BACKGROUND Functional vocal cord disorders can be a differential diagnosis for postoperative upper airway obstruction requiring urgent intervention.However,this may be unfamiliar to anesthesiologists who would favor i...BACKGROUND Functional vocal cord disorders can be a differential diagnosis for postoperative upper airway obstruction requiring urgent intervention.However,this may be unfamiliar to anesthesiologists who would favor inappropriate airway intervention and increased morbidity.CASE SUMMARY A 61-year-old woman underwent cervical laminectomy,followed by laparoscopic cholecystectomy 10 mo later.Despite adequate reversal of neuromuscular blockade,the patient experienced repetitive respiratory difficulty with inspiratory stridor after extubation.After the second operation,the patient was diagnosed with paradoxical vocal fold motion(PVFM)by an otolaryngologist based on the clinical features and fiberoptic bronchoscopy results,and the patient was successfully treated.CONCLUSION PVFM should be considered a differential diagnosis if a patient presents with stridor after general anesthesia.展开更多
<strong>Objective(s):</strong> The aim of this study is to explore if there is a correlation between the typical voice classification and the morphometric characteristics of the vocal folds, using video la...<strong>Objective(s):</strong> The aim of this study is to explore if there is a correlation between the typical voice classification and the morphometric characteristics of the vocal folds, using video laryngeal stroboscopy, on professional singers in Greece. <strong>Methods:</strong> 70 professional singers, 50% men (35 men) and 50% women (35 women), were recruited for this study. A stroboscopic evaluation was prepared for every participant. Additionally, the voice classification and features of individuals were correlated statistically. <strong>Results:</strong> Statistically significant difference were observed between the voice categories and the size of stomatopharynx, the shape of the hard palate, the length of the vocal folds, the width and thickness of the vocal folds, as well as the tone of speech, in male singers. Statistically significant differences were also observed between the voice categories and all the variables except the shape of epiglottis, the color of speech and the shape of the vocal folds, in female singers. <strong>Conclusions:</strong> There is correlation between the morphometric characteristics of the vocal folds and the voice categories.展开更多
In this work,a three dimensional(3D)convolutional neural network(CNN)model based on image slices of various normal and pathological vocal folds is proposed for accurate and efficient prediction of glottal flows.The 3D...In this work,a three dimensional(3D)convolutional neural network(CNN)model based on image slices of various normal and pathological vocal folds is proposed for accurate and efficient prediction of glottal flows.The 3D CNN model is composed of the feature extraction block and regression block.The feature extraction block is capable of learning low dimensional features from the high dimensional image data of the glottal shape,and the regression block is employed to flatten the output from the feature extraction block and obtain the desired glottal flow data.The input image data is the condensed set of 2D image slices captured in the axial plane of the 3D vocal folds,where these glottal shapes are synthesized based on the equations of normal vibration modes.The output flow data is the corresponding flow rate,averaged glottal pressure and nodal pressure distributions over the glottal surface.The 3D CNN model is built to establish the mapping between the input image data and output flow data.The ground-truth flow variables of each glottal shape in the training and test datasets are obtained by a high-fidelity sharp-interface immersed-boundary solver.The proposed model is trained to predict the concerned flow variables for glottal shapes in the test set.The present 3D CNN model is more efficient than traditional Computational Fluid Dynamics(CFD)models while the accuracy can still be retained,and more powerful than previous data-driven prediction models because more details of the glottal flow can be provided.The prediction performance of the trained 3D CNN model in accuracy and efficiency indicates that this model could be promising for future clinical applications.展开更多
The extended two-mass model is adopted to analyze the nonlinear oscillation of pathological vocal folds during vocalization. Redundant tissue or area in laryngeal patients is modeled as a massless rigid connected to t...The extended two-mass model is adopted to analyze the nonlinear oscillation of pathological vocal folds during vocalization. Redundant tissue or area in laryngeal patients is modeled as a massless rigid connected to the upper mass of the vocal folds, and a parameter Q is introduced to represent the change of glottal configurations and tension imbalance between the left and right sides of vocal folds. Numerical simulations demonstrate that the pathological vocal-fold decreases the threshold of Q to generate nonlinear vocal oscillation, indicating the improvement of the sensitivity of vocal folds to asymmetries and enhancing the coupling between two sides. Furthermore, the pathological vocal-fold can lower the fundamental frequency and eliminate high-order harmonics, For example, the fundamental frequency decreases from 119.94 Hz to 84.95 Hz when Q=0.58 and the sub-glottal pressure 1450 Pa. However, there are no prominent effects on the amplitudes of sub-harmonic and low-order harmonics.展开更多
