Frontline medical workers put themselves at risk during a pandemic to deliver critical health care and save lives. Personal protective equipment (PPE) such as gloves, gowns, and face shields can reduce the risk of infection. To prevent contamination through airborne droplets, healthcare workers can employ an air-purifying respirator to push filtered air into their face shield or hood.

Workers at Austin Health performing high-risk aerosol-generating procedures opted to use air-purifying respirators together with face shields and an impermeable gown and hood. The process for removing and cleaning PPE carries the risk of infection, too – donning a gown over the first layer of PPE provides some additional protection during doffing and cleaning. A technical shortcoming soon became apparent with this method of protecting healthcare workers; the respirator intake fan caught the top-layer gown, blocking airflow and obstructing the particle filter.

3D model courtesy of NIF Facility Fellow Mr Rob Williams

Enter, the NCRIS-enabled facilities and expertise at the University of Melbourne NIF Node. A clinical-academic collaboration was initiated to engineer a solution allowing workers to use the PPE as intended. NIF Facility Fellow Mr Rob Williams of the Melbourne Brain Centre imaged the respirator’s filter and prefilter cap using a Biograph128 mCT. A 3D rendered model was then created for the Melbourne School of Design, where design engineers produced virtual prototypes for filter guards. The final design, an insertable cage to be fitted into the prefilter cap, was 3D-printed from polylactic acid filament. The team showed, using a pneumotachograph, that airflow was preserved by displacing the obstructing material. The printed filter guards are easy to use, scalable, cheap, and readily deployable – notably, they have been adopted, allowing an extra layer of protection for healthcare workers at risk due to aerosolised infections such as COVID-19.

For more information, please contact Mr Rob Williams.