1
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Ikawa T, Fujita K, Kiuchi S, Li M, Kushima A, Takase H, Das B, Morita M, Todo H, Pennington M, Sugihara K. Development of a desktop mask charger. Heliyon 2023; 9:e15359. [PMID: 37089360 PMCID: PMC10080910 DOI: 10.1016/j.heliyon.2023.e15359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 03/12/2023] [Accepted: 04/04/2023] [Indexed: 04/25/2023] Open
Abstract
Polypropylene mesh, integrated in N95 respirators and surgical masks that are widely used in the current crisis of COVID-19, filters aerosols via electrostatics in addition to the physical block. However, any contact to water such as storage under high humidity, exposure to exhaling breath, and washing in water removes its charges and thus compromises its filtering efficiency. We developed a desk top device based on a Cockcroft-Walton's voltage multiplier that can restore the electrostatic charge of surgical masks within 1 min and recover the filtering efficiency of the polypropylene mesh from 87% to 97%. The device is easy to operate and safe, thus may be applied for the reuse of surgical masks towards reducing the plastic wastes.
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Affiliation(s)
- Taisuke Ikawa
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-Ku, Tokyo 153-8505, Japan
| | - Kaito Fujita
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-Ku, Tokyo 153-8505, Japan
| | - Shota Kiuchi
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-Ku, Tokyo 153-8505, Japan
| | - Muhang Li
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-Ku, Tokyo 153-8505, Japan
| | - Atsuhito Kushima
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-Ku, Tokyo 153-8505, Japan
| | - Hayato Takase
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-Ku, Tokyo 153-8505, Japan
| | - Bratati Das
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-Ku, Tokyo 153-8505, Japan
| | - Megumi Morita
- Shirohato Co., Ltd., 121-1 yayoicho Minami-ku, Nagoya-shi, Aichi 457-0027, Japan
| | - Hiroyuki Todo
- Shirohato Co., Ltd., 121-1 yayoicho Minami-ku, Nagoya-shi, Aichi 457-0027, Japan
| | - Miles Pennington
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-Ku, Tokyo 153-8505, Japan
| | - Kaori Sugihara
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-Ku, Tokyo 153-8505, Japan
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2
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Wang AB, Zhang X, Gao LJ, Zhang T, Xu HJ, Bi YJ. A Review of Filtration Performance of Protective Masks. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:2346. [PMID: 36767714 PMCID: PMC9915213 DOI: 10.3390/ijerph20032346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/20/2023] [Accepted: 01/25/2023] [Indexed: 06/18/2023]
Abstract
Masks are essential and effective small protective devices used to protect the general public against infections such as COVID-19. However, available systematic reviews and summaries on the filtration performance of masks are lacking. Therefore, in order to investigate the filtration performance of masks, filtration mechanisms, mask characteristics, and the relationships between influencing factors and protective performance were first analyzed through mask evaluations. The summary of filtration mechanisms and mask characteristics provides readers with a clear and easy-to-understand theoretical cognition. Then, a detailed analysis of influencing factors and the relationships between the influencing factors and filtration performance is presented in. The influence of the aerosol size and type on filtration performance is nonlinear and nonconstant, and filtration efficiency decreases with an increase in the gas flow rate; moreover, fitness plays a decisive role in the protective effects of masks. It is recommended that the public should wear surgical masks to prevent COVID-19 infection in low-risk and non-densely populated areas. Future research should focus on fitness tests, and the formulation of standards should also be accelerated. This paper provides a systematic review that will be helpful for the design of masks and public health in the future.
