Bioelectrical and Neuroengineering Commons^™

Interfacing Neural Models: Biocompatibility And Fabrication Of A Flexible, Self-Folding Microelectrode Array, Fernando A. Pesantez Torres

Electronic Theses & Dissertations (2024 - present)

Neurodegenerative diseases pose a formidable challenge in modern medicine, necessitating the development of advanced research tools that can elucidate their complex pathophysiology. Recent advancements in neurodegenerative disease research have led to the development of three-dimensional (3D) neurodegenerative organoids using human induced pluripotent stem cells (hiPSCs). These organoids closely mimic human brain architecture and functionality, providing a valuable tool for understanding complex diseases. Additionally, the ability to generate and study brain organoids consistently and in large quantities holds potential for a controlled in vitro setting and high-throughput drug screening. However, these models are complex systems requiring specialized maintenance, analysis, and manipulation …

Microwell Fabrication For Impedance And Ac Measurements Of Isolated Ventricular Cardiomyocytes, Fallon Wenck

Multidisciplinary Studies Theses and Dissertations

Electrophysiological behavior of human hearts have been extensively studied for hundreds of years. Even with elucidation of not just biological function, but also time and frequency-dependent current flow, the sheer intricacy of in vivo cardiac tissue function remains somewhat enigmatic. All while heart disease has been the leading cause of death in the United States for over a century, with its rates of occurrence still increasing annually [1]. Thus, new research techniques and tools to quantify cardiac function are still being pursued at smaller and smaller scales to decrease research/innovation time, cost, and diagnostic ambiguity. In fact, it remains incredibly …

Interfacing A Hirudo Medicinalis Retzius Cell With Insulated Gate Of Mosfet, Rachel M. Smith

Master's Theses

Much work has been done to study the external stimulation of nervous tissue as well as the transmission of neural signals to electronics. Peter Fromherz was one of the pioneers in this area of electrophysiology, with a series of experiments in the 1990s that aimed to characterize and optimize the interface between neural tissue and transistors. In this thesis, Kurt Sjoberg and I interfaced a Retzius cell isolated from a Hirudo medicinalis ganglion with the insulated gate of a MOSFET. The goal was to see change in membrane potential that could be related Fromherz’s original 1991 work. Our experimental setup …

Electrophysiology Of Basal Ganglia (Bg) Circuitry And Dystonia As A Model Of Motor Control Dysfunction, Deepak Kumbhare

Theses and Dissertations

The basal ganglia (BG) is a complex set of heavily interconnected nuclei located in the central part of the brain that receives inputs from the several areas of the cortex and projects via the thalamus back to the prefrontal and motor cortical areas. Despite playing a significant part in multiple brain functions, the physiology of the BG and associated disorders like dystonia remain poorly understood. Dystonia is a devastating condition characterized by ineffective, twisting movements, prolonged co-contractions and contorted postures. Evidences suggest that it occurs due to abnormal discharge patterning in BG-thalamocortocal (BGTC) circuitry. The central purpose of this study …

A Novel Visual Stimulation Paradigm: Exploiting Individual Primary Visual Cortex Geometry To Boost Steady State Visual Evoked Potentials (Ssvep), Marta Isabel Vanegas Arroyave

Dissertations and Theses

The steady-state visual evoked potential (SSVEP) is an electroencephalographic response to flickering stimuli generated in significant part by activity in primary visual cortex (V1). SSVEP signal-to-noise ratio is generally low for stimuli that are located in the visual periphery, at frequencies higher than 20 Hz, or at low contrast. Because of the typical "cruciform" geometry of V1, large stimuli tend to excite neighboring cortical regions of opposite orientation, likely resulting in electric field cancellation. In Study 1, we explored ways to exploit V1 geometry in order to boost scalp SSVEP amplitude via oscillatory summation, by manipulating flicker-phase offsets among angular …

Implementation Of Medicinal Leech Preparation To Investigate The Connection Between The Motor Neuron And Muscle Fiber Via Sharp Electrode Electrophysiology, Chandra Nikole Miller

Master's Theses

There are forty registered organophosphates in the United States and they range from pesticides and insecticides to nerve agents or neurotoxins such as sarin. Organophosphates (OP’s) have been used in chemical warfare for years and tend to lead to death due to an attack on the nervous system. Chemical assays and mass microscopy have been used to assess the concentration of OP’s in the environment, but both methods require the body to metabolize the OP first, which can be detrimental to the victim. It is crucial to come up with a method to investigate and detect these neurotoxins without causing …

Focusing Electromagnetic Radiation In Dielectric Media, Mark A. Migliaccio Jr.

Electrical & Computer Engineering Theses & Dissertations

Bioelectrics and microwave imaging requires an ultra-wideband (UWB) antenna to deliver intense, short electromagnetic pulses into biological targets for the purpose of therapy and imaging. Two antennas with different focal distances, predicted by a two­ dimensional model, have been designed for focusing electromagnetic radiation in the near field.

Focusing is achieved through the use of prolate spheroidal reflector antennas with a conical wave launcher submerged in water. For an ultra-wideband feed signal, with a rise time of 200 picoseconds, the maximum electric field was found to be close to the edge of the reflector, a result that differs from the …