ResMed Adapt SV vs. Respironics Auto SV

[-SWS]

It does if you want to accurately account for additions/subtractions to the patient tubing, which isn't accounted for by using K1/K2. Actually measuring the difference of P1 - P2 will be able to account for variables within the circuit, such as bacteria filters, humidifiers and restrictive patient interfaces. This in turn will add the necessary precision to the volume calculation which is critical in establishing Target. Learn Circuit will either actually calculate resistance or alert the user that the circuit intended for use will not work properly (if the calculation is done internally and the K1 - K2 formula is being used).

Despite my initial post that was supposed to be funny and long, I'll take a closer look at this one, SAG. I initially missed the flow exponential in that K1 part of the equation (visual reading jitters have always dogged). Miss an exponential like that... and there goes that funny post.

I'll see what we can bat around a bit regarding K1 and K2. At least here's one intended funny (unrelated to our debate) from what I originally had going in that post:

I was thinking the same thing about the manufacture of tennis balls. All obvious physics observations aside, we're about 11 posts away from being able to conclude (or likely reach an impasse) regarding why they always make them so round and bouncy.

I think I know where the Bong went.

I swear I only had it in my possession for ten minutes. No sooner than I cleared the smoke after getting it from you did DSM confiscate it from me. He is rumored to have converted it into a "distal-pressure tennis-ball tube". When he grabbed it from me he uttered something about helping -SWS and SAG with their utterly insane experiments.

Gee. Not quite the same now....

[dsm]

Hmmmm,

SAG says the proximal sensor line is a set of training wheels for the mask & air circuit. SWS (IMHO quite rightly ) says it is there to (also) provide multiple flow curve sampling of the patient's inhale/exhale curve *at the mask* so it can much more accurately adjust its blower in real time based on the highly accurate input taken from what is happening with the patients respiration at the actual point it is occurring.

I know who is wining this debate thus far

SAG you just have to lift your game.

DSM

[Banned]

With regard to the Paw, SAG would be the strawman, or more aptly, the straw dog.

Banned

[dsm]

With regard to the Paw, SAG would be the strawman, or more aptly, the straw dog.

Banned

Banned,

SAG has not lost this debate at all - the only issue I see thus far is that SWS is producing the more compelling case. If SAG can convince myself and SWS that proximal sensing isn't needed to provide the type of real-time blower response for the type of therapy the Vpap SV machine in particular, addresses, then he will have done so because he has the right argument. I just don't believe that has happened yet.

Cheers

DSM

[-SWS]

Well, from my perspective of -SWS-spectator SAG still has a very interesting argument going on regarding how a more accurate circuit impedance value might impact flow targeting. From my perspective of -SWS-debater, my objective would be to bat that idea down.

From my combined perspective, I don't think that I will personally throw the notions out the window that: 1) sinusoidal flow-sensing at the mask is important to the ASV algorithm based on crucial use of multiple discrete reference points, and 2) flow (derivation) sensing at the mask is important to signal differentiate leaks and thereby avoid pressure runaway with this temporally short-targeted fuzzy algorithm.

From my perspective as -SWS-spectator I want to see if that more accurate impedance value yielded by Learn Circuit and a proximal sensor reading is yet a third hand-in-hand reason to get that same (pressure-based) flow sensor line up at the mask. However, this is a debate to explore and have fun along the way. So I will bat hard at that notion of SAG's that Learn Circuit impedance derivation is a compelling reason to get a proximal sensor line at the mask. .

[-SWS]

So I will bat hard at that notion of SAG's that Learn Circuit impedance derivation is a compelling reason to get a proximal sensor line at the mask.

But before I do I'm not sure if there's anything SAG wants to counter about what I humorously called "quibbling". On that note, I won't start my own post that examines fluid-dynamics-based K1 and static-resistance-based K2 just yet (if there are still loose ends about what we have discussed so far).

So below I'll post some of what I had written before I noticed there was an exponential in the K1 part of the equation (hence fluid dynamics). Here's some of what I had written---up to the point, and even slightly beyond, humorously accusing SAG of quibbling. You'll notice almost all of my point-counter-point below is intended as very little more than humorous quibbling, for the sake of entertainment value. There's no real substance in much of my repartee below. Recall that my objective is to explore both the topic-at-hand and SAG's position... as well as have fun along the way.

The issue regarding machine functionality is truly comprised of what the machine detects as well as how it signal-processes and decision-renders during those two treatment scenarios.

I thought the issue was determining the function of the proximal pressure line.

Analytically working with machine detection, processing, and rendering toward purpose-determination of proximal sensing subscribes to deductive reasoning of all wacky things. But syllogistic reasoning has already been flagged as a legitimate caveat---as useful as it can be when done properly.

Of course, remove that proximal sensor line, as you did in your experiment...

What experiment is that?