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Affiliation(s)
- Ao-Bing Wang
- Hebei Key Laboratory of Man-machine Environmental Thermal Control Technology and Equipment, Filtration Performance and Environmental Health of Protective Materials, Xingtai 054000, China
- Advanced Research Center of Thermal and New Energy Technologies, Hebei Vocational University of Technology and Engineering, Xingtai 054000, China
| | - Xin Zhang
- Hebei Key Laboratory of Man-machine Environmental Thermal Control Technology and Equipment, Filtration Performance and Environmental Health of Protective Materials, Xingtai 054000, China
- Advanced Research Center of Thermal and New Energy Technologies, Hebei Vocational University of Technology and Engineering, Xingtai 054000, China
| | - Li-Jun Gao
- Hebei Key Laboratory of Man-machine Environmental Thermal Control Technology and Equipment, Filtration Performance and Environmental Health of Protective Materials, Xingtai 054000, China
- Advanced Research Center of Thermal and New Energy Technologies, Hebei Vocational University of Technology and Engineering, Xingtai 054000, China
| | - Tao Zhang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Hui-Juan Xu
- Hebei Key Laboratory of Man-machine Environmental Thermal Control Technology and Equipment, Filtration Performance and Environmental Health of Protective Materials, Xingtai 054000, China
- Advanced Research Center of Thermal and New Energy Technologies, Hebei Vocational University of Technology and Engineering, Xingtai 054000, China
| | - Yan-Jun Bi
- Hebei Key Laboratory of Man-machine Environmental Thermal Control Technology and Equipment, Filtration Performance and Environmental Health of Protective Materials, Xingtai 054000, China
- Advanced Research Center of Thermal and New Energy Technologies, Hebei Vocational University of Technology and Engineering, Xingtai 054000, China
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3
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Whyte HE, Montigaud Y, Audoux E, Verhoeven P, Prier A, Leclerc L, Sarry G, Laurent C, Le Coq L, Joubert A, Pourchez J. Comparison of bacterial filtration efficiency vs. particle filtration efficiency to assess the performance of non-medical face masks. Sci Rep 2022; 12:1188. [PMID: 35075199 PMCID: PMC8786818 DOI: 10.1038/s41598-022-05245-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/05/2022] [Indexed: 11/09/2022] Open
Abstract
As a result of the current COVID-19 pandemic, the use of facemasks has become commonplace. The performance of medical facemasks is assessed using Bacterial Filtration Efficiency (BFE) tests. However, as BFE tests, require specific expertise and equipment and are time-consuming, the performance of non-medical facemasks is assessed with non-biological Particle Filtration Efficiency (PFE) tests which are comparatively easier to implement. It is necessary to better understand the possible correlations between BFE and PFE to be able to compare the performances of the different types of masks (medical vs. non-medical). In this study BFE results obtained in accordance with the standard EN 14683 are compared to the results of PFE from a reference test protocol defined by AFNOR SPEC S76-001 with the aim to determine if BFE could be predicted from PFE. Our results showed a correlation between PFE and BFE. It was also observed that PFE values were higher than BFE and this was attributed to the difference in particle size distribution considered for efficiency calculation. In order to properly compare these test protocols for a better deduction, it would be interesting to compare the filtration efficiency for a similar granulometric range.
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Affiliation(s)
- Henrietta Essie Whyte
- Mines Saint-Etienne, Université Lyon, Université Jean Monnet, INSERM, U 1059 Sainbiose, Centre CIS, 42023, Saint-Etienne, France. .,IMT Atlantique, CNRS, GEPEA, UMR 6144, 4 rue Alfred Kastler, 44307, Nantes, France.
| | - Yoann Montigaud
- Mines Saint-Etienne, Université Lyon, Université Jean Monnet, INSERM, U 1059 Sainbiose, Centre CIS, 42023, Saint-Etienne, France
| | - Estelle Audoux
- CIRI (Centre International de Recherche en Infectiologie), GIMAP Team, University of Lyon, University of St-Etienne, INSERM, U1111, CNRS UMR5308, ENS de Lyon, UCB Lyon 1, St-Etienne, France
| | - Paul Verhoeven
- CIRI (Centre International de Recherche en Infectiologie), GIMAP Team, University of Lyon, University of St-Etienne, INSERM, U1111, CNRS UMR5308, ENS de Lyon, UCB Lyon 1, St-Etienne, France.,Laboratory of Infectious Agents and Hygiene, University Hospital of St-Etienne, St-Etienne, France
| | - Amélie Prier
- CIRI (Centre International de Recherche en Infectiologie), GIMAP Team, University of Lyon, University of St-Etienne, INSERM, U1111, CNRS UMR5308, ENS de Lyon, UCB Lyon 1, St-Etienne, France
| | - Lara Leclerc
- Mines Saint-Etienne, Université Lyon, Université Jean Monnet, INSERM, U 1059 Sainbiose, Centre CIS, 42023, Saint-Etienne, France
| | - Gwendoline Sarry
- Mines Saint-Etienne, Université Lyon, Université Jean Monnet, INSERM, U 1059 Sainbiose, Centre CIS, 42023, Saint-Etienne, France
| | - Coralie Laurent
- Mines Saint-Etienne, Université Lyon, Université Jean Monnet, INSERM, U 1059 Sainbiose, Centre CIS, 42023, Saint-Etienne, France
| | - Laurence Le Coq
- IMT Atlantique, CNRS, GEPEA, UMR 6144, 4 rue Alfred Kastler, 44307, Nantes, France
| | - Aurélie Joubert
- IMT Atlantique, CNRS, GEPEA, UMR 6144, 4 rue Alfred Kastler, 44307, Nantes, France
| | - Jérémie Pourchez
- Mines Saint-Etienne, Université Lyon, Université Jean Monnet, INSERM, U 1059 Sainbiose, Centre CIS, 42023, Saint-Etienne, France
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4
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Processing and Quality Control of Masks: A Review. Polymers (Basel) 2022; 14:polym14020291. [PMID: 35054695 PMCID: PMC8778442 DOI: 10.3390/polym14020291] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/08/2021] [Accepted: 11/12/2021] [Indexed: 12/19/2022] Open
Abstract
It is clear that viruses, especially COVID-19, can cause infection and injure the human body. These viruses can transfer in different ways, such as in air transfer, which face masks can prevent and reduce. Face masks can protect humans through their filtration function. They include different types and mechanisms of filtration whose performance depends on the texture of the fabric, the latter of which is strongly related to the manufacturing method. Thus, scientists should enrich the information on mask production and quality control by applying a wide variety of tests, such as leakage, dynamic respiratory resistance (DBR), etc. In addition, the primary manufacturing methods (meltblown, spunlaid, drylaid, wetlaid and airlaid) and new additive manufacturing (AM) methods (such as FDM) should be considered. These methods are covered in this study.
