Ventricular premature beats are ectopic changes in the ECG signal. Detection of ventricular extrasystoles on 12leads ECG was created in MATLAB. At first my work involves whether the ventricular premature beats comes from the right or the left ventricle. Another algorithm evaluates the incidence outflow tract of the chamber. If the previous algorithm shows signs of indecision, another algorithm is used for detection of ventricular extrasystoles at another location in the left ventricle. The last step is to narrow the area of detection which makes it easier to find the place of origin.

This study aimed to explore the application of artificial intelligence (AI) and machine learning (ML) techniques in implementing a QRS detector forambulatory electrocardiography (ECG) monitoring devices. Three ML models, namely long short-term memory (LSTM), convolutional neural network (CNN), and multilayer perceptron (MLP), were compared and evaluated using the MIT-BIH arrhythmia database (MITDB) and the MIT-BIH noise stress test database (NSTDB). The MLP model consistently outperformed the other models, achieving high accuracy in R-peak detection. However, when tested on noisy data, all models faced challenges in accurately predicting R-peaks, indicating the need for further improvement. To address this, the study emphasized the importance of iteratively refining the input data configurations for achieving accurate R-peak detection. By incorporating both the MITDB and NSTDB during training, the models demonstrated improved generalization to noisy signals. This iterative refinement process allowed for the identification of the best models and configurations, consistently surpassing existing ML-based implementations and outperforming the current ECG analysis system. The MLP model, without shifting segments and utilizing both datasets, achieved an outstanding accuracy of 99.73 % in R-peak detection. This accuracy exceeded values reported in the literature, demonstrating the superior performance of this approach. Furthermore, the shifted MLP model, which considered temporal dependencies by incorporating shifted segments, showed promising results with an accuracy of 99.75 %. It exhibited enhanced accuracy, precision, and F1-score compared to the other models, highlighting the effectiveness of incorporating shifted segments. For future research, it is important to address challenges such as overfitting and validate the models on independent datasets. Additionally, continuous refinement and optimization of the input data configurations will contribute to further advancements in ECG signal analysis and improve the accuracy of R-peak detection. This study underscores the potential of ML techniques in enhancing ECG analysis, ultimately leading to improved cardiac diagnostics and better patient care. / Syftet med denna studie var att utforska användningen av AI- och ML-tekniker för att implementera en QRS-detektor i EKG-övervakningsenheter. Tre olika ML-modeller, LSTM, CNN och MLP jämfördes och utvärderades med hjälp av MITDB och NSTDB. Resultaten visade att MLP-modellen konsekvent presterade bättre än de andra modellerna och uppnådde hög noggrannhet vid detektion av R-toppar i EKG-signalen. Trots detta stötte alla modeller på utmaningar när de testades på brusig realtidsdata, vilket indikerade behovet av ytterligare förbättringar. För att hantera dessa utmaningar betonade studien vikten av att iterativt förbättra konfigurationen av indata för att uppnå noggrann detektering av R toppar. Genom att inkludera både MITDB och NSTDB under träningen visade modellerna förbättrad förmåga att generalisera till brusiga signaler. Denna iterativa process möjliggjorde identifiering av de bästa modellerna och konfigurationerna, vilka konsekvent överträffade befintliga ML-baserade implementeringar och presterade bättre än den nuvarande EKG-analysystemet. MLP-modellen, utan användning av skiftade segment och med båda databaserna, uppnådde en imponerande noggrannhet på 99,73 % vid detektion av R-toppar. Denna noggrannhet överträffade tidigare studier och visade på den överlägsna prestandan hos denna metod. Dessutom visade den skiftade MLP-modellen, som inkluderade skiftade segment för att beakta tidsberoenden, lovande resultat med en noggrannhet på 99,75 %. Modellen uppvisade förbättrad noggrannhet, precision och F1-score jämfört med de andra modellerna, vilket betonar vikten av att inkludera skiftade segment. För framtida studier är det viktigt att hantera utmaningar som överanpassning och att validera modellerna med oberoende datamängder. Dessutom kommer en kontinuerlig förfining och optimering av konfigurationen av indata att bidra till ytterligare framsteg inom EKG-signalanalys och förbättrad noggrannhet vid detektion av R-toppar. Denna studie understryker potentialen hos ML-modeller för att förbättra EKG-analysen och därigenom bidra till förbättrad diagnostik av hjärtsjukdomar och högre kvalitet inom patientvården.

