A multi-fingered hand prosthesis

Design and analysis of a multi-fingered hand prosthesis is presented. The hand has multi-actuated fingers, four with two joints and the thumb with three joints. Each joint is designed using a novel flexible mechanism based on the loading of a compression spring in both transverse and axial directions and using cable-conduit systems. The rotational motion is transformed to tendon-like behavior, which enables the location of the actuators far from the arm (e.g., on a belt around the waist). The forward kinematics of the mechanism is presented. It is shown that the solution of the transverse deflection of each finger segment is obtained in a general form through a Haringx model followed by an element stiffness model. A prototype finger is experimentally tested, results verified, and the hand prosthesis is built. This new design, while presents a low cost alternative, enables the actuation and control of a multi-fingered hand with relatively high degrees of freedom.