Mitigation of tremor in hands using an active mass damper

Abstract

In this study, we devised an active device in order to suppress the essential tremor in human limb. The tremor is observed in most human arms even at physically well condition that is derived from excessive stress or chills, therefore, it may cause anyone bad effect on precise operation such as welding and surgery. In this work, experiments are performed where the simulated microscopic surgery is imposed on subjects whose fingers are equipped with the active mass damper attenuating the tremor in their hands. The damper is actively driven according to the state feedback controller designed by the linear two-degrees-of-freedom vibration system model. Subjects were asked to grip a needle having a relatively small diameter using tweezers, and were also asked to insert it in a needle with a larger diameter. Tremors were measured while the subjects keep the tip of the needle in place. It is shown that the damper can attenuate vibration in human fingers.