68 results on '"Aydin Akan"'
Search Results
2. Analysis of epileptic EEG signals by using dynamic mode decomposition and spectrum
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Aydin Akan and Ozlem Karabiber Cura
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Quantitative Biology::Neurons and Cognition ,medicine.diagnostic_test ,business.industry ,Computer science ,Physics::Medical Physics ,0206 medical engineering ,Spectrum (functional analysis) ,Biomedical Engineering ,Spectral density ,Pattern recognition ,02 engineering and technology ,Electroencephalography ,020601 biomedical engineering ,Power (physics) ,Matrix decomposition ,Brain Hemisphere ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Dynamic mode decomposition ,Epileptic eeg ,020201 artificial intelligence & image processing ,Artificial intelligence ,business - Abstract
Dynamic mode decomposition (DMD) is a new matrix decomposition method proposed as an iterative solution to problems in fluid flow analysis. Recently, DMD algorithm has successfully been applied to the analysis of non-stationary signals such as neural recordings. In this study, we propose single-channel, and multi-channel EEG based DMD approaches for the analysis of epileptic EEG signals. We investigate the possibility of utilizing the “DMD Spectrum” for the classification of pre-seizure and seizure EEG segments. We introduce higher-order DMD spectral moments and DMD sub-band powers, and extract them as features for the classification of epileptic EEG signals. Experiments are conducted on multi-channel EEG signals collected from 16 epilepsy patients. Single-channel, and multi-channel EEG based DMD approaches have been tested on epileptic EEG data recorded from only right, only left, and both brain hemisphere channels. Performance of various classifiers using the proposed DMD-Spectral based features are compared with that of traditional spectral features. Experimental results reveal that the higher order DMD spectral moments and DMD sub-band power features introduced in this study, outperform the analogous spectral features calculated from traditional power spectrum.
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- 2021
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3. Detection of Consumer Preferences Using EEG Signals
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Burak Ceylan, Aydin Akan, and Serkan Tuzun
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Signal processing ,Channel (digital image) ,medicine.diagnostic_test ,business.industry ,Computer science ,Dashboard (business) ,Neuromarketing ,Mühendislik ,Pattern recognition ,General Medicine ,Electroencephalography ,EEG,EEMD,Empirical mode decomposition,Liking status detection,Neuromarketing ,Hilbert–Huang transform ,Support vector machine ,Engineering ,Mode (computer interface) ,medicine ,Artificial intelligence ,business - Abstract
In this study, a liking estimation system based on electroencephalogram (EEG) signals is developed for neuromarketing applications. The determination of the degree of appreciation of a product by consumers has become an important research topic using machine learning methods. Biological data is recorded while viewing product pictures or videos, then processed by signal processing methods. In this study, 32 channel EEG signals are recorded from subjects who watched two different car advertisement videos and the liking status is determined. After watching the advertisement videos, the participants were asked to vote for the rating of the different images (front view, dashboard, side view, rear view, taillight, logo and grille) of the products. The signals corresponding to these different video regions from the EEG recordings were segmented and analyzed by the Empirical Mode Decomposition (EMD) and Ensemble Empirical Mode Decomposition (EEMD). The statistical features were extracted from Intrinsic Mode Functions (IMF) and the liking status classifications were performed. The classification performance of EMD- and EEMD-based methods are 93.4% and 97.8% respectively on Brand1, and 93.5% and 97.4% respectively on Brand2. In addition, the classification accuracy on both brands combined are 85.1% and 85.7% respectively. The promising results obtained using Support Vector Machines (SVM) show that the proposed EEG-based method may be used in neuromarketing studies.
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- 2020
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4. Epileptic seizure classifications using empirical mode decomposition and its derivative
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Sibel Kocaaslan Atli, Aydin Akan, Hatice Sabiha Türe, and Ozlem Karabiber Cura
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lcsh:Medical technology ,Databases, Factual ,Computer science ,Ensemble empirical mode decomposition ,Feature extraction ,Biomedical Engineering ,02 engineering and technology ,Electroencephalography ,Hilbert–Huang transform ,Biomaterials ,03 medical and health sciences ,Naive Bayes classifier ,0302 clinical medicine ,Seizures ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Feature (machine learning) ,Humans ,Radiology, Nuclear Medicine and imaging ,Empirical mode decomposition ,Epileptic seizure classification ,Epilepsy ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,Research ,Bayes Theorem ,Signal Processing, Computer-Assisted ,Pattern recognition ,General Medicine ,Electroencephalogram (EEG) ,Support vector machine ,lcsh:R855-855.5 ,020201 artificial intelligence & image processing ,Neural Networks, Computer ,Epileptic seizure ,Artificial intelligence ,Intrinsic mode function selection ,medicine.symptom ,business ,030217 neurology & neurosurgery ,Energy (signal processing) - Abstract
Background Epilepsy is one of the most common neurological disorders associated with disruption of brain activity. In the classification and detection of epileptic seizures, electroencephalography (EEG) measurements, which record the electrical activities of the brain, are frequently used. Empirical mode decomposition (EMD) and its derivative, ensemble EMD (EEMD) are recently developed methods used to decompose non-stationary and nonlinear signals such as EEG into a finite number of oscillations called intrinsic mode functions (IMFs). Our main objective in this study is to present a hybrid IMF selection method combining four different approaches (energy, correlation, power spectral distance, and statistical significance measures), and investigate the effect of selected IMFs extracted by EMD and EEMD on the classification. We have applied the proposed IMF selection approach on the classification of EEG signals recorded from epilepsy patients who are under treatment at our collaborator hospital. Multichannel EEG signals collected from epilepsy patients are decomposed into IMFs, and then IMF selection was performed. Finally, time- and spectral-domain, and nonlinear features are extracted and feature sets are created for the classification. Results The maximum classification accuracies obtained using various combinations of IMFs were 94.56%, 95.63%, 96.8%, and 96.25% for SVM, KNN, naive Bayes, and logistic regression classifiers, respectively, by using EMD analysis; whereas, the EEMD approach has provided maximum classification accuracies of 96.06%, 97%, 97%, and 96.25% for SVM, KNN, naive Bayes, and logistic regression, respectively. Classification performance with the same features obtained using direct EEG signals instead of the decomposed IMFs was worse than the aforementioned 2 approaches for every combination. Conclusion Simulation results demonstrate that the proposed IMF selection approach affects the classification results. Also, EEMD provides a robust method for feature extraction from EEG signals in order to classify pre-seizure and seizure segments.
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- 2020
5. A Diagnostic Strategy via Multiresolution Synchrosqueezing Transform on Obsessive Compulsive Disorder
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Ali Olamat, Pinar Ozel, and Aydin Akan
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Obsessive-Compulsive Disorder ,Dependency (UML) ,medicine.diagnostic_test ,Computer Networks and Communications ,Computer science ,business.industry ,Bandwidth (signal processing) ,Pattern recognition ,Electroencephalography ,General Medicine ,Diagnostic strategy ,Instantaneous phase ,Wavelet ,Obsessive compulsive ,Frequency domain ,medicine ,Humans ,Artificial intelligence ,business ,Algorithms - Abstract
This research presents a new method for detecting obsessive–compulsive disorder (OCD) based on time–frequency analysis of multi-channel electroencephalogram (EEG) signals using the multi-variate synchrosqueezing transform (MSST). With the evolution of multi-channel sensor implementations, the employment of multi-channel techniques for the extraction of features arising from multi-channel dependency and mono-channel characteristics has become common. MSST has recently been proposed as a method for modeling the combined oscillatory mechanisms of multi-channel signals. It makes use of the concepts of instantaneous frequency (IF) and bandwidth. Electrophysiological data, like other nonstationary signals, necessitates both joint time–frequency analysis and independent time and frequency domain studies. The usefulness and effectiveness of a multi-variate, wavelet-based synchrosqueezing algorithm paired with a band extraction method are tested using electroencephalography data obtained from OCD patients and control groups in this research. The proposed methodology yields substantial results when analyzing differences between patient and control groups.
