Individual Robot-Aided Rehabilitation: From Assist-As-Needed Toward Challenge-As-Needed

This paper introduces a novel method for monitoring patients' ability to perform hip flexion motions and adapting the range of motion based on their individual capabilities. The aim is to optimize rehabilitation outcomes by appropriately challenging patients during the early stages of mobilization. Leveraging the concept of Challenge-As-Needed (CAN) control, we implemented this approach on a robotic device for very early mobilization, building upon the Assist-As-Needed (AAN) control framework. Testing was conducted with a single healthy subject, demonstrating potential for future clinical applications. Results indicate the effectiveness of our supplementary method in adjusting the range of motion (ROM) of robotic rehabilitation devices. By employing real-time sensing and making minor adjustments, our approach successfully identified instances where patients were ready to expand their maximal hip ROM, thus accommodating their needs effectively. Within the study, a pre-study was undertaken to identify the most suitable control variable, guiding the design and implementation of our control algorithm. Application of this algorithm to patient data yielded promising outcomes, suggesting its potential to enhance rehabilitation outcomes in future clinical settings.