Engineering Commons^™

Oculomotor Control In Patients With Parkinson's Disease, George Gitchel

Theses and Dissertations

There have been few studies investigating the eye movement behavior of Parkinson’s disease patients during fixation. This study objectively measured the eye movements of 36 patients with Parkinson’s disease, and 20 age matched controls. Stimuli consisted of ten standardized text passages first organized by Miller and Coleman. In addition, subjects followed a randomly displaced step jump target motion. Pendular nystagmus was found in all Parkinson’s subjects, with an average frequency of 7.44 Hz. Saccadic peak velocity and duration along the main sequence were not statistically different from controls. A slower rate of reading was also noted in the Parkinson’s group …

Automated Methods For Fiber Diameter Measurement Of Fibrous Scaffolds, Anna Bulysheva

Theses and Dissertations

The purpose of this work was to develop an automated method of measuring fiber diameters of electrospun scaffolds from scanning electron microscopy images of these scaffolds. Several automated methods were developed and evaluated by comparison to known values and data obtained via the standard manual method. Simulated images with known diameters were used as test images to evaluate the accuracy of each measurement technique. Eight scanning electron microscopy images were also used for the evaluation of the automated methods compared to the standard manual method. All diameter measurements were made in pixels. Five new automated methods coded in MATLAB were …

The Development Of A Mesenchymal Stem Cell Based Bone Graft System, Sarina Sinclair

All Dissertations

Greater than 5.5 million fractures are sustained by Americans each year, accounting for more than 500,000 bone graft surgeries. Bone grafts are the second most transplanted material, surpassed only by blood. The current 'gold standard' for bone grafting involves harvesting bone material from the patient's iliac crest, due to its osteoinductive properties. Unfortunately, the surgery required to harvest material from the iliac crest causes additional pain for the patient, relies on a limited amount of available bone tissue, and results in, on average, a 30% rate of donor site morbidity. Both natural and synthetic substitutes have been developed to avoid …

Hydrogel Compositions For Nonviral Gene Delivery, Eunhee Cho

All Dissertations

The incorporation of nonviral vectors into biomaterial matrices has been employed to improve localization at the implant site and to protect from loss by clearance or extracellular barriers. However, several limitations such as detrimental crosslinking mechanisms, uncontrolled burst release require improved design of matrix-based gene delivery systems that provides sustained and controlled vector release as well as overcomes extracellular barriers to gene transfer in proximity to target cells. The long-term objective of this dissertation project is to provide the basis for the eventual creation of tissue engineering scaffolds that combine structural and biological activity through the creation of composite materials …

Creation Of Bioactive Surfaces To Modulate Cell Behavior Using Surface Initiated Photoiniferter-Mediated Graft Photopolymerization, Nihar Shah

All Dissertations

Biomaterials widely used in biomedical applications still face biocompatibility issues arising from non-specific protein adsorption on the foreign surface, and the consequent undesired cell response. Emerging evidence suggests that imparting specific bioactivity to the biomaterial's surface to elicit favorable response from cells, (like osseointegration of joint implants and endothelialization of stents) can yield much better biocompatibility results when combined with passive prevention of protein adsorption. In more complex diseases like spinal cord injury and cardiomyopathy, specific biomolecules are required to elicit desired cell responses for successful regeneration. However, for success of such biomolecule based strategies, the effects of various parameters …

Designing An Instrument Based On Native Fluorescence To Determine Soil Microbial Content At A Mars Analog Site, Heather D. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For this research project we designed an instrument to detect bacteria via biomolecular fluorescence. We introduce the current understanding of astrobiology, our knowledge of life beyond Earth, and the commonality of Earth life as it pertains to the search for life on Mars. We proposed a novel technique for searching for direct evidence of life on the surface of Mars using fluorescence. We use the arid region of the Mojave Desert as an analog of Mars. Results indicate the fluorescence of the biotic component of desert soils is approximately as strong as the fluorescence of the mineral component. Fluorescence laboratory …

Synchronization And Media Exchange In Large-Scale Caenorhabditis Elegans Cultures, Jason D. Brown

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The nematode Caenorhabditis elegans is a model organism for understanding sensory molecules of multicellular organisms. Ovulating hermaphrodites produce putative pheromone(s) that cause male attraction. Because pheromones are produced in such small quantities, adult conditioned-media from large-scale synchronous culture is necessary to analyze these pheromones. Current protocols for culture synchronization have volume constraints that limit large-scale synchronous cultures and current methodology for adult conditioned-media production is impractical.

