Vocal Fold Elasticity in the Pig, Sheep, and Cow Larynges

Abstract

Elastic characteristics of the pig, sheep and cow vocal folds were investigated through a series of in vitro experiments. Sample strips of the vocal fold tissue were dissected from pig, sheep and cow vocal folds and mounted inside a saline-filled ergometer chamber that was maintained at 37°C ± 1°C. Sinusoidal elongation was applied on the samples to obtain the passive force measurements. Force and elongation data from the samples were recorded electronically with a dual-servo system (ergometer). Stress-Strain data were compared to characterize the interspecies differences in the elastic properties of vocal folds. Pig vocal folds exhibited the most nonlinear stress-strain relationship, indicating the presence of a high level of collagen fibers. Cow vocal folds had the highest Young's modulus, but the tissue displayed a nearly linear stress-strain profile. Previous studies of phonation in these three species have indicated that pig larynges have the highest range of phonation frequencies, making them a good candidate for animal studies. The current study provides quantitative data for the elastic properties of the oscillating laryngeal tissue in these species and indicates that nonlinear behavior of these tissues may lead to wider oscillation ranges.

Mechanical Characterization of Vocal Fold Tissue: A Review Study

“…39 No correlation between the time-dependent relaxation function and the strain level could be identified. Alipour et al 40 studied the slow-rate and stretch-release behavior of sheep, cow, and porcine vocal folds and compared with that of canine vocal folds. 38 The nonlinear response of porcine vocal folds was most similar to that of human vocal folds.…”

Glottal Airflow Resistance in Excised Pig, Sheep, and Cow Larynges

“…22 The Young's modulus for the superior folds of the porcine larynx was 22.0 kPa, whereas the sheep vocal folds were more pliable with a value of 17.6 kPa. The bovine samples had a higher modulus value (29.9 kPa) but were also longer and thicker.…”

High-Frequency Viscoelastic Shear Properties of Vocal Fold Tissues: Implications for Vocal Fold Tissue Engineering

“…Porcine VFs are the focus of this work owing to their structural similarity to human VFs [30][31][32][33][34][35] and the availability of tissue samples of varying age and gender. The LP of 38 pigs, varying in age from fetal to 2 + -year olds, were tested using the TWE.…”