Biomedical Engineering and Bioengineering Commons^™

Shape Memory Behavior Of Dense And Porous Niti Alloys Fabricated By Selective Laser Melting, Soheil Saedi

Theses and Dissertations--Mechanical and Aerospace Engineering

Selective Laser Melting (SLM) of Additive Manufacturing is an attractive fabrication method that employs CAD data to selectively melt the metal powder layer by layer via a laser beam and produce a 3D part. This method not only opens a new window in overcoming traditional NiTi fabrication problems but also for producing porous or complex shaped structures. The combination of SLM fabrication advantages with the unique properties of NiTi alloys, such as shape memory effect, superelasticity, high ductility, work output, corrosion, biocompatibility, etc. makes SLM NiTi alloys extremely promising for numerous applications.

The SLM process parameters such as laser power, …

Oxygen Transport In Carotid And Stented Coronary Arteries, Eoin A. Murphy

Doctoral

Oxygen deficiency, known as hypoxia, in arterial walls has been linked to increased intimal hyperplasia, which is the main adverse biological process causing in-stent restenosis. Stent implantation can have significant effects on the oxygen transport into the arterial wall. Helical flow has been theorised to improve the local haemodynamics and the oxygen transport within stented arteries. In this study an advanced oxygen transport model was developed to assess different stent designs. This advanced oxygen transport model incorporates both the free and bound oxygen contained in blood and includes a shear-dependent dispersion coefficient for red blood cells. In two test cases …

Atherosclerotic Plaque Adhesion Strength And Its Role In Plaque Rupture, Bilal Merei

Theses and Dissertations

Cardiovascular diseases are disorders affecting the blood vessels and the heart. According to the World Health Organization, cardiovascular diseases are one of the leading causes of death worldwide. They are responsible for over 17.1 million deaths per year worldwide, representing 31.5% of deaths 1, 2. Atherosclerosis, a chronic inflammatory disorder affecting large arteries, is the underlying cause of many cardiovascular diseases. Plaque rupture is a serious complication of advanced atherosclerosis, often leading to life-threatening clinical consequences such as myocardial infarction (heart attack) or stroke. 75% of newly developed myocardial infarction cases are caused by atherosclerotic plaque rupture. It affects approximately …

The Viability Of Advantg Deterministic Method For Synthetic Radiography Generation, Andrew Albert Bingham

Masters Theses

"Time sensitive and high resolution image simulations are needed for synthetic radiography generation. The standard stochastic approach requires lengthy run times with poor statistics at higher resolutions. The investigation of the viability of a deterministic approach to synthetic radiography image generation was explored. The aim was to analyze a computational time decrease over the stochastic method. ADVANTG was compared to MCNP in multiple scenarios including a Benchtop CT prototype, to simulate high resolution radiography images. By using ADVANTG deterministic code to simulate radiography images the computational time was found to decrease over 10 times compared to the MCNP stochastic approach"--Abstract, …

Combination Of Bmp-2 And Relaxin To Induce Osteogenesis In Vivo, Sahitya Injamuri

Masters Theses

"Bone grafts are a common procedure for treating craniofacial injuries such as trauma, surgery, and reconstruction. Autografts and allografts have limitations which encourages the use of synthetic bone grafts. While synthetic bone grafts, such as hydroxyapatite (HA) microspheres, are advantageous for their cost and reproducibility, they lack the cells and growth factors needed for proper osteoinduction. Bone morphogenetic protein-2 (BMP-2) has been shown to increase the osteoinduction of grafts but the effective dose is above physiological levels and causes undesired effects on the body. Relaxin has been shown to enhance BMP-2's ability to induce bone formation in vitro and thus …

3d Bioprinting A Pcl/13-93b3 Glass Composite And Its Potential Use As A Bio-Ink, Caroline Blair Murphy

Masters Theses

"A major limitation of using synthetic scaffolds in tissue engineering is little growth of incorporated cells in the interior of the scaffold, resulting in insufficient angiogenesis in the scaffold interior. Recently, cells have been 3D bioprinted concurrently with biomaterials to produce a cellularized, bioactive, angiogenic 3D environment. This thesis describes a novel solvent-extrusion method for printing polycaprolactone (PCL)/bioactive borate glass composite as a biomaterial for a cell-laden scaffold.

