[Alkim]

Well it has been a few years from when I took my Thermo course, and yes the proper way to do this is to compute the work required for compression. I'd invite this thread to do a proper job with the math. And if you've used a CPAP as I have you know that it actually assists your chest in moving, which is even a more considerable mass--there's a lot of energy being used in my CPAP device.

[PuffinBlue]

Does the CPAP need to do that? Assist in moving your chest I mean? It seemed from the video that they are targeting the collapse of the soft tissue in the throat. Perhaps the energy required to do that would have the side effect of assisting to raise the chest?

I've never used on of these devices so I'm curious about it.

How do you exhale? If it's forcing air in at a decent pressure then does it detect an exhale or are you expected to just push on through?

It seemed like from the video they airing would add pressure to the inhalation and switch off for the exhalation, or at least that's what I'd try and do, but then I don't know much about these things!

[jwynia]

My ResMed S9 machine detects exhalation (configurable levels) and backs off of the pressure. The mask that I wear (covers mouth and nose) has small holes that vent both exhalation and the pressurized air. The air flow out of those holes is relatively stable during both inhale and exhale, with the machine adjusting pressure to keep fresh air flowing through the mask and maintaining the pressure.