New to S9 – my first FOT experience.

avi123 wrote:On a second thought, since FOT occur only during apnea, either open or closed airway, you should NOT feel it. Because if you are aware of it then it means that you are awake. And if you're awake then you overcome the apnea by respiring regularly and the FOT stops. If you feel the FOT it might be an indication that your machine malfunctions.

The machines often think you're having an apnea while awake, so they will apply FOT despite you being awake or half asleep.

I often get "real" apneas when I'm somewhere between wake and sleep and am conscious enough to notice the difficulty breathing and remember it. I could probably feel FOT at that time as well, but I don't really feel FOT even if I fool the machine into doing it while completely awake.

The 1 cm H2O amplitude pulses are able to be perceived
by a patient if they are awake but are not large enough to
arouse them from sleep

Perhaps the Apnea causes the arousal and then the FOT is detected. Or during the N1 stage...

Does FOT work in CPAP mode aswell as APAP mode?
Obviously in CPAP there is not need to determine the apnea type to judge whether a pressure increase is necessary.
But it would be usefull to see a central recorded in your data even when using CPAP.

~UB

UB, as I understand it, in S9 machines the FOT is applied both in CPAP s and APAPs. In CPAPs it does not effect the pressure but it is used to classify between closed and open airway for flagging. In the APAP it also decides if to raise the pressure or not.

p.s. what about ResScan 4.1?

BasementDwellingGeek wrote:

The 1 cm H2O amplitude pulses are able to be perceived
by a patient if they are awake but are not large enough to
arouse them from sleep

Perhaps the Apnea causes the arousal and then the FOT is detected. Or during the N1 stage...

You want to tell me that you can pecieve a 4 Hz tone in your S9:


https://www.youtube.com/watch?v=BdQbQa- ... re=related

avi123 wrote:You want to tell me that you can pecieve a 4 HZ tone in your S9

I suppose you could mask up, turn the machine on, hold your breath and see if you can feel it. I have not overtly tried, myself, but I think I felt it but once one time long ago.

You want to tell me that you can pecieve a 4 Hz tone in your S9:


https://www.youtube.com/watch?v=BdQbQa-r ... re=related

Based on the samples in the link I would say I was sensing something about .5Hz. I noted the approximate times, then the next morning scanned the flow waves for anything unusual. I found the FOTs. I have no recollection of experiencing any last night, despite scoring two OAs and a dozen or more FOTs visible in the flow data.