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5
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Li R, Zhang M, Wu Y, Tang P, Sun G, Wang L, Mandal S, Wang L, Lang J, Passalacqua A, Subramaniam S, Song G. What We Are Learning from COVID-19 for Respiratory Protection: Contemporary and Emerging Issues. Polymers (Basel) 2021; 13:4165. [PMID: 34883668 PMCID: PMC8659889 DOI: 10.3390/polym13234165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 02/07/2023] Open
Abstract
Infectious respiratory diseases such as the current COVID-19 have caused public health crises and interfered with social activity. Given the complexity of these novel infectious diseases, their dynamic nature, along with rapid changes in social and occupational environments, technology, and means of interpersonal interaction, respiratory protective devices (RPDs) play a crucial role in controlling infection, particularly for viruses like SARS-CoV-2 that have a high transmission rate, strong viability, multiple infection routes and mechanisms, and emerging new variants that could reduce the efficacy of existing vaccines. Evidence of asymptomatic and pre-symptomatic transmissions further highlights the importance of a universal adoption of RPDs. RPDs have substantially improved over the past 100 years due to advances in technology, materials, and medical knowledge. However, several issues still need to be addressed such as engineering performance, comfort, testing standards, compliance monitoring, and regulations, especially considering the recent emergence of pathogens with novel transmission characteristics. In this review, we summarize existing knowledge and understanding on respiratory infectious diseases and their protection, discuss the emerging issues that influence the resulting protective and comfort performance of the RPDs, and provide insights in the identified knowledge gaps and future directions with diverse perspectives.
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Affiliation(s)
- Rui Li
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Mengying Zhang
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Yulin Wu
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Peixin Tang
- Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA; (P.T.); (G.S.)
| | - Gang Sun
- Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA; (P.T.); (G.S.)
| | - Liwen Wang
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Sumit Mandal
- Department of Design, Housing and Merchandising, Oklahoma State University, Stillwater, OK 74078, USA;
| | - Lizhi Wang
- Department of Industrial and Manufacturing Systems Engineering, Iowa State University, Ames, IA 50010, USA;
| | - James Lang
- Department of Kinesiology, Iowa State University, Ames, IA 50010, USA;
| | - Alberto Passalacqua
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50010, USA; (A.P.); (S.S.)
| | - Shankar Subramaniam
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50010, USA; (A.P.); (S.S.)
| | - Guowen Song
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
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6
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El-Atab N, Mishra RB, Hussain MM. Toward nanotechnology-enabled face masks against SARS-CoV-2 and pandemic respiratory diseases. NANOTECHNOLOGY 2021; 33:062006. [PMID: 34727530 DOI: 10.1088/1361-6528/ac3578] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 11/02/2021] [Indexed: 06/13/2023]
Abstract
Wearing a face mask has become a necessity following the outbreak of the coronavirus (COVID-19) disease, where its effectiveness in containing the pandemic has been confirmed. Nevertheless, the pandemic has revealed major deficiencies in the ability to manufacture and ramp up worldwide production of efficient surgical-grade face masks. As a result, many researchers have focused their efforts on the development of low cost, smart and effective face covers. In this article, following a short introduction concerning face mask requirements, the different nanotechnology-enabled techniques for achieving better protection against the SARS-CoV-2 virus are reviewed, including the development of nanoporous and nanofibrous membranes in addition to triboelectric nanogenerators based masks, which can filter the virus using various mechanisms such as straining, electrostatic attraction and electrocution. The development of nanomaterials-based mask coatings to achieve virus repellent and sterilizing capabilities, including antiviral, hydrophobic and photothermal features are also discussed. Finally, the usability of nanotechnology-enabled face masks is discussed and compared with that of current commercial-grade N95 masks. To conclude, we highlight the challenges associated with the quick transfer of nanomaterials-enabled face masks and provide an overall outlook of the importance of nanotechnology in counteracting the COVID-19 and future pandemics.
