Modeling and percept of transcorneal electrical stimulation in humans

Abstract

Retinal activation via transcorneal electrical stimulation (TcES) in normal humans was investigated by comparing subject perception, model predictions, and brain activation patterns. The preferential location of retinal stimulation was predicted from 3-D admittance modeling. Visual cortex activation was measured using positron emission tomography (PET) and (18)F-fluorodeoxyglucose (FDG). Two different corneal electrodes were investigated: DTL-Plus and ERG-Jet. Modeling results predicted preferential stimulation of the peripheral, inferior, nasal retina during right eye TcES using DTL-Plus, but more extensive activation of peripheral, nasal hemiretina using ERG-Jet. The results from human FDG PET study using both corneal electrodes showed areas of visual cortex activation that consistently corresponded with the reported phosphene percept and modeling predictions. ERG-Jet was able to generate brighter phosphene percept than DTL-Plus and elicited retinotopically mapped primary visual cortex activation. This study demonstrates that admittance modeling and PET imaging consistently predict the perceived location of electrically elicited phosphenes produced during TcES.

Electrical Stimulation as a Means for Improving Vision

“…37 Accordingly, both DTL-Plus and ERG-Jet electrodes showed visual cortex activation in association with the reported phosphene. 46 …”

Flexible Polyimide Microelectrodes Array for Transcorneal Electrical Stimulation

“…Manufacturing process using standard micro fabrication techniques LIMEMS-Poly MUPs. The Polyamide flexible substrate have demonstrated its biocompatibility, feasibility and efficiency [17] [18].…”

“…TES has demonstrated great potential in alleviating the problems and disabilities produced by these diseases [2]- [5]. However, the relationship between the parameters of TES and the neuro-protective effect of TES on axotomised Retinal Ganglion Cells (RGCs) or its effects on other retinal structures is still unclear [6] [7]. To have a better understanding of that relationship, a strategy is required to fire selected ganglion cells and other cell types [8]- [12].…”

On the computation of a retina resistivity profile for applications in multi-scale modeling of electrical stimulation and absorption

“…Consolidating findings from these single cell studies into cellular network models can then be used to analyze the role of connectivity (Publio et al 2009, 2012, Wang et al 2011). Other studies have focused instead on prosthetic designs rather than anatomy and physiology, considering geometry and placement of electrodes, differentiating existing devices and suggesting future design constraints (Rattay and Resatz 2004, Behrend et al 2011, Moghaddam et al 2014, Xie et al 2011). Work has also been done to more accurately represent the cellular composition of tightly packed cells and confined extracellular space, as shown in Meffin et al (2014) and Tahayori et al (2014).…”