Public Summary Month 7/2011

In Brain-Computer-Interface settings the task of the subjects is to deliberately modify brain activation to communicate. The imagery of motor actions and to focus attention to different flickering objects are two communication strategies implemented in the first period.

We intend to select an object to be grasped by presenting flickering lights at different frequencies, while the subjects have to focus their attention to one object. From brain waves we decode the frequency of the attended object.

 

Fig. 1 Stimulus setup. Top: Objects are presented on discs, which can flicker at a defined frequency. Bottom: The flicker frequency is physiologically represented in the MEG signal

A first version of a new algorithm for grasp and trajectory planning is developed. The algorithm generates point poles on each surface triangle of the grasping target. Between these poles and the ones placed on the manipulator a force field is assumed. The impact of the forces on the manipulator is simulated and used as trajectory.

Fig. 2 Robotic manipulator used in this experiment