Modification of Tangential Flow Filtration (TFF) systems was investigated for use as a method to increase the volume limits of bleach egg harvest for C. elegans culture synchronization. Also, an adult retention device built …

Covalent Immobilization Of L1 Neural Cell Adhesion Molecule To Acrylated Tetronicâ® Hydrogels For Neural Regeneration, Rebecca Cribb

All Dissertations

Spinal cord injuries cost the United States $20 billion per year, with an existing patient population of 256,000 growing by an estimated 12,000 each year. Current clinical therapies for spinal cord injury are limited to spinal immobilization and realignment via traction, surgery, administration of methylprednisolone sodium succinate (MPSS) within eight hours post-injury, and rehabilitation exercises. While these therapies are important and may minimize damage and restore limited function, there is a dire clinical need for treatments to address the growing population of chronically-injured patients.
Varying degrees of axonal regeneration and functional recovery following spinal cord injury have been achieved in …

Neomycin Enhances Glutaraldehyde Crosslinking And Glycosaminoglycan Stability In Bioprosthetic Heart Valves, Vincent Friebe

All Theses

The native heart valve will open and close an astonishing 3 billion times in the average lifetime, implicating immense biomechanical ramifications that necessitate near-flawless structure and functional behavior. Deviations from this idyllic function as a result of heart valve disease (HVD) affect millions of individuals worldwide and result in over 275,000 heart valve replacements worldwide every year. Glutaraldehyde (GLUT) cross-linked porcine aortic heart valves, a common type of bioprosthetic heart valve (BHV), are used frequently in these valve replacement surgeries. The native valve leaflets entail a tri-composite design of type I collagen, elastin and glycosaminoglycans (GAGs), each of which are …

Vibration Analysis Of Heavy-Duty Diesel Vehicles, Christopher Jack Campbell

Masters Theses

Truck drivers are more susceptible than other workers to lower back pain and spinal disorders caused by whole body vibrations, which are among the most common long term health effects for drivers. The dynamic behavior of trucks can be modeled and simulated to improve the design of the trucks, which can reduce the exposure of drivers to whole body vibrations.

The main purposes of this study are to analyze vibrations for different manufacturers and road types, and to create a computer-based model using Adams to predict vibration anywhere on the model using acceleration data collected previously from on-road tests of …

Identification And Quantification Of Cotton Yield Monitor Errors, Jason Clay Head

Masters Theses

Cotton yield monitors are an important part of a precision agriculture program and are becoming widely used by cotton producers for making management decisions. Members of the cotton industry have shown interest in using cotton yield monitors for collecting data from production scale variety yield trials (experiments that test yield performance for numerous varieties). Weighing boll buggies are the current industry standard for measuring yield in variety trials. This process is time consuming and requires extra equipment and labor. The ability to use a yield monitor for measuring yield would streamline variety trial harvesting. Recommendations for the Ag Leader cotton …

Single Cell Impedance Measurements Using Microfabricated Electrodes And Labview Graphical Programming, Stephanie Sophia Hernandez

Master's Theses

This Master’s Thesis project consists of the research, design, and fabrication of a system that could perform broadband impedance measurements (1kHz-20Mhz) of single cells using National Instruments Labview data acquisition and programming in coordination with a single cell capture device. Presented first is the background information on cells and their electrical properties, along with background in micro-total-analysis systems as well as impedance spectroscopy. Experimental Methods are then discussed for the electrode design, cellular modeling in COMSOL, fabrication methods, and Labview 8.0 Set-up and programming. Measurements were performed using the single-cell capture device on saline, yeast cells, and a polysterene bead. …

Laser Scanning Confocal Microscopy (Lscm): An Application For The Detection Of Morphological Alterations In Skin Structure, Shea C. Smith

Master's Theses

Laser scanning confocal microscopy (LSCM) is an optical imaging technique that provides improved resolution and sensitivity over conventional methods of optical microscopy. However, the cost of most commercial LSCM systems exceeds the financial limitations of many smaller laboratories. The design of a custom LSCM created at a fraction of the cost of a commercial model is discussed in this paper.

