Operating theatre airflow can be measured using pulsed lasers (particle image velocimetry) but the process is difficult to do in 3D. Cup, vane or hot wire anemometers provide only 2D information. 3D measurements enable better understanding of airflow. We used a Windmaster ultrasound 3D anemometer (Skyview systems), which uses three ultrasound transmitters to measure velocity in XYZ planes, with a sampling rate of 32 Hz. Post processing was done using MATLAB. An operating theatre with an Howorth Exflow canopy was studied. Equipment, including lights, was moved. A 50 cm grid was marked, and measurements were made at intervals up to the ceiling. Door opening was observed within the clean zone and the peripheral zone, next to the door and on the opposite side of the room. Anaesthetic screens were studied during operating. Airflow was visualised initially using video of smoke puffs and subsequently measured using the aeronometer.Introduction
Patients/Materials & Methods
