During the COVID-19 quarantine, Kyle & his family took materials he had from around his house to make a large Background Oriented Schlieren (BOS) setup. The BOS technique allows researchers to image ultra-small changes in the air. In technical terms, this technique is sensitive to refractive index gradients which can be generated by changes in air pressure, temperature, composition, and density. Therefore, it permits the characterization of the gas dynamics during talking, coughing, & sneezing with and without the use of a mask. The setup includes a high-speed camera and a piece of white board with small well-spaced black speckles. When a person coughs, the disturbance in the air can be picked up by the BOS processing (provide by Lavision Inc). The larger the air disturbance, the more motion is detected in the background speckle pattern. The software turns the tiny changes seen in the background into colors. 

Schlieren Setup