Design of a variable stiffness index finger exoskeleton

Abstract

This paper presents the design and experimentation of a variable stiffness index finger exoskeleton consisting of four-bar mechanisms actuated by a linear actuator. The lengths of the four-bar mechanism were optimized so that it can follow a recorded index fingertip trajectory. The mechanism has a fixed compliance at the coupler of the four-bar link and a variable compliance at the linear actuator that moves the four-bar. The skeletal shape of the coupler of the finger link has been optimized using FEM. The exoskeleton can apply a constant fingertip force irrespective of the position of the fingers.

Experimental Characterization of A-AFiM, an Adaptable Assistive Device for Finger Motions

“…Thus, we have fingers flexion and extension, as shown in Figure 1. In the references [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23], several types of robots help in rehabilitation processes, this is because the mechanisms can generate controlled movement in the joints. The rehabilitation process allows people to regain control of their limbs after an illness or traumatic event.…”

“…In references [13,14], the authors proposed a design of a lightweight forearm exoskeleton for fine-motion rehabilitation using a slider crack and four-bar mechanism with more links and an actuator. Other authors, as in reference [15] using a rigid-soft combined mechanism for a hand exoskeleton, proposed a highly compact device.…”