A full-face mask for protection against respiratory infections

Aerosols and droplets are the transmission routes of many respiratory infectious diseases. The COVID-19 management guidance recommends against the use of nebulized inhalation therapy directly in the emergency room or in an ambulance to prevent possible viral transmission. The three-dimensional printing method was used to develop an aerosol inhalation treatment mask that can potentially prevent aerosol dispersion. We conducted this utility validation study to understand the practicability of this new nebulizer mask system.

The fit test confirmed that the filter can efficiently remove small particles. The different locations of the mask had an excellent fit with a high pressure making a proper face seal usability. The full-face mask appeared to optimize filtration with pressure and is an example of materials that perform well for improvised respiratory protection using this design. The filtering effect test confirmed that the contamination of designated locations could be protected when using the mask with filters. As in the clinical safety test, a total of 18 participants (10 [55.6%] females; aged 33.1 ± 0.6 years) were included in the final analysis. There were no significant changes in SPO₂, EtCO₂, HR, SBP, DBP, and RR at the beginning, 20th, 40th, or 60th minutes of the test (all p >.05). The discomfort of wearing a mask increased slightly after time but remained within the tolerable range. The vision clarity score did not significantly change during the test. The mask also passed the breathability test.

The results of our study showed that this mask performed adequately in the fit test, the filtering test, and the clinical safety test. The application of a full-face mask with antiviral properties, together with the newly designed shape of a respirator that respects the natural curves of a human face, will facilitate the production of personal protective equipment with a highly efficient filtration system.

We conducted three independent tests in this validation study: (1) a fit test to calculate the particle number concentration and its association with potential leakage; (2) a filtering effect test to verify the mask's ability to contain aerosol spread; and (3) a clinical safety test to examine the clinical safety, comfortableness, and visual clarity of the mask.