The was the system works is that before you start to inhale the inside of the mask will be at therapy pressure. As you inhale you are lowering the pressure in the mask, so the system speeds up the blower unit to keep the pressure up. At the end of the inhale the blower will slow down to keep from over pressurizing the mask. The system will only change the blower speed (pulsing) if your inhale changes (or you are having leaks) .
The blower speed can change quite quickly and the pressure should remain pretty stable. It is electronics and can only do what it is designed to do.
We on the other hand react to all kinds of things. Have you ever had anyone blow air in your face and reacted to it? None of us are used to air blowing in our face while trying to relax and just breathe. It is not "normal", we can get used to it though. Every time we change our inhale the machine will detect it and react to it. The machine is trying to detect when we stop inhaling and if you trigger the machine into thinking that you have stopped it will adjust. If you then continue your inhale the machine will react to that also and faster then you can change your breathing. This can go back and forth changing pressure up and down causing you react to it, over and over.
Is it all in your head, well not really, it is happening. If the machines break, they usually just stop or get stuck wide open. Try putting the mask on with pressure and do some slow breathing. concentrate on controlling the rate of your breathing, slow and steady and see if the machine lets you alone and just follows you.
Some machines have what they call a "flex" function. Maybe yours is turned on or adjusted in some way that you are noticing it. With that function, the machine senses your exhale and drops the pressure so you aren't exhaling against it. Then, they sense your inhale and jump back up to pressure. There are ways to turn this on and off, and ways to adjust the timing and pressure changes. This might be what you are feeling. On mine, I turn that function off and leave the constant pressure on the whole time.
And yes, they do make adjustments to maintain that constant pressure, too. With a full-face mask, there is a lot more air volume inside vs the nasal pillows you started with. The system might be making a lot of extra adjustments because of that. (I use the Swift FX myself).
ResMed machines have EPR. It's a drop in pressure upon exhale. During inhale, pressure should be constant and not "pulsed."
Most people do better with a short ramp time; or with ramp off.
If there's a pulsing during inhale, make sure the entrainment valve in the Quattro elbow is acting normally (closed under positive pressure.)
And, make sure it's not water droplets shooting along the tube. Water may indicate the tank is too full; or the the humidity setting is too high.
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all good points justMongo
The machine should not feel like it is changing pressure or fluttering as you inhale. That description sounds like a defect. Make sure that the air-flow is not obstructed by water in the hose or humidifier water that is too high, or an improperly installed air filter. If you do feel a pulsing airflow have your supplier check the machine.
07-05-2016, 11:20 AM
(This post was last modified: 07-05-2016, 11:28 AM by theone.)
Not sure I mentioned this in my previous posts the reason I have switched from nasal pillows mask (Swift FX) to current one because of this problem. Checked all carefully including distilled water lever in the humidifier. All seems right. I agree with previous post,the machine my not work as it should.. Supposedly is brand new unit...
Hopefully I will be able to attach screen shot,and local guru interpret it so adjustment can be made.. I need get some sleep!