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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Descrição de periodicidade do sinal eletroglotográfico durante a emissão dos exercícios de vibração sonorizada de língua e lábios comparados à vogal sustentada /E/ / Comparison of tongue and lip trills with phonation of the sustained vowel /E/ regarding the periodicity of the electroglottographic waveform and the amplitude of the electroglottographic signal

Cordeiro, Gislaine Ferro 28 August 2013 (has links)
INTRODUÇÃO: Os exercícios de vibração sonorizada de lábios e língua têm-se se mostrado eficientes quando utilizados tanto no tratamento de pacientes disfônicos como no aquecimento ou preparação vocal. Há grande variação do coeficiente de contato de um mesmo sinal eletroglotográfico e dificuldade na sincronização da luz estroboscópica durante a emissão dos exercícios de vibração sonorizada de língua e lábios, sendo levantada a possibilidade de aperiodicidade de vibração das pregas vocais durante a execução desses exercícios. OBJETIVO: descrever a vibração das pregas vocais durante a emissão de vibrações sonorizadas de língua e lábios comparando-as com a emissão da vogal /E/ sustentada quanto à regularidade e amplitude dos ciclos vibratórios na eletroglotografia, em cantores eruditos profissionais. METODOLOGIA: Participaram desse estudo 10 cantores eruditos profissionais, que emitiram a vogal /E/ sustentada e os exercícios de vibração sonorizados de língua e de lábios na mesma frequência e intensidade durante a execução da eletroglotografia. Foi realizada a inspeção visual da onda eletroglotográfica, quanto à periodicidade e amplitude, além do espectrograma do sinal quanto aos harmônicos presentes em cada amostra. As amostras foram randomizadas e analisadas por 3 avaliadoras. Além disso, foram extraídas as medidas de jitter e shimmer do sinal eletroglotográfico para confirmação dos resultados, além da frequência da variação de vibração dos exercícios de vibração sonorizada. RESULTADOS: Os avaliadores tiveram coeficiente alfa de Cronbach em mais de 0,9 na maior parte das amostras, indicando alto grau de concordância. Na inspeção visual do sinal eletroglotográfico foi considerada na vogal /E/ sustentada: onda periódica com amplitude regular e harmônicos múltiplos da frequência fundamental. Durante o exercício de vibração sonorizada de língua e lábios foram consideradas onda quase-periódica com amplitude oscilante (frequencia aproximada de 23Hz e 24Hz) e harmônicos múltiplos de 23 Hz e 24Hz,aproximadamente. CONCLUSÃO: os exercícios de vibração sonorizada de língua e de lábios assemelham-se entre si e se diferenciam da emissão da vogal /E/ sustentada tanto nas fortes, quanto nas fracas intensidades. A vibração das pregas vocais são mais periódicas durante a emissão da vogal sustentada do que na produção dos exercícios. Nas vibrações sonorizadas de lábios e de língua a forma e a amplitude da onda Lx se diferenciam entre si, mas com padrão de repetição ao longo do tempo, próximo aos 24 Hz. Esse comportamento gera parciais de harmônicos que sugerem movimentação de onda mucosa concomitante à vibração do ponto articulatório (língua ou lábios) / INTRODUCTION: Lip and tongue trills have been effectively used as vocal warmups in the treatment of dysphonia and in the training of professional voice users. In a previous study, we found that the closed quotient varied widely during tongue and lip trills. We encountered difficulty in synchronizing the stroboscopic illumination with the vocal fold vibration during the trill exercises. We hypothesize that there is aperiodicity of vocal fold vibration during tongue and lip trills. AIM: to compare the vocal fold vibration seen during lip and tongue trills with that seen during phonation of the sustained vowel /E/, in terms of the periodicity of the EGG wave form and the amplitude of the EGG signal, in professional voice users. METHODS: We used electroglottography (EGG) to compare the vocal fold vibration seen during tongue and lip trills with that seen during phonation of the sustained vowel /E/, in terms of the EGG waveform periodicity and signal amplitude, in 10 classically trained, professional singers. The participants produced the sustained vowel /E/ and performed tongue and lip trills at the same frequency and intensity. The periodicity of the waveform and the amplitude of the signal were visually analyzed by three blinded, experienced readers. To confirm the visual analysis results, we measured the jitter and shimmer of the signal and the frequency of variation in vocal fold vibration during the trill exercises. RESULTS: Cronbach\'s alpha coefficient values were high (>0,9), indicating high inter-rater reliability. In sustained vowel /E/ was considered periodic wave and regular amplitude. In tongue and lip trills the waveform EGG was considered quasi-periodic and the amplitude of the EGG signal was classified as oscillating. The mean amplitude was as follows: 24.4 Hz during lip trills performed at high intensity; 24.7 Hz during tongue trills performed at high intensity; 23.3 Hz during lip trills performed at low intensity; and 24.3 Hz during tongue trills performed at low intensity. The jitter and shimmer were higher in lip and tongue trills. The harmonics seen on the narrow-band spectrograms were classified as being multiples of the fundamental frequency for the sustained vowel phonation task and as being below the fundamental frequency for lip and tongue trills, the mean frequency of the harmonics being as follows: 23.7 Hz during lip trills performed at high intensity; 24 Hz during tongue trills performed at high intensity; 23.7 Hz during lip trills performed at low intensity; and 23.2 Hz during tongue trills performed at low intensity. CONCLUSION: In terms of the EGG waveform, tongue trills and lip trills are similar regardless of the intensity at which they are performed (i.e., high or low), differing, however, from the sustained vowel /E/. The vibration of the vocal folds is modified according to the supraglottic movement in trills exercices
52

