Integrating Finite Element Method for Multiscale Modeling and Simulation of Retinal Ganglion Cell Stimulation Strategies.

The finite element method (FEM) has become an increasingly popular tool for the computational modeling of multiscale biological systems, including the electrode-tissue interface and the behavior of individual neural cells. However, a significant challenge in these studies is integrating multiple levels of complexity, each with its biophysical properties. This paper presents a single platform solution for modeling these multiscale systems using the finite element method. The proposed method combines different finite element formulations tailored to the specific biophysical properties of each scale into a single unified simulation platform. The results of this method are compared to experimental data to demonstrate the accuracy and efficacy of the proposed approach. With the goal of eliciting the most significant possible response from the retinal ganglion cell's (RGC) multiple components, we devised an electrical stimulation strategy and electrode placement setup that took into account both the RGC's horizontal and vertical location. We found that the activity in a single RGC model could be elicited by a cathodic pulse of amplitude 34 µA. We observed that the optimum electrode placement for a neural response is around the initial axon segment, 30 μm from the soma, and 10 μm above the RGC. Our results show that the proposed method can accurately capture the complex behavior of these multiscale systems and provide a valuable tool for further research in retinal prostheses.Clinical Relevance- To develop efficient electrical stimulation schemes for retinal prosthesis applications, this research can shed light on the behavior of the electrode-tissue interface and individual neural cells. Electrical stimulation of RGCs has shown promise in the application of retinal prostheses. Still, a thorough understanding of the electrode-induced electric field is essential for the design of effective and safe stimulation protocols. Electrical stimulation's side effects may require knowledge of multiple physics disciplines (such as thermal or structural deformation owing to implant placement inside the eye). Finding a solution to diseases that cause vision impairment could be aided by a finite element method (FEM) framework that simulates the neuronal response to extracellular electrical stimulation for realistic 3D cell and electrode geometries.