Biomedical Engineering and Bioengineering Commons^™

Classifying And Predicting Walking Speed From Electroencephalography Data, Allen Rahrooh

Electronic Theses and Dissertations

Electroencephalography (EEG) non-invasively records electrocortical activity and can be used to understand how the brain functions to control movements and walking. Studies have shown that electrocortical dynamics are coupled with the gait cycle and change when walking at different speeds. Thus, EEG signals likely contain information regarding walking speed that could potentially be used to predict walking speed using just EEG signals recorded during walking. The purpose of this study was to determine whether walking speed could be predicted from EEG recorded as subjects walked on a treadmill with a range of speeds (0.5 m/s, 0.75 m/s, 1.0 m/s, 1.25 …

Investigating Virus Clearance Via Ph Inactivation During Biomanufacturing, Wenbo Xu

Biomedical Engineering Undergraduate Honors Theses

In the processing of biopharmaceuticals, viral clearance and viral safety are important for the development of monoclonal antibodies. Murine xenotropic leukemia virus (XMuLV) is one of the retroviruses, recommended by Food and Drug Administration (FDA) as a model virus for viral clearance via inactivation from therapeutics derived from Chinese hamster ovary cells (CHO). A robust and effective method was investigated to clear or inactivate endogenous viruses by low pH inactivation. The effects of different conductivity and inactivated time on XMuLV clearance was determined. Acetate buffer was prepared with different conductivity, and 2% XMuLV was spiked into acetate buffer. XMuLV virus …

Effect Of Polymer Composition Of Injectable Hydrogels On Programmable Release Of Methylene Blue, Mary Brandecker

Biomedical Engineering Undergraduate Honors Theses

Temperature sensitive hydrogels have been used as injectable hydrogels because the polymer solutions can be liquid at room temperature and gel at body temperature. Injectable hydrogels have been used in biomedical applications to deliver drugs and other small molecules throughout the body. Methylene Blue was used as the drug in this study for its antioxidant and neuroprotective properties. PluronicⓇ F127 (PF127) is a copolymer consisting of repeating units of polyethylene oxide and polypropylene oxide in the form PEO-PPO-PEO. PF127 in solution is a temperature sensitive hydrogel that transitions to a gel at body temperature at specific polymer compositions. A standard …

Phenotypic Characterization Of Differentiation Of Human Mesenchymal Stem Cells To Smooth Muscle Cells, Jackson Hedrick

Biomedical Engineering Undergraduate Honors Theses

Abdominal aortic aneurysms (AAAs) are expansions in the aortic wall with an increased tendency to rupture. These expansions are triggered by the breakdown of key aortic extracellular matrix (ECM) proteins—elastin and collagen. The degradation of aortic ECM proteins is the consequence of overexpressed matrix metalloproteases (MMPs)–MMP-2 and MMP-9. Adult vascular smooth muscle cells (SMCs) lack the ability to repair the elastic matrix assembly; thus, it is imperative to find a solution to both restore the imbalance of essential ECM proteins in the aorta and mitigate the effects of MMPs. Previous studies have revealed that bone marrow derived mesenchymal stem cells …

The 3d Scaffold Design Of De Novo Anterior Cruciate Ligament Graft, Dominique Angibeau

Honors Capstones

No abstract provided.

Seeing Eye To Eye: A Machine Learning Approach To Automated Saccade Analysis, Maigh Attre

Honors Scholar Theses

Abnormal ocular motility is a common manifestation of many underlying pathologies particularly those that are neurological. Dynamics of saccades, when the eye rapidly changes its point of fixation, have been characterized for many neurological disorders including concussions, traumatic brain injuries (TBI), and Parkinson’s disease. However, widespread saccade analysis for diagnostic and research purposes requires the recognition of certain eye movement parameters. Key information such as velocity and duration must be determined from data based on a wide set of patients’ characteristics that may range in eye shapes and iris, hair and skin pigmentation [36]. Previous work on saccade analysis has …

Stability Analysis Of A More General Class Of Systems With Delay-Dependent Coefficients, Chi Jin, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu

