Engineering Commons^™

Stress Relaxation In Orthodontic Aligner Plastics; An In Vitro Comparison Study, Kristopher J. Keller

Theses & Dissertations

The purpose of this study was to ascertain if repeated stresses from extension cycling would result in accumulated damage in aligner materials and affect force delivery. A secondary goal was to identify potential differences in mechanical behavior present among orthodontic aligner polymers. Four thermoplastic polymers (Essix ACE, Taglus, Zendura, and Zendura FLX) were thermoformed, cut into strips, and extension cycled to 0.4 millimeters in a 37C water bath. Force decay, maximum and minimum force, and elastic modulus were measured during cycling. Additional samples were subjected to controlled tension until failure, allowing the measurement of yield strength, ultimate strength, and elastic …

Atherosclerosis: Pathology, Role Of Sd-Ldl, Particle Size Characterization Of Sd-Ldl With Multiangle Light Scattering, Akshay Sudhakar Ukey

Masters Theses

Atherosclerosis is an inflammatory disease due to the accumulation of lipids in the inner wall of arteries. As per the report of Center of Diseases Control and Prevention (CDC), 1 in every 4 deaths is due to heart diseases each year. Atherosclerosis occurs when artery walls harden by the buildup of cholesterol, forming multiple atherosclerotic plaques within the aorta (4). Out of the modern medicines available to control cholesterol, statin is amongst the foremost widely used because it is both safe and effective in lowering high risk patients (9). However, usage of high statins dosage typically leads to some mild …

Understanding Radiation Resistance In Head And Neck Tumor Xenografts Using Diffuse Reflectance And Raman Spectroscopy, Sina Dadgar

Graduate Theses and Dissertations

Each year, 800,000 new patients are diagnosed with head and neck squamous cell carcinoma (HNSCC), a majority of whom are treated with a combination of daily fractions of radiation and weekly chemotherapy sessions for up to seven weeks. Current methods to evaluate treatment response of individual patients are limited to anatomical measurements of tumor burden using CT scan or MRI 4-8 weeks after completion of treatment. However, earlier knowledge of radiation-response prior to or at early days after commencement of therapy can aid oncologist with escalating and de-escalating treatment plans for exceptionally non-responding and responding patients. Such a knowledge can …

Assessment Of The Use Of Low Molecular Weight Diblock Copolymers For The Formation Of Stable, Tunable Droplet Interface Bilayers, Joseph Tawfik

Masters Theses

This thesis presents the use of diblock copolymers, poly(butadiene)-b-poly(ethylene oxide) (PB_m PEO_n) and poly(isoprene)-b-poly(ethylene oxide) (PI_mPEO_n), as amphiphilic molecular building blocks for the formation of synthetic polymer bilayer membranes using the droplet interface bilayer (DIB) technique. The DIB technique makes use of the self-assembly of amphiphilic macromolecules along oil-water droplet interfaces that can then be physically connected for the construction of liquid supported macromolecular bilayers at the droplet interface. These bilayer membranes are capable of hosting both naturally occurring and synthetic protein channels. This technique has been used to form synthetic bilayer membranes …

Docs_On_Blocks – A Defense In Depth Strategy For E-Healthcare, Saad Mohammed

Electronic Theses, Projects, and Dissertations

With the increase in the data breaches and cyber hacks, organizations have come to realize that cyber security alone would not help as the attacks are becoming more sophisticated and complex than ever. E-Healthcare industry has shown a promising improvement in terms of security over the past, but the threat remains. Thus, the E-Healthcare industries are aiming towards a Defense in Depth Strategy approach.

The project here describes how a Defense in Depth Strategy for E-Healthcare system can provide an environment for better security of the data and peer-to-peer interaction with stakeholders. The legacy systems have at some point failed …

Development Of A Pediatric Cardiac Assist Maglev Pump For Use With A Universal Driver System., Landon Heath Tompkins

Electronic Theses and Dissertations

Heart failure (HF) remains the leading cause of death, affecting 26 million adults worldwide and 6.5 million adults in the United States. Pediatric HF patients have been a historically underserved population with few options for mechanical circulatory support (MCS) therapy, a leading treatment as an alternative to heart transplantation. To address this clinical need, the Inspired Universal MagLev System is being developed; a low cost, universal magnetically levitated extracorporeal MCS system with interchangeable single-use pumps that will ultimately provide adult and pediatric patients ventricular and respiratory assist therapies. The Inspired Pediatric VAD is the first single-use pump application for this …

