Average droplets detected per cough etiquette maneuver. Control: Size and number of droplets expelled by healthy non-smokers when coughing. Data acquired from an expanding unobstructed cough aerosol. CE data: The short distance from the mouth to the barrier prevents the expansion of the cough plume, and the shape of the barrier redirects a more concentrated flow across the measurement zone. The non-expanding concentrated plume would bring droplets travelling in the periphery closer to the center of the plume increasing the number of droplets accounted for. Particles deposited within the fiber network of tissues and surgical masks during the manufacturing process might be dislodged when coughing, hence increasing the number of items detected by the system.
Zayas et al. BMC Public Health 2013 13:811 doi:10.1186/1471-2458-13-811