Zugl.: Habil'schrift Bern.

Thesis (M. Tech. (Clinical technology )) - Central University of technology, Free State, 2013 / The incidence of epilepsy is high in sub-Saharan Africa and resource poor countries (RPCs). There are few neurologists and paediatric neurologists to manage people with epilepsy (PWE). Health care is often limited, particularly technological services, including electroencephalogram (EEG), video EEG monitoring, and Neuroradiology services. All these are important in the management of PWE. Since 2008, informal electrophysiology training has been provided at the Red Cross War Memorial Hospital, in the Department of Paediatric Neurology. The Principal Investigator (PI) elected to develop a formal teaching course on EEG interpretation at the Red Cross War Memorial Hospital. A study was designed to evaluate the practical use of a handbook entitled “Handbook of Paediatric Electroencephalography: A guide to basic paediatric electroencephalogram interpretation.” This has been developed to fulfill the need for basic understanding and interpretation of EEG amongst clinicians caring for children in sub-Saharan Africa who may not have access to, or be able to afford, training at a recognized facility or on-line. In 2008, the department of Paediatric Neurology at the Red Cross War Memorial Hospital had their first African fellow from Kenya. By 2011, seven participants had undergone EEG training. A quantitative research approach and design was used in order to evaluate the handbook in terms of the accessibility of the contents and its practical use. Quantification included the recruitment of participants who constituted the population sample, a pilot study, and the collection of data from comparative assessments of participants’ use of the handbook, and from questionnaires completed by participants. This provided the researcher with the opportunity to improve and validate her knowledge of training in EEG interpretation. The researcher was able to quantify and compare the scores of participants using the handbook, as well as to compare their evaluative responses to its content and practical use. Eleven of thirteen participants completed the study. The pre-training results showed a median percentage of 50 which increased to 70 percent post-test. A comparison of the scores of trained versus not-trained revealed that those participants who had undergone one-on-one training on site at the unit fared much better both in their interpretations, conclusions, and reporting of EEG findings. The responses from the evaluative and comparative survey between the two groups showed no significant difference across all questions, the majority of the questions on the relative usefulness of the handbook being rated ‘agree’ and ‘strongly agree’, thus supporting the finding that all participants found the handbook useful whether they had received one-on-one training or not. The post-training results in EEG interpretation showed a stronger trend towards statistical significance (p<0.06) with trained participants and with the not-trained. These findings lend support to the success and usefulness of the handbook as a basic guide to paediatric EEG interpretation. The handbook was not aimed at making the electroencephalography reader an expert at a specialist level, but rather to maximize the reliability of the reading of EEG when screening electroencephalograms for important key diagnostic markers which would alter the child’s management. This is the first published handbook on paediatric EEG in South Africa. The results of this study strongly suggest that the handbook is useful as a learning and reference tool in interpretation of paediatric EEG, both for individuals with access to one-on-one training as well as those without. It is intended that the handbook, in conjunction with one-on-one training, will form part of a post-graduate diploma course offered by the University of Cape Town on “basic electrophysiology and the management of children with epilepsy” for training neurologists and child neurologists, paediatricians and health care workers in sub-Saharan Africa.

L’accouchement prématuré est un problème de santé publique dans le monde et notamment dans les pays économiquement développés avec un taux variant entre 7 et 12 % des naissances. Le diagnostic du risque d’accouchement prématuré est difficile à faire et les outils à notre disposition ont peu évolué ces dernières années. La contraction utérine est la conséquence directe de l’activité électrique au niveau du myomètre. Le type de contraction est lié à l’importance de l’excitabilité cellulaire et de sa diffusion à l’ensemble du myomètre. Le recueil et l’analyse de cette activité électrique par des électrodes de surface est aujourd’hui le seul moyen non invasif d’étudier, pendant la grossesse, les mécanismes qui sont à l’origine de la contraction. L’enregistrement de l’électromyogramme utérin ou électrohystérogramme (EHG) est donc prometteur pour réaliser un diagnostic et une surveillance des femmes à risque d’accouchement prématuré. Dans ce travail de thèse 3 études cliniques ont été réalisées. Dans la première, j’ai étudié différentes électrodes de surface permettant d’enregistrer les signaux électriques. Je propose à la fin de cette première partie un système d’électrodes pour permettre à la fois un enregistrement de