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Affiliation(s)
- Nazek El-Atab
- Smart, Advanced Memory devices and Applications (SAMA) Lab, Electrical & Computer Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Rishabh B Mishra
- Smart, Advanced Memory devices and Applications (SAMA) Lab, Electrical & Computer Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
- MMH Labs, Electrical & Computer Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Muhammad M Hussain
- MMH Labs, Electrical & Computer Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
- Electrical Engineering and Computer Sciences (EECS), University of California, Berkeley, CA 94720-1170, United States of America
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7
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Locke L, Dada O, Shedd JS. Aerosol Transmission of Infectious Disease and the Efficacy of Personal Protective Equipment (PPE): A Systematic Review. J Occup Environ Med 2021; 63:e783-e791. [PMID: 34419986 PMCID: PMC8562920 DOI: 10.1097/jom.0000000000002366] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Health care professionals and governmental agencies are in consensus regarding contact and droplet transmission of infectious diseases. However, personal protective equipment (PPE) efficacy is not considered for aerosol or airborne transmission of infectious diseases. This review discusses the inhalation of virus-laden aerosols as a viable mechanism of transmission of various respiratory infectious diseases and PPE efficacy. METHODS The Preferred Reporting Items for Systematic reviews, and Meta-Analysis (PRISMA) guidelines was used. RESULTS The transmission of infectious disease is of concern for all respirable diseases discussed (SARS-CoV-1, SARS-CoV-2, MERS, influenza, and tuberculosis), and the effectiveness of facemasks is dependent on the efficiency of the filter, fit, and proper use. CONCLUSION PPE should be the last resort in preventing the spread of infectious disease and should only be used for protection and not to control the transmission.
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Affiliation(s)
- Laramie Locke
- Department of Occupational Safety and Health, Murray State University, Kentucky (Mr Locke, Dr Dada); Eastman Chemical Company, Tennessee (Mr Locke); and Department of Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, Alabama (Mr Shedd)
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8
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Johansson B. Challenges and Controversies in COVID-19: Masking the General Population may Attenuate This Pandemic's Outbreak. Front Public Health 2021; 9:643991. [PMID: 34568248 PMCID: PMC8455895 DOI: 10.3389/fpubh.2021.643991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 06/22/2021] [Indexed: 11/13/2022] Open
Abstract
SARS-CoV-2, the virus that causes COVID-19, spreads i. a., by respiratory droplets. The use of masks in preventing spread is controversial; masks are considered useless by many, while being mandated in some locations. Here, the effect of masking the general population on a COVID-19-like epidemic is estimated by computer simulation using three separate types of software. The main questions are whether mask use by the general population can limit the spread of SARS-CoV-2 in a country and how to identify opportunities when mask use is cost-effective and safe. To address these questions, the protective effects of different types of masks, the side-effects of masks, and avenues for improvements of masks and masking are addressed. Main results: (i) Any type of mask, even simple home-made ones, may be of value, even if the protective effect of each mask (here dubbed "one mask-protection") is low. Strict adherence to mask use does not appear to be critical but increasing one mask-protection to >50% was found to be advantageous. (ii) Masks do seem to reduce the number of new cases even if introduced at a late stage in an epidemic, but early implementation helps reduce the cumulative and total number of cases. (iii) The simulations suggest that it might be possible to eliminate a COVID-19 outbreak by widespread mask use during a limited period. There is a brief discussion of why the reported effect size of masking varies widely, and is expected to do so, because of different filtration abilities of different masks, differences in compliance and fitting, other routes of transmission, pre-existing immunity, and because a system of interconnected, disease-prone individuals has non-linear properties. A software solution to visualize infection spread is presented. The results from these simulations are encouraging, but do not necessarily represent the real-life situation, so it is suggested that clinical trials of masks are now carried out while continuously monitoring effects and side-effects. As mask use is not without risks and costs, it is suggested that governments and scientists have an important role in advising the public about the sensible use of masks.
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Affiliation(s)
- Björn Johansson
- Theme Aging, Karolinska University Hospital, Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
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9
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Margarucci LM, Gianfranceschi G, Romano Spica V, D’Ermo G, Refi C, Podico M, Vitali M, Romano F, Valeriani F. Photocatalytic Treatments for Personal Protective Equipment: Experimental Microbiological Investigations and Perspectives for the Enhancement of Antimicrobial Activity by Micrometric TiO 2. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:8662. [PMID: 34444411 PMCID: PMC8391258 DOI: 10.3390/ijerph18168662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/06/2021] [Accepted: 08/13/2021] [Indexed: 01/14/2023]
Abstract
The COVID-19 pandemic has led to countries enforcing the use of facial masks to prevent contagion. However, acquisition, reuse, and disposal of personal protective equipment (PPE) has generated problems, in regard to the safety of individuals and environmental sustainability. Effective strategies to reprocess and disinfect PPE are needed to improve the efficacy and durability of this equipment and to reduce waste load. Thus, the addition of photocatalytic materials to these materials, combined with light exposure at specific wavelengths, may represent promising solutions. To this aim, we prepared a series of masks by depositing micrometer-sized TiO2 on the external surfaces; the masks were then contaminated with droplets of bacteria suspensions and the coatings were activated by light radiation at different wavelengths. A significant reduction in the microbial load (over 90%, p < 0.01) was observed using both Gram negative (E. coli) and Gram positive (S. aureus) bacteria within 15 min of irradiation, with UV or visible light, including sunlight or artificial sources. Our results support the need for further investigations on self-disinfecting masks and other disposable PPE, which could positively impact (i) the safety of operators/workers, and (ii) environmental sustainability in different occupational or recreational settings.