The increase in the incidence rate of skin cancer in the world today is alarming, as such, it is essential to provide an early, rapid and effective method for in vivo diagnostics of human skin tissue. LSCM is capable of …

A Computational Model Of Apoptotic Osteocyte Correlation To Cortical Bone Remodeling Parameters, Michael Stephen Alexander

Master's Theses

The onset of osteoporosis caused by aging, disease states, and post-menopausal conditions significantly impacts patient quality of life, required healthcare funding, personal autonomy losses from increased fracture risk and the subsequent corrective surgery. Research has indicated that osteocyte apoptosis may be a key parameter in bone remodeling, raising the possibility of remodeling rate modulation for the mitigation of bone mass resorption. By developing therapies that target osteocyte apoptosis, it may be possible to prevent undesired bone remodeling activity while maintaining a healthy balance between damage formation in the form of microcracks induced by the strain environment and the removal of …

The Electrical Properties Of Human Tissue For The Diagnosis And Treatment Of Melanoma Skin Cancer, Glenn Cameron Stante

Master's Theses

This thesis discusses the research, experimental methods, and data gathered for the investigation of a novel method for the diagnosis of melanoma skin cancer. First, a background about human skin tissue is presented. Then, a detailed description of melanoma along with current diagnosis techniques and treatment options are presented. In the experimental methods, the electrical properties of several types of tissue were analyzed, the purpose of which was to discover if a tissue type can be distinguished by its electrical properties alone. This would allow for the diagnosis of melanoma to be done by examining the electrical properties of the …

Mechanical Structures Resisting Anterior Instability In A Computational Glenohumeral Joint Model, Kevin Elmore

Theses and Dissertations

The glenohumeral joint is the most dislocated joint in the body due to the lack of bony constraints and dependence on soft tissue, primarily muscles and ligaments, to stabilize the joint. The goal of this study was to develop a computational model of the glenohumeral joint whereby joint behavior was dictated by articular contact, ligamentous constraints, muscle loading, and external perturbations. Validation of this computational model was achieved by comparing predicted results from the model to the results of a cadaveric experiment in which the relative contribution of muscles and ligaments to anterior joint stability was examined. The results showed …

Pegylation Of Niosomes, John A. Elliott

USF Tampa Graduate Theses and Dissertations

The research presented in this dissertation describes the creation and characterization of a novel antibody-vesicle conjugate modified with polyethylene glycol (PEG) that possesses enhanced binding to and uptake by inflammation-activated endothelial cells with improved storage stability and longer shelf-life and potential reduction in immunogenic potential compared to previous designs.

Targeted drug delivery provides an effective means of delivering therapeutic concentrations of a drug to the site or organ of action. The drug is delivered using a niosome, a vesicle with an aqueous core and a bilayer membrane composed of non-ionic surfactants and cholesterol. Antibodies that recognize specific cell antigens are …

A Rapid Prototyping Method For Constructing A Complex Three-Dimensional Substrate, Kathryn Jacoba Hart

Master's Theses

Cell culturing on three-dimensional structures has increased the possibilities in tissue engineering and bioreactor research. These structures enable cells to differentiate, proliferate, mobilize, and function in a conformation that more accurately mimics in vivo conditions. Computer generated models aid in development and rapid alteration of three-dimensional cell substrates, defining their internal structure as well as their external morphology. The rapid transition from substrate design to a viable culture is imperative to quickly advance research in biomedical and tissue engineering applications.

