Biomedical Engineering and Bioengineering Commons^™

A Study Of Acoustically Activated Nanodroplets, Songita Choudhury

Theses & Dissertations

Current treatment of acute myocardial infarction (AMI), which is the main pathophysiological event leading to death in the United States, has advanced considerably with the introduction of emergent percutaneous interventions, but there remains an urgent need for novel techniques to rapidly and accurately detect infarcted or ischemic tissue that results from AMI. Ultrasound contrast agents, also known as microbubbles (MB), have become commonplace in echocardiography. However, MBs are purely intravascular tracers and unable to cross endothelial barriers due to size. The limitations of MBs, namely size and short circulation times within the human body, led to the development of phase-change …

Verification And Validation Of Forces From Hippotherapy Rein Simulator, Sonia Sanchez

Graduate Theses - Biology & Biomedical Engineering

The thesis describes the redevelopment, testing, and validation of a rein training device intended to help riders learn to guide a horse during hippotherapy sessions. The thesis aims to validate and verify that the forces read by the redeveloped rein simulator were operant within ± 150 grams of the actual weight applied, as well as to investigate the effect of temperature on the system. The simulator focuses on the use of the English style of riding that uses direct force from the reins to guide a horse to turn or stop. Data was collected by hanging weights from the load …

Modeling Eeg And Tdcs In Scirun Software Packages, Aiden Keene, Aiden Thomas Keene

Senior Honors Projects

Never before has there been a greater emphasis on improving the shortcomings of treating mental health conditions. Our generation has more knowledge about technological practices with the potential to monitor and treat mental health symptoms than that of any generation before us. A breakthrough in this field made by CREmedical is called Tripolar Concentric Ring Electrodes (TCRE’s), which can measure signals from the brain more accurately than conventional electrodes. At CREmedical, TCREs are being used to study differences in electrical activity in the brain so as to identify abnormalities, and monitor responses to stimulation therapies. This semester I had the …

Effect Of Silk-Based Hydrogel Topography On Intestinal Epithelial Cell Morphology And Wound Healing In Vitro, Marisa E. Boch

University Scholar Projects

Recent advances in the field of biomaterials have suggested that cells cultured on substrates resembling the native tissue mechanical properties, matrix and growth factor composition, and topography can adopt phenotypes that more closely resemble the in vivo tissue compared to cells cultured on non-mimetic constructs. Understanding the effect of culture substrate on in vitro tissue formation is important for bioengineering applications that include mechanistic studies of healthy tissue function and development of disease models. In this work, Caco-2 adenocarcinoma cells were seeded on flat and crypt-like topographies of 3D-printed cytocompatible hydrogels derived from silk fibroin protein. Silk hydrogels were selected …

Extraction And Analysis Of Vector Flow Imaging Data In A Pediatric Population, Bailey Stinnett

Biomedical Engineering Undergraduate Honors Theses

Vector flow imaging (VFI) is a new ultrasound technology that provides real time, angle-independent visualization of flow velocities in the heart and great vessels. Thus far, VFI has been used for superficial applications due to the limited penetration depth of available transducer probes; however, this depth in smaller pediatric patients enables adequate aortic views. In this project, VFI was used to study pediatric aortic stenosis (PAS)—a congenital heart defect that results in the narrowing of the aorta and/or aortic valve. The decision to refer PAS patients for surgical or catheter-based intervention is initially based on Doppler ultrasound. VFI is potentially …

Effects Of Gsk101 Exposure On Astrocyte Mechanical Properties, Collagen Production, And Viability, Ethan Echols

Biomedical Engineering Undergraduate Honors Theses

Transient receptor potential vanilloid 4 (TRPV4) is a cation channel protein which is thought to facilitate extracellular matrix (ECM) modification and glial scar formation following traumatic brain injury (TBI). Activation of TRPV4 has been shown to correlate with an increase in intracellular Ca²⁺ concentration. TRPV4 is subject to both chemical and mechanical activation. This study involved chemical activation of TRPV4 in cultured mouse astrocytes using GSK101, the primary agonist of TRPV4, and subsequent evaluation of mechanical and chemical changes to the ECM. Prior to GSK101 exposure, the cells were seeded into Matrigel Matrix, a gelatinous protein mixture intended to …

3d Printed Force Transducers For In-Vitro Mitral Valve Chordae Tendineae Force Measurements, Hayley Chandler

Biomedical Engineering Undergraduate Honors Theses

Mitral valve surgery is incredibly prevalent in the United States with more than 40,000 mitral valve surgical procedures annually. Improving the imaging techniques used to diagnose these cases requires validation of 3D models through experimental data such as mechanical properties of the tissue. An essential part of this process for the mitral valve is measuring the force experienced by chordae tendineae. This has been achieved with brass force transducers but using a 3D printed design can have many benefits. In this study, 3D printed miniature c-shaped force transducers comparable to previous metal models were designed and created using Solidworks 2016. …

