Laryngeal Paralyses

1992 ◽  
Vol 35 (3) ◽  
pp. 545-554 ◽  
Author(s):  
Marshall E. Smith ◽  
Gerald S. Berke ◽  
Bruce R. Gerratt ◽  
Jody Kreiman
Keyword(s):  
Vocal Fold ◽  
Model Simulation ◽  
Lower Mass ◽  
Mass Model ◽  
Laryngeal Function ◽  
Biomechanical Behavior ◽  
Complex Modes ◽  
Input Parameters ◽  
Modes Of Vibration

The neurological causes of vocal fold paralyses have been well documented. However, the effect of these disorders on laryngeal vibration is not well understood. A theoretical four-mass model of the larynx, based on the work of Ishizaka and Isshiki (1976) and Koizumi, Taniguchi, and Hiromitsu (1987), was developed and adapted to simulate laryngeal biomechanical behavior. The model was used to evaluate various states of asymmetric laryngeal vibration. Input parameters that relate observed laryngeal function and model simulation were developed. Laryngeal paralyses were simulated by their predicted effect on these parameters. Simulations were compared with available data on glottal vibration in laryngeal paralyses. Complex modes of vibration were seen with certain combinations of asymmetrical lower mass stiffness and initial glottal gap.

Self-Excited Oscillations in Sliding With a Constant Friction Coefficient

1995 ◽  
Author(s):  
George G. Adams
Keyword(s):  
Dry Friction ◽  
Steady State Solution ◽  
Dynamic Interaction ◽  
Positive Real ◽  
Finite Speed ◽  
Sliding Surfaces ◽  
Complex Modes ◽  
Constant Friction ◽  
Modes Of Vibration ◽  
The Coefficient Of Friction

Abstract The sliding of two surfaces with respect to each other involves many interacting phenomena. In this paper a simple model is presented for the dynamic interaction of two dry sliding surfaces. This model consists of a beam on elastic foundation acted upon by a series of moving linear springs, where the springs represent the asperities on one of the surfaces. The coefficient of friction is constant. Although a nominally steady-state solution exists, an analysis of the dynamic problem indicates that the steady solution is dynamically unstable for any finite speed. Eigenvalues with positive real parts give rise to self-excited motion which continues to increase with time. The mechanism responsible for the instability is a result of the interaction of certain complex modes of vibration (which result from the moving springs) with the friction force of the moving springs. It is expected that these vibrations play a role in the behavior of sliding members with dry friction.

Nonlinear Vocal Fold Dynamics in a Two-Mass Model of Speech Arising From Asymmetric Intraglottal Flow

2011 ◽  
Author(s):  
Byron D. Erath ◽  
Matías Zañartu ◽  
Sean D. Peterson ◽  
Michael W. Plesniak
Keyword(s):  
Vocal Fold ◽  
Vocal Tract ◽  
Vocal Folds ◽  
Attractive Alternative ◽  
Nonlinear Phenomena ◽  
Mass Model ◽  
Sustained Oscillations ◽  
Voiced Speech ◽  
Subglottal Pressure ◽  
Vocal Fold Dynamics

Voiced speech is initiated as air is expelled from the lungs and passes through the vocal tract inciting self-sustained oscillations of the vocal folds. While various approaches exist for investigating both normal and pathological speech, the relative inaccessibility of the vocal folds make multi-mass speech models an attractive alternative. Their behavior has been benchmarked with excised larynx experiments, and they have been used as analysis tools for both normal and disordered speech, including investigations of paralysis, vocal tremor, and breathiness. However, during pathological speech, vocal fold motion is often unstructured, resulting in chaotic motion and a wealth of nonlinear phenomena. Unfortunately, current methodologies for multi-mass speech models are unable to replicate the nonlinear vocal fold behavior that often occurs in physiological diseased voice for realistic values of subglottal pressure.

scholarly journals Transcutaneous Laryngeal Ultrasonography for the Assessment of Laryngeal Function After Thyroidectomy: A Review

