All of the data you are talking about

It is a pressure relief when the machine senses that you are exhaling, it drops the pressure. That's what your saying "rhythm" made me think of. Hopefully Pugsy can give you more detail on the settings as I am not familiar with your machine. Mine has 3, 2, 1 or off settings. I think it also has a fast, medium or slow which is only available in either cpap or auto, I can't remember which. I tried different settings before I finally turned it off.

The Flex setting on the PR S1 machine is exhale relief.
EPR is exhale relief on the ResMed machines.
While they are both forms of exhale relief they do go about it in a different manner. ResMed EPR simply reduces the pressure during exhale phase of breathing by the cm amount of the setting chosen and a person can also change the rhythm a bit (fast, slow...)

Hard to describe Flex exhale relief. It is a much smaller drop in pressure and more of a rhythm change. Example shown here. I found that the setting of 3 on the Flex part, tried to make me feel like I was breathing too fast to keep up. I did better at setting of 1. This is strictly a comfort feature and you are free to change settings and even turn it off to see which feels better for you. This might explain some of the "stifled" feeling you are experiencing. Perhaps the "rhythm" is a bit off. Of all the complaints I see it seems like setting of 3 is "too fast" and people like the lower settings better, or simply turn it off altogether.
http://cflex.respironics.com/

This sounds like it could definately be one of my problems. Can you tell me where this adjustment is made? I am assuming this will only make a difference when I first put the mask on and turn it on is that correct. Or is an adjustment to this setting something that could actually help this machine work better for me all night?

THanks for all the help!

The Flex works all night.

sleepyleaf wrote:This sounds like it could definately be one of my problems. Can you tell me where this adjustment is made? I am assuming this will only make a difference when I first put the mask on and turn it on is that correct. Or is an adjustment to this setting something that could actually help this machine work better for me all night?

Like Slinky says, Flex setting continues all night.
Ramp would be the only one that could be used when first putting mask on to help with initial pressure adaptation. I never used it. I like the full air myself. It is a personal choice thing.

To change CFlex settings you can see it on the LED screen and usually can just turn to it and punch the round button to access settings. If by chance DME has you locked out, you can go to the clinician menu and change it from there.

http://www.apneaboard.com/PR-System-One ... -Setup.htm

If you don't have a copy of the clinician manual, probably would be good idea to get one. At this link below scroll down till you see the instructions for requesting the manual in pdf form. It has pictures and explanations for all the settings and how to get to them. Makes things much easier. Plus nice to know what all the features are on your machine.
http://www.apneaboard.com/CPAP%20Adjustment.htm