Human phonation does not merely depend on the vibration of the vocal folds. Research by clinical and computer simulations has demonstrated that the false vocal fold (FVF) is an important laryngeal con-striction that p...Human phonation does not merely depend on the vibration of the vocal folds. Research by clinical and computer simulations has demonstrated that the false vocal fold (FVF) is an important laryngeal con-striction that plays a vital role during human voice production. This study explored the effects of the FVF gaps using both the three-dimensional Plexiglas model and the numerical computation methods. Twelve FVF gaps (ranging from 0.02 to 2.06 cm) were used in this study at three glottal angles (uniform and convergent/divergent 40°), two minimal glottal diameters (Dg) (0.04 cm and 0.06 cm) separately, and the constant subglottal pressure (8 cm H2O). The results suggested that (1) the intralaryngeal pressure was the lowest and the flow was the highest (least flow resistance) when the FVF gap was 1.5-2 times greater than Dg; (2) the divergent glottal angle gave lower pressure and greater flow than the conver-gent and uniform glottal angle as there were no FVF conditions; (3) the presence of the FVF decreased the effects of the glottal angle to a certain extent; and more importantly, (4) the presence of the FVF also moved the separation points downstream, straightened the glottal jet for a longer distance, decreased the overall laryngeal resistance, and reduced the energy dissipation, suggesting the significance of FVF in efficient voice production. These results may be incorporated in the phonatory models (physical or computational) for better understanding of vocal mechanics. The results might also be helpful in exploring the surgical and rehabilitative intervention of related voice problems.展开更多
Objective: To assess patient reported swallowing outcomes before and after injec-tion medialization laryngoplasty in patients with unilateral vocal fold immobility (UVFI). Methods: Case series with chart review of pat...Objective: To assess patient reported swallowing outcomes before and after injec-tion medialization laryngoplasty in patients with unilateral vocal fold immobility (UVFI). Methods: Case series with chart review of patients with UVFI who underwent injection media-lization laryngoplasty at a community laryngology practice by a single clinician between October 2015 and December 2017. Patient-reported validated surveys of swallowing impair-ment, Eating Assessment Tool (EAT-10), demographics, etiology and duration of symptoms were recorded before and after injection. A paired t test was done on EAT-10 surveys before and after IML to assess for statistical significance. Results: Twenty-one patients with UVFI and glottic insufficiency underwent IML between October 2015 and December 2017. Nineteen of 21 patients (90％) presented with dysphagia (EAT-10 ≥ 3). 76％ of patients with dysphagia reported improvement in swallowing function af-ter IML. The EAT-10 scores of UVFI patients with dysphagia before and after IML were 17.0 ± 14.0 and 4.2 ± 9.6, respectively (p = 0.004). Conclusions: Nearly all patients with UVFI and glottic insufficiency report associated dysphagia. Three fourths of these patients perceive improvement in their swallowing function after injection medialization laryngoplasty. Patients with idiopathic UVFI may have a more sus-tained improvement and those with severe preop dysphagia may not benefit. Further research is necessary to refine patient selection and to assess duration of improved swallowing function.展开更多
The geometric and biomechanical properties of the larynx strongly influence voice quality and efficiency. A physical understanding of phonation natures in pathological conditions is important for predictions of how vo...The geometric and biomechanical properties of the larynx strongly influence voice quality and efficiency. A physical understanding of phonation natures in pathological conditions is important for predictions of how voice disorders can be treated using therapy and rehabilitation. Here, we present a continuum-based numerical model of phonation that considers complex fluid-structure interactions occurring in the airway. This model considers a three-dimensional geometry of vocal folds, muscle contractions, and viscoelastic properties to provide a realistic framework of phonation. The vocal fold motion is coupled to an unsteady compressible respiratory flow, allowing numerical simulations of normal and diseased phonations to derive clear relationships between actual laryngeal structures and model parameters such as muscle activity. As a pilot analysis of diseased phonation, we model vocal nodules, the mass lesions that can appear bilaterally on both sides of the vocal folds. Comparison of simulations with and without the nodules demonstrates how the lesions affect vocal fold motion, consequently restricting voice quality. Furthermore, we found that the minimum lung pressure required for voice production increases as nodules move closer to the center of the vocal fold. Thus, simulations using the developed model may provide essential insight into complex phonation phenomena and further elucidate the etiologic mechanisms of voice disorders.展开更多
文摘BACKGROUND Functional vocal cord disorders can be a differential diagnosis for postoperative upper airway obstruction requiring urgent intervention.However,this may be unfamiliar to anesthesiologists who would favor inappropriate airway intervention and increased morbidity.CASE SUMMARY A 61-year-old woman underwent cervical laminectomy,followed by laparoscopic cholecystectomy 10 mo later.Despite adequate reversal of neuromuscular blockade,the patient experienced repetitive respiratory difficulty with inspiratory stridor after extubation.After the second operation,the patient was diagnosed with paradoxical vocal fold motion(PVFM)by an otolaryngologist based on the clinical features and fiberoptic bronchoscopy results,and the patient was successfully treated.CONCLUSION PVFM should be considered a differential diagnosis if a patient presents with stridor after general anesthesia.
