Experimental and numerical evaluation of a new visor concept with aerodynamic sealing to protect medical professionals from contaminated droplets and aerosols

The fast spreading of the SARS-CoV-2 virus led to a significant increase in the demand for personal protective equipment (PPE). Healthcare professionals, mainly dentists, work near the patients, increasing their risk of infection. This paper investigates the effectiveness of an air-curtain sealing effect in a newly designed visor developed to reduce the risk of contracting a respiratory infection. This PPE was developed by computational fluid dynamics (CFD) modeling. CFD results show that the aerodynamic sealing in this PPE device effectively protects the user's face by 43% from a contaminated environment. The experiments considered two different tests: one using a tracer gas (CO2) to simulate a gaseous contaminant inside and outside the PPE face shield and a second test using smoke to simulate aerosol transport and evaluate the PPE efficiency. The particle concentration within the aerodynamically sealed PPE was evaluated and compared with the protection efficiency of other PPE. Results show similar protection levels for particles in the 1-5 mu m range between the prototype and a KN95 respirator. The combined use of this novel PPE with aerodynamic sealing and a physical mask (KN95 or surgical) produced protection efficiency values within the range of 57%-70% for particles greater than 0.5 mu m. This study reveals the potential of using an air curtain combined with a face shield to reduce the risks from contaminated environments.

Automated summary

This paper investigates the effectiveness of a newly designed PPE with an air-curtain sealing effect in reducing the risk of respiratory infection. The computational fluid dynamics modeling and experiments show that this PPE effectively protects the user's face by 43% from a contaminated environment. The study also reveals the potential of combining this novel PPE with a physical mask to further reduce the risks from contaminated environments.