Alexander Astaras

Dr. Alexander Astaras

Computer Science, American College of Thessaloniki, Greece
+2
orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

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

Representative Publications

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16 March 2021 in Sensors
Verified
Journal Article
Open access
PDF file
Kostas NizamisKostas Nizamis
Kostas Nizamis
Alkinoos AthanasiouAlkinoos Athanasiou
Alkinoos Athanasiou
Sofia AlmpaniSofia Almpani
Sofia Almpani
CDChristos Dimitrousis
Christos Dimitrousis
Alexander AstarasAlexander Astaras
Alexander Astaras
Recent advances in the field of neural rehabilitation, facilitated through technological innovation and improved neurophysiological knowledge of impaired motor control, have opened up new research directions. Such advances increase the relevance of existing interventions, as well as allow novel methodologies and technological synergies. New approaches attempt to partially overcome long-term disability caused by spinal cord injury, using either invasive bridging technologies or noninvasive human–machine interfaces. Muscular dystrophies benefit from electromyography and novel sensors that shed light on underlying neuromotor mechanisms in people with Duchenne. Novel wearable robotics devices are being tailored to specific patient populations, such as traumatic brain injury, stroke, and amputated individuals. In addition, developments in robot-assisted rehabilitation may enhance motor learning and generate movement repetitions by decoding the brain activity of patients during therapy. This is further facilitated by artificial intelligence algorithms coupled with faster electronics. The practical impact of integrating such technologies with neural rehabilitation treatment can be substantial. They can potentially empower nontechnically trained individuals—namely, family members and professional carers—to alter the programming of neural rehabilitation robotic setups, to actively get involved and intervene promptly at the point of care. This narrative review considers existing and emerging neural rehabilitation technologies through the perspective of replacing or restoring functions, enhancing, or improving natural neural output, as well as promoting or recruiting dormant neuroplasticity. Upon conclusion, we discuss the future directions for neural rehabilitation research, diagnosis, and treatment based on the discussed technologies and their major roadblocks. This future may eventually become possible through technological evolution and convergence of mutually beneficial technologies to create hybrid solutions.

1 January 2017 in BioMed Research International
Verified
Journal Article
Open access
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Alkinoos AthanasiouAlkinoos Athanasiou
Alkinoos Athanasiou
IXIoannis Xygonakis
Ioannis Xygonakis
NPNiki Pandria
Niki Pandria
PKPanagiotis Kartsidis
Panagiotis Kartsidis
GAGeorge Arfaras
George Arfaras
PANAGIOTIS BAMIDISPANAGIOTIS BAMIDIS
PANAGIOTIS BAMIDIS
Advances in neural interfaces have demonstrated remarkable results in the direction of replacing and restoring lost sensorimotor function in human patients. Noninvasive brain-computer interfaces (BCIs) are popular due to considerable advantages including simplicity, safety, and low cost, while recent advances aim at improving past technological and neurophysiological limitations. Taking into account the neurophysiological alterations of disabled individuals, investigating brain connectivity features for implementation of BCI control holds special importance. Off-the-shelf BCI systems are based on fast, reproducible detection of mental activity and can be implemented in neurorobotic applications. Moreover, social Human-Robot Interaction (HRI) is increasingly important in rehabilitation robotics development. In this paper, we present our progress and goals towards developing off-the-shelf BCI-controlled anthropomorphic robotic arms for assistive technologies and rehabilitation applications. We account for robotics development, BCI implementation, and qualitative assessment of HRI characteristics of the system. Furthermore, we present two illustrative experimental applications of the BCI-controlled arms, a study of motor imagery modalities on healthy individuals’ BCI performance, and a pilot investigation on spinal cord injured patients’ BCI control and brain connectivity. We discuss strengths and limitations of our design and propose further steps on development and neurophysiological study, including implementation of connectivity features as BCI modality.

20 March 2023 in Sensors
Verified
Journal Article
Open access
PDF file
KMKonstantinos Mitsopoulos
Konstantinos Mitsopoulos
VFVasiliki Fiska
Vasiliki Fiska
KTKonstantinos Tagaras
Konstantinos Tagaras
Athanasios PapiasAthanasios Papias
Athanasios Papias
PAPanagiotis Evaggelos Antoniou
Panagiotis Evaggelos Antoniou
Alkinoos AthanasiouAlkinoos Athanasiou
Alkinoos Athanasiou
Background: This article presents the system architecture and validation of the NeuroSuitUp body–machine interface (BMI). The platform consists of wearable robotics jacket and gloves in combination with a serious game application for self-paced neurorehabilitation in spinal cord injury and chronic stroke. Methods: The wearable robotics implement a sensor layer, to approximate kinematic chain segment orientation, and an actuation layer. Sensors consist of commercial magnetic, angular rate and gravity (MARG), surface electromyography (sEMG), and flex sensors, while actuation is achieved through electrical muscle stimulation (EMS) and pneumatic actuators. On-board electronics connect to a Robot Operating System environment-based parser/controller and to a Unity-based live avatar representation game. BMI subsystems validation was performed using exercises through a Stereoscopic camera Computer Vision approach for the jacket and through multiple grip activities for the glove. Ten healthy subjects participated in system validation trials, performing three arm and three hand exercises (each 10 motor task trials) and completing user experience questionnaires. Results: Acceptable correlation was observed in 23/30 arm exercises performed with the jacket. No significant differences in glove sensor data during actuation state were observed. No difficulty to use, discomfort, or negative robotics perception were reported. Conclusions: Subsequent design improvements will implement additional absolute orientation sensors, MARG/EMG based biofeedback to the game, improved immersion through Augmented Reality and improvements towards system robustness.

