PROJECT SUMMARY / ABSTRACT Stroke is one of the leading causes of disability worldwide and the most common stroke-related impairment is upper-limb hemiparesis, affecting 80% of stroke patients acutely and 40% chronically. Full recovery is unlikely with current rehabilitation approaches, and as a result, stroke reduces quality of life, increases healthcare costs, and burdens caregivers. The long-term goal of this project is to leverage assistive bionic devices to restore motor function and promote long-term neuro-regeneration, ultimately replacing more expensive and less effective rehabilitation approaches with a patient-centered rehabilitation strategy. The objective of this proposal is to control assistive bionic exoskeletons and quantify stroke recovery with electromyographic (EMG) recordings of residual muscle activity from the paretic arm. Our central hypothesis is that an EMG-controlled powered orthosis – that assists individuals in activities of daily living – can be used as a patient-specific rehabilitative tool that improves stroke recovery. Aim 1 will adapt dexterous EMG-control algorithms for upper-limb orthoses, and then demonstrate improved hand dexterity and functional mobility for stroke patients. Aim 2 will utilize large EMG datasets over time to precisely quantify changes in muscle strength and spasticity throughout recovery and to provide robust long-term control of assistive devices via deep learning. Aim 3 consists of a pilot study to determine the feasibility of patient-specific assistive-device-driven rehabilitation. The proposed research is innovative because it will address gaps in knowledge critical to merging assistive and rehabilitative devices. These findings are significant because they will enable devices that can immediately and simultaneously promote usage, strengthen muscles, and provide closed-loop visual feedback – thereby merging multiple effective rehabilitation strategies into a single holistic approach. This proposal will have a positive impact on society by increasing rehabilitation compliance, promoting independence and improving recovery outcomes for stroke patients, ultimately reducing healthcare costs and improving patients’ quality of life.