An engineering team at the University of Idaho is literally lighting up the coronavirus and helping health care providers stretch their supplies of personal protective equipment.
The light in question is ultraviolet from the intense “C” portion of the spectrum. It has a proven track record of killing or inactivating all kinds of microorganisms, including viruses, making it a useful way to sterilize and reuse normally disposable protective gear like masks and face shields.
Medical supply companies build commercial-grade UVC cabinets, but they have been sold out for weeks because of demand brought on by the COVID-19 pandemic. And even when they are available, they can be prohibitively expensive. So when an emergency room doctor at St. Joseph Regional Medical Center in Lewiston contacted the UI College of Engineering for help designing and building a UVC cabinet, a team of electrical, mechanical and biological engineers quickly formed to tackle the problem.
UI engineering professor and team member Dev Shrestha said there was already a body of work to inform the project, so coming up with a design was relatively easy. But they were missing the most crucial component.
“The main hurdle was getting the UV lamps to build the units,” Shrestha said. “By the time we were putting this unit together, all of the UV lamps were gone from Amazon and places like that, the standard vendors.”
But one of Shrestha’s former students, city of Lewiston stormwater and wastewater engineer Joe Kaufman, found a way out of that dead end. UVC bulbs are a common part of the wastewater treatment process, and Kaufman had already asked around at local facilities to see if they had any spares for a small UVC disinfection unit he was building for his wife’s twin sister, a doctor at a Spokane hospital.
“I immediately realized that there was a need that would be coming here as a mitigation need, and coming everywhere,” Kaufman said of the motivation for building his unit. “It feels like you’re fighting back somehow.”
He based it on a design from his graduate school friend Brian Crabtree, who published the plans at www.instructables.com/id/UVC-Sterilizer-for-COVID-19-Emergency. And when Kaufman learned of the larger project at his alma mater, he used his connections to scrounge up a donation of more than 100 bulbs from the city of Clarkston’s wastewater treatment plant. The plant recently underwent an upgrade and decommissioned a bunch of its old, yet still functional, bulbs.
“He delivered the first batch of those lamps here, and then all these designs are around using that lamp,” Shrestha said. “It was a bad situation, so Joe came to the rescue and we had a lot of lamps that we could build the unit from. We still have a lot of lamps.”
The team has already built and delivered the large unit requested by St. Joseph that kicked off the whole effort. But now that it has so many more bulbs to use, the engineers put together an open-source document that has plans for any medical facility to build their own. It is available at www.uidaho.edu/engr/covid-19, along with contact information to request the UVC bulbs.
Shrestha said the college was careful to include detailed warnings, because UVC light can quickly harm the skin and eyes if not contained properly. It can also generate ozone gas, which is harmful to breathe.
“So we got the specifications and all the calculations, and we looked at (Occupational Safety and Health Administration) standards for the UV hazard and ozone hazards and put them into the document so that if anyone wants to build it that they’re aware of those hazards and can prevent those exposures,” he said.
The team completed a second unit last week to perform tests and calibrate the design even further to limit those hazards, Shrestha said. The unit will be donated to either Gritman Medical Center in Moscow or Kootenai Health in Coeur d’Alene, once testing is complete.
But with the open-source document now available to the public, anyone around the country or the globe can build their own units, as long as they can source the UVC bulbs. Shrestha said developing countries may have even more need than the U.S. for such a low-cost device that uses mostly off-the-shelf components available at any hardware store.
“I think it’s really satisfying to work on this and be part of the solution,” Shrestha said. “The team is very enthusiastic, and they are putting in time and effort to build this unit and make sure everything goes right, and we’re not creating another problem to solve one problem.”
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