There are a lot of dimensions to this: The Pandemic Ventilator Project <a href="https://panvent.blogspot.com/" rel="nofollow">https://panvent.blogspot.com/</a> is taking this on. If you happen to have $15,000.00 lying around, buying one appears to be an option, although I bet the sell out quickly ... Building an iron lung out of wood, from Popular Mechanics magazine, Jan 1952, is also described here: <a href="https://books.google.com/books?id=tNwDAAAAMBAJ&pg=PA262&source=gbs_toc_r&cad=2#v=onepage&q&f=false" rel="nofollow">https://books.google.com/books?id=tNwDAAAAMBAJ&pg=PA262&sour...</a>. Presumably a simple CPAP machine would help, but it 'aerosolizes' the virus, and makes it likely that any caregiver would be much more likely to get sick. Also, a CPAP machine doesn't give as much help as a real medical respirator as far as I can tell.