No description available.

Made available in DSpace on 2014-06-11T19:28:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-10Bitstream added on 2014-06-13T20:37:41Z : No. of bitstreams: 1 cunha_mgs_me_guara.pdf: 2546988 bytes, checksum: 7f90dfedf806a463275bbea800769557 (MD5) / O presente trabalho consiste no estudo do comportamento do fluxo sangüíneo na artéria braquial, através de sinais captados por um microfone acoplado no estetoscópio e utilizado para transformar o sinal acústico (sonoro) em elétrico, e enviá-lo para o computador. O estudo foi realizado oferecendo-se diferentes pressões no esfigmomanômetro, o qual foi adaptado com dois manômetros. Um dos manômetros, graduado em mmHg, não foi modificado, possui o selo do INMETRO e atuou como referência, ao outro foi inserido um extensômetro, que transformou o sinal de pressão em sinal elétrico, utilizando uma ponte amplificada, enviando-o para uma placa de aquisição de dados no computador. Foi traçada uma curva de calibração do sinal elétrico (em mV) com relação ao manômetro graduado em mmHg. Foi proposto um protocolo para aquisição destes sinais a serem analisados, baseado em protocolos de aferição de pressão arterial. O comportamento do fluxo sangüíneo foi comparado às diferentes pressões exercidas pelo esfigmomanômetro. Ao analisar estes dados, foram propostos limites de normalidades da intensidade do sinal do fluxo sangüíneo em diferentes freqüências nas cinco fases da escala de Koroktov. O trabalho mostrou também os limites de normalidade da pressão arterial, utilizando-se o sinal adquirido pela extensometria. Finalmente, foi oferecido mais um auxílio no diagnóstico de patologias do sistema cardiovascular. / The present work consists to study the features of blood flow in to the brachial artery through signals detected by a microphone coupled together a stethoscope. This apparatus changes the acoustics in eletric signal and, then, sends to the computer. This study was implemented exhibiting different pressures in the sphygnomanometer, where two manometers, graded in mmHg, were coulpled. One that has the INMETRO certificate of gauging instruments was not modificate and, then, it was used as the standard. In the other, an extensometer was coupled together, which through an amplifier bridge, pressure signals are transformed in electric signals and sent to a data adapter unit connected to the computer. A gauging curve for the eletric signals versus pressure signals was ploted. It was proposed a protocol to adquire these data signals, based on the protocol of brachial pressure measurement. The features of blood flow were compared at different sphygnomanometer pressures. In the analysis process of the data, normality boundaries of intensity were proposed to the blood flow signal at different frequencies in the five phases of the Koroktov scale. The work also showed the normality boundaries of brachial pressure using the data signals adquired by the extensometry process. Finally, it was provided an one more aid in to diagnose pathologies in the cardiovascular system.

