ArticleBMC biomedical engineering2021
3D Printed frames to enable reuse and improve the fit of N95 and KN95 respirators.
Article in BMC biomedical engineering, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 17 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
17 citing papers in PubMed, 1 synthesis or guideline pooled it, 25 citations in OpenAlex.
- A systematic review of fit improvement strategies for respirators: lessons learned from the COVID-19 pandemic.BMC public health · 2025Pooled it
- Effect of UV-C Radiation on 3D Printed ABS-PC Polymers.Polymers · 2023Article
- Challenges and future opportunities to unlock the critical supply chain of personal and protective equipment (PPE) encompassing decontamination and reuse under emergency use authorization (EUA) conditions during the COVID-19 pandemic: Through a reflective circularity and sustainability lens.The Science of the total environment · 2023Review
- Improving the fit of filtering facepiece respirators.British dental journal · 2022Article
- Effectiveness of a 3D-printed mask fitter in an Ophthalmology setting during COVID-19.Canadian journal of ophthalmology. Journal canadien d'ophtalmologie · 2022Article
- The personal protective equipment fabricated via 3D printing technology during COVID-19.Annals of 3D printed medicine · 2022Article
- Masks for COVID-19.Advanced science (Weinheim, Baden-Wurttemberg, Germany) · 2022Review
- Review of the Effect of Continuous Use and Limited Reuse of N95 Respirators on Respirator Fit.Journal of the International Society for Respiratory Protection · 2022Article
- Article
- Assessing the filtration efficiency and regulatory status of N95s and nontraditional filtering face-piece respirators available during the COVID-19 pandemic.BMC infectious diseases · 2021Article
- Use of 3D printing to support COVID-19 medical supply shortages: a review.Journal of 3D printing in medicine · 2021Review
- De novo Powered Air-Purifying Respirator Design and Fabrication for Pandemic Response.medRxiv : the preprint server for health sciences · 2021Article
- A Crisis-Responsive Framework for Medical Device Development Applied to the COVID-19 Pandemic.Frontiers in digital health · 2021Article
- Analysis of SteraMist ionized hydrogen peroxide technology in the sterilization of N95 respirators and other PPE.Scientific reports · 2021Article
- De Novo Powered Air-Purifying Respirator Design and Fabrication for Pandemic Response.Frontiers in bioengineering and biotechnology · 2021Article
- A position statement and practical guide to the use of particulate filtering facepiece respirators (N95, FFP2, or equivalent) for South African health workers exposed to respiratory pathogens includingAfrican journal of thoracic and critical care medicine · 2021Review
- Decontamination and Reuse of N95 Filtering Facepiece Respirators: Where Do We Stand?Anesthesia and analgesia · 2021Review
Corrections and comments
- Update of
Authors and funding
22 authors at 3 institutions in 1 country.
Funding
Abstract
backgroundIn response to supply shortages caused by the COVID-19 pandemic, N95 filtering facepiece respirators (FFRs or "masks"), which are typically single-use devices in healthcare settings, are routinely being used for prolonged periods and in some cases decontaminated under "reuse" and "extended use" policies. However, the reusability of N95 masks is limited by degradation of fit. Possible substitutes, such as KN95 masks meeting Chinese standards, frequently fail fit testing even when new. The purpose of this study was to develop an inexpensive frame for damaged and poorly fitting masks using readily available materials and 3D printing.
resultsAn iterative design process yielded a mask frame consisting of two 3D printed side pieces, malleable wire links that users press against their face, and cut lengths of elastic material that go around the head to hold the frame and mask in place. Volunteers (n = 45; average BMI = 25.4), underwent qualitative fit testing with and without mask frames wearing one or more of four different brands of FFRs conforming to US N95 or Chinese KN95 standards. Masks passed qualitative fit testing in the absence of a frame at rates varying from 48 to 94 % (depending on mask model). For individuals who underwent testing using respirators with broken or defective straps, 80-100 % (average 85 %) passed fit testing with mask frames. Among individuals who failed fit testing with a KN95, ~ 50 % passed testing by using a frame.
conclusionsOur study suggests that mask frames can prolong the lifespan of N95 and KN95 masks by serving as a substitute for broken or defective bands without adversely affecting fit. Use of frames made it possible for ~ 73 % of the test population to achieve a good fit based on qualitative and quantitative testing criteria, approaching the 85-90 % success rate observed for intact N95 masks. Frames therefore represent a simple and inexpensive way of expanding access to PPE and extending their useful life. For clinicians and institutions interested in mask frames, designs and specifications are provided without restriction for use or modification. To ensure adequate performance in clinical settings, fit testing with user-specific masks and PanFab frames is required.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.