The aim of this thesis is to investigate the feasibility of a rapid prototyping process by selectively cross-linking and assembling …

The Design And Validation Of A Computational Rigid Body Model Of The Elbow., Edward Spratley

Theses and Dissertations

The use of computational modeling is an effective and inexpensive way to predict the response of complex systems to various perturbations. However, not until the early 1990s had this technology been used to predict the behavior of physiological systems, specifically the human skeletal system. To that end, a computational model of the human elbow joint was developed using computed topography (CT) scans of cadaveric donor tissue, as well as the commercially available software package SolidWorks™. The kinematic function of the joint model was then defined through 3D reconstructions of the osteoarticular surfaces and various soft-tissue constraints. The model was validated …

Improvement Of Eeg Based Brain Computer Interface By Application Of Tripolar Electrodes And Independent Component Analysis, Hongbao Cao

Doctoral Dissertations

For persons with severe disabilities, a brain computer interface (BCI) may be a viable means of communication, with scalp-recorded electroencephalogram (EEG) being the most common signal employed in the operation of a BCI. Various electrode configurations can be used for EEG recording, one of which was a set of concentric rings that was referred to as a Laplacian electrode. It has been shown that Lapalacian EEG could improve classification in EEG recognition, but the complete advantages of this configuration have not been established.

This project included two parts. First, a modeling study was performed using Independent Component Analysis (ICA) to …

Regression Analysis Of Fracture Toughness For Secondary Osteons Located In Human Cortical Bone, Chase A. Fetzer

Master's Theses

An experiment was carried out in order to locate and quantify osteon types within a sample of cortical bone taken from a human tibia. This was done using a microscope-camera assembly and the BioQuant computer software. The results of this were correlated with a previous experiment’s results on fracture toughness so that an analysis could be run on the data in order to determine the factors that most affect the value of fracture toughness of this cortical bone. Results were examined closely and the analysis repeated until the author was satisfied that the best possible model for fracture toughness had …

Muscular Properties And Balance Control In Older Adults, Christopher James Hasson

Open Access Dissertations

The goal of this dissertation was to understand the role of age-related changes in muscle mechanical properties in the control of upright posture in humans. First, a methodology for estimating subject-specific muscle properties in healthy young and older individuals was developed. Magnetic resonance and ultrasound imaging were used in conjunction with dynamometer experiments, musculoskeletal modeling, and numerical optimization to estimate the properties of the dorsiflexor and individual plantarflexor (gastrocnemius and soleus) muscles for 12 young and 12 older adults (balanced for gender). With aging there were declines in maximal isometric strength and increases in series-elastic stiffness in the male subjects, …

The Influence Of Work Of Fracture On Six Orthodontic Bonding Systems, Tyler S. Pritchard

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Bonding is the primary method of attaching brackets to teeth in modem orthodontics. Thus, many studies have focused on the maximum shear bond strength values of orthodontic adhesives. In contrast, very little research has been performed considering the work of fracture of orthodontic bonding systems. Work of Fracture is defined as the area under the curve of a stress-strain graph. Previous shear bond strength studies measured the force necessary to produce bond failure. The purpose of this study was to measure the maximum shear force and displacement of six bonding systems and to calculate the work of fracture.

Materials …

Assessment Of Electrospinning As An In-House Fabrication Technique For Blood Vessel Mimic Cellular Scaffolding, Colby M. James

Master's Theses

Intravascular devices, such as stents, must be rigorously tested before they can be approved by the FDA. This includes bench top in vitro testing to determine biocompatibility, and animal model testing to ensure safety and efficacy. As an intermediate step, a blood vessel mimic (BVM) testing method has been developed that mimics the three dimensional structure of blood vessels using a perfusion bioreactor system, human derived endothelial cells, and a biocompatible polymer scaffold used to support growth of the blood vessel cells. The focus of this thesis was to find an in-house fabrication method capable of making cellular scaffolding for …

A Pdms Sample Pretreatment Device For The Optimization Of Electrokinetic Manipulations Of Blood Serum, Timothy J. Abram

Master's Theses

This project encompasses the design of a pretreatment protocol for blood serum and adaption of that protocol to a microfluidic environment in order to optimize key sample characteristics, namely pH, conductivity, and viscosity, to enable on-chip electrokinetic separations. The two major parts of this project include (1) designing a pretreatment protocol to optimize key parameters of the sample solution within a target range and (2) designing /fabricating a microchip that will effectively combine the sample solution with the appropriate buffers to replicate the same bench-scale protocol on the micro-scale.

