Figure 1.
Experimental set-up for the shadowgraph imaging of the human respiratory airflows described in this study (reproduced from Tang et al. 2012).
Figure 2.
Illustration of the parameters digitised frame-by-frame from the high-speed airflow images captured from each volunteer: the maximum visible propagation distance (max-X) and the maximum visible 2-dimensional (2-D) area (max-A).
Figure 3.
A: Measured visible propagation distances and derived velocities; B: Measured 2-dimensional (2D) areas and derived expansion rates.
Figure 4.
Nasal breathing airflow parameters.
A: Measured visible propagation distances and derived velocities; B: Measured 2-dimensional (2D) areas and derived expansion rates.
Figure 5.
Mouth breathing airflow parameters.
A: Measured visible propagation distances and derived velocities; B: Measured 2-dimensional (2D) areas and derived expansion rates.
Figure 6.
Reanalysed coughing airflow parameters for comparison.
A: Measured visible propagation distances and derived velocities; B: Measured 2-dimensional (2D) areas and derived expansion rates.