Descrição de periodicidade do sinal eletroglotográfico durante a emissão dos exercícios de vibração sonorizada de língua e lábios comparados à vogal sustentada /E/ / Comparison of tongue and lip trills with phonation of the sustained vowel /E/ regarding the periodicity of the electroglottographic waveform and the amplitude of the electroglottographic signal

Gislaine Ferro Cordeiro 28 August 2013 (has links)
INTRODUÇÃO: Os exercícios de vibração sonorizada de lábios e língua têm-se se mostrado eficientes quando utilizados tanto no tratamento de pacientes disfônicos como no aquecimento ou preparação vocal. Há grande variação do coeficiente de contato de um mesmo sinal eletroglotográfico e dificuldade na sincronização da luz estroboscópica durante a emissão dos exercícios de vibração sonorizada de língua e lábios, sendo levantada a possibilidade de aperiodicidade de vibração das pregas vocais durante a execução desses exercícios. OBJETIVO: descrever a vibração das pregas vocais durante a emissão de vibrações sonorizadas de língua e lábios comparando-as com a emissão da vogal /E/ sustentada quanto à regularidade e amplitude dos ciclos vibratórios na eletroglotografia, em cantores eruditos profissionais. METODOLOGIA: Participaram desse estudo 10 cantores eruditos profissionais, que emitiram a vogal /E/ sustentada e os exercícios de vibração sonorizados de língua e de lábios na mesma frequência e intensidade durante a execução da eletroglotografia. Foi realizada a inspeção visual da onda eletroglotográfica, quanto à periodicidade e amplitude, além do espectrograma do sinal quanto aos harmônicos presentes em cada amostra. As amostras foram randomizadas e analisadas por 3 avaliadoras. Além disso, foram extraídas as medidas de jitter e shimmer do sinal eletroglotográfico para confirmação dos resultados, além da frequência da variação de vibração dos exercícios de vibração sonorizada. RESULTADOS: Os avaliadores tiveram coeficiente alfa de Cronbach em mais de 0,9 na maior parte das amostras, indicando alto grau de concordância. Na inspeção visual do sinal eletroglotográfico foi considerada na vogal /E/ sustentada: onda periódica com amplitude regular e harmônicos múltiplos da frequência fundamental. Durante o exercício de vibração sonorizada de língua e lábios foram consideradas onda quase-periódica com amplitude oscilante (frequencia aproximada de 23Hz e 24Hz) e harmônicos múltiplos de 23 Hz e 24Hz,aproximadamente. CONCLUSÃO: os exercícios de vibração sonorizada de língua e de lábios assemelham-se entre si e se diferenciam da emissão da vogal /E/ sustentada tanto nas fortes, quanto nas fracas intensidades. A vibração das pregas vocais são mais periódicas durante a emissão da vogal sustentada do que na produção dos exercícios. Nas vibrações sonorizadas de lábios e de língua a forma e a amplitude da onda Lx se diferenciam entre si, mas com padrão de repetição ao longo do tempo, próximo aos 24 Hz. Esse comportamento gera parciais de harmônicos que sugerem movimentação de onda mucosa concomitante à vibração do ponto articulatório (língua ou lábios) / INTRODUCTION: Lip and tongue trills have been effectively used as vocal warmups in the treatment of dysphonia and in the training of professional voice users. In a previous study, we found that the closed quotient varied widely during tongue and lip trills. We encountered difficulty in synchronizing the stroboscopic illumination with the vocal fold vibration during the trill exercises. We hypothesize that there is aperiodicity of vocal fold vibration during tongue and lip trills. AIM: to compare the vocal fold vibration seen during lip and tongue trills with that seen during phonation of the sustained vowel /E/, in terms of the periodicity of the EGG wave form and the amplitude of the EGG signal, in professional voice users. METHODS: We used electroglottography (EGG) to compare the vocal fold vibration seen during tongue and lip trills with that seen during phonation of the sustained vowel /E/, in terms of the EGG waveform periodicity and signal amplitude, in 10 classically trained, professional singers. The participants produced the sustained vowel /E/ and performed tongue and lip trills at the same frequency and intensity. The periodicity of the waveform and the amplitude of the signal were visually analyzed by three blinded, experienced readers. To confirm the visual analysis results, we measured the jitter and shimmer of the signal and the frequency of variation in vocal fold vibration during the trill exercises. RESULTS: Cronbach\'s alpha coefficient values were high (>0,9), indicating high inter-rater reliability. In sustained vowel /E/ was considered periodic wave and regular amplitude. In tongue and lip trills the waveform EGG was considered quasi-periodic and the amplitude of the EGG signal was classified as oscillating. The mean amplitude was as follows: 24.4 Hz during lip trills performed at high intensity; 24.7 Hz during tongue trills performed at high intensity; 23.3 Hz during lip trills performed at low intensity; and 24.3 Hz during tongue trills performed at low intensity. The jitter and shimmer were higher in lip and tongue trills. The harmonics seen on the narrow-band spectrograms were classified as being multiples of the fundamental frequency for the sustained vowel phonation task and as being below the fundamental frequency for lip and tongue trills, the mean frequency of the harmonics being as follows: 23.7 Hz during lip trills performed at high intensity; 24 Hz during tongue trills performed at high intensity; 23.7 Hz during lip trills performed at low intensity; and 23.2 Hz during tongue trills performed at low intensity. CONCLUSION: In terms of the EGG waveform, tongue trills and lip trills are similar regardless of the intensity at which they are performed (i.e., high or low), differing, however, from the sustained vowel /E/. The vibration of the vocal folds is modified according to the supraglottic movement in trills exercices
53