Made available in DSpace on 2014-06-11T19:34:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-11-30Bitstream added on 2014-06-13T20:05:58Z : No. of bitstreams: 1 cunha_mgs_dr_guara.pdf: 2456684 bytes, checksum: 35c3e64f73a4469232f7849a6e313dfa (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os músculos estriados esqueléticos, através de suas propriedades de contratilidade, extensibilidade e elasticidade, formam o principal motor das articulações nos seres humanos, através da tração exercida no tendão ou na aponeurose. Os músculos controlam, coordenam e realizam os movimentos articulares. A força produzida pelos músculos pode ser estimada através das alavancas realizadas pelo membro, considerando-se o torque de cada força, quando o músculo se contrai, parte da energia desta contração será dissipada na forma de som. A presente pesquisa tem como objetivo principal desenvolver um sistema para avaliar o sinal acústico muscular e comparar com a força produzida em uma célula de carga pela alavanca do membro superior. Os músculos selecionados para esta pesquisa foram os flexores do cotovelo, pela facilidade de acesso e de posicionamento. Foram coletados os sinais acústicos e do esforço realizado de 16 indivíduos de ambos os sexos, sendo 9 do sexo masculino e 7 do sexo feminino, saudáveis, com idade entre 18 e 35 anos, sem histórico de doenças neurológicas, cardiovasculares, não praticantes de atividade física que produzisse a hipertrofia dos músculos flexores do cotovelo. Foi desenvolvido um sistema para avaliação do sinal acústico muscular utilizando como sensor um estetoscópio adaptado com um microfone, simultaneamente à aquisição do torque produzido pelos flexores do cotovelo e avaliado por uma célula de carga. A presente pesquisa permitiu identificar que as principais freqüências acústicas da contração dos flexores do cotovelo estão na faixa de 10 a 15 Hz quando a contração equivale de 75 a 100% da força máxima para o sexo feminino e de 50 a 100 % da força máxima para o sexo masculino e na faixa de 5 a 10 Hz quando a contração equivale de 25 a 50 % da força máxima para o sexo feminino e 25 % da força máxima para o sexo masculino... / Striated skeletal muscles, through their properties of contractility, extensibility and elasticity, are the main driver of the joints in humans, through the traction exerted on the tendon or aponeurosis, muscle control, coordinate and carry out joint movements. The force produced by muscles can be estimated using from the levers held by the member, considering the torque of each force when the muscle contracts, this contraction of the energy is dissipated in the form of sound. The main objective of this research is to develop a system to evaluate the acustic signal and compare it with the muscular force produced in a load cell by the lever of the upper limb. The muscles selected for this research were elbow flexors, because of the easy access and positioning. Acoustic signals were collected and the effort made to 16 individuals of both sexes. We analyzed 9 male and 7 female, healthy and aged between 18 and 35 years old with no history of neurological and cardiovascular disease and not engaged in physical activity that could develop hypertrophy of the elbow flexor muscles. A system was developed for evaluation of the acoustic signal using muscle as a sensor adapted stethoscope with a microphone, simultaneously with the aquisition of the torque produced by the elbow flexor and evaluated by a load cell. This research has identified that the main acoustic frequencies of contraction of the elbow flexors are in the range of 10 to 15 Hz when the contraction equals 75 to 100% of maximum force for females and 50 to 100% of maximum force to males and in the range 50 to 10 Hz when the contraction equals 25 to 50% of maximum force for females and 25% of maximum force for males, as well as the correlation of the acoustic signals of males female with a coefficient less than 4. It was concluded that the acoustic signal muscle has specific characteristics for different levels of intensity of muscle... (Complete abstract click electronic access below)

Orientador: Araildo Lima da Silva / Banca: Carlos Renato Zacharias / Banca: Clifford Neves Pinto / Resumo: O presente trabalho consiste no estudo do comportamento do fluxo sangüíneo na artéria braquial, através de sinais captados por um microfone acoplado no estetoscópio e utilizado para transformar o sinal acústico (sonoro) em elétrico, e enviá-lo para o computador. O estudo foi realizado oferecendo-se diferentes pressões no esfigmomanômetro, o qual foi adaptado com dois manômetros. Um dos manômetros, graduado em mmHg, não foi modificado, possui o selo do INMETRO e atuou como referência, ao outro foi inserido um extensômetro, que transformou o sinal de pressão em sinal elétrico, utilizando uma ponte amplificada, enviando-o para uma placa de aquisição de dados no computador. Foi traçada uma curva de calibração do sinal elétrico (em mV) com relação ao manômetro graduado em mmHg. Foi proposto um protocolo para aquisição destes sinais a serem analisados, baseado em protocolos de aferição de pressão arterial. O comportamento do fluxo sangüíneo foi comparado às diferentes pressões exercidas pelo esfigmomanômetro. Ao analisar estes dados, foram propostos limites de normalidades da intensidade do sinal do fluxo sangüíneo em diferentes freqüências nas cinco fases da escala de Koroktov. O trabalho mostrou também os limites de normalidade da pressão arterial, utilizando-se o sinal adquirido pela extensometria. Finalmente, foi oferecido mais um auxílio no diagnóstico de patologias do sistema cardiovascular. / Abstract: The present work consists to study the features of blood flow in to the brachial artery through signals detected by a microphone coupled together a stethoscope. This apparatus changes the acoustics in eletric signal and, then, sends to the computer. This study was implemented exhibiting different pressures in the sphygnomanometer, where two manometers, graded in mmHg, were coulpled. One that has the INMETRO certificate of gauging instruments was not modificate and, then, it was used as the standard. In the other, an extensometer was coupled together, which through an amplifier bridge, pressure signals are transformed in electric signals and sent to a data adapter unit connected to the computer. A gauging curve for the eletric signals versus pressure signals was ploted. It was proposed a protocol to adquire these data signals, based on the protocol of brachial pressure measurement. The features of blood flow were compared at different sphygnomanometer pressures. In the analysis process of the data, normality boundaries of intensity were proposed to the blood flow signal at different frequencies in the five phases of the Koroktov scale. The work also showed the normality boundaries of brachial pressure using the data signals adquired by the extensometry process. Finally, it was provided an one more aid in to diagnose pathologies in the cardiovascular system. / Mestre