La thérapie de resynchronisation cardiaque (CRT) est un traitement qui diminue la mortalité et améliore la qualité de vie des patients atteints d’insuffisance cardiaque et présentant un dyssynchronisme de la contraction ventriculaire gauche. Malgré le succès de cette thérapie, plus de 30% des patients ne présentent pas l’amélioration désirée. Plusieurs études portant sur le synchronisme électrique ou mécanique de la contraction ont été effectuées mais peu d’entres elles se sont attardées sur le couplage électromécanique à l'échelle macroscopique. Ce projet a comme objectif d’observer le comportement électromécanique des ventricules canins en présence d’un resynchronisateur cardiaque. Un logiciel a été développé pour permettre l’analyse des informations provenant de la cartographie endocardique sans contact et de la ventriculographie isotopique tomographique chez 12 sujets canins insuffisants. Pour observer la réponse mécanique suite à l’activation électrique, nous avons premièrement recalé les surfaces issues des 2 modalités. Ensuite, nous avons défini les limites du cycle cardiaque, analysé les signaux électriques et les courbes de déplacement de la paroi endocardique. Le début de la contraction est défini par un déplacement radial de 10% vers le centre du ventricule. Les résultats démontrent que la durée d’activation du ventricule gauche et la largeur du QRS augmentent en présence d’une stimulation externe et que les délais électromécaniques sont indépendants dans les modes de stimulation étudiés (sinusal, LVbasal, RVapex ou BIV) avec une moyenne de 84,56±7,19 ms. Finalement, nous avons noté que la stimulation basolatérale procure une fonction cardiaque optimale malgré une durée prolongée du QRS. / Cardiac Resynchronization Therapy (CRT) is known to decrease mortality rate and improve the quality of life for patients suffering from heart failure with left ventricular contraction dyssynchrony. However, it has been shown that 30% of patients do not respond to this therapy. Many studies have investigated the electrical or mechanical synchronism of contraction but few have studied the activation contraction coupling on a macroscopic level. The objective of this study is to observe the left ventricle’s electromechanical behaviour under biventricular stimulation. A software has been developed to analyse the data coming from non-contact mapping and blood pool SPECT for 12 dogs with heart failure. In order to observe the mechanical response following an electrical activation, we have registered 3D surfaces generated by the 2 modalities. Afterward, we defined the cardiac cycle limits, and we analyzed electrical signals as well as endocardial wall displacement curves where the onset of contraction was defined as a 10% inward radial displacement. Results show that both duration of left ventricular activation and QRS increase with pacing and that electromechanical delays are independent of stimulation mode (mean value 84,56 ± 7,19 ms). Finally, we observed that basolateral stimulation shows the best improvement for left ventricular function while presenting a long QRS duration.

