Engineering Commons^™

An In Vitro Model To Study The Role Of Iol: Lens Capsule Interactions In Posterior Capsule Opacification, Arjun Jaitli

Bioengineering Dissertations - Archive

Posterior capsule opacification (PCO) is the most common complication associated with intraocular lens (IOL) implantation. Unfortunately, current in vitro models cannot be used to assess the potential of PCO due to their failure to simulate posterior curvature of the lens capsule (LC), contradicting observations, different testing conditions and inherent challenges associated with use of human capsular bag models, cells and other tissue substrates. To overcome such a challenge, a new system to study IOL: LC interaction and potentially predict PCO was developed in this effort. It is believed that the interactions between an IOL and the lens capsule (LC) may …

Optimal Analytical Methods For High Accuracy Cardiac Disease Classification And Treatment Based On Ecg Data, Jianwei Zheng

Computational and Data Sciences (PhD) Dissertations

This work constitutes six projects. In the first project, a newly inaugurated research database for 12-lead electrocardiogram signals was created under the auspices of Chapman University and Shaoxing People's Hospital (Shaoxing Hospital Zhejiang University School of Medicine). This database aims to enable the scientific community in conducting new studies on arrhythmia and other cardiovascular conditions. In the second project, we created a new 12-lead ECG database under the auspices of Chapman University and Ningbo First Hospital of Zhejiang University that aims to provide high quality data enabling detection of the distinctions between idiopathic ventricular arrhythmia from right ventricular outflow tract …

Quantifying Mucosal Hemodynamics In A Murine Model Of Ulcerative Colitis With Diffuse Reflectance Spectroscopy, Elizabeth A. Bullard, Ariel I. Mundo, Shelby N. Bess, Kathryn P. Miller

Biomedical Engineering Undergraduate Honors Theses

Ulcerative colitis (UC) is a gastrointestinal, autoimmune disease that causes ulceration and inflammation of the colon with an incidence 10 out of every 100,000 people in North America and Western Europe. Though the exact etiology is uncertain, a number of studies have shown that inflammatory cells along with environmental factors, genetics, and lifestyle habits can contribute to the sustained inflammatory response. In order to determine the cellular mechanism behind relapse and remission of UC, researchers have frequently employed immunohistochemistry, western blotting and gene sequencing, but these destructive analysis methods require the removal of a sample, necessarily limiting these methods to …

Evaluating Cellular Response Of Different Valve Interstitial Cell (Vic) Phenotypes To Angiotensin I, Smit Patel

Biomedical Engineering Undergraduate Honors Theses

Calcific Aortic Valve Disease (CAVD), one of the leading causes of death in the United States, is characterized by diminished functioning and limited movement of the aortic valve (AV) due to increased thickening, disorganized extracellular matrix elastin fibers, increased collagen content, and abnormal deposition and formation of calcium nodules on the AV [1, 2]. There are two types of CAVD: i) Aortic valve sclerosis (AVS), in which patients suffer from tissue hardening, fibrosis, and early calcification, and ii) calcific aortic stenosis (CAS), representative by excessive calcification on the AV and reduced AV opening, are the two main forms of CAVD …

In Vivo Analysis Of A Proprietary Glass-Based Adhesive For Sternal Fixation And Stabilization Using Rabbit And Sheep Models, Cina Mehrvar, Emily Deignan, Mark Hurtig, Gideon Cohen, Paul Zalzal, Oleg Safir, Adel Alhalawani, Marcello Papini, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Wire cerclage remains the standard method of care for sternal fixation, following median sternotomy, despite being beset with complications. An emerging treatment option has been to augment the wires with an adhesive. A patented ionomeric glass (mole fraction: SiO₂:0.48, ZnO:0.36, CaO:0.12, SrO:0.04) has been used to formulate GPC+, a glass polyalkenoate cement (GPC), by mixing it with poly(acrylic) acid (PAA) and de-ionized water. In a human cadaver study, this material, when applied with wire cerclage, was able to significantly reduce sternal instability. However, the material has yet to be tested in pertinent animal models. Here, after a series …

Involvement Of The Ino80 Chromatin Remodeling Complex In Cell Division And Genomic Stability, Ethan Chen

