ON THE FRONT LINES: Penn Medicine Princeton Medical Center nurses received the personal protective equipment they needed in the battle against COVID-19 when Princeton University graduate students and faculty answered the call to create face shields and the more sophisticated “PAPR” covers, face-and-neck coverings that integrate with the powered air purifying respirators needed for treating the most high-risk patients. (Photo courtesy of Penn Medicine Princeton Health)

By Donald Gilpin

As the COVID-19 pandemic rages on, with new cases and hospitalizations on the rise, teams of Princeton University faculty, students, and postdoctoral fellows continue to create vital personal protective equipment (PPE) for frontline health care workers at Penn Medicine Princeton Medical Center (PMC) and other hospitals. 

The grad students and professors from across academic departments responded to an urgent request from Princeton Medical Center last spring and have since delivered more than 3,000 reusable face shields to hospital staff, as well as 1,500 specialized covers for the powered air purifying respirators (PAPRs) used by medical workers in high-risk environments. University labs are currently responding to a request for 1,000 more PAPR covers.

Princeton professors Daniel Cohen, from the mechanical and aerospace engineering department, and Daniel Notterman, a pediatrician in the department of molecular biology, have coordinated the research efforts in response to calls for assistance from doctors and hospitals.

“I was looking for a way to help,” said Cohen, who conducts a seminar in which he connects engineering students and health care professionals interested in improving medical technology. Design for the face shields was not difficult for Cohen and his team, but the challenge was to find materials, particularly plastics. 

They set up a system where first the purchasing departments at PMC and Robert Wood Johnson University Hospital provided the materials, then team captains collected the parts and delivered them to volunteer assemblers (including a core group from Princeton Neuroscience Institute), then volunteers assembled the shields before the captains picked up the finished devices and returned them for delivery.

The entire process, according to the University Office of Communication, was reviewed by the Office of the Provost’s committee on volunteer COVID-related activities, as everyone worked safely, quickly, and without need for close contact.

The PAPR project was much more complex, according to a University press release.  PAPRS, resembling full-face scuba masks, are safer and better to use than standard face shields, but in order to work, the PAPR chin cover has to be protective, flexible, and elastically sealed from the neck up to the ears. PAPRs are used mainly in surgery and high-risk procedures.

Kari Mastro, the director of practice, innovation, and research at PMC, had worked years before as an intensive care nurse with Notterman, and served as a key contact for the Princeton University team.

Mastro noted that it was difficult to obtain enough PAPR covers, because they are relatively complex, meant for single-use only, and in high demand during the pandemic. 

Cohen’s team took about a week to replicate the design, with reusable and available parts. “We buy silicone for the lab, and it turns out the silicone is shipped between protective sheets that are the same kind of plastic used in the visors,” Cohen said. “As this material by itself was in extremely short supply across the world at this point, we used the packaging plastic for the visors and returned the silicone into the bonded face-and-neck gaskets.”

In  April the team sent the PAPR prototype to Penn Medicine Princeton Medical Center, and the response was to send as many as possible immediately. The hospital had seen a sudden increase in the number of patients with COVID-19, and its supply of PAPR covers was down to three.

Cohen and his graduate student Matt Heinrich created the components of the PAPR covers that they shipped to teams of volunteer assemblers, and eventually they sent the design to their suppliers, who pre-cut the pieces ad returned them for assembly in the Princeton labs.  More than 1,500 have now been assembled. 

Pointing out that the Princeton PAPR cover design is more durable than the standard cover, Mastro said that Princeton Medical Center is grateful to be receiving further support from Cohen’s team with the current request for 1,000 more PAPR covers.

“We cannot thank the Princeton University engineering team enough for sharing their expertise to support our resilient, dedicated staff and physicians,” she said. “Knowing that they had the PPE needed to protect themselves and their patients gave our staff greater peace of mind as they carried out their mission of providing exceptional care.”

Mastro went on to emphasize the urgency of the current situation. “The supply of PPE across the country is stressed as we enter the winter months and COVID-19 cases continue to rise,” she said. “We have enough PPE to ensure the safety of our team here at Penn Medicine Princeton Health right now, but we want to be sure we remain prepared.”

The PPE work was one of a number of early initiatives by Princeton University, in addition to ongoing COVID research, to support efforts to combat the pandemic.