Impacto da mitomicina-C tópica na deposição de colágeno em torno de enxerto de gordura na prega vogal de coelhos: estudo histológico e morfométrico / Impact of topical mitomycin-C in the deposition of collagen around fat grafts in vocal folds of rabbits: histologic and morphometric study

Socher, Jan Alessandro 01 April 2009 (has links)
Desde o início de 1990, a enxertia de gordura na prega vocal é descrita como um método para reparar a insuficiência glótica. O objetivo deste estudo é avaliar os efeitos da aplicação tópica de mitomicina-C no processo cicatricial de enxertos autólogos de gorduras inseridos em pregas vocais de coelhos através da medida da deposição de colágeno. Vinte e oito coelhos foram submetidos a enxertia de gordura em ambas pregas vocais. As pregas vocais direitas recebeu previamente a aplicação tópica de mitomicina-C (0,4mg/ml) durante cinco minutos enquanto que as pregas vocais esquerdas formavam o grupo controle (sem mitomicina-C). Quatro grupos com 6 coelhos cada foram sacrificados com 7, 14, 30 e 90 dias após a cirurgia de enxertia. As pregas vocais foram removidas para estudo histológico com a intenção de quantificar a deposição de colágeno através da coloração por Picrossírius Red sob microscopia polarizada. A deposição de colágeno foi menor em todos os grupos de pregas vocais que receberam aplicação tópica de mitomicina-C quando comparada com as pregas vocais do grupo controle. No presente estudo, a aplicação tópica de mitomicina-C antes da enxertia de gordura reduziu significativamente a deposição de colágeno (p = 0,05). / Since the early 1990s, fat implantation in the vocal fold is described as a method of repairing glottal insufficiency. The aim of this study was to evaluate the effect of topical application of mitomycin in the healing process with collagen deposition measurement around of autologous fat implants inserted in rabbits vocal folds. Twenty-eight rabbits were submitted to a fat implant in the both vocal folds. The right vocal folds received previously topical application of mitomycin (0,4mg/ml) for five minutes and the left vocal folds were the control group (without mitomycin). Four groups of 6 rabbits each were sacrificed 7, 14, 30 and 90 days after the implantation. The samples of the vocal folds were collected for histological analysis with the purpose of quantifying the collagen deposition by Picrosirius Red stain under polarization microscopy. The collagen deposition was lower in all groups of vocal folds with topical application of mitomycin than in control groups. In the present study, the topical application of mitomycin before the fat grafts reduced significantly the collagen deposition (p = 0,05).
54