Investigation Of Functional Connectivity And Neurovascular Coupling In Different Vigilance / Breath-Hold States Of The Brain From Simultaneous Eeg-Fnirs Measurements, Olajide Babawale

Bioengineering Dissertations - Archive

Functional connectivity and neurovascular coupling are important phenomena that occur in the brain. Functional connectivity is the study of functional brain networks and their characteristics. While neurovascular coupling is the relationship or link between neuronal activity and corresponding cerebral blood flow in the brain. Up until now, both functional connectivity and neurovascular coupling have not been studied in different vigilance states of the brain from wakeful rest state to sleep state, using simultaneous EEG-fNIRS measurements. Also, the neurovascular coupling in different states of breath-holding has not been studied using simultaneous EEG-fNIRS measurements Therefore, my doctoral research utilized a whole-head simultaneous …

Creep Response And Adhesion Dynamics Of Glioblastoma Multiforme Cells During Migration In Confined Environment, Ishan Kamal Khan

Bioengineering Dissertations - Archive

Glioblastoma multiforme (GBM) is the most common and malignant form of primary brain tumor. One of the major challenges facing the treatment of GBM tumors is the detachment and subsequent migration of peripheral cells. Migration of GBM cells take place in mechanically distinct confined microenvironment along the borders of white matter tracts. Studies using microfluidic devices mimicking the in-vivo microenvironment have shown that the migration characteristics are significantly altered with the change in kinematic state of the migrating cell. Several studies on different types of cells have consistently shown that a cancerous cell is more compliant than a normal cell …

Investigation Of 1064-Nm Laser Fluence Within Tissue Phantoms And Its In Vivo Effects On Human Brain Networks, Hasan Parvez

Bioengineering Theses - Archive

For the past few decades there has been an increasing interest in the usage of near infrared (NIR) laser in the medical optics field. This is due to a number of studies conducted on different animal models utilizing NIR laser, which was reported to provide improvement in such cognitive functions as memory, decision making, and executive functions. The NIR laser produces no adverse effects in the human tissue, having a potential for treating different neurological disorders. However, there is limited knowledge related to the underlying mechanism of photon interaction with the human tissue. In this thesis, I tried to address …

Quantification Of Tumor-Associated Macrophages Following Immunomodulation Therapy In A Murine Allograft Model Of Colorectal Carcinoma, Caroline Spainhour

Biomedical Engineering Undergraduate Honors Theses

Colorectal Carcinoma (CRC) is one of the deadliest cancers in the world, with 150,000 new cases annually in the United States. Traditional treatments include chemotherapy and invasive surgery; however, research has shown that only 25% of patients that undergo traditional treatment have a positive result. Immunotherapy is an emerging form of cancer treatment that utilizes the patients’immune system to fight cancer cells by targeting inflammation, which plays a large role in the proliferation and metastasis of cancer cells.

Tumor-associated macrophages (TAMs) are immune cells that affect the inflammatory microenvironment of tumors. TAMs are M1 in the early stages of tumors, …

The Use Of Microfluidics And Dielectrophoresis For Separation, Concentration, And Identification Of Bacteria, Cynthia Hanson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Typical bacterial analysis involves culturing and visualizing colonies on an array of agar plates. The growth patterns and colors among the array are used to identify the bacteria. For fast growing bacteria such as Escherichia coli, analysis will take one to two days. However, slow growing bacteria such as mycobacteria can take weeks to identify. In addition, there are some species of bacteria that are viable but nonculturable. This lengthy analysis time is unacceptable for life-threatening infections and emergency situations. It is clear that to decrease the analysis of the bacteria, the culturing and growth steps must be avoided. …

Investigations Of Polyhydroxyalkanoate Secretion And Production Using Sustainable Carbon Sources, Chad L. Nielsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Polyhydroxyalkanoates (PHAs) are a type of biologically-produced plastic known for their biocompatibility and biodegradability. They have the potential to replace petroleum-based plastics as an environmentally-friendly alternative. This is beneficial because the release of plastics into environments such as the ocean and the buildup of plastics in landfills are major concerns facing society today. Currently, however, PHAs are significantly more expensive than their petroleum-based counterparts. This is largely due to the cost of carbon sources and of extracting the bioplastics from bacteria. The goal of these studies was to examine replacing traditional carbon sources used in PHA production like sugar and …

Role Of Local Renin-Angiotensin System In Altering Valve Interstitial Cell Phenotype, Sophia Scalise

Biomedical Engineering Undergraduate Honors Theses

Hypertension is a disorder prevalent in adults around the world and is a common attributable cause of heart disease and mortality [1]. Calcification is much more common in the aortic valve than the other three heart valves [2]. Aortic valve interstitial cells (VICs), the principal cell type found in the human aortic valve, have been linked to disease development when they change in phenotype to become osteoblast like cells [3]. The phenotypes of these cells play a role in the development of calcification in the aortic valves [4].

