Among the most significant goals of therapeutic exercise following stroke are maintaining strength and endurance of paretic muscles and aiding in restoration of functional use of the affected limbs. One relatively new and promising device that may address these aims is the NuStep TRS4000 recumbent cross trainer, which provides a coupled reciprocal leg/arm extension exercise movement against graded loads while the subject remains seated for safety and comfort. We propose to augment the TRS4000 with functional electrical stimulation (FES), which has the potential to produce the required reciprocal stepping pattern thereby exercising the lower extremity musculature, providing a cardiorespiratory exercise opportunity, and providing the spinal cord and brain with targeted afferent feedback that may aid in restoration of function of the affected limbs. We hypothesize that the FES component may improve both efficacy and availability of TRS4000 exercise for a significant percentage of potential users. We anticipate that successful implementation would lead to a viable commercial product, which would meet a clinically relevant need and build upon existing clinical acceptance of the NuStep device. The goals of this Phase I project are: 1) to modify and instrument a TRS4000 device for interface to a proprietary 2-channel adaptive stimulator; 2) to develop NuStep-specific adaptive stimulation control algorithms; 3) to validate controller design through simulation studies; and 4) to demonstrate feasibility of the approach through a pilot study that will be performed at the University of Cincinnati's Neuromotor Recovery and Rehabilitation Laboratory at Drake Rehabilitation Center (Cincinnati, OH) under the direction of Stephen Page, PhD. The feasibility study will include recruitment of three (3) subjects that have experienced a stroke who will each participate in 3 sessions of FES-augmented NuStep exercise. Sessions will be managed and patients continually monitored by an Exercise Physiologist to assure their safety. Feasibility will be defined as the ability for the adaptive stimulator to develop client-specific stimulation patterns to elicit the proposed recumbent stepping movement across subjects and visits without intervention of therapists or research engineers. Phase II work may include stimulator modifications to simplify instrumentation and to stimulate a larger number of muscles, mechanical modifications to the TRS4000 to improve efficacy in motor reeducation applications, and a clinical trial of sufficient sample size to demonstrate efficacy of the FES-enabled TRS4000 for exercise with the potential for motor re-education improvements. The target market for the device will be rehabilitation clinics that provide care to individuals following stroke. customKYnetics, Inc. will seek a Strategic Alliance partnership with NuStep, Inc. for manufacturing, marketing, sales, and distribution of the FES-augmented TRS4000 with the goal of achieving a price point of $5000. / Relevance Stimulation Augmented Recumbent Stepper for Stroke Rehabilitation Applicant Institution: customKYnetics, Inc. (PI: Hartman, Eric C.) The proposed work may benefit public health through development of an electrical stimulation augmented recumbent stepping machine (TRS4000, NuStep, Inc.) indicated for exercise and motor reeducation following stroke (700,000 cases per year) or spinal cord injury (11,000 cases per year). Compared to the stand-alone NuStep device, the electrical stimulation component may improve efficacy of the exercise for users with marginal volitional control and may improve availability of the exercise for individuals with insufficient volitional control to otherwise participate. ? ?