Made available in DSpace on 2016-06-02T19:44:15Z (GMT). No. of bitstreams: 1 5500.pdf: 1504247 bytes, checksum: f15a096083eaa9e212e58e30b50376b1 (MD5) Previous issue date: 2013-07-31 / Universidade Federal de Sao Carlos / Family members of people with disabilities may be exposed to various stressors, among them the disability itself, becoming potential targets of stress. In this context, several models have been designed for the study of stress, among which highlights the Cognitive Assessment and the ABC-X, which comprise the coping strategies as a way to mediate the perception of stressors. Researches conducted with several family members have pointed out that the constant stress can lead to more roughness family relationships, and fewer opportunities for stimulation of child development, which contribute to enhance family relationships with any child, including those with disabilities. For the evaluation of the parental stress variable, studies show the use of different instruments, including the Questionnaire on Resources and Stress - QRS-F which stand out for being directed especially to families of children with disabilities and chronic illnesses. Given the above, this study proposed two objectives: 1) the cross-cultural adaptation of the QRS-F, since the translations available in Brazil do not have this treatment, or definitely modified the structure of the questionnaire, 2) a study of the evidence of psychometric validity of the instrument . The first study involved five independent translators, five professionals on the thematic area of the instrument and seven relatives of people with autism. The questionnaire underwent procedures of translation and retranslation, as well translations adjustments, resulting in altered or partially altered. The evaluation of the expert committee regarding the relevance of the questions in the conceptual levels, language and experimental indicated substantial kappa at all levels of assessment, indicating that the translation was adequate for the pilot application. The second study involved 57 mothers, fathers, grandparents and sister of children with and without various disabilities. Their analyzes showed significant correlations with the measure of stress obtained by Symptom Inventory Lipp Stress and the instrument that assessed coping resources, the Coping Strategies Inventory, indicating associations with the dimensions of the QRS-F Parental Problems, Pessimism and Physical Incapacity . The reliability coefficient obtained by the proof of Kuder-Richardson pointed a ratio considered adequate (KR-20 = .64). The test criterion validity indicated higher scores related to the dimension of the QRS-F called Pessimism, when compared groups of respondents relatives of people with and without various disabilities. It was considered that this version of the QRS-F, now called Questionnaire of Resources and Stressors, possesses the attributes necessary to be considered a valid tool in research in the area of parental stress in Brazil. It is suggested to do a further study, covering a broader sample of respondents, which allow the realization of more sophisticated analyzes, but indispensable for the consolidation of this instrument. / Membros de famílias de pessoas com deficiências podem estar expostos a vários estressores, dentre os quais as necessidades desencadeadas pelas próprias condições, tornando-se alvos potenciais de situações de estresse. Neste contexto, diversos modelos foram concebidos para o estudo do estresse, dentre os quais se destaca a Avaliação Cognitiva e o ABC-X, os quais compreendem as estratégias de enfrentamento como uma maneira de se mediar a percepção dos estressores. Pesquisas realizadas com diversos membros da família tem apontado que o estresse constante pode conduzir a relações familiares de mais aspereza, bem como menores oportunidades de estimulação do desenvolvimento infantil, às quais contribuem para potencializar a relações familiares com qualquer criança, inclusive aquelas com deficiências. Para a avaliação da variável estresse parental, as pesquisas apontam o emprego de variados instrumentos, dos quais o Questionnaire on Resources and Stress QRS-F se destaca por direcionar-se especialmente às famílias de crianças com deficiências e doenças crônicas. Diante do exposto, este estudo propôs dois objetivos: 1) a adaptação transcultural do QRS-F, visto que as traduções disponíveis no Brasil não possuem esse tratamento, ou modificaram definitivamente a estrutura do questionário; 2) um estudo das evidências de validade psicométricas do instrumento. Participaram do primeiro estudo cinco tradutores independentes, cinco profissionais da área temática do instrumento e sete familiares de pessoas com autismo. O questionário passou por procedimentos de tradução e retradução, bem como ajuizamento das traduções, resultando em traduções alteradas ou parcialmente alteradas. A avaliação do comitê de especialistas quanto à pertinência das questões nos níveis conceituais, idiomáticos e experimentais indicou kappa substancial em todos os níveis de avaliação, indicando que a tradução estava adequada para a aplicação piloto. No segundo estudo, participaram 57 mães, pais, avós e irmã de crianças com e sem variadas deficiências. Suas análises indicaram correlações significativas com a medida de estresse obtidas pelo Inventário de Sintomas de Stress de Lipp e o instrumento que avaliou recursos de coping, o Inventário de Estratégias de Enfrentamento, indicando associações com as dimensões do QRS-F Problemas Parentais, Pessimismo e Incapacidade Física. O coeficiente de fidedignidade obtido pela prova de Kuder-Richardson apontou um índice considerado adequado (KR-20 = 0,64). O teste de validade de critério indicou maiores pontuações especialmente quanto à dimensão do QRS-F denominada Pessimismo, quando comparados os grupos de respondentes familiares de pessoas com e sem variadas deficiências. Considerou-se que esta versão do QRS-F, agora denominada Questionário de Recursos e Estressores, possui os atributos necessários para ser considerado um instrumento válido em pesquisa na área de estresse parental no Brasil. Sugere-se a realização de estudos posteriores que contemplem uma amostra mais ampla de respondentes, os quais possibilitem a realização de análises mais sofisticadas, porém indispensáveis para a consolidação deste instrumento.

