Efficacy of fractal electrodes in transcranial direct current stimulation: A computational modeling study

Fast-growing application of transcranial direct current stimulation (tDCS) as an electrotherapy technique has been motivated researchers to rationalize dosage of primary care protocol. Some important aspects in this field are pertained to modification of electrodes regarding size, position and shape of them. Recently, fractal electrodes have shown the potential to enhance neural stimulation efficiency. The purpose of current study was to address the efficacy of this newly introduced electrode on tDCS via numerical methods. An individual high resolution finite element human head model was created based on MR-scanning images. We simulated induced current density in the brain for conventional and fractal electrodes. The results demonstrate that geometry of fractal electrodes has an impact on the magnitude of current density. The peak current density for the same inward stimulus was higher (~1.3 times) for fractal electrodes in comparison with conventional type. Fractal shapes could be considered as an efficient way to provide more penetration of current density across the human brain.