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  • Is it necessary to show virtual limbs in action observation neurorehabilitation systems?
    Publication . Modroño, Cristián; Bermúdez, Sergi; Cameirão, Mónica; Pereira, Fábio; Paulino, Teresa; Marcano, Francisco; Hernández-Martín, Estefanía; Plata-Bello, Julio; Palenzuela, Nereida; Núñez-Pádron, Daniel; Pérez-González, José M; González-Mora, José L
    Action observation neurorehabilitation systems are usually based on the observation of a virtual limb performing different kinds of actions. In this way, the activity in the frontoparietal Mirror Neuron System is enhanced, which can be helpful to rehabilitate stroke patients. However, the presence of limbs in such systems might not be necessary to produce mirror activity, for example, frontoparietal mirror activity can be produced just by the observation of virtual tool movements. The objective of this work was to explore to what point the presence of a virtual limb impacts the Mirror Neuron System activity in neurorehabilitation systems.
  • Virtual reality based rehabilitation speeds up functional recovery of the upper extremities after stroke: a randomized controlled pilot study in the acute phase of stroke using the rehabilitation gaming system
    Publication . Cameirão, Mónica da Silva; Bermúdez i Badia, Sergi; Duarte, Esther; Verschure, Paul F. M. J.
    Given the incidence of stroke, the need has arisen to consider more self-managed rehabilitation approaches. A promising technology is Virtual Reality (VR). Thus far, however, it is not clear what the benefits of VR systems are when compared to conventional methods. Here we investigated the clinical impact of one such system, the Rehabilitation Gaming System (RGS), on the recovery time course of acute stroke. RGS combines concepts of action execution and observation with an automatic individualization of training. METHODS. Acute stroke patients (n = 8) used the RGS during 12 weeks in addition to conventional therapy. A control group (n = 8) performed a time matched alternative treatment, which consisted of intense occupational therapy or non-specific interactive games. RESULTS. At the end of the treatment, between-group comparisons showed that the RGS group displayed significantly improved performance in paretic arm speed that was matched by better performance in the arm subpart of the Fugl-Meyer Assessment Test and the Chedoke Arm and Hand Activity Inventory. In addition, the RGS group presented a significantly faster improvement over time for all the clinical scales during the treatment period. CONCLUSIONS. Our results suggest that rehabilitation with the RGS facilitates the functional recovery of the upper extremities and that this system is therefore a promising tool for stroke neurorehabilitation.
  • NeuRow: an immersive VR environment for motor-imagery training with the use of brain-computer interfaces and vibrotactile feedback
    Publication . Bermúdez i Badia, Sergi; Ferreira, André; Vourvopoulos, Athanasios
    Motor-Imagery offers a solid foundation for the development of Brain-Computer Interfaces (BCIs), capable of direct brain-to-computer communication but also effective in alleviating neurological impairments. The fusion of BCIs with Virtual Reality (VR) allowed the enhancement of the field of virtual rehabilitation by including patients with low-level of motor control with limited access to treatment. BCI-VR technology has pushed research towards finding new solutions for better and reliable BCI control. Based on our previous work, we have developed NeuRow, a novel multiplatform prototype that makes use of multimodal feedback in an immersive VR environment delivered through a state-of-the-art Head Mounted Display (HMD). In this article we present the system design and development, including important features for creating a closed neurofeedback loop in an implicit manner, and preliminary data on user performance and user acceptance of the system.
  • The combined impact of virtual reality neurorehabilitation and its interfaces on upper extremity functional recovery in patients with chronic stroke
    Publication . Cameirão, Mónica S.; Bermúdez i Badia, Sergi; Duarte, Esther; Frisoli, Antonio; Verschure, Paul F. M. J.
