Toward clinically applicable steady-hand eye robot for vitreoretinal surgery

This paper reports new developments and optimizations for clinical use of the Steady-Hand Eye Robot for vitreoretinal surgery. Vitreoretinal surgery requires precise micromanipulation of delicate tissues. Surgical performance is limited by physiological hand tremor, fatigue, poor kinesthetic feedback, as well as patient movement. The previously developed Steady- Hand Eye Robot has been extensively used in in vivo experiments. Several safety and ergonomic limitations observed in the in vivo environment serve as motivation for a novel robot wrist design. The new robot wrist consists of a symmetric remote center of motion (RCM) tilt mechanism and a slim tool holder with a quick release mechanism for the surgical instruments. The RCM tilt mechanism provides a tilt motion range of ±45° and a stiffness of 21 N/mm. Two different release force thresholds for the quick release mechanism were designed. The soft configuration requires 2-3 N to retract the surgical instruments while the hard configuration requires 5-6 N.