
Courtesy of the University of Minnesota
U of M Box Team
We’re all more familiar with surgical masks and N95s than we ever thought we’d be. But in the early days of COVID-19 in Minnesota, several local doctors realized that protection beyond masks and gowns would be key for health care workers to stay safe during critical moments of taking care of patients with coronavirus.
Not surprisingly, others around the world had already started working on the problem: Doctors in Taiwan had created a plastic box that sits over a patient’s neck and shoulders with two arm holes for a provider to reach through to deliver breathing treatments. The easily transportable, clear box protects the health care worker from droplets that may carry the virus.
At the University of Minnesota Medical School, professors Drs. Kumar Belani and Gwenyth Fischer recognized the problem–independently of each other–and the potential for an improved solution. They’d need to collaborate with other departments with unprecedented speed.
So they built a model based on the Taiwanese concept, and figured out what they wanted to change. Colleague Dr. Hai-Thien Phu, an internal medicine and pediatrics resident, had no luck finding people with aerosol science knowledge over email, so she walked over to the mechanical engineering building one day in late March. The building was deserted due to stay-at-home orders, except for Chris Hogan, a professor who was gathering the department’s supply of personal protective equipment (PPE) to donate to medical workers. He saw Phu wandering the halls and asked who she was.
“She said, ‘I’m a physician looking for an expert in aerosol science,’” says Hogan, who happens to be Editor-in-Chief of the Journal of Aerosol Science. “I’ve never had anyone say that to me.”
Phu cried from joy when she got to her car. “I finally found someone to help with this device that I thought has huge potential to save lives during this pandemic.”

Courtesy of the University of Minnesota
Ventilator Box
Since then, a team of about 17 people has collaborated on two new versions of the aerosol box. Last week, M Health Fairview hospitals launched the second version, with 11 boxes in use so far. The boxes feature four arm holes so that three health care workers can reach the patient at once, and the openings are better protected than the original. Volunteers tested Version 3.0, which features the addition of a HEPA filter on the top, over the weekend.
“It creates a chimney like when you turn on a fan, so the HEPA filter sucks up anything that is aerosolizing, like if the patient coughs or sneezes,” Belani says. “So the patient can be using bipap, high flow nasal oxygen, and it will not come into the room.”
The HEPA filter allows just three of every 10,000 particles to pass through, whereas an N95 mask allows 1 out of every 20 through, Hogan says.
“It adds an extra layer of protection,” says Fischer, who adds that health care workers would keep their PPE on while working with patients in the boxes.
The newest version could be a game-changer in the case of a local surge, Fischer says, since many patients could use the box and save negative air-pressure rooms for those who need them most.
The team believes the new version is the only model that combines three things: a rigid structure, ports for multiple providers to access the patient, and active filtration.
“We would like to have one for every Fairview hospital–and we’re getting requests from outside Fairview, too,” Fischer says.
Phu thinks the device may provide another service to patients who are currently isolated: “Hopefully if we can contain the spread of aerosol, they can be surrounded by loved ones again during these scary times,” she says.
Meanwhile, doctors at Hennepin County Medical Center have developed a similar solution: Their plastic hood is set to be published in the Annals of Emergency Medicine. Emergency department Dr. Marc Martel built a frame out of PVC piping that holds a large plastic bag, creating a tent around the patient that allows breathing treatments to continue while a patient is transported from an ambulance to the emergency room, or from the ER to the ICU. Like the plexiglass box, it also provides an extra layer of protection for health care workers. People chuckle when they see it, Martel says, but it’s been well-received by both health care workers and patients as a “goofy thing in a goofy time, but an added layer of safety.”
Dr. Rob Reardon, who collaborated with Martel, says it’s an example of simultaneous invention.
“When tons of smart people are all trying to do the right thing at the same time, these ideas often emerge simultaneously,” Reardon says.