Vocal fold Young’s modulus: measurement and models

Elastic characteristics of the pig, sheep and cow vocal folds were measured through a series of in vitro experiments and modeled with parameter optimization. Tissue samples were prepared from the oscillating portions of the laryngeal tissues of pig, sheep and cow excised larynges. Sample strips of the vocal fold tissue were dissected and mounted inside a saline-filled ergometer chamber that was maintained at 37°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 calculated based on the sample length and average cross-sectional area and fitted numerically by combination of linear and exponential models. The Young’s modulus was calculated at low strains by a linear regression between 5% and 15% strain values. Pig vocal folds had the average Young’s modulus of 19.2 ± 4.2 kPa, sheep had average value of 11.7 ± 4.6 kPa, and cow had average value of 29.9 ± 8.2 kPa. 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.

کلیدواژه ها:

Young’s modulus ، nonlinear stress-strain ، vocal fold tissue ، exponential model ، hysteresis