Development and Response of Materially-Nonlinear, Multi-Layer Synthetic Models of the Human Vocal Folds

2007 ◽  
Author(s):  
James S. Drechsel ◽  
Jacob B. Munger ◽  
Allyson A. Pulsipher ◽  
Scott L. Thomson
Keyword(s):  
Vocal Fold ◽  
Sound Production ◽  
Voice Disorders ◽  
Vocal Folds ◽  
Prevention And Treatment ◽  
Flow Induced Vibrations ◽  
Synthetic Models ◽  
Normal Speech

The human vocal folds are responsible for sound production during normal speech, and a study of their flow-induced vibrations can lead to improved prevention and treatment of voice disorders. However, studying the vocal folds in vivo or using excised larynges has several disadvantages. Therefore, alternatives exist using either synthetic (physical) and/or computational vocal fold models. In order to be physiologically relevant, the behavior and properties of these models must reasonably match those of the human vocal folds.

scholarly journals Concurrent YAP/TAZ and SMAD signaling mediate vocal fold fibrosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryosuke Nakamura ◽  
Nao Hiwatashi ◽  
Renjie Bing ◽  
Carina P. Doyle ◽  
Ryan C. Branski
Keyword(s):  
Vocal Fold ◽  
Vocal Folds ◽  
Nuclear Accumulation ◽  
Smad Pathway ◽  
Surgical Interventions ◽  
Smad Signaling ◽  
Iatrogenic Damage ◽  
Tgf Β1

AbstractVocal fold (VF) fibrosis is a major cause of intractable voice-related disability and reduced quality of life. Excision of fibrotic regions is suboptimal and associated with scar recurrence and/or further iatrogenic damage. Non-surgical interventions are limited, putatively related to limited insight regarding biochemical events underlying fibrosis, and downstream, the lack of therapeutic targets. YAP/TAZ integrates diverse cell signaling events and interacts with signaling pathways related to fibrosis, including the TGF-β/SMAD pathway. We investigated the expression of YAP/TAZ following vocal fold injury in vivo as well as the effects of TGF-β1 on YAP/TAZ activity in human vocal fold fibroblasts, fibroblast-myofibroblast transition, and TGF-β/SMAD signaling. Iatrogenic injury increased nuclear localization of YAP and TAZ in fibrotic rat vocal folds. In vitro, TGF-β1 activated YAP and TAZ in human VF fibroblasts, and inhibition of YAP/TAZ reversed TGF-β1-stimulated fibroplastic gene upregulation. Additionally, TGF-β1 induced localization of YAP and TAZ in close proximity to SMAD2/3, and nuclear accumulation of SMAD2/3 was inhibited by a YAP/TAZ inhibitor. Collectively, YAP and TAZ were synergistically activated with the TGF-β/SMAD pathway, and likely essential for the fibroplastic phenotypic shift in VF fibroblasts. Based on these data, YAP/TAZ may evolve as an attractive therapeutic target for VF fibrosis.

Videostrobolaryngoscopy of Mucus Layer during Vocal Fold Vibration in Patients with Laryngeal Tension-Fatigue Syndrome

2002 ◽  
Vol 111 (6) ◽  
pp. 537-541 ◽  
Author(s):  
Tzu-Yu Hsiao ◽  
Chia-Ming Liu ◽  
Kai-Nan Lin
Keyword(s):  
Mechanical Properties ◽  
Vocal Fold ◽  
Rough Surfaces ◽  
Voice Disorders ◽  
Vocal Folds ◽  
Voice Disorder ◽  
Mucus Layer ◽  
Vocal Fold Vibration ◽  
Fatigue Syndrome ◽  
Functional Dysphonia

