Dynamic investigation on bacteria-carrying particles distribution in operating theatre under the walking impact of a scrub nurse

To reduce the threats of surgical site infections (SSIs), the ultraclean ventilation (UCV) system has been introduced into the operating theatre (OT). However, under the influence of surgical staff walking whether the UCV system can still provide sufficient protection for the surgical critical zone has rarely been quantitatively investigated. By applying the URANS method for simulating the dynamic airflow, the dynamic mesh model for describing the human walking and the modified drift-flux model for modelling the BCPs, the BCPs distributions in OT under different walking speeds of a scrub nurse were numerically investigated. It is found that the scrub nurse walking with speeds of 0.0 m/s and 0.25 m/s can marginally influence the BCPs distributions in surgical critical zone, while for scenarios considering faster walking speeds like 0.5 m/s and 1.0 m/s parts of the equipment table and the patient upper surface can be polluted, which can be ascribed to the secondary airflow in front of the walking nurse suppressing the opposite washing airflow blowing out from above the upper surface of the patient.