Evaluation of Respiratory Mask Fitting Using Finite Element Analysis Numerical Simulations and Experimental Pressure Measurements

Purpose: Prolonged wear of generic respiratory masks such as the N95 could provide discomfort due to poor fitting to the user face morphology and excessive tightening. This study aims to personalize the design of respiratory masks and simulate the fitting using finite element analysis. Methods: A cohort of 10 participants was recruited to evaluate the fit of a 3D respiratory mask created by scanning the face with the ARKit framework and a high-resolution 3D infrared camera. The respiratory mask pressure and seal were calculated using numerical simulations with Ansys Mechanical. A pressure map illustrates the pattern that the respiratory mask will produce on a given user’s face, to assert the desired comfort criteria. A map of the gap between the mask and the face shows the sealing capability of the mask. To ensure the consistency of the numerical results, experimental pressure measurements were also performed on the participants. Facial pressure calculation and measurement tests were performed under three levels of tightening. User’s feedback on the respiratory mask was also obtained. Results: Simulation results appeared to be lower than those obtained experimentally, so a global correction was made. Only 14% of the results obtained after correction differ by more than 1N from the experimental reference value. Conclusion: The outcome of this study could provide insights in the design of respiratory masks through face scanning technologies and numerical simulation. Moreover, it could contribute to fully customize the respiratory mask to the user’s face, for enhanced comfort and proper sealing.