Analysis of air and airborne particles movements in a hospital operating theater

Abstract

In this study a computational fluid dynamics (CFD) method was used to develop a validated model of a hospital operating theater. The model was employed to perform simulation to predict the distribution of airflow and movement of the airborne particles inside the operating theater at a steady-state condition. The airborne particles were modeled as discrete particles which were released from the exposed body surface of the surgical staffs at a rate of 10 CFU/s. The effect of laminar inlet air flow velocity on the airborne particles concentration around the operating table was examined. It was found that the air flows straight downward from the air-conditioning diffuser towards the middle of the operating table. However, the existence of the medical lamp causes a vortex air flow condition below it. Air also penetrates the ultra-clean area on the opposite side of the operating table. The airborne particles are washed away from the vicinity of the operating table by the air flow. This is more effective when the supply air flow velocity is high. At low air flow velocity, some particles appear to penetrate into the ultra-clean area near the edges of the operating table. At higher air flow velocity, the airborne particles seem to be more effectively washed away from this region. High concentration of airborne particles occurs underneath the medical lamp due to vortices created by the air flow. Higher air flow velocity increases the level of particles concentration in this area.