High altitude simulation CPAP

[DH12]

This might be a weird question, but are there any CPAP machines that can simulate high altitudes by delivering air with a lower oxygen content?

Kind of like what the tents do that you sleep in to simulate higher altitudes.

[Sleep2Snore]

Not that I know of, that would mean taking out some oxygen and that is not a thing they would make a machine for. A cpap machine is designed to supply air at a set or varied pressure/flow.