Full paper: Airflow dynamics of coughing and sneezing in healthy human volunteers from shadowgraph imaging: An aid to aerosol infection control

Abstract

Real-time, non-invasive, shadowgraph imaging was used to estimate airflow dynamic parameters for coughing and sneezing in healthy human volunteers. For coughing, 20 healthy volunteers (10 women, mean age 32.2±12.9 years; 10 men, mean age 25.3±2.5 years) were recruited. For the 10 females: maximum cough propagation distances=0.15-0.5m, maximum velocities=2.2-5.5m/s, maximum 2-D projected areas=0.015-0.070m2, maximum 2-D projected area expansion rates=0.2-0.6m2/s. For the 10 males: maximum cough propagation distances=0.3-0.6m, maximum velocities=3.4-17m/s, maximum 2-D projected areas=0.04- 0.13m2, maximum expansion rates=0.3-1.5m 2/s. For sneezing, only four male volunteers were able to sneeze reliably and repeatedly with the black pepper stimulus: Case 1 (21-years, one sneeze), Case 2 (21-years, three sneezes), Case 3 (32-years, two sneezes), Case 4 (43-years, three sneezes): maximum sneeze propagation distances=0.2-0.6m, maximum velocities=0.8- 4.5m/s, maximum 2-D projected areas=0.03-0.18m 2, maximum expansion rates=0.3-1.4m2/s. Surprisingly, in this healthy volunteer cohort, with this experimental approach, maximum exit velocities were fairly similar for both coughing and sneezing.