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Compensatory Vocal Folds for Source Voice Generation: Computational Modeling of Vocal Folds Function
Matug, Michal ; Vampola, Tomáš (referee) ; Horáček, Jaromír (referee) ; Švancara, Pavel (advisor)
This doctoral thesis focuses on computational modelling of human vocal folds and vocal tract functions using finite element method (FEM). Human voice is crucial in human communication. Therefore one of the main targets of current medicine is creation of artificial vocal folds, which would substitute the original vocal folds. The computational modelling can be used to understand principles of voice production, determination of parameters that the artificial vocal folds have to meet and verification of their functionality. First part of this thesis focuses on modelling of human voice creation by whisper. Influence of intraglottal gap on eigenvalues distribution for individual vowels was analysed using FEM vocal tract and trachea model. Further there is presented two-dimensional (2D) finite element model of the flow-induced self-oscillation of the human vocal folds in interaction with acoustic spaces of the vocal tract. The 2D vocal tract model was created on the basis of converting the data from magnetic resonance images (MRI). Explicit coupling scheme with separated solvers for structure and fluid domain was used for modelling of the fluid-structure interaction. Created computational model comprises: large deformations of the vocal folds tissue, contact between vocal folds, fluid-structure interaction, morphing the fluid mesh according to the vocal-fold motion (Arbitrary Lagrangian-Eulerian approach), unsteady viscous compressible or incompressible airflow described by the Navier-Stokes equations and airflow separation during glottis closure. This model is used to analyse the influence of stiffness and damping changes in individual vocal fold tissue layers (in particular in superficial lamina propria). Part of this computational analysis is also comparison of vocal folds behaviour for compressible and incompressible flow model. Videokymograms (VKG) are subsequently created from obtained results of FEM calculations which enable to compare individual variants between themselves and with motion of real human vocal folds. In next part of this thesis is presented three-dimensional (3D) finite element model of the flow-induced self-oscillation of the human vocal folds. This 3D model was created from a previous 2D model by extrude to the third direction. Using this model was again compared influence of compressible and incompressible flow model on vocal folds motion and generated sound by using videokymograms and acoustic spectra. The last part of this thesis focuses on the possibility to replace missing natural source voice in form reed-based element. Behaviour of reed-based element was analysed using computational modelling and using measurements on experimental physical model. The physical model enables changes in setting gap between reed and reed stop and performing acoustical and optical measurements.
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Automatic analysis of videokymographic images by means of higher-level features
Zita, Aleš ; Zitová, Barbara (advisor) ; Horáček, Jan (referee)
Human voice diagnosis is a complicated problem, even nowadays. The reason is poor access to the body itself and the high frequencies of vocal fold vibrations. One of the clinically available imaging methods to address these problems is Videokymography - a technology for capturing the vocal fold vibrations using a special line CCD camera. Individual lines stacked on top of each other form videokymographic recording. Videokymographic images are suitable for automatic characteristics extraction, therefore helping to reduce the laryngologist workload. For this purpose, the set of such methods is being developed in the Department of Image Processing in the Institute of Information Theory and Automation of the Academy of Science of Czech Republic. The ventricular band position and shape determination is one of the important, but difficult, tasks. The aim of this thesis is to propose new method of automatic detection of ventricular band on videokymographic recording using digital image processing techniques.
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Analysis of videokymographic images
Zita, Aleš ; Zitová, Barbara (advisor) ; Novozámský, Adam (referee)
In ongoing basic human vocal chord functionality research, scientists try to describe the dependency of the glottal wave characteristics on tone generation and vocal chord properties. One of the affordable vocal chord visualization techniques for clinics is the Videokymography - technique based on recording the vocal chord vibration using a CCD camera modified to a line-scanner. Recorded rows are than combined to form a spatial-time recording. These records are suitable for computer based extraction of the vocal chord characteristics, including the characteristics of the glottal waves. In this thesis the method for automatic detection of the glottal waves was developed and implemented utilizing the digital image processing techniques. The proposed method is primarily focused on processing the healthy vocal chords videokymographic images as they gives us a good reference for the physiology of the human vocal chord organ.