Traditional fracture testing in the field of athletic training relies heavily on subjective responses of the athlete. Percussion and compression type tests rely on the athlete stating an increase in pain which represents a positive symptom of a possible fracture. The tuning fork and stethoscope method relied purely on a subjective assessment from the examiner. The purpose of the study was to determine if the use of a 128Hz tuning fork and stethoscope were effective evaluation tools in the assessment of possible fractures as compared to the traditional fracture tests that are used in the athletic training field. A vibrating 128 Hz tuning fork was placed on the bone/area where swelling was minor to facilitate good cortical bone contact. Then the conical bell of a stethoscope was placed on the opposite end on the bone or bones. A diminished sound arising from the injured bone as compared to the uninjured represented a positive sign for a possible fracture. Traditional fracture testing was performed and noted. An x-ray, diagnosed by an orthopedic physician, supported the validity of the tuning fork and traditional fracture testing methods. The attempt was to see what testing method, the tuning fork and stethoscope or traditional fracture testing, was a more valid evaluation tool when it comes to fractures. This study was performed at a university's athletic training room and a local orthopedic center. The study consisted of any subject between the ages of 18-85 that presented with a suspected fracture at either testing facilities. The current study examined 37 male and female subjects whose age ranged from 18-85 years old. The long bones that were tested in this research were as follows: the phalanges of the hand and foot, metacarpals, metatarsals, humerus, radius, ulna, fibula (including the lateral malleolus), and tibia (including the medial malleolus). The tuning fork and stethoscope was shown to be an effective and valid tool for evaluating possible fractures by yielding a success rate of 89.2% when compared to an x-ray. The percussion and compression fracture testing methods yielded only a success rate of 67.6% and 64.9% respectively. / Ph. D.

