TY - JOUR
T1 - Optical measurements of vocal fold tensile properties
T2 - Implications for phonatory mechanics
AU - Kelleher, Jordan E.
AU - Siegmund, Thomas
AU - Chan, Roger W.
AU - Henslee, Erin A.
N1 - Funding Information:
The authors are grateful to the National Institutes of Health (NIDCD Grant R01 DC006101 ) for funding this investigation. Jordan E. Kelleher is thankful to the National Science Foundation for support in the form of a graduate research fellowship. We would also like to thank Prof. Luc Mongeau at McGill University for suggesting the method for applying a speckle pattern.
PY - 2011/6/3
Y1 - 2011/6/3
N2 - In voice research, in vitro tensile stretch experiments of vocal fold tissues are commonly employed to determine the tissue biomechanical properties. In the standard stretch-release protocol, tissue deformation is computed from displacements applied to sutures inserted through the thyroid and arytenoid cartilages, with the cartilages assumed to be rigid. Here, a non-contact optical method was employed to determine the actual tissue deformation of vocal fold lamina propria specimens from three excised human larynges in uniaxial tensile tests. Specimen deformation was found to consist not only of deformation of the tissue itself, but also deformation of the cartilages, as well as suture alignment and tightening. Stress-stretch curves of a representative load cycle were characterized by an incompressible Ogden model. The initial longitudinal elastic modulus was found to be considerably higher if determined based on optical displacement measurements than typical values reported in the literature. The present findings could change the understanding of the mechanics underlying vocal fold vibration. Given the high longitudinal elastic modulus the lamina propria appeared to demonstrate a substantial level of anisotropy. Consequently, transverse shear could play a significant role in vocal fold vibration, and fundamental frequencies of phonation should be predicted by beam theories accounting for such effects.
AB - In voice research, in vitro tensile stretch experiments of vocal fold tissues are commonly employed to determine the tissue biomechanical properties. In the standard stretch-release protocol, tissue deformation is computed from displacements applied to sutures inserted through the thyroid and arytenoid cartilages, with the cartilages assumed to be rigid. Here, a non-contact optical method was employed to determine the actual tissue deformation of vocal fold lamina propria specimens from three excised human larynges in uniaxial tensile tests. Specimen deformation was found to consist not only of deformation of the tissue itself, but also deformation of the cartilages, as well as suture alignment and tightening. Stress-stretch curves of a representative load cycle were characterized by an incompressible Ogden model. The initial longitudinal elastic modulus was found to be considerably higher if determined based on optical displacement measurements than typical values reported in the literature. The present findings could change the understanding of the mechanics underlying vocal fold vibration. Given the high longitudinal elastic modulus the lamina propria appeared to demonstrate a substantial level of anisotropy. Consequently, transverse shear could play a significant role in vocal fold vibration, and fundamental frequencies of phonation should be predicted by beam theories accounting for such effects.
KW - Biomechanical testing
KW - Elasticity
KW - Fundamental frequency
KW - Optical measurements
KW - Vocal folds
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U2 - 10.1016/j.jbiomech.2011.03.037
DO - 10.1016/j.jbiomech.2011.03.037
M3 - Article
C2 - 21497355
AN - SCOPUS:79956105743
SN - 0021-9290
VL - 44
SP - 1729
EP - 1734
JO - Journal of Biomechanics
JF - Journal of Biomechanics
IS - 9
ER -