Initial Start Pressure of ResMed S9 & EPR

Sorry if I wasn't very clear. Let me try to explain....

Physician wrote:You said: "With EPR off, the S9 is easier to exhale against than the S8, in my opinion, and breathing feels smooth and natural."

With EPR on in the S9, exhalation should be easier than when it is off. This suggests strongly the S9 EPR is either not functioning or is inadequate. Your finding is exactly what I have found.

I said "With EPR off...." I was trying to say that I think the S9's EasyBreathe technology (which has nothing to do with EPR) is improved over the S8 machine.

The EPR is working on my S9 machine. My S9 is definitely reducing the pressure on exhale with EPR set to 3. I can feel and hear it. But I have absolute NO problem exhaling against the pressure on my S9 machine when EPR is off. It feels smooth and natural to me. My upper pressure is lower than yours though.

YOU SAID: "Okay, I experimented for you last night. I had machine pressure set to Autoset 8-11 with EPR at 3 full-time. There is definitely a very pronounced difference in inhale/exhale pressure. I can hear it with each breath as well."

Was this with the S8 or the S9 ?

I used the S9 Autoset last night, pressure set to 8-11 with EPR at 3 full-time.

YOU SAID: "Last night it felt like it was pushing air into me, especially at the end of inhales, which is the same sensation I had with the S8. It feels like it's expanding my lungs. In contrast, when I have EPR set to off, I don't feel the air movement at all"

EPR is not supposed to modify inspirations. If only changes the expirations. Puzzling.

I do not like EPR. It doesn't feel like natural breathing to me. It feels like the air is forced in at the end of inhale, right before it decreases the pressure for exhale. But it may be the inhale/exhale pressure transition that I'm sensing. I don't think that the machine's EPR inhale/exhale timing works well with my breathing pattern; it's like I'm ready to exhale, but the machine is still giving full pressure. I think that's why the air feels forced at the end of inhale to me. Both the S8 and S9 machine's EPR felt that way to me. For that reason, I feel like I breathe better with EPR off.

My machine makes no sound changes with inspiration or expiration, with or without EPR on and at any 1-3 level.

I could definitely hear a difference in inhale/exhale with EPR on with my S9 machine.

TODAY: I'll replace the condom with a column of water in a tube, or a proper meter. Given what I observed with the condom inflation and deflation, I'll bet my EPR section is defective.

How are you testing the EPR pressure changes? It is my understanding that EPR responds to your breathing, so you'd have to be wearing the mask to test it. Is your pressure-measuring device in the circuit between the machine and mask (either between machine and hose or hose and mask)?

TODAY: I'll replace the condom with a column of water in a tube, or a proper meter. Given what I observed with the condom inflation and deflation, I'll bet my EPR section is defective.

How are you testing the EPR pressure changes? It is my understanding that EPR responds to your breathing, so you'd have to be wearing the mask to test it. Is your pressure-measuring device in the circuit between the machine and mask (either between machine and hose or hose and mask)?[/quote]


Absolutely. It's an in-line tester with my mask at the end. First I used a condom, and tonight a water column.

Physician,

Perhaps you might try renting a PR S1 for a week or two and see if you find that more comfortable. It seems to go immediately to full pressure and the EPR (Aflex) is clearly noticeable (though very comfortable). I can even see my hose move ever so slightly with the pressure relief.

IMHO, the S9 has some bells and whistles that make it preferable to the PR S1, but the PR S1 is a very good machine and might be more comfortable for you. With a rental you can give it a "test drive" and see how you like it.

Physician, as I posted in another thread, EPR works so well on my S9 that I did not think it was working at all until I tried using a Mirage Quattro mask. When I inhaled the seal would swell up like a ballon. When I exhaled, the swelling would go back down. It was so annoying I finally turned EPR off with it. I gave-up on the Quattro mask because my wife and the Detailed Data from the ResScan software indicate that I snore in the mask.

Right now I am back to my Swift FX mask. My titrated pressure was 6. My S9 is currently set to CPAP at 8. If I understand this correctly, EPR at 2 gives me my titrated pressure on exhale, and a slightly higher pressure on inhale. What is more important though, is my AHI is finally staying under 5 (often as low as 1.5) with these settings.

I do not use the ramp feature. And I don't notice the seconds it takes for the machine to get up to pressure because I am usually busy wrapping tape around my head while it is doing that.

I have my S9 set at auto, pressure range 7 to 15 and EPR at 3 full time. I do feel a big difference with EPR on. I can feel the pressure reduction and it definitely made it much easier when exhale.

