Characterization of the Nonlinear Elastic Behavior of Chinchilla Tympanic Membrane Using Micro-fringe Projection

Abstract

The mechanical properties of an intact, full tympanic membrane (TM) inside the bulla of a fresh chinchilla were measured under quasi-static pressure from −1.0 kPa to 1.0 kPa applied on the TM lateral side. Images of the fringes projected onto the TM were acquired by a digital camera connected to a surgical microscope and analyzed using a phase-shift method to reconstruct the surface topography. The relationship between the applied pressure and the resulting volume displacement was determined and analyzed using a finite element model implementing a hyperelastic 2 nd-order Ogden model. Through an inverse method, the best-fit model parameters for the TM were determined to allow the simulation results to agree with the experimental data. The nonlinear stress-strain relationship for the TM of a chinchilla was determined up to an equibiaxial tensile strain of 31% experienced by the TM in the experiments. The average Young's modulus of the chinchilla TM from ten bullas was determined as approximately 19 MPa.

Aural Discomfort Evaluation of Barometric Pressure in High-speed Train

“…Furthermore, to assess quality of interior pressure, proper features should be used to correlate mobility of TM with ear discomfort. Displacement, volume displacement [6] , displacement transfer function (DTF) [7][8] , velocity [9] , velocity transfer function (VTF) [10] are universally employed to explain the dynamics of TM. Displacement and velocity are easy to yield in LS-DYNA, of which displacement is a convincing indicator to weigh the ear discomfort level.…”