To prevent contaminations and infections, various precautions are taken in an OR environment. Personnel wear masks and special clothing and a laminar flow of clean air is created within the sterile operating field. However, this controlled environment can easily be disturbed by the movements of personnel and medical equipment with internal cooling fans. In progress of a previous study, a special large field air flow visualization technique has been adapted to study and quantify the air flow around equipment used in the OR in real-time.
Optical distortions induced by small density gradients in flowing air can be visualized with high contrast and sensitivity in real time by subtraction of the fine line pattern in the background of the field of interest from the live video signal.
This technique was used to study the effectiveness of surgical masks, the disturbance of the laminar flow by the exhaust of cooling air from equipment like an operating microscope and surgical navigation system. Due to the real-time visualization, it is possible to focus on the region of interest and the instant effect of e.g. repositioning of equipment. Recording can be analyzed later to quantification.
Real time large field air flow imaging shows to be a sensitive and qualitative technique to study air flows. The awareness of the disturbance of the clean laminar air flow should lead to guidelines to improve the design and positioning of medical equipment in the OR to reduce infections.
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