Numerical Study of the Influence of Bedside Curtains on Human Exhaled Contaminants Distribution in a Two-bed Ward

Abstract

Bedside curtains are widely used in multi-bed wards to protect the privacy of patients. However, it may change the distribution of airflow and lead to cross infection. A numerical approach is applied to investigate contaminant distribution in a two-bed ward with downward ventilation. Tracer gas such as CO2 is applied to simulate the exhaled contaminants by two lying patients. The contaminant concentration distributions with and without bedside curtains are compared. The results show that bedside curtains have great impacts on the airflow throughout the ward, which leads to a significant difference in the trajectory of expiratory flow between patients. Without curtains, the supply air can reach almost all the ward except the aera bed 1. Curtains mounted without grille almost completely block the airflow to bed 1, most of the airflow along with the continuous air supply of the whole ward without passing through bed 1, while the exhaled flow of patient 2 is blocked by the curtain, which cannot be directly returned to the outlet, but is affected by the eddy current caused by fresh air and spread to the end of bed 2. The expiratory airflow of patient 1 will also spread to the whole ward, which will lead to cross-infection. Most of the supply air can pass through the grille on the upper part of the curtain to reach the upper space of bed 1, and a small part of the airflow is blocked and bounced by the curtain. The exhaled flow of patient 2 follows the bounced air back to the faces of patient 2, and then follows the supply air throughout the whole ward. Expiratory airflow of patient 1 moves upward at first and then spread to the whole ward along with the supply airflow. The study can provide a reference for wards to construct a healthy indoor environment.

Keywords

• contaminant distribution
• exhaled contaminants
• numerical simulation
• cross infection
• ward