Technology Aiding In Neonatal Lung Developmental Care, Megan Kirk

Undergraduate Honors Theses

In this paper, old as well as new technological findings to decrease premature infant mortality are reviewed. This paper discusses fetal development throughout pregnancy from conception to full-term status as well as fetal lung development specifically from conception until full-term status. Several ideas to rapidly develop and mature fetal lungs are discussed such as mothers ingesting artificial surfactant supplements, either independently or coupled with antenatal corticosteroids, as well as intra-amniotic instillation prior to 28 weeks gestational. Drawbacks regarding these two are mentioned as well such as the fetus’s lungs not being mature enough to use the artificial surfactant leading into …

Validation Of Novel Obstructive Sleep Apnea Treatment With Silicone Gel Experimental Models, Dustin Walter Burd

UNLV Theses, Dissertations, Professional Papers, and Capstones

Predictive modeling to increase treatment success rates for surgical procedures is becoming more common in the scientific community. For obstructive sleep apnea (OSA), modeling has been predominately performed using computers as opposed to experimental models. Computer simulation saves time by eliminating the need to fabricate complex experimental models but comes at the expense of insight gained through physical observations made in real time. Experimental models for studying OSA are needed to validate computational work, provide perspective on anatomical scale and demonstrate complex deformations in real time. This work addresses prior hurdles in experimental model fabrication with a novel process using …

An Investigation On The Influences Of Radial Head Hemiarthroplasty Stem Fixation Techniques On Articular Mechanics, Jakub Szmit

Electronic Thesis and Dissertation Repository

Radial head hemiarthroplasty design has been extensively studied with a focus on utilizing the geometrical characteristics of the native radial dish as a guide of implant placement and design. Although implant design has been studied, optimal radial head implant fixation technique remains unknown. This thesis focused on the effect of stem fit on radiocapitellar contact mechanics, using both finite element and experimental bench-top approaches. Additionally, investigation into the impact of varus/valgus malalignment of the radial head in both the native state and following hemiarthroplasty was conducted. It was found that loose fitting a smooth stem axisymmetric radial head implant through …

Incorporation Of Lignin In Natural And Synthetic Biomaterials To Alter Mechanical And Biochemical Properties For Enhanced Wound Healing, Jorge Alfonso Belgodere

LSU Doctoral Dissertations

It is estimated that chronic, non-healing wounds affect more than 6.5 million Americans annually, with an estimated healthcare cost beyond $14 billion. Here, we attempted to create composites of natural (collagen type I or gelatin-methacrylate) or synthetic (poly(ethylene glycol) polymers incorporating a natural plant component, lignin, to combat the costs and limitations current wound healing methods face. Three-dimensional matrices of collagen type I (Col I) are widely used in tissue engineering applications for its abundance in many tissues, bioactivity with many cell types, and excellent biocompatibility. Inspired by the structural role of lignin in plant tissue, we found that sodium …

Development Of Water-Soluble Polyesters For Tissue Engineering Applications, Trent Gordon

Electronic Thesis and Dissertation Repository

The development of tunable polymers has become increasingly important for both tissue engineering and drug delivery. This thesis investigates the development of water-soluble polyesters that contain both natural and synthetic components. These polymers offer tunable chemical structures, as well as functional groups for the conjugation of crosslinking moieties or cell signaling molecules. The first series of polymers was synthesized from poly(ethylene glycol) (PEG) and aspartic acid (Asp) via a titanium catalyzed transesterification method to provide polymers with molar masses of 12 kg/mol. After deprotection, the pendent functional groups of Asp were reacted with methacrylic, maleic, and itaconic anhydride to introduce …

Navigation And Patient Specific Instrumentation In Shoulder Arthroplasty, Joseph Cavanagh

Electronic Thesis and Dissertation Repository

The humeral head osteotomy influences shoulder arthroplasty component height, version and neck shaft angle and therefore outcomes. The purpose of this study is to develop and utilize navigation to execute the osteotomy.

3D printed models were used to develop a navigation technique, and then to execute planned osteotomies. Free hand, fixed angle guide, patient specific guides, and real time navigation osteotomies were completed. The height, neck shaft angle and version were recorded. Also collected, were the planes of the guides once they were placed.

