There is a ventilator concept(with pressure booster double acting) that's fully mechanical and very simple that can be plugged into an air supply or water supply to power the ventilator. It sould easily be made and used anywhere in the world at home, ICUs and ambulances. The ventilator could operate without any power source at all. It can be powered by water (even by any tape) You can easily add adjusting stroke length & volume of breath, cadence, ratio of inhale/exhale, connecting many ventilators to one system etc.. Let me know and feel free to develop the idea further !