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Affiliation(s)
- Lory Marika Margarucci
- Department of Movement, Human, and Health Sciences, Laboratory of Epidemiology and Biotechnologies, University of Rome “Foro Italico”, 00135 Rome, Italy; (L.M.M.); (G.G.); (F.V.)
| | - Gianluca Gianfranceschi
- Department of Movement, Human, and Health Sciences, Laboratory of Epidemiology and Biotechnologies, University of Rome “Foro Italico”, 00135 Rome, Italy; (L.M.M.); (G.G.); (F.V.)
| | - Vincenzo Romano Spica
- Department of Movement, Human, and Health Sciences, Laboratory of Epidemiology and Biotechnologies, University of Rome “Foro Italico”, 00135 Rome, Italy; (L.M.M.); (G.G.); (F.V.)
| | - Giuseppe D’Ermo
- Department of Surgery “P. Valdoni”, Sapienza University of Rome, 00185 Rome, Italy;
| | | | - Maurizio Podico
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy;
| | - Matteo Vitali
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185 Rome, Italy; (M.V.); (F.R.)
| | - Ferdinando Romano
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185 Rome, Italy; (M.V.); (F.R.)
| | - Federica Valeriani
- Department of Movement, Human, and Health Sciences, Laboratory of Epidemiology and Biotechnologies, University of Rome “Foro Italico”, 00135 Rome, Italy; (L.M.M.); (G.G.); (F.V.)
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10
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Persson BNJ. Side-leakage of face mask. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2021; 44:75. [PMID: 34089395 PMCID: PMC8179097 DOI: 10.1140/epje/s10189-021-00081-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/20/2021] [Indexed: 05/02/2023]
Abstract
Face masks are used to trap particles (or fluid drops) in a porous material (filter) in order to avoid or reduce the transfer of particles between the human lungs (or mouth and nose) and the external environment. The air exchange between the lungs and the environment is assumed to occur through the face mask filter. However, if the resistance to air flow through the filter is high some air (and accompanied particles) will leak through the filter-skin interface. In this paper I will present a model study of the side-leakage problem.
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Affiliation(s)
- B N J Persson
- PGI-1, FZ Jülich, Jülich, Germany.
- Multiscale Consulting, Wolfshovener str. 2, 52428, Jülich, Germany.
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11
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Hariharan P, Sharma N, Guha S, Banerjee RK, D'Souza G, Myers MR. A computational model for predicting changes in infection dynamics due to leakage through N95 respirators. Sci Rep 2021; 11:10690. [PMID: 34021181 PMCID: PMC8140115 DOI: 10.1038/s41598-021-89604-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/26/2021] [Indexed: 12/02/2022] Open
Abstract
In the absence of fit-testing, leakage of aerosolized pathogens through the gaps between the face and N95 respirators could compromise the effectiveness of the device and increase the risk of infection for the exposed population. To address this issue, we have developed a model to estimate the increase in risk of infection resulting from aerosols leaking through gaps between the face and N95 respirators. The gaps between anthropometric face-geometry and N95 respirators were scanned using computed tomography. The gap profiles were subsequently input into CFD models. The amount of aerosol leakage was predicted by the CFD simulations. Leakage levels were validated using experimental data obtained using manikins. The computed amounts of aerosol transmitted to the respiratory system, with and without leaks, were then linked to a risk-assessment model to predict the infection risk for a sample population. An influenza outbreak in which 50% of the population deployed respirators was considered for risk assessment. Our results showed that the leakage predicted by the CFD model matched the experimental data within about 13%. Depending upon the fit between the headform and the respirator, the inward leakage for the aerosols ranged between 30 and 95%. In addition, the non-fit-tested respirator lowered the infection rate from 97% (for no protection) to between 42 and 80%, but not to the same level as the fit-tested respirators (12%). The CFD-based leakage model, combined with the risk-assessment model, can be useful in optimizing protection strategies for a given population exposed to a pathogenic aerosol.
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Affiliation(s)
- Prasanna Hariharan
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, USA.