Right. Quibble as you may (which is fun for me too, by the way), you beautifully showed Flow2 at the machine as a reference-point truncated sinusoid. Flow2 was really Pressure2 in your experiment. But take that Pressure2 and slide a virtually identical copy to the right in the time domain so that you now have Pressure2a and Pressure2b. That's what a pressure-differential based flow sensor essentially does to mathematically derive flow (as a function of sequential pressure and time). And that signal-processing function always yields a resultant zero-slope Flow2, doesn't it? And while zero-slope on a sinusoid peak doesn't always mean a whole lot to temporally-long calculations (tidal volume, etc), it just skews the heck out of instantaneous sinusoidal reference-point math, doesn't it? Especially when temporally short-based technical objectives prevail via fuzzy-based PAV.

Well, we're about 11 posts from concluding anything, if, in fact, we are able to conclude anything at all..

We? Who's we? When exactly may we conclude? Thank you for being our group-think leader---especially when it comes to science lessons.

Our? Who's our?

I thought "our" was (at the very least) indirectly defined by some of "those" who cautiously and understandably acknowledge "we". But I have been known to spontaneously shout pleasantries to the moon, the raving group-think dissenter that I am.

The above patent-description wording...

That's not patent wording, that's Ohm's Law.

The wording "Pprox may participate in Learn Circuit to calculate Resistance" is Ohm's law??? I thought I understood Ohm and his law adequately. But I didn't know that he was a time traveler who participated in ASV Learn Circuit. And regardless of diversionary hair-splitting, isn't the word "may" still in there? And who wrote that magic word anyway? Did I mention tail-chasing and entertaining sophistry in this thread yet?

Anyway, if there are any genuine loose ends (or even humorous repartee) that SAG would like to bat at before moving on to gas-based fluid dynamics and K1 & K2...

[Snooze_Blues]

Not to lose track of Banned's recent question for Snooze_Blues:

Hey Snooze,

I must have missed the outcome of your sleep study. Did the doc scribe an ASV?

Banned

Sorry if we hijacked your thread, Snooze_Blues.

-SWS, No problem.

Banned, Had my 2nd PSG. Did NOT titrate me on ASV. Not sure why yet, but the sleep tech thought she had to remove the proximal line to disconnect my mask until I told her it was a quick disconnect. That didn't inspire much confidence. I hope she didn't break it. I posted mention of my PSG in this thread:

http://tinyurl.com/2d5h28

I don't have the 2nd PSG summary yet and haven't talked to the sleep nurse. Maybe tomorrow. I'm putting if off hoping I won't blow up about all the lab noise, my lack of sleep, an apparently inexperienced sleep tech, and what I believe is their tack of just guessing at my pressure based on insufficient data and then giving up if I say anything that resembles, "I feel better", at my next "follow-up" visit in a month.

On the one hand, I'm encouraged that they are keeping me on CPAP. The equipment is cheaper and it must surely mean all the central apneas observed in the 1st PSG have resolved themselves since then, at least one would hope since they didn't bother switching the ResMed ASV machine off CPAP and into ASV mode (assuming they knew how).

On the other hand, if I do "feel" better, maybe I shouldn't be concerned with any of this. I'm too tired, anxious, and depressed to think about it right now, but I appreciate the inquiry.

[StillAnotherGuest]

Drag this along with you. It defines the reimbursement criteria for ASV, and might be a little more helpful than "some nut on the internet said":

http://reimbursement.respironics.com/do ... autoSV.pdf

So if you have central sleep apnea, defined as:

1. An apnea hypopnea index (AHI) greater than 5; AND
2. Central apneas/hypopneas greater than 50% of the total apneas/hypopneas; AND
3. Central apneas or hypopneas greater than or equal to 5 times per hour; AND
4. Symptoms of either excessive sleepiness or disrupted sleep.

and CPAP failed, then you coulda/shoulda been trialed on ASV.

If you trialed ASV and got better, then ASV is reimburseable.

While you're there, grab all the graphics from both studies. Then we can discuss "periodicity" vs "post-arousal centrals".

Anyway, if there are any genuine loose ends (or even humorous repartee) that SAG would like to bat at before moving on to gas-based fluid dynamics and K1 & K2...

Right. I'm getting my tail-chasing, arcane explanations, pictures, and graphs together as we speak.

SAG

[-SWS]

Drag this along with you. It defines the reimbursement criteria for ASV, and might be a little more helpful than "some nut on the internet said":

http://reimbursement.respironics.com/do ... autoSV.pdf

So if you have central sleep apnea, defined as:

1. An apnea hypopnea index (AHI) greater than 5; AND
2. Central apneas/hypopneas greater than 50% of the total apneas/hypopneas; AND
3. Central apneas or hypopneas greater than or equal to 5 times per hour; AND
4. Symptoms of either excessive sleepiness or disrupted sleep.

and CPAP failed, then you coulda/shoulda been trialed on ASV.

If you trialed ASV and got better, then ASV is reimburseable.