Biomedical Engineering Undergraduate Honors Theses

Cell division is a vital biological process for growth and development in both single and multi-cellular organisms—whereby the cell must duplicate its organelles and genome in entirety and appropriately distribute the copied contents to the daughter cells. Cells undergo a cycle of two distinct phases: interphase and mitosis. During interphase, the cell replicates its genomic DNA (in the form of chromosomes) located within the nucleus. DNA replication is carried out in a euchromatin state, where the chromosome structure is loose and easily accessible by DNA polymerase and other replication enzymes. Upon the completion of replication, chromatin is condensed into highly …

Quantification Of Superoxide Production In Cells Treated With L-Buthionine Sulfoximine, Rebekah Townsley

Biomedical Engineering Undergraduate Honors Theses

Hydroxyl radicals, superoxides, and hydrogen peroxides are common reactive oxygen species (ROS) that are produced by the mitochondria during cellular respiration [1]. Signal transduction pathways in the mitochondria are used to maintain the balance of ROS. However, when these mechanisms fail to regulate ROS properly, it causes oxidative damage and can lead to the development of various diseases such as cancer, respiratory, neurodegenerative, and cardiovascular diseases. L-buthionine sulfoximine (BSO) has been used previously to induce oxidative stress by inhibiting the γ-GCS enzyme used to synthesize glutathione, an antioxidant used to convert ROS to water [3]. BSO reduces glutathione production, thus …

New Force Transducer For Mitral Valve Chordae Tendinea, Joseph Berryman

Biomedical Engineering Undergraduate Honors Theses

In order to inform the future of mitral valve repair and replacement, more investigation into the mechanics of the sub-valvular structure is needed. Understanding the roles of each chord during valve closure requires a sensor capable of detecting these small forces with enough sensitivity to determine the characteristics of each of the chordal types. The focus of the cantilever force transducer is to maximize this sensitivity while also minimizing the invasiveness of the sensor on the overall function of the chord. The design utilizes flexible yet strong 3D printed resin and cantilever arms to improve the strain exerted on a …

Use Of 3d-Printed Surgical Spoons Compared To Other Cystotomy Methods In Dogs, Davina D'Angelo

Animal Science Undergraduate Honors Theses

Bladder stones, also known as uroliths, are not an uncommon condition in domestic dogs. To remove these uroliths, which occur in various sizes, shapes, and compositions, veterinarians will perform a surgical procedure called a cystotomy. A cystotomy consists of creating a small incision into the lumen of the urinary bladder and the utilization of various methods to extract the uroliths. For general veterinary practitioners, the laparoscopic-assisted technique is unavailable. As a result, the methods available for urolith extraction are often limited to flushing the stones out by inserting a urinary catheter through the urinary tract and the use of off-label …

Computational Sentiment Analysis Of An Online Left Ventricular Assist Device Support Forum: Positivity Predominates, Melissa Austin, Abhiraj Saxena, Thomas O'Malley, Elizabeth Maynes, Henry Moncure, Nathan Ott, H. Todd Massey, Francesco Moscato, Antonio Loforte, John M Stulak, Vakhtang Tchantchaleishvili

Division of Cardiology Faculty Papers

Background: The impact of left ventricular assist device (LVAD) complications on the individual patient, overall sentiment, and its effect on referral patterns, is not fully understood. We sought to better understand patient attitudes towards LVAD therapy using a computational sentiment analysis approach.

Methods: Posts, comments, and titles were parsed from MyLVAD.com's HTML as a text file using custom Python scripts (version 3.6). Individual word frequency was computed with word classification as 'positive', 'negative', or 'neutral'. Data transformation and cleaning, sentiment determination, and analysis was performed with a binary dictionary package using R software (version 3.6).

Results: Sixty-six thousand eight hundred …

Photomodulatory Effects On Insulin Secreting Beta Cells, Sheccid Alejandra Loya

Bioengineering Theses - Archive

Diabetes mellitus is a chronic metabolic disease characterized by increased blood glucose levels and affects more than 8% of people worldwide (Rutter et. al, 2015). Typically, diabetes is divided into two large subcategories: type 1 diabetes (T1D) and type 2 diabetes (T2D). T1D is an autoimmune disorder caused by the attack of insulin secreting cells by t-cell mediated inflammatory response (Khrraoubi & Darwish, 2015). Currently, islet transplants offer a clinical treatment for restoration of glucose control. However, the current procedure may not be optimal as many transplanted islets do not survive because of the stresses induced during the process (Miki …

Isomotive Dielectrophoresis For Enhanced Analyses Of Cell Subpopulations., Mohamed Zakarya Rashed

