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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.
41

Modification et validation de la technique de l'anneau piézoélectrique pour mesurer la prise et le durcissement des matériaux à base de ciment / Modification and validation of piezoelectric ring actuator technique to monitor setting and hardening of cement-based materials

Soliman, Nancy Ahmed January 2010 (has links)
A period of cement hydration is one of critical in the life span of concrete structures. One of the reasons of collapse of concrete structural elements during and after construction is the error in determining the concrete characteristics at early age. Recently, non-destructive test emerged as a popular way to evaluate the properties of cement-based materials. This test offers continuous measurements of concrete properties as well as ability to monitor any changes in the current state of structural materials. In the existing research, some of these methods fail to capture well properties of the materials in the plastics stage. A new piezoelectric pulse testing device (Piezoelectric Ring Actuators Technique), (P-RAT ) was initially developed at the University of Sherbrook as a non-destructive test (NDT ) for soil. This technique is considered a completely new, versatile, advanced and accurate. The development of the new technique (P-RAT ) was done on two main bases: the first was the development of piezoelectric ring actuators set-up and the second is the development of the interpretation method. The setup is composed of two main units; emitter and receiver, and is capable of measuring shear and compression wave velocities in specimens. With this technique, many problems of pulse tests, which make interpretation of results difficult and ambiguous, were solved in soil. The P-RAT overcomes wave reflections at boundaries (end-caps and sides), sample disturbance, weak shear coupling between soil and device (interaction) as well as the fixation problems, low resonant frequency and limited input voltage of the existing device. The previous method is exploited forward to measure the hydration properties of cement-based material. To apply this test method, it is necessary to determine how the evolution of shear wave velocity can be related and sensitive to the hydration of cement-based materials. Validation of the P-RAT with four conventional test setups that can be used to monitor early setting and hydration of cement-based materials is carried out. These tests include penetration resistance to monitor initial and final setting respectively, calorimetric to monitor heat of hydration, electrical conductivity to monitor change in continuity of the pore structure and compressive strength at 24 hours. The phase one of this investigation included trial tests to investigate the possibility of employing the original setup used for soil (P-RAT ) to determine setting and hardening properties of cement-based material. Based on the results of the preliminary test, two modifications were conducted to the previous test device to fit with cement based material and to obtain adequate resonant frequency for cement-based materials. These modifications are the design of the container and changing the dimensions of the rings. The resultant version of P-RAT after the modification was referred to be as P-RAT2 . Calibration of the P-RAT2 with water specimen was undertaken using the compression wave velocity and resulted in 99.33% accuracy. One paste mixture was tested three times to determine the experimental error of the P-RAT2 . The repeatability carried out on the P-ART2 proved the ability of this setup to capture accurate results of the shear wave velocity. This relative error is limited to 9 %. A number of series of validation was performed on cement paste and mortar mixtures proportioned with various water cement ratios (w/cm ) as well as chemical admixtures. The w/cm ratio ranged between (0.35 and 0.50). The investigated chemical admixtures comprise of high-range water-reducing agent, viscosity-modifying agent, set-accelerating agent, and set-retarding agent. The presented validations examine the ability of a P-RAT2 to monitor the hydration of the cement-based materials. The hydration is characterized by setting time, heat of hydration, electrical conductivity, and compressive strength at 24 hours. The results obtained using the P-RAT2 was correlated to those obtained using the conventional tests and strength measurement. The results enable to validate the ability of P-RAT2 to accurately detect variations in the hydration of cement-based materials. In addition, the initial and final time of setting can be determined from the derivation of velocity vs. time curve. The results show that conductivity, resistivity, has a bilinear relationship to shear wave velocity. The compressive strength at 24 hours was correlated to both the shear wave velocity and shear modulus obtained using the P-RAT2 . Furthermore, analytical model was derived to estimate the w/cm in mortar mixture by measuring the shear wave velocity (V[subscript s] ) and the corresponding time (t )||Résumé : La période d'hydratation du ciment est l'une des périodes clé du cycle de vie des structures en béton. L'une des raisons de l'effondrement d'éléments structuraux en béton pendant et après la construction peut