Navigation had significantly less error from the planned osteotomy in neck shaft angle versus all other …

Survey Of Airflow Around A Heated Manikin As A Simulated Aeromedical Evacuation Patient On A Litter With Computational Fluid Dynamics Models, George P. Lemmer

Theses and Dissertations

Aeromedical Evacuations remain the predominant method used to transport patients from forward deployed areas of operations to secure locations with more robust medical infrastructure. Transportation of chemical warfare casualties and infectious patients require additional attention to prevent cross contamination. Specific airflow characteristics paired with environmental control system settings are a gap in scholarly literature. Based on the available literature computational fluid dynamics models were created to simulate the airflow around a patient represented by human geometry using commercially available software. In order to compare simulated and experimental results a heated manikin was placed in the MURPHEE aerosol exposure chamber and …

Comparison Of Longitudinal Changes In Resting State Functional Magnetic Resonance Imaging Between Alzheimer’S And Healthy Controls, Berk Can Yilmaz

Theses

Resting State Functional Magnetic Resonance Imaging (rs-fMRI) is a technique that is widely used for analyzing brain function using different approaches and methods. This study involves rs-fMRI analysis of Blood Oxygenation Level Dependent (BOLD) signals acquired from Alzheimer’s disease (AD) Patients and Healthy Controls (HC). Each subject in the study had both functional and anatomical images with at least one rs-fMRI scan with their Anatomical (T1) scans. Previous rs-fMRI studies have demonstrated that AD shows differences in Amplitude of Low Frequency (<0.1 Hz) Fluctuations (ALFF), and Regional Homogeneity (ReHo) measures according to HCs.

The aim of the study is to investigate individual and group level differences using ReHo and mALFF related …

Pathophysiology And Proteogenomics Of Post-Infectious And Post-Hemorrhagic Hydrocephalus In Infants, Albert M. Isaacs

Arts & Sciences Electronic Theses and Dissertations

Post-infectious (PIH) and post-hemorrhagic (PHH) hydrocephalus occur as sequalae of neonatal sepsis or intraventricular hemorrhage (IVH) of prematurity, respectively. Together, PIH and PHH represent the most common form of infantile hydrocephalus, the most common indication for neurosurgery in children globally, and the leading cause of neurological morbidity and mortality worldwide. The lack of understanding of the pathophysiology of PIH and PHH, particularly with regards to the host central nervous system response to the antecedent infection and hemorrhage, perturbation of differentiating neural stems in the ventricular (VZ) and subventricular (SVZ) zones, and damage to periventricular white matter (PVWM) tracts carrying sensorimotor …

Effect Of Nanofiller Coating And Loading On Facial Elastomer Physical Properties, Rahmi K. Aulia

Theses & Dissertations

Current materials used for facial prostheses are far from being desirable, and improved properties with “skin-like” feel are needed. This study evaluates property changes induced by sequential additions of uncoated and hydrophobic-coated nano-SiO₂ to polydimethylsiloxane (PDMS) and compares them with those measured for conventional submicron SiO₂-filled materials. Each filler type was sequentially added to vinyl-terminated PDMS at 0%, 0.5%, 5%, 10%, and 15% by weight. Tensile, tear, Durometer hardness, translucency and viscoelastic properties were evaluated, with hardness and translucency also evaluated following 3000 hours of outdoor weathering. Results demonstrated that 15% coated nano-SiO₂-filled PDMS materials …

A Biomechanical Investigation Into The Effect Of Experimental Design On Wrist Biomechanics And Contact Mechanics, Clare E. Padmore

Electronic Thesis and Dissertation Repository

The wrist is one of the most commonly injured joints, and injury can have serious sequelae if pathological healing ensues. Strides have been made to understand normal and pathological wrist biomechanics using experimental approaches, which has contributed to improved patient care. The present work advances our understanding of the influence of experimental techniques and joint motion measurement techniques on in-vitro wrist biomechanical cadaveric studies, and applies the knowledge learned to a common clinical entity of scapholunate insufficiency.

First, the relative contributions of the carpal rows to wrist motion were assessed, in addition to the identification of limitations of current biomechanical …

Decellularization Of Porcine Cartilage Promotes Chondrogenic Differentiation Of Human Chondrocytes, Roxanne Nicole Stone

Boise State University Theses and Dissertations

Knee osteoarthritis (knee OA) is the most common type of osteoarthritis (OA) and accounts for 70% of arthritis-related hospital admissions and 23% of clinical visits. Major limitations in both the current non-surgical and surgical methods are that they only relieve pain and show no evidence for restoring natural tissue anatomy. Leaders in the field propose that a stem cell treatment approach holds promise for the regeneration of a greater proportion of hyaline-like tissue at the repair site. (Cross et al., 2014; Escobar Ivirico, Bhattacharjee, Kuyinu, Nair, & Laurencin, 2017; Helmick et al., 2008; Toh, Foldager, Pei, & Hui, 2014).