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- 2021
6. Analysis of the quadratus lumborum muscle activity on leg length discrepancy: A randomized controlled trial
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Sevim Eryigit, Abdullah Al Kafee, and Aydin Akan
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medicine.medical_specialty ,Physical Therapy, Sports Therapy and Rehabilitation ,Isometric exercise ,Lumbar vertebrae ,Electromyography ,Asymptomatic ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Randomized controlled trial ,law ,Internal medicine ,medicine ,Humans ,Orthopedics and Sports Medicine ,Abdominal Muscles ,Leg ,Lumbar Vertebrae ,medicine.diagnostic_test ,business.industry ,Back Muscles ,Rehabilitation ,Quadratus lumborum muscle ,Leg length ,Lumbosacral Region ,030229 sport sciences ,Leg Length Inequality ,medicine.anatomical_structure ,Cardiology ,Lumbar spine ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
BACKGROUND: Quadratus lumborum (QL) discrete region extensions might change depending on whether leg length discrepancy (LLD) individually has any extra erector spinae action in the lumbar spine, which can result in serious injury to the lower extremities and lumbar vertebrae. OBJECTIVE: This study aims to investigate the effect of QL muscle activity on LLD by using electromyography (EMG) signals. METHODS: The study employed a randomized controlled design. A total of 100 right-handed volunteers were included in this study. All participants were assessed manually by tape measurement for LLD. EMG signals were recorded during the resting and maximal isometric contraction positions to determine QL muscle activity. The power spectral density (PSD) methods were applied to compute EMG signals. RESULTS: In maximal isometric contraction position, comparing the short right LLD (Right side = 0.00064 ± 0.00001, Left side = 0.00033 ± 0.0006) and short left LLD (Right side = 0.00001 ± 0.00008, Left side = 0.00017 ± 0.0001), it was found that the short right LLD group had significantly increased PSD of EMG values. In resting position, the short right LLD (Right side = 0.0002 ± 0.0073, Left side = 0.00016 ± 0.0065) had significantly increased PSD of EMG compared to the short left LLD (Right side = 0.00004 ± 0.0003, Left side = 0.0001 ± 0.0008) values of the QL muscle activity. The results of both groups were also statistically significant (p< 0.05). CONCLUSIONS: The present study showed that it is possible to determine effective experimental interventions for functional LLD using EMG signal analysis of QL muscle activity on an asymptomatic normal population.
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- 2021
7. Emotional state detection based on common spatial patterns of EEG
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Adil Deniz Duru, Merve Dogruyol Basar, and Aydin Akan
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Visual perception ,Spatial filter ,medicine.diagnostic_test ,Computer science ,Speech recognition ,Emotional stimuli ,020206 networking & telecommunications ,Context (language use) ,02 engineering and technology ,Electroencephalography ,ComputingMethodologies_PATTERNRECOGNITION ,Signal Processing ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Spatial ecology ,020201 artificial intelligence & image processing ,State (computer science) ,Electrical and Electronic Engineering ,Decoding methods - Abstract
The application of EEG-based emotional states is one of the most vital phases in the context of neural response decoding. Emotional response mostly appears in the presence of visual, auditory, tactile, and gustatory arousals. In our work, we use visual stimuli to evaluate the emotional feedback. One of the best performing methods in emotion estimation applications is the common spatial patterns (CSP). We implement CSP method in addition to the conventional Welch power spectral density-based analysis. Experimental results and topographies on the collected EEG data show that the CSP spatial filtering method implies the relationship between EEG bands, EEG channels, neural efficiency and emotional stimuli types.
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- 2019
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8. An EEG and Machine Learning based Method for the Detection of Major Depressive Disorder
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Elif Izci, Mehmet Kemal Arikan, Mehmet Akif Ozdemir, Aydin Akan, and Mehmet Akif Ozcoban
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Healthy subjects ,Electroencephalography ,Audiology ,medicine.disease ,Statistical classification ,Mood ,Feature (computer vision) ,Classifier (linguistics) ,medicine ,Major depressive disorder ,business ,Depression (differential diagnoses) - Abstract
Major depressive disorder (MDD) is a common mood disorder encountered worldwide. Early diagnosis has great importance to prevent the negative effects on the person. The aim of this study is to develop an objective method to differentiate MDD patients from healthy controls. Electroencephalography (EEG) signals taken from 16 MDD patients and 16 healthy subjects are analyzed according to the regions of the brain, and time-domain, frequency-domain, and nonlinear features were extracted. The feature sets are classified using five different classification algorithms. As a result of the study, a classification accuracy of 89.5% was yielded using the Bagging classifier with 7 features calculated from the central EEG channels.
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- 2021
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9. Epileptic EEG Classification by Using Time-Frequency Images for Deep Learning
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Mehmet Akif Ozdemir, Aydin Akan, and Ozlem Karabiber Cura
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Computer Networks and Communications ,Computer science ,02 engineering and technology ,Electroencephalography ,Convolutional neural network ,03 medical and health sciences ,Epilepsy ,0302 clinical medicine ,Deep Learning ,Seizures ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Epileptic eeg ,Humans ,medicine.diagnostic_test ,business.industry ,Deep learning ,Pattern recognition ,General Medicine ,medicine.disease ,Time–frequency analysis ,Seizure detection ,020201 artificial intelligence & image processing ,Artificial intelligence ,Neural Networks, Computer ,business ,030217 neurology & neurosurgery ,Energy (signal processing) - Abstract
Epilepsy is one of the most common brain disorders worldwide. The most frequently used clinical tool to detect epileptic events and monitor epilepsy patients is the EEG recordings. There have been proposed many computer-aided diagnosis systems using EEG signals for the detection and prediction of seizures. In this study, a novel method based on Fourier-based Synchrosqueezing Transform (SST), which is a high-resolution time-frequency (TF) representation, and Convolutional Neural Network (CNN) is proposed to detect and predict seizure segments. SST is based on the reassignment of signal components in the TF plane which provides highly localized TF energy distributions. Epileptic seizures cause sudden energy discharges which are well represented in the TF plane by using the SST method. The proposed SST-based CNN method is evaluated using the IKCU dataset we collected, and the publicly available CHB-MIT dataset. Experimental results demonstrate that the proposed approach yields high average segment-based seizure detection precision and accuracy rates for both datasets (IKCU: 98.99% PRE and 99.06% ACC; CHB-MIT: 99.81% PRE and 99.63% ACC). Additionally, SST-based CNN approach provides significantly higher segment-based seizure prediction performance with 98.54% PRE and 97.92% ACC than similar approaches presented in the literature using the CHB-MIT dataset.
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- 2021
10. Epileptic EEG Classification Using Synchrosqueezing Transform with Machine and Deep Learning Techniques
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Ozlem Karabiber Cura, Mehmet Akif Ozdemir, and Aydin Akan
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medicine.diagnostic_test ,Computer science ,business.industry ,Deep learning ,020206 networking & telecommunications ,Pattern recognition ,02 engineering and technology ,Image segmentation ,Electroencephalography ,medicine.disease ,Convolutional neural network ,Support vector machine ,Naive Bayes classifier ,Epilepsy ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,020201 artificial intelligence & image processing ,Artificial intelligence ,Representation (mathematics) ,business - Abstract
Epilepsy is a neurological disease that is very common worldwide. In the literature, patient’s electroencephalography (EEG) signals are frequently used for an epilepsy diagnosis. However, the success of epileptic examination procedures from quantitative EEG signals is limited. In this paper, a high-resolution time-frequency (TF) representation called Synchrosqueezed Transform (SST) is used to classify epileptic EEG signals. The SST matrices of seizure and pre-seizure EEG data of 16 epilepsy patients are calculated. Two approaches based on machine learning and deep learning are proposed to classify pre-seizure and seizure signals. In the machine learning-based approach, the various features like higher-order joint moments are calculated and these features are classified by Support Vector Machine (SVM), k-Nearest Neighbor (kNN) and Naive Bayes (NB) classifiers. In the deep learning-based approach, the SST matrix was recorded as an image and a Convolutional Neural Network (CNN)-based architecture was used to classify these images. Simulation results demonstrate that both approaches achieved promising validation accuracy rates. While the maximum (90.2%) validation accuracy is achieved for the machine learning-based approach, (90.3%) validation accuracy is achieved for the deep learning-based approach.
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- 2021
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11. A Dynamic Mode Decomposition Based Approach for Epileptic EEG Classification
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Aydin Akan, Ozlem Karabiber Cura, Mehmet Akif Ozdemir, and Sude Pehlivan
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Signal processing ,medicine.diagnostic_test ,business.industry ,Computer science ,Feature extraction ,020206 networking & telecommunications ,Pattern recognition ,02 engineering and technology ,Electroencephalography ,medicine.disease ,Signal ,Epilepsy ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Dynamic mode decomposition ,Epileptic eeg ,020201 artificial intelligence & image processing ,Artificial intelligence ,business - Abstract
Epilepsy is a neurological disorder that affects many people all around the world, and its early detection is a topic of research widely studied in signal processing community. In this paper, a new technique that was introduced to solve problems of fluid dynamics called Dynamic Mode Decomposition (DMD), is used to classify seizure and non-seizure epileptic EEG signals. The DMD decomposes a given signal into the intrinsic oscillations called modes which are used to define a DMD spectrum. In the proposed approach, the DMD spectrum is obtained by applying either multi-channel or single-channel based DMD technique. Then, subband and total power features extracted from the DMD spectrum and various classifiers are utilized to classify seizure and non-seizure epileptic EEG segments. Outstanding classification results are achieved by both the single-channel based (96.7%), and the multi-channel based (96%) DMD approaches.