être attribuée à une détermination des caractéristiques au jeune âge erronée. Depuis quelques années, l’auscultation des structures est devenue une méthode très populaire pour évaluer les propriétés des matériaux cimentaires. Cette méthode permet d'obtenir les propriétés du béton en continue et possibilité un suivi de changements dans I'état des matériaux structuraux. Dans I'état actuel de la recherche dans ce domaine, certaines méthodes ne sont pas adéquates pour bien mesurer les propriétés des matériaux à I'état plastique. Un nouvel appareil d'essai à impulsions piezoélectriques (Piezoelectric Ring Actuators technique), (P-RAT) a initialement été développé à l’Université de Sherbrooke comme technique d'auscultation des sols. Cette technique est considérée complètement nouvelle, polyvalente, évoluée et précise. Le développement de cette nouvelle technique (P-RAT) a été effectué en deux volets : la première sole est le développement du dispositif de vérin de commande annulaire piezoélectrique et le deuxième est le développement d'une méthode d'interprétation. Le dispositif d'essai est composé de deux unités principales, un émetteur et un récepteur. Et permet de mesurer la vitesse de propagation des ondes de cisaillement et de compression. Grâce à cette technique, plusieurs des problèmes associés aux dispositifs d'essais par impulsion des ondes, qui rendent les résultats ambigus et difficiles à interpréter, ont été résolu pour les sols. Le dispositif P-RAT surmonte les problèmes de réflexion des ondes aux limites (embouts et côtés), la perturbation de l’échantillon, le couplage de cisaillement faible entre le sol et l'appareil (interaction) ainsi que les problèmes de fixation, la faible résonnance des fréquences et le voltage d'entrée limité du dispositif. La méthode décrite a été utilisée pour mesurer les propriétés d'hydratation des matériaux cimentaires. Pour pouvoir appliquer cette méthode, il faut déterminer comment l’évolution de la propagation des ondes de cisaillement peut être reliée à l'hydratation des matériaux cimentaires et être sensible à ces dernières. La validation de la méthode P-RAT est réalisée, à l'aide de quatre configurations conventionnelles que l’on peut utiliser pour faire le suivi de la prise et de l'hydratation des matériaux cimentaires. Ces essais consistent à la résistance à la pénétration afin de pouvoir déterminer la prise initiale et finale, la calorimétrie pour suivre l’evolution de la chaleur d'hydratation, la conductivité électrique pour effectuer le suivi de la structure des pores et la résistance à la compression à 24 heures. La phase 1 de l'étude comprend des essais pour évaluer la possibilité d'utiliser la configuration originale utilisée pour les sols (P-RAT) pour déterminer les propriétés de prise et de durcissement des matériaux cimentaires. Selon les résultats des essais préliminaires, deux modifications ont été effectuées à l'appareil original pour permettre son utilisation avec des matériaux cimentaires et pour obtenir une fréquence de résonnance raisonnable sur les matériaux cimentaires. Les modifications effectuées sont la conception du contenant et un changement de la dimension des anneaux. La version modifiée du P-RAT est designée P-RAT2. La calibration du P-RAT2 à l'aide d'échantillon liquide sous propagation d'ondes de compression a été menée, avec des résultats d'une précision de 99,33 %. Un mélange a été testé trois fois pour déterminer l'erreur expérimentale du P-RAT2. La répétitivité des essais sur le PART2 a démontré la capacité de cet appareil à produire des résultats de cisaillement de propagation des ondes de cisaillement très précis. L'erreur relative se limite à 9 %. Une série d'essais de validation a été menée sur des mélanges de pâte de ciment et de mortier de rapport eau/ciment variés (e/c) ainsi qu'avec des adjuvants. Le rapport e/c variait entre 0,35 et 0,50. Les adjuvants utilisés étaient des supers plastiflants (réducteur d'eau), des agents de viscosité, des agents accélérateurs de prise et des agents retardateurs de prise. Les validations présentées ont pour but de valider la capacité du P-RAT2 à suivre l'hydratation des matériaux cimentaires. L'hydratation est caractérisée par le temps de prise, la chaleur d'hydratation, la conductivité électrique et la résistance à la compression à 24 heures. Les résultats obtenus à l'aide du P-RAT2 ont été comparés à ceux obtenus à l'aide d'essais de mesure des caractéristiques physiques et de résistance traditionnels. Ces résultats permettent de valider la capacité du P-RAT2 à détecter avec précision les variations dans l'hydratation des matériaux cimentaires. De plus, le dispositif P-RAT2 peut avoir une correction avec mesure obteniez avec les appareils traditionnels. II est aussi possible de déterminer le temps de prise initial et final à l'aide d'une courbe de propagation vs le temps. Les résultats montrent que la conductivité et la résistivité ont une relation bilinéaire à la propagation des ondes de cisaillement. La résistance à la compression à 24 heures a été comparee à la fois à la propagation des ondes de cisaillement et au module de cisaillement obtenus avec le P-RAT2. De plus, un modèle analytique a été établi pour estimer le rapport e/c dans le mélange de mortier en mesurant la propagation des ondes de cisaillement (V) correspondant au temps (t).
42

