Particle Image Velocimetry of Human Cough

Abstract

Cough generated infectious aerosols are of interest while developing strategies for the mitigation of disease risks ranging from the common cold to SARS. In this work, the velocity field of human cough was measured using particle image velocimetry (PIV). The project subjects (total 29) coughed into an enclosure seeded with stage fog. Cough flow velocity profiles, average widths of the cough jet, and maximum cough velocities were measured. Maximum cough velocities ranged from 1.5 m/s to 28.8 m/s. The average width of all coughs ranged between 35 to 45 mm. Wide variability in the data suggests that future cough simulations consider a range of conditions.

Enhanced spread of expiratory droplets by turbulence in a cough jet

“…The maximum coughing airflow velocity at the mouth has been measured in the order of 10 m/s [13,29,32]. The Schlieren technique using human volunteers reveals the turbulent cough jet with a leading vortex [33], with similar properties to a jet or puff [34]. Trajectories of large droplets from coughing and sneezing were recently visualised by Bourouiba and Bush [35].…”

Transport of Airborne Particles from an Unobstructed Cough Jet

“…The velocity field of human coughs has been extensively examined using various experimental methods, including particle image velocimetry (PIV) (Zhu et al 2006;Chao et al 2009;VanSciver et al 2011;Nishimura et al 2013) and Schlieren imaging (Tang et al 2009). A typical cough has a peak velocity in a range of 6-22 m/s with a duration ranging from 0.25 s to 0.8 s (Zhu et al 2006;Gupta et al 2009).…”

Hospital ventilation simulation for the study of potential exposure to contaminants

“…Starting from critic analysis of literature results and experimental evidence, the present article provides a multiphysics approach to investigate the condition that particles emitted from patients coughing can have a very high probability of interacting with the patient's breathing and vice versa. All the practical difficulties, mainly depending from long time legal permissions, and low cooperation of the technicians of the hospital plants, for realizing experimental measurements (no spot test) in the isolation room e.g., particle image velocimetry (PIV); see Gupta et al 2009;VanSchiver et al 2009), also without patients, made these collected literature results and experimental evidence very important to validate the CFD-FEM simulation. In particular, referring to the steady sate condition, concerning the air distribution and the assessment of the ventilation effectiveness, a good agreement between simulation results and literature can be deduced.…”