Efeito cognitivo da estimulação magnética transcraniana profunda no tratamento de pacientes com dor neuropática central: um ensaio clínico aleatorizado, duplamente encoberto, controlado por placebo / Cognitive effect of deep transcranial magnetic stimulation in the treatment of patients with central neuropathic pain: a randomized, double-blind, placebo-controlled trial

Selingardi, Priscila Mara Lorencini 31 October 2018 (has links)
Estimulação Magnética Transcraniana profunda (EMTp) modula estruturas corticais mais profundas, como a Ínsula Posterior Superior (IPS) e o Córtex Cingulado Anterior (CCA) e tem sido usada para tratar condições não anteriormente sensíveis à EMT superficial. No entanto, até o momento, nenhum estudo avaliou os efeitos da EMTp na cognição após várias sessões de estimulação de maneira abrangente, especialmente em pacientes com disfunção cognitiva basal devido a lesões estruturais da SNC. Apresentamos resultados secundários de um estudo randomizado paralelo de três braços sobre os efeitos da EMTp ativa de 10Hz para o CCA ou IPS contra EMTp simulada na avaliação neuropsicológica de 98 pacientes com dor neuropática central submetidos a um curso de 12 semanas (16 sessões) de tratamento. Vários canais cognitivos foram avaliados em um desenho cego (atenção, controle inibitório, velocidade de processamento, flexibilidade mental, fluência verbal-fonêmica e semântica, memória operacional e episódica, cognição global e percepção visual) no início e após o último dia de estimulação. Nós observamos que não há efeitos do córtex Insular Posterior Superior (IPS) ou do Cíngulado Anterior (CCA) comparado com EMTp simulada na dor clínica, apesar do achado antinociceptivo significativo nos limiares térmicos após EMTp- IPS e um efeito ansiolítico significativo de EMTp- CCA comparado com estimulação simulada. Não encontramos efeitos significativos da estimulação ativa para o IPS ou para o CCA em comparação com a estimulação simulada em qualquer um dos domínios cognitivos. Os autores concluíram que a EMTp CCA/IPS de alta frequência e repetidas sessões de longa duração é segura em pacientes com lesões do SNC que apresentam lesões cerebrais estruturais e comprometimento cognitivo significantes / Deep-TMS (dTMS) modulates deeper cortical structures such as the posterior superior insular (PSI) and the anterior cingulate cortices (ACC) and has been used to treat conditions not previously responsive to superficial-TMS. However, to date no study has assessed the effects of dTMS on cognition after several sessions of stimulation in a comprehensive manner, especially in patients with baseline cognitive dysfunction due to SNC structural lesions. We present secondary outcome results form a three-arm parallel randomized trial on the effects of active10Hz dTMS to either the ACC or PSI against sham dTMS on neuropsychological assessment of 98 central neuropathic pain patients undergoing a 12-week (16 sessions) course of treatment. Several cognitive channels were assessed in a blinded design (attention, inhibitory control, processing speed, mental flexibility, verbal fluency-phonemic and semantic, working and episodic memory, global cognition and visual perception) at baseline and after the last day of stimulation. We observed that there were no effects of either posterior insular (PSI) or anterior cingulate cortex (ACC) compared to sham dTMS on clinical pain, despite the finding of a significant anti-nociceptive on thermal thresholds after PSI d- TMS and a significant anxiolytic effect of ACC d-TMS compared to sham stimulation. We found no significant effects of active stimulation to either the PSI or to the ACC compared to sham stimulation in any of the cognitive domains. Long-term repetitive-session high frequency ACC/PSI- dTMS is safe in patients with structural SNC lesions who have baseline significant structural brain lesions and cognitive impairment
55