Screening for abnormal heart sounds and murmurs by implementing neural networks

Visagie, Claude 03 1900 (has links)
Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2007. / This thesis is concerned with the testing of an “auscultation jacket” as a means of recording heart sounds and electrocardiography (ECG) data from patients. A classification system based on Neural Networks, that is able to discriminate between normal and abnormal heart sounds and murmurs, has also been developed . The classification system uses the recorded data as training and testing data. This classification system is proposed to serve as an aid to physicians in diagnosing patients with cardiac abnormalities. Seventeen normal participants and 14 participants that suffer from valve-related heart disease have been recorded with the jacket. The “auscultation jacket” shows great promise as a wearable health monitoring aid for application in rural areas and in the telemedicine industry. The Neural Network classification system is able to differentiate between normal and abnormal heart sounds with a sensitivity of 85.7% and a specificity of 94.1%.
43

Autonomous auscultation of the human heart

Botha, J. S. F. 03 1900 (has links)
Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The research presented in this thesis serves to provide a tool to autonomously screen for cardiovascular disease in the rural areas of Africa. Vital information thus obtained from patients can be communicated to advanced medical centres by Telemedicine. Cardiovascular disease is then detected in its initial stages, which is essential to its effective treatment. The system developed in this study uses recorded heart sounds and electrocardiogram signals to distinguish between normal and abnormal heart conditions. This system improves on standard diagnostic tools in that it does not require cumbersome and expensive imaging equipment or a highly trained operator. Heart sound- and electrocardiogram signals from 62 volunteers were recorded with the prototype Precordialcardiogram device as part of a clinical study to aid in the development of the autonomous auscultation software and to screen patients for cardiovascular disease. These volunteers consisted of 28 patients of Tygerberg Hospital with cardiovascular disease and, for control purposes, 34 persons with normal heart conditions. The autonomous auscultation system developed during this study, interprets data obtained with the Precordialcardiogram device to autonomously acquire a normal or abnormal diagnosis. The system employs wavelet soft thresholding to denoise the recorded signals, followed by the segmentation of heart sound by identifying peaks in the electrocardiogram. Novel frequency spectral information was extracted as features from the heart sounds, by means of ensemble empirical mode decomposition and auto regressive modelling. These features proved to be particularly significant and played a major role in the screening capability of the system. New time domain based features were identified, established on the specific characteristics of the various cardiovascular diseases encountered during the study. These features were extracted via the energy ratios between different parts of ventricular systole and diastole of each recorded cardiac cycle. The respective features were classified to characterise typical heart diseases as well as healthy hearts with an ensemble artificial neural network. Herein the decisions of all the members were combined to obtain a final diagnosis. The performance of the autonomous auscultation system used in concert with the Precordialcardiogram device prototype, as determined through the leave-one-out crossvalidation method, had a sensitivity rating of 82% and a specificity rating of 88%. These results demonstrate the potential benefit of the Precordialcardiogram device and the developed autonomous auscultation software in a Telemedicine environment. / AFRIKAANSE OPSOMMING: Hierdie tesis beskryf die navorsing van 'n outonome toetsing en sifting stelsel vir kardiovaskulêre siektes in landelike dele van Afrika, vanwaar mediese inligting per telefoon versend kan word. Die apparaat maak vroeë opsporing van kardiovaskulêre siektes moontlik, wat essensieel is vir effektiewe behandeling daarvan en ook die koste-effek van hierdie siektes verminder. In die huidige ontwikkelde stelsel word normale sowel as abnormale hart-toestande getipeer met opnames van hartklanke sowel as elektrokardiogram-seine. Voordele wat hierdie stelsel bo standaard diagnostiese metodes het, sluit die hanteerbare formaat van die hele apparaat sowel as die nie-noodsaaklikheid van duur beeldskeppende apparaat, of hoogs opgeleide personeel. Hartklank- en elektrokardiogramseine van 62 vrywilligers is met die prototipe "Precordialcardiogram" apparaat opgeneem om by te dra tot die ontwikkeling van die rekenaar sagteware vir die outonome auscultatsie stelsel en om die pasiëntsiftingsvermoë daarvan te toets. Die vrywilligers het 28 pasiënte van Tygerberg hospitaal met abnormale harttoestande ingesluit, sowel as ‘n kontrolegroep van 34 persone met normale harttoestande. Die outonome auskultasie-stelsel wat tot stand gekom het deur hierdie ondersoek maak gebruik van “wavelet” sagte drempeling om geraas uit die opgeneemde seine te verwyder. Daarna word die hartklanke gesegmenteer deur die pieke van die elektrokardiogram te identifiseer. Deur middel van "ensemble empirical mode decomposition" en outoregressiewe modellering, is nuwe inligting aangaande die frekwensie spektra van hartklanke, aanwysend van spesifieke harttoestande, verkry. Die beduidendheid van hierdie eienskappe is bewys en het 'n belangrike rol in die siftingsvermoë van die stelsel gespeel. Hierbenewens is nuwe tyd-gebaseerde eienskappe van die onderskeie kardiovaskulêre siektes wat tydens die ondersoek bestudeer is, geïdentifiseer. Hierdie eienskappe is geëien deur die energie-verhoudings tussen verskillende dele van die ventrikulêre sistolie en diastolie van elke opgeneemde hartsiklus te ontleed. 'n "Ensemble artificial neural network" is gebruik om die geïdentifiseerde eienskappe van hartsiektes sowel as normale harttoestande, te klassifiseer. Hierin is besluite van al die lede van die netwerk gekombineer, ten einde ‘n finale diagnose te maak. Die klassifiseerder se geldigheid is kruis-bevestig deur middel van die laat-een-uit kruisbevestigings-metode. Deur middel van die kruis-bevestigingsmetode is die bedryfsvermoëns van die outonome auskultasie-stelsel, toegerus met die "Precordialcardiogram" apparaat, repektiewelik op 82% vir sensitiwiteit en 88% vir spesifisiteit vasgestel. Hierdie resultate demonstreer die benuttingspotensiaal van die apparaat in 'n Telemedisyne omgewing.
44

