. With as little as I know about OSA I can assure you other OSA events will and do occur that get past those base Epap & Ipap settings the same applies to any bilevel or cpap machine.

So I don't believe any one here disagrees that the base OSA (worst case events) are dealt with by Epap & Ipap but there are events above those settings. They are what typically show up in most people's nightly data in their AHI score. If for example Autos or Cpaps dealt with all OSA events with the titration CMS they are allocated, then no one would ever have AHIs greater than 0 but we all know that few people attain a 0 score.

Much of this forum is devoted to people discussing how they can reduce OSA events by way of their AHI scores !.

So in the case of the SV it is going to see those above baseline OSA events (Epap & Ipap) and it will deal with them. That is precisely what I said. The SV will always deal with a hypopnea the same be it obstructive or central. Not all hypopneas result in blocks - you made that very point yourself yesterday.

Re Daves motor 'burnouts' - do you know for a fact that he keeps burning out motors ?. The way the machine is designed. The motor runs at a continuous speed and under a steady load and the airvalve controls where the air goes. There isn't the direct load on the SV motor that there is on a machine with a combined motor/blower unit. So that point puzzles me .

Cheers

DSM

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CPAPopedia Keywords Contained In This Post (Click For Definition): cpap machine, Titration, AHI, Hypopnea

SWS wrote:

dsm wrote:With a hypopnea, the machine does not differentiate between a central hypopnea or an obstructive hypopnea, it will always deal with them both the same way and as already said above it will not ignore an obstructive hypopnea.

Right, Respironics is clearly asking the clinician to manually titrate the obstructive hypopneas away because the machine cannot differentiate.

There's that little snag of mathematical modeling that goes into the front end of a design. And Respironics clearly wants to use upward-fluctuating PS to rapidly ventilate an open airway (mathematically modeled for a low airway impedance. The chart you have posted above shows a targeted impeller response for a low impedance open airway that needs to be ventilated (not quickly thrust/splint open under high airway impendence circumstances).


### AGREE but haven't we agreed that Epap & Ipap took care of high-impedance airway issues ???. Isn't a normal hypopnea around the 50% flow mark - say half-impedance ?


So why do we think Dave is burning out BiPAP AutoSV machines at a fast and furious rate, DSM? I'll give you a hint. It doesn't have the least do with stomach acid creeping up and rotting the BiPAP AutoSV! It has to do with the fact that the BiPAP AutoSV is designed to very quickly ventilate a low-impedance open airway. Dave keeps burning the motors out because his VCD-related airway closures repeatedly present the motor a high-impedance airway closure that needs to be quickly ventilated.


### Covered in another post


You keep repeating that SV flow targeting will be identical for obstructions and open-airway central events, but there are an entire slew of considerations that make the manufacturers ask to this day that obstructive events be manually titrated away FIRST. But you seem to know much better than both manufacturers.


Hang on , you keep twisting the meaning of what I said. I said hypopneas now you say I said obstruction (along with the broad range of meanings it implies). Then you go and argue against this meaning that I didn't use ! (naughty naughty). Please stick to the wording I used.

But of course, I do Agree that the baseline OSA gets titrated with epap and ipap. All titration sessions attempt to set a baseline for any cpap machine then we cpappers grapple with the OSA events that occur above that line. I am saying that the SV offers a mechanism to do what we didn't have before. It is exactly the mechanism in the SV used to normalize irregular breathing. It delivers added PS and it works. (Please don't now say I said it fixes zero flow apneas - we both agree that epap & ipap were set to do that )

dsm wrote:Your comments seem to imply that the SV should not be providing me with effective OSA therapy...

Let's see... you couldn't get effective treatment with CPAP or APAP. You received slightly better treatment with fixed BiLevel. And recently you discovered that you can only get effective treatment with the Respironics BiPAP autoSV.

Despite you comment above, you don't sound like a standard OSA patient to me, Doug. My comments really imply that I think one of those machines is probably alleviating your likely periodic breathing (hint: it's the Respironics SV).


Whatever you think my condition sounds like, it is the PSG studies that I and my RT must look to. They clearly show no centrals & vanilla OSA. I am sorry SWS but the PSG study has to trump remote divining of my SA

Also it is presumptuous to say that because I get excellent results from an SV machine I must therefore have the SA conditions the vendor labels it for

Perhaps this new machine is just very very good at cleaning up those annoying positional apneas

dsm wrote:I have said & will continue to do so, that aspects of these SV machines are highly likely to find their way into future cpap machines targeting OSA.

I agree there. But mathematical modeling and a much earlier response for higher-impedance obstructions will have to fold into the equations. You can't responsively thrust the hell out of airway obstructions during a single inspiratory cycle and expect patients to: 1) sleep through that, 2) avoid stretch receptor homeostatic disturbances (which don't happen when open airways are simply being ventilated rather than quickly stretched), and 3) cause premature motor wear.


