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Redmann RK, Beddingfield BJ, Spencer S, Chirichella NR, Henley JL, Hager W, Roy CJ. A Miniaturized Electrostatic Precipitator Respirator Effectively Removes Ambient SARS-CoV-2 Bioaerosols. Viruses 2022; 14:v14040765. [PMID: 35458496 PMCID: PMC9025737 DOI: 10.3390/v14040765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/23/2022] [Accepted: 03/31/2022] [Indexed: 12/04/2022] Open
Abstract
The inhalation of ambient SARS-CoV-2-containing bioaerosols leads to infection and pandemic airborne transmission in susceptible populations. Filter-based respirators effectively reduce exposure but complicate normal respiration through breathing zone pressure differentials; therefore, they are impractical for long-term use. Objectives: We tested the comparative effectiveness of a prototyped miniaturized electrostatic precipitator (mEP) on a filter-based respirator (N95) via the removal of viral bioaerosols from a simulated, inspired air stream. Methods: Each respirator was tested within a 16 L environmental chamber housed within a Class III biological safety cabinet within biosafety level 3 containment. SARS-CoV-2-containing bioaerosols were generated in the chamber, drawn by a vacuum through each respirator, and physical particle removal and viral genomic RNA were measured distal to the breathing zone of each device. Measurements and Main Results: The mEP respirator removed particles (96.5 ± 0.4%), approximating efficiencies of the N95 (96.9 ± 0.6%). The mEP respirator similarly decreased SARS-CoV-2 viral RNA (99.792%) when compared to N95 removal (99.942%), as a function of particle removal from the airstream distal to the breathing zone of each respirator. Conclusions: The mEP respirator approximated the performance of a filter-based N95 respirator for particle removal and viral RNA as a constituent of the SARS-CoV-2 bioaerosols generated for this evaluation. In practice, the mEP respirator could provide equivalent protection from ambient infectious bioaerosols as the N95 respirator without undue pressure drop to the wearer, thereby facilitating its long-term use in an unobstructed breathing configuration.
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Affiliation(s)
- Rachel K. Redmann
- Infectious Disease Aerobiology, Division of Microbiology, Tulane National Primate Research Center, Covington, LA 70433, USA; (R.K.R.); (B.J.B.); (S.S.); (N.R.C.)
| | - Brandon J. Beddingfield
- Infectious Disease Aerobiology, Division of Microbiology, Tulane National Primate Research Center, Covington, LA 70433, USA; (R.K.R.); (B.J.B.); (S.S.); (N.R.C.)
| | - Skye Spencer
- Infectious Disease Aerobiology, Division of Microbiology, Tulane National Primate Research Center, Covington, LA 70433, USA; (R.K.R.); (B.J.B.); (S.S.); (N.R.C.)
| | - Nicole R. Chirichella
- Infectious Disease Aerobiology, Division of Microbiology, Tulane National Primate Research Center, Covington, LA 70433, USA; (R.K.R.); (B.J.B.); (S.S.); (N.R.C.)
| | - Julian L. Henley
- Section of Otolaryngology, Yale-New Haven Hospital, New Haven, CT 06520, USA;
- Henley Ion, New Orleans, LA 70115, USA
| | - Wes Hager
- Phase Three Product Development, Fort Collins, CO 80526, USA;
| | - Chad J. Roy
- Infectious Disease Aerobiology, Division of Microbiology, Tulane National Primate Research Center, Covington, LA 70433, USA; (R.K.R.); (B.J.B.); (S.S.); (N.R.C.)
