Biomedical Engineering and Bioengineering Commons^™

Investigation Of A Simulated Annealing Cooling Schedule Used To Optimize The Estimation Of The Fiber Diameter Distribution In A Peripheral Nerve Trunk, Arya Vigeh

Master's Theses

In previous studies it was determined that the fiber diameter distribution in a peripheral nerve could be estimated by a simulation technique known as group delay. These results could be further improved using a combinatorial optimization algorithm called simulated annealing. This paper explores the structure and behavior of simulated annealing for the application of optimizing the group delay estimated fiber diameter distribution. Specifically, a set of parameters known as the cooling schedule is investigated to determine its effectiveness in the optimization process.

Simulated annealing is a technique for finding the global minimum (or maximum) of a cost function which may …

Characterization Of Potential Health Promoting Lipids In The Co-Products Of De-Flossed Milkweed, Vicki Schlegel, Richard Zbasnik, Tammy Gries, Bo Hyun Lee, Timothy Carr, Ji-Young Lee, Curtis Weller, Susan Cuppett

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The floss and oil of the common milkweed (Asclepias syriaca L.) seeds are currently used to produce comforters/pillows and skin care products, respectively. As an outcome of these products, copious quantities co-products (pressed seed meal and pod biomass) are disposed of each year despite the presence of potential health benefiting lipids. The objective of this project was to determine the feasibility of developing the lipid fraction from of these co-products for the fast growing dietary human health market. Although certain types of lipids were affected by the extraction solvent used (hexane and diethyl ether) as were overall amounts, analysis …

Evaluation Of Delivery Conditions For Cutaneous Plasmid Electrotransfer Using A Multielectrode Array, Bernadette Ferraro, Loree C. Heller, Yolmari L. Cruz, Siqi Guo, Amy Donate, Richard Heller

Bioelectrics Publications

Electroporation (EP) is a simple in vivo method to deliver normally impermeable molecules, such as plasmid DNA, to a variety of tissues. Delivery of plasmid DNA by EP to a large surface area is not practical because the distance between the electrode pairs, and therefore the applied voltage, must be increased to effectively permeabilize the cell membrane. The design of the multielectrode array (MEA) incorporates multiple electrode pairs at a fixed distance to allow for delivery of plasmid DNA to the skin, potentially reducing the sensation associated with in vivo EP. In this report, we evaluate the effects of field …

Vascular Smooth Muscle Cells In Response To Gold Nanoparticles, William Mcallister

All Theses

In this master's thesis we look at elucidating the interactions between nanoparticles and cells. Specifically, we looked at how the cell mechanics are affected, cytotoxicity of the nanoparticles, and shifts in cell phenotypes. There has been much research looking into whether nanoparticles are cytotoxic, but limited amounts looking at their effect on mechanics especially with vascular smooth muscle cells. This cell type has two distinct phenotypes of synthetic and contractile that each serve different purposes physiologically.
The first experiments we did were cytotoxicity assays to see if the cells could survive the treatment with nanoparticles. If the cells died within …

A Rapid And Computationally Inexpensive Method To Virtually Implant Current And Next-Generation Stents Into Subject-Specific Computational Fluid Dynamics Models, Timothy J. Gundert, Shawn C. Shadden, Andrew R. Williams, Bon-Kwon Koo, Jeffrey A. Feinstein, John F. Ladisa

Biomedical Engineering Faculty Research and Publications

Computational modeling is often used to quantify hemodynamic alterations induced by stenting, but frequently uses simplified device or vascular representations. Based on a series of Boolean operations, we developed an efficient and robust method for assessing the influence of current and next-generation stents on local hemodynamics and vascular biomechanics quantified by computational fluid dynamics. Stent designs were parameterized to allow easy control over design features including the number, width and circumferential or longitudinal spacing of struts, as well as the implantation diameter and overall length. The approach allowed stents to be automatically regenerated for rapid analysis of the contribution of …

