Design, Manufacturing, and Testing of 3D-Printed Fittings for Helmet Continuous Positive Airway Pressure Medical Device: A Case Study in Ergonomic Optimisation

This study presents the geometrical optimisation of fitting connectors to a Continuous Positive Airway Pressure (CPAP) helmet for use with a ventilator in the treatment of acute respiratory failure. The initial design, developed in 2019 during the COVID-19 pandemic, underwent several optimisation stages. The goal was to reduce the size and weight of air supply and exhaust fittings while improving manufacturability via 3D printing. Two additive manufacturing (AM) techniques were evaluated: Fused Filament Fabrication (FFF) and Laser Powder Bed Fusion of polymers (PBF-LB/P). Experimental tests assessed the risk of microplastic particle detachment from components printed with medically approved PET-G and ABS-Medical filaments. ABS-Medical proved the most suitable, demonstrating reduced susceptibility to hairline structure formation during printing. The final optimised geometry, significantly smaller and lighter, was adapted to the selected AM processes. As a result, approximately 150 CPAP helmet fittings were produced and tested in clinical trials.