文摘<strong>Objective(s):</strong> The aim of this study is to explore if there is a correlation between the typical voice classification and the morphometric characteristics of the vocal folds, using video laryngeal stroboscopy, on professional singers in Greece. <strong>Methods:</strong> 70 professional singers, 50% men (35 men) and 50% women (35 women), were recruited for this study. A stroboscopic evaluation was prepared for every participant. Additionally, the voice classification and features of individuals were correlated statistically. <strong>Results:</strong> Statistically significant difference were observed between the voice categories and the size of stomatopharynx, the shape of the hard palate, the length of the vocal folds, the width and thickness of the vocal folds, as well as the tone of speech, in male singers. Statistically significant differences were also observed between the voice categories and all the variables except the shape of epiglottis, the color of speech and the shape of the vocal folds, in female singers. <strong>Conclusions:</strong> There is correlation between the morphometric characteristics of the vocal folds and the voice categories.
基金supported by the Open Project of Key Laboratory of Computational Aerodynamics,AVIC Aerodynamics Research Institute(Grant No.YL2022XFX0409).
文摘In this work,a three dimensional(3D)convolutional neural network(CNN)model based on image slices of various normal and pathological vocal folds is proposed for accurate and efficient prediction of glottal flows.The 3D CNN model is composed of the feature extraction block and regression block.The feature extraction block is capable of learning low dimensional features from the high dimensional image data of the glottal shape,and the regression block is employed to flatten the output from the feature extraction block and obtain the desired glottal flow data.The input image data is the condensed set of 2D image slices captured in the axial plane of the 3D vocal folds,where these glottal shapes are synthesized based on the equations of normal vibration modes.The output flow data is the corresponding flow rate,averaged glottal pressure and nodal pressure distributions over the glottal surface.The 3D CNN model is built to establish the mapping between the input image data and output flow data.The ground-truth flow variables of each glottal shape in the training and test datasets are obtained by a high-fidelity sharp-interface immersed-boundary solver.The proposed model is trained to predict the concerned flow variables for glottal shapes in the test set.The present 3D CNN model is more efficient than traditional Computational Fluid Dynamics(CFD)models while the accuracy can still be retained,and more powerful than previous data-driven prediction models because more details of the glottal flow can be provided.The prediction performance of the trained 3D CNN model in accuracy and efficiency indicates that this model could be promising for future clinical applications.
基金supported by the National Basic Research Program of China(Grant No. 2011CB707900)the National Natural Science Foundation of China(Grant Nos. 81127901, 11174141 and 11161120324)the State Key Laboratory of Acoustics, Chinese Academy of Sciences
文摘The extended two-mass model is adopted to analyze the nonlinear oscillation of pathological vocal folds during vocalization. Redundant tissue or area in laryngeal patients is modeled as a massless rigid connected to the upper mass of the vocal folds, and a parameter Q is introduced to represent the change of glottal configurations and tension imbalance between the left and right sides of vocal folds. Numerical simulations demonstrate that the pathological vocal-fold decreases the threshold of Q to generate nonlinear vocal oscillation, indicating the improvement of the sensitivity of vocal folds to asymmetries and enhancing the coupling between two sides. Furthermore, the pathological vocal-fold can lower the fundamental frequency and eliminate high-order harmonics, For example, the fundamental frequency decreases from 119.94 Hz to 84.95 Hz when Q=0.58 and the sub-glottal pressure 1450 Pa. However, there are no prominent effects on the amplitudes of sub-harmonic and low-order harmonics.