I am surprised to hear so many of you can't feel the difference with or without EPR. Perhaps there is a batch of S9s that has glitches in EPR algorithm. Mine EPR is very noticeable even at setting of 1 or 2. I would definitely ask your DEM to check it out.

Janknitz wrote:Physician,

Perhaps you might try renting a PR S1 for a week or two and see if you find that more comfortable. It seems to go immediately to full pressure and the EPR (Aflex) is clearly noticeable (though very comfortable). I can even see my hose move ever so slightly with the pressure relief.

IMHO, the S9 has some bells and whistles that make it preferable to the PR S1, but the PR S1 is a very good machine and might be more comfortable for you. With a rental you can give it a "test drive" and see how you like it.

As you'll read in another thread, I did sample the PR S1 and was bothered by it taking FOUR breaths to auto-start whereas the ResMed started within (and not after) the first breath.

SEE HERE: viewtopic/t53451/Comparison--S9-AutoSet ... arPro.html


Your thoughts ?

frh wrote:My S9 is currently set to CPAP at 8. If I understand this correctly, EPR at 2 gives me my titrated pressure on exhale, and a slightly higher pressure on inhale.

EPR (Exhalation Pressure Relief) gives you your regular pressure on inhale and drops it on exhale by the EPR number. So, if your pressure is set to 8 and you have EPR at 2, you're inhaling at 8 and exhaling at 6. The minimum pressure the machine is capable of is 4. If your set pressure was 6 and you had EPR at 3, then inhale would be at 6 and exhale at 4, since it can't drop below that.

tonytexas wrote:I am surprised to hear so many of you can't feel the difference with or without EPR. Perhaps there is a batch of S9s that has glitches in EPR algorithm. Mine EPR is very noticeable even at setting of 1 or 2. I would definitely ask your DEM to check it out.

Tony, as far as I know, Physician is the only person that has mentioned that he can't feel EPR on his S9 machine at all. Especially if he's using the Activa LT that's listed in his profile, he should notice EPR because that mask does have a tendency to "bellow". I was wearing nasal pillows when I tested EPR at 3, and it was very noticeable! I do think there is something wrong with his machine, especially since he has used the S8 and knows how it should feel. I definitely feel a pronounced difference in inhale/exhale pressure when EPR is used on the S9, as I did on the S8.

Physician wrote:Absolutely. It's an in-line tester with my mask at the end. First I used a condom, and tonight a water column.

Were you able to reach any conclusions from your test last night?

DreamOn wrote:

frh wrote:My S9 is currently set to CPAP at 8. If I understand this correctly, EPR at 2 gives me my titrated pressure on exhale, and a slightly higher pressure on inhale.

EPR (Exhalation Pressure Relief) gives you your regular pressure on inhale and drops it on exhale by the EPR number. So, if your pressure is set to 8 and you have EPR at 2, you're inhaling at 8 and exhaling at 6. The minimum pressure the machine is capable of is 4. If your set pressure was 6 and you had EPR at 3, then inhale would be at 6 and exhale at 4, since it can't drop below that.

DreamOn, thanks for confirming that. I set my S9 to my titrated pressure of 6 with EPR set at 3 for about 2 weeks prior to my recent visit with my new sleep doc. After reviewing my ResScan reports, he told me to set the machine to 10. I started having centrals so I split the difference. I turned the pressure to 8 and the EPR to 2. My AHI has been staying under 5 at those settings. (Last night my AHI was 2.2.)

frh wrote:I turned the pressure to 8 and the EPR to 2. My AHI has been staying under 5 at those settings. (Last night my AHI was 2.2.)

I've been using xPAP for 9 months now. I was at set pressure of 8 myself for many months, with no EPR. I did very well at 8 on the S9 machine (AHI usually around 0.5, with no obstructive apneas and a few centrals). I even had some zero-AHI nights!

I just started using Autoset mode a week ago. I'm trying various upper/lower pressure settings. Results so far are confusing, but I suspect that I will eventually go back to CPAP mode.

As you'll read in another thread, I did sample the PR S1 and was bothered by it taking FOUR breaths to auto-start whereas the ResMed started within (and not after) the first breath.

Try deeper breaths. My PR S1 starts in 1 or 2 breaths. I do find it a bit annoying because the way it synchs I'm wanting to exhale when it starts blowing, so I have to either exhale against that pressure or make a long exhale between the beep and the moment it turns on. But that is a few seconds out of my night, no biggie.