SIUE Faculty Research, Scholarship, and Creative Activity

This paper presents a systematic method to analyse the stability of systems with single delay in which the coefficient polynomials of the characteristic equation depend on the delay. Such systems often arise in, for example, life science and engineering systems. A method to analyze such systems was presented by Beretta and Kuang in a 2002 paper, but with some very restrictive assumptions. This work extends their results to the general case with the exception of some degenerate cases. It is found that a much richer behavior is possible when the restrictive assumptions are removed. The interval of interest for the …

Design Of Microporous Membranes For The Development Of Brain-On-Chip Devices, Andre Figueroa Milla

Biomedical Engineering Undergraduate Honors Theses

Traumatic brain injuries (TBIs) are a major global health concern that have an economic impact of $60 billion in the United States in related costs annually. Developing drugs for TBI treatment is an approach that currently faces limitations involving the permeability of the blood-brain barrier (BBB). The BBB naturally limits molecules from reaching the brain as a protective mechanism against disease, acting as a barrier during drug delivery. Understanding the BBB mechanically and chemically following a TBI could potentially assist future studies to alleviate the symptoms and long-term effects of TBI by pharmaceuticals. The Mechanobiology and Soft Materials Laboratory (MSML) …

A Bioinstrumentation Active Learning Educational Module: The Design Of A Working Temperature Sensor Using A Ntc Thermistor, Baylor Bush

Biomedical Engineering Undergraduate Honors Theses

The Department of Biomedical Engineering at the University of Arkansas has continued to develop over the years, with more students enrolling in the program each year. Within the first biomedical engineering course, Introduction to Biomedical Engineering, various topics are introduced to students, and the topic of bioinstrumentation has been one of the most complex and difficult topics for students to comprehend through just a few lectures. In order to aid students in grasping these intricate concepts, an active learning module was developed in which students can work in groups to build a simple thermistor circuit as a temperature sensor. The …

Comparing The Effects Of Fibroblast Growth Factors On Growth Rate Of Human Fibroblast Cell Lines, Tasha Repella

Biomedical Engineering Undergraduate Honors Theses

Numerous studies have demonstrated the usefulness of growth factors in medium formulations to promote proliferation and viability of human fibroblasts in laboratory settings. However, due to the differences in the source and age of fibroblasts, the ability of growth factors like hFGF1 to promote proliferation varies. Equally difficult is the ability of hFGF1 to promote proliferation of diseased fibroblasts due to complexities associated with specific mitochondrial diseases. In this context, we decided to evaluate the potential for novel hyper stable growth factors super hFGF and hFGF1 (shFGF and hFGF1 respectively), to contribute to proliferation of different normal and diseased fibroblasts. …

Development Of A Model For Accelerated Fatigue Testing In Venous Valves, Olga Brazhkina

Biomedical Engineering Undergraduate Honors Theses

Malfunctioning venous cause issues ranging from cosmetic to life threatening situations for millions of people in the U.S. (1). Venous valve bioprosthetics often fail due to a loss in leaflet tissue flexibility following chemical fixation of donor tissue (2). A viable solution for testing venous valves prior to and post chemical fixation is in high demand for the development of a more durable prosthetic replacement. As a result, this research aims to create a fatigue apparatus that provides a means to model the durability of venous valves. The design criteria for this project included modeling physiological conditions in an accelerated …

Modeling And Validation Of Tissue Optical Properties In The Photon Transport Regime, Katelyn Heath

Biomedical Engineering Undergraduate Honors Theses

Early detection of changes in epithelial cells, such as the development of neoplastic formations seen in epithelial dysplasia, can indicate regions of the epithelial tissue that are at a high risk for cancerous formation. Using concepts from diffuse reflectance spectroscopy, a Monte Carlo model was developed to predict the reflectance measured by a detector at a small source-detector separation on a microendoscope. The Monte Carlo results were then used to calculate a mathematical relationship between the reflectance and distance that can be used to determine optical properties in a tissue sample. This model was validated with liquid phantoms of specified …

Conceptualization And Fabrication Of A Bioinspired Mobile Robot Actuated By Shape Memory Alloy Springs, Lietsel Richardson

