(01-16-2017, 08:34 AM)under pressure Wrote: Every manufacturer uses their own proprietary software and algorithms in their machines. You will never see exactly the same AHI reporting results from different brands, and there might even be some statistically significant differences.

I too have an S9, an Airsense 10, and also a Z1 Auto for my travel use. These machines (ResMed & HDM Z1) could not be more different in most aspects. The ResMed is by far the more sophisticated machine both in operation and event recording, so I use the ResMed data as my baseline, and the data from the Z1 just as a reference.

I experience basically the same thing you are reporting, my ResMed machines both want to settle on a higher pressure, and they both report more events than the Z1. Personally I treat the Z1 as such a different animal that I set it up somewhat differently than I do the ResMeds. I tend to run the Z1 a couple centimeters higher on the minimum pressure setting in order to get similar therapy from it compared to the ResMeds.

One glaring example of the difference between the machines is that the ResMed uses an FOT technique to differentiate between an obstructive event versus a clear airway event (central apnea) and will report each separately. The Z1 has no such capability, it lumps all apneas into the same bucket and therefore has no ability to breakdown the events into obstructive or clear airway. This is just one example that would lead one to use the ResMed as your more accurate baseline machine and take the data reported from the Z1 with a big grain of salt.

I love the Z1 for it's small size as sometimes I have very limited packing space. It breathes ok now on the most recent version of the Z-Breath function (I like it best on number 2) -- the downside is the noise produced by the small, high velocity turbine it uses, and of course I would not depend heavily on the sleep data it reports. It's only real benefit is the diminutive size when packing space is very limited.