    Background and Purpose—Although there is strong evidence on the beneficial effects of virtual reality (VR)-based rehabilitation, it is not yet well understood how the different aspects of these systems affect recovery. Consequently, we do not exactly know what features of VR neurorehabilitation systems are decisive in conveying their beneficial effects. Methods—To specifically address this issue, we developed 3 different configurations of the same VR-based rehabilitation system, the Rehabilitation Gaming System, using 3 different interface technologies: vision-based tracking, haptics, and a passive exoskeleton. Forty-four patients with chronic stroke were randomly allocated to one of the configurations and used the system for 35 minutes a day for 5 days a week during 4 weeks. Results—Our results revealed significant within-subject improvements at most of the standard clinical evaluation scales for all groups. Specifically we observe that the beneficial effects of VR-based training are modulated by the use/nonuse of compensatory movement strategies and the specific sensorimotor contingencies presented to the user, that is, visual feedback versus combined visual haptic feedback. Conclusions—Our findings suggest that the beneficial effects of VR-based neurorehabilitation systems such as the Rehabilitation Gaming System for the treatment of chronic stroke depend on the specific interface systems used. These results have strong implications for the design of future VR rehabilitation strategies that aim at maximizing functional outcomes and their retention. Clinical Trial Registration—This trial was not registered because it is a small clinical study that evaluates the feasibility of prototype devices.
  • Combining virtual reality and a myoelectric limb orthosis to restore active movement after stroke: a pilot study
    Publication . Bermúdez i Badia, Sergi; Lewis, Ela; Bleakley, Scott
    We introduce a novel rehabilitation technology for upper limb rehabilitation after stroke that combines a virtual reality (VR) training paradigm with a myoelectric robotic limb orthosis. Our rehabilitation system is based on clinical guidelines and is designed to recruit specific motor networks to promote neuronal reorganization. The main hypothesis is that the restoration of active movement facilitates the full engagement of motor control networks during motor training. By using a robotic limb orthosis, we are able to restore active arm movement in severely affected stroke patients. In a pilot evaluation, we have successfully deployed and assessed our system with three chronic stroke patients by means of behavioral data and self-report questionnaires. The results show that our system is able to restore up to 60% of the active movement capability of patients. Further, we show that we can assess the specific contribution of the biceps/triceps movement of the paretic arm in a VR bilateral training task. Questionnaire data show enjoyment and acceptance of the developed rehabilitation system and its VR training task.
  • Eye gaze patterns after stroke: correlates of a VR action execution and observation task
    Publication . Alves, Júlio; Vourvopoulos, Athanasios; Bernardino, Alexandre; Bermúdez i Badia, Sergi
    The concept of a partially shared neural circuitry between action observation and action execution in healthy participants has been demonstrated through a number of studies. However, little research has been done in this regard utilizing eye movement metrics in rehabilitation contexts.In this study we approach action observation and action execution by combining a virtual environment and eye tracking technology. Participants consisted of stroke survivors, and were required to perform a simple reachand-grab and place-and-release task with both their paretic and non-paretic arm. Results showed congruency in gaze metrics between action execution and action observation, for distribution and duration of gaze events. Furthermore, in action observation, longer smooth pursuit segments were detected when observing the representation of the paretic arm, thus providing evidence that the affected circuitry may be activated during observation of the simulated action. These results can lead to novel rehabilitation methods using virtual reality technology.
  • An integrative virtual reality cognitive-motor intervention approach in stroke rehabilitation: a pilot study
    Publication . Faria, A. L.; Vourvopoulos, A.; Cameirão, M. S.; Fernandes, J. C.; Bermúdez i Badia, Sergi
    Stroke is one of the most common causes of acquired disability, leaving numerous adults with cognitive and motor impairments, and affecting patient’s capability to live independently. In post-stroke it is imperative to initiate a process of intensive rehabilitation and personalized objectives to maximize functional cognitive and motor recovery. Virtual Reality (VR) technology is being widely applied to rehabilitation of stroke, however, not in an integrative manner. Like traditional rehabilitation, these new tools mostly focus either in the cognitive or in the motor domain, which can take to a reduced impact in the performance of activities of daily living, most of them dual-task. Assuming the existence of cognitive and motor recovery interdependence, RehabNet proposes a holistic approach. Here we present a one-month long pilot study with three stroke patients whose training was a game-like VR version of the Toulouse-Piéron cancellation test, adapted to be performed by repetitive arm reaching movements. A standardized motor and cognitive assessment was performed pre and post intervention. The first results on this intervention support a holistic model for rehabilitation of stroke patients, sustaining interdependence on cognitive and motor recovery. Furthermore, we observed that the impact of the integrative VR approach generalizes to the performance of the activities of daily living.
