Towards modeling of phonation and its recovery in unilateral vocal fold paralysis by fluid-structure interaction.

Introduction: Vocal folds are responsible for sound generation. In unilateral vocal fold paralysis (UVFP), the recurrent laryngeal nerve, which controls the vocal folds, is paralyzed. Medialization laryngoplasty is a surgery in which an implant is inserted to push the paralyzed vocal fold to the centerline to recover phonation.

Methods: Here, a numerical simulation is used to calculate flow-related parameters to give insight into what happens in healthy and treated(implanted) vocal folds and their enhancement. In the present work, airflow over vocal folds is modeled considering fluid-structure interaction (FSI) and varying inlet pressure. The governing equations are discretized for fluid and solid domains and solved using the Galerkin finite element method. The boundary conditions for healthy and unilaterally paralyzed vocal folds were imposed to agree with real cases behavior.

Results: The results showed the effectiveness of medialization laryngoplasty in treating unilateral vocal fold paralysis concerning healthy vocal folds.

Conclusion: This simulation provided a better insight into treatment results for patient-specific cases.