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- 2021
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12. EEG based Epileptic Seizures Detection using Intrinsic Time-Scale Decomposition
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Murside Degirmenci and Aydin Akan
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medicine.diagnostic_test ,Computer science ,business.industry ,Feature extraction ,Pattern recognition ,Electroencephalography ,Linear discriminant analysis ,medicine.disease ,Support vector machine ,Naive Bayes classifier ,Epilepsy ,medicine ,Epileptic seizure ,Artificial intelligence ,medicine.symptom ,Entropy (energy dispersal) ,business - Abstract
Epilepsy is a type of neurological disorder that causes abnormal brain activities and creates epileptic seizures. Traditionally epileptic seizure prediction is realized with a visual examination of Electroencephalogram (EEG) signals. But this technique needs a long time EEG monitoring. So, the automatic epileptic seizures prediction schemes become a requirement at this point. This study proposes a method to classify epileptic seizures and normal EEG data by utilizing the Intrinsic Time-scale Decomposition (ITD)-based features. The dataset has been supplied from the database of the Epileptology Department of Bonn University. It contains 5 data groups A, B, C, D, E. The study aims to classify healthy and epileptic data, so data of groups A and E are used to perform evaluations of proposed methods. The EEG data are decomposed into Proper Rotation Components (PRCs) by ITD. The feature extraction methods are applied to the first five PRCs of each EEG data from healthy and epileptic individuals. These features are classified using K-Nearest Neighbors (KNN), Linear Discriminant Analysis (LDA), Naive Bayes, Support Vector Machine (SVM) and Logistic Regression classifiers. The results demonstrated that the epileptic data is differentiated from normal data by applying the nonlinear ITD with outstanding classification performance.
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- 2020
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13. EMG based Hand Gesture Recognition using Deep Learning
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Mehmet Akif Ozdemir, Deniz Hande Kisa, Onan Guren, Aydin Akan, and Aytuğ Onan
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medicine.diagnostic_test ,Computer science ,business.industry ,Deep learning ,Short-time Fourier transform ,Pattern recognition ,Electromyography ,Convolutional neural network ,Gesture recognition ,medicine ,Spectrogram ,Ulnar deviation ,Artificial intelligence ,business ,Gesture - Abstract
The Electromyography (EMG) signal is a nonstationary bio-signal based on the measurement of the electrical activity of the muscles. EMG based recognition systems play an important role in many fields such as diagnosis of neuromuscular diseases, human-computer interactions, console games, sign language detection, virtual reality applications, and amputee device controls. In this study, a novel approach based on deep learning has been proposed to improve the accuracy rate in the prediction of hand movements. Firstly, 4-channel surface EMG (sEMG) signals have been measured while simulating 7 different hand gestures (Extension, Flexion, Open Hand, Punch, Radial Deviation, Rest, and Ulnar Deviation) from 30 participants. The obtained sEMG signals have been segmented into sections where each movement was found. Then, spectrogram images of the segmented sEMG signals have been created by means of ShortTime Fourier Transform (STFT). The created colored spectrogram images have trained with 50-layer Convolutional Neural Network (CNN) based on Residual Networks (ResNet) architecture. Owing to the proposed method, test accuracy of 99.59% and F1 Score of 99.57% have achieved for 7 different hand gesture classifications.
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- 2020
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14. Comparison of Parallel Magnetic Resonance Imaging Algorithms: PILS and SENSE
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Onan Guren, Egehan Dorum, Aydin Akan, and Mazlum Unay
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medicine.diagnostic_test ,Computer science ,Image quality ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Magnetic resonance imaging ,Sense (electronics) ,Iterative reconstruction ,Software ,medicine ,Parallel magnetic resonance imaging ,Sensitivity (control systems) ,MATLAB ,business ,Algorithm ,computer ,computer.programming_language - Abstract
Magnetic Resonance (MR) imaging has always followed a developmental path by incorporating new algorithms in terms of image quality and imaging duration. In MR imaging performed in hospitals and clinics, the duration of imaging is an important consideration in terms of both for the comfort of the patient and the number of patients who can be taken daily. One of the approaches to shorten the imaging time is the parallel imaging method. After parallel imaging algorithms started being used, imaging duration up to 1 hour with traditional methods has been reduced to minutes or even seconds depending on the number of receiving coils and the type of algorithm used. In this paper; comparison of the widely used parallel imaging algorithms such as Partially Parallel Imaging With Localized Sensitivities (PILS), and Sensitivity Encoding (SENSE) and evaluation of advantages and disadvantages of these algorithms over each other were performed utilizing the numerical calculation software named MATLAB.
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- 2020
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15. Individual-based Estimation of Valence with EEG
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Aydin Akan, Tamer Demiralp, Bora Cebeci, and Miray Erbey
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medicine.diagnostic_test ,business.industry ,Feature extraction ,Pattern recognition ,Feature selection ,Electroencephalography ,Independent component analysis ,Cross-validation ,Multilayer perceptron ,medicine ,Spectrogram ,Artificial intelligence ,Valence (psychology) ,business ,Mathematics - Abstract
In this study, it is determined individual-based features which are used to estimate emotional negative valence and compared the features effectiveness with different classifiers. Ten movie clips are shown to subjects as an emotional stimuli and EEG recording is recorded synchronously. Emotional valence value is scored in [–7 7] Likert scale by the subjects immediately after video ended. According to lowest and highest valence values, two classes are generated. The data is processed on an individual basis and personal spatial filters is obtained by Independent Component Analysis. After calculating the spectrogram of the spatial filtered data, features are extracted by subtracting amplitudes of 3Hz averaged frequency bands. The result of feature selection, it is observed that features from beta and gamma bands are much more effective. The success rate of the selected features was tested with five classifiers by cross validation, and high performance was obtained from multilayer perceptron classifiers and the instance- based k-nearest neighborhood algorithm (IBk-NN). The average accuracies of IBk-NN and multilayer classifier are achieved 86% ±8 and 83% ±9, respectively.
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- 2020
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16. Epileptic EEG Classification Using Synchrosqueezing Transform and Machine Learning
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Ozlem Karabiber Cura and Aydin Akan
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medicine.diagnostic_test ,Computer science ,business.industry ,Feature extraction ,Decision tree ,Image segmentation ,Electroencephalography ,Machine learning ,computer.software_genre ,medicine.disease ,Time–frequency analysis ,Data set ,Epilepsy ,medicine ,Artificial intelligence ,business ,computer ,Continuous wavelet transform - Abstract
Epilepsy is one of the neurological diseases that occur incidences worldwide. The electroencephalography (EEG) recording method is the most frequently used clinical practice in the diagnosis and monitoring of epilepsy. Many computer-aided analysis methods have been developed in the literature to facilitate the analysis of long-term EEG signals. In the proposed study, the patient-based seizure detection approach is proposed using a high-resolution time-frequency (TF) representation named Synchrosqueezed Transform (SST) method. The SST of two different data sets called the IKCU data set and CHB-MIT data set are obtained, and Higher-order joint TF(HOJ-TF) based and Gray-level co-occurrence matrix (GLCM) based features are calculated using these SSTs. Using some machine learning methods such as Decision Tree (DT), k-Nearest Neighbor (kNN), and Logistic Regression (LR), classification processes are conducted. High patient-based seizure detection success is achieved for both the IKCU data set (94.25%) and the CHB-MIT data set (95.15%).
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- 2020
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17. An EEG Based Liking Status Detection Method for Neuromarketing Applications
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Serkan Tuzun, Burak Ceylan, and Aydin Akan
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Facial expression ,medicine.diagnostic_test ,business.industry ,Computer science ,Feature extraction ,Neuromarketing ,Pattern recognition ,02 engineering and technology ,Electroencephalography ,Support vector machine ,03 medical and health sciences ,0302 clinical medicine ,Mode (computer interface) ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Eye tracking ,020201 artificial intelligence & image processing ,030212 general & internal medicine ,Artificial intelligence ,business ,Skin conductance - Abstract
In this study, an estimation system based on electroencephalogram (EEG) signals has been developed for use in neuromarketing applications. Determination of the degree of consumer liking a product by processing the biological data (EEG, facial expressions, eye tracking, Galvanic skin response, etc.) recorded while viewing the product images or videos has become an important research topic. In this study, 32-channel EEG signals were recorded from subjects while they watch two different car advertisement videos, and the liking status was determined. After watching the car commercial videos, the subjects were asked to vote on the rating of different images (front view, front console, side view, rear view, rear light, logo and front grill) of the cars. The signals corresponding to these different video regions from the EEG recordings were segmented and analyzed by the Empirical Mode Decomposition (EMD) method. Several statistical features were extracted from the resulting Intrinsic Mode Functions and the liking status classification was performed. Classification results obtained with Support Vector Machines (SVM) classifiers indicate that the proposed EEG-based liking detection method may be used in neuromarketing studies.
