A quantitative analysis of 3D printed face shields and masks during COVID-19 [version 1; peer review: 2 approved]
ABSTRACT: In response to shortages in personal protective equipment (PPE) during the COVID-19 pandemic, makers, community groups and manufacturers around the world utilised 3D printing to fabricate items, including face shields and face masks for healthcare workers and the broader community. In reaction to both local and global needs, numerous designs emerged and were shared online. In this paper, 37 face shields and 31 face masks suitable for fused filament fabrication were analysed from a fabrication perspective, documenting factors such as filament use, time to print and geometric qualities. 3D print times for similar designs varied by several hours, meaning some designs could be produced in higher volumes. Overall, the results show that face shields were approximately twice as fast to 3D print compared to face masks and used approximately half as much filament. Additionally, a face shield typically required 1.5 parts to be 3D printed, whereas face masks required 5 3D printed parts. However, by quantifying the print times, filament use, 3D printing costs, part dimensions, number of parts and total volume of each design, the wide variations within each product category could be tracked and evaluated. This data and objective analysis will help makers, manufacturers, regulatory bodies and researchers consolidate the 3D printing response to COVID-19 and optimise the ongoing strategy to combat supply chain shortages now and in future healthcare crises.
Project description:BACKGROUND:Anesthesia providers are at risk for contracting COVID-19 due to close patient contact, especially during shortages of personal protective equipment. We present an easy to follow and detailed protocol for producing 3D printed face shields and an effective decontamination protocol, allowing their reuse. METHODS:The University of Nebraska Medical Center (UNMC) produced face shields using a combination of 3D printing and assembly with commonly available products, and produced a simple decontamination protocol to allow their reuse. To evaluate the effectiveness of the decontamination protocol, we inoculated bacterial suspensions of E. coli and S. aureus on to the face shield components, performed the decontamination procedure, and finally swabbed and enumerated organisms onto plates that were incubated for 12-24 hours. Decontamination effectiveness was evaluated using the average log10 reduction in colony counts. RESULTS:Approximately 112 face shields were constructed and made available for use in 72 hours. These methods were successfully implemented for in-house production at UNMC and at Tripler Army Medical Center (Honolulu, Hawaii). Overall, the decontamination protocol was highly effective against both E. coli and S. aureus, achieving a ?4 log10 (99.99%) reduction in colony counts for every replicate from each component of the face shield unit. DISCUSSION:Face shields not only act as a barrier against the soiling of N95 face masks, they also serve as more effective eye protection from respiratory droplets over standard eye shields. Implementation of decontamination protocols successfully allowed face shield and N95 mask reuse, offering a higher level of protection for anesthesiology providers at the onset of the COVID-19 pandemic. CONCLUSIONS:In a time of urgent need, our protocol enabled the rapid production of face shields by individuals with little to no 3D printing experience, and provided a simple and effective decontamination protocol allowing reuse of the face shields.
Project description:BACKGROUND:Malaria vector control and research rely heavily on monitoring mosquito populations for the development of resistance to public health insecticides. One standard method for determining resistance in adult mosquito populations is the World Health Organization test (WHO bioassay). The WHO bioassay kit consists of several acrylic pieces that are assembled into a unit. Parts of the kit commonly break, reducing the capacity of insectaries to carry out resistance profiling. Since there is at present only a single supplier for the test kits, replacement parts can be hard to procure in a timely fashion. METHODS:Using computer-aided design software and widely available polylactic acid (PLA) filament as a printing material, we 3D designed and printed replacement parts for the WHO bioassay system. We conducted a comparison experiment between original WHO bioassay kits and 3D printed kits to assess congruence between results. The comparison experiment was performed on two Kenyan laboratory strains of Anopheles gambiae (s.s.), Kilifi and Mbita. Student's t-tests were used to assess significant differences between tube types. Finally, we exposed the PLA filament to common solutions used with the bioassay kit. RESULTS:We were able to design and print functional replacements for each piece of the WHO bioassay kit. Replacement parts are functionally identical to and interchangeable with original WHO bioassay parts. We note no significant difference in mortality results obtained from PLA printed tubes and WHO acrylic tubes. Additionally, we observed no degradation of PLA in response to prolonged exposure times of commonly used cleaning solutions. CONCLUSIONS:Our designs can be used to produce replacement parts for the WHO bioassay kit in any facility with a 3D printer, which are becoming increasingly widespread. 3D printing technologies can affordably and rapidly address equipment shortages and be used to develop bespoke equipment in laboratories.
