Measurement of cough droplet deposition using the cough machine

We developed a cough machine that can generate human-like cough to evaluate the infection risk in indoor environments. The cough expired volume, propagation distance and velocity of cough, total mass of droplets and droplet size were compared with experimental results of subjects. Using the cough machine, the droplet deposition on horizontal surfaces and the position of facial mucous membranes were measured. It was shown that the number of droplet deposited on the facial mucous membranes decreased drastically over 90 cm. On horizontal surfaces, the droplet deposited most at 50-60 cm and over 90% of the droplet deposited within 90 cm.