Application of laser doppler vibrocardiography for human heart auscultation

Koegelenberg, Suretha 04 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: This thesis investigates the feasibility of the laser Doppler vibrometer (LDV) for use in the autonomous auscultation of the human heart. As a non-contact measurement device, the LDV could become a very versatile biomedical sensor. LDV, stethoscope, piezoelectric accelerometer (PA) and electrocardiogram (ECG) signals were simultaneously recorded from 20 volunteers at Tygerberg Hospital. Of the 20 volunteers, 17 were confirmed to have cardiovascular disease. 3 patients with normal heart sounds were recorded for control data. The recorded data was successfully denoised using soft threshold wavelet denoising and ensemble empirical mode decomposition. The LDV was compared to the PA in common biomedical applications and found to be equally accurate. The heart sound cycles for each participant were segmented using a combination of ECG data and a simplicity curve. Frequency domain features were extracted from each heart cycle and input into a k-nearest neighbours classifier. It was concluded that the LDV can form part of an autonomous, non-contact auscultation system. / AFRIKAANSE OPSOMMING: Hierdie tesis ondersoek die haalbaarheid daarvan om die laser Doppler vibrasiemeter (LDV) vir die outonome beluistering van die menslike hart te gebruik. As 'n kontaklose meettoestel kan die LDV werklik 'n veelsydige biomediese sensor word. Twintig vrywilligers by die Tygerberg Hospitaal se LDV-, stetoskoop-, piësoelektriese versnellingsmeter (PV)- en elektrokardiogram (EKG) seine is gelyktydig opgeneem. Uit die 20 vrywilligers was daar 17 bevestigde gevalle van kardiovaskulêre siektes. Die data van drie pasiënte met normale hartklanke is as kontroledata opgeneem. Geraas is suksesvol uit die opgeneemde data verwyder deur 'n kombinasie van sagtedrempelgolf en saamgestelde empiriese modus ontladingstegnieke. Die LDV was vergelyk met die PV vir algemene biomediese gebruike en daar was gevind dat dit vergelykbare akkuraatheid het. Die hartklanksiklusse van elke deelnemer is gesegmenteer deur EKG data en 'n eenvoudskromme te kombineer. Frekwensiegebiedskenmerke is uit elke hartsiklus onttrek en in 'n k-naastebuurpunt klassifiseerder ingevoer. Daar is tot die gevolgtrekking gekom dat die LDV deel van 'n outonome, kontaklose beluisteringstelsel kan uitmaak.
45

Disfagia em cardiopatas idosos: teste combinado de deglutição e monitorização dos sinais vitais / Dysphagia in older people with heart diseases: a combined vital sign monitoring and swallowing test

Dantas, Mara de Oliveira Rodrigues Luiz 12 August 2008 (has links)
Disfagia orofaríngea ocorre em pacientes após cirurgias cardíacas e prolonga o tempo de internação. O objetivo da presente Tese foi identificar as características da deglutição nos cardiopatas idosos indicados à cirurgia de Revascularização Miocárdica. Foi utilizado um protocolo combinado de deglutição de água, ausculta cervical e monitorização dos sinais vitais. O registro da freqüência cardíaca e da saturação de oxigênio (FC e SpO2) foi realizado com oxímetro de pulso antes, durante e após o teste de deglutição de água com 1,3,5,10, 15 e 20 ml. A ausculta cervical foi realizada com estetoscópio eletrônico para a análise do número, tempo de resposta e classificação do som da deglutição. Foram registradas a freqüência respiratória (FR) e a presença de tosse e engasgo. Os resultados foram analisados através de dois estudos. O primeiro avaliou 60 idosos saudáveis, sendo 45 mulheres e 11 homens, com média de idade de 74,5 anos. Os resultados mostraram aumento da FC durante o teste e diminuição logo após. Houve aumento de SpO2 e FR após o teste. Houve deglutição única em todas as medidas exceto em 20 ml. O tempo de resposta da deglutição em todos os volumes foi menor que 1 segundo exceto em 1 e 3 ml. A ausência de tosses e engasgos foi predominante. O som do tipo 3 predominou em todos os volumes exceto em 20 ml onde predominou o som do tipo 1. Concluindo, as características da deglutição dos idosos saudáveis representaram alterações compatíveis com as mudanças fisiológicas decorrentes da idade e não evidenciaram a disfagia. No segundo estudo, 38 idosos com doença arterial coronária constituíram o Grupo de Pesquisa (GP) e foram comparados a 30 idosos saudáveis no Grupo Controle (GC). Foram avaliados 27 homens e 11 mulheres no GP, com média de idade de 68 anos. No GC foram avaliados 15 homens e 15 mulheres, com idade média de 70 anos. Houve diferença significativa no tempo de resposta da deglutição nos cardiopatas com FC abaixo de 60 , sendo mais curto em 3 ml, 10 ml, 15 ml e 20 ml. A FC permaneceu mais baixa nos cardiopatas. Não houve diferença significativa nos outros parâmetros, ou seja, os idosos cardiopatas foram semelhantes aos idosos saudáveis, exceto pelo tempo curto para a resposta da deglutição. Concluindo, a presente pesquisa mostrou que os idosos cardiopatas apresentam diferença na função de deglutição em relação aos idosos saudáveis. Os cardiopatas apresentam alterações da coordenação temporal entre respiração e deglutição, revelando risco para a disfagia. As técnicas de ausculta cervical e oximetria de pulso favoreceram a análise objetiva desses dados. / Oropharyngeal dysphagia affects patients after heart surgery and increases the length of the hospitalization. The objective of the present research was to identify the swallowing function caractheristics of aged people with heart diseases who were referred to the coronary artery surgery. A combined protocol of sign vital monitoring and water swallowing evaluation was used together with cervical auscultation. The heart rate (HR) and oxygen saturation (SpO2) were recorded by pulse oximetry before, during and after the water test for 1,3,5,10,15 and 20 ml. Cervical auscultation was done by electronic stethoscope in order to analyse the number, time of swallowing response and swallowing sound classification. Respiration rate (RR), cough and choking were recorded. The results were analysed by two studies. In the first one, sixty healthy aged individuals were assessed. There were 45 women and 11 men; mean age was 74,5 years. There were SpO2 and RR increasing after the water test. There were single swallow for all volume except 20 ml. The time of swallowing response for all volumes occurred before 1 second except for 1 and 3 ml. Cough and choking were not predominant in the water test. The type 3 sound was predominant for all volumes except 20ml where there was type 1 sound. In summary, the characteristics of swallowing in healthy aged individuals represented alterations due to physiological changes in aging and there was no evidence of dysphagia. In the second study, 38 aged subjects with coronary artery disease composed the research group (RG) and they were compared to 30 healthy aged subjects in the control group (CG). There were 27 men and 11 women assessed in the RG; mean age was 68 years. There were 15 women and 15 men assessed in the CG, mean age was 70 years. There was significant difference in the time of swallowing response in the RG when HR was below 60. It was shorter for 3, 10, 15 and 20 ml. HR was minor in heart disease individuals. There were no significant difference in other parameter, that is, aged patients with heart disease were similar to healthy aged individuals, except for the short time of swallowing response. Therefore, the present study presented a different swallowing function between aged patients with heart disease and healthy aged individuals. The heart disease patients have alterations in the temporal coordination between swallowing and respiration function, disclosing risk of dysphagia. Cervical auscultation and pulse oximetry were advantageous for the objective analysis of the data.
46

