[IEEE 2017 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Jeju Island, South Korea (2017.7.11-2017.7.15)] 2017 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Proof of concept Laplacian estimate derived for noninvasive tripolar concentric ring electrode with incorporated radius of the central disc and the widths of the concentric rings