基金the National Natural Science Foundation of China (Grant No. 30770544)the National Postdoctoral Science Foundation of China (Grant No. 200704211131)
文摘Human phonation does not merely depend on the vibration of the vocal folds. Research by clinical and computer simulations has demonstrated that the false vocal fold (FVF) is an important laryngeal con-striction that plays a vital role during human voice production. This study explored the effects of the FVF gaps using both the three-dimensional Plexiglas model and the numerical computation methods. Twelve FVF gaps (ranging from 0.02 to 2.06 cm) were used in this study at three glottal angles (uniform and convergent/divergent 40°), two minimal glottal diameters (Dg) (0.04 cm and 0.06 cm) separately, and the constant subglottal pressure (8 cm H2O). The results suggested that (1) the intralaryngeal pressure was the lowest and the flow was the highest (least flow resistance) when the FVF gap was 1.5-2 times greater than Dg; (2) the divergent glottal angle gave lower pressure and greater flow than the conver-gent and uniform glottal angle as there were no FVF conditions; (3) the presence of the FVF decreased the effects of the glottal angle to a certain extent; and more importantly, (4) the presence of the FVF also moved the separation points downstream, straightened the glottal jet for a longer distance, decreased the overall laryngeal resistance, and reduced the energy dissipation, suggesting the significance of FVF in efficient voice production. These results may be incorporated in the phonatory models (physical or computational) for better understanding of vocal mechanics. The results might also be helpful in exploring the surgical and rehabilitative intervention of related voice problems.
文摘Objective: To assess patient reported swallowing outcomes before and after injec-tion medialization laryngoplasty in patients with unilateral vocal fold immobility (UVFI). Methods: Case series with chart review of patients with UVFI who underwent injection media-lization laryngoplasty at a community laryngology practice by a single clinician between October 2015 and December 2017. Patient-reported validated surveys of swallowing impair-ment, Eating Assessment Tool (EAT-10), demographics, etiology and duration of symptoms were recorded before and after injection. A paired t test was done on EAT-10 surveys before and after IML to assess for statistical significance. Results: Twenty-one patients with UVFI and glottic insufficiency underwent IML between October 2015 and December 2017. Nineteen of 21 patients (90％) presented with dysphagia (EAT-10 ≥ 3). 76％ of patients with dysphagia reported improvement in swallowing function af-ter IML. The EAT-10 scores of UVFI patients with dysphagia before and after IML were 17.0 ± 14.0 and 4.2 ± 9.6, respectively (p = 0.004). Conclusions: Nearly all patients with UVFI and glottic insufficiency report associated dysphagia. Three fourths of these patients perceive improvement in their swallowing function after injection medialization laryngoplasty. Patients with idiopathic UVFI may have a more sus-tained improvement and those with severe preop dysphagia may not benefit. Further research is necessary to refine patient selection and to assess duration of improved swallowing function.
文摘The geometric and biomechanical properties of the larynx strongly influence voice quality and efficiency. A physical understanding of phonation natures in pathological conditions is important for predictions of how voice disorders can be treated using therapy and rehabilitation. Here, we present a continuum-based numerical model of phonation that considers complex fluid-structure interactions occurring in the airway. This model considers a three-dimensional geometry of vocal folds, muscle contractions, and viscoelastic properties to provide a realistic framework of phonation. The vocal fold motion is coupled to an unsteady compressible respiratory flow, allowing numerical simulations of normal and diseased phonations to derive clear relationships between actual laryngeal structures and model parameters such as muscle activity. As a pilot analysis of diseased phonation, we model vocal nodules, the mass lesions that can appear bilaterally on both sides of the vocal folds. Comparison of simulations with and without the nodules demonstrates how the lesions affect vocal fold motion, consequently restricting voice quality. Furthermore, we found that the minimum lung pressure required for voice production increases as nodules move closer to the center of the vocal fold. Thus, simulations using the developed model may provide essential insight into complex phonation phenomena and further elucidate the etiologic mechanisms of voice disorders.