Functional Tissue Engineering of Myocardium Through Cell Tri-culture

Iyer, Rohin 22 August 2012 (has links)
Cardiac tissue engineering promises to create therapeutic tissue replacements for repair of diseased native myocardium. The main goals of this thesis were four-fold: 1) to evaluate cardiac tissues engineered using multiple cell types including endothelial cells (EC), fibroblasts (FB), and cardiomyocytes (CM); 2) to spatiotemporally track cells in organoids and optimize their seeding percentages for improved function; 3) to enhance vascular cord formation through sequential versus simultaneous seeding of ECs and FBs; and 4) to perform mechanistic studies to elucidate the role of soluble factors in cell-cell communication. Microscale templates fabricated from photocrosslinkable poly(ethylene glycol) diacrylate (PEG-DA) were used for all studies for rapid screening. When ECs and FBs were precultured for two days prior to seeding enriched CMs, cells self-assembled into three-dimensional, beating organoids, compared to simultaneously tricultured EC/ FB / CM which formed non-contractile clusters. Fluorescent dyes were used to label and track each cell type for up to 4 days, demonstrating an even distribution of cells within precultured organoids versus EC clustering in simultaneous triculture. When ECs were seeded first, followed by FBs 24 hours later and CMs 48 hours later, vascular-like cords formed that persisted with time in a seeding density-dependent manner. Vascular endothelial growth factor (VEGF) signaling was quantified, showing higher endogenous VEGF secretion rates in sequential preculture (16.6 ng/mL/hr) compared to undetectable VEGF secretion in simultaneous triculture. Blocking of endogenous VEGF signaling through addition of VEGF antibody / VEGFR2 inhibitor resulted in a significant decrease in mRNA and protein expression of the key cardiac gap junctional marker connexin-43. These findings provide a foundation for future work into the mechanisms governing functional cardiac tissue engineering performance and may aid in the development of novel therapies for heart failure based on growth factor signaling and engineering of vascularized, clinically relevant cardiac tissue patches.
56

Functional Tissue Engineering of Myocardium Through Cell Tri-culture

Iyer, Rohin 22 August 2012 (has links)
Cardiac tissue engineering promises to create therapeutic tissue replacements for repair of diseased native myocardium. The main goals of this thesis were four-fold: 1) to evaluate cardiac tissues engineered using multiple cell types including endothelial cells (EC), fibroblasts (FB), and cardiomyocytes (CM); 2) to spatiotemporally track cells in organoids and optimize their seeding percentages for improved function; 3) to enhance vascular cord formation through sequential versus simultaneous seeding of ECs and FBs; and 4) to perform mechanistic studies to elucidate the role of soluble factors in cell-cell communication. Microscale templates fabricated from photocrosslinkable poly(ethylene glycol) diacrylate (PEG-DA) were used for all studies for rapid screening. When ECs and FBs were precultured for two days prior to seeding enriched CMs, cells self-assembled into three-dimensional, beating organoids, compared to simultaneously tricultured EC/ FB / CM which formed non-contractile clusters. Fluorescent dyes were used to label and track each cell type for up to 4 days, demonstrating an even distribution of cells within precultured organoids versus EC clustering in simultaneous triculture. When ECs were seeded first, followed by FBs 24 hours later and CMs 48 hours later, vascular-like cords formed that persisted with time in a seeding density-dependent manner. Vascular endothelial growth factor (VEGF) signaling was quantified, showing higher endogenous VEGF secretion rates in sequential preculture (16.6 ng/mL/hr) compared to undetectable VEGF secretion in simultaneous triculture. Blocking of endogenous VEGF signaling through addition of VEGF antibody / VEGFR2 inhibitor resulted in a significant decrease in mRNA and protein expression of the key cardiac gap junctional marker connexin-43. These findings provide a foundation for future work into the mechanisms governing functional cardiac tissue engineering performance and may aid in the development of novel therapies for heart failure based on growth factor signaling and engineering of vascularized, clinically relevant cardiac tissue patches.
57

Impacto da mitomicina-C tópica na deposição de colágeno em torno de enxerto de gordura na prega vogal de coelhos: estudo histológico e morfométrico / Impact of topical mitomycin-C in the deposition of collagen around fat grafts in vocal folds of rabbits: histologic and morphometric study

