Image from Brigham & Women’s Hospital
Brigham & Women’s Hospital says it is developing a new, sustainable alternative to N95 respirator masks that are in demand during the COVID-19 pandemic.
A team of bioengineers and clinical experts at the Boston-based hospital and the Massachusetts Institute of Technology (MIT) are working on the “injection molded autoclavable, scalable, conformable” iMASC system for providing protection during the pandemic, according to a news release out today.
The iMASC, made from sterilizable materials, is still in its prototyping stage, but early results from studies published in the British Medical Journal Open suggest that it could fit faces of different sizes and shapes, plus it could be sterilized for reuse, according to a news release.
Researchers selected Dow Corning QP1-250 liquid silicone rubber (LSR) for the mask material, as it can withstand heat rising up to 572 degrees Fahrenheit, then created masks using injection molding, plus elastic straps and two replaceable filters to keep out solid particles.
“Like many of our colleagues, when we heard about shortages in personal protective equipment, we wanted to help,” Brigham gastroenterologist, MIT biomedical engineer & corresponding author Giovanni Traverso said in the news release. “We thought that an approach that could be helpful would be to develop a mask system that could be readily sterilized in many different ways and reused.”
Traverso and the research team tested a number of sterilization methods on the masks, including autoclaving, soaking in a bleach solution and soaking in isopropanol. They observed that 10 autoclave cycles made the masks slightly stiffer, there were no large differences in the sterilized masks compared to the products before sterilization.
They also used 3D modeling to see how the mask might fit on faces of all shapes and sizes, recruiting healthcare workers from Brigham for a small fit testing study. All 20 participants completed the process, with 60% saying they were willing to wear the iMASC system instead of a surgical mask and 20% saying they had no preference. Additionally, 25% said they preferred the iMASC system over an N95, while 60% had no preference.
Authors involved in the research acknowledged the limitations of the study, namely the small sample size of the fit testing, while large-scale production would require greater quality control of filter components.
“From the beginning, we were thinking about scalability,” Brigham department of radiation oncology resident & postdoctoral fellow in the Traverso lab Dr. James Byrne said. “We selected materials recognized to be sterilizable and comfortable and a manufacturing process designed to be scaled.”