Generation and Dissipation of Heat in Vocal Fold Tissue

1985 ◽  
Vol 28 (2) ◽  
pp. 207-215 ◽  
Author(s):  
Donald S. Cooper ◽  
Ingo R. Titze
Keyword(s):  
Temperature Rise ◽  
Thermal Conduction ◽  
Vocal Fold ◽  
Time Course ◽  
Blood Perfusion ◽  
Vocal Folds ◽  
Ambient Air ◽  
Future Studies ◽  
Fine Wire ◽  
Viscous Loss

The power dissipated in the vocal folds during phonation results from viscous loss in the fold tissues and can be estimated on the basis of a simplified representation of the geometry and movement of the folds. Assuming this power is converted into heat, it combines with the effects of muscle contraction, blood perfusion, and thermal conduction to the surface of the folds to determine fold temperature. To isolate the thermomechanical source of heat, the vocal folds of excised larynges were vibrated vertically over a range of frequencies and amplitudes, while the temperature rise in them was measured by inserted fine-wire thermocouples. The temperature rise observed was somewhat smaller than that predicted. This may be partly accounted for by convective and evaporative cooling of the vocal fold as it moved relative to the ambient air. Future studies should consider the time course of heating and vocal fold geometry in more detail.

Extracellular matrix gene expression during wound healing of the injured rat vocal fold

2009 ◽  
Vol 140 (5) ◽  
pp. 757-761 ◽  
Author(s):  
Tsunehisa Ohno ◽  
Shigeru Hirano ◽  
Bernard Rousseau
Keyword(s):  
Vocal Fold ◽  
Vocal Folds ◽  
Hyaluronan Synthase ◽  
Chain Reaction ◽  
Future Studies ◽  
Temporal Regulation ◽  
Molecular Approaches ◽  
Matrix Gene ◽  
Expression Of Genes ◽  
Polymerase Chain

Objectives: To measure the expression of procollagen-I and -III, decorin, and hyaluronan synthase (HAS)-1, −2, and −3 during the inflammatory, proliferative, and remodeling phases of rat vocal fold injury. Study Design: Prospective, animal model. Subjects and Methods: Vocal folds were injured in 30 rats. Injured specimens were harvested on postinjury days 1, 3, 7, 14, 28, and 56. Five uninjured rats were used for polymerase chain reaction (PCR) control. Real-time PCR was used to measure the expression of procollagen-I and -III, decorin, and hyaluronan synthase (HAS)-1, −2, and −3. Results: Compared with control, expression of procollagen-I and -III were significantly decreased on postinjury days 1 and 56; decorin expression was significantly decreased on postinjury days 1, 3, 7, and 56; HAS-1 expression was significantly decreased on postinjury days 3, 7, 14, 28, and 56; HAS-2 expression was significantly decreased on postinjury days 28 and 56; HAS-3 expression was significantly decreased on postinjury day 56. Conclusions: Results revealed time-dependent alterations in the expression of genes coding procollagen-I and -III, decorin, and HAS-1, −2, and −3. Knowledge of the temporal regulation of these genes and underlying histology will be used in future studies to investigate molecular approaches for manipulation of vocal fold injury.

scholarly journals Climate, vocal folds, and tonal languages: Connecting the physiological and geographic dots

2015 ◽  
Vol 112 (5) ◽  
pp. 1322-1327 ◽  
Author(s):  
Caleb Everett ◽  
Damián E. Blasi ◽  
Seán G. Roberts
Keyword(s):  
Environmental Factors ◽  
Vocal Fold ◽  
Vocal Folds ◽  
Ambient Air ◽  
Complex Tone ◽  
Vocal Fold Vibration ◽  
Major Language ◽  
Physiologically Based

We summarize a number of findings in laryngology demonstrating that perturbations of phonation, including increased jitter and shimmer, are associated with desiccated ambient air. We predict that, given the relative imprecision of vocal fold vibration in desiccated versus humid contexts, arid and cold ecologies should be less amenable, when contrasted to warm and humid ecologies, to the development of languages with phonemic tone, especially complex tone. This prediction is supported by data from two large independently coded databases representing 3,700+ languages. Languages with complex tonality have generally not developed in very cold or otherwise desiccated climates, in accordance with the physiologically based predictions. The predicted global geographic–linguistic association is shown to operate within continents, within major language families, and across language isolates. Our results offer evidence that human sound systems are influenced by environmental factors.

