Optics and Lasers in Engineering vol:47 issue:3-4 pages:301-309
Workshop on Optical Measurement Techniques for Structures and Systems Leuven, BELGIUM, MAY, 2007
Computer modeling of middle car mechanics is an important tool to investigate its complex behavior, but correct mechanical and elastic parameters are needed to obtain realistic simulations. A possible way to determine eardrum elasticity in situ is the use of point indentation measurements. The eardrum is, however, a small fragile membrane, so a non-contacting high-resolution technique is needed to measure the shape change caused by point indentation. We have developed a projection moire interferometer combined with an indentation actuator and a high-resolution force sensor. The apparatus applies deformations up to I mm, with a resolution of I gm, while the indentation force is measured with a resolution better than 1 mN. The moire set-up delivers height data on 512 x 512 points through phase-shifting, with a height resolution of 15 mu m. Shape recordings are made on a rabbit eardrum at different indentation distances, and indentation force is recorded simultaneously. (C) 2008 Elsevier Ltd. All rights reserved.