Dimensions of the scala tympani in relation to the diameters of multichannel electrodes

Abstract

Dimensions of the scala tympani were measured at eight different places of 1 3/4 turns of the cochlea, beginning at the round window. Height and width of the scala tympani do not decrease continuously but show enlargements in some places. The diameter of two types of cochlear implants were compared with the mean heights of the scala tympani. The data provide an anatomical basis for the development of cochlear prosthesis, which could be inserted for a longer distance as accomplished hitherto.

Automated analysis of human cochlea shape variability from segmented μ CT images

“…In order to evaluate the internal dimensions of the cochlea, cross-section measurements were performed in radial planes (a.k.a mid-modiolar cross-sections) (Zrunek et al, 1980;Zrunek and Lischka, 1981;Erixon et al, 2009), in parallel planes such as histological sections (Biedron et al, 2010) and in planes normal to the centerline (Poznyakovskiy et al, 2011;Avci et al, 2014). This last method does not induce measurement errors (e.g.…”

“…Methods using several type of plastic casts have been widely employed to evaluate the dimensions of cochlear anatomy (Zrunek et al, 1980;Zrunek and Lischka, 1981;Dimopoulos and Muren, 1990;Hatsushika et al, 1990;Wysocki, 1999;Erixon et al, 2009;RaskAndersen et al, 2011), but they do not allow accurate preservation of the geometric relationships of fragile cochlear structures and artifact-free measurements. Microdissections enable measurements of basic external dimensions of the cochlea like the width of the cochlear base (Wright and Roland, 2005), but as plastic casts, it cannot provide detailed three-dimensional reconstruction.…”

“…Previous analyses include measurements of the length of the cochlea and the number of cochlear turns (Hardy, 1938;Kawano et al, 1996;Skinner et al, 2002;Escudé et al, 2006;Stakhovskaya et al, 2007;Erixon et al, 2009;Gunz et al, 2012;Shin et al, 2013;van der Marel et al, 2014), measurements of the heights, widths and sectional areas of the scala tympani (Zrunek et al, 1980;Zrunek and Lischka, 1981;Hatsushika et al, 1990;Gulya and Steenerson, 1996;Wysocki, 1999;Thorne et al, 1999;Biedron et al, 2010;Avci et al, 2014), the scala vestibuli (Zrunek and Lischka, 1981;Gulya and Steenerson, 1996;Wysocki, 1999;Thorne et al, 1999;Biedron et al, 2010) and the cochlea (Erixon et al, 2009;Shin et al, 2013), measurements of the radial component of the cochlear centerlines (also called cochlear curvature) (Cohen et al, 1996;Baker, 2008;van der Marel et al, 2014), and studies of the longitudinal component of the centerlines of the scala tympani (Avci et al, 2014) and the cochlea itself (Verbist et al, 2009).…”

Revisiting the Anatomy of the Facial Recess: The Boundaries of the Round Window Exposure

“…It has been established that the scala tympani is the optimal region of the cochlea for electrode insertion of a cochlear implant (4). Round window (RW) insertion has some advantages over promontory cochleostomy (5,6).…”

A MEMS Condenser Microphone-Based Intracochlear Acoustic Receiver

“…Methods to measure ICSP are mainly limited by the small dimensions of the fluid-filled cochlea and the spatially constrained surgical access into the cochlea. The sensing component of the applied intracochlear acoustic receiver (ICAR) has to be smaller than the basal part of the scala tympani (ST), with an average cross-sectional height of 1.25 mm and average width of 1.66 mm [6], [7]. Besides the dimensional constraints, an ICAR working in a liquid medium must provide high sensitivity and a low noise floor with a sufficient signal-to-noise ratio (SNR).…”