Jan Alessandro Socher 01 April 2009 (has links)
Desde o início de 1990, a enxertia de gordura na prega vocal é descrita como um método para reparar a insuficiência glótica. O objetivo deste estudo é avaliar os efeitos da aplicação tópica de mitomicina-C no processo cicatricial de enxertos autólogos de gorduras inseridos em pregas vocais de coelhos através da medida da deposição de colágeno. Vinte e oito coelhos foram submetidos a enxertia de gordura em ambas pregas vocais. As pregas vocais direitas recebeu previamente a aplicação tópica de mitomicina-C (0,4mg/ml) durante cinco minutos enquanto que as pregas vocais esquerdas formavam o grupo controle (sem mitomicina-C). Quatro grupos com 6 coelhos cada foram sacrificados com 7, 14, 30 e 90 dias após a cirurgia de enxertia. As pregas vocais foram removidas para estudo histológico com a intenção de quantificar a deposição de colágeno através da coloração por Picrossírius Red sob microscopia polarizada. A deposição de colágeno foi menor em todos os grupos de pregas vocais que receberam aplicação tópica de mitomicina-C quando comparada com as pregas vocais do grupo controle. No presente estudo, a aplicação tópica de mitomicina-C antes da enxertia de gordura reduziu significativamente a deposição de colágeno (p = 0,05). / Since the early 1990s, fat implantation in the vocal fold is described as a method of repairing glottal insufficiency. The aim of this study was to evaluate the effect of topical application of mitomycin in the healing process with collagen deposition measurement around of autologous fat implants inserted in rabbits vocal folds. Twenty-eight rabbits were submitted to a fat implant in the both vocal folds. The right vocal folds received previously topical application of mitomycin (0,4mg/ml) for five minutes and the left vocal folds were the control group (without mitomycin). Four groups of 6 rabbits each were sacrificed 7, 14, 30 and 90 days after the implantation. The samples of the vocal folds were collected for histological analysis with the purpose of quantifying the collagen deposition by Picrosirius Red stain under polarization microscopy. The collagen deposition was lower in all groups of vocal folds with topical application of mitomycin than in control groups. In the present study, the topical application of mitomycin before the fat grafts reduced significantly the collagen deposition (p = 0,05).
58

Analyse de la parole continue en vue de la caractérisation des troubles de la voix: traitement du signal, indices acoustiques et évaluation perceptive

