How do we know that they <are> arousal events?
But an event of shorter duration may not be an arousal. I do not know this but am just speculating.
True enough. It may not be. With a UF default of 8 seconds it's close enough to the standard 10 and if one is not feeling rested in the AM with a very low AHI, UF 1s or 2s might help explain why. It's a place to look to try and find a reason why.
Following up on your point it would be interesting if one of our members who is seeing a sleep doctor soon could ask the question of whether an 8 second "event" is enough to constitute an "arousal".
Sorry, but the term arousal and the term apnea event are so different they cannot be describing the same thing. There are many apneas that resolve without arousal per se. There are many arousals that are not scored as apnea or even hypopnea. Case in point, RERA or respiratory effort related arousals are detected by some machines, and those wave forms do not resemble the hypopnea or apnea events. There are arousals that are not connected with any apnea, such as periodic leg or arm movement, or from being startled by noises inside or outside. There are apnea that get resolved by central nervous system feedback, without arousal; there are apnea caused by mechanically overventilating which may not lead to arousals. My natural arousals throughout the night are not the product of apnea, hypopnea, or mini- or micro- UFish partial unscored apneas.
I applaud your use of the experimental SH parameters of UF1 and UF2 to try to correlate the feeling you get when the frequency of these parameters are higher versus lower. But, there may or may not be a direct correlation. Many suffering from sleep disorders do not even exhibit apnea.
soap box has been removed, and my rant is now over -
Dedicated to QALity sleep.
You'll note I am listed as an Advisory Member. I am honored to be listed as such. See the fine print - Advisory Members as a group provide advice and suggestions to Apnea Board administrators and staff concerning Apnea Board operation and administrative policies. Membership in the Advisory Member group should not be understood as in any way implying medical expertise or qualification for advising Sleep Apnea patients concerning their treatment.
My AHI has always been below 1.
FWIW, I have tweaked UF1 and UF2 parameters and recomputed these indices for values of 5-8 seconds and 10% to 80% reduction in airflow. I found no correlation with how I felt in the morning. So these may be of dubious value to diagnose sleep issues and sleep related arousals.
Started APAP 4-20, Closed range to 7.5-14, then straight 8.0 w/ Aflex 3
RDI always below 1. But sleep much much better at straight pressure.
Started on F10, Tried Quattro Air successfully. Finally settled on P10.
I find that when I am really examining the data for some purpose other than a routine check, that zooming in on the flow rate and scanning through the whole night is best. Rather than trusting an algorithm I can actually see all the nuances of my breathing. I don't have to wonder what the algorithm settings might have missed. In addition to seeing every apnea/hipopnea no matter the length, I can also assess areas of rough or distorted breathing.
When I was first setting up my APAP this allowed me to understand that I needed a little more pressure than the auto wanted to settle at. I had good AHI but was not getting rested. So I nudged the run pressure up with my min EPAP setting.
if you can't decide then you don't have enough data.