  • Combined cognitive-motor rehabilitation in virtual reality improves motor outcomes in chronic stroke–a pilot study
    Publication . Faria, Ana L.; Cameirão, Mónica S.; Couras, Joana F.; Aguiar, Joana R. O.; Costa, Gabriel M.; Bermúdez i Badia, Sergi
    Stroke is one of the most common causes of acquired disability, leaving numerous adults with cognitive and motor impairments, and affecting patients' capability to live independently. Virtual Reality (VR) based methods for stroke rehabilitation have mainly focused on motor rehabilitation but there is increasing interest toward the integration of cognitive training for providing more effective solutions. Here we investigate the feasibility for stroke recovery of a virtual cognitive-motor task, the Reh@Task, which combines adapted arm reaching, and attention and memory training. 24 participants in the chronic stage of stroke, with cognitive and motor deficits, were allocated to one of two groups (VR, Control). Both groups were enrolled in conventional occupational therapy, which mostly involves motor training. Additionally, the VR group underwent training with the Reh@Task and the control group performed time-matched conventional occupational therapy. Motor and cognitive competences were assessed at baseline, end of treatment (1 month) and at a 1-month follow-up through the Montreal Cognitive Assessment, Single Letter Cancelation, Digit Cancelation, Bells Test, Fugl-Meyer Assessment Test, Chedoke Arm and Hand Activity Inventory, Modified Ashworth Scale, and Barthel Index. Our results show that both groups improved in motor function over time, but the Reh@Task group displayed significantly higher between-group outcomes in the arm subpart of the Fugl-Meyer Assessment Test. Improvements in cognitive function were significant and similar in both groups. Overall, these results are supportive of the viability of VR tools that combine motor and cognitive training, such as the Reh@Task. Trial Registration: This trial was not registered because it is a small clinical study that addresses the feasibility of a prototype device.
  • Virtual reality with customized positive stimuli in a cognitive-motor rehabilitation task: a feasibility study with subacute stroke patients with mild cognitive impairment
    Publication . Cameirão, Mónica S.; Pereira, Fábio; Bermúdez i Badia, Sergi
    Virtual Reality applications for integrated cognitive and motor stroke rehabilitation show promise for providing more comprehensive rehabilitation programs. However, we are still missing evidence on its impact in comparison with standard rehabilitation, particularly in patients with cognitive impairment. Additionally, little is known on how specific stimuli in the virtual environment affect task performance and its consequence on recovery. Here we investigate the impact in stroke recovery of a virtual cognitive-motor task customized with positive stimuli, in comparison to standard rehabilitation. The positive stimuli were images based on individual preferences, and self-selected music (half of the sessions). 13 participants in the subacute stage of stroke, with cognitive and motor deficits, were allocated to one of two groups (VR, Control). Motor and cognitive outcomes were assessed at end of treatment (4-6 weeks) and at a 4-week followup. Both groups showed significant improvements over time in functional ability during task performance, but without changes in motor impairment. Cognitive outcomes were modest in both groups. For participants in the VR group, the score in the task was significantly higher in sessions with music. There were no statistical differences between groups at end of treatment and follow-up. The impact of VR therapy was lower than in similar studies with stroke patients without cognitive deficits. This study is a first step towards understanding how VR could be shaped to address the particular needs of this population.
  • Impact of age, VR, immersion, and spatial resolution on classifier performance for a MI-based BCI
    Publication . Blanco-Mora, D. A.; Aldridge, A.; Jorge, C.; Vourvopoulos, A.; Figueiredo, P.; Bermúdez i Badia, S.
    There are many factors outlined in the signal processing pipeline that impact brain–computer interface (BCI) performance, but some methodological factors do not depend on signal processing. Nevertheless, there is a lack of research assessing the effect of such factors. Here, we investigate the impact of VR, immersiveness, age, and spatial resolution on the classifier performance of a Motor Imagery (MI) electroencephalography (EEG)-based BCI in naïve participants. We found significantly better performance for VR compared to non-VR (15 electrodes: VR 77.48 ± 6.09%, non-VR 73.5 ± 5.89%, p = 0.0096; 12 electrodes: VR 73.26 ± 5.2%, non-VR 70.87 ± 4.96%, p = 0.0129; 7 electrodes: VR 66.74 ± 5.92%, non-VR 63.09 ± 8.16%, p = 0.0362) and better performance for higher electrode quantity, but no significant differences were found between immersive and non immersive VR. Finally, there was not a statistically significant correlation found between age and classifier performance, but there was a direct relation found between spatial resolution (electrode quantity) and classifier performance (r = 1, p = 0.0129, VR; r = 0.99, p = 0.0859, non-VR).