Quantifying the complexity of excised larynx vibrations from high-speed imaging using spatiotemporal and nonlinear dynamic analyses

Abstract

In this paper, we investigate the biomechanical applications of spatiotemporal analysis and nonlinear dynamic analysis to quantitatively describe regular and irregular vibrations of twelve excised larynges from high-speed image recordings. Regular vibrations show simple spatial symmetry, temporal periodicity, and discrete frequency spectra, while irregular vibrations show complex spatiotemporal plots, aperiodic time series, and broadband spectra. Furthermore, the global entropy and correlation length from spatiotemporal analysis and the correlation dimension from nonlinear dynamic analysis reveal a statistical difference between regular and irregular vibrations. In comparison with regular vibrations, the global entropy and correlation dimension of irregular vibrations are statistically higher, while the correlation length is significantly lower. These findings show that spatiotemporal analysis and nonlinear dynamic analysis are capable of describing the complex dynamics of vocal fold vibrations from high-speed imaging and may potentially be helpful for understanding disordered behaviors in biomedical laryngeal systems.

Spatiotemporal vibratory dynamics of vocal fold scar using high-speed digital imaging

“…This laryngeal pathology may cause biomechanical changes in the viscoelastic properties of the vocal folds. Canine larynges represent an adequate organ model of human phonatory structures [3,6,7]. In the work reported in this Letter, an excised canine larynx is used to produce the pathological condition of a vocal fold scar.…”

“…1b shows nine successive image frames of a scarred larynx. The glottal edges were obtained using the image edge detection method [6,7]. A reference line from the anterior to the posterior ends of the vocal folds was determined.…”

Effects of mucosal loading on vocal fold vibration

“…28 Rich irregular vibratory behaviors, such as bifurcation and chaos, can be found in a voice production system. 4,5,[29][30][31][32][33][34] Some studies have investigated the generation of nonlinear dynamic properties in voice. It has been found that irregular vibratory patterns are related to left-right asymmetry of the vocal folds.…”

08:10: A Rat Excised Larynx Model of Vocal Fold Scar

“…In addition, excised larynx approaches allow the straightforward collection of data that are either challenging or impossible to obtain using human and animal in vivo set-ups, such as the measurement of glottal source parameters without the influence of the vocal tract, the measurement of vocal fold impact stress, and the examination of vocal fold vibration from an inferior or medial (i.e., using a hemilarynx) observation position. Recent work in this area has focused on medial surface dynamics during vocal fold vibration (Döllinger & Berry, 2006a, non-linear pressure-flow and pressure-frequency relationships (Alipour & Jaiswal, in press;Alipour & Scherer, 2007), non-linear vibratory patterns present at high P s (Jiang, Zhang, & Ford, 2003;Jiang, Zhang, & Stern, 2001;Zhang, Jiang, Tao, Bieging, & MacCallum, 2007), flow velocity fields and flow vortices (Khosla, Murugappan, Gutmark, & Scherer, 2007;Khosla, Murugappan, Lakhamraju, & Gutmark, 2008), and the influence of supraglottic anatomy on phonation (Alipour, Jaiswal, & Finnegan, 2007;Döllinger, Berry, & Montequin, 2006;Finnegan & Alipour, in press). …”