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TOF wrote:The CPAP's sensors are in the machine and can only provide information on the air as it leaves the machine. Since this device is placed between the CPAP and the user, the sleep data generated is totally bogus. The degree of this skewing is impossible to calculate.

I'm pretty sure this is all wrong, but need the Oscar files to prove it.

Rubicon wrote: ↑

Fri May 05, 2023 7:28 am

TOF wrote:The CPAP's sensors are in the machine and can only provide information on the air as it leaves the machine. Since this device is placed between the CPAP and the user, the sleep data generated is totally bogus. The degree of this skewing is impossible to calculate.

I'm pretty sure this is all wrong, but need the Oscar files to prove it.

How is it wrong? Where are the sensors placed in your system? OSCAR data comes from the very same sensors at the machine end. Both my machines have hose size adjustments to compensate for the pressure drop across the hose, but neither has a flow restrictor entry.

stevenal wrote: ↑

Fri May 05, 2023 9:25 am

How is it wrong?

Well, right off the bat in re:

The CPAP's sensors are in the machine and can only provide information on the air as it leaves the machine.

V-Com restricts flow, so in fact, the sensors should be accurate as some air would not "leave the machine".

Oscar files would be helpful to see what the restrictor does to pressure and flow, so a comparison w/ and w/o should prove helpful.

My guess is that it's going to look like adding Rise Time and decreasing delivery pressure slightly.

Also, has to be Oscar, can't be SleepHQ.

And also measure unrestricted flow through that thing. Cause don't forget you have an intentional leak of ~30-40 LPM. If that thing restricts flow to nearly intentional leak (and I wonder if that's why people are complaining that it's hard to inhale) one wonders if CO2 washout is as efficient as w/o the device. That said, too much CO2 washout may be bad, so in a small subset can this thing be beneficial by messing everything up?

Although these machines are capable of delivering ~160 L/M, they only send out what's necessary to maintain pressure. If leak reduction occurs because there's no longer enough flow to generate a LL, then all it really does is save humidifier water.

Need some data to counter WAGs...

Rubicon wrote: ↑

Fri May 05, 2023 10:28 am

And also measure unrestricted flow through that thing. Cause don't forget you have an intentional leak of ~30-40 LPM.

So the company says "Yeah there's some flow loss, but not too much, don't worry about it":



Seems to me that if someone is inhaling @ 30-50 L/M, and 30-40 L/M is going out the intentional leak vent, the machine will have to send in 60-90 L/M to maintain pressure and flow. And if that's the case, in actuality the pressure loss will be much greater than their little table suggests.

So IDK if it's totally "bogus".

How about "NFI"?

Rubicon wrote: ↑

Fri May 05, 2023 10:48 am

Rubicon wrote: ↑

Fri May 05, 2023 10:28 am

And also measure unrestricted flow through that thing. Cause don't forget you have an intentional leak of ~30-40 LPM.

So the company says "Yeah there's some flow loss, but not too much, don't worry about it":



Seems to me that if someone is inhaling @ 30-50 L/M, and 30-40 L/M is going out the intentional leak vent, the machine will have to send in 60-90 L/M to maintain pressure and flow. And if that's the case, in actuality the pressure loss will be much greater than their little table suggests.

So IDK if it's totally "bogus".

How about "NFI"?

I'm interested in the following, "V-Com is added between the CPAP mask and the CPAP hose and is engineered to reduce inspiratory pressure and flow to provide comfort with minimal to no reduction in expiratory pressure (EPAP). After weeks or months when the patient can easily tolerate the peak flow and inspiratory pressure of PAP therapy, the V-Com can be removed from the circuit."

Assuming this is accurate, wouldn't the EPAP be higher than IPAP for someone who's using CPAP?

Rubicon wrote: ↑

Fri May 05, 2023 9:59 am

stevenal wrote: ↑

Fri May 05, 2023 9:25 am

How is it wrong?

Well, right off the bat in re:

The CPAP's sensors are in the machine and can only provide information on the air as it leaves the machine.

V-Com restricts flow, so in fact, the sensors should be accurate as some air would not "leave the machine".

Oscar files would be helpful to see what the restrictor does to pressure and flow, so a comparison w/ and w/o should prove helpful.

My guess is that it's going to look like adding Rise Time and decreasing delivery pressure slightly.

*flow* shouldn't be wrong, but the measured pressures are all going to be wack... Now if the person had one of the old ASVs that had a pressure measuring tube connected to the mask, that might be reasonable, doubt the machine could compensate though.

Callen wrote: ↑

Fri May 05, 2023 11:18 am

Assuming this is accurate, wouldn't the EPAP be higher than IPAP for someone who's using CPAP?

That's what they're touting as the genius revolutionary paradigm shifting discovery!

We need to find an old Adapt SV and monitor at the patient in CPAP Mode, after the V-Com:

In lieu of the $35 V-crap, why not insert a $4 AB filter?
At least, there is a SETTING for the AB filter.
You could even daisy-chain 2 or 3 of them for the same result--only cleaner.

Rubicon wrote: ↑

Fri May 05, 2023 1:52 pm

We need to find an old Adapt SV and monitor at the patient in CPAP Mode, after the V-Com:

You can just hook up a differential manometer at the machine and at the mask. I did that some time back while playing with the AB filters and 3 meter hoses, what I found was that on a deep breath the pressure at the machine was as much as 10cm different than the pressure at the mask, but the pressure at the mask was spot on for what the machine was set to.

Just to wrap some things up. V-COM sent me a postage paid return shipping label and I just got all my money back in my checking account. I can't ask for anything more. No scam here.

Actually, I did learn a thing or two. OR confirm a thing or two. Quit using APAP and keep using the mouth tape.

I don't understand how anyone was expecting this to work or, more to the point, what they expect it to do, exactly.

ILoveFlowers wrote: ↑

Thu May 11, 2023 11:30 pm

I don't understand how anyone was expecting this to work or, more to the point, what they expect it to do, exactly.

That’s easy. Just go on YouTube and do a search. LOL