The mucus layer on the vocal folds was examined by videostrobolaryngoscopy in patients with laryngeal tension-fatigue syndrome, a chronic functional dysphonia due to vocal abuse and misuse. Besides the findings in previous reports (such as abnormal glottal closure, phase or amplitude asymmetry, and the irregular mucosal wave), the vocal folds during vibration had an uneven mucus surface. The occurrence of an uneven mucus layer on vocal folds was significantly greater in subjects with this voice disorder (83% or 250 of 301 patients in this series) than in those without voice disorders (18.5% or 5 of 27). The increase of mucus viscosity, mucus aggregation, and the formation of rough surfaces on the vocal folds alter the mechanical properties that contribute to vibration of the cover of the vocal folds, and thereby worsen the symptoms of dysphonia in patients with laryngeal tension-fatigue syndrome.

scholarly journals A Deep Learning Enhanced Novel Software Tool for Laryngeal Dynamics Analysis

2021 ◽  
pp. 1-15
Author(s):  
Andreas M. Kist ◽  
Pablo Gómez ◽  
Denis Dubrovskiy ◽  
Patrick Schlegel ◽  
Melda Kunduk ◽  
...  
Keyword(s):  
Neural Networks ◽  
Quantitative Analysis ◽  
High Speed ◽  
Voice Disorders ◽  
Vocal Folds ◽  
Video Data ◽  
Audio Data ◽  
Fully Automatic ◽  
Video And Audio

Purpose High-speed videoendoscopy (HSV) is an emerging, but barely used, endoscopy technique in the clinic to assess and diagnose voice disorders because of the lack of dedicated software to analyze the data. HSV allows to quantify the vocal fold oscillations by segmenting the glottal area. This challenging task has been tackled by various studies; however, the proposed approaches are mostly limited and not suitable for daily clinical routine. Method We developed a user-friendly software in C# that allows the editing, motion correction, segmentation, and quantitative analysis of HSV data. We further provide pretrained deep neural networks for fully automatic glottis segmentation. Results We freely provide our software Glottis Analysis Tools (GAT). Using GAT, we provide a general threshold-based region growing platform that enables the user to analyze data from various sources, such as in vivo recordings, ex vivo recordings, and high-speed footage of artificial vocal folds. Additionally, especially for in vivo recordings, we provide three robust neural networks at various speed and quality settings to allow a fully automatic glottis segmentation needed for application by untrained personnel. GAT further evaluates video and audio data in parallel and is able to extract various features from the video data, among others the glottal area waveform, that is, the changing glottal area over time. In total, GAT provides 79 unique quantitative analysis parameters for video- and audio-based signals. Many of these parameters have already been shown to reflect voice disorders, highlighting the clinical importance and usefulness of the GAT software. Conclusion GAT is a unique tool to process HSV and audio data to determine quantitative, clinically relevant parameters for research, diagnosis, and treatment of laryngeal disorders. Supplemental Material https://doi.org/10.23641/asha.14575533

Design of Apparatus for Studying Aerodynamics of Voice Production

2004 ◽  
Author(s):  
Michael Barry
Keyword(s):  
Flow Visualization ◽  
Vocal Fold ◽  
Sound Production ◽  
Vocal Tract ◽  
Vocal Folds ◽  
Flow Speed ◽  
Working Fluid ◽  
Voice Production ◽  
Experimental Apparatus ◽  
Glottal Flow

