Functional Design and Kinematic Analysis of a Novel 3RS End-Effector Robot for Wrist Rehabilitation and Assistance

Robot-aided rehabilitation is increasingly important to meet the challenges posed by an ageing population and a global shortage of healthcare workers. This paper presents a 3RS (3 Revolute Joints - 1 Spherical Joint) end-effector robot for wrist joint rehabilitation and daily activity assistance. It assists flexion/extension and radial/ulnar deviation avoiding the problem of joint misalignment typical of exoskeletons and covering the workspace of the hand. The design parameters are tuned to ensure high dexterity and safe user interaction, laying a solid foundation for the development of a functional prototype.