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OBJECTIVE@#In order to find whether there is the correlation between the non-oil particle filtration efficiency(PFE) and the bacterial filtration efficiency(BFE) of medical surgical masks.@*METHODS@#Non-oil particle filtration efficiency and bacterial filtration efficiency were compared and analyzed through the test data of medical surgical masks from 2012 to 2018.@*RESULTS@#When the non-oil particle filtration efficiency of medical surgical mask is over 80%, the bacterial filtration efficiency can reach 95%.@*CONCLUSIONS@#In order to reach the requirement of 95% bacterial filtration efficiency, surgical medical mask must improve the limit of non-oil particle filtration efficiency. The results of data analysis can provide reference for emergency inspection and filter material rapid inspection, and also provide reference for the revision of YY 0469 standard.
Subject(s)
Filtration , Masks , Particle SizeABSTRACT
Objective To investigate filtration efficiency of convertible vena cava filters on treating pulmonary embolism under the condition of different thrombus diameters and contents.Methods Three kinds of convertible vena cava filter models with different filtering unit structures (L-style,S-style,W-style) were constructed to numerically simulate hemodynamics based on computational fluid dynamic (CFD) methods,and their filtration efficiency was comparatively analyzed under the condition of different thrombus diameters (5,10,15 mm) and contents (10％,15％,20％).Results With the increasing of thrombus diameter and content,the volume fraction of thrombus distributed on the filter bars increased and the filtration efficiency of the filter became better.When the thrombus diameter was 5 mm,the S-style filter's filtration efficiency was the best as compared with the other two kinds of filters.When the thrombus diameter was 10 mm,the W-style filter showed the best filtration efficiency.When the thrombus diameter was 15 mm,the S-style and W-style filter showed the same filtration efficiency,which was better than the L-style filter.Conclusions The implantation of vena cava filters will cause hemodynamic changes,and its filtration efficiency is not only related to filtering unit structures,but also closely related to the diameter and content of thrombus.These results provide a theoretical reference basis for the design and clinical choice of the novel convertible vena cava filter.
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Objective To investigate filtration efficiency of convertible vena cava filters on treating pulmonary embolism under the condition of different thrombus diameter and content. Methods Three kinds of convertible vena cava filter models with different filtering unit structures (L-style, S-style, W-style) were constructed to numerically simulate hemodynamics based on computational fluid dynamic (CFD) methods, and their filtration efficiency were comparatively analyzed under the condition of different thrombus diameter (5, 10, 15 mm) and content (10%, 15%, 20%). Results With the increasing of thrombus diameter and content, the volume fraction of thrombus distributed on the filter bars increased and filtration efficiency of the filter became better. When the thrombus diameter was 5 mm, the S-style filter’s filtration efficiency was the best as compared with the other two styles of filters. When the thrombus diameter was 10 mm, the W-style filter showed the best filtration efficiency. When the thrombus diameter was 15 mm, the S-style and W-style filter showed the same filtration efficiency, which was better than the L-style filter. Conclusions The implantation of vena cava filters will cause hemodynamic changes, and its filtration efficiency is not only related to filtering unit structures, but also closely related to the diameter and content of thrombus. These results provide a theoretical reference basis for the design and clinical choice of the novel convertible vena cava filter.
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Objective To investigate filtration efficiency of convertible vena cava filters on treating pulmonary embolism under the condition of different thrombus diameters and contents.Methods Three kinds of convertible vena cava filter models with different filtering unit structures (L-style,S-style,W-style) were constructed to numerically simulate hemodynamics based on computational fluid dynamic (CFD) methods,and their filtration efficiency was comparatively analyzed under the condition of different thrombus diameters (5,10,15 mm) and contents (10％,15％,20％).Results With the increasing of thrombus diameter and content,the volume fraction of thrombus distributed on the filter bars increased and the filtration efficiency of the filter became better.When the thrombus diameter was 5 mm,the S-style filter's filtration efficiency was the best as compared with the other two kinds of filters.When the thrombus diameter was 10 mm,the W-style filter showed the best filtration efficiency.When the thrombus diameter was 15 mm,the S-style and W-style filter showed the same filtration efficiency,which was better than the L-style filter.Conclusions The implantation of vena cava filters will cause hemodynamic changes,and its filtration efficiency is not only related to filtering unit structures,but also closely related to the diameter and content of thrombus.These results provide a theoretical reference basis for the design and clinical choice of the novel convertible vena cava filter.
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Objective To investigate filtration efficiency of convertible vena cava filters on treating pulmonary embolism under the condition of different thrombus diameters and contents.Methods Three kinds of convertible vena cava filter models with different filtering unit structures (L-style,S-style,W-style) were constructed to numerically simulate hemodynamics based on computational fluid dynamic (CFD) methods,and their filtration efficiency was comparatively analyzed under the condition of different thrombus diameters (5,10,15 mm) and contents (10％,15％,20％).Results With the increasing of thrombus diameter and content,the volume fraction of thrombus distributed on the filter bars increased and the filtration efficiency of the filter became better.When the thrombus diameter was 5 mm,the S-style filter's filtration efficiency was the best as compared with the other two kinds of filters.When the thrombus diameter was 10 mm,the W-style filter showed the best filtration efficiency.When the thrombus diameter was 15 mm,the S-style and W-style filter showed the same filtration efficiency,which was better than the L-style filter.Conclusions The implantation of vena cava filters will cause hemodynamic changes,and its filtration efficiency is not only related to filtering unit structures,but also closely related to the diameter and content of thrombus.These results provide a theoretical reference basis for the design and clinical choice of the novel convertible vena cava filter.
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Objective: To study the structure property of a superfine melt blow(MF) non woven material for making medical masks and its filtering functions. Methods: Five kinds of masks were tested and they were: 20 layer gauze mask, cotton spunlace mask, MF outpatient mask, MF medical protective mask Ⅰ and MF medical protective mask Ⅱ. Scanning electron microscope was used to observe the structure of the filtering materials. The aperture of the materials was measured and the filtering efficacy was tested. Results: The diameter of MF fibers was less than 3 ?m and the material made from it was randomly distributed with multi curve channels and complex structure. The filtering efficacy of the new material was 96.2% 99.5% for ambient aerosol particles with a diameter of 0.3 ?m, while the efficacy of 20 layer gauze mask was 50.9%. As for respiratory resistance the former was 26 43 Pa and the later was 48 Pa. Besides, MF mask had good humid proof function and the character of electronic charge, and the later could help capture the particles. Conclusion: The new masks made from MF material has good filtering function and low respiratory resistance, which can be used to prevent SARS virus.