The design and testing of an experimental apparatus for in vitro study of phonatory aerodynamics (voice production) in humans is presented. The presentation includes not only the details of apparatus design, but flow visualization and Digital Particle Image Velocimetry (DPIV) measurements of the developing flow that occurs during the opening of the constriction from complete closure. The main features of the phonation process have long been understood. A proper combination of air flow from the lungs and of vocal fold tension initiates a vibration of the vocal folds, which in turn valves the airflow. The resulting periodic acceleration of the airstream through the glottis excites the acoustic modes of the vocal tract. It is further understood that the pressure gradient driving glottal flow is related to flow separation on the downstream side of the vocal folds. However, the details of this process and how it may contribute to effects such as aperiodicity of the voice and energy losses in voiced sound production are still not fully grasped. The experimental apparatus described in this paper is designed to address these issues. The apparatus itself consists of a scaled-up duct in which water flows through a constriction whose width is modulated by motion of the duct wall in a manner mimicking vocal fold vibration. Scaling the duct up 10 times and using water as the working fluid allows temporally and spatially resolved measurements of the dynamically similar flow velocity field using DPIV at video standard framing rates (15Hz). Dynamic similarity is ensured by matching the Reynolds number (based on glottal flow speed and glottis width) of 8000, and by varying the Strouhal number (based on vocal fold length, glottal flow speed, and a time scale characterizing the motion of the vocal folds) ranging from 0.01 to 0.1. The walls of the 28 cm × 28 cm test section and the vocal fold pieces are made of clear cast acrylic to allow optical access. The vocal fold pieces are 12.7 cm × 14 cm × 28 cm and are rectangular in shape, except for the surfaces which form the glottis, which are 6.35 cm radius half-circles. Dye injection slots are placed on the upstream side of both vocal field pieces to allow flow visualization. Prescribed motion of the vocal folds is provided by two linear stages. Linear bearings ensure smooth execution of the motion prescribed using a computer interface. Measurements described here use the Laser-Induced Fluorescence (LIF) flow visualization and DPIV techniques and are performed for two Strouhal numbers to assess the effect of opening time on the development of the glottal jet. These measurements are conducted on a plane oriented perpendicular to the glottis, at the duct midplane. LIF measurements use a 5W Argon ion laser to produce a light sheet, which illuminates the dye injected through a slot in each vocal fold piece. Two dye colors are used, one for each side. Quantitative information about the velocity and vorticity fields are obtained through DPIV measurements at the same location as the LIF measurements.

Airflow Characterization Combined With 3D Reconstruction of Rabbit Vocal Cord Based on In-Vivo Phonatory Experiments

2020 ◽  
Author(s):  
Zhipeng Lou ◽  
Junshi Wang ◽  
James J. Daniero ◽  
Haibo Dong ◽  
Jinxiang Xi
Keyword(s):  
3D Reconstruction ◽  
Vocal Cord ◽  
Vocal Fold ◽  
High Speed ◽  
3D Model ◽  
Vocal Folds ◽  
Computational Effort ◽  
Immersed Boundary ◽  
Vibration Modes

Abstract In this paper, a numerical approach combined with experiments is employed to characterize the airflow through the vocal cord. Rabbits are used to perform in vivo magnetic resonance imaging (MRI) experiments and the MRI scan data are directly imposed for the three-dimensional (3D) reconstruction of a 3D high-fidelity model. The vibration modes are observed via the in vivo high-speed videoendoscopy (HSVM) technique, and the time-dependent glottal height is evaluated dynamically for the validation of the 3D reconstruction model. 72 sets of rabbit in vivo high-speed recordings are evaluated to achieve the most common vibration mode. The reconstruction is mainly based on MRI data and the HSVM records are supporting and validate the 3D model. A sharp-interface immersed-boundary-method (IBM)-based compressible flow solver is employed to compute the airflow. The primary purpose of the computational effort is to characterize the influence of the vocal folds that applied to the airflow and the airflow-induced phonation. The vocal fold kinematics and the vibration modes are quantified and the vortex structures are analyzed under the influence of vocal folds. The results have shown significant effects of the vocal fold height on the vortex structure, vorticity and velocity. The reconstructed 3D model from this work helps to bring insight into further understanding of the rabbit phonation mechanism. The results provide potential improvement for diagnosis of human vocal fold dysfunction and phonation disorder.

