how is inspiratory and exhalation time measured

[car54]

Just curious how inspiratory and exhalation timse measured. 
Here are 2 charts of close ups of which you can analize.
This is what my normal breathing looks like.

   

   

[2SleepBetta]

Others will likely offer help, regrettably I cannot, given your consistent FR pattern I've not seen before. 

This link to a Resmed patent shows how it's done by their algorithm in general https: https://patentimages.storage.googleapis....2088A1.pdf .

Out of mere curiosity, I'd add to the 1-minute view vertical zooms of inspiration and exhalation curves and then slowly drag the cursor along breath by breath to see how well starts and ends of breaths correlate with times and flows, with an eye also noting the curve value read outs at the upper left corner of each graph. 

I've not seen those interruptions, short stops in exhalation before resuming exhalation and reaching peak exhalation flow. Only one instance at about 1:07:42 had a short inspiration, not just a brief stop. In paradoxical breathing I've done myself a bit and seen, there are a couple or more apparent cycles of tiny "breaths", inflow and outflow cycles, within each whole breath cycle. Those mini breaths are absent in your flow rate curve, with the one possible exception I noted.  

In paradoxical breathing, I believe our devices can have difficulty in deciding where the zero axis is, which impacts the inspiration and expiration time presentations.

The last couple breaths of the two-minute view look typical. Are those exceptional for you?

[Sleeprider]

Very simply inspiration time and expiration time are technically measured from the time inspiratory flow rises above zero to when expiratory flow is sensed, represented by less than zero flow (impossible, but that how it looks on the chart). The zero line crossover is where you are inhaling or exhaling and the horizontal space between those crossovers is time. You have an interesting permutation, in this portion of your sleep. Your end of inspiration reaches the zero flow, and slightly rebounds before normal expiration begins. This could be an expiratory flow limitation, loose tissue or phlegm or even a swallow or simply a breath-hold. At the moment this occurs your lungs are full and expiration has not really begun. This is not palatal prolapse. Try taking in a breath and just as exhale starts, briefly hold then release the air. That's what we're looking at. This may be a small portion of your sleep related to sleep stage. The Resmed devices do a pretty good job of approximating a respiratory flow chart, but it's not truly diagnostic due to the distance and air space between the flow sensor and patient. There is a wiki on the I:E ratio you can look for.

[car54]

Sleeprider,
So everything above zero is inhale and below zero is exhale even though on the graph it shows a rising line below zero and a lowering line above zero. Just curios, so it is not from the high point.

On the 1st charts that I posted, I had breathing like that, any where from 10 minutes to 2 hours about 4 or5 separate times

Just trying to get facts together. I meet with my new pulmonologist at the end of the month. I am trying to get a new aircurve through medicare. I was able to get my old pulmonologistto write a prescription for a aircurve but the DME said that I was well treated and that I do not need it. So they refused it and my doctor left it at that. Since then I bought a used aircurve which is getting old. I met with the new pulmonologist's PA a few months ago and explained it to him. He inferred that it might be a challenge and I may have to have a "real" sleep test done. My previous ones were done at home. Can a proper sleep study determine if an aircurve would be better?

Just for the heck of it here are some graphs of an airsense with zero EPR.

   
   
   

[car54]

Here is a chart of last night. I went through the whole night and I had about 400 minutes of this. 
Is there something that I should be asking my doctor?

   

[Sleeprider]

Yes to your question if everything above the zero line is inspiration and below is expiration. Even though it is tempting to regard everything following the peak inspiration as exhale, it is actually a natural slowing of airflow as the lungs reach capacity and inspiratory effort slows. Similarly, as exhale flow increases, the flow rate line falls farther below zero, but again flow rate slows and may become zero before inspiration begins again.

When looking at these flow graphs, you should start using mask pressure rather than just the pressure chart. It will generally show a wave-form that is the mirror of your respiratory flow. In fact the best respiratory charts are already preset for you by going to the menu/view/Reset Graphs and select Advanced. Your flow rate graph shows normal inspiration and a slower, sometimes irregular exhale that begins, pauses and continues. I see a lot of individual variations in respiratory patterns, and have seen this in other member's graphs. I have no clue why it occurs or if it is even a problem, but am not aware of a means to change it through settings on the device. If you're concerned ask your doctor, but my advise has always been to not focus too closely on the detailed flow rate graphs. They are inevitably full of anomalous bumps, variations and pauses. Many members even have cardiogenic oscillations from their heartbeat that shows up in the expiratory flow rate. https://www.apneaboard.com/wiki/index.ph...cillations

[car54]

Thanks Sleeprider,
I usually go months with out looking at the charts. I have been looking lately because of a doctors appointment.