Computational modelling of simulated unilateral vocal fold paralysis*

To improve the voice production of patients with unilateral vocal fold paralysis (UVFP), the thyroplasty procedure (TP) is widely used by inserting an implant surgically into the paralyzed side of the vocal fold (VF) to facilitate VF adduction and vibration. Our cross-disciplinary team has developed a suite of computational tools to simulate the fluid-structure interaction (FSI) of VF vibration, which is coined “PhonoSim”, to improve the TP outcome. This suite includes 3D FEM model of larynx, simplified FSI model with a 1D flow approximation, and high-fidelity 3D FSI model for the VF vibration. We also develop a surgical approach to achieve four different VF configurations: no adduction for open VF, two-side suture to mimic healthy phonation, one-side suture for UVFP, and one-side suture/one-side implant for TP surgery. Ex-vivo MRI scans of four configurations are used to provide the VF geometries. After model reconstructions, a 3D FEM model is utilized to simulate VF adductions, which will provide the adducted geometry and prestress under different conditions for FSI simulations. Simplified FSI simulations are performed for tissue property identification and initial implant design. 3D FSI is utilized to finalize the implant design. Details of these computational components and their combination with the experiment study will be presented.