This FastTrack SBIR proposal aims to disseminate a Functional Electrical Stimulation (FES) technology for stroke ambulation and neuromotor rehabilitation. The FastFES paradigm integrates two rehabilitation approaches, fast-paced treadmill walking and FES, in a manner that has been shown to both improve gait kinematics when the stimulation is active and to improve performance in clinical tasks with long-term intervention. Precisely timed FES patterns provide: 1) a plantarflexion (PF) assist effect during the terminal double-stance phase of gait; and 2) a dorsiflexion (DF) assist effect during the swing phase. Compared to commercially available DF-only systems, the FastFES device will provide improved paretic leg ground reaction forces during push-off as a result of the PF stimulation pattern. This will act to propel the paretic leg through the swing phase of the gait cycle and thus provide more normal gait kinematics. The technology has been developed at the University of Delaware in the laboratory of Dr. Stuart Binder-Macleod, PT, PhD. The FastFES system will include a leg-worn stimulator that is wirelessly coupled to an instrumented footswitch system. Instrumentation will provide robust and reliable gait cycle measurements to facilitate coordination of the complex FES patterns to the client's volitional gait. A clinician configuration pendant will allow clinicians to program advanced features of the device and to manage multiple users in a clinical environment. The device will also record gait cycle data to summarize its use and to aid the clinician in assessing the device's effectiveness for a particular client. The Phase I project will prove concept feasibility by demonstrating that customKYnetics' stimulator can implement the FastFES's variable frequency train (VFT) stimulation pattern such that contractions of human skeletal muscle are of comparable quality to those produced by the laboratory stimulator. The Phase II project will involve significant engineering efforts to develop the commercialization-ready system and will include a validation study at UD in which individuals with paresis secondary to a stroke iteratively evaluate device prototypes. Efficacy will be demonstrated through a long-term, single-blinded, randomized, controlled clinical intervention study. Outcomes will include kinematic assessment of the client's gait pattern (with and without stim) and assessments of changes in clinical function. The target market for the device will be rehabilitation clinics that serve the stroke market. The device will also be suitable for home/community-use. The product will provide clear differentiation over existing products in the space. The target price for a clinical system will be $5,000. The addressable market is estimated at 10,000 units for a clinical system and at least 500,000 units for a home system.