The experiments lead by the groups of Dr.Ignazio Maria Viola and Dr. Brian Peterson were conducted using the Background Oriented Schlieren (BOS) technique to visualize breathing and coughing both from a real person and from a manikin.

The studies were performed for the subject (human or manikin) equipped with and without face coverings. Altogether seven types of different face coverings were tested.

Please enjoy watching the results and conclusions of this work, which was featured on ITV news.
A detailed report on this research can be obtained here