Noncontact Determination of the Mechanical Properties of the Human Vocal Folds

2008 ◽  
Author(s):  
Shinji Deguchi ◽  
Kazutaka Kawashima
Keyword(s):  
Mechanical Properties ◽  
Vocal Fold ◽  
Measurement Techniques ◽  
Voice Quality ◽  
Vocal Folds ◽  
In Vivo Measurement ◽  
In Vitro Measurements ◽  
Excited Oscillation

Mechanical properties of the vocal folds (such as stiffness or viscoelastic properties) play an essential role in phonation. They affect not only voice quality but also onset threshold of vocal fold self-excited oscillation, a sound source of voice [1]. Many experimental data on the mechanical properties have been reported so far, in which in vitro [2] or in vivo measurement techniques [3] were employed. In vitro measurements give us detailed information on the mechanical properties, yet it would be required to consider possible loss of freshness of the specimen. Meanwhile, current in vivo measurement methods utilize a thin probe to deform the vocal fold tissue located at the back of the throat and hence need technical skills for the surveyor to successfully obtain its loading-deformation relationship.

Measurement of Young's Modulus in the in Vivo Human Vocal Folds

1993 ◽  
Vol 102 (8) ◽  
pp. 584-591 ◽  
Author(s):  
Quang T. Tran ◽  
Bruce R. Gerratt ◽  
Gerald S. Berke ◽  
Jody Kreiman
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Young’S Modulus ◽  
Nerve Stimulation ◽  
Vocal Fold ◽  
Young's Modulus ◽  
Vocal Folds ◽  
Laryngeal Nerve ◽  
New Device ◽  
Vocal Fold Vibration

Currently, surgeons have no objective means to evaluate and optimize results of phonosurgery intraoperatively. Instead, they usually judge the vocal folds subjectively by visual inspection or by listening to the voice. This paper describes a new device that measures Young's (elastic) modulus values for the human vocal fold intraoperatively. Physiologically, the modulus of the vocal fold may be important in determining the nature of vocal fold vibration in normal and pathologic states. This study also reports the effect of recurrent laryngeal nerve stimulation on Young's modulus of the human vocal folds, measured by means of transcutaneous nerve stimulation techniques. Young's modulus increased with increases in current stimulation to the recurrent laryngeal nerve. Ultimately, Young's modulus values may assist surgeons in optimizing the results of various phonosurgeries.

In Vivo Engineering of the Vocal Fold Extracellular Matrix with Injectable Hyaluronic Acid Hydrogels: Early Effects on Tissue Repair and Biomechanics in a Rabbit Model

2005 ◽  
Vol 114 (9) ◽  
pp. 662-670 ◽  
Author(s):  
Jennifer K. Hansen ◽  
Susan L. Thibeault ◽  
Jennifer F. Walsh ◽  
Xiao Zheng Shu ◽  
Glenn D. Prestwich
Keyword(s):  
Extracellular Matrix ◽  
Hyaluronic Acid ◽  
Vocal Fold ◽  
Wound Repair ◽  
Rabbit Model ◽  
Vocal Folds ◽  
Biomechanical Properties ◽  
Enzyme Linked Immunosorbent Assay ◽  
Early Effects

Objectives: A prospective, controlled animal study was performed to determine whether the use of injectable, chemically modified hyaluronic acid (HA) derivatives at the time of intentional vocal fold resection might facilitate wound repair and preserve the unique viscoelastic properties of the vocal fold extracellular matrix. Methods: We performed bilateral vocal fold biopsies on 33 rabbits. Two groups of rabbits were unilaterally treated with 2 different HA derivatives — Carbylan-SX and HA-DTPH-PEGDA — at the time of resection. Saline was injected as a control into the contralateral fold. The animals were painlessly sacrificed 3 weeks after biopsy and injection. The outcomes measured included histologic fibrosis level, tissue HA level, and tissue viscosity and elasticity. Results: The Carbylan-SX—treated vocal folds were found to have significantly less fibrosis than the saline-treated controls. The levels of HA in the treated vocal folds were not significantly different from those in the controls at 3 weeks as measured by enzyme-linked immunosorbent assay. The Carbylan-SX—treated vocal folds had significantly improved biomechanical properties of elasticity and viscosity. The HA-DTPH-PEGDA injections yielded significantly improved viscosity, but not elasticity. Conclusions: Prophylactic in vivo manipulation of the extracellular matrix with an injectable Carbylan-SX hydrogel appears to induce vocal fold tissue regeneration to yield optimal tissue composition and biomechanical properties favorable for phonation.

