Explain my leaks, please

Can someone explain my leaks in detail, so that I could understand it? The leaks and the total leaks. Are my leaks acceptable? Thank you. I am using Quattro Air FFM.

George

Hi George,

While you are waiting for someone who can explain the concepts alot better than I can, you might want to look at this tutorial by Pugsy by using the "find" function of your internet browser and insert the term "leaks".

viewtopic/t88983/Pugsys-PointersSleepyH ... Hints.html

49er

PR machines use TOTAL leak figures as opposed to Resmed that only show anything above 24 (I think) lpm. When Mark set up sleepyhead he put both lines in, so your total leak of just over 40 using a Quattro at pressures of 12 is great... the low number (2) is if you were using a Resmed machine, you would be way below the problem line. Your leak line is absolutely spot on Gabe.

I have the same pump and mask. The mask is designed to to continuously vent (or leak) a certain amount of air to prevent rebreathing of CO2. I particularly like the venting on the Quattro Air, which is in the intake elbow. The venting is pressure dependent, and at setting 12 is 41 L/min (give or take, depending manufacturing variations). This is about what you're seeing in Sleepyhead, since the Philips reports the total, including the venting. (SleepyHead is guessing at the vent rate to give the "Leaks" entry.) Your actual leak rate is essentially zero; mine tends to start leaking at pressures above 10, so yours must be a good fit. A real leak is 20 or 30 or higher, and when that happens, you will definitely know it.

Total Leak is the masks expected vent rate plus any excess leak. It won't/can't ever be zero since in includes the mask's vent rate.

Leak line..corresponds to the bottom leak line on the graph when you see dual leak lines on the graph....the is an approximation of excess leak only. That data point in SH is not polished or totally finished yet but it's going to be close.


Both leak terms for your night in question point to excellent leak numbers indicating minimal to zero leak.

So GREAT LEAK NUMBERS and nothing to worry about. Damn near perfect.

George,

The "total leaks" data includes both the intentional leak rate built into your mask to prevent rebreathing of CO2 and any excess leakage that is detected. A "good" total leak number should be close to the expected intentional leak rate for your mask at the pressure you are using (plus or minus a few L/min). On page 8 of the Quattro Air's user guide is where you'll find the chart of expected leak rates. At your pressures (12-16.5cm), the expected leak rate is the low to mid 40 range. So your total leak rate numbers, including that max of 43 L/min are excellent.

The "leaks" data is SleepyHead's statistical estimate of how much unintentional leaking is going on. This number is only an estimate, since SleepyHead does not know what mask you are using. But its usually a very good estimate. The fact that the 95% leak rate is 0.0 L/min means that SleepyHead believes there were NO unintentional leaks for 95% of the night. That's EXCELLENT. The max leak rate of 2.0 L/min indicates that even when your leaks were at their highest, there was only very marginal unintentional leaking going on. Again, that's an EXCELLENT max leak rate number.

Thank you all!! Much appreciated!! This the greatest forum!! You made my day!!

George