Sürdürülebilir Kalkınma Amaçları
Yayınlar
- BildiriYalnız künye2025Tumor Classification via Subregion Combinations of Cortical L5PC6 Pyramidal Neurons
Ozcan, Zubeyir; Bozkir, Ilknur Kayikcioglu; Kayikcioglu, Temel
In this study, it was aimed to classify benign and malignant tumor samples by utilizing different subregions of a cortical L5PC6 pyramidal neuron. A spike-based learning method was applied to a real dataset, and a decision mechanism based on action potential generation was established by training a separate neuron for each class. During the training process, various types of synaptic connections and spike encoding schemes were evaluated and intensity coding yielded the highest performance for the pyramidal neuron. Regional analyses revealed that the basilar region particularly stood out in terms of classification success. The results demonstrate that the morphological and biophysical diversity of pyramidal neurons provides a significant advantage in classification tasks.
- BildiriYalnız künye2023Shape of Masses in Contrast Mammography Images and First Order Statistical Features Classification Based on
Kobya, Mehmet Emin; Ture, Hayati; Dogan, Ramazan Ozgur; Kayikcioglu, Temel; Teymur, Aykut; Kul, Sibel
Mammography is a valuable tool in the diagnosis and staging of primary breast cancer. Contrast-enhanced mammography (CEM) combines an iodinated contrast agent with traditional mammography to increase diagnostic accuracy, especially in women with more dense parenchymal background patterns. In this study, a Decision Support System (DSS) is proposed that classifies masses using radiomic features obtained from masks of benign and malignant masses in images obtained with the CEM technique. An open-access database containing 2006 CEM images was used in this study. Radiomic features obtained from these images were used to identify differences between benign and malignant masses. The DSS uses these features to classify masses using a decision tree algorithm. This study highlights the importance of the use of iodinated contrast agents to improve diagnostic accuracy in women with more dense parenchymal background patterns. Additionally, it emphasizes the potential benefits of a DSS, in combination with radiomic features, in the diagnosis and staging of breast cancer. In conclusion, this study demonstrates that the use of radiomic features in mammography images obtained with the CEM technique is an effective way to classify benign and malignant masses.The use of this technology could be an important tool in the early diagnosis and accurate classification of breast cancer.
- BildiriYalnız künye2023An Efficient 1D Autoencoder-Based Approach for R-Peaks Detection in Electrocardiogram Signals
Dogan, Ramazan Ozgur; Dogan, Hulya; Kayikcioglu, Temel
Electrocardiogram (ECG) signal which is composition of multiple segments such as P-wave, QRS complex and T-wave plays a crucial role in evaluating human heart cardiac diagnosis. For an analysis of cardiac diagnosis, it is required that clinicians scan the ECG signal for R-peaks (the highest peak of the QRS complex) detection, which relies on their expertise and takes enormous time. In order to provide more realistic treatment of cardiovascular diseases in the ECG signal with noises and different characteristics, computer-based R-peaks detection approaches have been actively developed in the research article for many years and generally compose of two major operations; preprocessing and decision. Contrary to previous approaches which require high computational costs and complexity, appropriate initial parameters, a novel CNN based approach is presented for R-peaks detection in this paper. Both qualitative and quantitative analysis are performed in the real ECG signal taken from typical MIT-BIH arrhythmia database. In order to validate the success of the recommended approach, total 18 different R-peaks detection approaches reported in the literature are compared by utilizing performance evaluation metrics. Average values of sensitivity, positive predictivity, error rate, accuracy and f-score are computed as 99,96%, 99,95%, 0,09%, 99,90% and 99,95% respectively, which are the best values among well-established studies for R-peaks detection. It is demonstrated with qualitative and quantitative results that better performance is achieved by our suggested approach.
- MakaleAçık Erişim2021Eeg sinyallerini kullanarak 2B ve 3B hibrit bir videonun ayrıntılı kanal/lob analizi
Melek, Negin; Melek, Mesut; Kayikcioglu, Temel
İnsan gözünün yapısına göre 2 Boyutlu (2B) ve 3B parçalardan oluşan video analizinde ani geçiş ve sabit durumların değerlendirilmesi önemlidir. Bu çalışmada, insan beyin sinyallerinin güç spektrum yoğunluğu (GSY), 2B ve 3B hibrit video izleme sonucunda analiz için dikkate alınmıştır. İnsanların yorulunca derinlik algısının kaybettiğini daha önceki çalışmalarımızda iddia etmiştik. Bu çalışmada, rastgele 2B ve 3B parçalardan oluşan, tek akışlı bir anaglif video sağlanmıştır. 2B ve 3B hibrit video çalışmasında, beyin sinyal analizinde kısa zamanlı Fourier dönüşümüne (KZFD) dayalı GSY ve spektrogram adı verilen görsel temsil kullanılmıştır. Tüm EEG frekans bantları test edildikten sonra, spektrogram çizelgesindeki 2B ve 3B parçaların karşılaştırılmasında GSY farkı dikkate alınarak, delta bandı baskın bant olarak seçilmiştir. Bu banttan çıkarılan öznitelikler iki popüler sınıflandırıcı tarafından sınıflandırılmıştır. Bunlar destek vektör makinesi (DVM) ve doğrusal ayırma analizi (DAA) algoritmalarıdır. Sonuç olarak, frontal ve temporal loblar, 2B ve 3B geçişlerin sınıflandırılmasında diğer loblara göre daha iyi sonuçlar göstermektedir. Öznitelik çıkarma yöntemi olarak kullanılan istatistiksel fonksiyonlar ve Hjorth parametreleri sonucunda DVM ve DAA algoritmaları için sınıflandırma başarısı sırasıyla %68 ve %79 olarak hesaplanmıştır.
