Treating drop-foot in hemiplegics: The role of matrix electrode

We present advantages of the “intelligent matrix electrode” for providing selective correction of drop-foot in hemiplegic individuals. The matrix electrode which integrates stimulating and sensing parts could allow the emulation of the appropriate electrode shape and size; thereby, provision of selective stimulation that leads to functional movement and online adaptation of the electrode during the application. The need for selective stimulation follows recent findings about therapeutic effects of electrical stimulation in neurorehabilitation. The matrix electrode comprises small fields that can be made conductive and a controller that allows computerized selection of the fields being conductive. Here we present results from a study in nine hemiplegics. The matrix electrode was positioned over the peroneal nerve and primary dorsiflexor muscles and we estimated the movement of the foot by measuring the ankle joint angle. We found that the branched tree type shape and size of the electrode vary substantially when stimulating over the dorsiflexor muscles individuals in the study. We confirmed very high sensitivity to the position of small electrode when stimulating over the nerve. This indicates that the use of “intelligent matrix electrode” is favorable compared with conventional electrodes since it can adapt to individual and secure selective stimulation.