Selective stimulation of a peripheral nerve: correction of drop foot in three patients

We present an evaluation of an implantable system with a monopolar half-cuff for selective stimulation of the common peroneal nerve in three hemiplegic patients. The stimulus proposed in this work for effecting selective stimulation of the superficial region of the human common peroneal nerve in more physiological order were current, charge balanced, and biphasic pulses with a rectangular cathodic component, and exponential decay anodic component delayed for 50 /spl mu/s. Results show that a half-cuff electrode is capable of making a long term selective activation, mainly of those muscles that contribute to strong dorsal flexion and moderate eversion of the hemiplegic's foot. Moreover, significant improvements of gait dynamics without excessive eversion were observed.