I. INTRODUCTION 1 1.1 Introduction of vitreoretinal surgery 1 1.2 Previous studies of surgical robots for vitreoretinal surgery 3 1.3 Remote Center of Motion (RCM) mechanism 5 1.4 Advantages and disadvantages of current robots 7 1.5 Study Purpose 8 II. SYSTEM DESIGN 9 2.1 Requirements of handheld manipulators 9 2.2 Design of 3-DOF manipulator 10 2.3 Kinematics of the 3-DOF manipulator 12 2.4 Control algorithm 18 III. EXPERIMENTS AND RESULTS 26 3.1 Experiment materials 26 3.2 RCM accuracy test 27 3.3 Hand tremor reduction 28 3.4 Control algorithm 31 IV. DISCUSSION 33 V. CONCLUSION 35 References 36