Evaluation of infection risk by coughed air in hospital measurement of infection risk using the human cough simulation machine in a medical examination room

The objective of this research is to evaluate the infection risk by the aerosol dispersion due to human cough in a medical examination room. The experiments were conducted in a full-scale test room simulated as a medical examination room. Two types of manikins were employed. One was a "Coughing Manikin," which could simulate human cough airflow using carbon dioxide (CO₂) as a tracer gas. The other was a "Thermal Manikin," which was used as a medical doctor. Eleven conditions were examined by varying the manikin positions, airflow patterns using a push-pull ventilation system (PPVS), and other conditions. For the evaluation of the infection risk, both CO₂ concentration and the capture efficiency of CO₂ were used. It was concluded that the PPVS influenced the decrease in the infection risk depending on the CO₂ concentration and the capture efficiency. Further, it was revealed that the PPVS arrangement was an important concern.