Computational analysis of a high-density electrode to scale the electric field geometry and intensity for neurostimulation

High-density grid electrodes can be configured to spatially scale the neurostimulation fields and enable the control of depth, intensity, and stimulation vectoring. In this study, we computationally analyze a high-density cluster electrode (HDCE) technology to measure its scalability and its effects on human tissue. The models are developed in Ansys using the Maxwell 3D Design modeler. More than 24 HDCE electrode configurations were analyzed and compared to standard 8 mm Ag/AgCl electrodes. It was found that the HDCE electrode configurations can be selected to emulate the electric field properties to within 1% of a standard 8 mm Ag/AgCl electrode. Moreover, increasing the number of active electrode contacts in the HDCE non-linearly increases tissue voltage and field intensity at various tissue depths. Specifically, it was found that the sensitivity of tissue voltage and field intensity decreases with the number of active HDCE electrode contacts. Similarly, the different spatial configurations of the HDCE can change the field shape by up to 54%, while the field intensity can be scaled by up to 186%. Similarly, the vector of the stimulation field (i.e., stimulation vector) through the tissues can be adjusted by shifting active electrode positions. When comparing these electrodes to standard 8 mm Ag/AgCl electrodes the results suggest a transformative impact of these technologies to optimize neurostimulation applications. The work presented here is part of a larger project aiming to develop next-generation scalable neurostimulation system that improve rehabilitation outcomes, and provide new adaptive solutions for personalized healthcare.