Analysis of mask fit testing based on two-dimensional photographic measurement of facial shape
Objective To investigate the pass rates of fit tests for various brands of medical protective masks and to explore methods for quickly matching these masks based on their head and face dimensions.Methods A total of 202 medical staff from designated hospitals in Tianjin were selected as subjects.Quantitative fit tests were conducted on 5 brands of masks(A,B,C,D,and E)using an aerosol condensation nucleus counter.Two-dimensional photographic measurement was used to obtain the face length and width of the subjects,categorizing them into face types#1 to#10.The pass rates of masks across different face zones,brands,and face types were compared.Results A total of 202 testers participated in this study.According to the guidelines,face type#1 was the most common[43.6%(88/202)],followed by face type#3[18.2%(37/202)].The majority of subjects were categorized as face types#1,#2,#3,and#4,totaling 176 subjects(87.1%).A total of 914 tests were conducted,with 678 passes,resulting in an overall mask pass rate of 74.18%.The pass rates of masks A,B,and C were significantly higher than those of masks D and E[87.03%(161/185),85.57%,(166/194),82.02%(146/178)vs.62.98%(114/181),51.70%(91/176),all P<0.05].The pass rate of adjustable head-mounted masks was significantly higher than that of non-adjustable masks[79.54%(587/738)vs.51.70%(91/176),P<0.05].The fit factor(FF)for mask B in face types#1 to#5 was significantly higher than that in face types#6 to#10[200(163,200)vs.132(86,200),P<0.05].Conclusions Two-dimensional photographic measurement can quickly obtain facial information of the subjects and match the corresponding masks.Hospitals can match masks with higher test pass rates according to the proportion of face types among medical staff.When selecting masks,preference should be given to adjustable head-mounted masks.