Serafeim Perdikis

Dr. Serafeim Perdikis

Brain-Computer Interfaces and Neural Engineering Laboratory, School of Computer Science, University of Essex, Colchester, Essex, UK

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

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20 June 2018 in Nature Communications
Verified
Journal Article
Open access
PDF file
ABA. Biasiucci
A. Biasiucci
RLR. Leeb
R. Leeb
III. Iturrate
I. Iturrate
Serafeim PerdikisSerafeim Perdikis
Serafeim Perdikis
AAA. Al-Khodairy
A. Al-Khodairy
JMJosé del R. Millán
José del R. Millán
Brain-computer interfaces (BCI) are used in stroke rehabilitation to translate brain signals into intended movements of the paralyzed limb. However, the efficacy and mechanisms of BCI-based therapies remain unclear. Here we show that BCI coupled to functional electrical stimulation (FES) elicits significant, clinically relevant, and lasting motor recovery in chronic stroke survivors more effectively than sham FES. Such recovery is associated to quantitative signatures of functional neuroplasticity. BCI patients exhibit a significant functional recovery after the intervention, which remains 6–12 months after the end of therapy. Electroencephalography analysis pinpoints significant differences in favor of the BCI group, mainly consisting in an increase in functional connectivity between motor areas in the affected hemisphere. This increase is significantly correlated with functional improvement. Results illustrate how a BCI–FES therapy can drive significant functional recovery and purposeful plasticity thanks to contingent activation of body natural efferent and afferent pathways.

10 May 2018 in PLOS Biology
Verified
Journal Article
Open access
PDF file
Serafeim PerdikisSerafeim Perdikis
Serafeim Perdikis
Luca ToninLuca Tonin
Luca Tonin
SSSareh Saeedi
Sareh Saeedi
CSChristoph Schneider
Christoph Schneider
JMJosé del R. Millán
José del R. Millán
This work aims at corroborating the importance and efficacy of mutual learning in motor imagery (MI) brain–computer interface (BCI) by leveraging the insights obtained through our participation in the BCI race of the Cybathlon event. We hypothesized that, contrary to the popular trend of focusing mostly on the machine learning aspects of MI BCI training, a comprehensive mutual learning methodology that reinstates the three learning pillars (at the machine, subject, and application level) as equally significant could lead to a BCI–user symbiotic system able to succeed in real-world scenarios such as the Cybathlon event. Two severely impaired participants with chronic spinal cord injury (SCI), were trained following our mutual learning approach to control their avatar in a virtual BCI race game. The competition outcomes substantiate the effectiveness of this type of training. Most importantly, the present study is one among very few to provide multifaceted evidence on the efficacy of subject learning during BCI training. Learning correlates could be derived at all levels of the interface—application, BCI output, and electroencephalography (EEG) neuroimaging—with two end-users, sufficiently longitudinal evaluation, and, importantly, under real-world and even adverse conditions. Noninvasive brain–computer interface (BCI) based on imagined movements can restore functions lost to disability by enabling spontaneous, direct brain control of external devices without risks associated with surgical implantation of neural interfaces. We hypothesized that, contrary to the popular trend of focusing on the machine learning aspects of BCI training, a comprehensive mutual learning methodology could strongly promote users’ acquisition of BCI skills and lead to a system able to succeed in real-world scenarios such as the Cybathlon event, the first international competition for disabled pilots in control of assistive technology. Two severely impaired participants with chronic spinal cord injury (SCI) were trained following our mutual learning approach to control their avatar in a virtual BCI race game. The evolution of the training process, including competition outcomes (gold medal, tournament record), substantiates the effectiveness of this type of training. Most importantly, the present study provides multifaceted evidence on the efficacy of subject learning during BCI training. Learning correlates could be derived at all levels of the interface—application, BCI output, and electroencephalography—with two end-users, longitudinal evaluation, and, importantly, under real-world and even adverse conditions.