| | - Neha Sharma
- University of Cincinnati, 2600 Clifton Ave., Cincinnati, OH, 45221, USA
| | - Suvajyoti Guha
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, USA
| | - Rupak K Banerjee
- University of Cincinnati, 2600 Clifton Ave., Cincinnati, OH, 45221, USA
| | - Gavin D'Souza
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, USA
| | - Matthew R Myers
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, USA
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Holm SM, Miller MD, Balmes JR. Health effects of wildfire smoke in children and public health tools: a narrative review. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2021; 31:1-20. [PMID: 32952154 PMCID: PMC7502220 DOI: 10.1038/s41370-020-00267-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 09/07/2020] [Accepted: 09/11/2020] [Indexed: 05/20/2023]
Abstract
Wildfire smoke is an increasing environmental health threat to which children are particularly vulnerable, for both physiologic and behavioral reasons. To address the need for improved public health messaging this review summarizes current knowledge and knowledge gaps in the health effects of wildfire smoke in children, as well as tools for public health response aimed at children, including consideration of low-cost sensor data, respirators, and exposures in school environments. There is an established literature of health effects in children from components of ambient air pollution, which are also present in wildfire smoke, and an emerging literature on the effects of wildfire smoke, particularly for respiratory outcomes. Low-cost particulate sensors demonstrate the spatial variability of pollution, including wildfire smoke, where children live and play. Surgical masks and respirators can provide limited protection for children during wildfire events, with expected decreases of roughly 20% and 80% for surgical masks and N95 respirators, respectively. Schools should improve filtration to reduce exposure of our nation's children to smoke during wildfire events. The evidence base described may help clinical and public health authorities provide accurate information to families to improve their decision making.
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Affiliation(s)
- Stephanie M Holm
- Western States Pediatric Environmental Health Specialty Unit, University of California San Francisco, San Francisco, CA, USA.
- Division of Occupational and Environmental Medicine, University of California San Francisco, San Francisco, CA, USA.
- Division of Epidemiology, School of Public Health, University of California Berkeley, Berkeley, CA, USA.
- Children's Environmental Health Center, Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Oakland, CA, USA.
| | - Mark D Miller
- Western States Pediatric Environmental Health Specialty Unit, University of California San Francisco, San Francisco, CA, USA
- Division of Occupational and Environmental Medicine, University of California San Francisco, San Francisco, CA, USA
- Children's Environmental Health Center, Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Oakland, CA, USA
| | - John R Balmes
- Western States Pediatric Environmental Health Specialty Unit, University of California San Francisco, San Francisco, CA, USA
- Division of Occupational and Environmental Medicine, University of California San Francisco, San Francisco, CA, USA
- Division of Environmental Health Sciences, School of Public Health, University of California Berkeley, Berkeley, CA, USA
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Guha S, Herman A, Carr IA, Porter D, Natu R, Berman S, Myers MR. Comprehensive characterization of protective face coverings made from household fabrics. PLoS One 2021; 16:e0244626. [PMID: 33439878 PMCID: PMC7806137 DOI: 10.1371/journal.pone.0244626] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/15/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Face coverings constitute an important strategy for containing pandemics, such as COVID-19. Infection from airborne respiratory viruses including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can occur in at least three modes; tiny and/or dried aerosols (typically < 1.0 μm) generated through multiple mechanisms including talking, breathing, singing, large droplets (> 0.5 μm) generated during coughing and sneezing, and macro drops transmitted via fomites. While there is a growing number of studies looking at the performance of household materials against some of these situations, to date, there has not been any systematic characterization of household materials against all three modes. METHODS A three-step methodology was developed and used to characterize the performance of 21 different household materials with various material compositions (e.g. cotton, polyester, polypropylene, cellulose and blends) using submicron sodium chloride aerosols, water droplets, and mucous mimicking macro droplets over an aerosol-droplet size range of ~ 20 nm to 0.6 cm. RESULTS Except for one thousand-thread-count cotton, most single-layered materials had filtration efficiencies < 20% for sub-micron solid aerosols. However, several of these materials stopped > 80% of larger droplets, even at sneeze-velocities of up to 1700 cm/s. Three or four layers of the same material, or combination materials, would be required to stop macro droplets from permeating out or into the face covering. Such materials can also be boiled for reuse. CONCLUSION Four layers of loosely knit or woven fabrics independent of the composition (e.g. cotton, polyester, nylon or blends) are likely to be effective source controls. One layer of tightly woven fabrics combined with multiple layers of loosely knit or woven fabrics in addition to being source controls can have sub-micron filtration efficiencies > 40% and may offer some protection to the wearer. However, the pressure drop across such fabrics can be high (> 100 Pa).
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Affiliation(s)
- Suvajyoti Guha
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, United States of America
| | - Alexander Herman
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, United States of America
| | - Ian A. Carr
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, United States of America
| | - Daniel Porter
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, United States of America
| | - Rucha Natu
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, United States of America
| | - Shayna Berman
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, United States of America
| | - Matthew R. Myers
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, United States of America
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Tcharkhtchi A, Abbasnezhad N, Zarbini Seydani M, Zirak N, Farzaneh S, Shirinbayan M. An overview of filtration efficiency through the masks: Mechanisms of the aerosols penetration. Bioact Mater 2021; 6:106-122. [PMID: 32817918 PMCID: PMC7426537 DOI: 10.1016/j.bioactmat.2020.08.002] [Citation(s) in RCA: 155] [Impact Index Per Article: 51.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/01/2020] [Accepted: 08/02/2020] [Indexed: 12/12/2022] Open
Abstract
The masks have always been mentioned as an effective tool against environmental threats. They are considered as protective equipment to preserve the respiratory system against the non-desirable air droplets and aerosols such as the viral or pollution particles. The aerosols can be pollution existence in the air, or the infectious airborne viruses initiated from the sneezing, coughing of the infected people. The filtration efficiency of the different masks against these aerosols are not the same, as the particles have different sizes, shapes, and properties. Therefore, the challenge is to fabricate the filtration masks with higher efficiency to decrease the penetration percentage at the nastiest conditions. To achieve this concept, knowledge about the mechanisms of the penetration of the aerosols through the masks at different effective environmental conditions is necessary. In this paper, the literature about the different kinds of face masks and respiratory masks, common cases of their application, and the advantages and disadvantages of them in this regard have been reviewed. Moreover, the related mechanisms of the penetration of the aerosols through the masks are discussed. The environmental conditions affecting the penetration as well as the quality of the fabrication are studied. Finally, special attention was given to the numerical simulation related to the different existing mechanisms.
