FOT Algorithm

Is the S9 FOT algorithm supposed to work with a fixed pressure or only when a pressure range is in use? I used to notice it when I would stop breathing, as I changed positions, as I fell asleep (using a pressure range). However, once I switched to a fixed pressure, I didn't notice it anymore.

FOT is used to help the machine decide if the airway is open or closed and it works in both fixed and apap (auto adjusting pressure) mode.

Perhaps in fixed mode it just doesn't need any help in figuring out what is going on in terms of airway status.

Thanks Pugsy...if I hold my breath long enough, it should trigger the FOT right? If it doesn't start while holding breath is there a problem with my CPAP? Any other way to test or determine if working?

In theory I suppose if you hold your breath it should/would trigger FOT but FOT is only used when the machine needs help in deciding what to call an apnea so it wouldn't be impossible for the machine to decide without FOT what to call it. Awake "events" trying to fool the machine into doing something isn't all that reliable way to test things.
I have seen my machine be fooled by my holding my breath and it calls it an OA and not a central.
Awake breathing will just sometimes confuse the machine.
I have never been able to sense FOT either.

I think I now understand more about something I've be curious about. I have often noted a pattern in the mask pressure and flow rate traces in SH with my AS10. In other wave forms in other situations, I would call it a "ringing" in the waveform. This would occur in the time approaching the point of a CA marker. I looked at a ResMed whitepaper and it seems to illustrate this pattern well. See: https://www.resmed.de/fileadmin/templat ... -paper.pdf
Am I interpreting this correctly? I am not certain in what way, if any, the implementation has changed in the AS10 compared to the S9 referenced in the paper; looking at the traces I doubt the pulsing frequency and range of amplitudes exhibited would rise to the point of being easily felt by the user. It just seems altogether too rapid and too shallow to be felt well - but, I could be wrong.

JimW159 wrote:I think I now understand more about something I've be curious about. I have often noted a pattern in the mask pressure and flow rate traces in SH with my AS10. In other wave forms in other situations, I would call it a "ringing" in the waveform. This would occur in the time approaching the point of a CA marker. I looked at a ResMed whitepaper and it seems to illustrate this pattern well. See: https://www.resmed.de/fileadmin/templat ... -paper.pdf
Am I interpreting this correctly? I am not certain in what way, if any, the implementation has changed in the AS10 compared to the S9 referenced in the paper; looking at the traces I doubt the pulsing frequency and range of amplitudes exhibited would rise to the point of being easily felt by the user. It just seems altogether too rapid and too shallow to be felt well - but, I could be wrong.

watch this, air10 works the same as the s9. https://www.youtube.com/watch?v=4GW97Xk06N8

fwiw, I can feel the FOT. it also makes my mask tube wiggle

palerider wrote: watch this, air10 works the same as the s9. https://www.youtube.com/watch?v=4GW97Xk06N8
fwiw, I can feel the FOT. it also makes my mask tube wiggle

Good video, thanks
To your last point: I suspect you are just a more sensitive human being than I.

Newquestion wrote:Thanks Pugsy...if I hold my breath long enough, it should trigger the FOT right? If it doesn't start while holding breath is there a problem with my CPAP? Any other way to test or determine if working?

If you just want to play with your machine, maybe you should trade it for a slinky, don't trade it for a Rubins cube, (SP) you couldn't handle one! Jim

Goofproof wrote:

Newquestion wrote:Thanks Pugsy...if I hold my breath long enough, it should trigger the FOT right? If it doesn't start while holding breath is there a problem with my CPAP? Any other way to test or determine if working?

If you just want to play with your machine, maybe you should trade it for a slinky, don't trade it for a Rubins cube, (SP) you couldn't handle one! Jim

Rubik's cube. I only solved it once.
I felt the FOT working on a couple of occasions. The pulse is fast like your anti lock brake system on your car when you break hard.