Cancellation of Physiological Hand Tremors Using Compliant Robotic Assist

Physiological hand tremors are unwanted involuntary motions which affect the precision of surgeons during microsurgery. For precision surgical procedures, the magnitude of tremors is high as compared to the thickness of vessel or tissue being operated at surgical site. Hence the chances of causing irreversible damages in the nearby locations is very high, particularly in case of neural and vitreoretinal surgeries. Furthermore, human hand stability is a skill to be acquired with extensive training, it decreases with age and limits the number of surgeons qualified to perform microsurgery. Control of tremors is therefore, a major challenge for the surgeons at global level. In this paper, we have shown an effective implementation of a compliant manipulator system to successfully measure and suppress tremors. The compliant manipulators offer inherent advantageous over rigid systems, for example, more accuracy, no friction, no wear and tear, flexibility which would help preserving surgical feel and easy controllability from microsurgical point of view. Three different control schemes include feedback from lowpass filtering and an adaptive filtering are implemented and compared. The effective adaptive control scheme shows promising results in reducing tremors at the surgeon’s tool tip by ∼96%, when holding at a point and by ∼68% while carrying out a voluntary motion.Copyright © 2013 by ASME