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- 2020
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18. Classification of Epileptic EEG Signals Using Dynamic Mode Decomposition
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Sude Pehlivan, Aydin Akan, and Ozlem Karabiber Cura
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Signal processing ,medicine.diagnostic_test ,Computer science ,business.industry ,Pattern recognition ,02 engineering and technology ,Electroencephalography ,medicine.disease ,Hilbert–Huang transform ,03 medical and health sciences ,Epilepsy ,0302 clinical medicine ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Dynamic mode decomposition ,Epileptic eeg ,020201 artificial intelligence & image processing ,Epileptic seizure ,Artificial intelligence ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
In the literature, several signal processing techniques have been used to diagnose epilepsy which is a nervous system disease. However most of these techniques fail to analyse EEG signals which are dynamic and non-linear. In this study, an approach which utilizes a data-driven technique called Dynamic Mode Decomposition (DMD) that was originally developed to be used in fluid mechanics was proposed. Features that were belonged to EEG signals were calculated using DMD method and with the help of different classifiers, classification of the preseizure and seizure EEG signals was performed. Obtained results showed that the proposed method presented an alternative to approaches that are based on Empirical Mode Decomposition and its derivatives.
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- 2020
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19. ECG Arrhythmia Detection with Deep Learning
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Mehmet Akif Ozdemir, Murside Degirmenci, Elif Izci, and Aydin Akan
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medicine.diagnostic_test ,Heartbeat ,Computer science ,business.industry ,Deep learning ,0206 medical engineering ,Pattern recognition ,02 engineering and technology ,020601 biomedical engineering ,Signal ,Heart Rhythm ,Heart rate ,cardiovascular system ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Heart beat ,020201 artificial intelligence & image processing ,cardiovascular diseases ,Artificial intelligence ,business ,Electrocardiography - Abstract
Arrhythmia is any irregularity of heart rate that cause an abnormality in your heart rhythm. Manual analysis of Electrocardiogram (ECG) signal is not enough for quickly identify abnormalities in the heart rhythm. This paper proposes a deep learning approach for detection of five different arrhythmia types based on 2D convolutional neural networks (CNN) architecture. ECG signals were obtained from MIT-BIH arrhythmia database. For CNN architecture, each ECG signal was segmented into heartbeats, then each heartbeat was transformed into 2D grayscale heartbeat image. 2D CNN model was used due to success of image recognition. The proposed model result demonstrate that CNN and ECG image formation give highest result when classified different types of ECG arrhythmic signals.
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- 2020
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20. Estimation of Emotion Status Using IAPS Image Data Set
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Aydin Akan, Mehmet Tugay Bahar, Leyla Nur Turhal, Bartu Yesilkaya, and Onan Guren
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0303 health sciences ,medicine.diagnostic_test ,Computer science ,business.industry ,Feature vector ,Interface (computing) ,Pattern recognition ,02 engineering and technology ,Electroencephalography ,021001 nanoscience & nanotechnology ,Image (mathematics) ,Time–frequency analysis ,Support vector machine ,Data set ,03 medical and health sciences ,ComputingMethodologies_PATTERNRECOGNITION ,medicine ,Emotion recognition ,Artificial intelligence ,0210 nano-technology ,business ,030304 developmental biology - Abstract
Emotion recognition is an effective analysis method used to increase the interaction between human-machine interface. EEG based emotion recognition studies based on brain signals are preferred in order to provide healthy results of emotion analysis experiments. In this study, emotion recognition analysis was performed in accordance with dimensional emotion modelling. Data cleaning was performed by applying the necessary filters on the recorded data. The feature vector was then created and the success rate was determined using support vector machines and classification methods such as K-nearest neighbour.
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- 2020
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21. EEG Based Mental Workload Estimation System
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Tamer Demiralp, Aydin Akan, Bora Cebeci, and Bernis Sutcubasi
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Estimation ,medicine.diagnostic_test ,Computer science ,Speech recognition ,medicine ,Workload ,Electroencephalography - Published
- 2020
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22. Intrinsic Synchronization Analysis of Brain Activity in Obsessive-compulsive Disorders
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Ali Karaca, Oguz Tan, Mehmet Akif Ozcoban, Ali Olamat, Pinar Ozel, and Aydin Akan
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Obsessive-Compulsive Disorder ,Computer Networks and Communications ,Computer science ,Brain activity and meditation ,Electroencephalography Phase Synchronization ,Electroencephalography ,050105 experimental psychology ,03 medical and health sciences ,0302 clinical medicine ,Synchronization (computer science) ,Similarity (psychology) ,medicine ,Humans ,0501 psychology and cognitive sciences ,Signal processing ,medicine.diagnostic_test ,business.industry ,Visibility graph ,05 social sciences ,Brain ,Pattern recognition ,Signal Processing, Computer-Assisted ,General Medicine ,Coherence (statistics) ,Models, Theoretical ,Nonlinear system ,Artificial intelligence ,business ,030217 neurology & neurosurgery - Abstract
Obsessive–compulsive disorder (OCD) is one of the neuropsychiatric disorders qualified by intrusive and iterative annoying thoughts and mental attitudes that are activated by these thoughts. In recent studies, advanced signal processing techniques have been favored to diagnose OCD. This research suggests four different measurements; intrinsic phase-locked value, intrinsic coherence, intrinsic synchronization likelihood, and intrinsic visibility graph similarity that quantifies the synchronization level and complexity in electroencephalography (EEG) signals. This intrinsic synchronization is achieved by utilizing Multivariate Empirical Mode Decomposition (MEMD), a data-driven method that resolves nonlinear and nonstationary data into their intrinsic mode functions. Our intrinsic technique in this study demonstrates that MEMD-based synchronization analysis gives us much more detailed knowledge rather than utilizing the synchronization method alone. Furthermore, the nonlinear synchronization method presents more consistent results considering OCD heterogeneity. Statistical evaluation using sample [Formula: see text]-test and [Formula: see text]-test has shown the significance of such new methodology.
- Published
- 2020
23. EEG-Based Emotion Recognition with Deep Convolutional Neural Networks
- Author
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Aydin Akan, Elif Izci, Murside Degirmenci, and Mehmet Akif Ozdemir
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medicine.diagnostic_test ,business.industry ,Computer science ,Deep learning ,0206 medical engineering ,Biomedical Engineering ,Pattern recognition ,02 engineering and technology ,Electroencephalography ,020601 biomedical engineering ,Brain mapping ,Convolutional neural network ,Arousal ,Low arousal theory ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,020201 artificial intelligence & image processing ,Artificial intelligence ,Valence (psychology) ,business ,Spatial analysis - Abstract
The emotional state of people plays a key role in physiological and behavioral human interaction. Emotional state analysis entails many fields such as neuroscience, cognitive sciences, and biomedical engineering because the parameters of interest contain the complex neuronal activities of the brain. Electroencephalogram (EEG) signals are processed to communicate brain signals with external systems and make predictions over emotional states. This paper proposes a novel method for emotion recognition based on deep convolutional neural networks (CNNs) that are used to classify Valence, Arousal, Dominance, and Liking emotional states. Hence, a novel approach is proposed for emotion recognition with time series of multi-channel EEG signals from a Database for Emotion Analysis and Using Physiological Signals (DEAP). We propose a new approach to emotional state estimation utilizing CNN-based classification of multi-spectral topology images obtained from EEG signals. In contrast to most of the EEG-based approaches that eliminate spatial information of EEG signals, converting EEG signals into a sequence of multi-spectral topology images, temporal, spectral, and spatial information of EEG signals are preserved. The deep recurrent convolutional network is trained to learn important representations from a sequence of three-channel topographical images. We have achieved test accuracy of 90.62% for negative and positive Valence, 86.13% for high and low Arousal, 88.48% for high and low Dominance, and finally 86.23% for like–unlike. The evaluations of this method on emotion recognition problem revealed significant improvements in the classification accuracy when compared with other studies using deep neural networks (DNNs) and one-dimensional CNNs.
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- 2020
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24. Seizure onset detection based on frequency domain metric of empirical mode decomposition
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Ahmet Can Mert and Aydin Akan
- Subjects
medicine.diagnostic_test ,Computer science ,business.industry ,Feature vector ,Mode (statistics) ,020206 networking & telecommunications ,Pattern recognition ,02 engineering and technology ,Electroencephalography ,Hilbert–Huang transform ,Seizure onset ,Frequency domain ,Signal Processing ,Metric (mathematics) ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,020201 artificial intelligence & image processing ,Artificial intelligence ,Electrical and Electronic Engineering ,business ,Energy (signal processing) - Abstract
This paper explores the data-driven properties of the empirical mode decomposition (EMD) for detection of epileptic seizures. A new method in frequency domain is presented to analyze intrinsic mode functions (IMFs) decomposed by EMD. They are used to determine whether the electroencephalogram (EEG) recordings contain seizure or not. Energy levels of the IMFs are extracted as threshold level to detect the changes caused by seizure activity. A scalar value energy resulting from the energy levels is individually used as an indicator of the epileptic EEG without the requirements of multidimensional feature vector and complex machine learning algorithms. The proposed methods are tested on different EEG recordings to evaluate the effectiveness of the proposed method and yield accuracy rate up to 97.89%.