- BildiriYalnız künye2021BroomyCell: An Introductory Educational Software for Neuroscience
Ozcan, Zubeyir; Yildirim, Omer; Kayikcioglu, Temel
Nerve cells are the basic building blocks of the nervous system. Therefore, the first step in neuroscience education is the introduction of nerve cells. However, both the complexity of nerve cells and the difficulty of their experimental examination make it difficult to test nerve cells practically. Therefore, simulation of nerve cells is found to be significantly effective. The difficulty of examining this type of cells experimentally shows its effect on neuroscience education. This brings to the fore the necessity of virtual laboratory environments designed for use in education. In this study, BroomyCell, which is designed by us as an introductory educational software in neuroscience education, was introduced. With this desktop application, it is aimed that potential neuroscientists learn their fields experimentally and without the need for a physical laboratory.
- MakaleYalnız künye2021Polydimethylsiloxane-based capacitive motion sensor and its read-out circuit
Yildirim, Omer; Bozyel, Ibrahim; Saka, Kubra; Kayikcioglu, Temel; Gokcen, Dincer
A capacitive motion sensor that can detect human walking and motions up to a certain distance was designed using polydimethylsiloxane (PDMS) as the primary sensor material. A read-out circuit was designed to detect capacitive coupling with the sensor material caused by the motion in the surrounding. The read-out circuit consists of sensing, filtering, and amplifying stages. A high-pass filter was used to avoid DC components, and to eliminate adverse impacts of 50Hz noise in the sensing signal, a sixth-order low-pass filter consisting of active Sallen–Key and passive RC filters was utilized. The signals obtained from the complete read-out circuit revealed that the sensor system could accurately detect human movements up to 2 m away. Also, different signal patterns were obtained from the output of the sensor system for various human motions.
- MakaleYalnız künye2021Brain-computer interface systems for smart homes-a review study
Maleki, Masoud; Manshouri, Negin; Kayikcioglu, Temel
Brain-computer Interface (BCI) systems, usually using signals taken from users' brain through electroencephalography (EEG), control various devices around and provide the user's com-mand by interacting. Improving the quality of life of people with disabilities is the main goal of BCI systems. The importance of BCI-based smart home systems is further increasing as a smart home system directly affects the life of a disabled individual. On the other hand, few BCI systems can be run directly using smart home systems. The importance of the BCI-based smart home and the few existing systems require more work in this vital field. In addition, no reviews have described BCI systems in a smart home. In this study, we reviewed all the papers on BCI-based smart home systems published in the last 6 years. These studies investigated and evaluated BCI systems from nine different perspectives. In addition, all studies were examined in terms of signal processing methods. Finally, the problems and challenges of these systems were discussed and new solutions were pro-posed.
