Soft Robotics in Body Assistance: An Intelligent Rehabilitation Device with Soft Continuum Actuation

Abstract

In an effort to improve rehabilitation devices, the applications of soft robotics technologies to prosthetics and physical therapy was explored, particularly due to the benefits of the inherent properties of soft materials. A conceptual design for a soft robotics device prototype is proposed to assist with physical therapy for wrist tendonitis and arthritis, carpal tunnel syndrome, fractures and sprains, and compromised motor skills due to chronic stroke. The device assists in four motions that are commonly performed in wrist therapy: flexion, extension, and rotation (clockwise and counterclockwise) using soft pneumatic actuators to guide movements. The distinct directions were achieved by varying the lateral and radial strain limiting layers. The device uses embodied intelligence to make the device dynamically adaptable in real time, allowing for a customizable recovery process. A detailed model of the device was developed and the viability of the design was assessed using a suite of state-of-the-art simulation tools and limited hardware prototyping. Simulations were performed through integration of Rhinoceros 3D, Grasshopper 3D, Firefly, an Arduino microcontroller, biosensors, Python scripting, and visual parametric programming. Pressure and materials were simulated and tested in Simulia Abaqus and Autodesk Fusion 360. Several parametric variations were tried using simulations and the predictions revealed that rubber silicone at a pressure of 10 kiloPascals is the optimal choice.