Fig. 1From: Functional electrical stimulation through direct 4-channel nerve stimulation to improve gait in multiple sclerosis: a feasibility studyComponents of the ActiGait stimulation system. The control unit worn around the patient’s waist receives a trigger signal wirelessly from the externally placed heel switch when heel lift is registered. It generates a variable electromagnetic field in the coiled antenna, which is connected to it. Transcutaneous electromagnetic induction is used to transfer the power and control signals to the implanted stimulator, which generates the stimulation pulses in 4 independent current sources. These impulses are then delivered through a dual lumen cable to 4 circularly arranged sets of electrodes within a 23 mm silicon cuff electrode, and selectively stimulate the fascicles of the common peroneal nerve and thus trigger balanced dorsiflexion of the footBack to article page