Wyniki wyszukiwania - Biblioteka Nauki

1

Automatic detection for epileptic seizure using graph-regularized nonnegative matrix factorization and Bayesian linear discriminate analysis

100%

Mu J. , Dai L. , Liu J.-X. , Shang J. , Xu F. , Liu X. , Yuan S.

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2021

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tom Vol. 41, no. 4

1258--1271

EN

Epilepsy is a neurological disorder characterized by excessive neuronal discharge which results in many problems in terms of behavior, state of mind, consciousness, and can threaten the lives of patients. An automatic epileptic seizure detection method with graph-regularized non-negative matrix factorization (GNMF) and Bayesian linear discriminate analysis (BLDA) is presented in this paper. First, discrete wavelet decomposition is applied to analyze raw electroencephalogram (EEG) signals, and the normalization based on differential operator is used to guarantee the nonnegative constraint and reinforce the distinction between seizure and non-seizure signals. Then, GNMF is employed to dimensionality reduction and feature extraction for EEG data, which could capture a parts-based representation of samples and obtain more discriminative features. The EEG features are calculated and entered into the BLDA classifier for categorized results. The public Freiburg EEG database is used to evaluate the performance of the proposed seizure detection method. The results showed event-based sensitivity of 95.24%, epoch-based sensitivity of 93.20%, and a false-alarm rate of 0.5/h. These results demonstrate the potential clinical value of this method for automatic seizure detection.

2

Detection of epileptic seizures with the use of convolutional neural networks

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Wiszniewski P. , Kołodziej M. , Majkowski A. , Rysz A.

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tom R. 99, nr 2

51--55

EN

The purpose of the article is to investigate whether the implementation of a CNN consisting of several layers will allow the effective detection of epileptic seizures. For the research, a publicly available database registered for 4 dogs and 8 people was used. The 1-second iEEG recordings were marked by a neurophysiologist as interictal, early seizure, and seizure. A CNN was trained for each patient individually. Coefficients such as precision, AUC, sensitivity, and specificity were calculated, and the results were compared with the best algorithms published in one of the contests on the Kaggle platform. The average accuracy for the recognition of seizures using CNN is 0.921, the sensitivity is 0.850, and the specificity is 0.927. For early seizures these values are 0.825, 0.782, and 0.828, respectively.

PL

Celem artykułu było zbadanie czy zastosowanie sieci CNN, składającej się z kilku warstw umożliwi skuteczną detekcję napadów epileptycznych. Na użytek badań zastosowano ogólnodostępną bazę danych zarejestrowaną dla 4 psów oraz 8 ludzi. Jednosekundowe zapisy sygnału iEEG zostały oznaczone przez neurofizjologa jako: międzynapadowe, wczesnonapadowe oraz napadowe. Zaproponowano strukturę sieci CNN, a następnie wytrenowano ją dla każdego pacjenta indywidualnie. Zostały wyliczone współczynniki takie jak: trafność, AUC, czułość, specyficzność. Następnie wyniki zostały porównane do osiągniętych w najlepszych algorytmach opublikowanych w konkursie na platformie Kaggle. Średnia skuteczność rozpoznawania napadów z wykorzystaniem sieci CNN wynosi 0.921, czułość 0.850, a specyficzność 0.927. Dla okresów wczesnonapadowych wartości te wynoszą odpowiednio 0.825, 0.782 i 0.828.

3

Application of empirical mode decomposition and artificial neural network for the classification of normal and epileptic EEG signals

63%

Djemili R. , Bourouba H. , Korba M. C. A.

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tom Vol. 36, no. 1

285--291

EN

Epilepsy is a neurological disorder affecting more than 50 million individuals in the world. Analysis of the electroencephalogram (EEG) is a powerful tool to assist neurologists for diagnosis and treatment. In this paper a new feature extraction method based on empirical mode decomposition (EMD) is proposed. The EEG signal is decomposed into intrinsic mode functions (IMFs) by the EMD algorithm and four statistical parameters are calculated over these IMFs constituting the input feature vector to be fed to a multilayer perceptron neural network (MLPNN) classifier. Experimental results carried out on the publicly available Bonn dataset show that an accurate classification rate of 100% is achieved in the discrimination between normal and ictal EEG, and an accuracy of 97.7% is reached in the classification of interictal and ictal EEG signals. Our results are equivalent or outperform recent studies published in the literature.

4

Wavelet-Hilbert transform based bidirectional least squares grey transform and modified binary grey wolf optimization for the identification of epileptic EEGs

51%

Liu C. , Chen W. , Zhang T.

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tom Vol. 43, no. 2

442--462

EN

Wavelet based seizure detection is an importance topic for epilepsy diagnosis via electroencephalogram (EEG), but its performance is closely related to the choice of wavelet bases. To overcome this issue, a fusion method of wavelet packet transformation (WPT), Hilbert transform based bidirectional least squares grey transform (HTBiLSGT), modified binary grey wolf optimization (MBGWO) and fuzzy K-Nearest Neighbor (FKNN) was proposed. The HTBiLSGTwas first proposed to model the envelope change of a signal, then WPT based HTBiLSGT was developed for EEG feature extraction by performing HTBiLSGT for each subband of each wavelet level. To select discriminative features, MBGWO was further put forward and employed to conduct feature selection, and the selected features were finally fed into FKNN for classification. The Bonn and CHB-MIT EEG datasets were used to verify the effectiveness of the proposed technique. Experimental results indicate the proposed WPT based HTBiLSGT, MBGWO and FKNN can respectively lead to the highest accuracies of 100% and 98.60 ± 1.35% for the ternary and quinary classification cases of Bonn dataset, it also results in the overall accuracy of 99.48 ± 0.61 for the CHB-MIT dataset, and the proposal is proven to be insensitive to the choice of wavelet bases.

5

A new method of cardiac sympathetic index estimation using a 1D-convolutional neural network

44%

Kołodziej M. , Majkowski A. , Tarnowski P. , Rak R. J. , Rysz A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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tom Vol. 69, nr 3

art. no. e136921

EN

Epilepsy is a neurological disorder that causes seizures of many different types. The article presents an analysis of heart rate variability (HRV) for epileptic seizure prediction. Considering that HRV is nonstationary, our research focused on the quantitative analysis of a Poincare plot feature, i.e. cardiac sympathetic index (CSI). It is reported that the CSI value increases before the epileptic seizure. An algorithm using a 1D-convolutional neural network (1D-CNN) was proposed for CSI estimation. The usability of this method was checked for 40 epilepsy patients. Our algorithm was compared with the method proposed by Toichi et al. The mean squared error (MSE) for testing data was 0.046 and the mean absolute percentage error (MAPE) amounted to 0.097. The 1D-CNN algorithm was also compared with regression methods. For this purpose, a classical type of neural network (MLP), as well as linear regression and SVM regression, were tested. In the study, typical artifacts occurring in ECG signals before and during an epileptic seizure were simulated. The proposed 1D-CNN algorithm estimates CSI well and is resistant to noise and artifacts in the ECG signal.