2037 A Novel Closed-Loop Neuromodulation Device for Restoration of Function in Post-Stroke Paresis

INTRODUCTION: Post-stroke paresis is a major health and economic burden and 62% of these patients do not recover functional use of their extremities at 6 months post-stroke. Elbow flection, specifically, is essential for feeding, dressing, grooming, and other activities of daily life; as such, severity of arm impairment is associated with a decrease of health-related quality of life, restricted social participation, and subjective well-being. METHODS: The device comprising four essential components—a cuff electrode, an implantable pulse generator (IPG), a wearable electromyography (EMG) skin patch, and a portable EMG signal processing and transmission box. An in-vivo stroke model employed a 50 kg young adult male Yucatan minipig. An external controller detected EMG activity, which communicated with an implanted stimulation board to trigger nerve stimulation and muscle contraction to create a seamless loop that enables instantaneous and volitional motor control. RESULTS: The device functioned effectively using a closed-loop EMG feedback controller, delivering biphasic current pulses when EMG activity exceeded a predefined threshold. The system was configured to adjust the stimulation current in proportion to the amplitude of the EMG input, enhancing volitional control and functional adaptability for potential clinical application. Quantitative analysis of the EMG response indicated robust stimulation without inducing muscle fatigue. Additionally, fibrillation potentials and twitch movements corresponding to MRC scores of 0 and 1, respectively, were successfully utilized as input triggers. CONCLUSIONS: This innovative device and platform was capable of restoring functional movement in a post-stroke animal model. While this early data is promising, further studies are needed to test its feasibility in a chronic animal study prior to progressing to an early feasability study.