0 AHI-Is my machine working correctly?

I've had an S9 for about 4 months. My AHI readings have been between .03 and 2.5 nearly every night. For the past five nights, my AHI has been 0.0. My median leak rate/minute is 0 each of those nights and 95th percentile leak rate varies between 7 and 16 L/minute. Pressure is automatically fluctuating between 10 and 12. I'm not sure what the median and 95th percentile numbers mean exactly.

I wear a nasal pillow mask and have had a cold and stuffy nose.I made no adjustments to bring my AHI down. It just went down to zero and has stayed there. Should I have my machine checked out or should I just be happy with the 0 AHI? I'm sleeping well but not any better than when my AHI is above 0. Any suggestions would be appreciated.

Is the software reporting flow limitations and snore?

I don't know if you're just getting exceptional results or if there may be something wrong with your machine, data card, or ResScan. Another forum member just reported that his S9 has been reporting 0.0 AHI every night since June 20. You may want to read his post: viewtopic/t54803/viewtopic.php?f=1&t=54764. Perhaps you'll get some ideas there. I suggest that you look at your Flow Graph, viewed in a small time increment (maybe 5-minute view?), to see if there are any events of greater than 10 seconds duration that were not flagged.

I've been using my S9 Autoset since early June and I've had four zero-AHI nights, but they weren't on consecutive nights. And I don't see any missed events in the Flow Graph data for those nights.

Please post here once you discover what's going on, so we can all learn.

The median (or 50th centile) pressure is the pressure that the machine was at or below for 50% of the night. The pressure was above this number for the other 50% of the night.

Similarly, the 95th centile pressure is the pressure that the machine was at or below for 95% of the night. The pressure was above this pressure for the other 5% of the night.

I used a Quattro face mask last night and came up with an AHI of 7.8 with tons of leaks. That's actually normal for me with the Quattro and it is the reason why I switched away from the Quattro. I wonder now if the machine/software is working correctly after all.

I'll download the newest ResScan software and try to follow the suggestions here although some of them are complicated for me. I appreciate the link to the other similar thread as well as the other responses. I'll keep you posted.

For those of us who repeatedly get a 0 AHI, I found a fix that worked for me. All I did was delete the data from the memory card. I was able to delete the data while on the S9 unit.