Finite element modeling of the bird middle ear for the development of new human ossicular prostheses.

In mammals three ossicles transport sound vibrations from the eardrum to the fluid in the inner ear. This system forms an acoustic impedance match, and the mobility between the ossicles protects the cochlea from large quasi-static pressure changes. The middle ear of birds only contains a single ossicle, while hearing functions largely as good as in mammals. In humans with blocked or damaged ossicles, surgeons often replace the entire chain by a rigid prosthesis that directly connects the eardrum to the inner ear. One problem is that this piston can detach from the inner ear due to large quasi-static pressure changes. A good engineering model of the avian ear will lead to a new design of ossicular prostheses for humans. I will build on the results obtained in my master's thesis to develop a detailed finite element model of the eardrum and the ossicle that evolves along its length from rigid bone to soft material. I will measure ossicle vibrations and use my model in inverse analysis to optimize material parameters and find the best match between model and experiment. I will measure 3D motions as the ossicle is proposed to feature a rocking motion rather than a piston-like motion as in humans. The model will show which material parameters and geometric design are essential for the functioning of this ear. I will use these insights to design a virtual ossicular prosthesis that fits the human ear, and test it in human finite element models available in our laboratory.

Keywords:MIDDLE EAR MECHANICS

Disciplines:Biomechanics

Project type:Collaboration project