Robust higher order repetitive control applied to human tremor suppression

Intention tremor is a common debilitating complication of Parkinson´s disease and Multiple Sclerosis and there are approximately half a million sufferers in Europe. Its distinguishing characteristic is a continuous, oscillating, almost sinusoidal, motion during visually-guided voluntary movement that increases in amplitude, becoming more apparent as the limb moves closer to a specific target, such as a cup. This paper gives results from the application of repetitive control to overcome or lessen the effects of this tremor by regulating the level of artificially induced electrical stimulation applied to a person´s limb to cause muscle contraction.