90 day update

[Sleeprider]

Good job on the graph.  The timeline begins in a hypopnea, that then has some normal looking breaths and trails off into what appears to be CA where we can see the FOT oscillation. What we can see from this snap shot is that your respiration is normal with longer expiration than inspiration. The inhales are everythin from where the line rises above zero, until it drops back to zero. Exhale is from the moment it drops below zero, and includes the zero flow along the horizontal zero flow line until a distinct inhale occurs again.  We can see some irregularities in the flow line, and this is throwing off the machine.

Notice at 03:37:55 how the mask pressure becomes jagged?  In fact, for every breath here, the mask pressure does not really settle in at EPAP bit wavers.   What ever is going on with that ragged exhale, it really confuses the machine.   With all the CA evens I see, and the rather poor tracking of the machine for IPAP/EPAP, I would just turn off EPR, but if you find it comfortable it's not hurting anything.  The point is, you don't really have an unusual I:E ratio, the machine just takes the first increase after exhale and labels that as start of inspiration.

[Sleeprider]

Since we got into this discussion, let me add, there is nothing you can do about it. The machine gets confused because you have such a long zero-flow at the end of expiration. That may not be typical for you since it looks like hypopnea.  Here is my chart and as you can see, it is much easier for the machine to 'know' when inhale begins and ends.

[JohnnyGobbs]

Ok. Thx sleeprider for all your help! I guess I'll just ditch the epr then as it can't help.

[Sleeprider]

I can't say if it helps or not, but it is not able to work as designed with the irregular breathing pattern in that brief screenshot. It might be different at other times of the night. I think it's fine to experiment with different EPR settings including off, but if you try something, stick with it a couple days so you can establish a baseline

[Shin Ryoku]

An interesting view is to zoom in to less than 2-minutes so you can see a high level of detail in the flow rate (be sure to right click on the right axis and add a dotted line for zero flow). On Resmed machines, include the mask pressure graph.  What we normally see in these inverse I:E ratios is an abrupt exhale followed by a blip then a period of null flow before the next inhale starts.  Normal respiration the exhale ends gradually and ends up near zero flow before inspiration.  My theory is that most of these individuals that record inverse I:E actually have normal I:E, it's the machine that gets messed up by the abrupt end to exhale and sometimes a brief pressure drop that it records as the start of inhale.  So this not only messes up the reported I:E ratio, but it means the machine is actually out of sync with that person by starting the inhale (IPAP) before exhale has ended.  

I noticed that visually speaking, my I:E is less than 1 with my ResMed devices (regardless of EPR) as well as my PR devices when C-Flex is off.  But with C-Flex on, I get an I:E that visually appears to be greater than 1.

Here are some examples.  This is my PR DreamStation with C-Flex off:



And this is with C-Flex 3:




Those examples are representative of a consistent finding in my flow rates with C-Flex off and on. I'm not cherry picking here.

It was suggested to me on another board that the bumps I'm seeing in early inspiration with C-Flex on are artifactual and that the true I:E is less than 1 regardless of C-Flex setting.  I think that is along the same lines as what you are suggesting.  But whatever it is, in my case SleepyHead isn't showing it as null flow being counted as inspiration.  Right or wrong, it is depicting that segment as positive flow.

[Sleeprider]

I agree that the influence of CFlex is causing the error. The tapering of flow during exhale, immediately prior to inspiration, is a classic feature of respiration and pretty much shows that the zero-line is improperly placed by the machine, causing a shortened expiratory time. I have no idea why this would happen, but more often than not, the error in the I:E ratio is with the machine.