It …

Methods To Investigate Hyperthermia Induced By Tumor Treating Fields, Ruchi Singh

Dissertations & Theses (Open Access)

Tumor Treating Fields (TTFields) are an antineoplastic treatment delivered via application of alternating electric fields using insulated transducer arrays placed directly on the skin in the region surrounding the tumor. TTF’s is a non-invasive application of low-intensity (1-3 V/cm), intermediate-frequency (100-500 kHz) alternating electric fields. The predominant mechanism by which TTFields are thought to kill tumor cells is the disruption of mitosis through the depolymerization of microtubules and interruption of the spindle structure leading to mitotic catastrophe and the formation of non-viable daughter cells. Tumor Treating fields do not stimulate nerves and muscle because of their high frequency, and do …

A Core Reference Hierarchical Primitive Ontology For Electronic Medical Records Semantics Interoperability, Ziniya Zahedi

Engineering Management & Systems Engineering Theses & Dissertations

Currently, electronic medical records (EMR) cannot be exchanged among hospitals, clinics, laboratories, pharmacies, and insurance providers or made available to patients outside of local networks. Hospital, laboratory, pharmacy, and insurance provider legacy databases can share medical data within a respective network and limited data with patients. The lack of interoperability has its roots in the historical development of electronic medical records. Two issues contribute to interoperability failure. The first is that legacy medical record databases and expert systems were designed with semantics that support only internal information exchange. The second is ontological commitment to the semantics of a particular knowledge …

"A Comparison Of Variable Selection Methods Using Bootstrap Samples From Environmental Metal Mixture Data", Paul-Yvann Djamen

Mathematics & Statistics ETDs

In this thesis, I studied a newly developed variable selection method SODA, and three customarily used variable selection methods: LASSO, Elastic net, and Random forest for environmental mixture data. The motivating datasets have neuro-developmental status as responses and metal measurements and demographic variables as covariates. The challenges for variable selections include (1) many measured metal concentrations are highly correlated, (2) there are many possible ways of modeling interactions among the metals, (3) the relationships between the outcomes and explanatory variables are possibly nonlinear, (4) the signal to noise ratio in the real data may be low. To compare these methods …

Neuromotor Control Of The Hand During Smartphone Manipulation, Prasanna Kumar Acharya

LSU Doctoral Dissertations

The primary focus of this dissertation was to understand the motor control strategy used by our neuromuscular system for the multi-layered motor tasks involved during smartphone manipulation. To understand this control strategy, we recorded the kinematics and multi-muscle activation pattern of the right limb during smartphone manipulation, including grasping with/out tapping, movement conditions (MCOND), and arm heights.

In the first study (chapter 2), we examined the neuromuscular control strategy of the upper limb during grasping with/out tapping executed with a smartphone by evaluating muscle-activation patterns of the upper limb during different movement conditions (MCOND). There was a change in muscle …

Active Deep Learning Method To Automate Unbiased Stereology Cell Counting, Saeed Alahmari

USF Tampa Graduate Theses and Dissertations

Cell quantification in histopathology images plays a significant role in understanding and diagnosing diseases such as cancer and Alzheimers. The gold-standard for quantifying cells in tissue sections is the unbiased stereology approach. Unfortunately, in unbiased stereology current practices rely on a well-trained human to manually count hundreds of cells in microscopy images. However, this human-based manual approach is time-consuming, labor-intensive, subject to human errors, recognition bias, fatigue, variable training, poor reproducibility, and inter-observer error. Thus, the lack of high-throughput technology for automating unbiased stereology analyses remains a major obstacle to further progress in a wide range of neuroscience and cancer …

Metal Additive Manufacturing For Fixed Dental Prostheses, Mai El Najjar

Electronic Thesis and Dissertation Repository

The use of additive manufacturing (AM) in dentistry has gained momentum in recent years. However, high initial costs and uncertainty surrounding the quality of AM products are considered barriers to their use. This research compared dental substructures fabricated by AM versus conventional casting and milling.

