As COVID-19 continues to keep people indoors and grocery shoppers six feet apart, many researchers are looking to understand the efficacy of face masks. From N95 respirators to handmade cloth coverings, not all masks are created equal. One way to evaluate how well a mask works is to actually see what’s happening when its wearer coughs or sneezes.
Fortunately, “seeing” a cough is not only possible—it’s been done. Dr. Kyle Gilroy, a field applications engineer for Vision Research, recently performed a series of experiments in his home during the coronavirus pandemic. His aim was to study mask performance using a high-speed imaging technique called Background Oriented Schlieren (BOS), which visualizes airflow based on local refractive index variations.