Un-happy face sleep report

[RichardVT]

I ran the test on my machine. I lost track of all the segments of counting, however when an open tube showed a red smiley, closing the end completely resulted in a green smiley the majority of the time within about two seconds and frequently less than one second.

On two or so occasions, I had to count to as much as five seconds before the red smiley went back to green. That was with my machine and pressures set as shown in my profile.

I did notice that, if I seemed to let the pressure build, so to speak, while on green, it seemed to recover more quickly than if I didn't let the pressure build so much, even though each time I began the open tube a green smiley was displayed, i.e., I could hear more air rushing those times that I left the green smiley up longer before uncovering the tube.

Also, the time it took an opened tube to turn red seemed to be longer after letting the pressure build while on green. Likewise, if I opened the tube the instant it turned green, the smiley would turn red nearly immediately!

[Sleeprider]

The only leaks I detect are around the circle of little holes where the hose swivel/valve assembly connects and at the holes where the valve that allows the patient to breath when machine stops delivering air. I have tried two masks and both 6 foot and 10 foot hoses, each showing the same problem.

That's it.  The leak at the antiasphyxiation valve is not supposed to happen during operation.  It is leaking due to a faulty valve.  My mask shows no leak during full pressure testing. I'm not sure what you're saying about the mask fit having random numbers.  Mine just shows the good fit and a smilie unless I intentionally allow a leak.

[Gideon]

FYI 
you can see your actual leak rate during use by turning the knob until you see see the leak rate displayed under the green pressure bar.  There is a lot of additional info that is displayed, leak rate being one of them.
I find that better than looking for the happy face, especially after you initially set the mask.

[Joe Fox]

It looks like RichardVT's machine  is a little more rhythmic than mine but as the pressure presented in the mask fit adjust may be dependent on the settings for the patient and buildup may be different. Not enough data yet.

I will look at the leak rate display while under use (if I can see it with my glasses over the mask) by trying the knob turn as Sleeprider mentioned. I can feel a little air from the swivel/ antiasphyxiation valve and it is about the same as I have noticed for the last 18 years. It's not much air and to me, the indications of 7, 8 and 10 seconds after closing the tube end before the red face turns green does not support that much of a loss is causing the problem. Especially when the mask is out of the loop.  Isn't 40 L/min a lot of air? Joe

[Joe Fox]

Sleeprider wrote:  "I'm not sure what you're saying about the mask fit having random numbers.  Mine just shows the good fit and a smilie unless I intentionally allow a leak."

I was running the mask fit adjustment option from the options menu, which I am assuming is full or set max pressure, without the mask connected. The machine presents a constant pressure so you normally will adjust the mask fit for no leaks. But I disconnected the mask and with my thumb over the end of the hose, blocked the airflow, then counted  the seconds it took for the Red un-happy face to turn to a Green happy face. I then uncovered the tube allowing the air to escape so that the face turns back to a Red un-happy face, waited two seconds, then started over again. The time it took to change from Red to green in seconds was recorded an were as follows. 2 seconds, 5 seconds,2 seconds, 2 seconds, 2 seconds, 4 seconds, 2 seconds, 4 seconds, 4 seconds, 5 seconds, 4 seconds, 7 seconds, 3 seconds, 7 seconds, 2 seconds, 8 seconds, 8 seconds, 8 seconds, 10 seconds, 10 seconds, then the mast fit adjust routine self terminated and the machine resumed normal BIPAP operation. Random number of seconds to recover from an open circuit seconds in the range of 2 to 10 seconds, seems random to me. RichardVTs test results show most within two seconds with a majority less than two seconds to change to green.

[Joe Fox]

So here's the facts! I received my new mask yesterday, a ResMed AirFit F10, containing a new antiasphyxiation valve and swivel assembly, and headgear complete with a User Guide. Also a new 10 foot hose. After a night of use I still have the un-happy face for mask fit; so I guess there is something wrong with my new Aircurve 10 Vauto BiPAP machine.

My use of the term, "leaking a little around the swivel", was relative. Here is the relevance. I draw your attention to the User Guide. First under a listing of “General Warnings”, on page 2, first paragraph, “...Explanation:CPAP and bilevel devices are intended to be used with special masks (or connectors) which have vent holes to allow continuous flow of air out of the mask. When the device is turned on and functioning properly, new air from the device flushes the exhaled air out through the mask holes.”...
On page 7 you will find under Technical specifications and to the right of the Paragraph heading “Pressure-flow Curve”, you will find; “The mask contains passive venting to protect against rebreathing. As a result of manufacturing variations, the vent flow rate may vary.”
What that means is there is a circle of little bitty holes as spotted by poster RICHARDVT, that allow the CO2 enriched exhaled air to be flushed from the mask before the patient inhales their next breath. Also, this page has a graph and data points for a moderately linear graph of the volume of air escaping from these vent holes [all the time].
In my case, as much as 32 Liters per minute (L/min) of air flow is vented from the mask, based on 8cmH2O minimum prescribed pressure. Some of the data points follow:
Pressure    Flow
(cm/H2O)  (L/min)
3                 19
4                 22
8                 32
10               37
12               41
16               48
20               54
24               60
28               66
30               69
an there are more.


Joe

[RichardVT]

I concur, it sounds like the machine to me!

[Joe Fox]

Believe it or not!
After two nights with the new mask and looking at un-happy faces in the mornings, I am now getting a Green Happy face. Two mornings running( after 12 days). I guess these automatic machines automatically fix themselves.  Go figure. Thanks guys. Joe

[RichardVT]

Good, glad to hear it works!