Preliminary Results on the Integration of Muscle Oximetry Sensors for Exoskeleton Interfaces

Providing assistance in wearable robots based on exertion levels enables targeted and energy-efficient support. Traditional fatigue estimators, such as surface electromyography (sEMG) are predominantly reactive, identifying fatigue only after it has occurred. Near-Infrared Spectroscopy (NIRS) offers a complementary approach by providing early insights into muscle oxygenation, with oxygen depletion strongly correlating with muscle fatigue, thereby enabling proactive monitoring. This study integrates chip-based NIRS sensors into a physical interface to monitor muscle oxygen saturation during both static and dynamic conditions. The experimental protocol included an occlusion test, a low-intensity walking trial, and a high-intensity cycling trial to evaluate the sensor's performance under varying levels of exhaustion. Preliminary results demonstrate the sensor's sensitivity to oxygenation changes, underscoring its potential for fatigue-adaptive assistance in wearable devices.