Angiotensin II is a hormone in the body that has been implicated …

Antibacterial Properties Of A Cationic Imidazolium-Containing Poly(Ionic Liquid), Kaitlyn P. Brickey

Biomedical Engineering Undergraduate Honors Theses

Poly(ionic liquids), or PILs, have been shown to have a number of biological applications as ligands, drug delivery vehicles, and nonviral DNA delivery mechanisms. Additionally, PILs have been proven to be efficient antibacterials. Imidazolium-containing PILs have promising results in antibacterial studies, but relating to their chain and charge density, only the effects of mono- & bis-imidazolium PILs have been sufficiently described in literature. The work detailed in this thesis aimed to further existing research on the effect of chain density by controlling the UV-initiator immobilization time. The effects of chain density were investigated by grafting poly(vinylimidazolium chloride) onto SiO_{2 …}

Structure And Property Of Polymers And Biopolymers From Molecular Dynamic Simulations, Xiaoquan Sun

Graduate Theses and Dissertations

Natural and synthetic polymers and biopolymers have been studied for a variety of applications in food emulsion, biopharmaceutical purification, tissue engineering, and biosensor. The structure and property of polymers and biopolymers are critically important to determine their functions. Molecular dynamics (MD) simulations have a unique advantage to explore the structure and property of polymers and biopolymers from the molecular level. In the dissertation, MD simulations were conducted to study the mechanisms of various biological and chemical processes controlled by polymers and biopolymers based on real-world experimental results.

Seven heptapeptides have been screened from a peptide library in our earlier study …

Novel Methodology For Emboli Analog Production And In-Vitro Simulation Of Acute Ischemic Stroke, Anne Preut

Graduate Theses and Dissertations

Stroke is the leading cause of disability and a primary cause of mortality, resulting in an estimated $33 billion dollars spent on healthcare, rehabilitation and lost productivity in the United States each year. The most prevalent cause of stroke incidents are acute ischemic events, manifested as blood clots in the vasculature supplying the brain. Current gold standard treatments have improved since 2006 with the introduction of mechanical stent retrievers; however, several issues with the current treatments to acute ischemic stroke remain. Thrombolysis of the clot with a tissue plasminogen activator may lead to weakening the vessel wall and consequently, hemorrhaging. …

The Effect Of Elastin Degradation On The Biomechanical Properties Of Porcine Aortic Tissue, Caleb Nissen

Biomedical Engineering Undergraduate Honors Theses

The rupture of abdominal aortic aneurysms (AAA) is currently the 13^th leading cause of death in the United States [1]. AAA is characterized, in part, by an increase in presence of proteolytic enzymes which degrade the structural proteins collagen and elastin [6]. The goal of this study was to examine the effect that elastin degradation has on the biomechanical properties of aortic tissue. For this experiment, porcine aortic tissue was cut in the circumferential and longitudinal directions. These specimens were exposed to an elastase solution for varying time-intervals and then underwent uniaxial tensile testing. Elastase-treated tissue tested in the …

In-Vitro Simulation Of Acute Ischemic Stroke, Paolo Garcia

Biomedical Engineering Undergraduate Honors Theses

Acute ischemic stroke (AIS) is a condition that involves the occlusion of a blood vessel within the brain, effectively preventing the passage of oxygen and nutrients. AIS is highly prevalent in the United States, where nearly 795,000 strokes happen per year and 87% of those are ischemic. From a medical standpoint, the obstructing clot can be removed with the use of a stroke retrieval device. However, a need arises for testing the aforementioned devices on a patient’s specific vascular geometries in order to increase the likelihood of a successful procedure. Outlined is a process for developing a physical simulation of …

Development Of An In Vitro Platform For The Exploration Of Skeletal Muscle Cell Mechanobiology, Sydney Spradlin

Biomedical Engineering Undergraduate Honors Theses

Muscles have the natural ability to regenerate when damaged. This works to keep the body functioning, unless this ability is overwhelmed. Volumetric muscle loss (VML) occurs when a substantial amount of a muscles mass is lost. This leads to the development of scar tissue, and often a loss of function. In order to find a solution for this condition, in vitro models are needed to explore the mechanobiology of skeletal muscle cells. Two platforms were developed in this study, to explore 3 factors: orientation, strain, and supporting structure. One platform used fibronectin stamped lanes on PDMS to encourage cell growth …