- Published
- 2018
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25. Emotion Recognition with Multi-Channel EEG Signals Using Auditory Stimulus
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Mehmet Akif Ozdemir, Cansu Gunes, and Aydin Akan
- Subjects
Signal processing ,medicine.diagnostic_test ,Computer science ,business.industry ,Feature vector ,Feature extraction ,Pattern recognition ,Stimulus (physiology) ,Electroencephalography ,Hilbert–Huang transform ,Arousal ,medicine ,Artificial intelligence ,Valence (psychology) ,business - Abstract
Emotions play a significant role in daily life by encouraging the individual in the survival, decision making, guessing, and communication processes. Through emotions can be explained with the activation of anatomical structures in certain regions of brain with nervous system the emotions can be understood by electroencephalogram (EEG) signals. In order to recognize emotions, the signal processing techniques were applied to recorded signals using 32-channels EEG device from the subjects during listening audios. The Self-Assessment Manikin (SAM) form was filled by 23 subjects to evaluate their feelings based on three emotion states and recorded their answers by designed Graphical User Interface (GUI) monitored in front of the subjects. In signal processing stage, the EEG signals were segmented into segmented files by cutting stimulus intervals from recorded signal and decomposed to Intrinsic Mode Functions (IMFs) by Empirical Mode Decomposition (EMD) method. Then, most meaningful IMFs has been selected by analyzing Power Spectral Density (PSD) to extract statistical and entropy-based features and then, classification algorithm has been applied to obtain feature vector to categorize states of emotion consisting of valence, arousal, dominance dimensions. It is aimed to find most useful selected IMFs, most active channels related to emotion, best suitable features for each dimension of emotion. Finally, the percentage of performance accuracy has been calculated and the best accuracy of 81.74% is found in channels ranged in frontal lobe (1–12) for valence state, 72.15% in channel TP7 for arousal state, 74.57% in channels ranged in frontal lobe (1–12) for dominance state by combining different features.
- Published
- 2019
26. Comparison of IMF Selection Methods in Classification of Multiple Sclerosis EEG Data
- Author
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Jeroen Van Schependom, Soner Kotan, Aydin Akan, and Guy Nagels
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medicine.diagnostic_test ,business.industry ,Computer science ,Spectral density ,Pattern recognition ,Electroencephalography ,Hilbert–Huang transform ,Random forest ,Correlation ,Nonlinear system ,Amplitude ,medicine ,Artificial intelligence ,business ,Classifier (UML) - Abstract
Empirical mode decomposition (EMD) method is a powerful tool in the analysis of of nonlinear and nonstationary signals. It decomposes signals into a number of amplitude and frequency modulated signals namely intrinsic mode functions (IMFs). However, some of these IMFs represents the original signal better while some of them are useless. IMF selection methods are suggested to determine the IMFs which represents the original signal better than other IMFs. In this study, we analyzed the effect of IMF selection methods in classification performance. We compared power based, correlation based and power spectral density based IMF selection methods in the classification of the electroencephalography (EEG) signals, which are collected from subjects with multiple sclerosis. The EEG signals are classified as the patients are being cognitively impaired or intact. k-nearest neighbors, multilayer perceptron neural networks and random forest classifiers are used in classification. The results show that, effect of IMF selection methods on accuracy is changeable in regard to classifier preference.
- Published
- 2019
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27. Control of Serious Games Designed for Alzheimer's and Dementia Patients by EEG Signals
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Ozlem Karabiber Cura, Ahmet Ata, Aydin Akan, and Bartu Yesilkaya
- Subjects
medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Serious game ,Disease ,Electroencephalography ,medicine.disease ,Physical medicine and rehabilitation ,Medicine ,Dementia ,business ,Control (linguistics) ,human activities ,Brain–computer interface - Abstract
Alzheimer's Disease and Dementia are increasing diseases with the aging population. These diseases cause memory loss, impaired attention, impaired problem-solving abilities. Serious games are designed to prevent or slow the progression of these diseases and to reduce the effects of diseases. In this study, a 2-dimensional maze game is designed as a serious game. The purpose of this study is to play the game by using EEG signals recording from the user.
- Published
- 2019
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28. Investigation of Emotional Changes Using Features of EEG-Gamma Band and Different Classifiers
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Aydin Akan, Merve Dogruyol Basar, and Adil Deniz Duru
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Signal processing ,medicine.diagnostic_test ,Emotional Changes ,Computer science ,Frequency band ,Speech recognition ,Interface (computing) ,medicine ,Spectral density ,Electroencephalography ,Gamma band ,Brain–computer interface - Abstract
This study focuses on a signal processing method, which qualifies the relation between the emotional stimulation and emotional changes in healthy participants. For this purpose, an emotional EEG-based database was created by using stimuli which represented to the participants by using Nencki Affective Picture System (NAPS) for the scope of this study. Then, signal processing which includes Power Spectral Density (PSD) and a number of classification analysis is investigated. PSD was analyzed for the emotion connectivity between three types of emotional stimuli to the sub frequency band (gamma band) of the collected EEG-based data. In recent times, most of the studies commonly concentrated on the Brain-Computer Interface (BCI) and we aim that this study performed on emotional changes analyses based BCI systems will be estimable work for the researchers working in this scope.
- Published
- 2019
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29. Frontal Synchronization Biases in Obsessive-Compulsive Disorders
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Mehmet Akif Ozcoban and Aydin Akan
- Subjects
medicine.diagnostic_test ,Cognition ,Electroencephalography ,behavioral disciplines and activities ,Neuropsychiatric disorder ,Obsessive-compulsive disorders ,Frontal lobe ,Neuroimaging ,Obsessive compulsive ,mental disorders ,Synchronization (computer science) ,medicine ,Psychology ,Neuroscience - Abstract
Obsessive Compulsive Disorder (OCD) is one of the most common neuropsychiatric disorder in the community. Several neuroimaging systems shows that OCD causes functional disorders in the frontal lobe. In this study, the effects of the OCD on the frontal part are investigated with Inter-Channels Phase Clustering (ICPC) method. According to the Significant desynchronization was detected in slow EEG bands for 7 electrodes on the frontal lobe. These findings are consistent with the previous results that obtained by other neuroimaging devices. The results are also showed that loss of frontal synchronization cause functional disconnectivity. In addition to this, it can be concluded that OCD may cause many cognitive dysfunctions, such as loss of memory.
- Published
- 2019
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30. EEG based Emotional State Estimation using 2-D Deep Learning Technique
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Murside Degirmenci, Onan Guren, Aydin Akan, and Mehmet Akif Ozdemir
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medicine.diagnostic_test ,Artificial neural network ,Computer science ,business.industry ,Azimuthal equidistant projection ,Deep learning ,Pattern recognition ,Electroencephalography ,Convolutional neural network ,Low arousal theory ,medicine ,Artificial intelligence ,State (computer science) ,Valence (psychology) ,business - Abstract
Emotion detection is very crucial role on diagnosis of brain disorders and psychological disorders. Electroencephalogram (EEG) is useful tool that obtain complex physiological brain signals from human. In this paper, we proposed a novel approach for emotional state estimation using convolutional neural network (CNN) based deep learning technique from EEG signals. Firstly, we convert 32 lead EEG signals to 2D EEG images with Azimuthal Equidistant Projection (AEP) technique. Then, 2D images that represented measurements of EEG signals sent to CNN based deep neural network for classification. In this study, we have achieved accuracy of 95.96% two classes as negative and positive valence, 96.09% two classes as high and low arousal and 95.90% two classes as high and low arousal dominance.
- Published
- 2019
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31. Classification of Epileptic EEG Signals Using Synchrosqueezing Transform and Machine Learning
- Author
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Aydin Akan and Ozlem Karabiber Cura
- Subjects
Computer Networks and Communications ,Computer science ,02 engineering and technology ,Electroencephalography ,Machine Learning ,03 medical and health sciences ,Naive Bayes classifier ,Epilepsy ,0302 clinical medicine ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Humans ,medicine.diagnostic_test ,business.industry ,Short-time Fourier transform ,Bayes Theorem ,Signal Processing, Computer-Assisted ,Pattern recognition ,General Medicine ,medicine.disease ,Ensemble learning ,Data set ,Support vector machine ,020201 artificial intelligence & image processing ,Epileptic seizure ,Artificial intelligence ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Epilepsy is a neurological disease that is very common worldwide. Patient’s electroencephalography (EEG) signals are frequently used for the detection of epileptic seizure segments. In this paper, a high-resolution time-frequency (TF) representation called Synchrosqueezing Transform (SST) is used to detect epileptic seizures. Two different EEG data sets, the IKCU data set we collected, and the publicly available CHB-MIT data set are analyzed to test the performance of the proposed model in seizure detection. The SST representations of seizure and nonseizure (pre-seizure or inter-seizure) EEG segments of epilepsy patients are calculated. Various features like higher-order joint TF (HOJ-TF) moments and gray-level co-occurrence matrix (GLCM)-based features are calculated using the SST representation. By using single and ensemble machine learning methods such as k-Nearest Neighbor (kNN), Logistic Regression (LR), Naive Bayes (NB), Support Vector Machine (SVM), Boosted Trees (BT), and Subspace kNN (S-kNN), EEG features are classified. The proposed SST-based approach achieved 95.1% ACC, 96.87% PRE, 95.54% REC values for the IKCU data set, and 95.13% ACC, 93.37% PRE, 90.30% REC values for the CHB-MIT data set in seizure detection. Results show that the proposed SST-based method utilizing novel TF features outperforms the short-time Fourier transform (STFT)-based approach, providing over 95% accuracy for most cases, and compares well with the existing methods.