2019 ◽  
pp. 014556131987048 ◽  
Author(s):  
Bianca Oliveira Ismael da Costa ◽  
Darlyane de Souza Barros Rodrigues ◽  
Ary Serrano Santos ◽  
Leandro Pernambuco
Keyword(s):  
Methodological Quality ◽  
Vocal Fold ◽  
Review Of The Literature ◽  
Cross Sectional ◽  
Laryngeal Function ◽  
Flexible Laryngoscopy ◽  
Vocal Fold Immobility ◽  
Appraisal Tool ◽  
Laryngeal Ultrasonography

Objective: This review set out to examine the applicability of transcutaneous laryngeal ultrasonography (TLUSG) for the assessment of laryngeal function after thyroidectomy. Methods: An integrative review of the literature was performed using Medline/PubMed, LILACS, and SciELO databases. The methodological quality of the studies was analyzed using the appraisal tool for cross-sectional studies. Results: All 8 included articles investigated laryngeal function with regard to the risk of vocal fold immobility after thyroidectomy. The results regarding the diagnostic power of TLUSG for this assessment are controversial, and there is a tendency to use this examination as a screening procedure for subsequent confirmation by flexible laryngoscopy. Conclusions: Transcutaneous laryngeal ultrasonography is a viable, noninvasive, and useful tool to assess laryngeal function after thyroidectomy, but current available evidence suggests that it does not replace flexible laryngoscopy for the diagnosis of vocal fold immobility.

Vocal Fold Diadochokinetic Function of Individuals With Amyotrophic Lateral Sclerosis

1995 ◽  
Vol 4 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Karen A. Renout ◽  
Herbert A. Leeper ◽  
Donna L. Bandur ◽  
Arthur J. Hudson
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Vocal Fold ◽  
Group Discussion ◽  
Vocal Folds ◽  
Laryngeal Function ◽  
Analysis System ◽  
Reduced Rate ◽  
Opening And Closing ◽  
Lateral Sclerosis ◽  
Over Time

This study relates over time the changes in voluntary opening and closing of the vocal folds (vocal fold diadochokinesis, or VFDDK) of patients with amyotrophic lateral sclerosis (ALS). The rate, pattern, and periodicity of VFDDK were examined for 12 ALS subjects with bulbar and 14 subjects with nonbulbar signs of the disease. The acoustical data were analyzed with a commercially available computer-based speech analysis system. ALS patients with bulbar and nonbulbar symptoms demonstrate reduced rate and aperiodic VFDDK as the symptomatology of the neuromotor system progresses. Individuals with bulbar signs show a greater change in vocal fold activity than do the nonbulbar group. Discussion of the clinical implications for initial diagnosis and monitoring of changes over time in motor control of laryngeal function is presented.

Respiratory and Laryngeal Measures of Children and Women With Bilateral Vocal Fold Nodules

1994 ◽  
Vol 37 (6) ◽  
pp. 1229-1243 ◽  
Author(s):  
Christine M. Sapienza ◽  
Elaine T. Stathopoulos
Keyword(s):  
Lung Volume ◽  
Respiratory Function ◽  
Vocal Fold ◽  
Multidimensional Analysis ◽  
Specific Information ◽  
Laryngeal Function ◽  
Voice Production ◽  
Normal Voice ◽  
Vocal Fold Nodules ◽  
Simultaneous Assessment

Simultaneous assessment of laryngeal and respiratory function was completed on 8 children and 10 women with bilateral vocal fold nodules and compared to that of 8 children and 10 women with normal voice production. Laryngeal function for the individuals with bilateral vocal fold nodules was characterized by significantly higher peak, altemating, and minimum glottal airflow. The presence of the high glottal airflow was accompanied by a significantly larger lung volume excursion. Both the children with nodules and those with normal voice showed laryngeal and respiratory function differences when compared to adults. All subject groups demonstrated appropriate laryngeal and respiratory function when increasing intensity from comfortable to loud speech. Simultaneous measurement of laryngeal and respiratory function using a multidimensional analysis of voice production is advocated in the evaluation of voice disorders because it can provide specific information regarding which of the subsystems of voice production are compromised.

