Measurement of the viscoelastic properties of the vocal folds.
OBJECTIVE
Studies of the viscoelastic properties of the vocal folds are normally performed with rheometers that use parallel plates whose interplate space is usually arbitrarily assigned a fixed value. In tissues subject to variation of thickness between samples, fixed gaps could result in different compressions, compromising the comparison among them. We performed an experimental study to determine whether different compressions can lead to different results in measurements of dynamic viscosity (DV) of vocal fold samples.


METHODS
We measured the DV of vocal fold samples of 10 larynges of cadavers under 3 different compression levels, corresponding to 0.2, 0.5, and 10 N on an 8-mm-diameter parallel-plate rheometer.


RESULTS
The DV directly varied with compression. We observed statistically significant differences between the results of 0.2 and 10 N (p = 0.0396) and 0.5 and 10 N (p = 0.0442).


CONCLUSIONS
The study demonstrated that the level of compression influences the DV measure and suggests that a defined compression level should be used in rheometric studies of biological tissues.
Wiikmann
Christian
C
Disciplina de Otorrinolaringologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
da Silva
Marcelo Alves
MA
Arêas
Elizabeth Pinheiro Gomes
EP
Tsuji
Domingos Hiroshi
DH
Sennes
Luiz Ubirajara
LU
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D019245:Compressive Strength / Q000502:physiology; D004548:Elasticity; D005260:Female; D006801:Humans; D007820:Laryngeal Mucosa / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012212:Rheology; D046509:Tissue Culture Techniques; D014783:Viscosity; D014827:Vocal Cords / Q000503:physiopathology*