Engineering Commons^™

Three-Dimensional Vibrometry Of The Human Eardrum With Stroboscopic Lensless Digital Holography, Morteza Khaleghi, Cosme Furlong, Mike Ravicz, Jeffrey T. Cheng, John J. Rosowski

Morteza Khaleghi

The eardrum or tympanic membrane (TM) transforms acoustic energy at the ear canal into mechanical motions of the ossicles. The acousto-mechanical transformer behavior of the TM is determined by its shape, three-dimensional (3-D) motion, and mechanical properties. We have developed an optoelectronic holographic system to measure the shape and 3-D sound-induced displacements of the TM. The shape of the TM is measured with dual-wavelength holographic contouring using a tunable near IR laser source with a central wavelength of 780 nm. 3-D components of sound-induced displacements of the TM are measured with the method of multiple sensitivity vectors using stroboscopic holographic …

Sound-Induced In-Plane And Out-Of-Plane Motion Of Human Tympanic Membranes, Morteza Khaleghi, Jeffrey T. Cheng, Cosme Furlong, John J. Rosowski

Morteza Khaleghi

The acousto-mechanical-transformer behavior of the Tympanic Membrane (TM) is determined by its geometry (shape and thickness) and mechanical properties. The questions of “How the TM couples acoustic energy to the ossicles?” and “How TM shape and vibration affect this series of events?” have yet to be fully answered. Holographic studies of 1D vibrations of the TM have been reported by several groups; however, 3D measurements of TM motions are few. In this study, we use full-field-of-view holographic techniques to measure near simultaneously the shape and 3D sound-induced displacement of cadaveric human TMs. Combinations of shape and 3D displacement measurements are …

Is The 3d Sound-Induced Motion Of The Tympanic Membrane Consistent With Thin-Shell Theory?, Morteza Khaleghi, Cosme Furlong, Jeffrey Tao Cheng, John J. Rosowski

Morteza Khaleghi

The acousto-mechanical-transformer behavior of the tympanic membrane (TM) is determined by its shape and mechanical properties. Holographic studies of 1D vibrations of the TM have been reported by several groups; however, 3D

measurements of TM displacement are few. In this study, we will use full-field-of-view holographic techniques to near simultaneously measure the shape and 3D sound-induced

displacement of cadaveric TMs.

The geometrical constraints imposed by the ear canal make 3D measures of TM displacement in intact ears difficult. However, we can, even in such a confined geometry, measure both a 1D component of sound-induced displacement and

the shape of the …