A Soft Robotic Wrist Orthosis Using Textile Pneumatic Actuators For Passive Rehabilitation

Abstract

Wearable soft robots can be effective tools for rehabilitation due to their inherent safety and compliance. Challenges, however, exist regarding the development of suitable on-body actuation methods. Furthermore, the majority of existing soft wearable devices are not accessible and easy to use for those with physical disabilities. This paper presents the design, fabrication, and characterization of a soft robotic wrist orthosis to achieve flexion and extension for continuous passive motion therapy. First, we developed bending textile pneumatic actuators that could be mechanically programmed to conform to the target joint's anatomy when mounted on the body. The textile pneumatic actuators achieved up to 2.24 Nm of torque at 124 kP <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$a$</tex> . We then embedded the textile pneumatic actuators into a soft wrist orthosis that we designed to ensure it was easy to don/doff without assistance. To determine the operating pressures and range of motion achievable by our soft robotic wrist orthosis, we conducted a device evaluation study with three healthy individuals. Our device achieved over 100 degrees of flexion/extension assistance at operating pressures below 90 kPa. This work takes the first steps towards developing a wearable soft robotic device that can deliver passive therapy at home without the need for a physical therapist or assistant.