Bioactive borate glass was added to a mixture of PCL and organic solvent to make an extrudable paste, creating scaffolds measuring 10×10×1 mm³ in overall dimensions with pore sizes ranging from …

Computational Studies On Biomechanics Of Concussion And On Efficacy Of Football Helmets, David Labyak

Dissertations, Master's Theses and Master's Reports

Football helmets have been used for many years to prevent head injuries to players. Over the years, the helmet design has evolved from a crude leather head covering to the more recent form fitting helmets that are seen today. The one design feature that has been common in the majority of all helmets is a hard polycarbonate shell with a foam cushion padding. The main goal of the padding layer was to reduce the amount of linear acceleration during an impact event. The one feature that has been overlooked is how stiff the padding is in rotation.

The purpose of …

Design Of Robust Hydrogel Based On Mussel-Inspired Chemistry, Yuan Liu

Dissertations, Master's Theses and Master's Reports

The structure of catechol is found in mussel adhesive proteins and contributed to both wet-resistant adhesion and cohesive curing of these proteins. A synthetic nano-silicate, Laponite was incorporated into catechol-containing hydrogels and the hydrogel network-bound catechol formed strong reversible interfacial interaction with Laponite. The contribution of incorporated catechol-Laponite reversible interfacial interactions to the mechanics of hydrogels constructed by different strategies was studied. In the first strategy, Laponite and catechol were introduced into the double network hydrogel (DN) via the free radical co-polymerization of a catechol-containing monomer, backbone monomer, and crosslinker. The introduction of catechol-Laponite interactions significantly improved the compressive strength …

Formulation And Testing Of Biodegradable Polymeric Coating On Zinc Wires In Cardiovascular Stent Application, Avishan Arab Shomali

Dissertations, Master's Theses and Master's Reports

Biodegradable and biocompatible poly (L-lactic-acid) (PLLA) coating was applied on a modified zinc (Zn) substrate by dip coating, with the intent to delay the bio-corrosion and slow the degradation rate of zinc substrate. 3-(Trimethoxysilyl) propyl methacrylate (MPS) was used for modification of the zinc substrate for promoting the adhesion between the metallic substrate and the polymer coating. It is hypothesized that the delay in Zn biodegradation could be useful in the first several weeks to prevent the early loss of mechanical integrity of the endovascular stent and to improve the healing process of the diseased vascular site. The PLLA coating …

The Impact Of Active Aerodynamics On Motorcycles Using Computational Fluid Dynamics Simulations, Aditya Sripathi

All Graduate Theses, Dissertations, and Other Capstone Projects

Motorcycles are mostly utilized by commuters whose requirements are cheap and affordable transportation from point A to point B. Motorcycles also provide means to tour various places and have a leisure time for the majority of motorcyclists. Unfortunately, with pros also come cons such as accidents which are disabling or life-taking. According to motorcycle crash statistics produced every year, the majority of motorcycle crashes are caused due to facing unexpected obstacles in the path causing collisions due to insufficient braking time. Thus, this thesis serves as a mean to overcome this issue and provide a technological solution to the world …

Limb Stabilization In Older Adults And Chronic Stroke Survivors: A Pilot Study, Raymond C. Doudlah, Robert A. Scheidt, Aaron J. Suminski

Biomedical Engineering Faculty Research and Publications

Visual fidelity influences many aspects of daily living, including stabilizing wrist movements against environmental perturbations. Here, we present a pilot investigation to determine how visual feedback impacts wrist stabilization for populations with age related declines in motor function and chronic stroke. To quantify these interactions, behavioral performance and local brain activation were observed during a task requiring stabilization of the wrist against constant and stochastic extensor torque perturbations. All subjects were better able to stabilize their wrist when veridical visual feedback of their limb was provided. Examination of the neural activation maps in the Control and Aging populations revealed patterns …

Lung Injury Pathways: Adenosine Receptor 2b Signaling Limits Development Of Ischemic Bronchiolitis Obliterans Organizing Pneumonia, John C. Densmore, Terry R. Schaid, Paul M. Jeziorczak, Meetha Medhora, Said H. Audi, Shraddha Nayak, John Auchampach, Melinda R. Dwinell, Aron M. Geurts, Elizabeth R. Jacobs