- MakaleAçık Erişim2021A Two-Phase Approach using Mask R-CNN and 3D U-Net for High-Accuracy Automatic Segmentation of Pancreas in CT Imaging
Dogan, Ramazan Ozgur; Dogan, Hulya; Bayrak, Coskun; Kayikcioglu, Temel
Background and objective: The size, shape, and position of the pancreas are affected by the patient characteristics such as age, sex, adiposity. Owing to more complex anatomical structures (size, shape, and position) of the pancreas, specialists have some difficulties in the analysis of pancreatic diseases (diabetes, pancreatic cancer, pancreatitis). Therefore, the treatment of the disease requires enormous time and depends on the experience of specialists. In order to decrease the rate of pancreatic disease deaths and to assist the specialist in the analysis of pancreatic diseases, automatic pancreas segmentation techniques have been actively developed in the research article for many years. Methods: Although the rapid growth of deep learning and proving satisfactory performance in many medical image processing and computer vision applications, the maximum Dice Similarity Coefficients (DSC) value of these techniques related to automatic pancreas segmentation is only around 85% due to complex structure of the pancreas and other factors. Contrary to previous techniques which are required significantly higher computational power and memory, this paper suggests a novel two-phase approach for high-accuracy automatic pancreas segmentation in computed tomography (CT) imaging. The proposed approach consists of two phases; (1) Pancreas Localization, where the rough pancreas position is detected on the 2D CT slice by adopting Mask R-CNN model, (2) Pancreas Segmentation, where the segmented pancreas region is produced by refining the candidate pancreas region with 3D U-Net on the 2D sub-CT slices generated in the first phase. Both qualitative and quantitative assessments of the proposed approach are performed on the NIH data set. Results: In order to evaluate the achievement of the recommended approach, a total of 16 different automatic pancreas segmentation techniques reported in the literature are compared by utilizing performance assessment procedures which are Dice Similarity Coefficient (DSC), Jaccard Index (JI), Precision (PRE), Recall (REC), Pixel Accuracy (ACC), Specificity (SPE), Receiver Operating Characteristics (ROC) and Area under ROC curve (AUC). The average values of DSC, JI, REC and ACC are computed as 86.15%, 75.93%, 86.27%, 86.27% and 99.95% respectively, which are the best values among well-established studies for automatic pancreas segmentation. Conclusion: It is demonstrated with qualitative and quantitative results that our suggested two-phase approach creates more favorable results than other existing approaches.
- MakaleYayıncıda açık erişim2021An automatic EEG-based sleep staging system with introducing NAoSP and NAoGP as new metrics for sleep staging systems
Melek, Mesut; Manshouri, Negin; Kayikcioglu, Temel
Different biological signals are recorded in sleep labs during sleep for the diagnosis and treatment of human sleep problems. Classification of sleep stages with electroencephalography (EEG) is preferred to other biological signals due to its advantages such as providing clinical information, cost-effectiveness, comfort, and ease of use. The evaluation of EEG signals taken during sleep by clinicians is a tiring, time-consuming, and error-prone method. Therefore, it is clinically mandatory to determine sleep stages by using software-supported systems. Like all classification problems, the accuracy rate is used to compare the performance of studies in this domain, but this metric can be accurate when the number of observations is equal in classes. However, since there is not an equal number of observations in sleep stages, this metric is insufficient in the evaluation of such systems. For this purpose, in recent years, Cohen’s kappa coefficient and even the sensitivity of NREM1 have been used for comparing the performance of these systems. Still, none of them examine the system from all dimensions. Therefore, in this study, two new metrics based on the polygon area metric, called the normalized area of sensitivity polygon and normalized area of the general polygon, are proposed for the performance evaluation of sleep staging systems. In addition, a new sleep staging system is introduced using the applications offered by the MATLAB program. The existing systems discussed in the literature were examined with the proposed metrics, and the best systems were compared with the proposed sleep staging system. According to the results, the proposed system excels in comparison with the most advanced machine learning methods. The single-channel method introduced based on the proposed metrics can be used for robust and reliable sleep stage classification from all dimensions required for real-time applications.
- MakaleAçık Erişim2020EEG Kullanarak 2D&3D Video Geçişinin Tespitinde Frontal ve Temporal Lobların Etkinliği
Melek, Negin; Melek, Mesut; Kayikcioglu, Temel
İnsan gözünün üç boyutlu (3B) yapısı nedeniyle, bu araştırmada 3B teknolojisi kullanılmıştır. Binoküler görmenin yorgunluk esnasında boyut kaybedeceğini iddia ederek 2B ve 3B’ye geçiş analizi önemlidir. Böylece rastgele 2B ve 3B parçalardan oluşan tek akışlı bir video dokuz gönüllü tarafından izlenilmiştir. Gönüllülerin beyin sinyallerinin dinamik davranışı ve güç spektral yoğunluğu (GSY), kapsamlı bir nicel analiz için dikkate alınmıştır. Baskın EEG bantları ve zaman aralıkları, kısa zamanlı Fourier dönüşümüne (KZFD) dayalı güç farklılıklarını analiz ederek 2B’den 3B’ye (2B_3B) ve 3B’den 2B’ye (3B_2B) geçişlerde seçilmiştir. Bu bilgiler dikkate alınarak, etkili özellik çıkarımı ve sınıflandırma teknikleri uygulanarak, gönüllülerin beyin loblarını temsil eden kanalların davranış kalıpları analiz edilmiştir. Öznitelik çıkarma yöntemleri olarak Hjorth parametreleri ve istatistiksel yöntemler kullanılmıştır. 2B_3B ve 3B_2B geçişlerini sınıflandırmak için en yakın komşular (e-YK) ve doğrusal diskriminant analiz (DDA) algoritmaları uygulanmıştır. Sonuçlar, 2B_3B ve 3B_2B geçişlerinin kapsamlı sınıflandırma analizi sayesinde beyin korteksinin aktivite gücünün değişiminin temsil edilebileceğini ortaya koymuştur. Bu geçişleri temsil eden kanallar arasındaki temporal ve frontal lobların baskınlığı göz ardı edilemez.
