Epidural current-steering for selective modulation of lower urinary tract function

A high-density Stim-Grid MAP spinal cord stimulation lead technology is proposed to enable the creation of predictive maps that detail how lower urinary tract nerve pathways can be activated through high- density stimulation of the sacral spinal cord and roots. These maps will enable principled development of neuromodulation therapies that use spinal cord stimulation to alleviate the burden of overactive bladder and incontinence. The lower urinary tract (LUT), consisting of the bladder, urethra and associated muscles and nerves, is an important target organ system for neuromodulation therapies as injury, disease and aging can lead to impairment and subsequent reductions in the quality of life. While existing neuromodulation devices have been implanted in over 200,000 people, device related adverse events remain common, and despite functional improvements, many people still deal with unwanted symptoms of overactive bladder and incontinence. Using electric field modelling, our multidisciplinary team has demonstrated that a two-fold increase in electrode columns and density can deliver stimulation to laterally-positioned spinal cord targets not possible with existing clinical electrodes. Furthermore, we have demonstrated feasibility of manufacturing ultra-flexible electrodes that can conform to the plexus geometry of the sacral spinal cord. The objective of this technology development effort is to develop and commercialize a 64-channel active-lead which contains 8-columns and 8 rows, and to develop maps of the accessibility of LUT peripheral nerves through spinal cord stimulation. We seek to perform three development tasks: (AIM 1) Develop a contoured and passive high-density epidural spinal-cord paddle array, (AIM 2): Develop a STIM-GRID MAP spinal cord paddle with a switch-matrix electronics package, (AIM 3) Develop maps of LUT recruitment by high-resolution stimulation of the sacral spinal cord. Our multi-disciplinary team includes device development (Micro-Leads) and bladder electrophysiology (University of Pittsburgh). In Year 1 we will create and demonstrate a 48-channel flexible and high-density passive lead and create maps that describe the selective access to the pelvic nerve, pudendal nerve and pudendal nerve branches. In Year 2 we will demonstrate a Stim-Grid MAP array with 8 columns and 8-rows (64-channels of resolution) using only 16 wires. The high-resolution array will enable us to generate maps of LUT peripheral nerve access at the spinal cord, but importantly, is immediately scalable to map other organ models with little additional development effort and time. Because the Stim-Grid MAP technology is based on well-understood implantable spinal cord lead implantation techniques, this technology could be rapidly translated to high-resolution spinal cord mapping experiments in people during an intraoperative settings in an OT3 phase.