SAG, I hope you didn't take offense at my willingness to debate the proximal-sensor-line issue or playfully engage in humorous barbs. I have seen you partake in both of those often enough (debates and humorous barbs), that I was trying to indulge what I thought were your own preferences. If you took offense my apologies. If you didn't great!!! But to be on the safe side I think I'll drop the humorous repartee. I'm probably completely failing at that part. But so far I think I am doing an O.K. job of exploring the proximal-sensor topic via debate. I think I'll drop the debate approach just to be on the safe side as well.


However, looking at the above document, I don't see how it serves what we were originally debating. It seems like a new and entirely worthy topic. I thought we were debating the likely reasons that Resmed might have placed a proximal sensor line at the mask. You specifically thought that Resmed's design reason was to avoid pressure runaway by attaining more accurate impedance values during Learn Circuit.

What does the above document have to do with our present exploration of why Resmed placed that proximal sensor line at the mask???

Anyway, if there are any genuine loose ends (or even humorous repartee) that SAG would like to bat at before moving on to gas-based fluid dynamics and K1 & K2...

Right. I'm getting my tail-chasing, arcane explanations, pictures, and graphs together as we speak.

I was really putting a call out for loose ends regarding the proximal-sensor topic at hand, versus off-topic issues like modality, efficacy, and reimbursement. Are we working that same exploratory debate about proximal-sensor design considerations, or are we taking a detour to work yet other entirely worthy topics?

If you're sleep efficiency is only 37% Resmed placed a proximal sensor line at the mask (or alternately left flow-sensing way down at the machine) because...

Somehow this doesn't look and feel as if we're staying on course. And -SWS-spectator was just starting to fine-tune his own proximal-sensor opinions based on SAG's own (very much) on-topic input about K1-related fluid dynamics.

[-SWS]

On the other hand, if I do "feel" better...

Well, I am glad to hear about that hypothetical expectation, Snooze. Mindset truly helps in a huge way, in my opinion.

So please keep on plugging away. And as you already know the people here are willing to bounce ideas around or just commiserate, whenever that last one seems to help that is.

[StillAnotherGuest]

However, looking at the above document, I don't see how it serves what we were originally debating. It seems like a new and entirely worthy topic. I thought we were debating the likely reasons that Resmed might have placed a proximal sensor line at the mask. You specifically thought that Resmed's design reason was to avoid pressure runaway by attaining more accurate impedance values during Learn Circuit.

What does the above document have to do with our present exploration of why Resmed placed that proximal sensor line at the mask???

That stuff's for Snooze_Blues to help determine his ASV eligibility.

SAG

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): resmed

[Guest]

SAG, WHEW! I was worried that may have been a completely frustrated response with my topic approach. More importantly I am elated, as usual, to see that you are once again pulling graphs and information together to help others.

I think I'll still drop the attempt at humorous repartee, because I'm not so sure I'm doing that part very well. On our topic of proximal-sensor-line design considerations, should we move toward K1 and K2? I hoped to get readily-addressed loose ends closed, since the K1 and K2 examination may be a bit information-dense for a "general-readership" message board.

-SWS-spectator is leaning toward thinking Learn Circuit presents a third hand-in-hand reason to get a proximal sensor line up at the mask. I also think dynamic leak signal differentiation likely presents the most skew avoidance (compared to either sinusoidal reference point skew or Learn Circuit impedance skew).

[-SWS]

Since the K1 and K2 topic-examination is truly a bit information-heavy, it might make more sense to hold off on that part for just a while.

I would much prefer seeing anyone here receiving SAG's expert help over any given arcane informational foray that doesn't directly help others on this message board. And quite frankly proximal-sensor-line analysis doesn't come close to helping anyone nearly here as much as the usual stuff that SAG does. That proximal-sensor-line topic is merely interesting to but a very few of us.

But it's not all that helpful compared to what SAG is getting ready to present (the ORIGINAL "original" topic of all audacious things.)

[rested gal]

That proximal-sensor-line topic is merely interesting to but a very few of us.

It's interesting to me, even if I don't understand all (or even much, sometimes!) of the discussion about it.

Just guessing, but I think it's probably interesting to Snooze, too:

Did NOT titrate me on ASV. Not sure why yet, but the sleep tech thought she had to remove the proximal line to disconnect my mask until I told her it was a quick disconnect. That didn't inspire much confidence. I hope she didn't break it.

[-SWS]

I promise to get back into K1 and K2. But if SAG's getting ready to do what he does best... Well, let's just say that I personally think that is positively one of the top-most helpful things that occurs on this message board.

And from my own selfish perspective, I prefer sitting back and watching SAG do his PSG/SDB magic. That's what the original topic was about, and I don't want to further dilute that single-most important purpose of this thread.

I will get back to K1 and K2 subtopic exploration, analysis, and even conjecture after we serve what is truly most important here: helping others.

Thanks for the words of encouragement, Rested Gal! .