Empirical Eigenfunctions and Medial Surface Dynamics of a Human Vocal Fold

2005 ◽  
Vol 44 (03) ◽  
pp. 384-391 ◽  
Author(s):  
N. Tayama ◽  
D. A. Berry ◽  
M. Döllinger
Keyword(s):  
Vocal Fold ◽  
High Speed ◽  
Computational Models ◽  
Imaging System ◽  
Vocal Folds ◽  
Sustained Oscillation ◽  
Medial Surface ◽  
Physical Mechanisms ◽  
Vocal Fold Vibration ◽  
Modes Of Vibration

Summary Objectives: The purpose of this investigation was to use an excised human larynx to substantiate physical mechanisms of sustained vocal fold oscillation over a variety of phonatory conditions. During sustained, flow-induced oscillation, dynamical data was collected from the medial surface of the vocal fold. The method of Empirical Eigenfunctions was used to analyze the data and to probe physical mechanisms of sustained oscillation. Methods: Thirty microsutures were mounted on the medial margin of a human vocal fold. Across five distinct phonatory conditions, the vocal fold was set into oscillation and imaged with a high-speed digital imaging system. The position coordinates of the sutures were extracted from the images and converted into physical coordinates. Empirical Eigenfunctions were computed from the time-varying physical coordinates, and mechanisms of sustained oscillation were explored. Results: Using the method of Empirical Eigenfunctions, physical mechanisms of sustained vocal fold oscillation were substantiated. In particular, the essential dynamics of vocal fold vibration were captured by two dominant Empirical Eigenfunctions. The largest Eigenfunction primarily captured the alternating convergent/ divergent shape of the medial surface of the vocal fold, while the second largest Eigenfunction primarily captured the lateral vibrations of the vocal fold. Conclusions: The hemi-larynx setup yielded a view of the medial surface of the vocal folds, revealing the tissue vibrations which produced sound. Through the use of Empirical Eigenfunctions, the underlying modes of vibration were computed, disclosing physical mechanisms of sustained vocal fold oscillation. The investigation substantiated previous theoretical analyses and yielded significant data to help evaluate and refine computational models of vocal fold vibration.

Vibration Characteristics of Bladed Disc Assemblies

1973 ◽  
Vol 15 (3) ◽  
pp. 165-186 ◽  
Author(s):  
D. J. Ewins
Keyword(s):  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Complex Modes ◽  
Modes Of Vibration ◽  
Excitation Conditions

A study is made to establish the basic vibration characteristics of bladed disc assemblies. An analysis is presented and used to predict the natural frequencies and mode shapes of uniform bladed discs. It is found that there are many more natural frequencies than those indicated by a study of the blade cantilever modes. The effects of blade detuning are studied and found to give rise to irregular and complex modes of vibration. Consideration of the vibration characteristics under typical operating excitation conditions shows that a detuned system is susceptible to many more resonances than is an equivalent tuned system.

Vibrations moléculaires du nitrate de di-μ-hydroxo-bis(diammine) platine (II) [(NH3)2Pt(OH)2Pt(NH3)2](NO3)2. Partie 2: analyse en coordonnées normales

1982 ◽  
Vol 60 (17) ◽  
pp. 2222-2228 ◽  
Author(s):  
Alain J. P. Alix ◽  
Michel Manfait ◽  
Odile Krug ◽  
Théophile Theophanides
Keyword(s):  
Vibrational Energy ◽  
Normal Modes ◽  
Dimeric Complex ◽  
Normal Coordinate ◽  
Model Approximation ◽  
Mass Model ◽  
Deuterated Analog ◽  
Square Planar ◽  
Modes Of Vibration ◽  
Related Compounds

A full normal coordinate analysis of the skeleton [N2′ Pt O2′ Pt N2′] of the di-μ-hydroxo-bis(diammine) platinum(II) nitrate has been performed according to the Point Mass Model approximation and assuming a D2h molecular symmetry.The method of construction of a set of 18 independent symmetry valence coordinates was based on the theory of molecular vibrations in dependent rectilinear coordinates. A refined general valence force field which reproduces satisfactorily the frequencies of the molecule and its deuterated analog has been obtained. Calculations of all distributions of vibrational energy allow us to descry ibe all normal modes of vibration and especially the ones related to the square planar ring modes (Pt2O2) showing evidence of strong couplings.In addition we have calculated independently some fragments of the whole dimeric complex, which may be used for comparison with related compounds.

