Engineers at Rice University created a silicone face harness that drastically improves the protection offered by standard surgical masks against the spread of airborne droplets. The harness helps to reduce leakage around the sides of surgical masks and upgrades the protection they offer to approximately match that of higher specification N95 masks. The technology was originally developed earlier in the pandemic to help address a shortfall in N95 masks, but could be useful during future waves of COVID-19 and in low-resource regions where supplies of N95 masks are unreliable.
Not all masks are created equal, and during a future viral pandemic, poorly performing masks could be a chink in our armor. This was a particular issue during the early days of the pandemic, when high-spec N95 masks were in short supply, prompting these researchers to develop a practical solution that can enhance the protection offered by common surgical masks.
“N95s were hard to get at the time, so it seemed logical to improve the flimsy surgical masks you see in hospitals,” said Jacob Robinson, a researcher involved in the study. “Now, of course, good masks are easier to get, but you never know when our solution will be needed.”
Their solution focuses on improving the main weakness of surgical masks, their loose fit, which allows a significant amount of airborne droplets to escape the mask. To make the masks fit more snugly, the researchers developed a silicone harness that sits over the mask, and drastically reduces the droplets that can escape during use. The silicone elastomer is laser-cut from a single sheet.
To test their device, the researchers 3D printed different mannequin heads, and investigated if the harness could help improve surgical mask fit on a variety of face shapes. They also recruited volunteers and used an infrared camera to detect hot air leaving the masks as people wore them, letting them determine how leaky the masks were.
The tests allowed the researchers to refine their harness design to reduce air leakage. “That was a suggestion from clinicians at MD Anderson who told us if something is really big, it can interfere with a surgeon’s eyesight,” said Jeanette Ingabire, another scientist involved in the study. “So the final version fits more snugly around your nose. If you want people to use something for a long time, it has to be comfortable.”
The final harness design is fifteen times better at preventing droplet escape than conventional surgical masks alone, and can be sanitized for re-use.
Study in JAMA Network Open: Evaluation of Aerosol Particle Leak and Standard Surgical Mask Fit With 3 Elastomeric Harness Designs
Via: Rice University