Evaluation of thin-slice finite-element models for 3D cochlear organ of Corti mechanics

The micromechanics of the cochlear organ of Corti (OoC) are crucial for hearing, yet they remain poorly understood. This study explores a proposed finite-element (FE) modeling approach aimed at capturing the three-dimensional (3D) motion of the OoC under the influence of the traveling wave. This technique uses a thin slice of the cochlea, making computation feasible while preserving the intricate details of its structures. The primary objective of this study was to evaluate the accuracy and limitations of a slice modeling approach using a simple 'OoC' model representation, which is depicted as a semicircular tissue with a fluid channel traversing it. A full-length box model of the mouse cochlea was constructed and tested against experimental measurements, and its slice equivalent was created for the apical region. A Floquet boundary condition was applied at the longitudinal edges of the slice to capture the local effects of the traveling wave. The input pressure and wavenumber-frequency relationship for the slice were derived from the full-length box model. The results show the potential of the slice FE modeling technique with a Floquet boundary condition to accurately capture the transverse, radial, and longitudinal motions of the OoC that are present in the full-length box model.