Determination of the stresses and strain on the superior surface of excised porcine larynges during phonation using digital image correlation

The stresses and strains acting over the superior surface of excised porcine vocal folds during self-excited, flow-induced vibrations were investigated. Digital image correlation analysis of stereospcopic high speed video data was used. The pre-strain resulting from the initial deformation of the tissue before phonation onset was estimated in four larynges. The kinematics of the vocal folds were also measured with a high temporal resolution using a laser Doppler vibrometer. Chaotic jumps between different vibration modes was observed. Impact stresses were estimated from a model based on Hertzian theory, and isotropic constitutive laws. The results yielded values of compressional stresses near the vocal fold edges that were larger than previously reported data. Comparisons were made with similar data previously obtained for a synthetic silicone replica of the human larynx.