TRANSPORT OF SURGICALLY PRODUCED AEROSOLS IN AN OPERATING-ROOM

The particle transport characteristics of two ventilation configuratio ns commonly used in hospital operating rooms (ORs), cross-flow and imp inging-flow ventilation, were investigated. The computational fluid dy namics software FLUENT was used to simulate turbulent airflow with mix ed convection in a three-dimensional, rectangular OR. Two OR personnel , a patient, OR spotlights, an anesthetics cart, and an operating tabl e were represented in the room. Heat loads from the personnel, patient , and lights affected the airflow through buoyancy. Particles produced at the operation site with various sizes and initial conditions were tracked through the room. A stochastic model was used to include the r andom effects of turbulence on particle trajectories, Simulation resul ts show that heat loads from the personnel, patient, and OR spotlights had an important effect on the airflow through natural convection. Pa rticle trajectories were influenced greatly by the flow field structur e, particle launch position, and turbulence in the flow, and somewhat by particle size. However, particle paths were insensitive to the laun ch velocity. Virtually identical trajectories were obtained for partic les with launch velocities ranging from 0 to 1 m/sec in magnitude. Cha nges in ventilation configuration dramatically affected particle trans port. The cross-flow ventilation configuration performed better, based on the criteria of removing particles from the breathing zone of room occupants. Proper flow field design and contaminant source placement can be used to control particle transport. Numerical simulations allow quick and inexpensive comparisons between room designs and provide de tails about airflow and contaminant transport.