Avaliação da coordenação sucção/deglutição/respiração através da ausculta cervical digital em recém-nascidos pré-termo e a termo

Silva, Caroline Silveira da January 2013 (has links)
Introdução: Recém- nascidos a termo nascem com a habilidade de coordenar as funções de sucção- deglutição- respiração. Recém-nascidos pré-termo não apresentam essa habilidade, consequentemente, necessitam de alimentação por sonda e podem apresentar dificuldade na transição da alimentação por sonda para via oral. O objetivo desse estudo foi comparar o padrão de coordenação sucção-deglutição-respiração de recém-nascidos a termo em aleitamento materno exclusivo e recém-nascidos pré-termo na transição da alimentação por sonda para a via oral com mamadeira. Métodos: Foram avaliados 64 recém-nascidos (32 recém-nascidos pré-termo e 32 recém-nascidos a termo) internados na UTI Neonatal e Alojamento Conjunto do Hospital Fêmina de Porto Alegre. Os recém-nascidos a termo foram avaliados durante as primeiras 48horas de vida e os recém-nascidos pré-termo foram avaliados no início da alimentação por via oral após período de alimentação por sonda orogástrica. O equipamento utilizado na ausculta cervical digital era composto por um detector acústico e por um pré-amplificador com filtro conectados a um computador Coreo 2 Duo. O microfone foi fixado com fita adesiva no pescoço do recém-nascido para captar os sinais da sucção/deglutição durante a alimentação. Três sinais de 30 segundos foram obtidos de cada RN e uma média foi obtida para os seguintes parâmetros: total de “suck-swallow signal” (SSS); duração total dos SSS; total de pausas para respirar >2,5 segundos; duração total das pausas. Os dados dos sinais dos sons da deglutição gravados foram analisados visual e auditivamente pelo Software Raven versão 1.1 Resultados: Os resultados mostraram que houve diferença estatisticamente significante para o parâmetro “duração total dos SSS”, mostrando que o tempo envolvido na sucção/deglutição é maior para os recém-nascidos pré-termo. Em relação ao parâmetro “duração total das pausas”, observou-se um tempo maior para os recém-nascidos a termo. O parâmetro “número de pausas” que indica a quantidade de momentos que o recém-nascido apresenta pausa para respirar durante a mamada no período de gravação também foi significativamente maior para os recém-nascidos a termo em comparação aos recém-nascidos pré-termo. Conclusão: Demonstramos que a ausculta cervical digital é um exame de fácil execução e minimamente invasivo na avaliação da coordenação sucção-deglutição-respiração em recém-nascidos a termo e pré-termo. Os recém-nascidos a termo com aleitamento materno durante os primeiros dias de vida apresentaram pausas para respirar mais prolongadas durante o processo de sucção-deglutiçãorespiração em comparação aos recém-nascidos pré-termo. Isso pode refletir o estágio do desenvolvimento do padrão de maturidade de processo de deglutição. / Background: Fullterm newborn are born with the ability to coordinate the functions of sucking, swallowing and breathing. Preterm infants may not have this ability, therefore, may require tube feeding and may have difficulty in the transition from tube feeding to oral feeding. The aim of this study was to compare the coordination pattern of suck, swallow and breathing in fullterm newborn exclusively breastfed and preterm newborn at the transition from tube feeding to oral bottle feeding . Methods: 64 newborn (32 preterm and 32 fullterm) admitted to the Neonatal Intensive Care Unit and Rooming-in of Femina Hospital of Porto Alegre. Fullterms were evaluated during the first 48 hours of life and preterms were assessed at the beginning of oral feeding after feeding period by orogastric tube. The equipment used in digital cervical auscultation included an acoustic detector and a preamplifier with filter connected to a computer 2 Duo Core. The microphone was fixed with tape on the neck of the newborn to capture the signals of suck / swallow during feeding. Three signals of 30 seconds were obtained from each newborn and an average was obtained for the following parameters: total number of "suck-swallow signal" (SSS); total duration of the SSS; total number of pauses> 2.5 seconds and total duration of pauses and . Signs of swallowing sounds recorded were analyzed visually and audibly by Raven Software version 1.1 Results: The results showed statistically significant differences for the parameter "total duration of the SSS," showing that the time involved in suction / swallowing is greater for preterms. As for the parameter "total duration of pauses," there was more time spent by fullterms. The parameter "number of pauses" that indicates the amount of times that newborn have respiratory pause during feeding in the recording period was also significantly higher for fullterms when compared with preterms. Conclusion: We demonstrated that digital cervical auscultation is a minimally invasive, feasible, and easy-to-perfom tool for evaluation of suck-swallowbreathing coordination in newborn. The fullterm infants with breastfeeding within the first days of life had prolonged respiratory pauses during the process of sucking, swallowing and breathing compared to preterms. This may reflect the stage of development of the natural maturity process of swallowing.
47