Project description:Due to supply chain disruption, the COVID-19 pandemic has caused severe shortages in personal protective equipment (PPE) for health care professionals. Local fabrication based on 3D printing is one way to address this challenge, particularly in the case of simple products such as protective face shields. As a consequence, many public domain designs for face shields have become available. No clear path exists, however, for introducing a locally fabricated and unapproved product into a clinical setting. In a US health care setting, face shields are regulated by the Food and Drug Administration (FDA); similar policies exist in other countries. We describe a research protocol under which rapid iteration on an existing design, coupled with clinical feedback and real-world testing in an emergency department, allowed a face shield to be adopted by the incident command team at a major academic medical center. We describe our design and testing process and provide an overview of regulatory considerations associated with fabrication and testing of face shields and related products. All designs, materials used, testing protocols, and survey results are reported in full to facilitate the execution of similar face shield efforts in other clinical settings. Our work serves as a case study for development of a robust local response to pandemics and other health care emergencies, with implications for healthcare professionals, hospital administrators, regulatory agencies and concerned citizens.
Project description:The COVID-19 pandemic significantly increased demand for medical and protective equipment by frontline health workers, as well as the general community, causing the supply chain to stretch beyond capacity, an issue further heightened by geographical and political lockdowns. Various 3D printing technologies were quickly utilised by businesses, institutions and individuals to manufacture a range of products on-demand, close to where they were needed. This study gathered data about 91 3D printed projects initiated prior to April 1, 2020, as the virus spread globally. It found that 60% of products were for personal protective equipment, of which 62% were 3D printed face shields. Fused filament fabrication was the most common 3D print technology used, and websites were the most popular means of centralising project information. The project data provides objective, quantitative insight balanced with qualitative critical review of the broad trends, opportunities and challenges that could be used by governments, health and medical bodies, manufacturing organisations and the 3D printing community to streamline the current response, as well as plan for future crises using a distributed, flexible manufacturing approach.
Project description:Here, we report on the inexpensive fabrication of an electrospray/electrospinning setup by fused deposition modelling (FDM) 3D printing and provide the files and parameters needed to print this versatile device. Both electrospray and electrospinning technologies are widely used for pharmaceutical, healthcare and bioengineering applications. The setup was designed to be modular, thus its parts can be exchanged easily. The design provides a safe setup, ensuring that the users are not exposed to the high voltage parts of the setup. PLA, PVA, and a thermoplastic elastomer filament were used for the 3D printing. The filament cost was $100 USD and the rig was printed in 6?days. An Ultimaker 3 FDM 3D printer was used with dual print heads, and the PVA was used as a water-soluble support structure. The end part of the setup had several gas channels, allowing a uniform gas flowing against the direction of the nanoparticles/nanofibers, enhancing the drying process by enhancing the evaporation rate. The setup was tested in both electrospray and electrospinning modes successfully. Both the .sldprt and .stl files are provided for free download.
Project description:<h4>Background</h4>Due to supply chain disruption, the COVID-19 pandemic has caused severe shortages in personal protective equipment for health care professionals. Local fabrication based on 3D printing is one way to address this challenge, particularly in the case of products such as protective face shields. No clear path exists, however, for introducing a locally fabricated product into a clinical setting.<h4>Methods</h4>We describe a research protocol under Institutional Review Board supervision that allowed clinicians to participate in an iterative design process followed by real-world testing in an emergency department. All designs, materials used, testing protocols, and survey results are reported in full to facilitate similar efforts in other clinical settings.<h4>Findings</h4>Clinical testing allowed the incident command team at a major academic medical center to introduce the locally fabricated face shield into general use in a rapid but well-controlled manner. Unlike standard hospital face shields, the locally fabricated design was intended to be reusable. We discuss the design and testing process and provide an overview of regulatory considerations associated with fabrication and testing of personal protective equipment, such as face shields.<h4>Conclusions</h4>Our work serves as a case study for robust, local responses to pandemic-related disruption of medical supply chains with implications for health care professionals, hospital administrators, regulatory agencies, and concerned citizens in the COVID-19 and future health care emergencies.<h4>Funding</h4>: This work was supported by the Harvard MIT Center for Regulatory Sciences, NIH/NCI grants U54-CA225088 and T32-GM007753, and the Harvard Ludwig Center. M.-J.A. is a Friends of McGovern Graduate Fellow.
