Vahid Anwari1,2, William C K Ng3,4,5, Arnaud Romeo Mbadjeu Hondjeu4, Zixuan Xiao6, Edem Afenu7,8, Jessica Trac8, Kate Kazlovich2,9, Joshua Hiansen2, Azad Mashari2,3,4. 1. Joint Department of Medical Imaging, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada. 2. The Lynn and Arnold Irwin Advanced Perioperative Imaging Lab, Department of Anesthesiology and Pain Management, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada. 3. Department of Anesthesiology and Pain Medicine, University of Toronto, Toronto, Ontario, Canada. 4. Department of Anesthesiology and Pain Management, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada. 5. Department of Anaesthesia and Pain Management, The Hospital for Sick Children, Toronto, Ontario, Canada. 6. Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada. 7. School of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada. 8. Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada. 9. Institute of Biomaterials and Biomedical Engineering, University of Toronto, Ontario, Canada.
Abstract
INTRODUCTION: The COVID-19 pandemic has led to widespread shortages of N95 respirators and other personal protective equipment (PPE). An effective, reusable, locally-manufactured respirator can mitigate this problem. We describe the development, manufacture, and preliminary testing of an open-hardware-licensed device, the "simple silicone mask" (SSM). METHODS: A multidisciplinary team developed a reusable silicone half facepiece respirator over 9 prototype iterations. The manufacturing process consisted of 3D printing and silicone casting. Prototypes were assessed for comfort and breathability. Filtration was assessed by user seal checks and quantitative fit-testing according to CSA Z94.4-18. RESULTS: The respirator originally included a cartridge for holding filter material; this was modified to connect to standard heat-moisture exchange (HME) filters (N95 or greater) after the cartridge showed poor filtration performance due to flow acceleration around the filter edges, which was exacerbated by high filter resistance. All 8 HME-based iterations provided an adequate seal by user seal checks and achieved a pass rate of 87.5% (N = 8) on quantitative testing, with all failures occurring in the first iteration. The overall median fit-factor was 1662 (100 = pass). Estimated unit cost for a production run of 1000 using distributed manufacturing techniques is CAD $15 in materials and 20 minutes of labor. CONCLUSION: Small-scale manufacturing of an effective, reusable N95 respirator during a pandemic is feasible and cost-effective. Required quantities of reusables are more predictable and less vulnerable to supply chain disruption than disposables. With further evaluation, such devices may be an alternative to disposable respirators during public health emergencies. The respirator described above is an investigational device and requires further evaluation and regulatory requirements before clinical deployment. The authors and affiliates do not endorse the use of this device at present.
INTRODUCTION: The COVID-19 pandemic has led to widespread shortages of N95 respirators and other personal protective equipment (PPE). An effective, reusable, locally-manufactured respirator can mitigate this problem. We describe the development, manufacture, and preliminary testing of an open-hardware-licensed device, the "simple silicone mask" (SSM). METHODS: A multidisciplinary team developed a reusable silicone half facepiece respirator over 9 prototype iterations. The manufacturing process consisted of 3D printing and silicone casting. Prototypes were assessed for comfort and breathability. Filtration was assessed by user seal checks and quantitative fit-testing according to CSA Z94.4-18. RESULTS: The respirator originally included a cartridge for holding filter material; this was modified to connect to standard heat-moisture exchange (HME) filters (N95 or greater) after the cartridge showed poor filtration performance due to flow acceleration around the filter edges, which was exacerbated by high filter resistance. All 8 HME-based iterations provided an adequate seal by user seal checks and achieved a pass rate of 87.5% (N = 8) on quantitative testing, with all failures occurring in the first iteration. The overall median fit-factor was 1662 (100 = pass). Estimated unit cost for a production run of 1000 using distributed manufacturing techniques is CAD $15 in materials and 20 minutes of labor. CONCLUSION: Small-scale manufacturing of an effective, reusable N95 respirator during a pandemic is feasible and cost-effective. Required quantities of reusables are more predictable and less vulnerable to supply chain disruption than disposables. With further evaluation, such devices may be an alternative to disposable respirators during public health emergencies. The respirator described above is an investigational device and requires further evaluation and regulatory requirements before clinical deployment. The authors and affiliates do not endorse the use of this device at present.
Authors: Anita Patel; Maryann M D'Alessandro; Karen J Ireland; W Greg Burel; Elaine B Wencil; Sonja A Rasmussen Journal: Health Secur Date: 2017 May/Jun
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Authors: Stella E Hines; Clayton Brown; Marc Oliver; Patricia Gucer; Melissa Frisch; Regina Hogan; Tracy Roth; James Chang; Melissa McDiarmid Journal: Am J Infect Control Date: 2019-01-10 Impact factor: 2.918
Authors: William C K Ng; Arnaud Romeo Mbadjeu Hondjeu; Andrew Syrett; Rebecca Caragata; Dmitry Rozenberg; Zixuan Xiao; Vahid Anwari; Jessica Trac; Azad Mashari Journal: PLoS One Date: 2020-11-13 Impact factor: 3.240
Authors: Ahmed M S Ibrahim; Rod R Jose; Amr N Rabie; Theodore L Gerstle; Bernard T Lee; Samuel J Lin Journal: Plast Reconstr Surg Glob Open Date: 2015-08-10