But most importantly please don't rescind manufacturer recommendations that have stood since 2001 (when flow targeting and so-called "trilevel" PS were first released). Both manufacturers stand pat on the same manual-titration-of-obstructions to this day. That should tell you something.


Am still not clear on what got rescinded. We both know (I assume) that the original Sullivan Autoset CS was a 13 lb monster that was highly specialized very experimental and targeted to Cheynes-Stokes Respiration. They only broadened its capabilities in 2006. Also, I shouldn't need to remind you of all people that the Bilevel was initially only for COPD patients yet today is one of the better selling advanced cpap machines and now at an affordable price.

Again, I am not disputing that the SV machines are currently positioned for use in a range (not just CSR) of situations. I am merely pointing out that the tri-level capability can just as effectively tidy up above the baseline OSA events as it does irregular breathing.

dsm wrote:SWS Banned, Thanks for the spirited debate

Hey, we're good mate. You're one of my best friends on this forum. And Banned is a mountain of a man in my eyes.


SWS, you are one of the people that makes this forum so especially interesting

dsm wrote:You are compressing the meaning of OSA here. You are saying that the clinician is the only entity that can treat OSA (with Epap & Ipap on an SV machine). NO cpap machine stops all OSA events - if they did we would never see an AHI above 0 !.

I thought OSA was a disease of airway compression! Seriously, I agree there will be residual obstructive events after an OSA titration. But the purpose of any OSA titration is to get rid of the vast majority of those obstructive events.

And Respironics wants to make sure that obstructive objective is met so that their Servo Ventilation algorithm can very quickly ventilate open airways rather than inflate obstructions.

By the way, look up Respironics patent 5535738. Respironics has wanted to quickly address obstruction with what you call "tri-level" PS (proportional assist ventilation or PAV) since before 1994! They still don't have a proportional assist ventilation machine to market they can claim effectively does PS-based PAV for obstructions!!!

Homeostatic disturbances and comfort issues related to very quick airway stretch are real issues in pathophysiology. Responsively ventilating an open airway with targeted flow is very different than quickly blasting an obstruction open. That's why all automatic OSA-targeted machines (including automatic BiLevels) still perform that latter task of airway inflation very slowly to this day. And that's why the new designs that come out still inflate/dilate obstructions very slowly: disturbance-related pathophysiology hasn't changes one iota over all those years.

That's also why Respironics and Resmed want as many obstructions addressed with fixed CPAP or fixed BiLevel pressures (EPAP and IPAP min) as possible. That's also why the above 1994 patent application has yet to come to market for simple cases of pure OSA.

dsm wrote:Implying that only Epap & Ipap resolve all OSA events flies in the face of normalcy.

The purpose of EPAP and IPAP for any OSA patient on any BiLevel machine is to eliminate as many obstructions as possible. Clinical acceptability is getting it under 5 with nothing more than fixed pressure. And normalcy is getting it down below 3, last I checked. That's the purpose of any OSA titration: to eliminate as many obstructive events as possible.

Respironics really wants their Servo Ventilation machine to perform Servo Ventilation---rather than abruptly "Servo Airway Stenting" large numbers of under-addressed airway obstructions.

dsm wrote:Re Daves motor 'burnouts' - do you know for a fact that he keeps burning out motors ?.

I know Dave didn't have this problem with previous xPAP machines (so tentatively rule out the corrosive theory). I also know none of Dave's previous xPAP machines tried to rapidly increase pressure from IPAP min to 30 cm in the course of under two seconds---let alone in response to a very high-impedance VCD airway closure.

Going from EPAP to 30 cm in under one second during a low-impedance central event would place a fair amount of strain on that impeller. But attempt to repeatedly do that in response to a high-impedance airway closure and you're going to go through those SV motors at the unacceptable rate that he is.

dsm wrote:The way the machine is designed. The motor runs at a continuous speed and under a steady load and the airvalve controls where the air goes. There isn't the direct load on the SV motor that there is on a machine with a combined motor/blower unit. So that point puzzles me

Doug, I'm fairly certain the motor receives macro-servo control while the valve is micro-controlled for a very fine-tuned adjustment on the valve output.

dsm wrote:Hang on you keep twisting the meaning of what I said. I said hypopneas now you say I said obstruction.

I'm still confused about which hypopneas you refer to. The machine can't differentiate them as we both agree.

And that's why Respironics wants as many obstructive events eliminated with EPAP and IPAP max as possible. They want the obstructive hypopneas pre-addressed so that Servo Ventilation very quickly ventilates low-impedance central events rather than having to quickly thrust away heavier obstruction.