qualité et une pose aisée compatible avec une application clinique. Dans la deuxième étude j’ai étudié la détection automatique des contractions par l’EHG avec des résultats encourageants pour l’application clinique et notamment en ambulatoire. Enfin dans la troisième étude j’ai étudié la prédiction du risque d’accouchement prématuré par l’analyse de paramètres électriques issus de l’EHG. Les résultats obtenus permettent d’améliorer la prédiction du risque d’accouchement prématuré par rapport aux outils utilisés en routine. / Premature birth is a public health problem in the world, particularly in economically developed countries with a rate varying between 7% and 12% of births. The diagnosis of the risk of premature labor is difficult to make and the tools at our disposal have changed little in recent years. Uterine contraction is a direct consequence of electrical activity at the level of the myometrium. The type of contraction is related to the importance of cell excitability and its diffusion to the entire myometrium. The analysis of this electrical activity by surface electrodes is currently the only non-invasive way to study the mechanisms that are at the origin of the contraction. The recording of the uterine electromyogram or electrohysterogram (EHG) is therefore promising for the diagnosis and surveillance of women at risk of preterm birth. In this thesis work 3 clinical studies have been carried out. In the first clinical study, different surface electrodes to record electrical signals were tested. I propose at the end of this first part a system of electrodes to allow at the same time a recording of quality and an easy pose compatible with a clinical application. In the second study , the automatic detection of contractions by the El-IG was studied with encouraging results for the clinical application and especially in ambulatory. Finally, in the third clinical experiment, I studied the prediction of the risk of premature delivery by the analysis of electrical parameters extracted from the EHG. The results obtained make it possible to improve the prediction of the risk of premature delivery compared to the tools used routinely.

Orientadores: Cássio Luis Zannettini Riccetto, Simone Botelho Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-20T03:58:07Z (GMT). No. of bitstreams: 1 Lanza_AnaHelenaBarbosa_M.pdf: 1640627 bytes, checksum: c135a5857fcde47208c0a3c7f837045b (MD5) Previous issue date: 2011 / Resumo: Objetivo. Avaliar o efeito de um programa supervisionado de cinesioterapia sobre a contratilidade do assoalho pélvico, e sua eventual correlação com a função orgásmica feminina. Sujeito e Métodos. Para este estudo clínico, prospectivo, randomizado, controlado e cego, foram inclusas 20 mulheres, com média de idade de 26,6 ± 6,1 anos, com queixa de falta de orgasmo durante a atividade sexual, as quais foram divididas aleatoriamente em dois grupos. Grupo 1 (G1): 10 mulheres; avaliadas quanto à função orgásmica e quanto à contratilidade muscular do assoalho pélvico; realizaram um protocolo de exercícios cinesioterapêuticos (12 sessões individuais, com duração de 30 minutos, duas vezes por semana), focado no fortalecimento muscular pélvico; e reavaliada quanto à função orgásmica e quanto à contratilidade muscular; Grupo 2 (G2): 10 mulheres; avaliadas quanto à função orgásmica e quanto à contratilidade muscular do assoalho pélvico; não realizaram o protocolo de exercícios cinesioterapêuticos; foram reavaliadas quanto à função orgásmica e quanto à contratilidade muscular simultaneamente às mulheres do G1, sendo denominado G2-Controle. Após uma semana, esse grupo realizou o mesmo protocolo de exercícios cinesioterapêuticos, foi reavaliado quanto à função orgásmica e quanto à contratilidade muscular, sendo denominado G2-Tratado. A função orgásmica foi avaliada por meio do domínio orgasmo do questionário validado para língua portuguesa Female Sexual Function Index (FSFI), e por meio do cálculo do Coeficiente de Capacidade Orgásmica (CCO). As avaliações da contratilidade muscular do assoalho pélvico foram realizadas por segundo pesquisador, o qual não tinha conhecimento do programa de tratamento, através de palpação digital (PD) e de eletromiografia de superficie (EMGs - com sensor intravaginal), enquanto que, o programa de exercícios cinesioterapêuticos foi elaborado e supervisionado por pesquisador, o qual não participou das avaliações da contratilidade muscular do assoalho pélvico. O questionário International Consultation on Incontinence Questionnaire Short-Form, validado para a língua portuguesa, foi aplicado na avaliação inicial, no intuito de verificar a coexistência da incontinência urinária. Para análise estatística foram utilizados o Teste t de Student, o Teste de Correlação de Pearson, e o Teste Regressão Linear Simples, com nível de significância de 5%. Resultados. Em contraste com o grupo controle (G2-Controle), os grupos que realizaram o programa de exercícios cinesioterapêuticos proposto (G1 e G2-Tratado) apresentaram aumento significativo na contratilidade do assoalho pélvico, tanto a avaliada pela PD (p<0,001), quanto a mensurada pela EMGs (p<0,001), e este aumento de contratilidade se correlacionou de forma significativa com a melhora no escore do domínio orgasmo do FSFI (p<0,001), e no escore do Coeficiente de Capacidade Orgásmica (p=0,001). Conclusão. O programa de exercícios cinesioterapêuticos proposto promoveu aumento na contratilidade do assoalho pélvico, com concomitante melhora da função orgásmica, indicando que essa abordagem terapêutica possa ser adjuvante no tratamento da disfunção orgásmica feminina / Abstract: Objective. Evaluate the effect of a protocol supervised of the kinesiotherapy on the contractility of the pelvic floor, and its possible correlation with female orgasmic function. Subjects and methods. For this clinical, prospective, randomized, controlled, blind study, were included 20 women, mean age 26.6 ± 6.1 years, complaining of lack of orgasm during sexual activity, which were randomly divided into two groups. Group 1 (G1): 10 women, evaluated for orgasmic function and on the contractility of the pelvic floor, made a kinesiotherapy protocol (12 sessions, lasting 30 minutes, twice a week), focused on muscle strengthening, and reassessed as the orgasmic function and the contractility of the pelvic floor; Group 2 (G2): 10 women, evaluated for orgasmic function and on the contractility of the pelvic floor, did not realize the kinesiotherapy protocol, were reassessed on the orgasmic function and on the contractility of the pelvic floor while the women in the G1, and called G2- Control. After one week, this group received the same kinesiotherapy protocol, was reassessed as the orgasmic function and on the contractility of the pelvic floor, and called G2- Treaty. Orgasmic function was assessed using the orgasm domain of the validated questionnaire to portuguese Female Sexual Function Index (FSFI), and by calculating the Coefficient of Orgasmic Capacity (COC). The assessments of the pelvic floor muscle contractility were performed by the second researcher, which was not aware of the treatment program, by digital palpation (DP) and surface electromyography (sEMG - with intravaginal sensor), while kinesiotherapy program was drafted and supervised by a researcher no involved in the assessments of contractility of the pelvic floor. The International Consultation on Incontinence Questionnaire, validated for the portuguese language was used in the initial assessment, in order to verify the coexistence of urinary incontinence. Statistical analysis was performed using the Student t Test, the Pearson Correlation Test, and the Simple Linear Regression Test, with a significance level of 5%. Results. In contrast to the control group xvi (G2-control), groups that performed kinesiotherapy (G1 and G2-Treaty) showed a significant increase in contractility of the pelvic floor, assessed by PD (p <0,001), and measured by EMG (p <0.001), and this increase in contractility was positively correlated with the improvement in the orgasm domain score of the FSFI (p <0,001), and the score of the Coefficient Orgasmic Capacity (p = 0,001). Conclusion. The kinesiotherapy exercises program promoted increase in contractility of the pelvic floor, with concomitant improvement in orgasmic function, indicating that this therapeutic approach could be an adjunct in the treatment of female orgasmic dysfunction / Mestrado / Fisiopatologia Cirúrgica / Mestre em Ciências da Cirurgia

For most of the naturally occurring signals, especially biomedical signals, the underlying physical process generating the signal is often not fully known, making it difficult to obtain a parametric model. Therefore, signal processing techniques are used to analyze the signal for non-parametrically characterizing the underlying system from which the signals are produced. Most of the real life systems are nonlinear and time varying, which poses a challenge while characterizing them. Additionally, multiple sensors are used to extract signals from such systems, resulting in multichannel signals which are inherently coupled. In this thesis, we counter this challenge by using Recurrence Plot based techniques for characterizing biomedical systems such as heart or brain, using signals such as heart rate variability (HRV), electroencephalogram(EEG) or functional magnetic resonance imaging (fMRI), respectively, extracted from them. In time series analysis, it is well known that a system can be represented by a trajectory in an N-dimensional state space, which completely represents an instance of the system behavior. Such a system characterization has been done using dynamical invariants such as correlation dimension, Lyapunov exponent etc. Takens has shown that when the state variables of the underlying system are not known, one can obtain a trajectory in ‘phase space’ using only the signals obtained from such a system. The phase space trajectory is topologically equivalent to the state space trajectory. This enables us to characterize the system behavior from only the signals sensed from them. However, estimation of correlation dimension, Lyapunov exponent, etc, are vulnerable to non-stationarities in the signal and require large number of sample points for accurate computation, both of which are important in the case of biomedical signals. Alternatively, a technique called Recurrence Plots (RP) has been proposed, which addresses these concerns, apart from providing additional insights. Measures to characterize RPs of single and two channel data are called Recurrence Quantification Analysis (RQA) and cross RQA (CRQA), respectively. These methods have