- Published
- 2021
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32. Emotion recognition from EEG signals by using multivariate empirical mode decomposition
- Author
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Ahmet Can Mert and Aydin Akan
- Subjects
Multivariate empirical mode decomposition ,medicine.diagnostic_test ,Computer science ,business.industry ,Speech recognition ,020206 networking & telecommunications ,02 engineering and technology ,Electroencephalography ,Work in process ,computer.software_genre ,Hilbert–Huang transform ,Artificial Intelligence ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Snapshot (computer storage) ,020201 artificial intelligence & image processing ,Computer Vision and Pattern Recognition ,SIMD ,Artificial intelligence ,Emotion recognition ,business ,computer ,Natural language processing - Abstract
This is the artifact for the paper titled "POKER: Permutation-based SIMD Execution of Intensive Tree Search by Path Encoding" accepted at CGO 2018. This artifact helps reproduce the results presented in Figures 7 - 9 and Tables 2 - 3 in Section 4. For more information on how to use it, please refer to our paper and the README.txt file in this package. Please note that POKER is a work in progress. This artifact is a snapshot of this work and thus is only applicable under the experimental settings described in this paper. Please feel free to contact the authors if you have any questions.
- Published
- 2016
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33. Arrhythmia Detection on ECG Signals by Using Empirical Mode Decomposition
- Author
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Mehmet Akif Ozdemir, Aydin Akan, Elif Izci, and Reza Sadighzadeh
- Subjects
medicine.diagnostic_test ,Heart disease ,Computer science ,business.industry ,Left bundle branch block ,Feature extraction ,Pattern recognition ,Right bundle branch block ,Linear discriminant analysis ,medicine.disease ,Hilbert–Huang transform ,Statistical classification ,medicine ,cardiovascular system ,Artificial intelligence ,cardiovascular diseases ,business ,Electrocardiography - Abstract
© 2018 IEEE.One of the main causes of sudden deaths is heart disease. Early detection and treatment of cardiac arrhythmias prevent the problem from reaching sudden deaths. The purpose of this study is to develop an arrhythmia detection algorithm based on Empirical Mode Decomposition (EMD). This algorithm consists of four steps: Preprocessing, Empirical Mode Decomposition, feature extraction and classification. Six arrhythmia types were used for differentiate normal and arrhythmic signals obtained from the MIT-BIH Arrhythmia database. These are normal (N), left bundle branch block (LBBB), right bundle branch block (RBBB), premature ventricular contraction (PVC), paced beat and atrial premature beats (APB). Three different classifiers were used to classify ECG signals. The method achieves better result with accuracy of 87% using linear discriminant analysis (LDA) classifier for detection of normal and arrhythmic signals.
- Published
- 2018
34. Synchronization Analysis of EEG Epilepsy by Visibility Graph Similarity
- Author
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Aydin Akan, Parvaneh Shams, and Ali Olamat
- Subjects
medicine.diagnostic_test ,business.industry ,Visibility graph ,Healthy subjects ,Pattern recognition ,Neurological disorder ,Electroencephalography ,medicine.disease ,Brain region ,Epilepsy ,Nonlinear model ,medicine ,Graph (abstract data type) ,Artificial intelligence ,business ,Mathematics - Abstract
Epilepsy is a neurological disorder of different types characterized by recurrent of seizures which affects people of all ages. This paper presents visibility graph similarity as a nonlinear model to analyze the epilepsy EEG data from different brain region of healthy and patient subjects with epilepsy seizures. All EEG segments are mapped into a corresponding graph to obtain the corresponding degree of sequence for each segment, and then the difference between these degrees is constructed as a similarity between two segments. The results showed that seizure activity presented strongest nonlinear dynamic response in the form of similarity level decreasing from healthy subjects to patients. Results of other sets were found to be in agreement with our results.
- Published
- 2018
- Full Text
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35. Emotion Recognition from EEG Signals by Using Empirical Mode Decomposition
- Author
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Mehmet Akif Ozdemir, Reza Sadighzadeh, Murside Degirmenci, and Aydin Akan
- Subjects
medicine.diagnostic_test ,business.industry ,Computer science ,Feature extraction ,Higher-order statistics ,Pattern recognition ,Electroencephalography ,Linear discriminant analysis ,Hilbert–Huang transform ,Support vector machine ,Naive Bayes classifier ,Frequency domain ,medicine ,Artificial intelligence ,business - Abstract
This study investigates improved properties of empirical mode decomposition (EMD) for emotion recognition by using electroencephalogram (EEG) signals. The emotion recognition from EEG signals is a difficult study by the reason of nonstationary behavior of the signals. These signals are affected from complicated neural activity of brain. To analyze EEG signals, advanced signal processing techniques are required. In our study, data are collected from one channeled BIOPAC lab system. EEG signals were obtained from visual evoked potentials of 13 female and 13 male volunteers for 12 pleasant and 12 unpleasant pictures. To analyze nonlinear and nonstationary characteristics of EEG signals, an EMD-based method is proposed for emotion recognition. Various time and frequency domain techniques such as power spectral density (PSD), and higher order statistics (HOS) are used to analyze the IMFs extracted by EMD. Support vector machine (SVM), Linear discriminant analysis (LDA), and Naive Bayes classifiers are utilized for the classification of features extracted from the IMFs, and their performances are compared.
- Published
- 2018
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36. Detection of Epileptic Seizures by the Analysis of EEG Signals Using Empirical Mode Decomposition
- Author
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Seyma Yol, Mehmet Akif Ozdemir, Aydin Akan, and Luis F. Chaparro
- Subjects
medicine.diagnostic_test ,Computer science ,business.industry ,Tsallis entropy ,Pattern recognition ,Electroencephalography ,Linear discriminant analysis ,medicine.disease ,Rényi entropy ,Epilepsy ,Naive Bayes classifier ,medicine ,Epileptic seizure ,Artificial intelligence ,medicine.symptom ,Entropy (energy dispersal) ,business - Abstract
The detection of epileptic seizure has a primary role in patient diagnosis with epilepsy. Epilepsy causes sudden and uncontrolled electrical discharges in brain cells. Recordings of the abnormal brain activities are time consuming and outcomes are very subjective, so automated detection systems are highly recommended. In this study, it is aimed to classify EEG signals for the detection of epileptic seizures using intrinsic mode functions (IMF) and feature extraction based on Empirical Mode Decomposition (EMD). These records have been acquired from the database of the Epileptology Department of Bonn University and consisting of 5 marker groups A, B, C, D, E in this study. These records taken from healthy individuals and patients are decomposed into IMFs by EMD method. Feature vectors have been extracted based on Tsallis Entropy, Renyi Entropy, Relative Entropy and Coherence methods. These features are then classified by K-Nearest Neighbors Classification (KNN), Linear Discriminant Analysis (LDA) and Naive Bayes Classification (NBC). Significant differences were determined between healthy and patient EEG data at the end of the study.
- Published
- 2018
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37. A Novel Approach for Computing EEG Phase Synchronization: Interchannels Phase Clustering Method
- Author
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Mehmet Akif Ozcoban and Aydin Akan
- Subjects
medicine.diagnostic_test ,Computer science ,business.industry ,Functional connectivity ,Phase (waves) ,Pattern recognition ,Electroencephalography ,Phase synchronization ,Signal ,Power (physics) ,Synchronization (computer science) ,medicine ,Artificial intelligence ,business ,Cluster analysis - Abstract
EEG is one of the most used devices in brain examinations, provides important information about many neurological diseases. The power of EEG signal's phase synchronization is a parameter that has been commonly used in brain investigations. The Interchannels Phase Clustering (ICPC) method that we propose in our study, is an improved version of the Intertrial Phase Clustering (ICPC) method. Global and regional phase synchronization studies can be done with ICPC method. The method is applied to the signals produced by an EEG simulator and the results are computed with high accuracy. This method can be applied to neuropsychiatric diseases and provide important information on functional connectivity and cognitive functions.
