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Electroencephalography (EEG) signal processing for epilepsy and autism spectrum disorder diagnosis

Ibrahim S., Djemal R., Alsuwailem A.

Biocybernetics and Biomedical Engineering

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2018

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Vol. 38, no. 1

16--26

EN

Quantification of abnormality in brain signals may reveal brain conditions and pathologies. In this study, we investigate different electroencephalography (EEG) feature extraction and classification techniques to assist in the diagnosis of both epilepsy and autism spectrum disorder (ASD). First, the EEG signal is pre-processed to remove major artifacts before being decomposed into several EEG sub-bands using a discrete-wavelet-transform (DWT). Two nonlinear methods were studied, namely, Shannon entropy and largest Lyapunov exponent, which measure complexity and chaoticity in the EEG recording, in addition to the two conventional methods (namely, standard deviation and band power). We also study the use of a cross-correlation approach to measure synchronization between EEG channels, which may reveal abnormality in communication between brain regions. The extracted features are then classified using several classification methods. Different EEG datasets are used to verify the proposed design exploration techniques: the University of Bonn dataset, the MIT dataset, the King Abdulaziz University dataset, and our own EEG recordings (46 subjects). The combination of DWT, Shannon entropy, and k-nearest neighbor (KNN) techniques produces the most promising classification result, with an overall accuracy of up to 94.6% for the three-class (multi-channel) classification problem. The proposed method obtained better classification accuracy compared to the existing methods and tested using larger and more comprehensive EEG dataset. The proposed method could potentially be used to assist epilepsy and ASD diagnosis therefore improving the speed and the accuracy.

2

Kinetics of Grain Growth in 718 Ni-Base Superalloy

Huda Z., Zaharinie T., Metselaar H. S. C., Ibrahim S., Min Goh J.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 3

847--852

EN

The Haynes® 718 Ni-base superalloy has been investigated by use of modern material characterization, metallographic and heat treatment equipment. Grain growth annealing experiments at temperatures in the range of 1050 – 1200 oC (1323–1473K) for time durations in the range of 20 min-22h have been conducted. The kinetic equations and an Arrhenius-type equation have been applied to compute the grain-growth exponent n and the activation energy for grain growth, Qg, for the investigated alloy. The grain growth exponent, n, was computed to be in the range of 0.066-0.206; and the n values have been critically discussed in relation to the literature. The activation energy for grain growth, Qg, for the investigated alloy has been computed to be around 440 kJ/mol; and the Qg, data for the investigated alloy has been compared with other metals and alloys and ceramics; and critically analyzed in relation to our results.

PL

Nadstop na bazie niklu Haynes ® 718 badano przy użyciu nowoczesnych urządzeń do charakterystyki materiałów, metalografii i obróbki cieplnej. Przeprowadzono badania wzrostu ziarna podczas wyżarzania w zakresie temperatur 1050 - 1200 ° C (1323-1473K) w czasie trwania od 20 minut do 22 godzin. Równania kinetyczne i równanie typu Arrheniusa zostały zastosowane do obliczania wykładnika wzrostu ziarna n oraz energii aktywacji wzrostu ziarna, Qg, dla badanego stopu. Obliczona wartość wykładnika wzrostu ziarna, n, mieści się w zakresie od 0.066 do 0.206 i została krytycznie przedyskutowana w odniesieniu do literatury. Obliczona energia aktywacji wzrostu ziaren, Qg, wynosi dla badanego stopu na około 440 kJ / mol. Dane Qg dla badanego stopu porównywano z danymi dla innych metali, stopów i ceramiki oraz krytycznie analizowano w odniesieniu do naszych wyników.

3

Synthesis, Thermal Decomposition, Magnetic Properties and Biological Activities of Co(II), Ni(II), Cu(II) and Cd(II) Complexes of Some Triazole-3-thione Schiff Bases

El-Gyar S., El-Gahami M., Abd El-Sameh A., Ibrahim S.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 8

1381-1401

EN

A series of novel complexes of 4-amino-5-benzyl-4H-1,2,4-triazole-3-thione (ABT), 5-benzyl-4-(benzylideneamino)-4H-1,2,4-triazole-3-thione (BBT), 5-benzyl-4-[(2- hydroxybenzylidene)amino]-4H-1,2,4-triazole-3-thione (HBHT) and 5-benzyl-4-[(4- methoxybenzylidene)amino]-4H-1,2,4-triazole-3-thione (BMT) with the divalent ions Co(II), Ni(II), Cu(II) and Cd(II) have been prepared by direct combination of the ligand and metal chloride salt in ethanol. The structures were determined by elemental analysis, molar conductance, magnetic measurements, thermal behaviour, infrared and electronic spectral data. ABT involves N (amino group) and S donor atoms, BBT and BMT involve N (azomethine) and S donor atoms, both act as neutral bidentate ligands. HBHT involves N, O and S donor atoms, acting as monobasic tridentate ligands. The stoichiometry of these complexes is M:L= 1:1 and/or 1:2. The geometry of the complexeswas assigned on the basis of magnetic and electronic spectral data. Tetrahedral and octahedral structures were proposed for the metal complexes. The ligands and their complexes were screened for their antibacterial activity.

4

Modelling of heat conduction problems in a thick layer

Woźniak M., Ibrahim S., Pauk V.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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1998

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z. 6

369-374

EN

Simplified models of a thermoelastic layer resting on a rigid substratum are obtained under tie assumption that the displacement distribution across the layer thickness is approximated using the concept of a decay function, [1], In the present contribution the above approach is applied to a heat conduction problem. The main aim of the approach is to investigate the proper choice of a decay function. The conditions under which the proposed simplified models can be applied are shown.

PL

Uproszczone modele warstwy sprężystej na sztywnym podłożu otrzymuje się przy założeniu, że rozkład przemieszczeń na grubości warstwy jest aproksymowany za pomocą funkcji zanikania, W pracy zastosowano to podejście w zagadnieniu rozkładu temperatury. Głównym celem tego opracowania jest wskazanie odpowiedniego sposobu doboru funkcji zanikania. Podano warunki, przy których zaproponowane modele mogą być stosowane.