Modeling and methods of biomechanical heart signals processing using the conditional cyclic random process / Modélisation et méthodes de traitement des signaux biomécaniques cardiaques en utilisant le processus conditionnel cyclique aléatoire

Lutsyk, Nadiia 20 September 2016 (has links)
Ce travail a été réalisé en cotutelle entre l'Université Nationale de Technologie de Ternopil Ivan Pul'uj (TNTU, Ukraine) et l’Université Blaise Pascal (France). Il appartient au domaine scientifique de la biomécanique et de l'informatique. Le but de l'étude est de développer les modèles et les méthodes de traitement des signaux biomécaniques cardiaques par les systèmes de diagnostic assisté par ordinateur avec une précision accrue, informativité et de la complexité de calcul inférieure. La méthode d'analyse statistique du rythme cardiaque a été mise au point. Cette méthode possède une plus grande précision et informativité par rapport aux méthodes connues d'analyse du rythme cardiaque. Dans cette thèse, le logiciel existant de l'analyse des signaux cardiaques biomécaniques a été améliorée par l'ajout de nouveaux modules logiciels, qui mettent en œuvre les nouvelles méthodes de l'analyse du rythme cardiaque et de l'analyse morphologique des signaux cardiaques biomécaniques. / This work has been performed under the co-tutelle agreement between Ternopil Ivan Pul’uj National Technical University in Ternopil (TNTU, Ukraine) and the University Blaise Pascal in Clermont-Ferrand (France). It belongs to the scientific field of biomechanics and informatics. The aim of the study is to develop the mathematical models and methods of the processing of biomechanical heart signals in computer-based diagnostic systems with increased accuracy, informativeness and lower computational complexity. The method of statistical analysis of heart rhythm was developed, which is characterised by higher accuracy and informativeness compared with the known methods of heart rhythm analysis. In this thesis, the existing software of the analysis of biomechanical heart signals was improved by means of adding new software modules that implement the new methods of the analysis of heart rhythm and morphologic analysis of biomechanical heart signals.
48

Nouvelles utilisations des mesures de bassins de déflexion pour caractériser l’état structurel des chaussées / New uses of deflection bowls measurements to characterize the structural conditions of pavements

Le Boursicaud, Vinciane 08 November 2018 (has links)
L’évaluation des caractéristiques structurelles des chaussées permet l’optimisation de leur maintenance. La mesure de déflexion est une mesure de base de cette évaluation. Aujourd’hui,seuls la déflexion maximale et le rayon de courbures ont analysés. Pourtant, le curviamètre et le déflectographe relèvent le bassin de déflexion complet dont l’analyse permettrait d’extraire des paramètres plus sensibles à l’endommagement des chaussées. Actuellement, l’interprétation des mesures est seulement qualitative et aucun calcul inverse de l’état de dommage de la structure n’est réalisé. La thèse vise à améliorer l’interprétation des mesures de déflexion. Le fonctionnement des appareils a montré que leurs hypothèses de mesure conduisent à des biais de mesure. Pour pallier ce problème, une procédure de correction des mesures a été mise en place. La comparaison avec des bassins théoriques a montré que la méthode de correction était satisfaisante. Ensuite, une étude numérique visant à déterminer la sensibilité du bassin de déflexion à la présence de différents défauts a été conduite. Celle ci a montré que les indicateurs classiques de la mesure de déflexion étaient peu sensibles à un endommagement dans la chaussée. Une méthodologie a donc été développée pour la création d’indicateurs optimisés à un type de défauts spécifiques. L’étude sur cas théoriques a conduit à l’obtention de résultats concluants. L’ensemble de ces travaux a ensuite été validé sur sites expérimentaux pour des mesures de répétabilité, mais également sur site avec la présence avérée de défauts. Finalement, la thèse a envisagé l’utilisation des travaux précédents sur des mesures réelles recueillies sur itinéraire. / The evaluation of the structural characteristics of pavements is involved in their maintenance. The measurement of deflection is a key indicator of this evaluation. Currently, only the maximum deflection and the radius of curvature are analyzed. However, the curviameter and the deflectograph are able to record the whole deflection bowl and the parameters deduced from thismeasurement could help to better characterized damages on pavements. The interpretation of the measurements is only qualitative and back calculation of pavement layer moduli gives unsatisfactory results. The thesis aims to improve the interpretation of deflection measurements. The working principle of these apparatus and the measurement assumptions introduce several measurement biases.To overcome these issues, a correction process has been developed. The comparison with theoretical basins has given satisfactory results on bituminous or flexible pavements. Then, a numerical study has been conducted to determine the influence of pavements damages on the deflection measurement. By this study, it has been showed that the usual indicators of the deflection measurement are notable to detect all damages. So, a methodology hasbeen developed in order to create an optimized indicator specified to a special defect. A study on numerical results has been conducted to validate the implementation of these indicators. Then, the correction method and these new indicators have been tested on experimental sites with and without damages. At last, the research works have been studied at network level.
49

