NUMERICAL SIMULATION OF VIDEOKYMOGRAPHIC IMAGES FROM THE RESULTS OF THE FINITE ELEMENT MODEL

The study presents a two-dimensional (2D) finite element (FE) model of the fluid-structure-acoustic interaction during flow induced self-oscillation of the human vocal folds. The FE model combines the FE models of the vocal folds, the trachea and the simplified human vocal tract shaped for phonation of vowel [ a:]. The fluid-structure interaction is solved using explicit coupling scheme with separated solvers for structure and fluid domain. The developed FE model comprises large deformations of the vocal-fold tissue, vocal-fold contact, fluid-structure interaction, morphing the fluid mesh according to the vocal-fold motion (Arbitrary Lagrangian-Eulerian approach), solution of unsteady viscous compressible airflow described by the Navier-Stokes equations and airflow separation during the glottis closure. The effect of lamina propria thickness and material properties on simulated videokymographic (VKG) images of vocal-fold vibrations are analyzed. Such variation of the lamina propria properties can be caused by certain vocal-fold pathologies such as Reinke's edema. The developed FE model can be used to study relations among pathological changes in vocal folds tissue, the resulting VKG images and the produced sound spectra.