Exoskeleton for Upper Limb Rehabilitation (EULR) with 3D printing technology based on force sensor

The paper addresses the significant challenge of limited accessibility and high costs associated with commercial exoskeletons for hand rehabilitation, particularly for individuals with low to middle incomes. The aim of this study is to design and develop a low-cost, 3D-printed hand exoskeleton that integrates force sensor technology, providing a more adaptable solution for rehabilitation. The methodology involves creating a prototype that combines 3D printing with real-time monitoring of upper limb (elbow) movements and forces, ensuring personalized treatment for patients. The design incorporates a lightweight structure, powered by a rechargeable LiPo battery, and utilizes mini ESP32 microcontrollers to collect the sensor parameters and drive the servo motor, enhancing user experience and functionality. Results indicate that the proposed exoskeleton significantly reduces costs to approximately 98.4 US$ per unit, compared to existing products priced above 1,500 USD. The mean root mean square error (RMSE) for the exoskeleton's finger movements was measured at 0.498° ± 0.709°, demonstrating high accuracy in tracking hand movements. The mean linearity error of load cell across all data points was 0.2292 %. These results indicate that the load cell maintains good linearity and accuracy within the calibrated range, and is suitable for precise force measurements in static applications. Additionally, the integration of force sensors allows for precise feedback during rehabilitation exercises, promoting better outcomes. The study concludes that this innovative approach not only makes hand rehabilitation more accessible but also encourages further research and development in the field. By providing an open-source design, the research fosters collaboration among researchers and developers, paving the way for future enhancements and adaptations of the exoskeleton to meet diverse patient needs. Overall, this work contributes to advancing rehabilitation technology, ultimately improving the quality of life for individuals recovering from neuromuscular disorders.