The Strathclyde Brain Computer Interface (S-BCI) : the road to clinical translation

In this paper, we summarise the state of development of the Strathclyde Brain Computer Interface (S-BCI) and what has been so far achieved. We also briefly discuss our next steps for translation to spinal cord injured patients and the challenges we envisage in this process and how we plan to address some of them. Projections of the S-BCI project for the coming few years are also presented

Análise do eletroencefalograma durante estimulação visual por realidade virtual estereoscópica em tarefa de interceptação de bola

This Thesis developed a voluntary movement evaluation protocol, composed by a ball interception task, in a stereoscopic virtual reality environment. Thirty one righthanded volunteers participated of the experimental protocol, that simulated the point of view of goal keeper during soccer penalty defense, with three types of random stimuli, 28 each: left, centered and right ball. Two segments of EEG signals were studied in order to observe the expectancy-related potential (CNV). (1) 2 s before the beginning of the movement detected by the accelerometer and (2) 4 s between the sound of the whistle and the beginning of the movement of the ball. The epochs composed by the segment (2), present a higher CNV (p 0.05), but by the cortical responses (p < 0.05), and only after the ball initiate your trajectory (p < 0.001). Therefore, it seems that the ball direction influence the complexity of cortical responses after the beginning of the ball’s motion. Forma adicional Também disponível on-line.Esta Tese desenvolveu um protocolo de avaliação do movimento voluntário composto pela tarefa de interceptação de bola, em um ambiente de realidade virtual estereoscópica. Trinta e um voluntários destros participaram do protocolo experimental, que simulava a defesa de um pênalti do futebol a partir do ponto de vista de um goleiro, dividido em três tipos de estímulos: bola à esquerda, ao centro e à direita, sendo 28 estímulos, ordenados aleatoriamente, para cada um. Foram estudados dois trechos com vistas a observar o potencial de expectativa relacionado ao movimento (CNV): (1) 2 s antes do início do movimento detectado pelo acelerômetro e (2) 4 s compreendidos entre o som do apito e o início do movimento da bola. As épocas compostas pelo trecho (2) apresentaram uma maior CNV (p 0,05), mas sim pelas respostas corticais (p < 0,05), e somente após a bola iniciar sua trajetória (p < 0,001). Portanto, os resultados indicam que a direção da bola influencia a complexidade cortical após o início do movimento da bola

Understanding intention of movement from electroencephalograms

In this paper, we propose a new framework for understanding intention of movement that can be used in developing non-invasive brain-computer interfaces. The proposed method is based on extracting salient features from brain signals recorded whilst the subject is actually (or imagining) performing a wrist movement in different directions. Our method focuses on analysing the brain signals at the time preceding wrist movement, i.e. while the subject is preparing (or intending) to perform the movement. Feature selection and classification of the direction is done using a wrapper method based on support vector machines (SVMs). The classification results show that we are able to discriminate the directions using features extracted from brain signals prior to movement. We then extract rules from the SVM classifiers to compare the features extracted for real and imaginary movements in an attempt to understand the mechanisms of intention of movement. Our new approach could be potentially useful in building brain-computer interfaces where a paralysed person could communicate with a wheelchair and steer it to the desired direction using a rule-based knowledge system based on understanding of the subject's intention to move through his/her brain signals