Design, Characterization, and Impedance Limits of a Hand Robot

Previous work has expanded the planar MIT-MANUS to include an anti-gravity robot for shoulder-and-elbow and wrist robot. In this paper we present the "missing link": a hand module. We will discuss in detail the design and characterization of this module. It consists of a single degree of freedom mechanism in a novel statorless configuration, which enables rehabilitation of grasping. The system uses the kinematic configuration of a double crank and slider where the members are linked to stator and rotor; a free base motor, i.e., a motor having two rotors that are free to rotate instead of a fixed stator and a single rotatable rotor. A cylindrical structure, made of six panels and driven by the relative rotation of the rotors, is able to increase its radius linearly, moving or guiding the hand of the patients during grasping This module completes our development of robots for the upper-extremity affording for the first time a whole-arm rehabilitation experience.