Newbie requests help choosing APAP: PR1 or S9?

[cowlypso]

Are you talking about Mask Resistance setting?
If so, this is not the same thing as ResMed's mask fit thing.
I have clinician manual for PR S1 Auto and I have seen nothing about mask fit.

From the provider guide (maybe different from the clinician manual?), page 4: "Mask fit check: You can enable or disable the mask fit setting if it is available on your device. If this feature is enabled, it allows the patient to check the fit of their mask prior to starting therapy. This is done by measuring the amount of leak in the patient circuit." There is a completely different paragraph about mask resistance setting, they are two different things.

Maybe your particular model doesn't have this feature? I definitely have the mask fit check option in my clinician menu on my machine. My machine is a PR S1 Auto REV 01, manufactured February 2011.

[Pugsy]

Maybe your particular model doesn't have this feature? I definitely have the mask fit check option in my clinician menu on my machine. My machine is a PR S1 Auto REV 01, manufactured February 2011.

Yep, my machine is last year model. I realized this had been added to the very latest model right before I went to bed last night an I forgot to edit my post.

[dtsm]

Either brand should do a very good job for you. When it comes right down to it, which brand of machine you decide on isn't going to be anywhere near as important as finding a mask that suits you well. The mask will be the main key to being able to actually sleep while using any CPAP/Autopap/WhateverPap. Of course, one does have to have a machine, and it looks like you're doing your research very well!

Rested Gal says it best [as always!]. The key to successful therapy is compliance, and the key to compliance is finding the 'perfect' mask. The alarm might sound important but as others have mentioned, once you've been on therapy for a while, it'll probably never be used.

[robysue]

* The S9 is designed a little more with comfort in mind; the PR1 a little more with preventing apnea events. The PR1 puffs a little harder to keep the airway open after exhalation. This might wake some people. The S9 might miss a small number apnea events, but might be easier to sleep thru. It probably depends a lot on the individual. For some people, it might not make much difference.

You've got the gist of it , but there are actually two different things here. The puffs are diagnostic pulses used to check if your airway is open. PR1 uses a single 2cm pulse that bothers some people, though in Rev 1 this was softened and bothered fewer people. Now I think they're on Rev 3, so do your homework. S9 uses a smaller, oscillating series of pulses that very few can detect even when awake.

I'm not sure that I believe the S9 is somehow designed more with comfort in mind and the PR S1 is designed more with an eye to preventing apneas events. Comfort is in the airway of the user and there is more than one legitimate idea on how to prevent apneas.

The S9's auto algorithm is particularly aggressive in increasing the pressure in response to apneas but also in response to snoring and flow limitations, which are thought to be precursors to airway collapse. For some people those rapid increases in pressure DO cause comfort problems---both with arousals and with aerophagia. And the S9 is also very slow to reduce the pressure back down. The System One's algorithm has it's own comfort problems, but its hunt-and-peck algorithm, for all its flaws, usually means the PR S1 is often able to respond less aggressively in terms of rapid pressure increases while at the same time allows it to reduce the pressure back down more rapidly. And for SOME people, the average pressure level is a major issue in over all comfort of sleeping with the machine.

As for pressure pulses vs. oscillations, I have to speak for the minority: There ARE some folks who are driven batty by the S9's oscillations and who aren't bothered by those 2cm puffs on the System One. I'm an example of such a person. For me, the key is that the puffs, though large are short lived. The oscillations start and keep on going for several seconds at a time.

I'll be honest, I don't know if my S1 BiPAP Auto is a Rev 2 or Rev 3: It was manufactured in April 2011. So it's possible that my machine's pressure pulses are the newly revised ones that are harder to detect. Anybody want to let me know how to tell?

When using exhalation relief, the S9 waits for you to inhale before bring the pressure back up to full, thus risking an OA if the pressure hasn't been raised to compensate. The PR1, OTOH, will bring the pressure back before you're done exhaling, thus risking driving you up a tree because you feel like the machine is trying to make you breathe faster.

Of course, both EPR and Flex can be turned off if they are really problematic.

For me? I can't stand Flex for exactly this reason---it feels as though the machine wants me to inhale before I'm done. However, I also felt that way when I was using the S9 AutoSet with EPR set to 2 or 3 and EPR=1 didn't seem to provide enough relief for me.. The "rushed" feeling was not as pronounced as it is with flex, but it was indeed still there. And to me, it seemed as though the S9 brought the pressure back up just before I was starting to inhale. Others will quibble with this, but I'm simply reporting how it felt to me.

