As countries affected by the coronavirus pandemic expect to run out of ventilators and other equipment, makers are desperately trying to fill the gap with proposals for open-source, do-it-yourself devices.

Most cases of COVID-19—the disease caused by the novel coronavirus—do not require hospitalization. But for people hospitalized with severe infections, coronavirus damages their lungs and makes it hard to breathe in and circulate the amount of oxygen that their bodies need. Ventilators, machines that provide the lungs with oxygen, are proving to be key to treating these people, who seem to comprise around 10 percent of cases.

Governments are already preparing for what a shortage of ventilators could do to their health care systems.

In a call to U.S. governors on Monday that was shared with The New York Times, President Donald Trump told states not to rely fully on the federal government for equipment. "Respirators, ventilators, all of the equipment—try getting it yourselves," he said, according to The Times. "We will be backing you, but try getting it yourselves. Point of sales, much better, much more direct if you can get it yourself."