Biomimetic orthosis for the neurorehabilitation of the elbow and shoulder (BONES)

TLDR

The paper introduces BONES, a novel 4‑degree‑of‑freedom pneumatically‑actuated upper‑limb rehabilitation device designed to provide kinematic, range‑of‑motion, and force‑generation capabilities for elbow and shoulder neurorehabilitation. BONES employs a parallel mechanism with two passive sliding rods pivoting on a fixed frame, driven by four pneumatic actuators for shoulder motion and a fifth for elbow flexion/extension, enabling a wide range of motion, low inertia, and direct‑drive force generation. The device successfully generates internal/external arm rotation without a ring bearing, mirroring human forearm biomechanics.

Abstract

This paper presents a novel design for a 4 degree of freedom pneumatically-actuated upper-limb rehabilitation device. BONES is based on a parallel mechanism that actuates the upper arm by means of two passive, sliding rods pivoting with respect to a fixed structural frame. Four, mechanically-grounded pneumatic actuators are placed behind the main structural frame to control shoulder motion via the sliding rods, and a fifth cylinder is located on the structure to control elbow flexion/extension. The device accommodates a wide range of motion of the human arm, while also achieving low inertia and direct-drive force generation capability at the shoulder. A key accomplishment of this design is the ability to generate arm internal/external rotation without any circular bearing element such as a ring, a design feature inspired by the biomechanics of the human forearm. The paper describes the rationale for this device and its main design aspects including its kinematics, range of motion, and force generation capability.