CPAPtalk.com

Does anyone know if there is actually a physical difference between the APAP, Bi-level, and ASV machines? Or is it just a software difference that people pay through the nose for?

I've always suspected that the difference is in the firmware in the machine.
All the things that have to be measured for it to work also have to be measured in an auto BiPap machine as well.

You have to measure flow and pressure.
Humidity control would be exactly the same.
The LCD display module would be universal and interchangeable.

Then you have to be able to change pressure rapidly to accommodate the bi-level stuff but both types need to do that.
One difference might be in the blower fan. It is possible that the ASV fan is able to react faster than the BiPap fan as it switches between max pressure (25 cm H2O) and a much lower pressure (in my case 10 cm H20) and back again within one breath cycle.

All of the above is speculation based on my imperfect understanding of the engineering involved.
It would be easy to tell. Just field strip one of each and take a look.
A quick look at the fan and the circuit board would be enough if they are the same.

Anyone willing to sacrifice their ASV for that experiment? It might turn out that it wouldn't be possible to reassemble the machine afterwards into a working machine.

JDS74 wrote:All the things that have to be measured for it to work also have to be measured in an auto BiPap machine as well.

It seems to me that the same is pretty much true for the Autoset, Elite, and even the Escape Auto (even if the Escape Auto doesn't share data with the user/clinician, it's got to detect it to do its job). And as far as motors go, EPR on the Autoset and Elite would probably require the same responsiveness. I would be surprised if there is a different blower in the machines; that's a lot of extra work and expense designing, testing and gaining approval for separate motors when I doubt there'd be a significant difference in manufacturing cost. Easier just to over-engineer one motor.

Indeed, I would not be at all surprised to learn that there is no physical difference aside from branding between any of the machines in the S9 series -- with the possible exception of the Escape, which would not need all of the sensing capabilities of the other machines.

The Latinist wrote:Does anyone know if there is actually a physical difference between the APAP, Bi-level, and ASV machines? Or is it just a software difference that people pay through the nose for?

It's a bit of both.

I know the PR ASV has a different blower than the plain CPAP/APAP, one that's much more durable and probably more powerful given the rapid changes in pressure it needs to provide. I don't remember whether the bi-level machines have the same blower as the CPAP or the same blower as the ASV. I think they're the same as CPAP and it's only the Bi-Level S/T models that have the same blower as the ASV, since they're also "non-invasive ventilators" (NIV).

The difference between CPAP and APAP is purely software, at least for PR.

And the difference between Bi-Level and (one of the other two) is purely software.

I think (I'm not positive) that the difference between Bi-Level S/T and ASV is just software.

Now as to paying through the nose for it, it's not entirely irrational. This isn't just consumer software -- it's a regulated medical device, and they have to perform different clinical research and studies to get the device approved. Those studies are performed with specific software and therapy. So their development and approval costs are definitely different between the two.

Whether the price difference is totally justified I can't say -- just observing that some difference isn't necessarily due to price gouging.

sawinglogz wrote:

The Latinist wrote:Now as to paying through the nose for it, it's not entirely irrational. This isn't just consumer software -- it's a regulated medical device, and they have to perform different clinical research and studies to get the device approved. Those studies are performed with specific software and therapy. So their development and approval costs are definitely different between the two.

Whether the price difference is totally justified I can't say -- just observing that some difference isn't necessarily due to price gouging.

I did not mean to imply that the difference in price was wholly unjustified. I understand that there would be a similar certification process and extra R&D expenses even if the hardware is identical, and that those expenses would be spread out over a smaller user base. Still, if I needed an S9 Adapt, I would probably be frustrated at the additional expense if I knew that the only difference was firmware.

Pugsy wrote:

palerider wrote:she's got two listed in her profile, the auto sv from pr, and the vpap adapt from resmed.

No. I am using only 1 ASV machine which is the S9 Adapt SV.

my mistake, I thought you'd been messing around with both asv units

The Latinist wrote:Does anyone know if there is actually a physical difference between the APAP, Bi-level, and ASV machines? Or is it just a software difference that people pay through the nose for?

see below

JDS74 wrote:I've always suspected that the difference is in the firmware in the machine.
All the things that have to be measured for it to work also have to be measured in an auto BiPap machine as well.

A quick look at the fan and the circuit board would be enough if they are the same.

Anyone willing to sacrifice their ASV for that experiment? It might turn out that it wouldn't be possible to reassemble the machine afterwards into a working machine.

I've taken apart a S9 elite, vpap auto, and a vpap adapt.

they are *identical* physically. in fact, I swapped the squidgy silicone bits from the elite into an adapt that was REALLY gnarley with ciggy smoke, because the person that needed the adapt is very sensitve to smoke smells.

someone posted a teardown somewhere, and I did a (imho) better teardown set of pics recently, if you've got a long T10 driver, and a flat tool to unlatch the clips, (there are clips in the four rectagular slots on the bottom) they come apart, and go back together quite easily.

palerider wrote: my mistake, I thought you'd been messing around with both asv units

No problem. I tend to always be messing around with something and the 960 PR S1 is next on my list but it will take me a while to stumble across one that I can afford. Someone was kind enough to make me an offer I couldn't refuse on the used S9 Adapt that I got or I couldn't have tried it.
It will have to be the 960 though. I have got spoiled with the heated hoses on these machines so I don't want to have a 950 model unless it was free and fat chance of that ever happening.
To be clear...I am not unhappy at all with the S9 Adapt SV model 36007...I don't need that extra auto EPAP that comes on the 36037 model anyway. I am just curious about how the 960 feels just because I am a curious type of person. I try to scratch the curiosity itch when I can.