- MakaleAçık Erişim2020Low-cost brain-computer interface using the emotiv epoc headset based on rotating vanes
Melek, Mesut; Manshouri, Negin; Kayikcioglu, Temel
In the brain-computer interface system (BCI), electroencephalography (EEG) signals are converted into digital signals and analyzed, allowing direct communication between humans and the electronic devices around them. The convenience of the user and the speed of communication with the surrounding devices are the most important challenges of BCI systems. The Emotiv Epoc headset minimizes the discomfort of the user thanks to its wet electrodes and easy handling. In the continuation of our previous works, in this paper, we developed our BCI system based on the gaze at the rotating vanes using the inexpensive Emotiv Epoc headset. In addition to user comfort, our design has an acceptable mean accuracy rate (ACC) and mean information transfer rate (ITR) compared to similar systems.
- MakaleYalnız künye2020An EEG-based stereoscopic research of the PSD differences in pre and post 2D&3D movies watching
Manshouri, Negin; Maleki, Masoud; Kayikcioglu, Temel
Despite knowing the reality of three-dimensional (3D) technology in the form of eye fatigue, this technology continues to be retained by people (especially the young community). To check the influences of the human brain's power spectrum density (PSD) pre and post a 2D and 3D movie watching, a five-member test group was arranged. In this study, electroencephalogram (EEG) was used as a neuroimaging method. EEG recordings of five individuals were taken both before and after watching 2D and 3D movies. The main framework of this study was to analyze the effects of power spectrum density (PSD) of the human brain by testing all EEG frequency bands before and after 2D and 3D movie watching, also to determine effective brain lobes, and consequently, EEG channels. After 2D/3D EEG recording, this record was divided into three stages for analysis. These stages consisted of Relax, Watching, and Rest. This benchmarking analysis included I) before and after watching the 2D movie (R2b and R2a), II) before and after watching the 3D movie (R3b and R3a), and III) after watching the 2D/3D movie (R2a and R3a). In the Relax and Rest stages, the 2D/3D EEG power differences in all channels of brain regions for the five EEG bands, including delta (δ), theta (θ), alpha (α), beta (β), and gamma (γ), were analyzed and compared. The PSD based on short-time Fourier transform (STFT) was used to select the dominant bands in this study. Feature extraction was performed on the preprocessed EEG signals using STFT and discrete wavelet transform (DWT). In the 2D analysis, δ, θ, α, and β acted as dominant bands, in 3D, δ, θ, and α were dominant bands, and in 2D/3D, δ and α were selected as meaningful and dominant bands. Partial least-squares regression (PLSR) and support vector machine (SVM) classification algorithms were considered in order to classify the obtained R2a and R3a EEG signals. After the dominant band selection, the correct choice of effective channel combinations in these bands resulted in the percentage of high success of classifiers for Stage III. Taking into account the optimum number of channels, the best percentage of classification accuracy for the average of PLSR and SVM classification results by considering the best channels of SVM and DWT feature extraction method is 91.83% and 80.73% respectively.
- BildiriYalnız künye2018Power spectrum analysis of EEG for watching 2D & 3D videos and resting state
Manshouri, Negin; Maleki, Masoud; Kayikcioglu, Temel
Analysis of the brain waves has become useful over than 80 years. Along with the medical application, the brain signal is also used for other research works in the last fifteen years. In this study, by considering the depth factor in the image of a video, the effects of it are checked on EEG. A video is displayed in two-dimensional (2D) and three-dimensional (3D) format to the subjects. After recording the EEG signals in video watching, the resting state was recorded. Three states are considered for a better understanding of these effects on EEG. These states involve 2D&3D, 2D&resting and 3D&resting. Frequency analysis of the signals is evaluated by two methods. These methods are Fast Fourier Transform (FFT) and Welch method.
- BildiriYalnız künye2018Fast and accurate classifier-based brain-computer interface system using single channel EEG data
Maleki, Masoud; Manshouri, Negin; Kayikcioglu, Temel
In brain-computer interface system (BCIs), direct communication between humans and computers is performed by analyzing neural signals and transforming them into digital signals. In the continuation of our previous works, in this paper, we advanced the proposed BCI system that was based on the gaze on rotating vanes. The speed of communication and convenience of the user are very important factors in BCI systems. Therefore, in this paper, for the convenience of the user, a single EEG channel was used. Also, for to increase the speed of the system, we tried to the classification of 0.5 sec epochs with a partial least squares regression (PLSR) as a fast classifier. In addition, we computed the information transfer rate (ITR) that has proved our proposed BCI system is fast and accurate. This system could be used in real-time implementations due to having high classification rate, speed and convenience of the user.