Biomedical Engineering and Bioengineering Commons^™

Biomechanical Characterization Of Video-Recorded Short-Distance Falls Involving Children Equipped With A Biometric Device In A Childcare Setting: A Pilot Study., Danielle K. Cory

Electronic Theses and Dissertations

Background: A fall is the most common falsely reported injury scenario when a young child presents for medical care and the caregiver is concealing abuse. There is a lack of reliably witnessed falls with known outcomes to aid in the distinction between accidental and abusive injuries.

Objectives: The objectives of this study were to characterize video-recorded short distance falls involving young children in a childcare setting, to identify body regions most commonly impacted in these short distance falls, to characterize the head biomechanics of these falls, and describe fall characteristics. Additionally, physics-based models were used to predict fall biomechanics in …

Cardiovascular Intelligence: Novel Quantitative Cardiology, Deep Learning And Machine Learning Models To Predict Clinical Outcomes, Vignesh Balasubramanian

Theses and Dissertations

Arterial compliance has been recognized as a critical parameter in governing pulsatile flow dynamics. It has traditionally been assumed constant throughout the cardiac cycle. Its computation has been based either on the classic Windkessel model in diastole or the stroke volume over pulse pressure method in systole. We proposed a novel compliance-pressure loop (CPP loop) approach to quantify arterial compliance and compare it to existing linear and nonlinear methods. This was followed by an analysis of increased pulse wave reflections in hypertension due to impedance mismatching and how the effective energy transmission to the vasculature is compromised. Their quantification in …

Bioink Optimization And Effects Of Microgravity On 3d Bioprinted Cell Laden Constructs, Likitha Somasekhar

Theses and Dissertations

Bioengineered 3D tissue constructs have gained attention as in vitro tools for the study of cell-cell and cell-matrix interactions and are being explored for potential use as experimental models for mimicking human tissues. One of the main problems in tissue engineering is the necessity to vascularize complex engineered tissues and sacrificial printing has been recognized as a possible solution to vascularization of the bioprinted tissues. Research studies have demonstrated that exposure to microgravity in space induces adaptive alterations in vascular structure and function. Changes in the morphology and gene expression is observed when endothelial cells are exposed to microgravity and …

Evaluation Of Visible Diffuse Reflectance Spectroscopy In Liver Tissue: Validation Of Tissue Saturations Using Extracorporeal Circulation, Stylianos Voulgarelis, Faraneh Fathi, Astrid G. Stucke, Kevin D. Daley, Joohyun Kim, Michael W. Zimmerman, Johhny C. Hong, Nicholas Starkey, Kenneth P. Allen, Bing Yu

Biomedical Engineering Faculty Research and Publications

Significance: Real-time information about oxygen delivery to the hepatic graft is important to direct care and diagnose vascular compromise in the immediate post-transplant period.

Aim: The current study was designed to determine the utility of visible diffuse reflectance spectroscopy (vis-DRS) for measuring liver tissue saturation in vivo.

Approach: A custom-built vis-DRS probe was calibrated using phantoms with hemoglobin (Hb) and polystyrene microspheres. Ex vivo (extracorporeal circulation) and in vivo protocols were used in a swine model (n=15) with validation via blood gas analysis.

Results: In vivo absorption and scattering measured by vis-DRS with and without biliverdin …

Analyzing The Effects Of E-Hook Peptides On Kinesin-1, Ashton Ward Murrah, Baylee Hope Howard

Honors Theses

Cancer is the second leading cause of death in the United States. Cancerous growth is a result of oncogenes, or mutated genes that increase the rate of cell division in an uncontrolled manner. Cell division, which consists of mitosis and cytokinesis phases, is dependent upon the active movement of kinesin motor proteins along microtubules to rearrange the cytoskeleton for equitable distribution of genetic material to daughter cells. As kinesins are vital to this process, if we could prevent kinesin from binding to the microtubules, cell division would cease.

The goal of this study is to develop a method to prevent …

Improving The Efficacy Of Epinephrine Delivery For Anaphylaxis Through Development Of A Novel Auto-Injector Device And Increased User Education, Jennifer Ansley Myers

Honors Theses

Anaphylaxis is a life-threatening condition caused by the body’s overreaction to a certain allergen. The most widely accepted treatment for this condition is immediate administration of epinephrine, a hormone secreted by the adrenal glands that initiates the body’s fight or flight response, through an intramuscular injection. In most cases, patients that experience anaphylaxis are prescribed an epinephrine auto-injector to carry with them at all times which contains a single dose of epinephrine. Though these devices have been widely accepted for many years, there are many problems caused by their design and the lack of training that their users receive. The …

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 …

Development Of Quantitative Ultrasound-Mediated Molecular Imaging Of The Tumor Microenvironment, Trevor Mitcham

Dissertations and Theses (Open Access)

While conventional diagnostic imaging modalities provide anatomical information to clinicians, these techniques are not sensitive to critical physiological processes. In order to properly classify cancer, it is necessary to investigate noninvasive methods which can provide insight into these processes, allowing clinicians to determine personalized therapeutic options. Therefore, molecular imaging is focused on visualization and characterization of biomarkers within the tumor microenvironment (TME), which can then be combined with the anatomical information provided from diagnostic imaging.