They also want just as many sporadic obstructive events out of the way ahead of time, to keep from repeatedly downward-skewing recent-average-derived flow targets with clusters of obstructive events. And that includes clusters of target-skewing obstructive hypopneas---which tend to clip otherwise viable flow amplitudes!

dsm wrote:Whatever you think my condition sounds like, it is the PSG studies that I and my RT must look to. They clearly show no centrals & vanilla OSA. I am sorry SWS but the PSG study has to trump remote divining of my SA Smile Smile

Also it is presumptuous to say that because I get excellent results from an SV machine I must therefore have the SA conditions the vendor labels it for Smile

Perhaps this new machine is just very very good at cleaning up those annoying positional apneas

If it is you're lucky. But you slept and felt poorly when your AHI was very good with traditional OSA-targeted xPAP modalities.

Hey, call me presumptuous if you may! I'll even trade presumptions with you. You presume that Respironics and Resmed have been withholding Servo Ventilation as a superior OSA treatment method for the last fifteen years or so. And I'll presume that you feel better with Servo Ventilation because you need occasional respiratory-controller compensation in addition to OSA treatment. And as an added bonus I'll even throw that same presumption in the deal about Banned: he needs some occasional respiratory-controller compensation as well. Deal?


P.S. Doug, thank you for the good discussion! I honestly appreciate it!

-SWS wrote:

dsm wrote:You are compressing the meaning of OSA here. You are saying that the clinician is the only entity that can treat OSA (with Epap & Ipap on an SV machine). NO cpap machine stops all OSA events - if they did we would never see an AHI above 0 !.

I thought OSA was a disease of airway compression! Seriously, I agree there will be residual obstructive events after an OSA titration. But the purpose of any OSA titration is to get rid of the vast majority of those obstructive events.

And Respironics wants to make sure that obstructive objective is met so that their Servo Ventilation algorithm can very quickly ventilate open airways rather than inflate obstructions.

By the way, look up Respironics patent 5535738. Respironics has wanted to quickly address obstruction with what you call "tri-level" PS (proportional assist ventilation or PAV) since before 1994! They still don't have a proportional assist ventilation machine to market they can claim effectively does PS-based PAV for obstructions!!!

Homeostatic disturbances and comfort issues related to very quick airway stretch are real issues in pathophysiology. Responsively ventilating an open airway with targeted flow is very different than quickly blasting an obstruction open. That's why all automatic OSA-targeted machines (including automatic BiLevels) still perform that latter task of airway inflation very slowly to this day. And that's why the new designs that come out still inflate/dilate obstructions very slowly: disturbance-related pathophysiology hasn't changes one iota over all those years.

That's also why Respironics and Resmed want as many obstructions addressed with fixed CPAP or fixed BiLevel pressures (EPAP and IPAP min) as possible. That's also why the above 1994 patent application has yet to come to market for simple cases of pure OSA.

dsm wrote:Implying that only Epap & Ipap resolve all OSA events flies in the face of normalcy.

The purpose of EPAP and IPAP for any OSA patient on any BiLevel machine is to eliminate as many obstructions as possible. Clinical acceptability is getting it under 5 with nothing more than fixed pressure. And normalcy is getting it down below 3, last I checked. That's the purpose of any OSA titration: to eliminate as many obstructive events as possible.

Respironics really wants their Servo Ventilation machine to perform Servo Ventilation---rather than abruptly "Servo Airway Stenting" large numbers of under-addressed airway obstructions.

dsm wrote:Re Daves motor 'burnouts' - do you know for a fact that he keeps burning out motors ?.

I know Dave didn't have this problem with previous xPAP machines (so tentatively rule out the corrosive theory). I also know none of Dave's previous xPAP machines tried to rapidly increase pressure from EPAP to 30 cm in the course of under one second---let alone in response to a very high-impedance VCD airway closure.

Going from EPAP to 30 cm in under one second during a low-impedance central event would place a fair amount of strain on that impeller. But attempt to repeatedly do that in response to a high-impedance airway closure and you're going to go through those SV motors at the unacceptable rate that he is.

dsm wrote:The way the machine is designed. The motor runs at a continuous speed and under a steady load and the airvalve controls where the air goes. There isn't the direct load on the SV motor that there is on a machine with a combined motor/blower unit. So that point puzzles me

Doug, I'm fairly certain the motor receives macro-servo control while the valve is micro-controlled for a very fine-tuned adjustment on the valve output.

dsm wrote:Hang on you keep twisting the meaning of what I said. I said hypopneas now you say I said obstruction.

I'm still confused about which hypopneas you refer to. The machine can't differentiate them as we both agree.

And that's why Respironics wants as many obstructive events eliminated with EPAP and IPAP max as possible. They want the obstructive hypopneas pre-addressed so that Servo Ventilation very quickly ventilates low-impedance central events rather than having to quickly thrust away heavier obstruction.