* Does anyone have any idea whether the S9 would be more likely to prevent aerophagia?

Given the the mini-bilevel style exhalation relief, I think it would. But if you really have trouble with aerophagia, you may need a true bilevel machine, and then you'll be glad you got the cheaper one on the first go.

Again, reporting for the minority: Some folks DO have aerophagia problems with the S9---particularly when running in Auto mode because the S9's Auto algorithm is designed to rapidly increase pressure up whenever it detects clusters of apneas OR snoring OR flow limitations. And it's slow to bring that pressure back down. Both the rapid rise in pressure and the slowness to bring the pressure back down to the minimum pressure settings can be problematic for some aerophagia sufferers.

To be fair, the System One's algorithm's hunt-and-peck algorithm can disturb some folks as well as create some aerophagia problems since the pressure is allowed to increase even if there are no obvious events to respond to. But overall, the System One increases pressure less rapidly than the S9 and it reduces pressure back down to the minimum settings more rapidly the S9.

Which is best for a sensitive stomach? That really depends on the individual. And there's really no way to tell until you try breathing with the machine for at least a night or two.

As for whether a bi-level will really be needed to address aerophagia issues: Maybe, maybe not. In my case, switching from the S9 AutoSet to the System One BiPAP was critical in finally getting my aerophagia problems down to being bearable on a daily basis, and even largely eliminating them. And my aerophagia problems occurred at low pressure levels on both CPAP/APAP: I found aerophagia intolerable even when I was running the S9 in Auto with a range of 7--8cm with EPR = 2. Right from the start, I found using my BiPAP in straight BiPAP mode at 8/6 much easier to tolerate AND it did provide some significant relief for the aerophagia, even though aerophagia remained somewhat problematic until I switched to Auto BiPAP mode. And yet, conventional wisdom around here says the S9 at 8cm with EPR=2 should effectively feel like a bi-level running at 8/6. So why was it easier for me to tolerate the System One BiPAP at 8/6 than the S9 at 8cm with EPR=2? I have tried to explain it in other threads, but it remains difficult for me to articulate why EPR doesn't feel like real bi-level to me.

*

Any other thoughts you may have are more than welcome.

Sounds like you've done your homework. Unfortunately, it's very hard to tell which is best for you without trying them both. In your position, I went with the S9 because almost no one reported having to abandon it, while there were a few who couldn't tolerate the PR1.

I could not tolerate the S9 and did have to abandon it. But in spite of that, I don't regret my original decision. While I'm happy (enough) with the System One BiPAP, I'm pretty sure I would have had as many problems with the System One Auto as I did with the S9. The problems would have been different, but in the end, I still believe I would have needed the switch to a bi-level to stand a chance of developing a tolerance for xPAP therapy---a tolerance that I am still working on fine tuning, by the way.

[Otter]

When using exhalation relief, the S9 waits for you to inhale before bring the pressure back up to full, thus risking an OA if the pressure hasn't been raised to compensate. The PR1, OTOH, will bring the pressure back before you're done exhaling, thus risking driving you up a tree because you feel like the machine is trying to make you breathe faster.

For me? I can't stand Flex for exactly this reason---it feels as though the machine wants me to inhale before I'm done. However, I also felt that way when I was using the S9 AutoSet with EPR set to 2 or 3 and EPR=1 didn't seem to provide enough relief for me.. The "rushed" feeling was not as pronounced as it is with flex, but it was indeed still there. And to me, it seemed as though the S9 brought the pressure back up just before I was starting to inhale. Others will quibble with this, but I'm simply reporting how it felt to me.

I've seen one or two other posts describing this, don't remember if they were yours or not. It's really odd that it felt that way because the S9 doesn't increase pressure until you start to inhale. I'm sure of this because I spent a long while one day looking at my traces with the timescale stretched out. I wonder if the rushed feeling comes from how fast the pressure comes back. I also wonder how you'd do with the extremely customizable waveforms of the DeVilbiss Intellipap. Though they don't log breath by breath data as Philips and Resmed do, from what I've read, I think they're ahead on exhalation relief.

The S9's auto algorithm is particularly aggressive in increasing the pressure in response to apneas but also in response to snoring and flow limitations, which are thought to be precursors to airway collapse. For some people those rapid increases in pressure DO cause comfort problems---both with arousals and with aerophagia.

It doesn't bother me at all when the S9 increases pressure, though I do notice it sometimes if I'm awake. I don't think it disturbs my sleep, but without an EEG, it's hard to tell.