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.

scholarly journals Evaluation of Heating Technique of Deformed Reinforcement Using High-Frequency Induction Heating System

2021 ◽  
Vol 11 (11) ◽  
pp. 4947
Author(s):  
Myung-hwan Lim ◽  
Changhee Lee
Keyword(s):  
Reinforced Concrete ◽  
Temperature Rise ◽  
High Frequency ◽  
Thermal Conduction ◽  
Rapid Heating ◽  
Heating System ◽  
Inductive Heating ◽  
Reinforced Steel ◽  
Induction Heating System ◽  
High Frequency Induction

To improve recycling quality, it is necessary to develop a demolition technology that can be combined with existing crushing methods that employ large shredding-efficient equipment. The efficient collection of bones in a segmentation dismantling method must be considered according to the procedure. Furthermore, there is a need for the development of partial dismantling technologies that enable efficient remodeling, maintenance, and reinforcement. In this study, we experimentally investigated the temperature-rise characteristics of reinforced concrete through partial rapid heating during high-frequency induced heating. Accordingly, the chemical and physical vulnerability characteristics of the reinforced concrete were verified by studying the thermal conduction on the surface of the rebars and the cracks caused by the thermal expansion pressure of the rebars. Furthermore, we aimed to verify the applicability of the proposed technology by specifying the vulnerability range of the reinforced concrete based on the heating range, as well as the appropriate energy consumption. We investigated the temperature rise and temperature distribution characteristics of the rebar surfaces based on diameter, length, bar placement conditions, heating distance, heating coil location, and output, using reinforced steel of grade SD345. Maximum powers of 5, 6, and 10 kW, and inductive heating were used to achieve satisfactory results.

High-Speed Imaging to Study an Auto-Oscillating Vocal Fold Replica for Different Initial Conditions

2017 ◽  
Vol 09 (05) ◽  
pp. 1750064 ◽  
Author(s):  
A. Van Hirtum ◽  
X. Pelorson
Keyword(s):  
Vocal Fold ◽  
High Speed ◽  
Initial Conditions ◽  
Vocal Folds ◽  
High Speed Imaging ◽  
Human Voice ◽  
Manual Intervention ◽  
Geometrical Features ◽  
Upstream Pressure

Experiments on mechanical deformable vocal folds replicas are important in physical studies of human voice production to understand the underlying fluid–structure interaction. At current date, most experiments are performed for constant initial conditions with respect to structural as well as geometrical features. Varying those conditions requires manual intervention, which might affect reproducibility and hence the quality of experimental results. In this work, a setup is described which allows setting elastic and geometrical initial conditions in an automated way for a deformable vocal fold replica. High-speed imaging is integrated in the setup in order to decorrelate elastic and geometrical features. This way, reproducible, accurate and systematic measurements can be performed for prescribed initial conditions of glottal area, mean upstream pressure and vocal fold elasticity. Moreover, quantification of geometrical features during auto-oscillation is shown to contribute to the experimental characterization and understanding.

scholarly journals Regression of cephalic index following endoscopic repair of sagittal synostosis

2019 ◽  
Vol 23 (1) ◽  
pp. 54-60
Author(s):  
Nicholas A. Pickersgill ◽  
Gary B. Skolnick ◽  
Sybill D. Naidoo ◽  
Matthew D. Smyth ◽  
Kamlesh B. Patel
Keyword(s):  
Time Course ◽  
Strong Positive Correlation ◽  
Cephalic Index ◽  
Sagittal Synostosis ◽  
Endoscopic Repair ◽  
Future Studies ◽  
Helmet Therapy ◽  
Significant Regression ◽  
Strip Craniectomy