scholarly journals Making a diagnosis of different lesions of vocal fold mucosa by contact endoscopy: The first usage in our clinical practice

2005 ◽  
Vol 133 (3-4) ◽  
pp. 134-137 ◽  
Author(s):  
Milan Jovanovic ◽  
Jelena Perovic-Jovanovic ◽  
Sanja Milenkovic
Keyword(s):  
Clinical Practice ◽  
Vocal Fold ◽  
Vocal Folds ◽  
Diagnostic Methods ◽  
Chronic Laryngitis ◽  
Epithelial Layers ◽  
Clinical Conditions ◽  
Cell Changes

During laryngomicroscopy, the superficial layers of vocal fold epithelium can be examined in vivo and in situ by contact endoscopy. Methylene blue is applied initially to stain the epihelial cells of the vocal folds. When in contact with mucosal tissue, this endoscope provides 60 and 150 times magnification and clear visualization of cellular patterns of the superficial epithelial layers. For the first time in our laryngological clinical practice, we confirmed a number of previously established parametars such as regularity and arrangement of the epithelium, nucleus contour, and nucleus-cytoplasm ratio, what all enable recognition and easy evaluation of different clinical conditions such as chronic laryngitis, Reinke.s edema, papiloma dyspiasia or vocal fold carcinoma. The advantage of con- tact endoscopy in vivo and in situ allows for detailed scan and mapping of all cell changes of the whole mucosa surface. All these features definitely classify the contact endoscopy into additional diagnostic methods in laryngology.

Regeneration of Aged Vocal Folds with Basic Fibroblast Growth Factor in a Rat Model: A Preliminary Report

2005 ◽  
Vol 114 (4) ◽  
pp. 304-308 ◽  
Author(s):  
Shigeru Hirano ◽  
Tomoko Tateya ◽  
Hiromi Nagai ◽  
Charles N. Ford ◽  
Ichiro Tateya ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Lamina Propria ◽  
Basic Fibroblast Growth Factor ◽  
Vocal Fold ◽  
Vocal Folds ◽  
Fibroblast Growth ◽  
Collagen Production

Aged vocal folds have been reported to have dense collagen deposition and decreased hyaluronic acid (HA) in the lamina propria. These characteristics are thought to contribute to vocal problems that occur with age (presbyphonia). To restore better viscoelasticity to aged vocal folds, an intervention that might increase HA and decrease collagen production from aged vocal fold fibroblasts would appear to be a potentially useful approach. Our previous in vitro study has revealed that basic fibroblast growth factor (bFGF) consistently stimulates HA production and decreases collagen production from aged rat vocal fold fibroblasts. The present in vivo study examined the effects of intracordal injection of bFGF into aged rats' vocal folds in terms of restoration of HA and collagen distribution in the lamina propria. We injected bFGF transorally into the lamina propria of (unilateral) vocal folds. The injection was repeated 4 times weekly, and rats were painlessly sacrificed 1 week, 1 month, and 2 months after the final injection. Histologic examination revealed that bFGF significantly increased the HA content of the lamina propria up to 2 months, but showed no effect on collagen, even after 2 months. Because it might take longer for excessive collagen to be degraded, further studies are necessary to clarify the long-term effect on collagen. A drug delivery system for bFGF also needs to be developed to maximize its effect in the future. The present study suggested at least a positive effect of bFGF in restoring the HA content in the aged vocal fold lamina propria.

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