Masters Applied Projects

Project 9

Utilizing Finite Element Modeling to Investigate the Effects of Mechanical Deformation on Peripheral Nerve Axon Recruitment during Electrical Stimulation


Student:

Devika Dileep

Mentors:

Dr. James Abbas, PhD - University of Arkansas
Dr. Jit Muthuswamy, PhD - Arizona State University, SBHSE
Dr. Rosalind Sadleir, PhD - Arizona State University, SBHSE

YouTube Link:
View the video link below before joining the zoom meeting

Zoom Link:
https://asu.zoom.us/j/81177292379


Abstract:
The peripheral nervous system (PNS) is the part of the nervous system that resides outside the brain and spinal cord. As the PNS innervates the rest of the body, the peripheral nerves experience a variety of mechanical stresses through everyday movement. All body movement causes subtle mechanical deformation resulting in axons rearranging within the peripheral nerve. This project considers an upper-limb prosthetic that utilizes electrodes implanted within a fascicle inside a nerve to provide tactile sensory feedback. During movement, the axons stimulated by the electrode can change, interfering with prosthetic function or causing unwanted effects. This study utilizes finite element modeling to apply a mechanical load to the nerve fascicle to determine how axons rearrange. First, a script in MATLAB generates a cross-section of the fascicle with a given number of axons. Next, FEBio mechanically loads a 3D model of the fascicle with the generated axon locations to determine the new axon arrangement. The study also characterizes which axons are recruited or activated given electrical stimulation from the electrode. This part of the study utilizes NEURON, a simulation environment for modeling neuron networks. The activation profiles of the mechanically loaded and unloaded fascicle are compared to determine the relationship between nerve deformation and axon recruitment. In the future, the groundwork in this project can help determine optimal electrode implantation for neuroprosthetic function.