High-level framework in wearable exosuits involving virtual reality and human-robot intent interaction for gait intervention

Abstract

The ankle joint plays a crucial role in walking by providing positive power to propel the body forward. Dynamic changes occur throughout the gait cycle, with the ankle storing energy during the stance phase and releasing it during push-off. Compromised ankle motion leads to abnormal gait patterns in various populations, including the elderly, stroke patients, and individuals with neurological disorders. External interaction through powered devices, such as exoskeletons, is frequently used in rehabilitation to improve gait. This chapter discusses the development of a novel high-level control architecture for real-time application with an active ankle exoskeleton. The intervention force profile generated by the exoskeleton is tailored to be gait-adaptive and specific to multimodal walking, incorporating the rhythmicity of the gait phase using adaptive frequency oscillators and a biomechanically driven gait characterization unit. The feasibility of the controller was tested on seven young adults, demonstrating its potential effectiveness in assisting with activities of daily living. To enhance the impact of the intervention paradigm, the chapter proposes integrating a dual-motor task into a virtual reality environment. This task encourages users to utilize their foot-to-foot transition phase while throwing a ball, thereby implicitly engaging with the exoskeleton’s assistive and resistive interventions at the ankle joint. Testing this integrated paradigm revealed changes in muscle activity during the assistance and resistive modes, highlighting the potential for impactful and interactive user feedback during real-time interventions in activities of daily living. Dual-task paradigms in virtual reality environments shed light on the interplay between motor skills and cognitive functions, offering insights into coordinated movements and balance improvement. In conclusion, the study presents a comprehensive approach to gait interventions, integrating advanced control architectures with virtual reality environments to provide personalized and engaging interventions.