Fig 1.
Electrode placements and model detail.
Two different electrode sizes were simulated to apply GVS: 35 cm2 (A-C) and ~3 cm2 (D-F). The electrodes were placed on the skin-tissue mask in a Bilateral-Bipolar configuration. (G): The two electrode sizes were overlaid on the same head model geometry to highlight final placement with respect to the anatomy. (H): To highlight the region of interest in the model geometry with respect to other tissues and the stimulation electrode, certain tissue masks were made semi-transparent. (I): The dashed section in (H) is expanded to further highlight model detail.
Fig 2.
Comparison of GVS induced current flow using small- and large-size electrodes.
Columns A (A1, A2, A3) and B (B1, B2, B3) correspond to the 35 cm2 and 3 cm2 electrodes, respectively. The current streamlines from both models are overlaid in C1. C2 and C3 indicate the difference in induced E-field due to the two electrode sizes. The first row (A1, B1 and C1) shows the current streamline plots with the brain, SCC and otolith organs masks visible to provide enhanced visualization of current flow with respect to their anatomy. The second row (A2, B2, and C2) shows the induced brain surface E-field plots. Similarly, the third row (A3, B3, and C3) shows the induced E-field plots on the vestibular labyrinth.
Table 1.
Maximum induced E-field (based on 99th percentile) in the brain and vestibular regions across the two models.
The percentage increase of E-field with respect to the larger electrode model is noted in the final column.