The role of the tutorials is to provide a platform for a more intensive scientific exchange amongst researchers interested in a particular topic and as a meeting point for the community. Tutorials complement the depth-oriented technical sessions by providing participants with broad overviews of emerging fields. A tutorial can be scheduled for 1.5 or 3 hours.
Brain-computer Interface for Motor Rehabilitation with Multi-modal Feedback in Chronic Stroke Patients
g.tec medical engineering GmbH
Francisco Fernandes is the Regional Sales Officer of g.tec medical engineering GmbH responsible for the Portuguese market, between others. Specialised in the commercialization of medical devices, he has been working with g.tec for more than two years.
With Brain-computer interfaces (BCI) one is able to generate a control signal for external devices in real-time through the measurement of brain activation. This is especially relevant for motor rehabilitation since motor imagery-based BCI systems allow to analyze sensorimotor regions of patients’ brains and make it possible to control feedback devices that allow the patients to re-gain motor functions. In the performed study sub-acute stroke patients practiced the imagination of left and right hand movement for 25 sessions with 30 minutes each. A computer screen showed an avatar which instructed the patients to move their arms (80 trials for both left and right hand movements). The system was capable to analyze the EEG in real-time and to activate a functional electrical stimulator of the corresponding left or right hand so that the hand actually moved. Additionally, the Avatar performed the corresponding hand movement only if the classification was correct. A 9-hole PEG test was used to assess the motor function improvements. The BCI accuracy is a quite objective marker for stroke patients participating in the training task. 50 % means that patients do not follow (or are unable to follow) the task and the technician can teach them to improve it. Interesting is that if a patient achieved a very high BCI control accuracy, he could also improve his BCI performance along new training sessions, showing motivation. Most important is that within only 25 training sessions the motor functions improved. A crucial strategy is to activate first the motor cortex with the imagination. The arm movement activates the sensorimotor cortex and because the patient also sees the movement, the mirror neuron system is activated. The mirror neuron system and the sensorimotor cortex are tightly connected and this turns everything more effective. The 9-hole PEG test showed an improvement of the affected left hand movement from 1 min 30 seconds to 52 sec after 24 training sessions (healthy right hand: 26 sec) in a chronic stroke patient (64 years, impaired left side due to stroke in Feb 2014, 18 month before the study was performed). The BCI accuracy varied between 70% (session 2) to 98.5 % (session 13). The average accuracy of the first 3 training sessions reached 81 % and the ones of the last 3 sessions rose to 88 %. Previously to the training, the patient was not able to lift the arm to feed himself, afterwards the patient could reach his mouth on his own.