Avaliação da coordenação sucção/deglutição/respiração através da ausculta cervical digital em recém-nascidos pré-termo e a termo

Silva, Caroline Silveira da January 2013 (has links)
Introdução: Recém- nascidos a termo nascem com a habilidade de coordenar as funções de sucção- deglutição- respiração. Recém-nascidos pré-termo não apresentam essa habilidade, consequentemente, necessitam de alimentação por sonda e podem apresentar dificuldade na transição da alimentação por sonda para via oral. O objetivo desse estudo foi comparar o padrão de coordenação sucção-deglutição-respiração de recém-nascidos a termo em aleitamento materno exclusivo e recém-nascidos pré-termo na transição da alimentação por sonda para a via oral com mamadeira. Métodos: Foram avaliados 64 recém-nascidos (32 recém-nascidos pré-termo e 32 recém-nascidos a termo) internados na UTI Neonatal e Alojamento Conjunto do Hospital Fêmina de Porto Alegre. Os recém-nascidos a termo foram avaliados durante as primeiras 48horas de vida e os recém-nascidos pré-termo foram avaliados no início da alimentação por via oral após período de alimentação por sonda orogástrica. O equipamento utilizado na ausculta cervical digital era composto por um detector acústico e por um pré-amplificador com filtro conectados a um computador Coreo 2 Duo. O microfone foi fixado com fita adesiva no pescoço do recém-nascido para captar os sinais da sucção/deglutição durante a alimentação. Três sinais de 30 segundos foram obtidos de cada RN e uma média foi obtida para os seguintes parâmetros: total de “suck-swallow signal” (SSS); duração total dos SSS; total de pausas para respirar >2,5 segundos; duração total das pausas. Os dados dos sinais dos sons da deglutição gravados foram analisados visual e auditivamente pelo Software Raven versão 1.1 Resultados: Os resultados mostraram que houve diferença estatisticamente significante para o parâmetro “duração total dos SSS”, mostrando que o tempo envolvido na sucção/deglutição é maior para os recém-nascidos pré-termo. Em relação ao parâmetro “duração total das pausas”, observou-se um tempo maior para os recém-nascidos a termo. O parâmetro “número de pausas” que indica a quantidade de momentos que o recém-nascido apresenta pausa para respirar durante a mamada no período de gravação também foi significativamente maior para os recém-nascidos a termo em comparação aos recém-nascidos pré-termo. Conclusão: Demonstramos que a ausculta cervical digital é um exame de fácil execução e minimamente invasivo na avaliação da coordenação sucção-deglutição-respiração em recém-nascidos a termo e pré-termo. Os recém-nascidos a termo com aleitamento materno durante os primeiros dias de vida apresentaram pausas para respirar mais prolongadas durante o processo de sucção-deglutiçãorespiração em comparação aos recém-nascidos pré-termo. Isso pode refletir o estágio do desenvolvimento do padrão de maturidade de processo de deglutição. / Background: Fullterm newborn are born with the ability to coordinate the functions of sucking, swallowing and breathing. Preterm infants may not have this ability, therefore, may require tube feeding and may have difficulty in the transition from tube feeding to oral feeding. The aim of this study was to compare the coordination pattern of suck, swallow and breathing in fullterm newborn exclusively breastfed and preterm newborn at the transition from tube feeding to oral bottle feeding . Methods: 64 newborn (32 preterm and 32 fullterm) admitted to the Neonatal Intensive Care Unit and Rooming-in of Femina Hospital of Porto Alegre. Fullterms were evaluated during the first 48 hours of life and preterms were assessed at the beginning of oral feeding after feeding period by orogastric tube. The equipment used in digital cervical auscultation included an acoustic detector and a preamplifier with filter connected to a computer 2 Duo Core. The microphone was fixed with tape on the neck of the newborn to capture the signals of suck / swallow during feeding. Three signals of 30 seconds were obtained from each newborn and an average was obtained for the following parameters: total number of "suck-swallow signal" (SSS); total duration of the SSS; total number of pauses> 2.5 seconds and total duration of pauses and . Signs of swallowing sounds recorded were analyzed visually and audibly by Raven Software version 1.1 Results: The results showed statistically significant differences for the parameter "total duration of the SSS," showing that the time involved in suction / swallowing is greater for preterms. As for the parameter "total duration of pauses," there was more time spent by fullterms. The parameter "number of pauses" that indicates the amount of times that newborn have respiratory pause during feeding in the recording period was also significantly higher for fullterms when compared with preterms. Conclusion: We demonstrated that digital cervical auscultation is a minimally invasive, feasible, and easy-to-perfom tool for evaluation of suck-swallowbreathing coordination in newborn. The fullterm infants with breastfeeding within the first days of life had prolonged respiratory pauses during the process of sucking, swallowing and breathing compared to preterms. This may reflect the stage of development of the natural maturity process of swallowing.
50