Biomedical Engineering Faculty Research and Publications

Purpose/Aim of the Study: Adenosine signaling was studied in bronchiolitis obliterans organizing pneumonia (BOOP) resulting from unilateral lung ischemia. Materials and Methods: Ischemia was achieved by either left main pulmonary artery or complete hilar ligation. Sprague–Dawley (SD) rats, Dahl salt sensitive (SS) rats and SS mutant rat strains containing a mutation in the A_2B adenosine receptor gene (Adora2b) were studied. Adenosine concentrations were measured in bronchoalveolar lavage (BAL) by HPLC. A_2A (A_2AAR) and A_2B adenosine receptor (A_2BAR) mRNA and protein were quantified. Results: Twenty-four hours after unilateral PA …

Analytical-Based Methodologies To Examine In Vitro Nanokinetics Of Silver Nanoparticles, Sesha Lakshmi Arathi Paluri

Browse all Theses and Dissertations

Advancements in the nanotechnology have taken a huge leap in 21st century resulting in 1814 consumer products containing nanomaterials. About 47% of these products belong to the health and fitness sector and ~24% utilize silver nanoparticles (AgNPs). Despite the promising biomedical applications of AgNPs (e.g. bone cements, contrasting agents, and drug-carriers), lack of standardized methods for examining their nanokinetics (i.e., Absorption, Distribution, Metabolism, and Elimination (ADMEs)) limit their clinical implementation. The current work addresses this knowledge gap by developing analytical-based approaches for studying in vitro ADMEs of AgNPs. To demonstrate the versatility of these methodologies, two in vitro kidney study …

Dysregulation Of Phospholipase D (Pld) Isoforms Increases Breast Cancer Cell Invasion, Kristen Fite

Browse all Theses and Dissertations

Breast cancer remains the second most prevalent cancer among women in the U.S. with metastatic breast cancer having the worst prognosis. A rapidly proliferating tumor under various stressors will promote phenotypic cellular changes, known as epithelial-to-mesenchymal transition (EMT), which allows cells to begin to invade surrounding tissue, enter the circulatory system, and eventually seed a distant metastatic site. The phospholipase D (PLD) enzymes are critical regulators of cell signaling pathways necessary for cell migration. While the importance of PLD enzymes in cancer cell invasion is well known, clinically applicable methods of PLD inhibition are not yet available. The best-studied isoforms …

The Analysis Of Pediatric Sleep Lab Inefficiencies, Jessica Buehler, Autumn Barkley, Caitlin Dickerson, Andrew Fosnight, Omar Saad

Williams Honors College, Honors Research Projects

The goal of this project is to develop a children’s sleep apnea test for home use. This design is to be of cost and quality improvement to what is currently on the market. It is important to fully understand the background of this sleep disorder in order to create this improvement. Knowing what sleep apnea is, as well as the different types, is what is used to create the methods such as S.C.O.P.E.R. Each letter is used to observe one portion or aspect of the human body and how it functions with regards to sleep apnea. The data taken from …

Local Probability Based Transformations And Diagonal Projection: A New Support Vector Machine-Like Method For Classification Of Feature Vectors, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

No abstract provided.

Characterization Of Polyurethane For Use As Substrate In Nanofiber Sensor For Biomedical Applications, Megan Theaker

Williams Honors College, Honors Research Projects

The purpose of this project is to begin to determine properties of polymer nanocomposites that make a suitable substrate for nanofiber sensors. In this work, sensitivity of a sodium ion selective sensor constructed with polyurethane was used as a benchmark for comparison with sensors constructed with nylon-6. The sensors were characterized using contact angle and chronoamperometry. Using an ANOVA analysis, the results showed that the multi-walled carbon nanotube type was a significant factor on sensor response both with and without additional functionalization of the polymer by calixarene. The weight percentage of polyurethane in the electrospinning solution was also statistically significant …

Meta-Analysis Of Studies On Cpr: A Better Route To New Practice Guidelines, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

Quantitative synthesis of research results multiple small clinical trials using the statistical techniques of meta-analysis yields conclusions in excellent agreement with large randomized “mega-trails”. The present paper introduces a simple yet powerful method of meta-analysis for combining results of any published studies of a proposed treatment compared with a suitable control. These may include pre-clinical or clinical models generating either continuous or dichotomous data.

Increased Risk Of Children For Subtle Closed Head Injury From Soccer Heading, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

No abstract provided.

Valveless Pumping: The Reflected Pulse Wave Hypothesis, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

No abstract provided.