1 October 2013 in Artificial Intelligence in Medicine
Verified
Journal Article
Closed access
RLRobert Leeb
Robert Leeb
Serafeim PerdikisSerafeim Perdikis
Serafeim Perdikis
Luca ToninLuca Tonin
Luca Tonin
ABAndrea Biasiucci
Andrea Biasiucci
MTMichele Tavella
Michele Tavella
JMJosé del R. Millán
José del R. Millán

9 November 2017 in IEEE Robotics and Automation Letters
Verified
Journal Article
Closed access
LRLuca Randazzo
Luca Randazzo
IIIñaki Iturrate
Iñaki Iturrate
Serafeim PerdikisSerafeim Perdikis
Serafeim Perdikis
JMJosé del R. Millán
José del R. Millán
Hand sensorimotor impairments are among the most common consequences of injuries affecting the central and peripheral nervous systems, leading to a drastic reduction in the quality of life for affected individuals. Combining wearable robotic exoskeletons and human-machine interfaces is a promising avenue for the restoration and substitution of lost and impaired functions for these users. In this study, we present a novel hand exoskeleton, mano, designed to assist and restore hand functions of people with motor disabilities during activities of daily living (ADL) and in neurorehabilitative scenarios. Compared to state-of-the-art devices, our system is fully wearable, portable, and minimally obtrusive on the hand. The exoskeleton can actively control flexion and extension of all fingers, while allowing natural somatosensorial interactions with the environment surrounding the users. We evaluated the device from four different perspectives. A mechanical characterization, showing that the exoskeleton can cover more than 70% of healthy hand workspace and it can achieve forces at the fingertips sufficient for ADL. A functional characterization, where we showed how two users who suffered from spinal cord injuries were able to perform several ADL for the first time since their accidents. Third, we evaluated the system from a neuroimaging perspective, showing that the device can elicit EEG brain patterns typical of natural hand motions. We finally exemplified the control of the hand exoskeleton within an exemplar framework, a brain-machine interface scenario, showing that motor intention can be decoded for a continuous control of the device. Overall, our results showed that the device represents an ecological solution for use both in ADL and in scenarios aimed at promoting sensorimotor recovery.

15 July 2020 in IEEE Systems, Man, and Cybernetics Magazine
Verified
Journal Article
Closed access
Serafeim PerdikisSerafeim Perdikis
Serafeim Perdikis
JMJosé del R. Millán
José del R. Millán
Brain-machine interface (BMI) technology has rapidly matured over the last two decades, mainly thanks to the introduction of artificial intelligence (AI) methods, in particular, machine-learning algorithms. Yet, the need for subjects to learn to modulate their brain activity is a key component of successful BMI control. Blending machine and subject learning, or mutual learning, is widely acknowledged in the BMI field. Nevertheless, we posit that current research trends are heavily biased toward the machine-learning side of BMI training. In this article, we take a critical view of the relevant literature, and our own previous work, to identify the key issues for more effective mutual-learning schemes in translational BMIs that are specifically tailored to promote subject learning. We identify the main caveats in the literature on subject learning in BMI, in particular, the lack of longitudinal studies involving end users and shortcomings in quantifying subject learning, and pinpoint critical improvements for future experimental designs.

1 October 2010
Verified
Conference Paper
Closed access
Luca ToninLuca Tonin
Luca Tonin
RLRobert Leeb
Robert Leeb
MTMichele Tavella
Michele Tavella
Serafeim PerdikisSerafeim Perdikis
Serafeim Perdikis
JMJosé del R. Millán
José del R. Millán
This paper discusses and evaluates the role of shared control approach in a BCI-based telepresence framework. Driving a mobile device by using human brain signals might improve the quality of life of people suffering from severely physical disabilities. By means of a bidirectional audio/video connection to a robot, the BCI user is able to interact actively with relatives and friends located in different rooms. However, the control of robots through an uncertain channel as a BCI may be complicated and exhaustive. Shared control can facilitate the operation of brain-controlled telepresence robots, as demonstrated by the experimental results reported here. In fact, it allows all subjects to complete a rather complex task, driving the robot in a natural environment along a path with several targets and obstacles, in shorter times and with less number of mental commands.