Disfagia em cardiopatas idosos: teste combinado de deglutição e monitorização dos sinais vitais / Dysphagia in older people with heart diseases: a combined vital sign monitoring and swallowing test

Mara de Oliveira Rodrigues Luiz Dantas 12 August 2008 (has links)
Disfagia orofaríngea ocorre em pacientes após cirurgias cardíacas e prolonga o tempo de internação. O objetivo da presente Tese foi identificar as características da deglutição nos cardiopatas idosos indicados à cirurgia de Revascularização Miocárdica. Foi utilizado um protocolo combinado de deglutição de água, ausculta cervical e monitorização dos sinais vitais. O registro da freqüência cardíaca e da saturação de oxigênio (FC e SpO2) foi realizado com oxímetro de pulso antes, durante e após o teste de deglutição de água com 1,3,5,10, 15 e 20 ml. A ausculta cervical foi realizada com estetoscópio eletrônico para a análise do número, tempo de resposta e classificação do som da deglutição. Foram registradas a freqüência respiratória (FR) e a presença de tosse e engasgo. Os resultados foram analisados através de dois estudos. O primeiro avaliou 60 idosos saudáveis, sendo 45 mulheres e 11 homens, com média de idade de 74,5 anos. Os resultados mostraram aumento da FC durante o teste e diminuição logo após. Houve aumento de SpO2 e FR após o teste. Houve deglutição única em todas as medidas exceto em 20 ml. O tempo de resposta da deglutição em todos os volumes foi menor que 1 segundo exceto em 1 e 3 ml. A ausência de tosses e engasgos foi predominante. O som do tipo 3 predominou em todos os volumes exceto em 20 ml onde predominou o som do tipo 1. Concluindo, as características da deglutição dos idosos saudáveis representaram alterações compatíveis com as mudanças fisiológicas decorrentes da idade e não evidenciaram a disfagia. No segundo estudo, 38 idosos com doença arterial coronária constituíram o Grupo de Pesquisa (GP) e foram comparados a 30 idosos saudáveis no Grupo Controle (GC). Foram avaliados 27 homens e 11 mulheres no GP, com média de idade de 68 anos. No GC foram avaliados 15 homens e 15 mulheres, com idade média de 70 anos. Houve diferença significativa no tempo de resposta da deglutição nos cardiopatas com FC abaixo de 60 , sendo mais curto em 3 ml, 10 ml, 15 ml e 20 ml. A FC permaneceu mais baixa nos cardiopatas. Não houve diferença significativa nos outros parâmetros, ou seja, os idosos cardiopatas foram semelhantes aos idosos saudáveis, exceto pelo tempo curto para a resposta da deglutição. Concluindo, a presente pesquisa mostrou que os idosos cardiopatas apresentam diferença na função de deglutição em relação aos idosos saudáveis. Os cardiopatas apresentam alterações da coordenação temporal entre respiração e deglutição, revelando risco para a disfagia. As técnicas de ausculta cervical e oximetria de pulso favoreceram a análise objetiva desses dados. / Oropharyngeal dysphagia affects patients after heart surgery and increases the length of the hospitalization. The objective of the present research was to identify the swallowing function caractheristics of aged people with heart diseases who were referred to the coronary artery surgery. A combined protocol of sign vital monitoring and water swallowing evaluation was used together with cervical auscultation. The heart rate (HR) and oxygen saturation (SpO2) were recorded by pulse oximetry before, during and after the water test for 1,3,5,10,15 and 20 ml. Cervical auscultation was done by electronic stethoscope in order to analyse the number, time of swallowing response and swallowing sound classification. Respiration rate (RR), cough and choking were recorded. The results were analysed by two studies. In the first one, sixty healthy aged individuals were assessed. There were 45 women and 11 men; mean age was 74,5 years. There were SpO2 and RR increasing after the water test. There were single swallow for all volume except 20 ml. The time of swallowing response for all volumes occurred before 1 second except for 1 and 3 ml. Cough and choking were not predominant in the water test. The type 3 sound was predominant for all volumes except 20ml where there was type 1 sound. In summary, the characteristics of swallowing in healthy aged individuals represented alterations due to physiological changes in aging and there was no evidence of dysphagia. In the second study, 38 aged subjects with coronary artery disease composed the research group (RG) and they were compared to 30 healthy aged subjects in the control group (CG). There were 27 men and 11 women assessed in the RG; mean age was 68 years. There were 15 women and 15 men assessed in the CG, mean age was 70 years. There was significant difference in the time of swallowing response in the RG when HR was below 60. It was shorter for 3, 10, 15 and 20 ml. HR was minor in heart disease individuals. There were no significant difference in other parameter, that is, aged patients with heart disease were similar to healthy aged individuals, except for the short time of swallowing response. Therefore, the present study presented a different swallowing function between aged patients with heart disease and healthy aged individuals. The heart disease patients have alterations in the temporal coordination between swallowing and respiration function, disclosing risk of dysphagia. Cervical auscultation and pulse oximetry were advantageous for the objective analysis of the data.

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