Electronic Theses and Dissertations

As the relentless dream of creating a true lab-on-a-chip device is closer to realization than ever before, which will be enabled through efficient and reliable sample characterization systems. Dielectrophoresis (DEP) is a term used to describe the motion of dielectric particles/ cells, by means of a non-uniform electric field (AC or DC). Cells of different dielectric properties (i.e., size, interior properties, and membrane properties) will act differently under the influence of dielectrophoretic force. Therefore, DEP can be used as a powerful, robust, and flexible tool for cellular manipulation, separation, characterization, and patterning. However, most recent DEP applications focus on …

Development And Applications Of In-Vitro And In-Silico Models Of The Cardiovascular System To Study The Effects Of Mechanical Circulatory Support., Moustafa Meki

Electronic Theses and Dissertations

Cardiovascular diseases (CVDs) are the leading cause of mortality globally. With ongoing interest in CVDs treatment, preclinical models for drug/therapeutic development that allow for fast iterative research are needed. Owing to the inherent complexity of the cardiovascular system, current in-vitro models of the cardiovascular system fail to replicate many of the physiological aspects of the cardiovascular system. In this dissertation, the main concern is with heart failure (HF). In advanced HF, patients may receive Left Ventricular Assist Devices (LVADs) as a bridge to transplant or destination therapy. However, LVADs have many limitations, including inability to adapt to varying tissue demand …

Simulation Of Fracture Strength Improvements Of A Human Proximal Femur Using Finite Element Analysis., Waleed Ebraheem Alim

Electronic Theses and Dissertations

The most common hip fracture in the elderly occurs as a result of a fall to the side with impact over the greater trochanter resulting in a fracture of the proximal femur. The fracture usually involves the femoral neck or the intertrochanteric region. It has recently been determined that the fracture crack of a hip fracture typically initiates on the superior-lateral cortex of the femoral neck and then propagates across the femoral neck, resulting in a complete fracture. The strength of the superior-lateral cortex of the femoral neck is likely determined by the combined properties of the generally thin cortex …

Monitoring Fgf1-Treated Skin Wounds With Label-Free Multiphoton Microscopy, Gianna Busch

Biomedical Engineering Undergraduate Honors Theses

Chronic skin wounds pose a significant threat to public health, affecting as many as 5.5 million people in the United States every year and costing the healthcare system $10 billion annually^1,2. These wounds are associated with prolonged inflammation, poor vascularization, increased infection risk, and high mortality rates^3,4. There is significant interest in developing and testing a variety of biologics to promote wound healing. However, quantitative evaluations of healing are typically limited to measurements of wound size, and there is a critical need to develop quantitative biomarkers sensitive to different aspects of the healing process. Label-free multiphoton …

Mapping The Domain Of Rna Helicase Ddx1 That Interacts With The Ns1 Of Influenza A Viruses, Elise Wyatt

Biomedical Engineering Undergraduate Honors Theses

Of the known influenza virus strains, influenza A viruses (IAVs) are the most catastrophic due to their highly contagious nature and possibly life-threatening symptoms. IAVs invade a host cell and enter the nucleus where they use the cell’s nuclear machinery for replication of their viral RNA genome which is then exported to neighboring cells to establish a productive infection. Host pathogen recognition receptors (PRRs) respond to viral infection by signaling the cell to produce type I interferons (IFNs) to fight the foreign invader. Non-structural protein 1 (NS1) of IAVs, a major component in the regulation of viral replication, opposes host …

Developing Aligned Nerve Scaffolds In A 3d Type-I Collagen Gel, Gabriel David

Biomedical Engineering Undergraduate Honors Theses

Despite significant progress in the field of peripheral nerve repair, clinical success is still limited, leaving millions to suffer from peripheral neuropathy with billions spent every year for treatment. Nerve repair methods that are capable of maximizing the regenerative properties of peripheral nerves are greatly desired in the field of medical science. This research aims to fill the gap between modern methods and the future of nerve repair by creating type-I collagen scaffolds with aligned degradation pores that will assist and nurture nerves growing through them. This is achieved by incorporating adipose stem cells into type-I collagen hydrogels and aligning …

Statistical Machine Learning For Breast Cancer Detection With Terahertz Imaging, Tanny Andrea Chavez Esparza

Graduate Theses and Dissertations

Breast conserving surgery (BCS) is a common breast cancer treatment option, in which the cancerous tissue is excised while leaving most of the healthy breast tissue intact. The lack of in-situ margin evaluation unfortunately results in a re-excision rate of 20-30% for this type of procedure. This study aims to design statistical and machine learning segmentation algorithms for the detection of breast cancer in BCS by using terahertz (THz) imaging. Given the material characterization properties of the non-ionizing radiation in the THz range, we intend to employ the responses from the THz system to identify healthy and cancerous breast tissue …

Electroencephalography Resting-State Networks In People With Stroke, Dylan B. Snyder, Brian D. Schmit, Allison S. Hyngstrom, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Introduction

The purpose of this study was to characterize resting-state cortical networks in chronic stroke survivors using electroencephalography (EEG).

