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Stereoscopic high-speed imaging for 3D tracking of coughed saliva droplets in the context of COVID-19 spreading

Roth, Adrian LU ; Mehdi, Stiti LU ; Frantz, David LU and Berrocal, Edouard LU (2022)
Abstract
Droplets generated by talking and coughing play a major role in the spreading of COVID-19. There is thus a need for accurate measurements of the physical properties of exhaled droplets, including their number, speed and direction.
Several challenges are associated with imaging coughed droplets such as high droplet speed near the mouth where both short exposure time to freeze droplet motion and kHz recording rate to resolve their displacement is required. In addition, as a highly non-symmetrical spray system is formed from a cough, three-dimensional visualization is necessary to faithfully capture coughing events. In this work, a 3D, high-speed imaging technique is presented that facilitates such challenging measurements. A laser beam... (More)
Droplets generated by talking and coughing play a major role in the spreading of COVID-19. There is thus a need for accurate measurements of the physical properties of exhaled droplets, including their number, speed and direction.
Several challenges are associated with imaging coughed droplets such as high droplet speed near the mouth where both short exposure time to freeze droplet motion and kHz recording rate to resolve their displacement is required. In addition, as a highly non-symmetrical spray system is formed from a cough, three-dimensional visualization is necessary to faithfully capture coughing events. In this work, a 3D, high-speed imaging technique is presented that facilitates such challenging measurements. A laser beam with a probe volume 15 mm thick - 120 mm high is formed and illuminates droplets exiting the mouth imaged using two high-speed cameras. Data has been recorded for four different male subjects where 3D droplet speed and direction has been extracted for 10 coughs each. The maximum speed for a single cough has been estimated to vary between 11 and 45 m/s and the average droplet speed has been found to be in the range 6.5 - 8.7 m/s. These results will be used as input parameters to improve simulation models of droplet transport in the context of virus spreading. (Less)
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author
; ; and
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
host publication
Proceedings of the 20th International Symposium on Application of Laser and Imaging Techniques to Fluid Mechanics 2022
pages
17 pages
ISBN
978-989-53637-0-4
language
English
LU publication?
yes
id
f19c28e5-1ea2-4ebe-a7bc-b80bdd7e7819
date added to LUP
2023-04-04 14:56:38
date last changed
2023-05-16 13:09:52
@inproceedings{f19c28e5-1ea2-4ebe-a7bc-b80bdd7e7819,
  abstract     = {{Droplets generated by talking and coughing play a major role in the spreading of COVID-19. There is thus a need for accurate measurements of the physical properties of exhaled droplets, including their number, speed and direction.<br/>Several challenges are associated with imaging coughed droplets such as high droplet speed near the mouth where both short exposure time to freeze droplet motion and kHz recording rate to resolve their displacement is required. In addition, as a highly non-symmetrical spray system is formed from a cough, three-dimensional visualization is necessary to faithfully capture coughing events. In this work, a 3D, high-speed imaging technique is presented that facilitates such challenging measurements. A laser beam with a probe volume 15 mm thick - 120 mm high is formed and illuminates droplets exiting the mouth imaged using two high-speed cameras. Data has been recorded for four different male subjects where 3D droplet speed and direction has been extracted for 10 coughs each. The maximum speed for a single cough has been estimated to vary between 11 and 45 m/s and the average droplet speed has been found to be in the range 6.5 - 8.7 m/s. These results will be used as input parameters to improve simulation models of droplet transport in the context of virus spreading.}},
  author       = {{Roth, Adrian and Mehdi, Stiti and Frantz, David and Berrocal, Edouard}},
  booktitle    = {{Proceedings of the 20th International Symposium on Application of Laser and Imaging Techniques to Fluid Mechanics 2022}},
  isbn         = {{978-989-53637-0-4}},
  language     = {{eng}},
  month        = {{07}},
  title        = {{Stereoscopic high-speed imaging for 3D tracking of coughed saliva droplets in the context of COVID-19 spreading}},
  url          = {{https://lup.lub.lu.se/search/files/142575039/lxlaser2022.pdf}},
  year         = {{2022}},
}