Publications by authors named "Kakkos I"

Background/objectives: Spasticity commonly occurs in individuals after experiencing a stroke, impairing their hand function and limiting activities of daily living (ADLs). In this paper, we introduce an exoskeletal aid, combined with a set of augmented reality (AR) games consisting of the Rehabotics rehabilitation solution, designed for individuals with upper limb spasticity following stroke.

Methods: Our study, involving 60 post-stroke patients (mean ± SD age: 70.

View Article and Find Full Text PDF

Sports injuries pose significant challenges in athlete welfare and team dynamics, particularly in high-intensity sports like soccer. This study used machine learning algorithms to assess non-contact injury risk in professional male soccer players from physiological and mechanical load variables. Twenty-five professional male soccer players with a first-time, non-contact muscle injury were included in this study.

View Article and Find Full Text PDF

Mental fatigue during driving poses significant risks to road safety, necessitating accurate assessment methods to mitigate potential hazards. This study explores the impact of individual variability in brain networks on driving fatigue assessment, hypothesizing that subject-specific connectivity patterns play a pivotal role in understanding fatigue dynamics. By conducting a linear regression analysis of subject-specific brain networks in different frequency bands, this research aims to elucidate the relationships between frequency-specific connectivity patterns and driving fatigue.

View Article and Find Full Text PDF
Article Synopsis
  • Accurate delineation of parotid glands is essential for planning radiotherapy in head and neck cancer, ensuring precise treatment and patient safety.* -
  • This paper presents a deep learning framework called AttentionUNet, which automates the segmentation of parotid glands and demonstrates superior accuracy compared to other methods.* -
  • The framework includes additional methods for image registration, improving treatment planning by adapting to anatomical changes during radiotherapy.*
View Article and Find Full Text PDF

A combined computational and experimental study of 3D-printed scaffolds made from hybrid nanocomposite materials for potential applications in bone tissue engineering is presented. Polycaprolactone (PCL) and polylactic acid (PLA), enhanced with chitosan (CS) and multiwalled carbon nanotubes (MWCNTs), were investigated in respect of their mechanical characteristics and responses in fluidic environments. A novel scaffold geometry was designed, considering the requirements of cellular proliferation and mechanical properties.

View Article and Find Full Text PDF

We present a combined study of the mechanical properties of 3D printed scaffolds made by nanocomposite materials based on polycaprolactone (PCL). The geometry and dimensions of the three different systems is the same. Τhe porosity is 50% for all systems.

View Article and Find Full Text PDF
Article Synopsis
  • Source imaging techniques like EEG and MEG allow for high-resolution monitoring of brain activities, but traditional models often overlook the dynamic, transient nature of brain signals.
  • A novel method called μ-STAR incorporates microstate analysis and a spatio-temporal Bayesian model to optimize the reconstruction of brain activity patterns over time.
  • Initial tests with simulations and real datasets demonstrated that μ-STAR outperformed several established models, providing reliable and meaningful reconstructions of source activities that align with known brain function.
View Article and Find Full Text PDF

As a common complaint in contemporary society, mental fatigue is a key element in the deterioration of the daily activities known as time-on-task (TOT) effect, making the prediction of fatigue-related performance decline exceedingly important. However, conventional group-level brain-behavioral correlation analysis has the limitation of generalizability to unseen individuals and fatigue prediction at individual-level is challenging due to the significant differences between individuals both in task performance efficiency and brain activities. Here, we introduced a cross-validated data-driven analysis framework to explore, for the first time, the feasibility of utilizing pre-task idiosyncratic resting-state functional connectivity (FC) on the prediction of fatigue-related task performance degradation at individual level.

