Application of phased array systems to deep brain stimulation

Deep brain stimulation (DBS) is a clinical tool adopted to treat various neurological disorders, including chronic pain, incontinence and movement disorders. One major limitation of commercial DBS systems is the inability to control the distribution of the electric field around the target region, resulting in the activation of both target and non-target neural clusters. The authors have previously proposed a method to provide controlled stimulation by the adoption of phased array technology. A model was developed to study the behavior of wavefronts, generated by phased arrays, in tissue. This study represents an improvement to this model, where the frequency-dependence of the dielectric properties of brain tissue is taken into account. Results have shown that the applicability of phased array stimulation depends on the frequency of stimulation, with frequencies in the region of GHz providing the best trade-off between field steering, focusing and tissue penetration.