Development of positive/negative pressure booth generating airflow for protection of medical staff from contagious respiratory pathogens.

Background: The pandemic of COVID-19 caused confusion in medical settings because of increased patient load, and caused many infections among medical staff which occurred through exposure to bio-particles discharged from patients. The risk of exposure became maximum at the examination of patients, particularly in the collection of respiratory specimens. Effective interventions to reduce the risk are needed.

Methods: A one-person booth consisting of curtain walls, frames, and fan-HEPA filter-unit (FFU) was designed. Using the airstream from/to FFU, it has dual functions as a positive/negative pressure machine to prevent pathogens in patient's cough to reach the medical staff inside/outside the booth, respectively. The curtain walls and positioning of the patient and staff were aerodynamically optimized for the best control of the airstream.

Results: The positive pressure booth is to isolate a staff inside to safely deal with a surge in the number of patients in situations like influenza pandemics. The negative pressure booth is to isolate a patient inside to protect a staff outside from dangerous contagious respiratory infectious diseases including COVID-19. A calculated airflow of the positive pressure machine efficiently pushed back bio-particles discharged from a person outside the booth. The bio-particles of a cough from a person inside the negative pressure booth was sucked into the FFU for filtration immediately after the discharge. The booth needed a short front curtain of a stair-cut shape, and a patient and a staff facing each other needed to be positioned at an angle 45° to the airstream for optimization of the airflow.

Conclusions: The booth named Barriflow would prevent the bioparticles of a patient's cough to reach the medical staff due to an aerodynamically designed airstream from the FFU and curtains surrounding it. It could be applied to cases of not only COVID-19 or influenza but also of other dangerous, contagious respiratory diseases.