Orientador: Araildo Lima da Silva / Banca: Mauro Gonçalves / Banca: Renato Sousa Almeida / Banca: Mauro Cesar Tavres de Souza / Banca: João Alberto Oliveira / Resumo: Os músculos estriados esqueléticos, através de suas propriedades de contratilidade, extensibilidade e elasticidade, formam o principal motor das articulações nos seres humanos, através da tração exercida no tendão ou na aponeurose. Os músculos controlam, coordenam e realizam os movimentos articulares. A força produzida pelos músculos pode ser estimada através das alavancas realizadas pelo membro, considerando-se o torque de cada força, quando o músculo se contrai, parte da energia desta contração será dissipada na forma de som. A presente pesquisa tem como objetivo principal desenvolver um sistema para avaliar o sinal acústico muscular e comparar com a força produzida em uma célula de carga pela alavanca do membro superior. Os músculos selecionados para esta pesquisa foram os flexores do cotovelo, pela facilidade de acesso e de posicionamento. Foram coletados os sinais acústicos e do esforço realizado de 16 indivíduos de ambos os sexos, sendo 9 do sexo masculino e 7 do sexo feminino, saudáveis, com idade entre 18 e 35 anos, sem histórico de doenças neurológicas, cardiovasculares, não praticantes de atividade física que produzisse a hipertrofia dos músculos flexores do cotovelo. Foi desenvolvido um sistema para avaliação do sinal acústico muscular utilizando como sensor um estetoscópio adaptado com um microfone, simultaneamente à aquisição do torque produzido pelos flexores do cotovelo e avaliado por uma célula de carga. A presente pesquisa permitiu identificar que as principais freqüências acústicas da contração dos flexores do cotovelo estão na faixa de 10 a 15 Hz quando a contração equivale de 75 a 100% da força máxima para o sexo feminino e de 50 a 100 % da força máxima para o sexo masculino e na faixa de 5 a 10 Hz quando a contração equivale de 25 a 50 % da força máxima para o sexo feminino e 25 % da força máxima para o sexo masculino... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Striated skeletal muscles, through their properties of contractility, extensibility and elasticity, are the main driver of the joints in humans, through the traction exerted on the tendon or aponeurosis, muscle control, coordinate and carry out joint movements. The force produced by muscles can be estimated using from the levers held by the member, considering the torque of each force when the muscle contracts, this contraction of the energy is dissipated in the form of sound. The main objective of this research is to develop a system to evaluate the acustic signal and compare it with the muscular force produced in a load cell by the lever of the upper limb. The muscles selected for this research were elbow flexors, because of the easy access and positioning. Acoustic signals were collected and the effort made to 16 individuals of both sexes. We analyzed 9 male and 7 female, healthy and aged between 18 and 35 years old with no history of neurological and cardiovascular disease and not engaged in physical activity that could develop hypertrophy of the elbow flexor muscles. A system was developed for evaluation of the acoustic signal using muscle as a sensor adapted stethoscope with a microphone, simultaneously with the aquisition of the torque produced by the elbow flexor and evaluated by a load cell. This research has identified that the main acoustic frequencies of contraction of the elbow flexors are in the range of 10 to 15 Hz when the contraction equals 75 to 100% of maximum force for females and 50 to 100% of maximum force to males and in the range 50 to 10 Hz when the contraction equals 25 to 50% of maximum force for females and 25% of maximum force for males, as well as the correlation of the acoustic signals of males female with a coefficient less than 4. It was concluded that the acoustic signal muscle has specific characteristics for different levels of intensity of muscle... (Complete abstract click electronic access below) / Doutor

For this project, the design, implementation, characterization, calibration and possible applications of a multiple transducer stethoscope apparatus were investigated. The multi-transducer sensor array design consists of five standard stethoscope diaphragms mounted to a rigid frame for a-priori knowledge of their relative spatial locations in the x-y plane, with compliant z-direction positioning to ensure good contact and pressure against the subject’s skin for reliable acoustic coupling. When this apparatus is properly placed on the body, it can digitally capture the same important body sounds investigated with standard acoustic stethoscopes; especially heart sounds. Acoustic signal inputs from each diaphragm are converted to electrical signals through microphone pickups installed in the stethoscope connective tubing; and are subsequently sampled and digitized for analysis. With this system, we are able to simultaneously interrogate internal body sounds at a sampling rate of 2 KHz, as most heart sounds of interest occur below 200 Hz. This system was characterized and calibrated by chirp and impulse signal tests. After calibrating the system, a variety of methods for combining the individual sensor channel data to improve the detectability of different signals of interest were explored using variable-delay beam forming. S1 and S2 heart sound recognition with optimized beam forming delays and inter-symbol noise elimination were investigated for improved discernment of the S1 or S2 heart sounds by a user. Also, stereophonic presentation of heart sounds was also produced to allow future investigation of its potential clinical diagnostic efficacy.

A quarter of the world's population experience wheezing. These sounds have been used for diagnosis since the time of the Ebers Papyrus (ca. 1500 BC), but the underlying physical mechanism responsible for the sounds is still poorly understood. The main purpose of this thesis is to change this, developing a theory for the onset of wheezing using both experimental and analytical approaches, with implications for both scientific understanding and clinical diagnosis. Wheezing is caused by a fluid structure interaction between the airways and the air flowing through them. We have developed the first systematic set of experiments of direct relevance to this physical phenomena. We have also developed new tools in shell theory using geometric algebra to improve our physical understanding of the self-excited oscillations observed when air flows through flexible tubes. In shell theory, the use of rotors from geometric algebra has enabled us to develop improved physical understanding of how changes of curvature, which are of direct importance to constitutive laws, come about. This has enabled a scaling analysis to be applied to the self-excited oscillations of flexible tubes, showing for the first time that bending energy is dominated by strain energy. We made novel use of multiple camera reconstruction to validate this scaling analysis by directly measuring the bending and strain energies during oscillations. The dominance of strain energy allows a simplification of the governing shell equations. We have developed the first theory for the onset of self-excited oscillations of flexible tubes based on a flutter instability. This has been validated with our experimental work, and provides a predictive tool that can be used to understand wheezing in the airways of the lung. Our theory for the onset of wheezing relates the frequency of oscillation to the airway geometry and material properties. This will allow diagnoses based on wheezing sounds to become more specific, which will allow the stethoscope, which has changed little in the last 200 years, to be brought into the 21st century.

