Katerina D. Tzimourta

Dr. Katerina D. Tzimourta

University of Western Macedonia, Kozáni, Dytikí Makedonía, Greece
orcid
Postdoctoral Researcher | University of Western Macedonia

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
27 May 2023 in Data
Verified
Journal Article
Open access
PDF file
AMAndreas Miltiadous
Andreas Miltiadous
Katerina D. TzimourtaKaterina D. Tzimourta
Katerina D. Tzimourta
Theodora AfrantouTheodora Afrantou
Theodora Afrantou
Panagiotis IoannidisPanagiotis Ioannidis
Panagiotis Ioannidis
NGNikolaos Grigoriadis
Nikolaos Grigoriadis
Alexandros T TzallasAlexandros T Tzallas
Alexandros T Tzallas
Recently, there has been a growing research interest in utilizing the electroencephalogram (EEG) as a non-invasive diagnostic tool for neurodegenerative diseases. This article provides a detailed description of a resting-state EEG dataset of individuals with Alzheimer’s disease and frontotemporal dementia, and healthy controls. The dataset was collected using a clinical EEG system with 19 scalp electrodes while participants were in a resting state with their eyes closed. The data collection process included rigorous quality control measures to ensure data accuracy and consistency. The dataset contains recordings of 36 Alzheimer’s patients, 23 frontotemporal dementia patients, and 29 healthy age-matched subjects. For each subject, the Mini-Mental State Examination score is reported. A monopolar montage was used to collect the signals. A raw and preprocessed EEG is included in the standard BIDS format. For the preprocessed signals, established methods such as artifact subspace reconstruction and an independent component analysis have been employed for denoising. The dataset has significant reuse potential since Alzheimer’s EEG Machine Learning studies are increasing in popularity and there is a lack of publicly available EEG datasets. The resting-state EEG data can be used to explore alterations in brain activity and connectivity in these conditions, and to develop new diagnostic and treatment approaches. Additionally, the dataset can be used to compare EEG characteristics between different types of dementia, which could provide insights into the underlying mechanisms of these conditions.

12 July 2023 in IEEE Access
Verified
Journal Article
Open access
AMAndreas Miltiadous
Andreas Miltiadous
EGEmmanouil Gionanidis
Emmanouil Gionanidis
Katerina D. TzimourtaKaterina D. Tzimourta
Katerina D. Tzimourta
Nikolaos GiannakeasNikolaos Giannakeas
Nikolaos Giannakeas
Alexandros T TzallasAlexandros T Tzallas
Alexandros T Tzallas
Objective: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that affects a significant percentage of the elderly. EEG has emerged as a promising tool for the timely diagnosis and classification of AD or other dementia types. This paper proposes a novel approach to AD EEG classification using a Dual-Input Convolution Encoder Network (DICE-net). Approach: Recordings of 36 AD, 23 Frontotemporal dementia (FTD), and 29 age-matched healthy individuals (CN) were used. After denoising, Band power and Coherence features were extracted and fed to DICE-net, which consists of Convolution, Transformer Encoder, and Feed-Forward layers. Main results: Our results show that DICE-net achieved an accuracy of 83.28% in the AD-CN problem using Leave-One-Subject-Out validation, outperforming several baseline models, and achieving good generalization performance. Significance: Our findings suggest that a convolution transformer network can effectively capture the complex features of EEG signals for the classification of AD patients versus control subjects and may be expanded to other types of dementia, such as FTD. This approach could improve the accuracy of early diagnosis and lead to the development of more effective interventions for AD.

9 August 2021 in Diagnostics
Verified
Journal Article
Open access
PDF file
AMAndreas Miltiadous
Andreas Miltiadous
Katerina D. TzimourtaKaterina D. Tzimourta
Katerina D. Tzimourta
Nikolaos GiannakeasNikolaos Giannakeas
Nikolaos Giannakeas
Markos G. TsipourasMarkos G. Tsipouras
Markos G. Tsipouras
Theodora AfrantouTheodora Afrantou
Theodora Afrantou
Alexandros T TzallasAlexandros T Tzallas
Alexandros T Tzallas
Dementia is the clinical syndrome characterized by progressive loss of cognitive and emotional abilities to a degree severe enough to interfere with daily functioning. Alzheimer’s disease (AD) is the most common neurogenerative disorder, making up 50–70% of total dementia cases. Another dementia type is frontotemporal dementia (FTD), which is associated with circumscribed degeneration of the prefrontal and anterior temporal cortex and mainly affects personality and social skills. With the rapid advancement in electroencephalogram (EEG) sensors, the EEG has become a suitable, accurate, and highly sensitive biomarker for the identification of neuronal and cognitive dynamics in most cases of dementia, such as AD and FTD, through EEG signal analysis and processing techniques. In this study, six supervised machine-learning techniques were compared on categorizing processed EEG signals of AD and FTD cases, to provide an insight for future methods on early dementia diagnosis. K-fold cross validation and leave-one-patient-out cross validation were also compared as validation methods to evaluate their performance for this classification problem. The proposed methodology accuracy scores were 78.5% for AD detection with decision trees and 86.3% for FTD detection with random forests.