And yet, conventional wisdom around here says the S9 at 8cm with EPR=2 should effectively feel like a bi-level running at 8/6. So why was it easier for me to tolerate the System One BiPAP at 8/6 than the S9 at 8cm with EPR=2? I have tried to explain it in other threads, but it remains difficult for me to articulate why EPR doesn't feel like real bi-level to me.

I've noticed that the S9 just touches IPAP and EPAP as I breathe. I'd expected it to get there earlier in the breath and stay there, but usually just the top of peaks and the bottom of the troughs reach the target. Is that how your bilevel works?

[Languid]

Everyone:

I've read through everyone's comments more than once, and am considering it all carefully. It's been important for me to hear how different people's experiences may vary considerably. All of this gives me a lot to think about. Of course, I'll continue to follow this thread if more is posted. I haven't thanked each of you by name, but every one you has been a tremendous help by posting. Thanks, all.

[Knightmare]

I also have both the PRS1 and the S9. My PRS1 is over a year old so, undoubtedly its the older version. Not really sure if you could go wrong picking either unit but if I had to pick a single unit, I would pick the S9.

What I like about the S9 over the PRS1:
-Quieter
-Climateline Heated Hose
-Much more detailed information available on color LCD
-Smaller Footprint
-more visually appealing to me
-Nice tray that locks in air filter (stupid PRS1 filter always fell out for me)

What I like about the PRS1 over the S9:
-Humidifier Chamber is easier to see how much water is left

One note, I had a rough time switching from the PRS1 to the S9. CFLEX is quite a bit different than EPR. I struggled with the change, and actually considered going back to the PRS1. It took me a few restless nights to adjust. Now I sleep comfortably with either machine.

Hope this helps.

[Languid]

From what I'm reading on this thread, people have different reactions to these machines. For some, S9 works best; for some, PR1 works best; and for many, either machine works fine.

At this point, I'd like to try the S9. But I think it makes to rent it first and see how it works for me. I could use any suggestions on where to rent from, but I'm going to post that question as a separate thread.

[robysue]

When using exhalation relief, the S9 waits for you to inhale before bring the pressure back up to full, thus risking an OA if the pressure hasn't been raised to compensate. The PR1, OTOH, will bring the pressure back before you're done exhaling, thus risking driving you up a tree because you feel like the machine is trying to make you breathe faster.

For me? I can't stand Flex for exactly this reason---it feels as though the machine wants me to inhale before I'm done. However, I also felt that way when I was using the S9 AutoSet with EPR set to 2 or 3 and EPR=1 didn't seem to provide enough relief for me.. The "rushed" feeling was not as pronounced as it is with flex, but it was indeed still there. And to me, it seemed as though the S9 brought the pressure back up just before I was starting to inhale. Others will quibble with this, but I'm simply reporting how it felt to me.

I've seen one or two other posts describing this, don't remember if they were yours or not.

Most likely some of them were mine. Way back when there was a long discussion between myself, jnk, and -SWS with wonderful graphics by -SWS about exactly when the S9 Elite/AutoSet start raising the pressure back up. By the end of that discussion -SWS had even done some of his graphics magic on an EasyBreathe wave for for the S8 VPAP Auto and had discovered that there was a very small difference in the timing of the initiation of the rise back up to full pressure between the S9 Elite/AutoSet EPR "Easy Breath" wave form and the VPAP's. The S9 CPAP/APAP EPR wave form was smoother, but the initial, very subtle rise in pressure was a few FRACTIONS of a second earlier on an APAP with EPR than the VPAP's sharper transition, which has a distinctive "corner" before the increase in pressure begins. The relevant figures were on page 3, but they're no longer there for some reason. The links to the figures are supposed to be at

Resmed VPAP picture and Resmed Auto Set with EPR=3 picture

but the links seem to be broken now.

It's really odd that it felt that way because the S9 doesn't increase pressure until you start to inhale. I'm sure of this because I spent a long while one day looking at my traces with the timescale stretched out. I wonder if the rushed feeling comes from how fast the pressure comes back. I also wonder how you'd do with the extremely customizable waveforms of the DeVilbiss Intellipap. Though they don't log breath by breath data as Philips and Resmed do, from what I've read, I think they're ahead on exhalation relief.