- Published
- 2018
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38. Synchronization Analysis of EEG Epilepsy by Visibility Network Graph and Cross-correlation
- Author
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Sibel Kocaaslan Atli, Ali Olamat, and Aydin Akan
- Subjects
Cross-correlation ,medicine.diagnostic_test ,Computer science ,business.industry ,Visibility (geometry) ,Pattern recognition ,Electroencephalography ,medicine.disease ,Correlation ,Epilepsy ,Synchronization (computer science) ,medicine ,Graph (abstract data type) ,Ictal ,Artificial intelligence ,business - Abstract
Epilepsy is a chronic neurological disorder affects people of all ages; this paper presents cross-correlation and state transfer network method to analyze synchronization between EEG data-channels from subjects with epilepsy seizures. The datasets are in two phases, preictal and ictal phase. All EEG segments are mapped into a corresponding state network graph to obtain the corresponding motifs and then the cross-correlation is applied to exhibit the synchronization changing during epilepsy seizures. The results showed that ictal phase presented high synchronization between channels, where low synchronization level is observed within preictal phase.
- Published
- 2018
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39. Analysis of reduced EEG channels based on emotional stimulus
- Author
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Adil Deniz Duru, Cansin Ozgor, Aydin Akan, Seray Senyer Ozgor, and Merve Dogruyol Basar
- Subjects
medicine.diagnostic_test ,Frequency band ,business.industry ,05 social sciences ,Spectral density ,Spectral density estimation ,Pattern recognition ,02 engineering and technology ,Electroencephalography ,Stimulus (physiology) ,050105 experimental psychology ,Radio spectrum ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,020201 artificial intelligence & image processing ,0501 psychology and cognitive sciences ,Analysis of variance ,Artificial intelligence ,business ,Mathematics ,Communication channel - Abstract
Electroencephalogram (EEG) signals are widely used to investigate the electrical activities in the brain an to get information for these activities. In this work, samples are selected from 3 type (Negative, Neutral, Positive) emotional pictures from ‘Nencki Affective Picture System’ and shown to subjects. EEG signals are collected according to 10–20 international electrode system standards. Collected signals are reduced to 3 type channels (Frontal, Parieto-Occipital, Central). Power Spectral Density (PSD) of the corresponding EEG signals are investigated and separated into EEG frequency bands (Delta, Theta, Alpha, Beta). Welch Spectral Estimation Method is applied into the acquired data and their PSDs are obtained after taking the expectation of their frequencies. Using PSDs, total power is calculated for each frequency band and channel. Then ANOVA analysis is performed and statistical differences are investigated. Our analyses show that statistically significant differences exist between each frequency band and 3 type of channels and among reduced channels themselves.
- Published
- 2018
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40. Classification of epileptic EEG data by using ensemble empirical mode decomposition
- Author
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Reza Sadighzadeh, Ozlem Karabiber Cura, Sibel Kocaaslan Atli, and Aydin Akan
- Subjects
medicine.diagnostic_test ,Computer science ,business.industry ,Feature extraction ,Mode (statistics) ,Pattern recognition ,02 engineering and technology ,Electroencephalography ,Linear discriminant analysis ,Hilbert–Huang transform ,03 medical and health sciences ,Naive Bayes classifier ,0302 clinical medicine ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Epileptic eeg ,020201 artificial intelligence & image processing ,Artificial intelligence ,business ,030217 neurology & neurosurgery - Abstract
In this study, our aim is to distinguish pre-seizure and seizure data from epileptic EEG signals using Ensemble Empirical Mode Decomposition (EEMD) and various classifiers. For this purpose, epileptic EEG data from 13 epileptic patients have been recorded using surface electrodes at Izmir Kâtip Celebi University School of Medicine, Neurology Department. First, EEG signals are divided into two parts as pre-seizure and seizure and decomposed into intrinsic mode functions (IMFs) using EEMD. Total power and higher order frequency moments are calculated as features from the first IMF by periodogram method. Extracted features are classified using Naive Bayes, K-nearest neighbors and Linear Discriminant Analysis methods. From the obtained classification results, it is seen that the Naive Bayes classifier outperforms the K-nearest neighbor and Linear Discriminant Analysis classification methods in pre-seizure and seizure data discrimination with maximum 100% and minimum 77% accuracy.
- Published
- 2018
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41. Analysis of frontal phase synchronization in OCD patients
- Author
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Oguz Tan, Aydin Akan, and Mehmet Akif Ozcoban
- Subjects
medicine.medical_specialty ,medicine.diagnostic_test ,0206 medical engineering ,Cognition ,02 engineering and technology ,Neurophysiology ,Electroencephalography ,Audiology ,Phase synchronization ,behavioral disciplines and activities ,020601 biomedical engineering ,Neuroimaging ,Obsessive compulsive ,mental disorders ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,020201 artificial intelligence & image processing ,Frontal region ,Psychology ,Clinical evaluation - Abstract
Obsessive Compulsive Disorder (OCD) is a common neuropsychiatrie disorder in the society. Functional disorders in the frontal side were detected in the clinical evaluation of OCD with brain imaging systems. In this study, the effects of the OCD on the frontal part are investigated with Intertrial Phase Clustering (ITPC) method. According to the analysis results, significant loss of synchronization was found in all EEG bands for 6 electrodes on the frontal region. In addition, that these results are consistent with the results obtained by imaging devices, it was also indicated that decreased synchronization cause functional dysconnectivity. Besides, when evaluated together with the results of studies investigating the relationship between EEG waves and cognitive functions, it also indicates that OCD may cause many cognitive impairments, such as loss of memory and attention.
- Published
- 2018
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42. Analysis of gastric myoelectrical activity from the electrogastrogram signals based on wavelet transform and line length feature
- Author
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Aydin Akan and Abdullah Al Kafee
- Subjects
Variance test ,Discrete wavelet transform ,Adult ,Male ,Wavelet Analysis ,Line length ,Signal ,03 medical and health sciences ,0302 clinical medicine ,Electrogastrogram ,medicine ,Humans ,Analysis of Variance ,medicine.diagnostic_test ,business.industry ,Mechanical Engineering ,Diabetic gastroparesis ,digestive, oral, and skin physiology ,Stomach ,Wavelet transform ,Signal Processing, Computer-Assisted ,General Medicine ,Electrophysiological Phenomena ,Feature (computer vision) ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,Female ,business ,Biomedical engineering ,Muscle Contraction - Abstract
Electrogastrogram is used for the abdominal surface measurement of the gastric electrical activity of the human stomach. The electrogastrogram technique has significant value as a clinical tool because careful electrogastrogram signal recordings and analyses play a major role in determining the propagation and coordination of gastric myoelectric abnormalities. The aim of this article is to evaluate electrogastrogram features calculated by line length features based on the discrete wavelet transform method to differentiate healthy control subjects from patients with functional dyspepsia and diabetic gastroparesis. For this analysis, the discrete wavelet transform method was used to extract electrogastrogram signal characteristics. Next, line length features were calculated for each sub-signal, which reflect the waveform dimensionality variations and represent a measure of sensitivity to differences in signal amplitude and frequency. The analysis was carried out using a statistical analysis of variance test. The results obtained from the line length analysis of the electrogastrogram signal prove that there are significant differences among the functional dyspepsia, diabetic gastroparesis, and control groups. The electrogastrogram signals of the control subjects had a significantly higher line length than those of the functional dyspepsia and diabetic gastroparesis patients. In conclusion, this article provides new methods with increased accuracy obtained from electrogastrogram signal analysis. The electrogastrography is an effective and non-stationary method to differentiate diabetic gastroparesis and functional dyspepsia patients from the control group. The proposed method can be considered a key test and an essential computer-aided diagnostic tool for detecting gastric myoelectric abnormalities in diabetic gastroparesis and functional dyspepsia patients.
- Published
- 2018
43. Electrogastrography in patients with diabetic gastroparesis
- Author
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Aydin Akan, Abdullah Al Kafee, and Sevim Eryigit
- Subjects
medicine.medical_specialty ,Gastric emptying ,medicine.diagnostic_test ,business.industry ,Stomach ,Diabetic gastroparesis ,Healthy subjects ,Dominant frequency ,medicine.disease ,Gastroenterology ,Endoscopy ,medicine.anatomical_structure ,Diabetes mellitus ,Internal medicine ,medicine ,In patient ,business - Abstract
Electrogastrography (EGG) is an experimental non-invasive method that reflects the myoelectrical activity of the diabetic gastroparesis (D-GP) and healthy subjects gastric system. In clinical world, endoscopy and delayed gastric emptying diagnosis test are using for understand the D-GP patient's condition which are invasive, quite expensive and uncomfortable. Therefore our aim is to evaluate the Electrogastrography (EGG) features to discriminate the healthy subjects from patients with D-GP in real clinic. Total 25 patients D-GP and twenty 25 healthy subjects (HS) were included in this study. The recordings EGG parameters dominant frequency (DF) were analyzed and compared. The results we obtained from analysis of EGG signals proved that pre-fed (p= 0.048) and post-fed (p= 0.003) DF values were statistically significant between the D-GP and HS groups. This study proved that it is possible to distinguish D-GP patients from healthy subject's with a high accuracy and a great success from the EGG signals recording correctly in real clinic.