OBJECTIVEMetrics used to quantify preoperative severity and postoperative outcomes for patients with sagittal synostosis include cephalic index (CI), the well-known standard, and the recently described adjusted cephalic index (aCI), which accounts for altered euryon location. This study tracks the time course of these measures following endoscopic repair with orthotic helmet therapy. The authors hypothesize that CI and aCI show significant regression following endoscope-assisted repair.METHODSCT scans or 3D photographs of patients with nonsyndromic sagittal synostosis treated before 6 months of age by endoscope-assisted strip craniectomy and postoperative helmet therapy (n = 41) were reviewed retrospectively at three time points (preoperatively, 0–2 months after helmeting, and > 24 months postoperatively). The CI and aCI were measured at each time point.RESULTSMean CI and aCI increased from 71.8 to 78.2 and 62.7 to 72.4, respectively, during helmet treatment (p < 0.001). At final follow-up, mean CI and aCI had regressed significantly from 78.2 to 76.5 and 72.4 to 69.7, respectively (p < 0.001). The CI regressed in 33 of 41 cases (80%) and aCI in 39 of 41 cases (95%). The authors observed a mean loss of 31% of improvement in aCI achieved through treatment. A strong, positive correlation existed between CI and aCI (R = 0.88).CONCLUSIONSRegression following endoscope-assisted strip craniectomy with postoperative helmet therapy commonly occurs in patients with sagittal synostosis. Future studies are required to determine whether duration of helmet therapy or modifications in helmet design affect regression.

Laryngeal Framework Surgery in the Management of Spasmodic Dysphonia

1989 ◽  
Vol 98 (1) ◽  
pp. 52-54 ◽  
Author(s):  
Harvey M. Tucker
Keyword(s):  
Vocal Fold ◽  
Vocal Folds ◽  
Long Term Results ◽  
Spasmodic Dysphonia ◽  
Management Problem ◽  
Cure Rate ◽  
Adductor Spasmodic Dysphonia ◽  
Laryngeal Framework Surgery ◽  
Selective Lysis

Spasmodic dysphonia continues to be a management problem for otolaryngologists. Selective lysis of the recurrent laryngeal nerve has been useful in the management of this disease. Reported long-term results, however, reveal that spasm recurs in approximately 40% to 50% of initially successful patients in spite of persistence of the unilateral vocal fold paralysis. Although some of these failures can be recaptured with subsequent laser surgery, the overall “cure” rate does not exceed 70%, even in the best hands. The contributions of Isshiki, LeJeune, and Tucker have demonstrated that tension in the vocal folds can be adjusted by laryngeal framework surgery. Experience with 16 patients suffering from adductor spasmodic dysphonia suggests that laryngeal framework surgery is useful in the management of this disorder.

Reinke's Edema: Phonatory Mechanisms and Management Strategies

1997 ◽  
Vol 106 (7) ◽  
pp. 533-543 ◽  
Author(s):  
Steven M. Zeitels ◽  
Glenn W. Bunting ◽  
Robert E. Hillman ◽  
Traci Vaughn
Keyword(s):  
Lamina Propria ◽  
Fundamental Frequency ◽  
Vocal Fold ◽  
Management Strategies ◽  
Vocal Folds ◽  
Vocal Fold Vibration ◽  
Reinke’S Edema ◽  
Subglottal Pressure ◽  
Almost All ◽  
Superficial Lamina