Two such biomarkers of interest are blood oxygen saturation (SO₂) and cell receptor expression. SO₂ is a measure of the fraction of …

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 …

Oxone® Mediated Tempo-Oxidized Cellulose Nanomaterials: Material Characterization, Ultrafiltration Membrane Separations, And Thin Film Composite Gas Transport Analysis, John Phillips Moore

Graduate Theses and Dissertations

Cellulose nanomaterials (CNMs) are derived from plant matter and are comprised of nanoscopic cellulose crystals and fibers. They have a diverse set of applications, from cosmetics to oil recovery. This study focuses on the properties of Oxone® mediated TEMPO-oxidized cellulose nanomaterials (OTO-CNMs) and their use in controlling the transport properties of polymeric substrates. Synthesis and characterization of cellulosic nanoparticles have resulted in the creation of OTO-CNMs with properties that increase hydrophilicity. With added hydrophilicity, OTO-CNMs possess lower fouling propensity, making them ideal membrane additive for transport limited separations such as hemodialysis.

To utilize the material and unique properties thereof, this …

Peptoid-Based Microsphere Coatings For Biomaterial Applications, Jesse Leland Roberts

Graduate Theses and Dissertations

Peptoids are peptidomimetic oligomers that predominantly harness similarities to peptides for biomimetic functionality. The incorporation of chiral, aromatic side chains in the peptoid sequence allows for the formation of distinct secondary structures and self-assembly into supramolecular assemblies, including microspheres. Peptoid microspheres can be coated onto substrates for potential use in biosensor technologies, tissue engineering platforms, and drug-delivery systems. They have the potential for use in biomedical applications due to their resistance to proteolytic degradation and low immunogenicity. This dissertation focuses on the physical characteristics and robustness of the peptoid microsphere coatings in various physiological conditions, along with their ability to …

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 …

Electroactive Polymeric Composites To Mimic The Electromechanical Properties Of Myocardium In Cardiac Tissue Repair, Kaylee Meyers, Bruce Lee, Rupak Rajachar

Michigan Tech Publications, Part 1

Due to the limited regenerative capabilities of cardiomyocytes, incidents of myocardial infarction can cause permanent damage to native myocardium through the formation of acellular, non-conductive scar tissue during wound repair. The generation of scar tissue in the myocardium compromises the biomechanical and electrical properties of the heart which can lead to further cardiac problems including heart failure. Currently, patients suffering from cardiac failure due to scarring undergo transplantation but limited donor availability and complications (i.e., rejection or infectious pathogens) exclude many individuals from successful transplant. Polymeric tissue engineering scaffolds provide an alternative approach to restore normal myocardium structure and function …

Development Of An Intraperitoneal Catheter Placement Device For Use On The Battlefield, Riley Reynolds

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The objective of this project was to simplify peritoneal cavity access so an Airforce field medic can safely infuse oxygen microbubbles (OMBs) into the intraperitoneal space for the emergency treatment of hypoxia due to lung damage. To solve this problem, we created an intraperitoneal catheter placement device for use on the battlefield. The three common methods and some of the most common devices for peritoneal cavity access were reviewed. Injury frequencies for each of the three methods were analyzed. The results showed that each of the access techniques gives a similar rate of iatrogenic injury.

The battlefield conditions where the …

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 …

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 …

Quantifying The Effect Of Intrinsic Aging On Skin Microstructure And Mechanical Function Using Multiphoton Microscopy, Alan Edward Woessner

Graduate Theses and Dissertations

Over the next couple of decades, the number of elderly individuals is expected to double, bringing increased healthcare spending due to seemingly minor injuries to skin. In skin, the 3D dermal collagen fiber network, which is the primary load-bearing structure, undergoes changes in organization and composition due to intrinsic aging. However, the relationships between altered microstructure and mechanical function is not well understood. Quantitative imaging techniques have been used in the past to link skin structure to mechanical function, but previous analysis has been limited to 2D assessments. Multiphoton microscopy (MPM) is a non-destructive imaging technique with intrinsic depth-sectioning capabilities, …

A Comparative Study To Assess The Osteogenic Potential Of Competing Bioceramics For Bone Tissue Engineering, Nashaita Patrawalla

Theses and Dissertations

Biomimetic composite scaffolds comprising of bioactive ceramic-based materials incorporated within a polymeric framework have shown considerable promise for use in bone tissue engineering (BTE) applications. Although bioceramics have shown immense promise for use in BTE, few studies have performed a head-to-head comparison of the osteogenic properties of the most promising bioceramic materials. The goal of this study was to compare three different bioceramics – Bioglass 45S5 (BG), Laponite XLG (LAP), and β-Tricalcium Phosphate (TCP) – on the physical properties (i.e., swelling, stability, compressive modulus, bone bioactivity) of methacrylated collagen (CMA) hydrogels and osteogenic differentiation of human MSCs (hMSCs) encapsulated within …

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 …