Electronic Theses and Dissertations

This work is an experimental study and fabrication of design concepts to validate the feasibility of smart materials and their applications in bio-inspired robotics. Shape-Memory Alloy (SMA) springs are selected as the smart material actuators of interest to achieve locomotion in the proposed mobile robot. Based on a previous design of the robot, this work focuses on both implementing a new locomotion concept and reducing size and weight of the previous design, both using SMA based actuators. Objectives are met in consideration of the conceptual mechanics of circular robot locomotion. The first prototype is a variation of the original design. …

Fluctuations In Walking Speeds And Spatiotemporal Gait Parameters When Walking On A Self-Paced Treadmill At Level, Incline, And Decline Slopes, Cesar Castano

Electronic Theses and Dissertations

On a daily basis, humans walk over a variety of terrains. Studies have shown that spatiotemporal gait parameters, such as stride length, stride frequency, stride variability, etc., change when humans walk down a decline and up an incline compared to level ground. However, these studies have been limited to using fixed speed treadmills or analyzing a small number of strides when conducted over ground. Thus, there is a need to investigate the fluctuations in spatiotemporal gait parameters of humans walking at their self-selected speed, which requires recording hundreds of strides. Here we hypothesized that subjects will walk with a slower …

Ecological Co2 Flux Of A Green Roof Ecosystem And A Typical Grassland Ecosystem, Madeline Oxner

Biological and Agricultural Engineering Undergraduate Honors Theses

The Hillside Auditorium Green Roof is a low impact development feature on the University of Arkansas campus. It retains storm water and allows plants living on the roof to take up and transpire the water. Green roofs work to mimic natural ecosystems in urban environments. A key property is ecosystem respiration, which plays a large role in the global carbon cycle and is an important biologic activity indicator. The ecosystem respiration of Hillside Auditorium Green Roof was compared to a typical grassland ecosystem at the University of Arkansas farm to determine how closely the green roof is able to mimic …

Hydrodeoxygenation Of Pinyon-Juniper Catalytic Pyrolysis Oil, Hossein Jahromi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Catalytic hydrodeoxygenation (HDO), is an effective process to convert oxygenated compounds to hydrocarbons. This process is widely used for improving the negative properties of biomass-derived pyrolysis oils (bio-oils) such as high acidity, poor stability, and low heating value. During this process oxygen is removed from the bio-oil in the form of water, thus the liquid product of HDO process consists of aqueous phase and hydrocarbon phase that can be easily separated. Synthesis of efficient HDO catalyst has been a major challenge in the field of bio-oil upgrading. Red mud, which is an alkaline waste from alumina industry was used to …

The Affective Perceptual Model: Enhancing Communication Quality For Persons With Pimd, Jadin Tredup

UNLV Theses, Dissertations, Professional Papers, and Capstones

Methods for prolonged compassionate care for persons with Profound Intellectual and Multiple Disabilities (PIMD) require a rotating cast of import people in the subjects life in order to facilitate interaction with the external environment. As subjects continue to age, dependency on these people increases with complexity of communications while the quality of communication decreases. It is theorized that a machine learning (ML) system could replicate the attuning process and replace these people to promote independence. This thesis extends this idea to develop a conceptual and formal model and system prototype.

The main contributions of this thesis are: (1) proposal of …

The Effects Of Bone Morphogenic Protein 2 On The Viability And Proliferation Of Dental Pulp Stem Cell Isolates, Joseph Cinelli

UNLV Theses, Dissertations, Professional Papers, and Capstones

Growth factor is an umbrella term used to describe a signaling molecule present in organisms that serves the purpose of influencing a stimulatory or inhibitory response from the target cell it acts on. Growth factors are categorized and classified by the types of tissues they act on and the cellular responses they illicit. For example, there are growth factors that act primarily in connective tissue on fibroblasts and they are aptly classified as the fibroblast growth factor family. Similarly, there is another family of growth factors that act on bone forming cells, among others, and they are known as bone …

Methods To Remotely Eliminate Biofilm From Medical Implants Using 2.4 Ghz Microwaves, Brett Glenn

Mechanical Engineering Undergraduate Honors Theses

Infections associated with biofilm growth are usually challenging to eradicate due to their high tolerance toward antibiotics [11, 12]. Biofilms often form on the inert surfaces of medically implanted devices [13]. No matter the sophistication, microbial infections can develop on all medical devices and tissue engineering constructs [12]. Related infections lead to 2 million cases annually in the U.S., costing the healthcare system over $5 billion in additional healthcare expenses [12].

