Particle Image Velocimetry of Human Cough

Figures & data

FIG. 1 Diagram of apparatus.

FIG. 2 Diagram depicting timing of image frames for PIV measurements.

FIG. 3 PIV of cough flow using theatrical fog.

TABLE 1 Characteristic cough volumetric flow rates from Mahajan et al. (1994) and Singh et al. (1995); corresponding average velocities based on diameter D= 30 mm

Flow rate (L/min)	Average velocity (m/s)
200	4.6
300	6.9
750	17.3
1300	30.0

FIG. 4 Average waveform of a cough. Error bars are the standard deviation of the measurement (n= 145). Distribution statistics and an exponential fit to the data are given.

FIG. 5 Distribution of maximum velocity of each cough at specified locations in x.

FIG. 6 Offset velocity profiles for five representative coughs at x= 50 mm.

FIG. 7 Normalized velocity profiles for each x location, averaged over all coughs.

FIG. 8 Average lower y and upper y locations for 1/2 of centerline velocity. The width, d, was determined from the difference between the upper and lower half velocity locations, then averaged over all coughs (Figure 9). Error bars are the standard deviation.

FIG. 9 Average and standard deviation of the cough flow width as a function of the X distance from mouth.

FIG. 10 Normalized velocity profiles scaled by x + a.

Mahajan , R. P. , Singh , P. , Murty , G. E. and Aitkenhead , A. R. 1994 . Relationship between Expired Lung Volume, Peak Flow Rate and Peak Velocity Time during a Voluntary Cough Manoeuvre. . Br. J. Anaesth. , 72 : 298 – 301 .

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Singh , P. , Mahajan , R. P. , Murty , G. E. and Aitkenhead , A. R. 1995 . Relationship of Peak Flow Rate and Peak Velocity Time during Voluntary Coughing. . Br. J. Anaesth. , 74 : 714 – 716 .

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