Does anyone switch between an S9 and a System One?

I got a Resmed S9 when I started therapy. Later on, I got a System One that I planned to use for travel (the System One, unlike the S9, can be driven directly from a 12V source).

Earlier this week, I finally got to sleep with the System One. And I hated it. Everything about the experience left me off-balance. The air blew differently. The sound was a different pitch. The data was totally incomprehensible. I barely slept and just couldn't wait to get home and go back to my S9.

Has anyone had reason to alternate between these two machines? If so, what did it take you to get used to the differences?

Nobody?

Yes I have both. I use the PR One as a backup and I take it with me on trips when I ride my Harley. The s9 seems to deliver better therapy for me but I could live with the PR one.

I've used both, but don't switch back and forth. Started out with an S9 AutoSet, but when I had to switch to a BiPAP, the PR S1 BiPAP Auto won out over the Resmed S8-based VPAP Auto 25 for a number of reasons that were important to me---one of which was the non-proprietary data card in the S8 VPAP

The two systems do indeed feel very different. Part (most) of that difference for me is the difference between a bi-level machine and an APAP/CPAP.

However these are differences between a PR S1 CPAP/APAP and an S9 CPAP/APAP that could easily explain why the PR S1 was bugging you:

• The two machines' basic noise do seem to be at different pitches. The S9's noise was higher pitched and for me, that meant harder to hear---the slight hearing loss I have is in the upper pitches. The PR S1 does seem to be "noisier" as well. The decibel rating on cpap.com seems to bear this out as well.
  
  There is a decided difference between the way the Resmed EPR algorithm and the PR A-Flex/C-Flex algorithms work. And this difference is quite noticeable if you are sensitive to when the pressure is increased back up to the full pressure. There's some wonderful info and discussion about this on the thread at: viewtopic.php?f=1&t=58773&st=0&sk=t&sd=a . The relevant discussion starts on page 2 and continues onto page 3. Lots of nice graphics courtesy of -SWS, too, that illustrate why some people are going to notice a real difference in the way an S9 with EPR turned on and a PR S1 with A-Flex or C-Flex turned on feels. No doubt in my mind at all that if you like the S9's EPR, you could easily be driven bananas by the PR A-Flex/C-Flex algorithm.
  
  The two machines' auto algorithms are quite different in how they respond to events. That could also be something that was disturbing your sleep with the S1 and cause you to feel like the "air was blowing different". Likewise, the method for determining if an apnea should be scored as an OA or a CA is somewhat different, and that difference too could explain why the air felt different.
  
  The PR S1's on-board data is absolutely pitiful (and confusing) compared to the "long" version of the Sleep Quality report on the S9. For me, since i was switching machines entirely, the solution was getting Encore Viewer (and later Encore Pro for when I really want to see that wave form data and where the S1 scored the events). And using the clinical menu to reset the data to 0.0 every single night so that when I do check the LCD when I wake up at 7:30, the LCD is giving me at least a semi-reasonable approximation of my overnight AHI. The large leak data on the S1's LCD is largely meaningless---if it says 0, since it seems like only insanely large leaks are ever flagged by the S1. I've been using the S1 for just over 50 days and I've NEVER had a "large leak" flagged by the machine---even on a night where I had a massive migraine and adjusted the straps on the FX ridiculously loose. The leak line in Encore for that night showed plenty of leaking that would have been at or near the Red line in ResScan.
  Even with Encore, there's no numerical calculation of the 90% or 95% leak rate. Just the "average" leak rate, and it's not clear if that "average" is the median or the mean for the leak data set. [And there IS a difference and it DOES matter since the two "averages" are not computed the same way and have different statistical meanings.]

As for getting used to the PR S1, you can try these ideas:

• Turn the Flex OFF. First thing I had to do to get used to the S1 was to turn Bi-Flex OFF (Bi-Flex is the bi-level version of A-Flex/C-Flex.) I needed EPR on the S9, but it still bugged me because I would feel that the machine was trying to rush my inhale when it increased pressure. But the "rushed inhale" feeling was late in my in-hale. With Bi-Flex on, I felt the PR S1 was SUPER rushing my inhalations because the increase in pressure back up to the full (EPAP) setting occurred earlier in the exhale portion of each breath.
  
  Reset the data to 0.0 each night. Once 7:00 AM comes, you can at least get an idea of the overnight AHI number. If you need more than that when you are traveling, think about buying Encore Viewer or getting your hands on Encore Pro. Pro is harder to install and slower to run since it's a big and awkward program.
  
  Use some white noise or very quiet music to mask the S1's louder noise. With the S9, I didn't need anything to distract me from the machine's noise. Less than a week after getting the PR S1, I had bought an iHome and I started using it to play Gregorian chant music all night long at a low volume. The chants distract me from the noise whenever I wake up---which is still too frequently, a bit less frequently than I was waking up with the S9. But that's more due to the hard work I'm doing on battling an insomnia monster that moved into my bedroom on night 3 with the S9 at the start of my therapy.
  
  Consider running the PR S1 in straight CPAP mode rather than APAP mode. The two systems use very different auto algorithms. The S9 AutoSet responds (aggressively) to flow limitations, snoring, and OAs, but basically waits until something starts to happen to raise the pressure. In Auto mode the S1, on the other hand, seems to periodically "test" whether a pressure increase is in order. You can see this when folks post APAP data from Encore---there are these little triangles in the pressure graph (about 3 an hour if I'm not mistaken) and each triangle represents a test increase in pressure by something like a full cmH2O (or two?). If you're sensitive to pressure changes, that's bound to be a potential source of sleep disruptions. Likewise, the two machines use a differing kind of "pulse" technology to determine whether an apnea is an OA or a CA. Some folks apparently find the PR S1's "single big pulse" more annoying and more prone to waking them up than the sequence of smaller pulses used by the S9. This hasn't been the case for me, much to my surprise since I would occasionally detect the FOT oscillations on the S9.