Characteristics of airflow distribution in the operating micro-environment during surgical procedures based on the thermal plume effect of lighting

In the operating room (OR), the thermal plume generated by lighting is prone to forming vortex airflow regions in the micro-environment during surgical procedures, thereby increasing the risk of surgical site infection. This study investigated the airflow distribution in the micro-environment within the OR. A coupled model of vertical laminar flow and lighting thermal plume interactions was established. The lighting height, angle and heat flux density that could influence airflow patterns in the operating micro-environment were analysed. The results indicate that compared to the scenario without heat generation from the lights, the presence of a thermal plume could significantly reduce air velocity within the operating micro-environment ( X = –0.9 to 0.9 m), decreasing by ∼0.1 m/s (a 66% decrease). Furthermore, as the lighting height, the angle and the heat flux density were increased, the air velocity in the operating micro-environment was reduced markedly. The vortex position shifted upwards and its lateral coverage area expanded. The impact of lighting parameters varied across the Y and Z directions. For the Y -direction, the height exerted the greatest influence (57.1%), followed by heat flux density (33.8%), but the angle produced less impact (9.1%). For the Z -direction, the heat flux density was the dominant factor (76.2%), with the angle producing a 15.9% rise in influence and the height by a comparatively minor 7.9%. These findings have provided theoretical support for the rational layout of lighting in vertical unidirectional airflow ORs.