Bacteria-carrying particles diffusion in the operating room due to the interaction between human thermal plume and ventilation systems: An experimental-numerical simulation study

During surgery, the release of bacterial-carrying particles (BCPs) by surgeons is one of the major pollution sources in operating rooms (ORs), which may cause surgical site infection (SSIs) or health problems. The human thermal plume emitted by the human body may affect the airflow in the surgical micro-environment, leading to the further spread of BCPs. Therefore, this paper aimed to evaluate and compare the diffusion of human thermal plume and BCPs under the design conditions of four ventilation systems (vertical laminar airflow ventilation (VLAF1), horizontal laminar airflow ventilation (HLAF), vertical laminar airflow ventilation (VLAF2), and temperature-controlled airflow ventilation (TAF)). The experiments of airspeed measurements and biological particle emission were carried out in a standard vertical laminar ventilation operating room. Computational fluid dynamics (CFD) was used to extend the investigation of the different ventilation systems. In summary, both the VLAF and TAF systems were able to interact effectively with the human thermal plume, and the TAF ventilation system was superior to the other three systems in reducing BCPs levels in the air of the operating room. The TAF system was able to control the BCPs concentration in the surgical area to 20 CFU/m(3). The interaction between human thermal plume and ventilation plays an important role in the clearance of BCPs in the operating room, so it is significant to systematically compare the performance of different ventilation systems. (C) 2022 Elsevier B.V. All rights reserved.