Kacha, Abdellah 13 October 2006 (has links)
L’analyse du signal de parole offre un moyen privilégié pour l’évaluation clinique de la qualité de la voix en vue d’un diagnostique et d’une documentation quantitative des pathologies du larynx. Une analyse acoustique présente plusieurs avantages. En plus du coût peu élevé du système d’évaluation, elle est simple à mettre en œuvre, présente un caractère non invasif et documente quantitativement le degré d’enrouement perçu par le clinicien.<p>L’objectif de l’analyse du signal acoustique est d’extraire des indices pertinents permettant de déterminer les caractéristiques de la voix afin de renseigner sur l’état du larynx du locuteur. Dans ce contexte, plusieurs indices acoustiques sont utilisés pour caractériser la parole produite par des locuteurs dysphoniques. Un nombre de ces indices reflète la déviation du signal de parole voisée par rapport à la périodicité parfaite. Les causes de ces dyspériodicités sont diverses :vibrations non modales des cordes vocales, bruit de modulation comprenant les variations cycle à cycle de la durée de cycle (jitter) et de l’amplitude (shimmer) dues aux perturbations externes, bruit additif dû à une turbulence excessive, etc.<p>Les indices acoustiques des dyspériodicités vocales sont souvent obtenus à partir de fragments stationnaires de voyelles soutenues. La raison en est que les voyelles sans attaques et déclins sont faciles à analyser parce que les hypothèses de cyclicité et de stationnarité utilisées par les méthodes d’analyse sont valables pour beaucoup de locuteurs. En effet, les voyelles soutenues peuvent être supposées avec une bonne précision comme produites en maintenant invariant dans le temps les caractéristiques de la source vocale, du conduit vocal et des articulateurs et, donc, les paramètres des perturbations et du bruit sont facilement calculés pour les voyelles soutenues.<p>La plupart des cliniciens considèrent la parole continue plus informative que les voyelles soutenues. Plusieurs arguments en faveur de l’analyse de la parole continue peuvent être avancés. La vibration des cordes vocales doit commuter continuellement pour donner lieu à l’apparition ou l’extinction du voisement, le voisement doit être maintenu alors que l’impédance supra-glottique change constamment, plus particulièrement durant les obstruents, et le larynx doit descendre et monter continuellement. Le larynx fonctionne donc dans des conditions non stationnaires et très variables. La parole continue contient donc les caractéristiques dynamiques de la source de la voix et du conduit vocal tels que l’attaque et le déclin et les variations dans la fréquence fondamentale et l’amplitude. De même, il semble que les locuteurs compensent moins pour leurs problèmes de voix lors de la production de la parole continue que lorsqu’ils produisent des voyelles soutenues.<p>Les méthodes de traitement du signal de parole pour la caractérisation des troubles de la voix sont basées sur les hypothèses de stationnarité et de périodicité locales qui conduisent à des approches heuristiques permettant de détecter et d’isoler les périodes fondamentales ou les harmoniques spectrales. Comme conséquence, des erreurs d’insertion ou d’omission se produisent souvent lors de l’analyse des signaux fortement perturbés. Ces erreurs biaisent numériquement les indices acoustiques. Les mesures objectives ne sont donc fiables que lorsque l’analyse est effectuée sur des voyelles soutenues produites par des locuteurs faiblement ou modérément enroués.<p>La précision des méthodes d’analyse dans le cadre de l’estimation des dyspériodicités vocales est une caractéristique fondamentale. En effet, les perturbations cycle à cycle des durées de cycle peuvent être inférieures à 1 % alors que les perturbations cycle à cycle de l’amplitude peuvent être inférieures à 10 %. Donc, les méthodes de traitement doivent être appliquées avec précaution vis à vis de la précision de mesure pour ne pas biaiser les valeurs numériques. Le bruit de quantification par exemple peut affecter la précision d’estimation s’il n’est pas pris en considération.<p>Cette thèse se focalise sur le développement de méthodes robustes d’analyse acoustiques du signal de parole continue en vue de la caractérisation des troubles de la voix, la définition et l’évaluation d’indices acoustiques pour quantifier les dyspériodicités vocales et le développement d’une méthode d’évaluation perceptive fiable permettant de mesurer et comparer les performances des différentes méthodes d’analyse développées.<p>Les méthodes développées sont de deux types :des méthodes d’analyse par bloc qui opèrent sur des trames de courte durée du signal et des méthodes adaptatives qui permettent d’analyser le signal à chaque échantillon en tenant compte de son caractère non stationnaire.<p>Deux indices acoustiques sont utilisés pour quantifier les dyspériodicités vocales dans le signal de parole. Le premier indice, utilisé conventionnellement dans le cadre de l’évaluation objective de la qualité de la voix, est le rapport signal à dyspériodicité global. La valeur numérique de l’indice global est principalement déterminée par les segments vocaliques et donc il peut masquer certains évènements locaux, notamment dans le cas de l’analyse de la parole continue. Le second indice proposé comme alternative à l’indice global est le rapport signal à dyspériodicité segmental. Il a pour objectif de donner une plus forte pondération aux segments bruités de faibles niveaux qui sont peu pondérés dans le calcul de l’indice global.<p>La méthode d’évaluation perceptive développée est basée sur la comparaison de paires de signaux. Elle permet d’obtenir des résultats fiables même lorsque l’évaluation est réalisée par des auditeurs naïfs n’ayant pas d’expérience dans l’évaluation de la qualité de la voix et permet une grande concordance inter-juges et intra-juges. Les performances de la méthode d’évaluation perceptive basée sur la comparaison de paires de signaux sont comparées à celles de la méthode conventionnelle utilisée en milieu clinique.<p>Les performances des différentes méthodes d’analyse et des indices acoustiques sont mesurées en les testant sur des corpus comprenant des voyelles soutenues et de la parole continue. Les stimuli sont produits par des locuteurs normophoniques et dysphoniques et comprennent une large gamme de pathologies.<p> / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished
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Vliv řízení průtoku vzduchu hlasivkami na dynamickou stabilizaci stoje / Influence of airflow control with vocal cords on dynamic stand stabilization

