key: cord-1000686-z7lgg0e5
authors: Runde, Daniel P.; Harland, Karisa K.; Van Heukelom, Paul; Faine, Brett; O'Shaughnessy, Patrick; Mohr, Nicholas M.
title: The “double eights mask brace” improves the fit and protection of a basic surgical mask amidst COVID‐19 pandemic
date: 2020-12-26
journal: J Am Coll Emerg Physicians Open
DOI: 10.1002/emp2.12335
sha: 577a6dd64d5dc986ce2ae246589e31b927dbafba
doc_id: 1000686
cord_uid: z7lgg0e5

STUDY OBJECTIVE: The COVID‐19 pandemic has resulted in widespread shortages of personal protective equipment, including N95 respirators. Although basic surgical facemasks are more commonly available, their efficacy is limited due primarily to their poor face seal. This pilot study examined the impact of a rubber band mask brace on a basic surgical mask, as determined by quantitative fit testing. METHODS: Subjects wearing a basic surgical facemask and the rubber band mask brace underwent quantitative fit testing using machinery designed to certify N95 mask fit. Subjects were tested with the brace anchored behind their ears, with a paperclip behind the head, and on the side knobs of their face shields. The primary outcome measure was whether the subject passed the quantitative fit test at or above the Occupational Safety and Health Administration (OSHA)‐verified standard for N95 masks. RESULTS: Subjects (n = 11) were 54.5% female, with a median height of 70 inches (interquartile range [IQR] = 68–74), weight of 170 pounds (IQR = 145–215), and body mass index (BMI) of 24.6 (IQR = 22.2–27.2), and encompassing 5 distinct N95 mask fit types. We found that 45%, 100%, and 100% of subjects passed the quantitative fit test when the brace was anchored behind the ears, with a paperclip and on a face shield, respectively. CONCLUSION: Of the 11 subjects included in the analysis, across a range of body habitus and N95 mask fit types, all passed the quantitative fit test when the mask brace was anchored on either face shield or with a paperclip. This data suggests that although the brace does not create an N95 equivalent in terms of filtration, it would offer improved protection from airborne viruses when worn with a basic surgical mask.

as these droplets will follow the path of least resistance, which is, by definition, anywhere the mask does not have a good seal with the face, negating the filtering capabilities of the mask itself. We present an improvement that can be worn with a basic surgical mask, comprised of 3 interlocking rubber bands, that substantially improves the facial seal of the mask and may allow it to serve as a substitute for the N95 respirator in times of shortage. We refer to this improvement as the "double eights mask brace." 

There However, the results of the pressure drop testing do indicate that the mask remains quite breathable when the brace is applied. It is also essential to note that filtration performance of ASTM Level 1 mask material is not equivalent to that of an N95 mask, which maintains a >95% particle capture efficiency across a wide spectrum of particle size (0.01-10 µm), a standard that a basic surgical facemask does not meet. Finally, only one surgical mask type was tested quantitatively, and the performance of the double eights mask brace in a clinical set-ting was not evaluated, which precludes drawing any definitive conclusions about its ability to prevent viral transmission.

Of the 11 subjects included in the analysis, across a range of body habitus and N95 mask fit types, all passed the quantitative fit test when the double eights mask brace was anchored on the face shield or behind the head with a paperclip, suggesting that the implement offers a substantially augmented degree of facial seal, to the point that it was able to meet the rigorous standards applied to fit tested N95 masks. Even the less robust performance of the mask brace when anchored behind the ears offered an improved seal compared to wearing the mask alone, though it appears that in this configuration, the double eights mask brace does not always apply adequate pressure around the mask to create an effective seal. Future study of the double eights mask brace will need to include analysis of brace comfort and wearability, in addition to testing on a larger cohort of individuals with a more formal assessment of facial morphology.

Given the high burden of health care worker infection and the critical shortage in PPE, the dramatic improvement in mask face seal created by this affordable and practical mask brace offers an additional margin of protection that has the potential to prevent transmission and save lives.

DPR and PVH designed the study. KKH, NMM, BF, and PO provided expertise in the interpretation of the data. DPR, NMM, and KKH were responsible for managing the data and provided oversight of statistical analyses. DPR and KKH had full access to the data set and analyzed the data. DPR and KKH drafted the article, and all authors contributed substantially to its revision. DPR takes responsibility for the paper as a whole. 

The authors have no conflicts of interest to disclose.

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