- Department of Microbiology and Immunology, Tulane School of Medicine, New Orleans, LA 70112, USA
- Correspondence:
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Ballard DH, Dang AJ, Kumfer BM, Weisensee PB, Meacham JM, Scott AR, Ruppert-Stroescu M, Burke BA, Morris J, Gan C, Hu J, King B, Jammalamadaka U, Sayood S, Liang S, Choudhary S, Dhanraj D, Maranhao B, Millar C, Bertroche JT, Shomer N, Woodard PK, Biswas P, Axelbaum R, Genin G, Williams BJ, Meacham K. Protection levels of N95-level respirator substitutes proposed during the COVID-19 pandemic: safety concerns and quantitative evaluation procedures. BMJ Open 2021; 11:e045557. [PMID: 34475144 PMCID: PMC8413478 DOI: 10.1136/bmjopen-2020-045557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE The COVID-19 pandemic has precipitated widespread shortages of filtering facepiece respirators (FFRs) and the creation and sharing of proposed substitutes (novel designs, repurposed materials) with limited testing against regulatory standards. We aimed to categorically test the efficacy and fit of potential N95 respirator substitutes using protocols that can be replicated in university laboratories. SETTING Academic medical centre with occupational health-supervised fit testing along with laboratory studies. PARTICIPANTS Seven adult volunteers who passed quantitative fit testing for small-sized (n=2) and regular-sized (n=5) commercial N95 respirators. METHODS Five open-source potential N95 respirator substitutes were evaluated and compared with commercial National Institute for Occupational Safety and Health (NIOSH)-approved N95 respirators as controls. Fit testing using the 7-minute standardised Occupational Safety and Health Administration fit test was performed. In addition, protocols that can be performed in university laboratories for materials testing (filtration efficiency, air resistance and fluid resistance) were developed to evaluate alternate filtration materials. RESULTS Among five open-source, improvised substitutes evaluated in this study, only one (which included a commercial elastomeric mask and commercial HEPA filter) passed a standard quantitative fit test. The four alternative materials evaluated for filtration efficiency (67%-89%) failed to meet the 95% threshold at a face velocity (7.6 cm/s) equivalent to that of a NIOSH particle filtration test for the control N95 FFR. In addition, for all but one material, the small surface area of two 3D-printed substitutes resulted in air resistance that was above the maximum in the NIOSH standard. CONCLUSIONS Testing protocols such as those described here are essential to evaluate proposed improvised respiratory protection substitutes, and our testing platform could be replicated by teams with similar cross-disciplinary research capacity. Healthcare professionals should be cautious of claims associated with improvised respirators when suggested as FFR substitutes.
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Affiliation(s)
- David H Ballard
- School of Medicine Mallinckrodt Institute of Radiology, Washington University, Saint Louis, Missouri, USA
| | - Audrey J Dang
- Department of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, Missouri, USA
| | - Benjamin M Kumfer
- Department of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, Missouri, USA
| | - Patricia B Weisensee
- Department of Mechanical Engineering & Materials Science, Washington University in St Louis, St Louis, Missouri, USA
| | - J Mark Meacham
- Department of Mechanical Engineering & Materials Science, Washington University in St Louis, St Louis, Missouri, USA
| | - Alex R Scott
- School of Medicine, Washington University in St Louis, St Louis, Missouri, USA
| | - Mary Ruppert-Stroescu
- Sam Fox School of Design and Visual Arts, Washington University in St Louis, St Louis, Missouri, USA
| | - Broc A Burke
- Department of Anesthesiology, Washington University in St Louis, St Louis, Missouri, USA
| | - Jason Morris
- School of Medicine, Washington University in St Louis, St Louis, Missouri, USA
| | - Connie Gan
- School of Medicine, Washington University in St Louis, St Louis, Missouri, USA
| | - Jesse Hu
- School of Medicine, Washington University in St Louis, St Louis, Missouri, USA
| | - Bradley King
- Department of Environmental Health & Safety, Washington University in St Louis, St Louis, Missouri, USA
| | - Udayabhanu Jammalamadaka
- School of Medicine Mallinckrodt Institute of Radiology, Washington University, Saint Louis, Missouri, USA
| | - Sena Sayood
- Division of Infectious Diseases, Washington University in St Louis, St Louis, Missouri, USA
