This MIT project is developing open source plans for a ventilator in response to the Coronavirus panedemic. A lack of ventilators within the US and globally could result in the deaths of hundreds of thousands of people who need them to stay alive during the more severe phases of the disease.
Almost every bed in a hospital has a manual resuscitator (Ambu-Bag) nearby, available in the event of a rapid response or code where healthcare workers maintain oxygenation by squeezing the bag. Automating this appears to be the simplest strategy that satisfies the need for low-cost mechanical ventilation, with the ability to be rapidly manufactured in large quantities. However, doing this safely is not trivial.