Biomarker detection in complex samples such as blood necessitates appropriate sample …

Development Of A Toolbox For The Kinematic Evaluation Of Hands-Up Video Games, Brooke Marie Odle

Theses

Children with cerebral palsy (CP) often have limited upper extremity (UE) control, Virtual reality (VR) is a current technology being evaluated as a form of UE therapy for children with CP, The systems currently available have been developed with games that cannot be graded to match the skill level of children with severely impaired UE control. A novel video game platform, "Hands-Up", has been developed at New Jersey Institute of Technology. The platform features software that allows for the customization of games and encourages users to make purposeful UE movements. To quantify changes and improvement in movement due to increased …

Preparation And Characterization Of An Electrospun Gelatin/Dendrimer Hybrid Nanofiber Dressing, Alicia P. Smith-Freshwater

Theses and Dissertations

A novel dendritic wound dressing was designed and characterized for its potential to treat chronic wounds. Comprised of gelatin, dendrimer, synthetic polymer and antibiotics, the dressing was electrospun to mimic the natural extracellular matrix (ECM). Gelatin is biocompatible, biodegradable, non-toxic, and easily available. The antibiotic, doxycycline, has the ability to inhibit matrix metalloproteinases. Matrix metalloproteinases, which occur in excess in chronic wounds, degrade the reconstituted ECM. Starburst™ polyamidoamine (PAMAM) dendrimer G3.5, which provides a versatile and structurally controlled architecture to construct nanomedicine, was covalently bonded to the gelatin backbone and electrospun into nanofibers with gelatin, doxycycline and stabilizing polymers. The …

The Use Of A Tri-Axial Accelerometer To Measure Changes In Lower Extremity Fatigue During Functional Activity, Kristin Morgan

Theses and Dissertations

In 2004, the National Collegiate Athletic Association reported ankle sprain as the most frequent injury in soccer, basketball, and volleyball players. Further research found an increased likelihood with fatigue. Measuring fatigue during functional activities has been a longstanding problem. In this study, changes in ankle biomechanics were measured using a tri-axial accelerometer embedded in the shoe as subjects (n=12) performed a fatiguing activity. Data were collected from the accelerometer and from established devices that are considered the industry gold standard. Several kinetic and kinematic accelerometer derived variables were highly correlated with these standards (r2>0.90) and were associated with changes …

Parametric Model Of Head Related Transfer Functions Based On Systematic Movements Of Poles And Zeros With Sound Location For Pole/Zero Models, Bahaa W. Al-Sheikh Hussein

Electronic Theses and Dissertations

Directional transfer functions (DTFs), the directional components of the Head Related Transfer Functions (HRTFs), are generally measured at finite locations in azimuth and elevation. Thus models are needed to synthesize DTFs at finer spatial resolution than the measured data to create complete virtual auditory displays. In this research, minimum-phase all-pole and all-zero models were used for modeling both human and cat DTFs. Real cepstrum analysis has been used to represent minimum phase HRTFs in the time domain. For the human DTFs, model orders were chosen to achieve specific objective error criteria published in previous studies that were based on subjective …

Creation Of Defined Single Cell Resolution Neuronal Circuits On Microelectrode Arrays, Russell Pirlo

All Dissertations

The way cell-cell organization of neuronal networks influences activity and facilitates function is not well understood. Microelectrode arrays (MEAs) and advancing cell patterning technologies have enabled access to and control of in vitro neuronal networks spawning much new research in neuroscience and neuroengineering. We propose that small, simple networks of neurons with defined circuitry may serve as valuable research models where every connection can be analyzed, controlled and manipulated.
Towards the goal of creating such neuronal networks we have applied microfabricated elastomeric membranes, surface modification and our unique laser cell patterning system to create defined neuronal circuits with single-cell precision …