- Published
- 2017
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44. Investigation of EEG relative power spectral changes in obsesive compulsive disorder patients
- Author
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Oguz Tan, Aydin Akan, and Mehmet Akif Ozcoban
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medicine.medical_specialty ,medicine.diagnostic_test ,Relative power ,Alpha (ethology) ,Audiology ,Electroencephalography ,Mental activity ,behavioral disciplines and activities ,humanities ,Alpha band ,Obsessive compulsive ,medicine ,Statistical analysis ,Frontal region ,Psychology - Abstract
Obsessive Compulsive Disorder (OCD) is a neuropsychiatrie disorder that usually negatively affects feelings and thoughts of adolescent adversely. Studies of OCD with imaging methods have found intense mental activity in the frontal region. In this study, relative power values are calculated for the channels representing the frontal regions. These values were compared with the data values of the data obtained from healthy volunteers. After statistical analysis, power values of OCD patients were found higher in the teta and alpha frequency regions than in the control group. These values found in the alpha band, which are known to be important for mental activities, show a good deal of previous work done with imaging methods.
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- 2017
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45. Lesion detection from the mammography image using the Vision Development Module
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Ozlem Karabiber Cura, Savas Sahin, and Aydin Akan
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medicine.diagnostic_test ,Lesion detection ,business.industry ,Computer science ,Radius ,Total error ,Image (mathematics) ,Histogram ,medicine ,Mammography ,Development (differential geometry) ,Computer vision ,Artificial intelligence ,business ,Histogram equalization - Abstract
In this study, it was aimed to detect lesion and their radius information from mammography images using the Vision Development Module. The study was performed using ten different images with uniformly distributed lesions from the mammography images found in the MIAS database. First, threshold was applied to the mammography images loaded into the Vision Development Module to make the lesions clear. Then morphological filtering, histogram equalization and shape detection functions were used consequently radius information was obtained by detecting lesions. As a result, the error value between the known radius values of the lesions and the radius values found using the module was calculated and the minimum error value was found to be 3% and the maximum error value was found to be 24%. The total error value in the determination of the radius of the lesion in all mammography images examined, was found to be 15%.
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- 2017
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46. State transfer network of time series based on visibility graph analysis for classifying and prediction of epilepsy seizures
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Parvaneh Shams, Aydin Akan, and Ali Olamat
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Multivariate statistics ,medicine.diagnostic_test ,business.industry ,Computer science ,Visibility graph ,Pattern recognition ,Electroencephalography ,medicine.disease ,Epilepsy ,Eeg data ,Visibility graph analysis ,medicine ,Artificial intelligence ,Time series ,business ,Network analysis - Abstract
Visibility graph analysis of time series became widely used as a time series analysis in the recent years. State transfer network is a network of mapping mono/multivariate time series into a network of local states based on visibility graph, it was used to study the evolutionary behavior of time series and in this study, we applied this principle to the detection of epileptic seizures. Two sets of EEG data were used; first set was obtained from subjects with the healthy brain and the second set obtained from an unhealthy part of the brain during existence of epileptic seizures. Results show a clear discrepancy between the two groups of data with a dominantly appearance of particular nodes in the networks of an epileptic group called hubs or motif, accordingly, the visibility graph network analysis based analysis can be considered as a prediction way of epilepsy seizures.
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- 2017
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47. Emotion elicitation analysis in multi-channel EEG signals using multivariate Empirical Mode Decomposition and Discrete Wavelet Transform
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Bulent Yilmaz, Aydin Akan, and Pinar Ozel
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Discrete wavelet transform ,medicine.diagnostic_test ,Computer science ,business.industry ,Pattern recognition ,State (functional analysis) ,Electroencephalography ,Hilbert–Huang transform ,DEAP ,Support vector machine ,symbols.namesake ,Wavelet ,Fourier transform ,medicine ,symbols ,Artificial intelligence ,business - Abstract
In recent years, wavelet-based, Fourier-based and Hilbert-based time-frequency methods attracted attention in emotion state classification studies in human machine interaction. In particular, the Hilbert-based Empirical Mode Decomposition and Wavelet-based Discrete Wavelet Transform have found applications in emotional state analysis. In this study, a model of emotional elicitation is proposed in which the classification is made by using the features of the wavelet coefficients obtained after applying the Discrete Wavelet Transform to IMFs achieved by using Multivariate Empirical Mode Decomposition. Accordingly, EEG data available in the DEAP database were classified as low / high for valence, activation, and dominance dimensions, and 4 different classifiers were used in the classification phase. The best ratios of valence, activation and dominance were obtained ideally 70.1%, 58.8%, 60.3% respectively.
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- 2017
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48. Analyses of changes in electrocardiogram signals during Hookah Smoking
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Aydin Akan, Umar Faruok Ibrahim, and Ali Olamat
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,RR interval ,Hookah Smoking ,medicine.disease ,Sudden cardiac death ,QRS complex ,Internal medicine ,Heart rate ,medicine ,Cardiology ,cardiovascular diseases ,Risk factor ,PR interval ,business ,Electrocardiography - Abstract
Hookah Smoking results to escalation in premature beats of the ventricles, which tend to be a leading risk factor that results to sudden cardiac death (SCA). Hookah smokers tend to be at high risk for cardiovascular diseases due to tobacco consumption from a hookah device. The primary objective of this research is to analyze immediate consequences of hookah smoking on ECG. A secondary aim is to compare changes that occur in ECG before and after hookah smoking. ECG changes powerfully predict future cardiovascular disorders (CVD) events. Twenty Male volunteers who are sound in health and are in the age bracket of 18–30 years were recruited for the study. The ECG of the subjects was recorded using a 3-lead electrocardiogram. From the lead to, PR interval, QRS (amplitude) and RR interval were recorded and heart rate was also determined, (P, Q, R and S are ECG signal's parts). Various changes observed in this study were results of persistent and terrible consequences of hookah smoking that may result into chronic CVD. These abnormalities could be identified with the help of a simple noninvasive tool by determining the wave amplitude and duration of ECG parameters.
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- 2017
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49. Emotion recognition classification in EEG signals using multivariate synchrosqueezing transform
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Bulent Yilmaz, Pinar Ozel, Aydin Akan, AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü, and Yilmaz, Bulent
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Multivariate statistics ,Data processing ,Signal processing ,medicine.diagnostic_test ,Computer science ,business.industry ,Short-time Fourier transform ,Wavelet transform ,Pattern recognition ,Electroencephalography ,Time–frequency analysis ,Support vector machine ,emotion recognition ,medicine ,EEG ,Artificial intelligence ,multivariate sychrosqueezing transform ,business - Abstract
Electrophysiological data processing can take place both in time and in frequency domains as well as in the joint time-frequency domain. Short Time Fourier Transform and Wavelet Transform are commonly used time-frequency analysis methods. The limitations of these methods initiated the use of methods such as synchrosqueezing and multivariate synchrosqueezing methods. In our proposed method 88.9%, 77.8%, 80.6% accuracy rates were obtained respectively for the valence, activation and dominance parameters using and multivariate synchrosqueezing methods and support vector machines(SVM) which yields better results than most of the other methods mentioned in the literature. IEEE Turkey Sect
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- 2017
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50. Analysis of EMG signals in the Quadratus Lumborum muscle of healthy subject with functional leg length discrepancy
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Sevim Eryigit, Aydin Akan, Abdullah Al Kafee, and Mustafa Selman Yildmm
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medicine.diagnostic_test ,business.industry ,Quadratus lumborum muscle ,Leg length ,Biomechanics ,Healthy subjects ,Electromyography ,Anatomy ,Iliac crest ,Prone position ,medicine.anatomical_structure ,medicine ,business ,Pelvis - Abstract
The purpose of this study was to analyze the electromyography (EMG) signals of the Quadratus Lumborum (QL) muscle activity on leg length discrepancy (LLD) and pelvic asymmetry. So we investigated whether pelvic asymmetry might cause injuries in lumbar spine and lower extremity. This was a randomized control experiment, total 50 (25 males and 25 females) datas were analyzed. All participants were right handed. Iliac crest levels were assessed by manually and LLD measurement was used with tape. EMG signals of the QL muscle were taken in the resting position without any activity intentionally in the prone position. Analysis of the data revealed that the QL muscles activity were higher at the pelvic elevation on the right side than on the left side. While there was a shortness in the lower extremity 27% of the cases on the right condition but it was statistically determined that 23% of the left side was short. At the same time, 100% of the cases in the lower extremity on the right side were found to be in the right iliac crest elevation position. Unilateral hyperactivity of the QL muscle leads to instability of the spine and pelvic muscles and causing pelvis asymmetry and functional LLD. As a result, unbalanced loading on the spine and lower extremities may result in injury.
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- 2017
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