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Updated: Jun 8, 2026

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Published on: January 5, 2024
Air pulse deformation measurement: a preliminary method for noninvasive vocal fold pliability analysis
Hans Larsson1, P Å Lindestad, S Hertegård
1Department of Logopedics and Phoniatrics, Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden. Hans.Larsson@ki.se
Objective:
A new method, air pulse pliability measurement, is presented, with which the pliability and elasticity of the vocal folds was measured in vitro and in vivo using air pulses. The size of the mucosal movements induced by air pulse stimulation was measured with a laser-based technique.
Subjects And Methods:
The air pulses fed via a 2-mm tubing, introduced through the working channel of a flexible endoscope. Both in vitro and in vivo tests were performed. Nine normal, vocally healthy subjects were examined by air pulse stimulations of the vocal folds, of the skin (cheek and dorsum of the hand) and of the inside of the lips.
Results:
The in vitro tests showed a coefficient of variation of 5% within a range of 1-5 mm from the probe to the surface. The elasticity data showed no differences between vocal folds, lips or cheek. The hand data showed a significantly higher stiffness as compared to the other 3 measuring points (p < 0.001). The coefficient of variation was about 35% for all measuring points, but in ideal conditions on skin it was 9%.
Conclusion:
The results show that the technique allows automatic, quantitative, noninvasive vocal fold pliability measurements on awake subjects.
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