Novel solutions to biofilm’s microbial colonization span the spectrum of engineering and science disciplines. Yet a practical solution still does not exist. The research presented here will explore a …

Assessing Commonly Used Methods In Measuring Yield Of Cellulose Nanocrystals, Marilyn Pharr

Biological and Agricultural Engineering Undergraduate Honors Theses

Cellulose is a ubiquitous, renewable biopolymer found in plants that can be broken down to isolate cellulose nanocrystals (CNCs). CNCs have been utilized in various applications that include biomedical technology, structural composites, and barrier films because of their unique mechanical, optical, and physicochemical properties. CNCs can be produced by a variety of approaches from cellulosic materials; however, strong acid hydrolysis is the most common and effective technique as it results in stable colloidal suspensions. Existing literature reveals a wide range of CNC yields, depending on the production process, raw material used, and the method of yield estimation. The yields of …

Molecular Investigation Of The Intestinal Barrier In Health And Disease, Santita Ebangwese

Renée Crown University Honors Thesis Projects - All

The intestinal epithelial barrier contributes to the absorption of nutrients and in maintaining homeostasis. Several intestinal disorders such as Crohn’s disease and Ulcerative Colitis show common pathological features corresponding to a decreased intestinal epithelial barrier function, which makes it imperative to investigate the functional units of the intestinal barriers formed by complex protein interfaces called the tight junctions. Among the diverse set of transmembrane proteins involved in the formation of tight junctions, the mal-distribution of claudin family of proteins show direct correlation to compromised barrier functioning. Interestingly, claudin-3 expression reduces drastically in compromised barriers, while an increased expression of claudin-23 …

Predictive Modeling Of Fate And Transport Of Three Prevalent Contaminants In Midwest Agroecosystem Surface Waters: Nitrate-N, Atrazine, And Escherichia Coli, Samuel Hansen

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The majority of streams and rivers in the United States (U.S.) are ecologically impaired, or threatened by anthropogenic stressors. Recent reports have found atrazine in drinking water to be associated with increased birth defects and incidences of Non-Hodgkin’s Lymphoma, with higher levels of significance from exposure to both atrazine and nitrate-N. In contrast, recent illnesses from E. coli contaminating vegetables that originated from irrigation water has increased awareness of identifying sources of E. coli entering irrigation reservoirs.

Methods to accurately predict atrazine and E. coli occurrence and potential sources in waterways continue to limit the identifying appropriate and effective prevention …

Bio-Desalination Of Brackish And Seawater Using Halophytic Algae, Endalkachew Sahle-Demessie, Ashraf Aly Hassan, Amro El Badawy

Department of Civil and Environmental Engineering: Faculty Publications

Global demand for water is rising. A sustainable and energy efficient approach is needed to desalinate brackish sources for agricultural and municipal water use. Genetic variation among two algae species, Scenedesmus species (S. sp.) and Chlorella vulgaris (C. vulgaris), in their tolerance and uptake of salt (NaCl) was examined for potential bio-desalination of brackish water. Salt-tolerant hyper-accumulators were evaluated in a batch photobioreactors over salinity concentration ranging from 2 g/L to 20 g/L and different nutrient composition for their growth rate and salt-uptake. During algae growth phase, the doubling time varied between 0.63 and 1.81 days for S …

Designing An In Vitro Mitral Valve Mounting And Testing System For Micro Ct Imaging, Marinna Tadros

Biomedical Engineering Undergraduate Honors Theses

Five million people in the US are diagnosed with valvular disease, of which mitral valve disease is one of the most common. Computational models are informed by high resolution images and have the potential to aid in diagnosing and establishing surgical plans to treat mitral valve diseases. Existing methods using 7T MRI imaging have limitations such as small bore diameter, long imaging times and difficulty in maintaining trans-mitral fluid pressure throughout the scan. Imaging with Micro CT allows for efficient scan times and eliminates bore size constraints which allows for imaging more sizes and types of MVs. There is a …

