Flat-pack, rapid production powered air purifying respirators for Low-Resource Settings amid the SARS-CoV-2 pandemic

Abstract

Healthcare workers are at high risk of catching SARS-CoV-2 because of their regular interaction with patients with the disease. In low-resource settings, the ratio of healthcare workers to the whole population is lower than in high income countries, and there is often limited access to personal protective equipment (PPE). Illness or death of healthcare workers will, therefore, have a disproportionate impact in these settings, so it is particularly important to find ways to protect them. To protect against airborne infection in healthcare settings, PPE recommendations typically include filtering facemask respirators or powered air purifying respirators (PAPR). The former, passively filter inhaled air. They are small, noiseless and do not require a power supply, but they are single-use, presenting manufacturing and supply issues. Fit testing is crucial, and many users find them difficult to tolerate, due to breathing resistance and elevated humidity. There is also the potential for contamination due to the exposed face. PAPRs are re-usable devices that may last for months and provide airflow through a filter from a battery-powered blower unit to a hood or helmet which covers the face. This creates a positive pressure in the hood or helmet that enables the wearer to breathe filtered air easily, without requiring an air-tight fit needed for standard face masks. This is reported to be more comfortable and provides better protection for the face from droplets and splashes, and infection by self-contact with the hands. PAPRs have typically been expensive, bulky and not readily available or easy to ship to low-resource settings. Although the design presented here has not been through any form of regulatory approval, the aim of this paper is to share ideas and offer possible solutions to other groups around the World who may be thinking of manufacturing a low-cost, reusable PAPR. The design is novel because it uses readily available materials, scalable manufacturing processes, and it may be shipped flat-packed and easily assembled. This offers an option for manufacturing in low-resource settings and for shipping in bulk. This paper provides the CAD designs that can be fabricated using a laser cutter.