Partial Thyroarytenoid Myectomy: An Animal Study Investigating a Proposed New Treatment for Adductor Spasmodic Dysphonia

1993 ◽  
Vol 108 (3) ◽  
pp. 256-264 ◽  
Author(s):  
Sheldon H. Genack ◽  
Peak Woo ◽  
Raymond H. Colton ◽  
Donna Goyette
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Nerve Stimulation ◽  
Vocal Fold ◽  
Compound Muscle Action Potential ◽  
Contralateral Side ◽  
Laryngeal Nerve ◽  
Spasmodic Dysphonia ◽  
True Vocal Cord ◽  
Laryngeal Function ◽  
Adductor Spasmodic Dysphonia

A new surgical procedure with potential application for the treatment of adductor spasmodic dysphonia was performed on ten rabbits to assess surgical effects on laryngeal function. Using an external approach, partial unilateral thyroarytenoid (TA) muscle excision was performed through a thyroplasty cartilage window. The contralateral side was left undisturbed as a control. The animals were studied acutely and at 3 months using videolaryngoscopy. Electrophysiologic measurements were recorded at 3 months. The procedure was well tolerated by all animals, with no postoperative infection or aspiration. At 3 months, spontaneous and evoked (recurrent laryngeal nerve stimulation) TA muscle electromyographic potentials were measurable bilaterally. TA compound muscle action potential amplitudes were reduced on the side of myectomy. The threshold of recurrent laryngeal nerve stimulation needed to produce observable vocal fold adduction was increased on the side operated on. Perioperative and long-term (3 months) videolaryngoscopy demonstrated preservation of laryngeal competence with good true vocal cord adduction. Histologic analysis with whole organ sections showed replacement of excised muscle with loose fibroareolar tissue. No evidence of muscle regeneration was observed. The vocal ligament and vocal fold mucosa were intact and undistorted in all specimens. This procedure is technically simple and appears to effectively result in a functional yet weakened TA muscle. Because myectomy includes motor unit end-plate excision, problems associated with reinnervation may be circumvented. TA myectomy may be applicable in patients with focal laryngeal dystonia to decrease muscle spasm.

Effects of Transient Powertrain Shift Dynamics on Vehicle Handling

2004 ◽  
Author(s):  
Taehyun Shim ◽  
Yi Zhang
Keyword(s):  
Model Simulation ◽  
Automatic Transmission ◽  
Transient Behavior ◽  
Drive Shaft ◽  
Lumped Mass ◽  
Mass Model ◽  
Vehicle Handling ◽  
Shaft Torque ◽  
Shift Dynamics ◽  
Suspension Model

This paper investigates the effect of drive shaft torque variations during transmission shifts on vehicle handling performance. In this paper, a lumped mass model for a 4-speed automatic transmission powertrain and a 14-degree-of-freedom vehicle models have been developed and used jointly for the simulation of vehicle transient behavior during the shift processes. In the investigation, the powertrain model is used as the pre-processor to obtain realistic drive shaft torque that reflects the torque variations intrinsic of transmission shifts. The drive shaft torque thus obtained then serves as the input for the vehicle suspension model. This approach provides better accuracy for vehicle handling analysis than the existing approach that assumes a steady state axle torque. A mid-size sedan was used as an example in the investigation. Based on model simulation, vehicle responses to powertrain shift transients under various road conditions were quantitatively analyzed and compared with that obtained by the existing method.

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