Rybáčková, Kristýna January 2019 (has links)
Title: The effect of airway control on stance dynamic stability Objectives: The aim of this thesis is to find out whether and how will the influence of vocal cords modulation be manifested on the dynamic stabilization of the standing body during translational shifts of the supporting surface of different intensities and A-P directions. Thus, building on the findings of Massery et al (2013). Methods: The thesis has the character of qualitative research. The experiment was attended by 23 healthy probands, of which 7 men and 16 women aged 20-40 years. Spirometry was used to test the objectivity of airway airflow during breathing / phoning maneuvers with different vocal cords positioning and dynamic computer posturography using the Neurocom Smart Equi Test System and its Motor Control Test, which evaluated the effectiveness of automatic postural responses. We connected the posturograph with the spirometer using the Kistler accelerometer (type 8766A100BB). The course of the experiment was simultaneously recorded by a camera (GoPro Hero 7). The Smart EquiTest System generated three postural perturbations of different intensity (S - sub treshold, M - threshold, L - saturating) in two directions (anterior translation / posterior translation). The measured data were then processed in the program Neurocom...
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FEM-basierte Modellierung stark anisotroper Hybridcord-Elastomer-Verbunde / FE-based modeling of strongly anisotropic hybrid cord-rubber composites

Donner, Hendrik 27 September 2017 (has links) (PDF)
Zur Analyse der Beanspruchungen in textilverstärkten Elastomerbauteilen wie Luftfedern, Reifen, Riemen und Schläuchen sind Berechnungsmodelle mit einer feinen Balance zwischen Genauigkeit und Effizienz erforderlich. Die großen Deformationen, stark anisotropen Struktureigenschaften und kleinen Abmessungen der Festigkeitsträger gegenüber denen des Bauteils bedürfen einerseits einer detaillierten Modellierung, andererseits sind die kritischen Bereiche in diesen Bauteilen räumlich stark begrenzt, sodass eine Reduktion des Berechnungsaufwands erstrebenswert ist. Diese Modellreduktion führt zu Simulationen mit geringer Rechenzeit, die für eine praxistaugliche Optimierung von Hybridcord-Elastomer-Verbunden unerlässlich sind. Die beiden Hauptschwerpunkte der vorliegenden Arbeit bilden die kontinuumsmechanische Modellierung von Hybridcorden und die Erstellung repräsentativer Volumenelemente hochbeanspruchter Hybridcord-Elastomer-Verbunde. Aufbauend auf einem anisotropen Plastizitätsmodell zur Erfassung der Reibung in Multifilamentgarnen stellt ein Finite-Elemente-Modell zur Simulation der Verzwirnung von Hybridcorden das Fundament der Arbeit dar. Anhand experimenteller Ergebnisse aus Zug- und Torsionsversuchen sowie einem Vergleich mit Querschnittsaufnahmen wird gezeigt, dass das Modell die komplexen Eigenschaften eines Hybridcords abbilden kann. Die Grundlage der repräsentativen Volumenelemente stellt eine Erweiterung der klassischen periodischen Randbedingungen dar, die eine Berücksichtigung von Krümmungen und Drucklasten ermöglicht. Das Modell eignet sich daher, die Beanspruchungen in den hochbelasteten Bereichen textilverstärkter Elastomerbauteile wie der Rollfalte einer Luftfeder effizient zu analysieren. Mittels Parameterstudien werden abschließend Hybridcorde und Hybridcord-Elastomer-Verbunde untersucht und einige Hinweise für eine optimale Gestaltung hinsichtlich minimaler Beanspruchungen des Elastomers, des Hybridcords sowie der Grenzfläche gegeben. / The analysis of stresses and strains within textile-reinforced rubber components like air springs, tyres, driving belts, and tubes requires accurate as well as efficient computational models. On the one hand, the large deformations, the composite's strongly anisotropic properties, and the large ratio between the size of the cords and the composite necessitate a precise modeling. On the other hand, the highly loaded parts of the components are spatially confined and thus a reduction of the computational effort is desirable. These reduced models are efficient enough for performing engineering-oriented optimizations. The two main priorities of this work are the continuum mechanical modeling of hybrid cords and the development of representative volume elements of highly loaded hybrid cord-rubber composites. Based on an anisotropic plasticity model, which takes the frictional sliding between the filaments within multifilament yarns into account, a finite element model for the simulation of the twisting process of a hybrid cord is the fundament of this work. A comparison with experimental results from tensile and torsional tests as well as images of cross sections validate the proposed hybrid cord model. The basis of the representative volume element is the extension of the classical periodic boundary conditions, which now enable to take the curvature and pressure load into account. Thus, the model is suitable to analyze the highly loaded parts of hybrid cord-rubber composites like the rolling lobe of an air spring. Finally, the set-ups of hybrid cords and hybrid cord-rubber composites are analyzed by means of parameter studies to obtain a minimized loading of the rubber, yarns, and their interface.

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