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Automatic analysis of videokymographic images by means of higher-level features
Zita, Aleš
Human voice diagnosis is a complicated problem, even nowadays. The reason is poor access to the body itself and the high frequencies of vocal fold vibrations. One of the clinically available imaging methods to address these problems is Videokymography - a technology for capturing the vocal fold vibrations using a special line CCD camera. Individual lines stacked on top of each other form videokymographic recording. Videokymographic images are suitable for automatic characteristics extraction, therefore helping to reduce the laryngologist workload. For this purpose, the set of such methods is being developed in the Department of Image Processing in the Institute of Information Theory and Automation of the Academy of Science of Czech Republic. The ventricular band position and shape determination is one of the important, but difficult, tasks. The aim of this thesis is to propose new method of automatic detection of ventricular band on videokymographic recording using digital image processing techniques.
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Automatic analysis of videokymographic images by means of higher-level features
Zita, Aleš
Human voice diagnosis is a complicated problem, even nowadays. The reason is poor access to the body itself and the high frequencies of vocal fold vibrations. One of the clinically available imaging methods to address these problems is Videokymography - a technology for capturing the vocal fold vibrations using a special line CCD camera. Individual lines stacked on top of each other form videokymographic recording. Videokymographic images are suitable for automatic characteristics extraction, therefore helping to reduce the laryngologist workload. For this purpose, the set of such methods is being developed in the Department of Image Processing in the Institute of Information Theory and Automation of the Academy of Science of Czech Republic. The ventricular band position and shape determination is one of the important, but difficult, tasks. The aim of this thesis is to propose new method of automatic detection of ventricular band on videokymographic recording using digital image processing techniques.
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Image Analysis in Microscopy and Videokymography
Sedlář, Jiří ; Flusser, Jan (advisor) ; Jan, Jiří (referee) ; Cristobal, Gabriel (referee)
13551398399831-171f83a418df200fec6f622f22b6fb3d.txt The Thesis describes new methods for automatic processing of image data in biology, physics and medicine. The developed methods reconstruct light microscopy images of growing microorganisms in intervals between observations, measure particles in atomic force microscopy images, and evaluate parameters of vocal fold vibrations in videokymographic images. All three problems have been hitherto solved primarily visually. The proposed methods allow automatic or computer-aided processing of the image data, and thus facilitate the evaluation process. Performance of the developed methods was tested on real images; the results were comparable with ground truth or results of visual evaluation. Application of the developed methods is not limited to the specific type of image data; the methods can be used in general for processing of images with similar characteristics. Page 1
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Automatic analysis of videokymographic images by means of higher-level features
Zita, Aleš ; Zitová, Barbara (advisor) ; Horáček, Jan (referee)
Human voice diagnosis is a complicated problem, even nowadays. The reason is poor access to the body itself and the high frequencies of vocal fold vibrations. One of the clinically available imaging methods to address these problems is Videokymography - a technology for capturing the vocal fold vibrations using a special line CCD camera. Individual lines stacked on top of each other form videokymographic recording. Videokymographic images are suitable for automatic characteristics extraction, therefore helping to reduce the laryngologist workload. For this purpose, the set of such methods is being developed in the Department of Image Processing in the Institute of Information Theory and Automation of the Academy of Science of Czech Republic. The ventricular band position and shape determination is one of the important, but difficult, tasks. The aim of this thesis is to propose new method of automatic detection of ventricular band on videokymographic recording using digital image processing techniques.
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Analysis of videokymographic images
Zita, Aleš ; Zitová, Barbara (advisor) ; Novozámský, Adam (referee)
In ongoing basic human vocal chord functionality research, scientists try to describe the dependency of the glottal wave characteristics on tone generation and vocal chord properties. One of the affordable vocal chord visualization techniques for clinics is the Videokymography - technique based on recording the vocal chord vibration using a CCD camera modified to a line-scanner. Recorded rows are than combined to form a spatial-time recording. These records are suitable for computer based extraction of the vocal chord characteristics, including the characteristics of the glottal waves. In this thesis the method for automatic detection of the glottal waves was developed and implemented utilizing the digital image processing techniques. The proposed method is primarily focused on processing the healthy vocal chords videokymographic images as they gives us a good reference for the physiology of the human vocal chord organ.
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