I know that everybody SAYS that the S9 doesn't increase the pressure back up until after you start to inhale. But that is NOT what it felt like to me. Part of my particular problem is that I may psychologically interpret a certain very flat part of the breath wave form as "end of exhale" when the machine (and most people) think of it as "beginning of inhale"---because that's where I would notice it and where it would bother me: There's a slight pause between the most active parts of my exhales and an inhales where the flow wave form is both very flat and very close to 0. This part of my breathing pattern feels like it's still part of the exhale to ME. But it was during that flat part of the wave form---when little or no air was going in or out of my lungs---that I would notice the S9 starting to increase pressure when EPR was turned on. And I will admit there ARE times that my S1 BiPAP misinterprets my breathing pattern and starts the increase in pressure sooner than I'd like it too. But it's not every breath; it's only the occasional breath and very seldom does it happen for two or three breaths in a row.

Now, could it be that I was reacting to the speed of the rise in pressure on the S9? I suppose that might be true---particularly since I prefer the Rise Time = 3 setting on my current BiPAP. That Rise Time setting means that it takes the machine 400 msec (about .4 seconds) to increase the pressure from EPAP to IPAP on each of my inhales. That's the longest option for the Rise Time setting, and I have a pretty strong preference for that setting.

And yet, conventional wisdom around here says the S9 at 8cm with EPR=2 should effectively feel like a bi-level running at 8/6. So why was it easier for me to tolerate the System One BiPAP at 8/6 than the S9 at 8cm with EPR=2? I have tried to explain it in other threads, but it remains difficult for me to articulate why EPR doesn't feel like real bi-level to me.

I've noticed that the S9 just touches IPAP and EPAP as I breathe. I'd expected it to get there earlier in the breath and stay there, but usually just the top of peaks and the bottom of the troughs reach the target. Is that how your bilevel works?

I do understand what you mean when you say the peak "IPAP" (i.e. therapeutic pressure setting) and the min "EPAP" (lowest exhale relief pressures) feel like they are barely touched on each breath with the S9 EPR system. In other words, it feels as though the pressure is changing throughout the entire breath sequence with the S9 with EPR turned on, and the published pressure wave form backs this up.

But when I use my PR System One BiPAP, it sure doesn't feel that way at all to me. And the published wave forms from Resprionics for both Flex and Rise Time simply don't have that characteristic peak and trough look of the Resmed EPR Easy Breath Wave Form.

This is the best I can do to describe HOW the System One BiPAP actually FEELS when I use it without Flex and with Rise Time:

• As soon as I start to exhale, the pressure drops suddenly and completely down to my EPAP level. It's a SHARP transition from IPAP to EPAP and it feels essentially instantaneous.
• The pressure STAYS CONSTANT at the EPAP level for the ENTIRE exhale and the ENTIRE flattish part of my breathing pattern (except for those rare breaths where the machine doesn't track my breathing correctly).
• When air is CLEARLY starting to move into my lungs, the pressure is raised up to the IPAP in 400 msec and then it STAYS at the IPAP until I start to exhale. This transition from EPAP to IPAP feels a bit sharper than the transition in the S9 with EPR = 2 or 3, but it also occurs at a time when my mind says "I'm breathing in" and the sharpness of the transition does not bother me---it's rather like the transition to taking a deep breath without the CPAP.

The net result is that instead of the curvy peaks and troughs of the Resmed EPR pressure wave form, the pressure wave form on my BiPAP being used without Bi-Flex and with Rise time looks like a modified square wave form where the slanted rising pressure lines take place over .4 sec:

Code: Select all

         ______         _______         ______        _______
|       /      |       /       |       /      |      /      |
|______/       |______/        |______/       |_____/       |

Now, don't get me wrong: I think plenty of folks find the EPR Easy Breath wave easy and natural to breath with. But I didn't. Why? Well, I ascribe it to me just being in the minority of people who DON'T find the EPR Easy Breath Wave Form as more natural to breath against. Maybe it's simply that the pressure is always changing throughout the whole breath period on the S9 with EPR turned on. All I know is that for me, I find the PR System One BiPAP with RISE TIME (not Bi-Flex) more natural to breath against than I found the S9 AutoSet with EPR on.

And finally, for what it's worth, I think that many folks probably can't tell much difference between Flex and EPR and BiPAP---at least when the difference between IPAP and EPAP is less than or equal to 3. And those that can tell the difference? My guess is that many of them will probably find that they prefer the system where they were first able to adjust well to xPAP therapy and start feeling its benefits. For most newbies, I think that will be whatever system they start out on. For a few unlucky folks like me, it will take a change in machine to find out what they really need.