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Affiliation(s)
- A. Tcharkhtchi
- Arts et Metiers Institute of Technology, CNAM, PIMM, HESAM University, F-75013, Paris, France
| | - N. Abbasnezhad
- Arts et Metiers Institute of Technology, CNAM, PIMM, HESAM University, F-75013, Paris, France
- Arts et Metiers Institute of Technology, CNAM, LIFSE, HESAM University, F-75013, Paris, France
| | - M. Zarbini Seydani
- Arts et Metiers Institute of Technology, CNAM, LIFSE, HESAM University, F-75013, Paris, France
| | - N. Zirak
- Arts et Metiers Institute of Technology, CNAM, LIFSE, HESAM University, F-75013, Paris, France
| | - S. Farzaneh
- P4Tech, 23 Rue du 8 Mai 1945, 94470, Boissy Saint Leger, France
| | - M. Shirinbayan
- Arts et Metiers Institute of Technology, CNAM, PIMM, HESAM University, F-75013, Paris, France
- Arts et Metiers Institute of Technology, CNAM, LIFSE, HESAM University, F-75013, Paris, France
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Carr IA, Hariharan P, Guha S. Letter to the Editor Regarding Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks. ACS NANO 2020; 14:10754-10755. [PMID: 32961638 DOI: 10.1021/acsnano.0c04482] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Affiliation(s)
- Ian A Carr
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Prasanna Hariharan
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Suvajyoti Guha
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States
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Worden L, Wannier R, Blumberg S, Ge AY, Rutherford GW, Porco TC. Estimation of effects of contact tracing and mask adoption on COVID-19 transmission in San Francisco: a modeling study. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2020:2020.06.09.20125831. [PMID: 32577672 PMCID: PMC7302226 DOI: 10.1101/2020.06.09.20125831] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The current COVID-19 pandemic has spurred concern about what interventions may be effective at reducing transmission. The city and county of San Francisco imposed a shelter-in-place order in March 2020, followed by use of a contact tracing program and a policy requiring use of cloth face masks. We used statistical estimation and simulation to estimate the effectiveness of these interventions in San Francisco. We estimated that self-isolation and other practices beginning at the time of San Francisco's shelter-in-place order reduced the effective reproduction number of COVID-19 by 35.4% (95% CI, -20.1%-81.4%). We estimated the effect of contact tracing on the effective reproduction number to be a reduction of approximately 44% times the fraction of cases that are detected, which may be modest if the detection rate is low. We estimated the impact of cloth mask adoption on reproduction number to be approximately 8.6%, and note that the benefit of mask adoption may be substantially greater for essential workers and other vulnerable populations, residents return to circulating outside the home more often. We estimated the effect of those interventions on incidence by simulating counterfactual scenarios in which contact tracing was not adopted, cloth masks were not adopted, and neither contact tracing nor cloth masks was adopted, and found increases in case counts that were modest, but relatively larger than the effects on reproduction numbers. These estimates and model results suggest that testing coverage and timing of testing and contact tracing may be important, and that modest effects on reproduction numbers can nonetheless cause substantial effects on case counts over time.
