214 research outputs found
Detection of atrial fibrillation in ECG hand-held devices using a random forest classifier
Atrial Fibrillation (AF) is characterized by chaotic electrical impulses in the atria, which leads to irregular heartbeats and can develop blood clots and stroke. Therefore, early detection of AF is crucial for increasing the success rate of the treatment. This study is focused on detection of AF rhythm using hand-held ECG monitoring devices, in addition to three other classes: normal or sinus rhythm, other rhythms, and too noisy to analyze. The pipeline of the proposed method consists of three major components: preprocessing and feature extraction, feature selection, and classification. In total, 491 hand-crafted features are extracted. Then, 150 features are selected in a feature ranking procedure. The selected features are from time, frequency, time-frequency domains, and phase space reconstruction of the ECG signals. In the final stage, a random forest classifier is used to classify the selected features into one of the four aforementioned ECG classes. Using the scoring mechanism provided by PhysioNet/Computing in Cardiology (CinC) Challenge 2017, the overall score (mean±std) of 81.9±2.6% is achieved over the training dataset in 10-fold cross-validation. The proposed algorithm tied for the first place in the PhysioNet/CinC Challenge 2017 with an overall score of 82.6% (rounded to 83%) on the unseen test dataset.Scopu
Classification of Atrial Fibrillation using Random Forest Algorithm
The electrocardiogram is indicates the electrical activity of the heart and it can be used to detect cardiac arrhythmias. In the present work, we exhibited a methodology to classify Atrial Fibrillation (AF), Normal rhythm, and Other abnormal ECG rhythms using a machine learning algorithm by analyzing single-lead ECG signals of short duration. First, the events of ECG signals will be detected, after that morphological features and HRV features are extracted. Finally, these features are applied to the Random Forest classifier to perform classification. The Physionet challenge 2017 dataset with more than 8500 ECG recordings is used to train our model. The proposed methodology yields an F1 score of 0.86, 0.97, and 0.83 respectively in classifying AF, normal, other rhythms, and an accuracy of 0.91 after performing a 5-fold cross-validation
Algorithms for automated diagnosis of cardiovascular diseases based on ECG data: A comprehensive systematic review
The prevalence of cardiovascular diseases is increasing around the world. However, the technology is evolving and can be monitored with low-cost sensors anywhere at any time. This subject is being researched, and different methods can automatically identify these diseases, helping patients and healthcare professionals with the treatments. This paper presents a systematic review of disease identification, classification, and recognition with ECG sensors. The review was focused on studies published between 2017 and 2022 in different scientific databases, including PubMed Central, Springer, Elsevier, Multidisciplinary Digital Publishing Institute (MDPI), IEEE Xplore, and Frontiers. It results in the quantitative and qualitative analysis of 103 scientific papers. The study demonstrated that different datasets are available online with data related to various diseases. Several ML/DP-based models were identified in the research, where Convolutional Neural Network and Support Vector Machine were the most applied algorithms. This review can allow us to identify the techniques that can be used in a system that promotes the patient’s autonomy.N/
Novel Approaches to Pervasive and Remote Sensing in Cardiovascular Disease Assessment
Cardiovascular diseases (CVDs) are the leading cause of death worldwide, responsible
for 45% of all deaths. Nevertheless, their mortality is decreasing in the last decade due to
better prevention, diagnosis, and treatment resources. An important medical instrument
for the latter processes is the Electrocardiogram (ECG).
The ECG is a versatile technique used worldwide for its ease of use, low cost, and
accessibility, having evolved from devices that filled up a room, to small patches or wrist-
worn devices. Such evolution allowed for more pervasive and near-continuous recordings.
The analysis of an ECG allows for studying the functioning of other physiological
systems of the body. One such is the Autonomic Nervous System (ANS), responsible for
controlling key bodily functions. The ANS can be studied by analyzing the characteristic
inter-beat variations, known as Heart Rate Variability (HRV). Leveraging this relation,
a pilot study was developed, where HRV was used to quantify the contribution of the
ANS in modulating cardioprotection offered by an experimental medical procedure called
Remote Ischemic Conditioning (RIC), offering a more objective perspective.
