Mechanical Ventilator Milano (MVM) is designed by a team of particle physicists and engineers from nine countries in response to COVID-19 Pandemic and ventilator shortage
Cost Containment: the total cost of the components is in the hundred Euros.
How to design: https://arxiv.org/pdf/2003.10405.pdf
How it works: https://mvm.care/design-en/
FermiLab news: link
The end result is an open-source ventilator with off-the-shelf parts that the MVM team hopes will close the gap between supply and demand on a short timescale. The hardware and software designs will be made publicly accessible, so in principle, anyone in the world could make their own version. Link