Characterisation of the nonlinear elastic behaviour of guinea pig tympanic membrane using micro-fringe projection

Mechanical properties of tympanic membrane (TM) are crucial inputs for modelling acoustic transmission through the ear. In this paper a combined experimental and numerical approach was used to determine the mechanical properties of guinea pig TM under quasi-static condition based on the response of the TM to static pressure. A guinea pig bulla was prepared and the intact TM was subjected to both positive and negative pressures while its topography was measured using the micro-fringe projection technique. Images of the deformed TM were acquired and processed with a phase-shift method to reconstruct the surface profile and determine the volume deformation of the TM under pressures. Finite element method with the implementation of a hyperelastic model was established. The simulated TM deformations under applied pressures demonstrated a good agreement with the measured curves of the pressure-volume displacement relationship. The Young's modulus of guinea pig TM from seven bullas was determined as 15.2-28.3 MP...