Combined plots of all the coughs produced by the 20 healthy volunteers.

<p>These demonstrate the cough airflow dynamic parameters measured in these experiments. <b>A</b>: cough ‘propagation distance-velocity-time’; <b>B:</b> ‘2-D projected area-expansion rate-time’. The parameters digitized directly from the recorded images (propagation distance and 2-D area) are shown by solid red lines with the actual data points as empty circles, with reference to the left y-axis, labeled with the red font. The derived parameters (velocity and 2-D area expansion rate) are shown by thinner, dotted blue lines, with reference to the right y-axis, labeled with the blue font.</p

Experimental set-up of the shadowgraph imaging system.

<p>Schematic of the layout with the large, 1-m diameter, spherical concave f/5 mirror and subject test area at one end, and the high-speed camera with the LED light-source and the image capture system (laptop) approximately 10 m away at the other end of the environmental chamber. Note that the schematic diagram has been shown previously to describe this experimental set-up <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034818#pone.0034818-Tang1" target="_blank">[8]</a>.</p

Characteristics of the 20 healthy human volunteers used in the cough imaging.

<p>Characteristics of the 20 healthy human volunteers used in the cough imaging.</p

A shadowgraph still image of a cough captured from video.

<p>This demonstrates the typical bifurcation of the cough air-stream as a volunteer coughs into his sleeve.</p

Double-sliding door snapshots (side and top views; left-to-right, top-to-bottom).

<p>The series of 4 snapshots with each door-opening, manikin movement scenario were taken with respect to the following events, rather than at specific times: food dye movement due to door-opening motions alone then with any initial manikin movement – manikin interaction and any entrainment food dye – final food dye movements once the manikin had come to rest at its destination position. All movement parameters are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066663#pone-0066663-t001" target="_blank"><b>Table 1</b></a> for these double-sliding door scenarios. Note that with the sliding doors, the scenarios where the manikin enters or leaves the isolation room are effectively symmetrical (unlike with the hinged-door scenarios). <b>A.</b> Manikin moving into/out of the isolation room (seen from outside/inside, respectively), V<b> = </b>0.79 in water (1.22 in air) m/s, door-opening gap velocity = 0.42 in water (0.64 in air) m/s. <b>B.</b> Manikin moving out of/into the isolation room (seen from outside/inside, respectively), V<b> = </b>0.79 in water (1.22 in air) m/s, door-opening gap velocity = 0.42 in water (0.64 in air) m/s.</p

Single-hinged door snapshots (sideviews only; left-to-right).

<p>The series of 4 snapshots with each door-opening, manikin movement scenario were taken with respect to the following events, rather than at specific times: food dye movement due to door-opening motions alone then with any initial manikin movement – manikin interaction and any entrainment food dye – final food dye movements once the manikin had come to rest at its destination position. All movement parameters are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066663#pone-0066663-t002" target="_blank"><b>Table 2</b></a> for these single-hinged door ‘fast’ scenarios. <b>A.</b> Manikin moving into the isolation room (seen from outside, V1 = 0.79 in water (1.22 in air) m/s, angular velocity = 184.68 in water (28.63 in air) deg/s.). <b>B.</b> Manikin moving into the isolation room (seen from inside), V2 = 0.75 in water (1.17 in air) m/s, angular velocity = 184.68 in water (28.63 in air) deg/s. <b>C.</b> Manikin moving out of the isolation room (seen from outside), V<b> = </b>0.77 in water (1.19 in air) m/s; angular velocity = 184.68 in water (28.63 in air) deg/s. <b>D.</b> Manikin moving out of the isolation room (seen from inside), V<b> = </b>0.77 in water (1.19 in air) m/s; angular velocity = 184.68 in water (28.63 in air) deg/s.</p

Photograph of camera and light-source layout.

<p>These images were taken at the stage just before the addition of the colored food dye to one of the chambers in the experimental water-tank.</p

Faster movement parameters for the hinged-door model.

<p>Faster movement parameters for the hinged-door model.</p

Double-hinged door snapshots (sideviews only; left-to-right).

<p>The series of 4 snapshots with each door-opening, manikin movement scenario were taken with respect to the following events, rather than at specific times: food dye movement due to door-opening motions alone then with any initial manikin movement – manikin interaction and any entrainment food dye – final food dye movements once the manikin had come to rest at its destination position. All movement parameters are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066663#pone-0066663-t002" target="_blank"><b>Table 2</b></a> for these double-hinged door ‘fast’ scenarios. <b>A.</b> Manikin moving into the isolation room (seen from outside, V1 = 0.71 in water (1.1 in air) m/s, angular velocity = 163.1 in water (25.3 in air) deg/s.). <b>B.</b> Manikin moving into the isolation room (seen from inside), V2 = 0.88 in water (1.36 in air) m/s, angular velocity = 163.1 in water (25.3 in air) deg/s. <b>C.</b> Manikin moving out of the isolation room (seen from outside), V<b> = </b>0.73 in water (1.14 in air) m/s; angular velocity = 163.1 in water (25.3 in air) deg/s. <b>D.</b> Manikin moving out of the isolation room (seen from inside), V<b> = </b>0.73 in water (1.14 in air) m/s; angular velocity = 163.1 in water (25.3 in air) deg/s.</p