Search results for "Vocal folds"
showing 10 items of 10 documents
Energy-based fluid–structure model of the vocal folds
2020
AbstractLumped elements models of vocal folds are relevant research tools that can enhance the understanding of the pathophysiology of many voice disorders. In this paper, we use the port-Hamiltonian framework to obtain an energy-based model for the fluid–structure interactions between the vocal folds and the airflow in the glottis. The vocal fold behavior is represented by a three-mass model and the airflow is described as a fluid with irrotational flow. The proposed approach allows to go beyond the usual quasi-steady one-dimensional flow assumption in lumped mass models. The simulation results show that the proposed energy-based model successfully reproduces the oscillations of the vocal …
A port-Hamiltonian Fluid-Structure Interaction Model for the Vocal folds ⁎ ⁎This work was supported by CONICYT-PFCHA/2017-21170472, and AC3E CONICYT-…
2018
Abstract Fluid-structure interaction models are of special interest for studying the energy transfer between the moving fluid and the mechanical structure in contact. The vocal folds are an example of a fluid-structure system, where the mechanical structure is usually modeled as a mass-spring-damper system. In particular, the estimation of the collision forces of the vocal folds is of high interest in the diagnosis of phonotraumatic voice pathologies. In this context, the port-Hamiltonian modeling framework focuses on the energy flux in the model and the interacting forces. In this paper, we develop a port-Hamiltonian fluid-structure interaction model based on the interconnection methodolog…
Bernoulli effect
2010
Descripción del mecanismo mediante el cual las cuerdas vocales producen los sonidos vocálicos y consonánticos que escuchamos Explanation of the mechanism by which the vocal folds produce the sounds we hear in vowel and voiced consonant.
Hypothesis of whiplike motion as a possible traumatizing mechanism in vocal fold vibration.
2003
The mucosal waves on the vibrating vocal folds may move in anterior-posterior, mediolateral and in caudal-cranial direction. This article discusses the possible significance of the vertical movement from the point of view of mechanical stress in phonation and the formation of vocal fold traumas. It is hypothesized that in certain conditions the vocal folds may behave in cranial direction like a quasi-free end of a long lash producing very rapid vibratory waves (e.g. the waves in a whiplash). This could be detrimental to the tissue structure. The role of phonation type in enhancing/diminishing this effect will also be discussed.
Numerical simulation of glottal flow
2012
In cases of permanent immobility of both vocal folds patients have difficulties with breathing but rarely with voicing. However, clinical experience shows that the shape of the larynx (voice box) seems to have a significant influence on the degree of airflow and breathing pattern. In order to find an optimal geometry of the larynx in terms of easiness for breathing after the surgical change of vocal folds or false vocal cords (ventricular folds), a set of numerical simulations of glottal flow for weakly compressible Navier-Stokes equations has been performed. We compare airflow resistance and volumetric flow rate for several geometry concepts for inspiration as well as expiration. Finally, …
Computational fluid dynamics in the assessment of patients' postoperative status after glottis-widening surgery
2017
Background. Computational fluid dynamics (CFD), a rapidly developing instrument with a number of practical applications, allows calculation and visualization of the changing parameters of airflow in the upper respiratory tract. Objectives. The aim of this study was to demonstrate the advantages of CFD as an instrument for noninvasive tests of the larynx in patients who had undergone surgical treatment due to bilateral vocal fold paralysis. Material and Methods. Surface measurements of the glottic space were made during maximum adduction of the vocal folds. Additionally, the following spirometric parameters were determined: forced vital capacity (FVC), forced expiratory volume in the first s…
Late consequences of traumatic rupture of the diaphragm.
2013
A 54-year-old man was admitted to our clinic due to elevated γ-glutamyltransferase, without any clinical symptoms. About 25 years ago, he had undergone blunt abdominal and thoracic trauma during an accident. No diagnostic measures or therapy had been performed at that time. Serum bilirubin was normal, but the values for alanine transaminase, aspartate transaminase, and alkaline phosphatase were slightly above the reference range. Sonography of the abdomen revealed dilated intrahepatic bile ducts up to 3 mm in diameter and steatosis of the liver grade I. CT scan and MRI of the thorax and abdomen showed a giant hiatal hernia with transposition of upper abdominal organs into the chest. As the …
Previously undiagnosed Reinke edema as a cause of immediate postextubation inspiratory stridor
2015
Reinke edema (RE) is an uncommon lesion of the vocal folds and a potential cause of complications during airway management. We report the case of a woman with previously unknown RE admitted to the intensive care unit who experienced postextubation inspiratory stridor immediately after separation from mechanical ventilation. RE should be considered among causes of postextubation stridor.
Tratamiento de las lesiones precancerosas de las cuerdas vocales.
2006
After peer review of clinical and histological classifications of precancerosis lesions, we studied 180 cases in the period 1982 through 1999. We divided clinically the cases in: leucoplakia, erythroplakia and erythroleucoplakia; and histologically in: LIN 1, LIN 2, LIN 3 e carcinoma in situ. After surgery, we considered, in each group, clinical development with follow-up over five years.
Roentgenological observations on vocal fold length-changes with special reference to register transition and open/covered voice
1992
This paper examines the length-changes of the vocal folds as a function of voice pitch. Changes in normalized vocal fold elongation (strain) were measured indirectly from calcification points in several laryngeal structures from roentgenological exposures during singing. Changes in vocal fold strain are shown to occur mainly in the register transition area, i.e. the area within which all register changes take place. Changes in vocal fold strain appeared similar in male and female subjects. Evidence for different strain patterns in covered and open singing is presented for female subjects: Strain is higher in non-singers and (“incorrect”) open voice, lower in singers and (“correct”) covered …