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Affiliation(s)
- Lee Worden
- Francis I. Proctor Foundation, University of California, San Francisco, CA, USA
| | - Rae Wannier
- Francis I. Proctor Foundation, University of California, San Francisco, CA, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
| | - Seth Blumberg
- Francis I. Proctor Foundation, University of California, San Francisco, CA, USA
| | - Alex Y Ge
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - George W Rutherford
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
| | - Travis C Porco
- Francis I. Proctor Foundation, University of California, San Francisco, CA, USA
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
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Goh DYT, Mun MW, Lee WLJ, Teoh OH, Rajgor DD. A randomised clinical trial to evaluate the safety, fit, comfort of a novel N95 mask in children. Sci Rep 2019; 9:18952. [PMID: 31831801 PMCID: PMC6908682 DOI: 10.1038/s41598-019-55451-w] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 11/20/2019] [Indexed: 01/08/2023] Open
Abstract
Children are more vulnerable to the risks of air pollution, including susceptibility to acquiring chronic diseases in their developing lungs. Despite these, there are no specific masks designed for and tested in children that are available to protect our young from the common particulate air pollutants today. We evaluated safety, fit and comfort of a specially designed paediatric N95 mask with an optional micro ventilator (micro fan, MF) in healthy children aged 7-14 years, in a randomized, two-period crossover design. The subjects' cardiorespiratory physiological measurements were assessed in different states of physical activity under different interventions (mask without and with MF). A total of 106 subjects were recruited between July-August 2016. The use of the mask without MF increased the End-Tidal CO2 (ETCO2) and Fractional concentration of Inspired CO2 (FICO2) at rest and on mild exertion, as expected. The use of the mask with MF brought FICO2 levels comparably closer to baseline levels without the mask for both activities. The mask, with or without the MF, was found to be well fitting, comfortable and safe for use in children at rest and on mild exertion. The N95 mask tested offers a promising start for more studies in the paediatric population.
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Affiliation(s)
- Daniel Yam Thiam Goh
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
- Khoo Teck Puat-National University Children's Medical Institute, National University Health System, Singapore, Singapore.
| | | | | | - Oon Hoe Teoh
- Department of Paediatrics, KK Women's and Children's Hospital, Singapore, Singapore
| | - Dimple D Rajgor
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Khoo Teck Puat-National University Children's Medical Institute, National University Health System, Singapore, Singapore
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Myers MR, Hariharan P, Guha S, Yan J. A mathematical model for assessing the effectiveness of protective devices in reducing risk of infection by inhalable droplets. MATHEMATICAL MEDICINE AND BIOLOGY-A JOURNAL OF THE IMA 2018; 35:1-23. [PMID: 27780877 DOI: 10.1093/imammb/dqw018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 09/13/2016] [Indexed: 11/13/2022]
Abstract
Respiratory protective devices (RPDs) are critical for reducing the spread of infection via inhalable droplets. In determining the type of RPD to deploy, it is important to know the reduction in the infection rate that the RPD enables for the given pathogen and population. This paper extends a previously developed susceptible-infected-recovered (SIR) epidemic model to analyse the effect of a protection strategy. An approximate solution to the modified SIR equations, which compares well with a full numerical solution to the equations, was used to derive a simple threshold equation for predicting when growth of the infected population will occur for a given protection strategy. The threshold equation is cast in terms of a generalized reproduction number, which contains the characteristics of the RPDs deployed by the susceptible and infected populations, as well as the degree of compliance in wearing the equipment by both populations. An example calculation showed that with 50% of the susceptible population deploying RPDs that transmit 15% of pathogens, and an unprotected infected population, an otherwise growing infection rate can be converted to one that decays. When the infected population deploys RPDs, the transmission rate for the RPDs worn by the susceptible population can be higher.
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Affiliation(s)
- Matthew R Myers
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD, USA
| | - Prasanna Hariharan
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD, USA
| | - Suvajyoti Guha
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD, USA
| | - Jing Yan
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD, USA.,Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD, USA
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Morrison TM, Pathmanathan P, Adwan M, Margerrison E. Advancing Regulatory Science With Computational Modeling for Medical Devices at the FDA's Office of Science and Engineering Laboratories. Front Med (Lausanne) 2018; 5:241. [PMID: 30356350 PMCID: PMC6167449 DOI: 10.3389/fmed.2018.00241] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/08/2018] [Indexed: 12/29/2022] Open
Abstract
Protecting and promoting public health is the mission of the U.S. Food and Drug Administration (FDA). FDA's Center for Devices and Radiological Health (CDRH), which regulates medical devices marketed in the U.S., envisions itself as the world's leader in medical device innovation and regulatory science-the development of new methods, standards, and approaches to assess the safety, efficacy, quality, and performance of medical devices. Traditionally, bench testing, animal studies, and clinical trials have been the main sources of evidence for getting medical devices on the market in the U.S. In recent years, however, computational modeling has become an increasingly powerful tool for evaluating medical devices, complementing bench, animal and clinical methods. Moreover, computational modeling methods are increasingly being used within software platforms, serving as clinical decision support tools, and are being embedded in medical devices. Because of its reach and huge potential, computational modeling has been identified as a priority by CDRH, and indeed by FDA's leadership. Therefore, the Office of Science and Engineering Laboratories (OSEL)-the research arm of CDRH-has committed significant resources to transforming computational modeling from a valuable scientific tool to a valuable regulatory tool, and developing mechanisms to rely more on digital evidence in place of other evidence. This article introduces the role of computational modeling for medical devices, describes OSEL's ongoing research, and overviews how evidence from computational modeling (i.e., digital evidence) has been used in regulatory submissions by industry to CDRH in recent years. It concludes by discussing the potential future role for computational modeling and digital evidence in medical devices.
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Affiliation(s)
- Tina M. Morrison
- Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, United States
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