To record an ECG, electrodes are responsible for converting the ion-propagated action
potential to electrons, needed to record it. They are produced from different materials,
including metal, carbon-based, or polymers. Also, they can be divided into wet (if an elec-
trolyte gel is used) or dry (if no added electrolyte is used). Electrodes can be positioned
either inside the body (in-the-person), attached to the skin (on-the-body), or embedded in
daily life objects (off-the-person), with the latter allowing for more pervasive recordings.
To this effect, a novel mobile acquisition device for recording ECG rhythm strips was
developed, where polymer-based embedded electrodes are used to record ECG signals
similar to a medical-grade device.
One drawback of off-the-person solutions is the increased noise, mainly caused by
the intermittent contact with the recording surfaces. A new signal quality metric was
developed based on delayed phase mapping, a technique that maps time series to a
two-dimensional space, which is then used to classify a segment into good or noisy. Two
different approaches were developed, one using a popular image descriptor, the Hu image
moments; and the other using a Convolutional Neural Network, both with promising results for their usage as signal quality index classifiers.As doenças cardiovasculares (DCVs) são a principal causa de morte no mundo, res-
ponsáveis por 45% de todas estas. No entanto, a sua mortalidade tem vindo a diminuir na
última década, devido a melhores recursos na prevenção, diagnóstico e tratamento. Um
instrumento médico importante para estes recursos é o Eletrocardiograma (ECG).
O ECG é uma técnica versátil utilizada em todo o mundo pela sua facilidade de uso,
baixo custo e acessibilidade, tendo evoluÃdo de dispositivos que ocupavam uma sala
inteira para pequenos adesivos ou dispositivos de pulso. Tal evolução permitiu aquisições
mais pervasivas e quase contÃnuas.
A análise de um ECG permite estudar o funcionamento de outros sistemas fisiológi-
cos do corpo. Um deles é o Sistema Nervoso Autônomo (SNA), responsável por controlar
as principais funções corporais. O SNA pode ser estudado analisando as variações inter-
batidas, conhecidas como Variabilidade da Frequência CardÃaca (VFC). Aproveitando essa
relação, foi desenvolvido um estudo piloto, onde a VFC foi utilizada para quantificar a
contribuição do SNA na modulação da cardioproteção oferecida por um procedimento mé-
dico experimental, denominado Condicionamento Isquêmico Remoto (CIR), oferecendo
uma perspectiva mais objetiva.
Na aquisição de um ECG, os elétrodos são os responsáveis por converter o potencial
de ação propagado por iões em eletrões, necessários para a sua recolha. Estes podem
ser produzidos a partir de diferentes materiais, incluindo metal, Ã base de carbono ou
polÃmeros. Além disso, os elétrodos podem ser classificados em húmidos (se for usado um
gel eletrolÃtico) ou secos (se não for usado um eletrólito adicional). Os elétrodos podem
ser posicionados dentro do corpo (dentro-da-pessoa), colocados em contacto com a pele
(na-pessoa) ou embutidos em objetos da vida quotidiana (fora-da-pessoa), sendo que este
último permite gravações mais pervasivas . Para este efeito, foi desenvolvido um novo
dispositivo de aquisição móvel para gravar sinal de ECG, onde elétrodos embutidos Ã
base de polÃmeros são usados para recolher sinais de ECG semelhantes a um dispositivo
de grau médico.
Uma desvantagem das soluções onde os elétrodos estão embutidos é o aumento do
ruÃdo, causado principalmente pelo contato intermitente com as superfÃcies de aquisição. Uma nova métrica de qualidade de sinal foi desenvolvida com base no mapeamento de
fase atrasada, uma técnica que mapeia séries temporais para um espaço bidimensional,
que é então usado para classificar um segmento em bom ou ruidoso. Duas abordagens
diferentes foram desenvolvidas, uma usando um popular descritor de imagem, e outra
utilizando uma Rede Neural Convolucional, com resultados promissores para o seu uso
como classificadores de qualidade de sinal
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