Stethoscopes are the most commonly used medical devices for diagnosing heart conditions because they are inexpensive, noninvasive, and light enough to be carried around by a clinician. Auscultation with a stethoscope requires considerable skill and experience, but the introduction of digital stethoscopes allows for the automation of this task. Auscultation waveform segmentation, which is the process of determining the boundaries of heart sound and murmur segments, is the primary challenge in automating the diagnosis of various heart conditions. The purpose of this thesis is to improve the accuracy and efficiency of established techniques for detecting, segmenting, and classifying heart sounds and murmurs in digitized phonocardiogram audio files. Two separate segmentation techniques based on the discrete wavelet transform (DWT) and the simplicity transform are integrated into a MATLAB software system that is capable of automatically detecting and classifying sound segments. The performance of the two segmentation methods for recognizing normal heart sounds and several different heart murmurs is compared by quantifying the results with clinical and technical metrics. The two clinical metrics are the false negative detection rate (FNDR) and the false positive detection rate (FPDR), which count heart cycles rather than sound segments. The wavelet and simplicity methods have a 4% and 9% respective FNDR, so it is unlikely that either method would not detect a heart condition. However, the 22% and 0% respective FPDR signifies that the wavelet method is likely to detect false heart conditions, while the simplicity method is not. The two technical metrics are the true murmur detection rate (TMDR) and the false murmur detection rate (FMDR), which count sound segments rather than heart cycles. Both methods are equally likely to detect true murmurs given their 83% TMDR. However, the 13% and 0% respective FMDR implies that the wavelet method is susceptible to detecting false murmurs, while the simplicity method is not. Simplicity-based segmentation, therefore, demonstrates superior performance to wavelet-based segmentation, as both are equally likely to detect true murmurs, but only the simplicity method has no chance of detecting false murmurs.

An early detection of heart disease can save lives, caution individuals and also help to determine the type of treatment to be given to the patients. The first test of diagnosing a heart disease is through auscultation - listening to the heart sounds. The interpretation of heart sounds is subjective and requires a professional skill to identify the abnormalities in these sounds. A medical practitioner uses a stethoscope to perform an initial screening by listening for irregular sounds from the patient's chest. Later, echocardiography and electrocardiography tests are taken for further diagnosis. However, these tests are expensive and require specialized technicians to operate. A simple and economical way is vital for monitoring in homecare or rural hospitals and urban clinics. This dissertation is focused on developing a patient-centered device for initial screening of the heart sounds that is both low cost and can be used by the users on themselves, and later share the readings with the healthcare providers. An innovative mobile health service platform is created for analyzing and classifying heart sounds. Certain properties of heart sounds have to be evaluated to identify the irregularities such as the number of heart beats and gallops, intensity, frequency, and duration. Since heart sounds are generated in low frequencies, human ears tend to miss certain sounds as the high frequency sounds mask the lower ones. Therefore, this dissertation provides a solution to process the heart sounds using several signal processing techniques, identifies the features in the heart sounds and finally classifies them. This dissertation enables remote patient monitoring through the integration of advanced wireless communications and a customized low-cost stethoscope. It also permits remote management of patients' cardiac status while maximizing patient mobility. The smartphone application facilities recording, processing, visualizing, listening, and classifying heart sounds. The application also generates an electronic medical record, which is encrypted using the efficient elliptic curve cryptography and sent to the cloud, facilitating access to physicians for further analysis. Thus, this dissertation results in a patient-centered device that is essential for initial screening of the heart sounds, and could be shared for further diagnosis with the medical care practitioners.