Chronic Deep Brain Stimulation (DBS) emerged in the last decade as a revolutionary new approach to the treatment of neurological and psychiatric disorders. DBS is currently approved for treatment of Parkinson's Disease (PD) and Essential Tremor and is showing promise for treatment of dystonia, intractable epilepsy, major depression, and obsessive-compulsive disorder. DBS therapy involves controllable electrical stimulation through a lead having four relatively large electrodes that implanted in the targeted region of the thalamus or basal ganglia. While DBS therapy is generally safe and effective for reducing cardinal symptoms of the approved diseases, it often has significant behavioral and cognitive side effects and limits on performance. Additionally, experimental and computational studies have revealed complex mechanisms of action for specific disease states. The growing body of clinical and scientific evidence strongly suggests that details such as fine electrode positioning, selectivity, and precise stimulation patterning are very important for clinical outcomes. The proposed Deep Brain Stimulating Array (or DBSA) is an electrode array designed for long-term stimulation and is comprised of many microelectrode sites, therefore providing significantly enhanced stimulation selectivity, precision, and tunability. The technical innovation of this device is the use of a large number of smaller sites (64 sites) that can be used individually or in selectable groups in order to achieve more diverse electrical stimulation patterns. This array of sites will significantly expand the tunable range of the device in order to better fit the DBS therapy to the patient. It will also provide the capability of incorporating feedback control through neural recordings (32 sites) for eventual on-demand DBS, similar to that of modern cardiac pacemakers. The specific goals of this SBIR Phase I proposal are to develop a prototype version of the DBSA and to evaluate its feasibility for selective and tunable DBS therapy. The prototype DBSA will be used to evaluate critical packaging, materials, and functional attributes of the device. The first specific aim is to develop a prototype DBSA, with the expected outcome of this aim being a validated first generation prototype device. The second specific aim is to evaluate the electrical stimulation characteristics of the DBSA. The expected outcome of this aim will be an analytical and experimental analysis of the stimulation capabilities of the DBSA. The third specific aim is to evaluate the chronic tissue reactions to the DBSA. The expected outcomes of this aim are preliminary data on the safety and biocompatibility of the chosen materials, geometrical specifications and stimulation protocols. NeuroNexus is leading this project in collaboration with FHC, the University of Michigan and consultants from the Cleveland Clinic. The multi-disciplinary project team possesses the experience, skill sets, and resources to meet the project goals and, in the process, to move the field of neural engineering ahead. The primary objective of this project is the development of an advanced electrode technology used for deep brain stimulation (DBS) therapy. DBS is a common therapeutic approach for the treatment of Parkinson's Disease, and potentially other movement related disorders. [unreadable] [unreadable] [unreadable]