Cobalt-chromium alloy rectangular bars and three-unit bridge substructures were fabricated by AM, casting or milling. Bars manufactured by AM exhibited superior flexural strength, shear bond strength of porcelain coating, and Vickers hardness. Bridge substructures fabricated by AM showed similar flexural stiffness to cast, similar flexural loads at failure to milled and cast, and overall accuracy …

Hyaluronic Acid Coated Targeted Lipid Micellar Nanoparticle As A Delivery Vehicle For Lapatinib And Ketoconazole In Egfr Mutated Lung Cancer, Nadia Tasnim Ahmed

USF Tampa Graduate Theses and Dissertations

Background: According to the American Cancer Society, lung cancer was accountable for over 142,000 deaths in the USA in 2019. Common mutations related to lung cancer mainly occur in TP53, EGFR, and KRAS genes. Lapatinib is a small molecule tyrosine kinase inhibitor which acts reversibly on both epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2). Overexpression of EGFR leads to increased production and signaling of proteins that cause upregulation of cellular proliferation, cholesterol synthesis and resistance to apoptosis. Ketoconazole is an imidazole antifungal agent which works principally by inhibiting the enzyme cytochrome P450 14α-demethylase (CYP51A1) …

Toward Precision Medicine With Nanopore Technology, Trang Andrea Vu

Theses and Dissertations

Currently, when patients are diagnosed with cancer, they often receive a treatment based on the type and stage of the tumor. However, different patients may respond to the same treatment differently, due to the variation in their genomic alteration profile. Thus, it is essential to understand the effect of genomic alterations on cancer drug efficiency and engineer devices to monitor these changes for therapeutic response prediction. Nanopore-based detection technology features devices containing a nanometer-scale pore embedded in a thin membrane that can be utilized for DNA sequencing, biosensing, and detection of biological or chemical modifications on single molecules. Overall, this …

Sol Retractor: Rapidly Deployable Film-Based C-Section Retractor, Casey Lee, Silas Cleveland, Jose Dolores Valdivieso, Joseph Perks

Honors Theses

Cesarean Sections (C-sections), a surgery conducted for baby delivery, can be divided into four distinct categories; Category 1 and 2 are considered emergency c-sections, and Category 3 and 4 are scheduled c-sections [2]. A comparative study from 2016 analyzed the difference of need for postoperative treatment between the Collins or the Alexis O retractor ( n = 100). The Alexis O C-Section retractor resulted in 19% of women requiring postoperative treatment, including medication, monitoring, and an extended stay at the hospital. The Collins resulted in 43% of the patients requiring postoperative treatment (p = 0.001) [5]. In emergency C-sections, surgical …

Nature-Inspired Electrode Materials For Next Generation Sustainable Energy Storage, Mikhail Miroshnikov

Dissertations, Theses, and Capstone Projects

Despite revolutionizing the world of portable electronics, the contemporary lithium-ion battery (LIB) suffers from challenges associated with the cost, safety, and environmental impact of transition metal oxide-based intercalation cathodes. To alleviate these issues, naturally occurring organic molecules may serve as sustainable alternatives to traditional inorganic cathode materials. The electrochemical properties of organic compounds are derived from redox-active functional groups containing oxygen, nitrogen and sulfur. Additionally, these functional groups are capable of coordinating metal ions beyond lithium, allowing for compatibility with sodium-ion batteries (SIBs) and other earth abundant metal-based energy storage systems. However, despite competitive performance against commercialized cathode materials, much …

Non-Invasive Peripheral Venous And Arterial Line Air Detector For Embolization Prevention, Alexandria Kwong, Kevin Shu, Dylan Meinster

Biomedical Engineering

The scope of this project includes designing a non-invasive bubble detector for peripheral venous and arterial lines. For minimally invasive cardiac procedures, arterial and venous access is necessary for these procedures as is constant flow through the tubing to prevent clotting and to administer drugs. Air bubbles are common in these lines and can be consequential if enough air is introduced into the human system. Air embolisms are the most common and relevant issues during these procedures. The goal of this device is to create an attachable detector for air bubbles in saline that can also terminate flow and alert …

Identification Of Patterns And Disruptions In Ambient Sensor Data From Private Homes, Yan Wang

USF Tampa Graduate Theses and Dissertations

The world’s population is rapidly aging and the increasing demand for home and health care services from this aging population brings unprecedented challenges to the economy and society. Ambient-assisted smart homes, residences equipped with ambient sensors to monitor the resident’s daily activities in a continuous and unobtrusive way, present great potential to manage the growing care service needs of this older population segment, and enable them to age-in-place.

Despite growing research, using ambient sensor data from private homes to monitor daily activities, health and wellness still faces significant challenges. To study ambient sensor data from private homes where annotated data …