Methods

Electroencephalography data were collected from 14 chronic stroke and 11 neurologically intact participants while they were in a relaxed, resting state. EEG power was normalized to reduce bias and used as an indicator of network activity. Correlations of orthogonalized EEG activity were used as a measure of functional connectivity between cortical regions.

Results

We found reduced cortical activity and connectivity in the alpha (p < .05; p = .05) and beta (p < .05; p = .03) bands after stroke while connectivity …

Evaluating The Effects Of Wood Source On The Physicochemical Properties Of Crosslinked Cellulose Nanocrystals, Helena Tchoungang Nkeumen

Graduate Theses and Dissertations

Cellulose is an abundant and naturally occurring biopolymer that has been used by humans for food, shelter, and clothing for about two centuries now. Highly crystalline nanoparticles derived from cellulose, called cellulose nanocrystals (CNCs), show great potential to meet the rising need for sustainable and nontoxic materials for biomedical applications. However, multiple biomedical applications of CNCs, such as those involving their use in tissue engineering scaffolds, require CNC-based structures to be stable in aqueous environments, a property that native CNCs do not possess due to their inherent hydrophilicity. Chemical crosslinking of CNCs addresses this issue by providing aqueous stability to …

Design Of Control Logic And The Human-Machine Interface For A Demonstration Plant Growth Chamber Implemented On A Programmable Logic Controller, Rachael Koehler

Biological and Agricultural Engineering Undergraduate Honors Theses

This honors thesis covers the planning, development, and implementation of system controls and human-machine interface (HMI) for a demonstration plant growth chamber. The work is a continuation of an ongoing project to be used as an educational and recruiting tool manifesting the skills acquired from the Biological and Agricultural Engineering Department at the University of Arkansas’ College of Engineering. This work includes emergency controls, overall design interface, and controls for both the aeration and lighting subsystems of the growth chamber. Overall design interface controls established included development of two user modes, Administrator and Visitor. The Administrator user will have full …

Performance And Economics Of Solar Inverters And Module Level Power Electronics In A 1 Mw Photovoltaic System, Maxwell Criswell

Biological and Agricultural Engineering Undergraduate Honors Theses

Photovoltaic solar panels convert sunlight to electricity in the form of direct current; therefore, a necessary component of every photovoltaic system is an inverter to convert the electricity to usable alternating current. There are various commercially available inverter technologies manufactured today such as microinverters, string inverters, and central inverters, as well as module level power electronic devices such as DC optimizers that are capable of improving system performance in string and central inverter systems. This thesis compares the performance and economics of five different inverter and module level power electronic systems through model simulation using Helioscope software. The five alternatives …

Patient-Specific Finite Element Analysis For Mandibular Fracture Fixation, Ethan Snyder

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis proposes an approach for Finite Element Analysis (FEA) of mandibular fracture fixation. Using a Computerized Tomography (CT) scan of mandible obtained from a specific person, the material characteristics, density and modulus of elasticity, were determined from a set of discrete points within the mandible that are 1mm spaced based on the Hounsfield Units of these points. The mandible geometry was sectioned to simulate a fracture. Muscle and mastication forces were added to replicate post-surgery loading. Using a standard linear miniplate, this material model was compared with two commonly used mandibular cortical shell bone models: isotropic and orthotropic. A …

Photobiomodulation Of Neural Stem Cell Differentiation Using Infrared (810 Nm) Laser Stimulation, Noemi Salgado Cordova

Bioengineering Theses - Archive

The standardized clinical use of photobiomodulation (PBM) across many applications has been obstructed due to the lack of understanding in how each of the parameters affect the end results. Although the optimal parameters for the therapy have been estimated with a level of uncertainty, the positive effects have been documented on cell differentiation, wound healing, brain modulation, etc. These positive effects observed by PBM have been attributed to the increase in reactive oxygen species (ROS), nitric oxide (NO), and ATP along other molecules generated by the stimulation of Cytochrome-C Oxidase (CCO). Although there is much uncertainty surrounding the coupling mechanisms …