Work is aimed at the time-frequency decomposition of a signal application for monitoring the EKG trend progression. Goal is to create algorithm which would watch changes in the ST segment in EKG recording and its realization in the Matlab program. Analyzed is substance of the origin of EKG and its measuring. For trend calculations after reading the signal is necessary to preprocess the signal, it consists of filtration and detection of necessary points of EKG signal. For taking apart, also filtration and measuring the signal is used wavelet transformation. Source of the data is biomedicine database Physionet. As an outcome of the algorithm are drawn ST segment trends for three recordings from three different patients and its comparison with reference method of ST qualification. For qualification of the heart stability, as a system, where designed methods watching differences in position of the maximal value in two-zone spectrum and the Poincare mapping method. Realized method is attached to this thesis.

La thérapie de resynchronisation cardiaque (CRT) est un traitement qui diminue la mortalité et améliore la qualité de vie des patients atteints d’insuffisance cardiaque et présentant un dyssynchronisme de la contraction ventriculaire gauche. Malgré le succès de cette thérapie, plus de 30% des patients ne présentent pas l’amélioration désirée. Plusieurs études portant sur le synchronisme électrique ou mécanique de la contraction ont été effectuées mais peu d’entres elles se sont attardées sur le couplage électromécanique à l'échelle macroscopique. Ce projet a comme objectif d’observer le comportement électromécanique des ventricules canins en présence d’un resynchronisateur cardiaque. Un logiciel a été développé pour permettre l’analyse des informations provenant de la cartographie endocardique sans contact et de la ventriculographie isotopique tomographique chez 12 sujets canins insuffisants. Pour observer la réponse mécanique suite à l’activation électrique, nous avons premièrement recalé les surfaces issues des 2 modalités. Ensuite, nous avons défini les limites du cycle cardiaque, analysé les signaux électriques et les courbes de déplacement de la paroi endocardique. Le début de la contraction est défini par un déplacement radial de 10% vers le centre du ventricule. Les résultats démontrent que la durée d’activation du ventricule gauche et la largeur du QRS augmentent en présence d’une stimulation externe et que les délais électromécaniques sont indépendants dans les modes de stimulation étudiés (sinusal, LVbasal, RVapex ou BIV) avec une moyenne de 84,56±7,19 ms. Finalement, nous avons noté que la stimulation basolatérale procure une fonction cardiaque optimale malgré une durée prolongée du QRS. / Cardiac Resynchronization Therapy (CRT) is known to decrease mortality rate and improve the quality of life for patients suffering from heart failure with left ventricular contraction dyssynchrony. However, it has been shown that 30% of patients do not respond to this therapy. Many studies have investigated the electrical or mechanical synchronism of contraction but few have studied the activation contraction coupling on a macroscopic level. The objective of this study is to observe the left ventricle’s electromechanical behaviour under biventricular stimulation. A software has been developed to analyse the data coming from non-contact mapping and blood pool SPECT for 12 dogs with heart failure. In order to observe the mechanical response following an electrical activation, we have registered 3D surfaces generated by the 2 modalities. Afterward, we defined the cardiac cycle limits, and we analyzed electrical signals as well as endocardial wall displacement curves where the onset of contraction was defined as a 10% inward radial displacement. Results show that both duration of left ventricular activation and QRS increase with pacing and that electromechanical delays are independent of stimulation mode (mean value 84,56 ± 7,19 ms). Finally, we observed that basolateral stimulation shows the best improvement for left ventricular function while presenting a long QRS duration.