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+--- Thread: Why aren't the slopes smooth? (/Thread-Why-aren-t-the-slopes-smooth)
Why aren't the slopes smooth? - SleepFoo - 07-07-2022
Does the slope for my inhale look normal? It looks like there's a hesitation on the inhale as if the machine is pausing, thinking I should be done inhaling, but then realizes I'm still inhaling and continues on.
If anyone could explain what that is and if it's normal or can be adjusted, I'd appreciate it.
Thanks in advance.
RE: Why aren't the slopes smooth? - kappa - 07-08-2022
That looks like a regular pause between breaths (exhale finished, inhale not yet started). Nothing to be concerned about. If you add the "Zero" dotted line (right click on the "Flow Rate" heading) it will be clearer.
RE: Why aren't the slopes smooth? - SleepFoo - 07-08-2022
I zoomed in a little more and pointed to the plateau. That's not exhaling, is it? Is that a short exhale and then an inhale?
RE: Why aren't the slopes smooth? - SleepFoo - 07-08-2022
This might show it better. I see a longer plateau here.
RE: Why aren't the slopes smooth? - SleepFoo - 07-08-2022
This one is a smooth slope. I see more of these some nights than others. Some nights, it seems like its all just the previous version.
RE: Why aren't the slopes smooth? - Sleeprider - 07-08-2022
All of these plateaus show that as exhale completes, you have a short period of zero flow before inspiration begins. This is normal, and can be very pronounced in some people. If that zero-flow continues for 10 seconds, it is an apnea, and you will usually see the machines pressure pulses (FOT) superimposed on the respiration flow rate. Your results are very good, but if you want to have the machine trigger IPAP with less inspiratory flow to trigger it, then switching the Trigger Sensitivity to "high" can sometimes reduce this period of null flow. If you do this, your job is not to study the flow curve, but to decide if it feels better and more natural for you. If yes, keep the change; if no, return to previous setting.
RE: Why aren't the slopes smooth? - GuyScharf - 07-08-2022
Between your inhalation and exhalation, there is a slight pause where you are neither breathing in nor breathing out. However, your heart is still beating and for some people this causes the little flow bumps you see. There are called cardio ballistic effects. See https://www.thoracic.org/professionals/clinical-resources/sleep/sleep-fragments/artifact-in-the-airflow-channel.php (click on Answer) for one discussion of this behavior.
RE: Why aren't the slopes smooth? - SleepFoo - 07-08-2022
(07-08-2022, 01:54 AM)kappa Wrote: That looks like a regular pause between breaths (exhale finished, inhale not yet started). Nothing to be concerned about. If you add the "Zero" dotted line (right click on the "Flow Rate" heading) it will be clearer.
Thanks for the tip.
(07-08-2022, 07:39 AM)Sleeprider Wrote: All of these plateaus show that as exhale completes, you have a short period of zero flow before inspiration begins. This is normal, and can be very pronounced in some people. If that zero-flow continues for 10 seconds, it is an apnea, and you will usually see the machines pressure pulses (FOT) superimposed on the respiration flow rate. Your results are very good, but if you want to have the machine trigger IPAP with less inspiratory flow to trigger it, then switching the Trigger Sensitivity to "high" can sometimes reduce this period of null flow. If you do this, your job is not to study the flow curve, but to decide if it feels better and more natural for you. If yes, keep the change; if no, return to previous setting.
I will definitely give the sensitivity trigger an attempt and feel it out.
(07-08-2022, 07:11 PM)GuyScharf Wrote: Between your inhalation and exhalation, there is a slight pause where you are neither breathing in nor breathing out. However, your heart is still beating and for some people this causes the little flow bumps you see. There are called cardio ballistic effects. See https://www.thoracic.org/professionals/clinical-resources/sleep/sleep-fragments/artifact-in-the-airflow-channel.php (click on Answer) for one discussion of this behavior.
That makes a lot of sense. Thanks for the added information.