ResMed Adapt SV vs. Respironics Auto SV

[doggie]

The folks in the sleep lab appear to be bumbling imbéciles. Which is so often the case these days. Ignorance is almost demanded for success.

[dsm]

The folks in the sleep lab appear to be bumbling imbéciles. Which is so often the case these days. Ignorance is almost demanded for success.

I think that some of them can appear that way - esp when the patient can tell the staff how to set up the machines.

Be aware that SAG runs a sleep clinic and no one but no-one would question his insights and titration capabilities. We may have fun debating the way the machines go about their business but SAG & SAG's clinic are a shining example of what is best about a sleep clinic.

DSM

APPOLOGY
- SAG advises me his is a sleep Centre (or is that 'Center' in the US ) - for that mix-up SAG I most humbly appologise DSM

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

[Banned]

And I agree with SAG that the Paw (sensor circuit) measures 1) Space in the mask (learn circuit), and 2) Flow interruption (including leaks).

Banned

[dsm]

And I agree with SAG that the Paw (sensor circuit) measures 1) Space in the mask (learn circuit), and 2) Flow interruption (including leaks).

Banned

Banned,

I think SWS as well as myself agree with you (& SAG) on that matter. The other discussions were about what else the proximal line does on the Vpap Adapt SV. Our debate was about what else we believe the proximal sensor is required for. From my perspective, I mean required in the sense that the machine could not operate to its peak capabilities without the proximal line being present during minute-to-minute therapy.

DSM

[-SWS]

Definitely agree with you there Banned and DSM.

I also think if there were a thousand labs run by a thousand SAGs, you would probably see very few of those patients (if any at all) turn to this message board for help.

I'm hoping there are plenty of SAGs out there and that these posts represent problems in disproportionate numbers. I am convinced there aren't enough SAGs out there, though. When we see SAG take on a typical PSG mess, we probably don't see the positive ripple affect that gradually accrues behind the scenes.

That type of message board demonstration has to have immeasurable positive impact toward awareness regarding a need to improve standards. Then, of course, non-professionals who post here straighten out much more basic therapy problems on a very regular basis. That sends a powerful message to the world as well. Slowly critical mass is achieved toward positive change, thanks to the likes of SAG and a host of other helpful posters on this message board.

Don't confuse my attempt to indulge SAG in humorous debate as any sort of lack of respect or admiration for the way he helps others. Also note that sometimes I include seemingly tangential information, hoping that there just may be something/anything in that tangential information he may be able to make use of. Small contribution compared to what he routinely does for us. He's truly a hero in my eyes. Period.

[StillAnotherGuest]

Be aware that SAG runs a sleep clinic

It's a center!

I think I'll still drop the attempt at humorous repartee

I thought you were going to be the straight guy, and I was going to do the punch lines.

On our topic of proximal-sensor-line design considerations, should we move toward K1 and K2?

Oh, sure, why not. Keeping in mind that that was MBJ's alternative to Pprox for leak calculation in the patent, and I don't suppose that's necessarily a lock. One could also argue that if that's the direction they're headed that it's a hybrid, why else would they ask for mask selection (K1 is not an absolute k).

Fun things to muse about:

The output parameters of AdaptSV (pressure, tidal volume, minute ventilation, leak, rate, target and/or flow) continue to be reported whether Pprox is functional or not.

They don't appear to be grossly affected by what Pprox does (I have heard a conflicting report about this, however).

Learn Circuit will pass without the Pprox line.

Which really doesn't mean anything, but it did make you stop for a second, didn't you?

If anybody thinks there's imbeciles running around now, give it about 6 months.

And none of what we say here should be considered as license to tie the Pprox line in a knot and then go to sleep. Cause you could also wake up dead in the morning, too.

If you do, lemme know, that would suggest that K1 - K2 is being used.

SAG

[Banned]

Fun things to muse about:

The output parameters of AdaptSV (pressure, tidal volume, minute ventilation, leak, rate, target and/or flow) continue to be reported whether Pprox is functional or not.

They don't appear to be grossly affected by what Pprox does (I have heard a conflicting report about this, however).

Learn Circuit will pass without the Pprox line.

Which really doesn't mean anything, but it did make you stop for a second, didn't you?

If anybody thinks there's imbeciles running around now, give it about 6 months.

And none of what we say here should be considered as license to tie the Pprox line in a knot and then go to sleep. Cause you could also wake up dead in the morning, too.

SAG

Holy %#@&*! SAGs right again, duh! When you disconnect the Pprox line and cover the Pprox connector, learn circuit works just fine. So what if rather than tying the Pprox line in a knot, I plugged the Pprox connector with chewing gum and went to sleep? But, before I do that, has anyone done it at the center?

Banned

[-SWS]

Well, I have an explanation that very neatly accounts for that enigma, SAG and Banned. And that tentative explanation accounts for the purpose of running Learn Circuit as that of deriving K1 and K2! I realize how counter-intuitive that sounds.

I'll explain more when I get a batch of client work squared away. Consider the fact that there is more than one way to get a viable (albeit not always best) static and dynamic pair of circuit impedance values (cat skinning if you may). Also consider the concept of fall-back or fault tolerance as an absolute priority in any designer's mind. More later...