They also want just as many sporadic obstructive events out of the way ahead of time, to keep from repeatedly downward-skewing recent-average-derived flow targets with clusters of obstructive events. And that includes clusters of target-skewing obstructive hypopneas---which tend to clip otherwise viable flow amplitudes!

dsm wrote:Whatever you think my condition sounds like, it is the PSG studies that I and my RT must look to. They clearly show no centrals & vanilla OSA. I am sorry SWS but the PSG study has to trump remote divining of my SA Smile Smile

Also it is presumptuous to say that because I get excellent results from an SV machine I must therefore have the SA conditions the vendor labels it for Smile

Perhaps this new machine is just very very good at cleaning up those annoying positional apneas

If it is you're lucky. But you slept and felt poorly when your AHI was very good with traditional OSA-targeted xPAP modalities.

Hey, call me presumptuous if you may! I'll even trade presumptions with you. You presume that Respironics and Resmed have been withholding Servo Ventilation as a superior OSA treatment method for the last fifteen years or so. And I'll presume that you feel better with Servo Ventilation because you need occasional respiratory-controller compensation in addition to OSA treatment. And as an added bonus I'll even throw that same presumption in the deal about Banned: he needs some occasional respiratory-controller compensation as well. Deal?
.

Doug, I agree with everything in your post above. I think part of this "peculiarity" has to do with the fact that I want to make very sure that new comers don't get the impression that:

1) adaptive SV is optimized for treatment of pure OSA (it is not according to both manufacturers), or

2) that adaptive SV will yield superior OSA treatment compared to current platforms that are targeted for OSA (I think in most cases SV will not---or the two SV manufacturers would very gladly sell it as such, thereby increasing their OSA market share---the lion's share of SDB treatment, by the way)

Regarding why the Resmed machine didn't seem as smooth to you. Whether that can be attributed to your nasal congestion or leaks, I will soon post the part of the VPAP Adapt SV algorithm that I think is getting thrown off.



In the mean time I have what I hope is an entertaining rhetorical/hypothetical question that might give us some insight into how well or poorly we think an adaptive SV machine might treat purely obstructive OSA. Hypothetical experiment for anyone who's interested:

[hypothetical experiment on]
Take a purely obstructive patient with say an AI of 20 and an HI of 20 (an arbitrary choice). Let's place that hypothetical obstructive AHI=40 patient on adaptive SV. However, let's intentionally set EPAP and IPAP min just low enough to miss roughly half of those apneic and hypopneic obstructions---not to mention plenty of flow limitations. But let's hypothetically set IPAP max as high as possible.

Should we expect adaptive SV to efficiently eliminate the outstanding portion of obstructive AHI and FL with IPAP max? Why or why not?

And if so, should this automated OSA treatment method be preferred over present-day OSA treatment methods?
[/hypothetical experiment off]

So Banned, DSM, and other adaptive SV aficionados... What do we think about automatically allowing adaptive SV to automatically shoot down MOST obstructive events in purely obstructive patients? Why doesn't the medical community just do it that way?



Haven't worked through the above hypothetical experiment myself. Just an exploratory question for fun really...

What do we think about automatically allowing adaptive SV to automatically shoot down MOST obstructive events in purely obstructive patients? Why doesn't the medical community just do it that way?

I don't think it has to do with lack of time to either test OSA patients on ASV, or for lack of time to reach FDA approval. Plenty of time and opportunity has already transpired for that.

I don't think it has to do with cost. Present day adaptive SV development cost is largely a done-deal---and it would get quickly defrayed by much higher-volume sales, since OSA is the lion's share of the SDB treatment market...

I don't think it has to do with any beneficial economics of supporting older and less efficient OSA-treatment platforms. If adaptive SV were a better OSA-treatment platform the two SV manufacturers would have incentive to jointly corner the OSA treatment market (the lion's share of the SDB treatment market).

[quote="-SWS"]

<snip>


[hypothetical experiment on]
Take a purely obstructive patient with say an AI of 20 and an HI of 20 (an arbitrary choice). Let's place that hypothetical obstructive AHI=40 patient on adaptive SV. However, let's intentionally set EPAP and IPAP min just low enough to miss roughly half of those apneic and hypopneic obstructions---not to mention plenty of flow limitations. But let's hypothetically set IPAP max as high as possible.

Should we expect adaptive SV to efficiently eliminate the outstanding portion of obstructive AHI and FL with IPAP max? Why or why not?

And if so, should this automated OSA treatment method be preferred over present-day OSA treatment methods?
[/hypothetical experiment off]

So Banned, DSM, and other adaptive SV aficionados... What do we think about automatically allowing adaptive SV to automatically shoot down MOST obstructive events in purely obstructive patients? Why doesn't the medical community just do it that way?



Haven't worked through the above hypothetical experiment myself. Just an exploratory question for fun really...