Stroke is brain cell death because of either lack of blood flow (ischemic) or bleeding (hemorrhagic) that prevents the brain from functioning properly in both conditions. Ischemic stroke is a common type of stroke caused by a blockage in the cerebrovascular system that prevents blood from flowing to brain regions and directly blocks blood vessels. Computed tomography (CT) scanning is frequently used in the evaluation of stroke, and rapid and accurate diagnosis of ischemic stroke with CT images is critical for determining the appropriate treatment. The manual diagnosis of ischemic stroke can be error-prone due to several factors, such as the busy schedules of specialists and the large number of patients admitted to healthcare facilities. Therefore, in this paper, a deep learning-based interface was developed to automatically diagnose the ischemic stroke through segmentation on CT images leading to a reduction on the diagnosis time and workload of specialists. Convolutional Neural Networks (CNNs) allow automatic feature extraction in ischemic stroke segmentation, utilized to mark the disease regions from CT images. CNN-based architectures, such as U-Net, U-Net VGG16, U-Net VGG19, Attention U-Net, and ResU-Net, were used to benchmark the ischemic stroke disease segmentation. To further improve the segmentation performance, ResU-Net was modified, adding a dilation convolution layer after the last layer of the architecture. In addition, data augmentation was performed to increase the number of images in the dataset, including the ground truths for the ischemic stroke disease region. Based on the experimental results, our modified ResU-Net with a dilation convolution provides the highest performance for ischemic stroke segmentation in dice similarity coefficient (DSC) and intersection over union (IoU) with 98.45 % and 96.95 %, respectively. The experimental results show that our modified ResU-Net outperforms the state-of-the-art approaches for ischemic stroke disease segmentation. Moreover, the modified architecture has been deployed into a new desktop application called BrainSeg, which can support specialists during the diagnosis of the disease by segmenting ischemic stroke.

The conventional approach for identifying ground glass opacities (GGO) in medical imaging is to use a convolutional neural network (CNN), a subset of artificial intelligence, which provides promising performance in COVID-19 detection. However, CNN is still limited in capturing structured relationships of GGO as the texture and shape of the GGO can be confused with other structures in the image. In this paper, a novel framework called DeepChestNet is proposed that leverages structured relationships by jointly performing segmentation and classification on the lung, pulmonary lobe, and GGO, leading to enhanced detection of COVID-19 with findings. The performance of Deep-ChestNet in terms of dice similarity coefficient is 99.35%, 99.73%, and 97.89% for the lung, pulmonary lobe, and GGO segmentation, respectively. The experimental investigations on DeepChestNet-Lung, DeepChestNet-Lobe and Deep-ChestNet-COVID datasets, and comparison with several state-of-the-art approaches reveal the great potential of DeepChestNet for diagnosis of COVID-19 disease.

In this study, the Deep Deterministic Policy Gradient (DDPG) algorithm, which consists of a combination of artificial neural networks and reinforcement learning, was applied to the Vertical Takeoff and Landing (VTOL) system model in order to control the pitch angle. This algorithm was selected because conventional control algorithms such as Proportional-Integral-Derivative (PID) controllers which cannot always generate a suitable control signal eliminating the disturbance and unwanted environment effects on the considered system. In order to control the system, training was carried out for a sinusoidal reference in the mathematical model of the VTOL system in the Simulink environment, through the DDPG algorithm with continuous action space from deep reinforcement learning methods that can produce control action values that take the structure that can maximize the reward according to a determined reward function for the purpose of control and the generalization ability of artificial neural networks. For sinusoidal reference and a constant reference, tracking error performances obtained for the pitch angle, which is the output for the specified VTOL system, were compared with the conventional PID controller performance in terms of mean square error, integral square error, integral absolute error, percentage overshoot and settling time. The obtained results are presented via the simulations studies.

The coronavirus disease (COVID-19) has taken the entire world under its influence, causing a worldwide health crisis. The most concerning complication is acute hypoxemic respiratory failure that results in fatal consequences. To alleviate the effect of COVID-19, the infected region should be analyzed before the treatment. Thus, chest computed tomography (CT) is a popular method to determine the severity level of COVID-19. Besides, the number of lobe regions containing COVID-19 on CT images helps radiologists to diagnose the findings, such as bilateral, multifocal, and multilobar. Lobe regions can be distinguished manually by radiologists, but this may result in misdiagnosis due to human intervention. Therefore, in this study, a new tool has been developed that can automatically extract lobe regions using artificial intelligence-based instance-aware semantic lobe segmentation. Convolution neural networks (CNNs) offer automatic feature extraction in the instance-aware semantic lobe segmentation task that extracts the lobe regions on CT images. In this paper, CNN-based architectures, including DeepLabV3+ with VGG-16, VGG-19, and ResNet-50, were utilized to create a benchmark for the instance-aware semantic lobe segmentation task. For further improvement in segmentation results, images were preprocessed to detect the lung region prior to lobe segmentation. In the experimental evaluations, a large-scale dataset including 9036 images with pixel-level annotations for lung and lobe regions, has been created. DeepLabV3+ with ResNet-50 showed the highest performance in terms of dice similarity coefficient (DSC) and intersection over union (IOU) for lobe segmentation at 99.59 % and 99.19 %, respectively. The experiments demonstrated that our approach outperformed several state-of-the-art methods for the instance-aware semantic lobe segmentation task. Furthermore, a new desktop application called LobeChestApp was developed for the segmentation of lobe regions on chest CT images.