Vector Flow Imaging In Pediatric Cardiology - Extracting And Validating Data, Mason Belue

Biomedical Engineering Undergraduate Honors Theses

In the field of bedside cardiac diagnostic imaging, Doppler Ultrasound (DU) is the gold standard for diagnosing heart conditions. The largest benefit of DU is its ability to noninvasively image cardiac flow and allow the estimation of blood velocity and quantification of anatomical disease. However, to get correct velocity estimation, the position of the transducer in relation to the flow field needs to be known. This is the problem of angle/direction dependency and limits DUs accuracy when imaging in areas where perfect alignment or exact position of the transducer in relation to flow field is not possible or known, such …

Autofluorescence To Study The Effects Of Acid Concentration On Cellular Metabolism In Vitro, Robin L. Raley

Chemistry & Biochemistry Undergraduate Honors Theses

Ultraviolet (UV) radiation-induced sunburns and their accompanying afflictions are a growing public health concern in the United States. There is a need for techniques that can accurately and non-invasively characterize the physiology of sunburned skin tissue directly after UV-damage and applying a topical skin treatment to relieve pain and promote healing. Two-photon excited fluorescence (TPEF) microscopy and fluorescence lifetime imaging (FLIM) can be used to investigate metabolic processes in live cells through endogenous fluorescence of the cofactors, NADH and FAD. These methods employ the optical redox ratio of FAD/(NADH+FAD), mean NADH lifetime, and the separation of the free and bound …

On-Demand Label Production, Robert A. Zimmerman

Master's Theses

The production and approval process for the various labels used in clinical trials wastes significant time and resources through the need to outsource label production or rely on large reams of pre-cut label stock for each revision throughout the process. An in-house, on-demand label printing and cutting system is a potential remedy to this waste. Previous work by Cheadle et al. resulted in a functional electomechanical prototype of the label cutting aspect of this research, capable of rudimentary linear cuts. In this continued research, emphasis was placed on improved label cutting capabilities and creating PC control software for label design. …

The Role Of Gene Expression Noise In Mammalian Cell Survival, Kevin Farquhar

Dissertations and Theses (Open Access)

Drug resistance and metastasis remain obstacles to effective cancer treatment. A major challenge contributing to this problem is cellular heterogeneity. Even in the same environment, cells with identical genomes can display cell-to-cell differences in gene expression, also known as gene expression noise. Gene expression noise can vary in magnitude in a population or in fluctuation time scales, which is influenced by gene regulatory networks.

Currently, it is unclear how gene expression noise from gene regulatory networks contributes to drug survival outcomes in mammalian cells. An isogenic cell line with a noise-modulating genetic system tuned to the same mean is required. …

Effects Of Ambient And Laser Light On Water Evaporation From The Surface Of Polyurethane Swabs Doped With Surfactant, Collin Campbell

Chemical Engineering Undergraduate Honors Theses

Polyurethane swabs are a common instrument for environmental sampling in the food, medical, and forensic fields due to their high recovery of organisms like viruses, spores, and bacteria. For sampling microbes in food and medical facilities, storage of the collected samples occurs under the absence of light to promote growth for more accurate testing. In the forensic fields, microbial growth results in sample contamination so the inhibition of this growth requires the drying of the swabs. This work studies the evaporation rates of water from polyurethane swabs under zero watt incident light, 30 W fluorescent bulb, 50 mW 532 nm …

Hrv - Ecg Generator: Software For Testing Heart Rate Variability Detection, Matthew Joseph Pogorelec

Theses and Dissertations

Heart rate variability (HRV) has been shown to serve as an effective diagnostic and prognostic tool in a variety of clinical applications, including for patients who have suffered from myocardial infarction, sepsis and liver cirrhosis. There currently exist a variety of devices and software to quantify HRV based on RR interval series collected from ECG data. However, as the uses for HRV expand, a greater variety of devices for different applications are being designed and developed. Thus, it is useful to have available a method for efficiently testing preliminary software. The HRV/ECG Generator software is designed to build both an …