18 September 2018 in Health and Technology
Verified
Journal Article
Closed access
PDF file
Katerina D. TzimourtaKaterina D. Tzimourta
Katerina D. Tzimourta
Alexandros T TzallasAlexandros T Tzallas
Alexandros T Tzallas
Nikolaos GiannakeasNikolaos Giannakeas
Nikolaos Giannakeas
LALoukas G. Astrakas
Loukas G. Astrakas
DTDimitrios G. Tsalikakis
Dimitrios G. Tsalikakis
Markos G. TsipourasMarkos G. Tsipouras
Markos G. Tsipouras

14 April 2019 in Brain Sciences
Verified
Journal Article
Open access
PDF file
Katerina D. TzimourtaKaterina D. Tzimourta
Katerina D. Tzimourta
Nikolaos GiannakeasNikolaos Giannakeas
Nikolaos Giannakeas
Alexandros T TzallasAlexandros T Tzallas
Alexandros T Tzallas
LALoukas Astrakas
Loukas Astrakas
Theodora AfrantouTheodora Afrantou
Theodora Afrantou
Markos G. TsipourasMarkos G. Tsipouras
Markos G. Tsipouras
Alzheimer’s Disease (AD) is a neurogenerative disorder and the most common type of dementia with a rapidly increasing world prevalence. In this paper, the ability of several statistical and spectral features to detect AD from electroencephalographic (EEG) recordings is evaluated. For this purpose, clinical EEG recordings from 14 patients with AD (8 with mild AD and 6 with moderate AD) and 10 healthy, age-matched individuals are analyzed. The EEG signals are initially segmented in nonoverlapping epochs of different lengths ranging from 5 s to 12 s. Then, a group of statistical and spectral features calculated for each EEG rhythm (δ, θ, α, β, and γ) are extracted, forming the feature vector that trained and tested a Random Forests classifier. Six classification problems are addressed, including the discrimination from whole-brain dynamics and separately from specific brain regions in order to highlight any alterations of the cortical regions. The results indicated a high accuracy ranging from 88.79% to 96.78% for whole-brain classification. Also, the classification accuracy was higher at the posterior and central regions than at the frontal area and the right side of temporal lobe for all classification problems.

27 March 2021 in Sensors
Verified
Journal Article
Open access
PDF file
Evangelos AntoniouEvangelos Antoniou
Evangelos Antoniou
PBPavlos Bozios
Pavlos Bozios
Vasileios ChristouVasileios Christou
Vasileios Christou
Katerina D. TzimourtaKaterina D. Tzimourta
Katerina D. Tzimourta
Konstantinos KalafatakisKonstantinos Kalafatakis
Konstantinos Kalafatakis
Alexandros T TzallasAlexandros T Tzallas
Alexandros T Tzallas
Discrimination of eye movements and visual states is a flourishing field of research and there is an urgent need for non-manual EEG-based wheelchair control and navigation systems. This paper presents a novel system that utilizes a brain–computer interface (BCI) to capture electroencephalographic (EEG) signals from human subjects while eye movement and subsequently classify them into six categories by applying a random forests (RF) classification algorithm. RF is an ensemble learning method that constructs a series of decision trees where each tree gives a class prediction, and the class with the highest number of class predictions becomes the model’s prediction. The categories of the proposed random forests brain–computer interface (RF-BCI) are defined according to the position of the subject’s eyes: open, closed, left, right, up, and down. The purpose of RF-BCI is to be utilized as an EEG-based control system for driving an electromechanical wheelchair (rehabilitation device). The proposed approach has been tested using a dataset containing 219 records taken from 10 different patients. The BCI implemented the EPOC Flex head cap system, which includes 32 saline felt sensors for capturing the subjects’ EEG signals. Each sensor caught four different brain waves (delta, theta, alpha, and beta) per second. Then, these signals were split in 4-second windows resulting in 512 samples per record and the band energy was extracted for each EEG rhythm. The proposed system was compared with naïve Bayes, Bayes Network, k-nearest neighbors (K-NN), multilayer perceptron (MLP), support vector machine (SVM), J48-C4.5 decision tree, and Bagging classification algorithms. The experimental results showed that the RF algorithm outperformed compared to the other approaches and high levels of accuracy (85.39%) for a 6-class classification are obtained. This method exploits high spatial information acquired from the Emotiv EPOC Flex wearable EEG recording device and examines successfully the potential of this device to be used for BCI wheelchair technology.