| | - Stephen Liang
- Division of Infectious Diseases, Washington University in St Louis, St Louis, Missouri, USA
| | - Shruti Choudhary
- Department of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, Missouri, USA
| | - David Dhanraj
- Department of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, Missouri, USA
| | - Bruno Maranhao
- Department of Anesthesiology, Washington University in St Louis, St Louis, Missouri, USA
| | - Christine Millar
- Department of Anesthesiology, Memorial Hospital Belleville, St Louis, Missouri, USA
| | - J Tyler Bertroche
- Department of Otolaryngology-Head & Neck Surgery, Washington University in St Louis, St Louis, Missouri, USA
| | - Nirah Shomer
- Division of Comparative Medicine, Washington University in St Louis, St Louis, Missouri, USA
| | - Pamela K Woodard
- School of Medicine Mallinckrodt Institute of Radiology, Washington University, Saint Louis, Missouri, USA
| | - Pratim Biswas
- Department of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, Missouri, USA
| | - Richard Axelbaum
- Department of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, Missouri, USA
| | - Guy Genin
- Department of Mechanical Engineering & Materials Science, Washington University in St Louis, St Louis, Missouri, USA
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St Louis, Missouri, USA
- Bioinspired Engineering and Biomechanics Center, School of Life Sciences and Technology, Xi'an Jiaotong University, China, Xi'an, China
| | - Brent J Williams
- Department of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, Missouri, USA
| | - Kathleen Meacham
- Department of Anesthesiology, Washington University in St Louis, St Louis, Missouri, USA
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Kumar KPA, Pumera M. 3D-Printing to Mitigate COVID-19 Pandemic. ADVANCED FUNCTIONAL MATERIALS 2021; 31:2100450. [PMID: 34230824 PMCID: PMC8250363 DOI: 10.1002/adfm.202100450] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/13/2021] [Indexed: 05/08/2023]
Abstract
3D-printing technology provided numerous contributions to the health sector during the recent Coronavirus disease 2019 (COVID-19) pandemic. Several of the 3D-printed medical devices like personal protection equipment (PPE), ventilators, specimen collectors, safety accessories, and isolation wards/ chambers were printed in a short time as demands for these were rising significantly. The review discusses some of these contributions of 3D-printing that helped to protect several lives during this health emergency. By enlisting some of the significant benefits of using the 3D-printing technique during an emergency over other conventional methods, this review claims that the former opens enormous possibilities in times of serious shortage of supply and exceeding demands. This review acknowledges the collaborative approaches adopted by individuals, entrepreneurs, academicians, and companies that helped in forming a global network for delivering 3D-printed medical/non-medical components, when other supply chains were disrupted. The collaboration of the 3D-printing technology with the global health community unfolds new and significant opportunities in the future.
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Affiliation(s)
| | - Martin Pumera
- Future Energy and Innovation LaboratoryCentral European Institute of TechnologyBrno University of TechnologyPurkyňova 123Brno61200Czech Republic
- Department of Chemistry and Biochemistry3D Printing & Innovation HubMendel University in BrnoZemedelska 1Brno61300Czech Republic
- Department of Chemical and Biomolecular EngineeringYonsei University50 Yonsei‐ro, Seodaemun‐guSeoul03722Korea
- Department of Medical ResearchChina Medical University HospitalChina Medical UniversityNo. 91 Hsueh‐Shih RoadTaichung40402Taiwan
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Ballard DH, Jammalamadaka U, Meacham KW, Hoegger MJ, Burke BA, Morris JA, Scott AR, O'Connor Z, Gan C, Hu J, Tappa K, Wahl RL, Woodard PK. Quantitative Fit Tested N95 Respirator-Alternatives Generated With CT Imaging and 3D Printing: A Response to Potential Shortages During the COVID-19 Pandemic. Acad Radiol 2021; 28:158-165. [PMID: 33257256 PMCID: PMC7680062 DOI: 10.1016/j.acra.2020.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 11/15/2020] [Accepted: 11/16/2020] [Indexed: 02/06/2023]
Abstract
