REMstar Auto M Series versus ResMed S9 AutoSet

[lahlah1]

After 6 years of using a REMstar Auto M Series machine (every night), it was beginning to make a lot of noise, so I went back to my provider and got a new ResMed S9 AutoSet. Both include an attached humidifier. My one and only sleep study (6 years ago) measured my AHI at around 11. My wife measured it as loud and sleep-depriving (to her).

Here is my question: the REMstar machine almost always measured my AHI at around 5.0 (ranging from 4.5-5.5). The ResMed machine, after a month, measures it at 1.42. Subjectively, I don't notice much difference (at least not one that I can guarantee is not psychosomatic, given my knowledge of these data). Has anyone else noticed such a difference between the two machines in terms of AHI measurement or control? If so, could it just be a side-effect of different measuring algorithms, or do you think that the ResMed could be so much more effective?

[archangle]

After 6 years of using a REMstar Auto M Series machine (every night), it was beginning to make a lot of noise, so I went back to my provider and got a new ResMed S9 AutoSet. Both include an attached humidifier. My one and only sleep study (6 years ago) measured my AHI at around 11. My wife measured it as loud and sleep-depriving (to her).

Here is my question: the REMstar machine almost always measured my AHI at around 5.0 (ranging from 4.5-5.5). The ResMed machine, after a month, measures it at 1.42. Subjectively, I don't notice much difference (at least not one that I can guarantee is not psychosomatic, given my knowledge of these data). Has anyone else noticed such a difference between the two machines in terms of AHI measurement or control? If so, could it just be a side-effect of different measuring algorithms, or do you think that the ResMed could be so much more effective?

Different machines often give different AHI results, even with the same settings.

I think there are "a lot of smarts" in how the machines measure apneas, and when you have apneas that are borderline in terms of being long enough or deep enough to count, the machines may differ in terms of whether they "score" an apnea or not, even given the same data. They probably score "big, bad, apneas" the same, but may differ on the small stuff.

The S9 AutoSet may very well be doing a better job controlling your apneas as well. There's "a lot of smarts" in the way that different machines adjust the pressure as well. S9 machines in particular are very good at detecting problems and adjusting the pressure before you actually have apneas.

[Pugsy]

Welcome to the forum.

Even people going from the older ResMed S8 series machines to the S9 machines have reported rather dramatic differences in AHI.
It's a newer more improved algorithm when compared to the older machines.
Each brand has their own way of doing something and some people's bodies might happen to like one way over another way better.
It's difficult to compare the 2 brands even when comparing newer technology to new technology and even harder to compare one brand's older technology to another brands newer technology. Kinda like trying to compare apples and oranges.

I do think that the S9 machine is going to respond a little quicker when in auto adjusting pressure mode and that might account for the lower numbers.

[lahlah1]

Thanks for the replies, pugsy & archangle.

Yeah, I kinda figured it might be an apples and oranges situation, but I was curious if anyone else had noticed it. I have to say that so far that I do like the ResMed more than the older Remstar; it's more adjustable, and it does seem to be "gentler" to use. I can also see the detailed data in the free SleepyHead program, which is nice.

I'm wondering if the humidifier is actually working, however, since even when I request a temperature of 85 degrees (just to test it), the heater does not seem to be on.