COVID-19: Simple tweaks of common devices tackle ventilator shortage

A team headed up by New York University’s Tandon School of Engineering has come up with a simple tweak of a CPAP machine—a common breathing-assist device used by patients suffering from sleep apnea—to address the looming shortage of ventilators. They’re also testing prototypes of a modification to a common salon hair dryer in hopes of limiting the spread of the virus.

Vikram Kapila, a professor of mechanical and aerospace engineering at NYU’s Tandon School of Engineering, is the team lead for the school's COVID-19 response initiative. Students in his mechatronic, controls and robotics  lab are working in collaboration with NYU Tandon’s Future Labs, MakerSpace, and the Rutgers New Jersey Medical Center.

In many ways, Kapila was an obvious choice to head up a team exploring new innovations to combat the ventilator shortage. His mechatronics lab focuses on leading edge, healthcare technologies for persons with disabilities and seniors.

“We look at some of the common health issues today and the social and economic impacts, the solutions that are currently out there, and then look at how we can develop something that a wider group could potentially benefit from,” said Kapila.

The COVID-19 initiative for coming up with ideas for assisting patients with breathing and reducing the spread of the virus involved a distributed team of students, alumni, and experts from California to Brooklyn, all working from home. Three initial criteria were followed:

  • Use equipment readily available in healthcare environments and off-the-shelf components that enable manufacturing at scale
  • Create solutions that can be quickly constructed and deployed with minimal training
  • Get upfront input and construction validation from medical professionals and others well-versed in ventilator operation and clinical environments
COVID-19 Response Team NYU

Members of NYU's COVID-19 response initiative, haling from California to Brooklyn, and places in-between collaborated remotely.

“With the use of readily available equipment top of mind, we learned that a lot of hospitals and nursing homes have CPAP and BiPAP machines for helping patients breathe, which was compelling on because if you can keep people breathing on their own while providing perhaps the much needed oxygen support, you can potentially avoid the need for a ventilator altogether,” said Kapila.

A CPAP (for continuous positive airway pressure), machine uses a hose and mask to blow air at a pressure to keep airways open. A BiPAP is similar, but delivers pressurized air at two different levels, allowing for ease during exhalation. The machines are used by millions of people in the U.S. to treat sleep apnea.

“The fact that the devices were widely in use obviously has a lot of advantages, one important one is that we didn’t want to require health care workers to do anything different,” he continued.

 “We wondered since these devices already exist, ‘Is there an issue that would prevent their use with COVID-19 patients?’ And then we learned that early on in Washington they tried to use these machines to provide breathing support for patients, and they actually caused the virus to be spread,” Kapila explained. “That’s because a CPAP mask has vents, and when the user exhales, the virus becomes aerolized.”

The team first considered putting some kind of filter directly on the mask that would allow air to go in one way and out another. “But we found these types of filters are incredibly hard to get these days, so we ruled that out,” explained Kapila.

Simple is best

Aided by engineers with real-world experience like Valentin Siderskiy, an NYU alum working on a PhD at Rutgers who had previously worked at Philips Respironics Division, the team ultimately came up with three different versions of the design they call AIRMod. All use non-vented face masks, which limit exhalation to the environment, and a simple bill of materials consisting solely of off-the-shelf components. 

“By supplying the patient with oxygen through the enrichment adapter, and by properly tuning the PEEP valves, the patient receives oxygen and air while being allowed to exhale, and you can potentially delay or avoid having that person be put on a ventilator,” said Kapila.

In the simplest version, the mask attaches to a filter joined to a Tee-connector. One channel connects to a PEEP (for positive end-expiratory pressure) valve, which is a spring-loaded device that the patient exhales against; the other to an oxygen enrichment adapter. The second design includes an additional T-connector and PEEP valve connected through an elbow connector, while the third design includes a second viral filter.

CPAP circuit sleep apnea machine

The simple version of the modification, with one PEEP valve and T-connector.

The modification to a machine takes just two minutes to perform and the parts could add only a modest cost.

Feedback from doctors at NYU Langone and biomedical engineers at Rutgers on the concepts was positive, with a strong recommendation to go with the simplest version, “So that medical professionals have fewer knobs to deal with”.

A consortium of doctors at Brooklyn hospitals also suggested that the modified home-based units could be most useful for nursing homes and urgent care centers. Many of the hospitals have stationary CPAP and BPAP machines that already allow separation for breathing in and out and the ventilator shortage in New York has not been as severe as feared.

To date, the team has given six machines to colleagues at Rutgers, NYU Langone, and the local EMS to test. Steve Kuyan, managing director of NYU Tandon Future Labs has also filed for an Emergency Use Authorization with the FDA to expedite. The team has shared the designs and assembly manual for all three AirMOD’s design online in order to promote wider adoption and has provided designs for 3D-printing of common components so that anyone can make them.

A salon staple, modified

A second innovation the team is testing is called the AIRVent--a personal negative pressure hood modified out of a standard salon hair dryer.  The idea was to come up with a low-cost version of the limited number of negative pressure rooms found in hospitals in order to limit the spread of the virus and protect workers and non-COVID-19 patients.

Such a chamber could rather easily be constructed out of a plastic container, connected to a fan and HEPA-grade filter, but the concern was scalability.

So, the team approached a company that makes conventional salon hair drying units to see if the direction of flow could be reserved to suck air in instead of blowing it out. “We picked up the phone and called them, and they literally sent us an air dryer hood for which they had changed the direction of the fan assembly to make it into a suction device, and then we added a HEPA-grade filter,” said Kapila.

AIRvent setup NYU Engineering School

 Dr. George Serrador, Associate Professor at Rutgers, readying an AIRVent for testing.

The team has already received ten hoods and with their colleagues from Rutgers are using a carbon dioxide sensor to measure to what degree the modified unit can remove expired carbon dioxide. They are also using a particle counter to measure its efficacy in scavenging 0.3 micron particles.

Lessons for the future

The lessons the team has learned from this experience will surely extend far beyond the impact on the COVID-19 crisis.

“We’re in the middle of something where people are getting infected every day,” said Kapila. “And if we can help save even one life, I can’t imagine there is any more important engineering work than this.”

Kapila says he saw himself not as a professor or mentor for the team, but as a collaborator along with everyone else.  “I have now come to understand all students have the ability to contribute in their own manner and all of those contributions are valuable,” he said.  “I think if people are given challenging problems, they can rise to that challenge. And everybody here rose up—from students to a community of alums to medical doctors and industry experts.”

From his perspective, Steven Kuyan, director of entrepreneurship at of NYU Tandon and managing director of the Future Labs, said it’s likely to spur a complete rethinking of how product innovation happens and the associated timelines.

“If a team like this can converge and in a period of two to three weeks deliver an effective product that has real merit in a commercial environment," he said, "We are going to have to ask ourselves this question: “How is it that it typically takes months or even years to launch a product, and what what can NYU Tandon and our Future Labs do to help support a paradigm shift in how future engineering problems are solved and the associated deployment to market?”


For information about receiving an NYU Tandon AirMOD or NYU Tandon AirVENT for testing, email Steven Kuyan ([email protected]).

For further information or to get involved with the NYU COVID-19 Task Force, email [email protected].


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