Reinke's edema (RE) has been associated typically with smoking and sometimes with vocal abuse, but aspects of the pathophysiology of RE remain unclear. To gain new insights into phonatory mechanisms associated with RE pathophysiology, weused an integrated battery of objective vocal function tests to analyze 20 patients (19 women) who underwent phonomicrosurgical resection. Preoperative stroboscopic examinations demonstrated that the superficial lamina propria is distended primarily on the superior vocal fold surface. Acoustically, these individuals have an abnormally low average speaking fundamental frequency (123 Hz), and they generate abnormally high average subglottal pressures (9.7 cm H20). The presence of elevated aerodynamic driving pressures reflects difficulties in producing vocal fold vibration that are most likely the result of mass loading associated with RE, and possibly vocal hyperfunction. Furthermore, it is hypothesized that in the environment of chronic glottal mucositis secondary to smoking and reflux, the cephalad force on the vocal folds by the subglottal driving pressure contributes to the superior distention of the superficial lamina propria. Surgical reduction of the volume of the superficial lamina propria resulted in a significant elevation in fundamental frequency (154 Hz) and improvement in perturbation measures. In almost all instances, both the clinician and the patient perceived the voice as improved. However, these patients continued to generate elevated subglottal pressure (probably a sign of persistent hyperfunction) that was accompanied by visually observed supraglottal strain despite the normalsized vocal folds. This finding suggests that persistent hyperfunctional vocal behaviors may contribute to postsurgical RE recurrence if therapeutic strategies are not instituted to modify such behavior.

Effects of Voice Therapy as Objectively Evaluated by Digitized Laryngeal Stroboscopic Imaging

2002 ◽  
Vol 111 (10) ◽  
pp. 902-908 ◽  
Author(s):  
Renée Speyer ◽  
Pieter A. Kempen ◽  
George Wieneke ◽  
Willem Kersing ◽  
Elham Ghazi Hosseini ◽  
...  
Keyword(s):  
Vocal Fold ◽  
Vocal Folds ◽  
Lesion Size ◽  
Voice Therapy ◽  
Benign Lesions ◽  
Objective Measurements ◽  
Significant Parameter ◽  
Surface Areas ◽  
Vocal Fold Vibration ◽  
Maximal Opening

Objective measurements derived from digitized laryngeal stroboscopic images were used to demonstrate changes in vocal fold vibration and in the size of benign lesions after 3 months of voice therapy. Forty chronically dysphonic patients were studied. By means of a rigid stroboscope, pretreatment and posttreatment recordings were made of the vocal folds at rest and under stroboscopic light during phonation. From each recording, images of the positions at rest and during vibration at maximal opening and at maximal closure were digitized. The surface areas of any lesions and of the glottal gap were independently measured in the digitized images by 2 experienced laryngologists. Referential distances were determined in order to compensate for discrepancies in magnification in the various recordings. After 3 months of voice therapy, significant improvement in lesion size and degree of maximal closure during vibration could be demonstrated in about 50% of the patients. The degree of maximal opening did not prove to be a significant parameter.

Immunocytochemical Study of Proteoglycans in Vocal Folds

1996 ◽  
Vol 105 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Agnieszka S. Pawlak ◽  
Elizabeth Hammond ◽  
Thomas Hammond ◽  
Steven D. Gray
Keyword(s):  
Chondroitin Sulfate ◽  
Lamina Propria ◽  
Vocal Fold ◽  
Keratan Sulfate ◽  
Vocal Folds ◽  
Basement Membrane Zone ◽  
Immunocytochemical Study ◽  
Frozen Sections ◽  
Intense Staining ◽  
Immunocytochemical Techniques

We evaluated the proteoglycan composition of normal vocal folds using immunocytochemical techniques. Frozen sections of 14 normal cadaveric vocal folds were obtained within 12 hours of death and sectioned immediately. Vocal fold sections were stained with antibodies against keratan sulfate, chondroitin sulfate, heparan sulfate proteoglycan (HSPG), decorin, and hyaluronate receptor. We found that the lamina propria has diffuse staining of fibrillar components with keratan sulfate and decorin. Intense staining was observed in the vocal ligament area with keratan sulfate. The HSPG was localized to the basement membrane zone. Chondroitin sulfate, HSPG, and hyaluronate receptor were detected in the cytoplasm of interstitial cells with immunocytochemical characteristics of macrophages. The keratan sulfate distribution suggests that fibromodulin may be significant in normal vocal folds. Production of HSPG and probably versican occurs in macrophages and fibroblasts in the lamina propria.

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