And no I didn't get the Bong back from DSM, despite trying that magic word "may" I. He's using it to bombard the side of a building with tennis balls as I type. Every third or forth tennis ball he turns to me and winks knowingly, as he says: "See what I mean?

[rested gal]

If anybody thinks there's imbeciles running around now, give it about 6 months.

You're talking about the kind of people Medicare's recent approval of portable home testing may bring into the field of sleep medicine, I take it?

http://www.aasmnet.org/Articles.aspx?id=777

http://news.corporate.findlaw.com/prnew ... 81834.html

[Snooze_Blues]

...

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

SAG

Anybody have an off-the-cuff estimate of what type media (e.g. 8.5 x 11, disc, tractor feed paper, etc.) and the weight and volume of my PSG "graphics"?

I can't wait to hear the long pause when I ask for these, and the legal docs I'll have to sign and pay for while being escorted quickly in and out of the sleep center building, and the special note that sleep center staffer "Obie" will put into my "file up in Washington with the 27 eight by ten color glossy pictures with the circles and arrows and the paragraph on the back of each one..."

[Banned]

Deleted - Duplication

[Banned]

And none of what we say here should be considered as license to tie the Pprox line in a knot and then go to sleep.
SAG

Ok, I got home, blocked the Pprox line and tried to go to sleep. Immediately there was "Low Pres! Check Circuit" in the LCD and the annoying alarm. However it did feel like the machine was still operating in VPAP mode during the fuss. It also felt like there was no chance for the machine to respond on a breath-by-breath basis. Excuse me while I try to clean the chewing gum from the Pprox line.

Banned

[dsm]

Getting back to SnoozeBlues original theme.


The Bipap AutoSV in SV mode can essentially can do the following ...

1. Can set a base epap (titrated to remove blocking apneas)
2. Can set a Min Ipap (what the pressure goes up to on inhale)
3. Can set a Max Ipap (what the pressure can go up to if flow is not being maintained)

The Bipap AutoSV does not make use of a mask pressure sensing airline (i.e. Proximal line) like the Vpap Adapt SV does. It does all its estimations back at the machine. The approach of sampling only the flow (and rate) allows them to avoid use of the a mask pressure sensing airline line.

The Bipap AutoSV then uses its sampling of flow as determined at the machine end of the airhose and using internal pressure sensors and flow rate sensors, to drive the IpapMax such as to maintain a particular flow target.

The shape of the waveform is set by a risetime setting similar to the Bipap S/T. The breathing rate can be set to Auto or to a specific number. If set to a specific number the machine will work to keep that rate the same.


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The Vpap Adapt SV in SV mode can do the following

1. Can set a base eep (=epap - titrated to remove blocking apneas)
2. Can set a MinPS starting at 3 CMS above eep (eep + minps = Ipap - what the pressure goes up to on inhale)
3. Set a MaxPS starting at 5 above MinPS (what the pressure can go up to if user drops below 90% of last 3 mins MV & breating rate and the machine uses PS to correct this)

The Vpap Adapt SV uses a sensing air line (the Proximal Sensor tube) that samples pressure in the mask as the user breathes. This sampling is in conjunction with flow & pressure sensors in the machine itself.

The Learning Circuit process appears to be the Vpap Adapt SV building an internal 'mask fixed leak' rate table for the mask being used (vs the other models from Resmed that all have a set of tables based on Resmed masks). Using internal 'mask fixed leak' tables has been done by Resmed & Puritan Bennett for years on some of their models but not all.


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The major difference between the machines is the data each samples.
The Bipap AutoSV samples flow & (if activated) rate.
The Vpap Adapt SV samples 90% of the users Minute Ventilation and Rate.


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The remaining question then is how effective either machine is for a specific target user base.

If we look at users with centrals, the Adapt SV appears to be more precise (due to its ability to sense mask pressure vs delivered pressure based on the proximal line) while the Bipap AutoSV appears to be a lot more like a Bilevel but with added ipap pressure support if the machine determines the user is having a central. How the Bipap SV determines if the user is having a central is the open question. Lack of mask sensing suggests it does a best guess, but if it gets this right most of the time, that may be ok.

My impression is that the Vpap Adapt SV in terms of irregular breathing, is tuned like a high-performance F1 sports car.

The Bipap AutoSV is more like a NASCAR racer.

I think each type can do a good job in its own type of race & race track

DSM

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CPAPopedia Keywords Contained In This Post (Click For Definition): resmed, bipap, Puritan Bennett, auto

[Banned]

Nice synopsys, dsm. I'm going to be titrated on 3-day trial with a BiPAP Auto SV at the end of April, even though I use an VPAP Adapt SV. Would it necessarily make a difference which machine I was titrated on?

Banned

[-SWS]

DSM, the ASV manual calls for Learn Circuit to be run when adding more dead space, such as a humidifier.

What do you think of the notion that Learn Circuit may derive: 1) dead-space oriented (fluid) dynamic impedance (which is mathematically flow-directional and thus positive/negative) along with 2) a typical non-dynamic fixed resistance?

The humidifier dead-space purpose of Learn Circuit along with that formula SAG posted (with K1 and K2) strongly corroborate a need to ascertain dynamic impedance (which includes a reciprocal of mask flow conductance).

Just a thought...