been applied with a good measure of success in diverse areas. However, they have not been studied extensively in the context of experimental biomedical signals, especially multichannel data. In this thesis, the RP technique and its associated measures are briefly reviewed. Using the computational tools developed for this thesis, RP technique has been applied on select single channel, multichannel and multimodal (i.e. multiple channels derived from different modalities) biomedical signals. Connectivity analysis is demonstrated as post-processing of RP analysis on multichannel signals such as EEG and fMRI. Finally, a novel metric, based on the modification of a CRQA measure is proposed, which shows improved results. For the case of single channel signal, we have considered a large database of HRV signals of 112 subjects recorded for both normal and abnormal (anxiety disorder and depression disorder) subjects, in both supine and standing positions. Existing RQA measures, Recurrence Rate and Determinism, were used to distinguish between normal and abnormal subjects with an accuracy of 58.93%. A new measure, MLV has been introduced, using which a classification accuracy of 98.2% is obtained. Correlation between probabilities of recurrence (CPR) is a CRQA measure used to characterize phase synchronization between two signals. In this work, we demonstrate its utility with application to multimodal and multichannel biomedical signals. First, for the multimodal case, we have computed running CPR (rCPR), a modification proposed by us, which allows dynamic estimation of CPR as a function of time, on multimodal cardiac signals (electrocardiogram and arterial blood pressure) and demonstrated that the method can clearly detect abnormalities (premature ventricular contractions); this has potential applications in cardiac care such as assisted automated diagnosis. Second, for the multichannel case, we have used 16 channel EEG signals recorded under various physiological states such as (i) global epileptic seizure and pre-seizure and (ii) focal epilepsy. CPR was computed pair-wise between the channels and a CPR matrix of all pairs was formed. Contour plot of the CPR matrix was obtained to illustrate synchronization. Statistical analysis of CPR matrix for 16 subjects of global epilepsy showed clear differences between pre-seizure and seizure conditions, and a linear discriminant classifier was used in distinguishing between the two conditions with 100% accuracy. Connectivity analysis of multichannel EEG signals was performed by post-processing of the CPR matrix to understand global network-level characterization of the brain. Brain connectivity using thresholded CPR matrix of multichannel EEG signals showed clear differences in the number and pattern of connections in brain connectivity graph between epileptic seizure and pre-seizure. Corresponding brain headmaps provide meaningful insights about synchronization in the brain in those states. K-means clustering of connectivity parameters of CPR and linear correlation obtained from global epileptic seizure and pre-seizure showed significantly larger cluster centroid distances for CPR as opposed to linear correlation, thereby demonstrating the efficacy of CPR. The headmap in the case of focal epilepsy clearly enables us to identify the focus of the epilepsy which provides certain diagnostic value. Connectivity analysis on multichannel fMRI signals was performed using CPR matrix and graph theoretic analysis. Adjacency matrix was obtained from CPR matrices after thresholding it using statistical significance tests. Graph theoretic analysis based on communicability was performed to obtain community structures for awake resting and anesthetic sedation states. Concurrent behavioral data showed memory impairment due to anesthesia. Given the fact that previous studies have implicated the hippocampus in memory function, the CPR results showing the hippocampus within the community in awake state and out of it in anesthesia state, demonstrated the biological plausibility of the CPR results. On the other hand, results from linear correlation were less biologically plausible. In biological systems, highly synchronized and desynchronized systems are of interest rather than moderately synchronized ones. However, CPR is approximately a monotonic function of synchronization and hence can assume values which indicate moderate synchronization. In order to emphasize high synchronization/ desynchronization and de-emphasize moderate synchronization, a new method of Correlation Synchronization Convergence Time (CSCT) is proposed. It is obtained using an iterative procedure involving the evaluation of CPR for successive autocorrelations until CPR converges to a chosen threshold. CSCT was evaluated for 16 channel EEG data and corresponding contour plots and histograms were obtained, which shows better discrimination between synchronized and asynchronized states compared to the conventional CPR. This thesis has demonstrated the efficacy of RP technique and associated measures in characterizing various classes of biomedical signals. The results obtained are corroborated by well known physiological facts, and they provide physiologically meaningful insights into the functioning of the underlying biological systems, with potential diagnostic value in healthcare.