View Article and Find Full Text PDF
Article Synopsis
  • The study examines how tumor response during radiation therapy (RT) can impact treatment effectiveness and increase the risk of damaging surrounding healthy organs, highlighting the need for early prediction of tumor volume changes.
  • Researchers analyzed weekly CBCT images from 40 head and neck cancer patients to extract 104 radiomic features, aiming to predict significant alterations in tumor volume during RT.
  • The machine learning framework developed in this study achieved 90% accuracy in identifying key features from the first week of RT, suggesting it can efficiently forecast volumetric changes and improve treatment outcomes.
View Article and Find Full Text PDF

The prediction of schizophrenia-related psychopathologic deficits is exceedingly important in the fields of psychiatry and clinical practice. However, objective association of the brain structure alterations to the illness clinical symptoms is challenging. Although, schizophrenia has been characterized as a brain dysconnectivity syndrome, evidence accounting for neuroanatomical network alterations remain scarce.

View Article and Find Full Text PDF

In the nascent field of neuroergonomics, mental workload assessment is one of the most important issues and has an apparent significance in real-world applications. Although prior research has achieved efficient single-task classification, scatted studies on cross-task mental workload assessment usually result in unsatisfactory performance. Here, we introduce a data-driven analysis framework to overcome the challenges regarding task-independent workload assessment using a fusion of EEG spectral characteristics and unveil the common neural mechanisms underlying mental workload.

View Article and Find Full Text PDF

The cognitive processing and detection of errors is important in the adaptation of the behavioral and learning processes. This brain activity is often reflected as distinct patterns of event-related potentials (ERPs) that can be employed in the detection and interpretation of the cerebral responses to erroneous stimuli. However, high-accuracy cross-condition classification is challenging due to the significant variations of the error-related ERP components (ErrPs) between complexity conditions, thus hindering the development of error recognition systems.

View Article and Find Full Text PDF

Despite the apparent usefulness of efficient mental workload assessment in various real-world situations, the underlying neural mechanism remains largely unknown, and studies of the mental workload are limited to well-controlled cognitive tasks using a 2D computer screen. In this paper, we investigated functional brain network alterations in a simulated flight experiment with three mental workload levels and compared the reorganization pattern between computer screen (2D) and virtual reality (3D) interfaces. We constructed multiband functional networks in electroencephalogram (EEG) source space, which were further assessed in terms of network efficiency and workload classification performances.

View Article and Find Full Text PDF
Article Synopsis
  • The study examines how mental fatigue affects brain function by analyzing EEG data from 40 male subjects during low and high-demand tasks, revealing significant behavioral declines in cognitive performance before and after these tasks.
  • Results indicate that task duration correlates with increased characteristic path length in brain networks, suggesting that mental fatigue disrupts information processing efficiency.
  • The research highlights different brain network reorganizations between tasks and demonstrates high accuracy in classifying fatigue levels, supporting the potential of using functional connectivity metrics as biomarkers for monitoring fatigue.
View Article and Find Full Text PDF

Background Context: Although general hypothermia is recognized as a clinically applicable neuroprotective intervention, acute moderate local hypothermia post contusive spinal cord injury (SCI) is being considered a more effective approach. Previously, we have investigated the feasibility and safety of inducing prolonged local hypothermia in the central nervous system of a rodent model.

Purpose: Here, we aimed to verify the efficacy and neuroprotective effects of 5 and 8 hours of local moderate hypothermia (30±0.

View Article and Find Full Text PDF

Development of accurate fatigue level prediction models is of great importance for driving safety. In parallel, a limited number of sensors is a prerequisite for development of applicable wearable devices. Several EEG-based studies so far have performed classification in two or few levels, while others have proposed indices based on power ratios.

View Article and Find Full Text PDF

Efficient classification of mental workload, an important issue in neuroscience, is limited, so far to single task, while cross-task classification remains a challenge. Furthermore, network approaches have emerged as a promising direction for studying the complex organization of the brain, enabling easier interpretation of various mental states. In this paper, using two mental tasks (N-back and mental arithmetic), we present a framework for cross- as well as within-task workload discrimination by utilizing multiband electroencephalography (EEG) cortical brain connectivity.

View Article and Find Full Text PDF