Rationale and Objective Three-dimensional (3D) printing allows innovative solutions for personal protective equipment, particularly in times of crisis. Our goal was to generate an N95-alternative 3D-printed respirator that passed Occupational Safety and Health Administration (OSHA)-certified quantitative fit testing during the COVID-19 pandemic. Materials and Methods 3D printed prototypes for N95 solutions were created based on the design of commercial N95 respirators. Computed tomography imaging was performed on an anthropomorphic head phantom wearing a commercially available N95 respirator and these facial contour data was used in mask prototyping. Prototypes were generated using rigid and flexible polymers. According to OSHA standards, prototypes underwent subsequent quantitative respirator fit testing on volunteers who passed fit tests on commercial N95 respirators. Results A total of 10 prototypes were 3D printed using both rigid (n = 5 designs) and flexible materials (n = 5 designs), Prototypes generated with rigid printing materials (n = 5 designs) did not pass quantitative respirator fit testing. Three of the five prototypes with flexible materials failed quantitative fit testing. The final two prototypes designs passed OSHA-certified quantitative fit tests with an overall mean fit factor of 138 (passing is over 100). Conclusion Through rapid prototyping, 3D printed N95 alternative masks were designed with topographical facial computed tomography data to create mask facial contour and passed OSHA-certified quantitative respiratory testing when flexible polymer was used. This mask design may provide an alternative to disposable N95 respirators in case of pandemic-related shortages. Furthermore, this approach may allow customization for those that would otherwise fail fit testing on standard commercial respirators.
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Duda S, Hartig S, Hagner K, Meyer L, Intriago PW, Meyer T, Wessling H. Potential risks of a widespread use of 3D printing for the manufacturing of face masks during the severe acute respiratory syndrome coronavirus 2 pandemic. JOURNAL OF 3D PRINTING IN MEDICINE 2020. [PMCID: PMC7707523 DOI: 10.2217/3dp-2020-0014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Background: In 2020, the severe acute respiratory syndrome coronavirus 2 pandemic caused serious concerns about the availability of face masks. This paper studies the technical feasibility of user-specific face mask production by 3D printing and the effectiveness of these masks. Material & methods: Six different face mask designs were produced by 3D printing and tested by subjective experimenter evaluation and using a respirator fit testing kit. Results were compared with the requirements as given for standard protective face masks. Results: None of the printed masks came anywhere near the required standards for personal protective gear. Conclusion: In spite of their euphoric presentation in the press, none of the currently advertised 3D printed mask designs are suitable as reliable personal protective equipment. The 3D printing community contributed to overcome potential supply bottlenecks for personal protective gear during the worldwide spread of the corona virus disease by providing open-source data for 3D printing of personal protective equipment. In this study, different mask designs were produced by 3D printing and subjected to a technical examination to evaluate the protective properties of these masks. In spite of their euphoric presentation in the press, none of the tested masks are suitable as reliable personal protective equipment.
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Affiliation(s)
- Sven Duda
- Department of Neurosurgery, Hospital of the German Armed Forces, Lange Strasse 38, Westerstede 26655, Germany
| | - Sascha Hartig
- Laboratory for Manufacturing Technology, Helmut Schmidt University/University of the German Armed Forces, Holstenhofweg 85, Hamburg 22043, Germany
| | - Karola Hagner
- Department for Individual and Collective Protection, Bundeswehr Research Institute for Protective Technologies & NBC Protection (WIS), Humboldtstraße 100, Munster 29633, Germany
| | - Lisa Meyer
- Department of Neurosurgery, Hospital of the German Armed Forces, Lange Strasse 38, Westerstede 26655, Germany
| | - Paula Wessling Intriago
- Department of Neurosurgery, Hospital of the German Armed Forces, Lange Strasse 38, Westerstede 26655, Germany
| | - Tobias Meyer
- Laboratory for Manufacturing Technology, Helmut Schmidt University/University of the German Armed Forces, Holstenhofweg 85, Hamburg 22043, Germany
| | - Heinrich Wessling
- Department of Neurosurgery, Hospital of the German Armed Forces, Lange Strasse 38, Westerstede 26655, Germany
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