Project Summary: Post-stroke hand impairment is highly prevalent and severely restricts functional ability and independence. In fact, every 40 seconds a new stroke occurs, and stroke is recognized as the leading cause of long-term disability. Yet, there is no assistive device to help hand function at home, every day, during activities of daily living. Existing devices such as hand-opening orthoses are expensive (e.g. Myomo and Bioness are priced at $7,500+), uncomfortable, bulky, and meant for use during short therapy sessions as opposed to during daily living. Thus their impact is limited. Consequently, the development of efficacious and affordable assistive device is of paramount importance. This proposal addresses this critical gap by providing an innovative patent-pending technology. The ?TheraBracelet? is a wristband applying imperceptible white-noise vibration to skin. TheraBracelet is efficacious, as it has been shown to immediately improve chronic stroke survivors? touch sensation and hand dexterity in preliminary studies. TheraBracelet is affordable by using only a low-cost vibrator. TheraBracelet is also translational, because a vibrator strategically placed at the wrist does not interfere with dexterous finger motions, and it is low-risk by involving only imperceptible vibration on skin. These practicalities assure easy adoption in home environment for large impact on sensorimotor impairment. The essential next step toward commercialization, thus the objective of this Phase I proposal, is to determine the feasibility and safety of using this assistive device all day every day for a month during daily activity, and to determine if TheraBracelet?s instant effects are sustained during prolonged use. This objective will be accomplished in a double-blinded, randomized, controlled, crossover design study. Feasibility (compliance of using the device everyday) and safety (no worsening of sensation, strength, dexterity, pain, spasticity, skin irritation) will be assessed for the treatment condition compared to the control condition (wearing the device without vibration) through weekly evaluations. The feasibility and safety level comparable to those of wearing a watch and of a comparable FDA-approved device will support commercial viability of TheraBracelet with necessary regulatory approvals. In addition, TheraBracelet?s instant benefits in improving hand function will be assessed weekly. Persistence of TheraBracelet?s instant benefits across all weekly evaluations will support durability (i.e. desensitization to vibration does not occur during extended daily use over a one-month period). The knowledge of feasibility, safety, and durability will pave the way toward commercialization of this novel technology. This project is expected to lead to an assistive wristband that increases hand function during activities of daily living, thus increasing independence and quality of life and reducing caregiver burden for a large number of stroke survivors with hand impairment.