Mechanical Excitation of Complex Stapes Motion in Guinea Pigs

Errors in measurement of three-dimensional motions of the stapes using a Laser Doppler Vibrometer system

“…With the three-axis piezoelectric actuator, the excitation in the z h direction mainly was expected to generate a piston-like motion (translation in z direction at the footplate center), while the excitations in the x h and y h directions were expected to mainly generate rocking motions about the long and short axes of the footplate (rotations about x and y axes). Though small amounts of undesired motion components were always contained in the induced vibrations, the measured displacements showed a predominant motion in the desired direction of excitations (Eiber et al, 2007).…”

“…1). The actuator, mounted on stacks of micromanipulators, was advanced to the stapes head, and firm contact between the needle tip of the actuator and the stapes head was obtained through microscopic control (Eiber et al, 2007;Huber et al, 2008). Next, the contact was fastened with a monofilament nylon thread of 0.03 mm diameter (9-0 Nylon, S&T AG, Switzerland), which was enclosed in the needle, looped around the stapes head, and pulled by a 0.5 N of a force meter.…”

“…However, the relation between the stimulation intensity and the error in measured velocities has not been quantitatively analyzed, and improvement of the measurement by increasing the stimulation intensity may have a limitation. In most previous measurements and resulting calculations of the 3-D motion components of the stapes (Hato et al, 2003;Eiber et al, 2007;Huber et al, 2008), the position and direction of the stapes in the measurement frame were estimated, and location of the measurement points on the stapes and the relative angular position of the laser beam with respect to the stapes were obtained based on the estimation. Efforts to obtain a more precise position of the stapes with respect to the LDV measurement frame have been made (Decraemer et al, 2007;Sim et al, 2010), but the methods require complicated and delicate setups and procedures.…”

Quasi-static and dynamic motions of the columellar footplate in ostrich ( Struthio camelus ) measured ex vivo

“…These species include human (e.g. von Békésy, 1960;Kirikae, 1960;Heiland et al, 1999;Huber et al, 2001;Hato et al, 2003;Sim et al, 2010), cat (Guinan and Peake, 1967;Decraemer et al, 2000), gerbil (Decraemer et al, 2007;Ravicz et al, 2008) and guinea pig (Eiber et al, 2007;Huber et al, 2008;Eiber et al, 2012). The latter three used mechanical stimulation instead of acoustic stimulation to generate rocking motions on the footplate.…”

Contribution of complex stapes motion to cochlea activation

“…Details about mechanical excitation and measurement procedures used in this study were described in our previous publications (Eiber et al 2007;Breuninger 2008, Huber et al 2008Sim et al 2010b).…”