Vibro-Tactile Stimulation for Finger Discrimination in P300 BCI for Post-Stroke Rehabilitation: Study on Healthy Subjects

Currently, rehabilitation of post-stroke patients is an actual medical task. Actively developing technologies of brain-computer interfaces, based on the process of motor imagery, are already used in clinical practice for rehabilitation tasks. However, they have a small number of commands while provided control is anthropomorphic. One of the alternatives is the use of BCI based on vibro-tactile P300. Nevertheless, the selection of stimulation parameters for stable registration of the P300 is still an actual task. Moreover, application of vibro-tactile stimulation affecting the individual fingers of the hand makes it possible to restore fine motor skills. For this purpose, two different versions of the of vibro-tactile stimulator layouts were developed. In this study such exposure parameters as the duration of stimuli in the range from 40 to 600 ms and the frequency of stimulation from 1 to 2 Hz were considered. Different types of vibration motors also varied. The values of amplitudes and latencies of the evoked potentials P300 in the leads Cz and Pz were obtained. The difference between typical and registered latency values can be associated with a long transient process of vibration motors, which was confirmed by the quantitative assessment. Conclusions about the recommended stimulation mode are made and further plans for the modification of the stand are indicated.