Thank you for the replies. This is very helpful. I'm always interested in learning more. avi123, good observation about the results you experienced from using a different mask. The AHI number must be of some significance. Otherwise, I wouldn't think the manufacturers of the machines would bother to ...

I have a Resmed S9 machine and have had it for some time. The 1st two technicians at the DME provider in Seattle were incompetent in showing me how to use the machine and to be able to set the readings on the machine. Finally, a "real nurse" showed me how to display the AHI and other settings. I did...