Exploring Imaging Technology In The Diagnosis And Treatment Of Pediatric Medically Refractory Epilepsy With Intracranial Electroencephalography And Post-Surgical Evaluations, Nasheha Baset

Bioengineering Theses - Archive

Abstract Exploring Imaging Technology in the Diagnosis and Treatment of Pediatric Medically Refractory Epilepsy with Intracranial Electroencephalography and Post-Surgical Evaluations Nasheha Baset, MS The University of Texas at Arlington, May 2021 Supervising Professor: Dr. Christos Papadelis Epilepsy is a disorder that commonly causes seizures due to abnormal neurological activity, which can disrupt daily life. Of all patients with epilepsy, 60% suffer from focal epilepsy. Approximately 15% of these cases are considered to be drug resistant, or refractory, as the patient is not responsive to a combination of two or more anti-epileptic drugs (AED). Traditionally, approaches to treatment of medically refractory …

Machine Learning Approaches For Lung Cancer Diagnosis., Ahmed Mahmoud Ahmed Shaffie

Electronic Theses and Dissertations

The enormity of changes and development in the field of medical imaging technology is hard to fathom, as it does not just represent the technique and process of constructing visual representations of the body from inside for medical analysis and to reveal the internal structure of different organs under the skin, but also it provides a noninvasive way for diagnosis of various disease and suggest an efficient ways to treat them. While data surrounding all of our lives are stored and collected to be ready for analysis by data scientists, medical images are considered a rich source that could provide …

Knee Angles After Crosstalk Correction With Principal Component Analysis In Gait And Cycling, Jordan Skaro, Scott J. Hazelwood, Stephen M. Klisch

Biomedical Engineering

Principal component analysis (PCA) has been used as a post-hoc method for reducing knee crosstalk errors during gait analysis. PCA minimizes correlations between flexion–extension (FE), abduction–adduction (AA), and internal–external rotation (IE) angles. However, previous studies have not considered PCA for exercises involving knee flexion angles that are greater than those typically experienced during gait. Thus, the goal of this study was to investigate using PCA to correct for crosstalk during one exercise (i.e., cycling) that involves relatively high flexion angles. Fifteen participants were tested in gait and cycling using a motion analysis system. Uncorrected FE, AA and IE angles were …

Immunomodulatory Biomaterials For Cancer Immunotherapy, Larry Donnell Stokes Jr

Honors Theses

Cancer immunotherapy has become an effective treatment in the toolbox of oncologists. Immunotherapy offers a less toxic alternative to standard cancer treatments such as chemotherapy and can have prolonged curative effects to decrease cancer recurrence. Today, many drugs and biological agents have been developed that target the immune system and elicit an antitumor/cancer response. These agents are known collectively as cancer immunotherapies. While immunotherapies have radically improved treatment outcomes for many cancer patients, there are drawbacks to using these treatments. Immunotherapy treatments have poor clinical responses in patients with tumors that lack immunogenicity. Some of the treatments also pose a …

Design Of An Undergraduate Laboratory Experiment Utilizing A Stirred-Tank, Jacketed Bioreactor, Brennen Middleton

Honors Theses

Bioreactors are utilized in many industries, such as the food, alternative fuel, and pharmaceutical industries, to design and manufacture products. Unlike the similar chemical batch reactors utilized in many chemical processing facilities, bioreactor utilization requires engineers to consider a wider range of operating conditions and parameters. This results in a more complex reaction system and controls network. Due to this, it is imperative for chemical and biomedical engineering students to not only understand the theory surrounding these reactor systems, but also understand how to properly design and perform operating procedures with these systems. Thus, it was determined to create an …

Design And Control Of A Peristaltic Pump To Simulate Left Atrial Pressure In A Conductive Silicone Model, Jeremy Collins

Mechanical Engineering Undergraduate Honors Theses

According to the CDC, atrial fibrillation is responsible for more than 454,000 hospitalizations and approximately 158,000 deaths per year. A common treatment for atrial fibrillation is catheter ablation, a process in which a long flexible tube is guided through the femoral artery and to the source of arrhythmia in the heart, where it measures the electrical potential at various locations and converts problematic heart tissue to scar tissue via ablation. This paper details the design and control of a low-cost ($400) peristaltic pump system using repetitive control to replicate blood pressure in the left atrium in a conductive silicone model …