It started with a fanciful email from one self-described science geek to another. “Hey, we should make a ventilator,” Dr. Chris Zahner, a University of Texas pathologist and former NASA engineer, wrote to Aisen Caro Chacin, an artist and medical device designer, after he learned about Italian hospitals struggling to treat the crush of coronavirus patients gasping for air. Two and a half days later, Dr. Zahner and Dr. Chacin were testing out their prototype at the university’s medical fabrication lab in Galveston: a simple air pump that uses ordinary blood pressure cuffs, car valves sold by auto parts stores and items found in most hospital supply closets. They are awaiting approval from the university’s medical review board before trying it out on patients. “We hope doctors in the U.S. never have to use them, but in an emergency they should do the trick,” Dr. Chacin said. Spurred to action by a shortage of lifesaving medical supplies and mechanical breathing machines, engineers, software designers, factory owners and self-taught sewers around the world have been racing to devise products they hope can help keep critically ill coronavirus patients alive and health care workers safe from infection. The vast majority of products have not received the necessary blessing from the Food and Drug Administration, but in the face of the pandemic the agency said it was willing to be flexible in evaluating newly created devices and gear. It took just two weeks to approve a 3-D-printed plastic valve that allows two patients rather than one to be sustained on a single ventilator. The valve, developed by two universities in South Carolina, is already being used at NewYork-Presbyterian Hospital. “They say it takes a village, and in this case it really did,” said Dr. Marjorie Jenkins, dean of the University of South Carolina School of Medicine Greenville, which collaborated with Clemson University to make the valves. The swift spread of the new coronavirus is rallying countless scientists and tinkerers to address the grave shortage of medical equipment. A national hive mind has come to life on an open source Facebook group where hundreds of strangers trade tips on making respirator masks with baby wipes and paper towels, and with Project N95, an online vetted clearinghouse for hospitals that need protective gear and manufacturers with product to sell. A Stanford University lab is clinically testing a full-face respirator that uses a snorkeling mask. A high-end swimming goggle company is producing eye wear that can be customized to fit a nurse’s face. Across the country, virtual sewing circles have cropped up to make surgical masks. One woman has come up with a respirator mask that uses a bra, coffee filters and citric acid. “I think it clearly shows an amazing driver that is unique to our species — we can inconvenience the masses in order to save the few, like the old ‘Star Trek’ explanation of humanity to Spock,” said Laura Gilmour, a biomedical engineer and a business development manager at EOS, a 3-D-printing technology and services provider. A former medical device reviewer at the F.D.A., she has been advising inventors on how to make gear that meets stringent safety standards. ImageRasmus Barfred, a founder of TheMagic5, a high-end swimming goggles company.Credit...TheMagic5The F.D.A. said it appreciated the flurry of innovation, though it said it would continue to evaluate unapproved devices to ensure they meet safety and performance standards. “The F.D.A. continues to take creative and flexible approaches to address access to critical medical products in response to Covid-19,” it said in a statement. During the pandemic, it added, the need for certain equipment “may outpace the supply available to health care organizations because of the high demand and overall interruptions to the global supply chain.” Connie Steed, president of the Association for Professionals in Infection Control and Epidemiology, said she welcomed the outpouring of help, especially the homemade surgical masks and plastic face shields that have fewer technical requirements. In a survey the organization released Friday, nearly half of the 1,400 infection prevention specialists who responded said they were nearly out of respirator masks and face shields, and a third said they were running low on surgical masks. “It’s wonderful to see the creativity of people thinking of ways to help health care providers take care of sick patients and also protect themselves,” she said. “The need is critical. Every minute matters.” Latest Updates: Coronavirus Outbreak Despite pushback, Trump tells governors he “hasn’t heard about testing in weeks.” As governors beg, Trump promises ventilators to Europe. Despite scant evidence, the F.D.A. granted approval to use two malaria drugs. See more updates Updated 31m ago More live coverage: Markets New York Some of the most promising and pragmatic ideas have come from scores of university engineering labs, many of which have been seeking guidance from the F.D.A. while consulting with local hospitals or those are affiliated with their schools. Students at West Texas A&M University has come up with a copper antimicrobial patch that can be affixed to door knobs. Drexel University’s Center for Functional Fabrics is making thousands of high filtration masks that the United States military has agreed to test. Researchers at the University of Pennsylvania are tackling several types of medical equipment: respirators made out of vacuum bags, 3-D-printed face shields and ventilators that can be manufactured quickly. Penn plans to make 5,000 face shields in the coming days using 3-D-printed parts provided by hobbyists and local maker enthusiasts. ImageUriel Eisen of the Future Lab at the N.Y.U. Tandon School of Engineering, using a laser cutter to make new face guards.Credit...NYU Tandon School of EngineeringMohit Prajapati, the director of research and development, strategy and operations at Penn Medicine’s Center for Healthcare Innovation, has been overseeing the effort to use strategic folding techniques — like “origami,” he said — to create respirators out of sterilization wrap, a material that is used in N95 masks but which hospitals use to wrap sterilized medical equipment. Penn has also experimented with vacuum bags and other materials that provide some level of particle filtration. “We started off with Home Depot,” Mr. Prajapati said. Although Penn is awaiting results from a laboratory, a process that could take two weeks, it is starting to make more of the masks so they’ll be ready when and if they’re needed. “I can say for certain they are better than wrapping a bandanna around your face,” he said. Many of the ideas have come to fruition in a remarkably short time. On Thursday, the New York City Economic Development Corporation placed an order for 300,000 face shields that students, teachers and doctors at New York University designed, produced and field tested with employees at N.Y.U. Langone Health. “It started last week on a conference call where we thought, ‘What can we do to help,’ and then it took on a life of its own,” said Grant Fox, director of N.Y.U. Tandon Future Labs, which led the design. “It’s been a real brain trust.” Next up for the lab? A negative pressure hood that can be placed over the head of Covid-19 patients to prevent the virus from leaking out and infecting health care workers and other patients. Business owners are also doing what they can. Max Friefeld, the chief executive of Voodoo Manufacturing, is using his 20 employees and the company’s Brooklyn workshop to produce 500 face shields a day for hospitals in New York. For many, the mission feels personal. Shervin Pishevar, a tech start-up investor and scientist in Miami who came up with designs for a ventilator that uses 3-D-printed components, said he was motivated by his love for his parents, who have diabetes and are in their 80s. “It terrifies me to think of them getting the coronavirus and showing up at a hospital that has run out of ventilators,” he said. “They wouldn’t survive.” It’s not only entrepreneurs and university engineers who have jumped into the fray. Over the past week, Iris Friedman, the vice president of a local school board in rural upstate New York, and a seamstress friend have been making fabric face masks fitted with swatches of a vacuum cleaner bag and filters from the nearby hardware store. The masks are for several front-line health care workers, including her daughter and son-in-law, all of whom are running short of protective gear. The wire in the hardware store filters cut her fingers open as she separated the cloth. On Wednesday, she mailed the masks with a note from two other mothers in her neighborhood. “We hope they help and like the idea, in some existential way, of being so close to your faces!” the note read. “Pay attention out there and be sure that you protect yourself first, as best you can.” It was signed, “Love, the moms.”