Hybrid Mask Revision info w/pics

[Nodzy]

Ok, to settle some disagreement on the Hybrid revision information, I've offered several shots of the passive exhalation port vent rate charts -- one for Revision-B and one for Revision-C.

I hope this helps to make things easier to understand. I'll resize the images, reload them to my domain, and direct the new shots to here after I get some other pressing matters handled.

The Hybrid has undergone several revisions: one being the headgear upgrade to a better design, and the other is a change in the mask shell (the rigid, clear part that the seals and headgear straps attach too).

Between the maker, marketers, associates and distributors there is much confusion about whether or not there have been revisions, and what the revisions are.

It is my understanding, after many phone calls and receiving a FAX or two, that the shell indeed underwent a fast revision to downsize the passive exhalation ports in order to yield more in-mask backpressure. That was needed in order for the mask to work better with EPR, A-FLEX and other units, and low-end pressures.

In the shots below you can see that the passive exhalation vent LPM rates differ at equal pressures on the two shell revisions. The Revision-C has a considerably lower vent rate.

[CVANCE]

Hello,

My name is Christianna Vance and I am the product manager for sleep therapy at Teleflex Medical, representing the Hybrid mask. I had a chance to speak with a customer today who was asking for clarification regarding the email trail below.

For clarification, we have indeed made changes to both the headgear and exhalation ports on the Hybrid. The headgear upgrade became effective in November 2006 and the change to the exhalation ports became effective in December 2006. There have been no other product changes to the Hybrid since December 2006. The versions on the instructions for use manual (REV A,B,C,D,E) have to do with any change that have been done to theinstruction manual. Revision B represents the change in the manual that references the headgear and Revision C represents the change to the exhalation ports. All other Revisions (D,E etc.) have nothing to do with the actual product, rather changes that have been made to the instuction manual itself (change in address, phone number etc).

I hope this isn't too confusing. Please know that we have been providing the most up to date Hybrid product since January 2007 and it is used effectively with all Autopap, cpap and bipap devices.


I hope this clarifies things for you!

Have a great weekend,

Christianna Vance

[jla930]

Christianna,

Are you saying that even if the manual says Revision B, as it does in my case, I still have the new model mask with the revised exhalation ports? I bought my mask just last week from CPAP.com, but who knows how long they've had it in stock.

Thanks,

Jeff

[Nodzy]

Wow... that means that three people I spoke with, who are with the Hybrid mask makers and marketers, told me the wrong scoop. I questioned each about the revision numbers on the box tagging and the manuals, and was assured that the revision numbers related to the mask and headgear changes. I thought that was odd, but assumed that they knew their jobs well enough to not fluff my ears. I've been had.
Very interesting -- almost makes me feel like I was dealing with government bureaucracy.

Either way, the charts do reveal the results of revised exhalation vent port sizing between the earlier version of the Hybrid shell and the current version of the shell.

And, we did stir up a strong wind that brought in an authoritative answer from a person higher up the Hybrid ladder than anyone I managed to speak with.

I'm going back to my corner and being very quiet for a while.

[Snoredog]

based upon those above flow charts, I would AVOID that "B" and prior versions like the plague,

50L/m leak at 10 cm pressure????

That is only about 20L/m higher than the average mask interface out there at the same pressure, most other interfaces at that pressure are in the 28 to 32 L/m range.

What does that higher intentional leak rate translate to?

-higher revving machine making for much more noisy therapy
-possibly lower CO2 retention levels due to higher washout

For example: Using that interface with a Remstar Auto can lead to problems if leak isn't tightly controlled and kept under 75L/m that machine will begin logging Large Leak. When that happens it begins by dropping pressure by 2 cm and will continue dropping until the leak is eliminated. This means your machine has to work overtime in order to compensate for the larger than expected intentional leak flow.

So if your pressure is up in the high teens (i.e. 17 cm to 20 cm), your machine may not be able to deliver full therapy at those higher pressures.

While "C" revision shows much improvement, it remains about 10L/m higher than most other interfaces at same pressure which are again in the 28 to 32 L/m range.

Those of us who have used a Full Face mask in the past know you are going to lose pressure over a nasal interface because you have a moving mandible in the mix creating extra leak.

Since I purchased one of the very first Hybrids out, I assume it was a "A" revision with same flow characteristics as the above "B", explains why I couldn't use it. Think the one I sold was passed around here to 3-4 different people.

[Nodzy]

Yep, Snoredog....

I had compared the Hybrid vent rate charts to the ones for my nasal interface masks, and there is still quite a large difference even with the downsized passive exhalation ports on the Hybrid shell.

Though, I have to admit... I am successfully using the Hybrid now, with A-FLEX, FLEX resistance at 2, no humidifcation, and at 10 to 14cm H2O.

True, so very true, what you stated about the margin for seal leak being diminished with the underlying high passive vent rate of even the revised Hybrid shell. it also narrows the margin for the machine to be able accomodate for those occasional rapid breathing episodes that many have.

Still, after finding that the Hybrid will work with A-FLEX, and does my therapy a passle of good without tape, lip strips or chin straps... I'm going to keep on using the Hybrid.

Thanks for your clarification.

[cpapnewby]

50L/m leak at 10 cm pressure????

That is only about 20L/m higher than the average mask interface out there at the same pressure, most other interfaces at that pressure are in the 28 to 32 L/m range.

While "C" revision shows much improvement, it remains about 10L/m higher than most other interfaces at same pressure which are again in the 28 to 32 L/m range.

Those of us who have used a Full Face mask in the past know you are going to lose pressure over a nasal interface because you have a moving mandible in the mix creating extra leak.

Snoredog,
I think you are wrong. I just looked at the intentional/exhaust leak rate for my F&P HC431 and it is about the same as the new Rev C Hybrid at all pressures.

If you say that the new Rev C Hybrid has a higher intentional leak rate than other NASAL masks out there, I agree with you but that is not a correct comparison. The Rev C Hybrid needs to be compared with other Full Face Masks because they need more CO2 flush out.

Jim