31 December 2017 in Wireless Communications and Mobile Computing
Verified
Journal Article
Open access
PDF file
Alkinoos AthanasiouAlkinoos Athanasiou
Alkinoos Athanasiou
GAGeorge Arfaras
George Arfaras
NPNiki Pandria
Niki Pandria
IXIoannis Xygonakis
Ioannis Xygonakis
NFNicolas Foroglou
Nicolas Foroglou
PANAGIOTIS BAMIDISPANAGIOTIS BAMIDIS
PANAGIOTIS BAMIDIS
Patients suffering from life-changing disability due to Spinal Cord Injury (SCI) increasingly benefit from assistive robotics technology. The field of brain-computer interfaces (BCIs) has started to develop mature assistive applications for those patients. Nonetheless, noninvasive BCIs still lack accurate control of external devices along several degrees of freedom (DoFs). Unobtrusiveness, portability, and simplicity should not be sacrificed in favor of complex performance and user acceptance should be a key aim among future technological directions. In our study 10 subjects with SCI (one complete) and 10 healthy controls were recruited. In a single session they operated two anthropomorphic 8-DoF robotic arms via wireless commercial BCI, using kinesthetic motor imagery to perform 32 different upper extremity movements. Training skill and BCI control performance were analyzed with regard to demographics, neurological condition, independence, imagery capacity, psychometric evaluation, and user perception. Healthy controls, SCI subgroup with positive neurological outcome, and SCI subgroup with cervical injuries performed better in BCI control. User perception of the robot did not differ between SCI and healthy groups. SCI subgroup with negative outcome rated Anthropomorphism higher. Multi-DoF robotics control is possible by patients through commercial wireless BCI. Multiple sessions and tailored BCI algorithms are needed to improve performance.

9 May 2025 in Applied Sciences
Verified
Journal Article
Open access
PDF file
VFVasiliki Fiska
Vasiliki Fiska
KMKonstantinos Mitsopoulos
Konstantinos Mitsopoulos
VMVasiliki Mantiou
Vasiliki Mantiou
VPVasileia Petronikolou
Vasileia Petronikolou
PAPanagiotis Evaggelos Antoniou
Panagiotis Evaggelos Antoniou
Alkinoos AthanasiouAlkinoos Athanasiou
Alkinoos Athanasiou
This study aims to present the development of a wearable prototype device consisting of soft robotic gloves (SRGs), its integration into a wearable robotics platform for sensorimotor rehabilitation, and the device’s validation experiments with individuals suffering from impaired hand motor function due to neurological lesions. The SRG is tested and evaluated by users with spinal cord injury (SCI) and stroke. The proposed system combines multiple-sensor arrays with pneumatic actuation to assist finger movement during grasping tasks. Evaluations on SCI and stroke patients revealed that the gloves consistently improved finger and grip performance. Detailed analyses indicated observable differences in sensor-derived features during actuation versus non-actuation, with statistically significant modifications appearing in both time-domain and frequency-domain metrics. Although the stroke participants exhibited greater variability, all participants were able to use the system reporting low discomfort and effort. The findings underscore the potential for personalized calibration to further optimize therapeutic outcomes. In summary, the study validates the utility of these gloves as assistive and rehabilitative modalities, and future research will focus on refining the device in the context of multimodal wearable robotics and individualized neurorehabilitation strategies.

25 June 2003
Verified
Conference Paper
Closed access
LWLei Wang
Lei Wang
TTTong Boon Tang
Tong Boon Tang
EJErik Johannessen
Erik Johannessen
Alexander AstarasAlexander Astaras
Alexander Astaras
AMA.F. Murray
A.F. Murray
DCD.R.S. Cumming
D.R.S. Cumming
There is considerable interest in the development of ultra-miniature and low-power sensor microsystems for use in applications such as medical diagnostics, environmental monitoring and other industrial applications. Such ultra-miniature sensor microsystems must contain a large diversity of complex electronics, including sensor interfaces, signal conditioning, a microprocessor core, digital signal processing, and wireless transmission technology. In this paper, we will describe the first steps towards the development of a System on Chip for such a sensor microsystem and the methodology employed to build such a microsystems.