Project description:Past work has shown that particle material extrusion (fused particle fabrication (FPF)/fused granular fabrication (FGF)) has the potential for increasing the use of recycled polymers in 3D printing. This study extends this potential to high-performance (high-mechanical-strength and heat-resistant) polymers using polycarbonate (PC). Recycled PC regrind of approximately 25 mm2 was 3D printed with an open-source Gigabot X and analyzed. A temperature and nozzle velocity matrix was used to find useful printing parameters, and a print test was used to maximize the output for a two-temperature stage extruder for PC. ASTM type 4 tensile test geometries as well as ASTM-approved compression tests were used to determine the mechanical properties of PC and were compared with filament printing and the bulk virgin material. The results showed the tensile strength of parts manufactured from the recycled PC particles (64.9 MPa) were comparable to that of the commercial filament printed on desktop (62.2 MPa) and large-format (66.3 MPa) 3D printers. Three case study applications were investigated: (i) using PC as a rapid molding technology for lower melting point thermoplastics, (ii) printed parts for high temperature applications, and (iii) printed parts for high-strength applications. The results show that recycled PC particle-based 3D printing can produce high-strength and heat-resistant products at low costs.
Project description:Purpose Many commonly used mask designs are secured by elastic straps looping around the posterior auricular region. This constant pressure and friction against the skin may contribute to increased wearer pain, irritation, and discomfort. The purpose of this work is to report a modified 3D printed mask extender to alleviate discomfort and increase mask wearability by relieving posterior auricular pressure from isolation masks. Methods Our institutional review board designated this project as non-human research and exempt. As part of resourcing 3D printing laboratories along with individual 3D printers to provide resources to healthcare workers, mask extenders were printed to relieve posterior auricular pressure from individuals wearing isolation masks. The authors modifed an existing mask extender, increasing its length with accompanying peripheral rungs for isolation mask securement. 3D printing was performed with Ultimaker S5 (Ultimaker B.V.; Geldermalsen, Netherlands) and CR-10 (Creality3D; Shenzhen, China) 3D printers using polylactic acid filaments. The author’s modified extended mask extenders were printed and freely delivered to healthcare workers (physicians, nurses, technologists, and other personnel) at the authors’ institution. Results The final mask extender design was printed with the two 3D printers with a maximum 7 straps printed simultaneously on each 3D printer. Mean print times ranges from 105?min for the Ultimaker S5 printer and 150?min for the CR-10. Four hundred seventy-five mask extenders were delivered to healthcare workers at the authors’ institution, with the demand far exceeding the available supply. Conclusion We offer a modification of a 3D printed mask extender design that decreases discomfort and increases the wearability of isolation mask designs with ear loops thought to relieve posterior auricular skin pressure and ability to control strap tension. The design is simple, produced with inexpensive material (polylactic acid), and have been well-received by healthcare providers at our institution.
Project description:<h4>Rationale and objective</h4>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.<h4>Materials and methods</h4>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.<h4>Results</h4>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).<h4>Conclusion</h4>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.
Project description:The COVID-19 pandemic has disrupted the supply chain for personal protective equipment (PPE) for medical professionals, including N95-type respiratory protective masks. To address this shortage, many have looked to the agility and accessibility of additive manufacturing (AM) systems to provide a democratized, decentralized solution to producing respirators with equivalent protection for last-resort measures. However, there are concerns about the viability and safety in deploying this localized download, print, and wear strategy due to a lack of commensurate quality assurance processes. Many open-source respirator designs for AM indicate that they do not provide N95-equivalent protection (filtering 95% of SARS-CoV-2 particles) because they have either not passed aerosol generation tests or not been tested. Few studies have quantified particle transmission through respirator designs outside of the filter medium. This is concerning because several polymer-based AM processes produce porous parts, and inherent process variation between printers and materials also threaten the integrity of tolerances and seals within the printed respirator assembly. No study has isolated these failure mechanisms specifically for respirators. The goal of this paper is to measure particle transmission through printed respirators of different designs, materials, and AM processes. The authors compare the performance of printed respirators to N95 respirators and cloth masks. Respirators in this study printed using desktop- and industrial-scale fused filament fabrication processes and industrial-scale powder bed fusion processes were not sufficiently reliable for widespread distribution and local production of N95-type respiratory protection. Even while assuming a perfect seal between the respirator and the user's face, although a few respirators provided >90% efficiency at the 100-300 nm particle range, almost all printed respirators provided <60% filtration efficiency. Post-processing procedures including cleaning, sealing surfaces, and reinforcing the filter cap seal generally improved performance, but the printed respirators showed similar performance to various cloth masks. The authors further explore the process-driven aspects leading to low filtration efficiency. Although the design/printer/material combination dictates the AM respirator performance, the identified failure modes originate from system-level constraints and are therefore generalizable across multiple AM processes. Quantifying the limitations of AM in producing N95-type respiratory protective masks advances understanding of AM systems toward the development of better part and machine designs to meet the needs of reliable, functional, end-use parts.