What Is Inverse-Geometry Ct?, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Inverse-geometry computed tomography (IGCT) systems are being developed to provide improved volumetric imaging. In conventional multislice CT systems, x-rays are emitted from a small area and irradiate a large-area detector. In an IGCT system, x-ray sources are distributed over a large area, with each beam irradiating a small-area detector. Therefore, in the inverse geometry, a series of narrow x-ray beams are switched on and off while the gantry rotates. In conventional CT geometry, cone-beam and scatter artifacts increase with the imaged volume thickness. An inverse geometry may be less susceptible to scatter effects, because only a fraction of the field …

Salen Mn Complexes Mitigate Radiation Injury In Normal Tissues, Rosalind A. Rosenthal, Brian Fish, Richard P. Hill, Karl D. Huffman, Zelmira Lazarova, Javed Mahmood, Meetha Medhora, Robert C. Molthen, John E. Moulder, Stephen T. Sonis, Philip J. Tofilon, Susan R. Doctrow

Biomedical Engineering Faculty Research and Publications

Salen Mn complexes, including EUK-134, EUK-189 and a newer cyclized analog EUK-207, are synthetic SOD/catalase mimetics that have beneficial effects in many models of oxidative stress. As oxidative stress is implicated in some forms of delayed radiation injury, we are investigating whether these compounds can mitigate injury to normal tissues caused by ionizing radiation. This review describes some of this research, focusing on several tissues of therapeutic interest, namely kidney, lung, skin, and oral mucosa. These studies have demonstrated suppression of delayed radiation injury in animals treated with EUK-189 and/or EUK-207. While an antioxidant mechanism of action is postulated, it …

Biokinetic Mechanisms Linked With Musculoskeletal Health Disparities: Stochastic Models Applying Tikhonov's Theorem To Biomolecule Homeostasis., Asit K. Saha, Yu Liang, Sean S. Kohles

Mechanical and Materials Engineering Faculty Publications and Presentations

Multiscale technology and advanced mathematical models have been developed to control and characterize physicochemical interactions, respectively, enhancing cellular and molecular engineering progress. Ongoing tissue engineering development studies have provided experimental input for biokinetic models examining the influence of static or dynamic mechanical stimuli (Saha, A. K., and Kohles, S. S., 2010, “A Distinct Catabolic to Anabolic Threshold Due to Single-Cell Nanomechanical Stimulation in a Cartilage Biokinetics Model,” J. Nanotechnol. Eng. Med., 1(3) p. 031005; 2010, “Periodic Nanomechanical Stimulation in a Biokinetics Model Identifying Anabolic and Catabolic Pathways Associated With Cartilage Matrix Homeostasis,” J. Nanotechnol. Eng. Med., 1(4), p. 041001). In …

Novel Nanofiber Structures And Advanced Tissue Engineering Applications, Vince Beachley

All Dissertations

Extracellular matrix (ECM) nanofibers such as collagen and elastin make up an important component of natural tissues. These structural components serve to impart mechanical strength and provide locations for cell attachment and biomolecule storage. Cells respond to their structural environment in a wide variety of ways beyond physical support, and it has been demonstrated that this environment directly modulates cell behaviors such as, morphology, differentiation, ECM production, attachment, and migration. ECM nanofibers also play an important role as a template for tissue formation during development, remodeling, and regeneration. Nanofiber based tissue engineering strategies aim to mimic the geometry of the …

Methods Development And Force Field Evaluation For Molecular Simulations Of Interactions Between Structured Peptides And Functionalized Material Surfaces, Galen Collier

All Dissertations

The process of protein adsorption to material surfaces is highly complex and it is one of the most fundamental concepts upon which progress in the field of bioengineering is based. The strategic design of material surfaces for optimal utility in specific biological environments is absolutely dependent upon a thorough understanding of the mechanisms underlying protein adsorption, yet there is still a very limited understanding of these mechanisms. The primary reason for this lack of understanding is that protein adsorption is a dynamic process which occurs at the atomic and macromolecular scale, where experimental analyses provide a view that is static …

Algal Biofilm Production And Harvesting System For Wastewater Treatment With Biofuels By-Products, Logan Christenson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Excess nitrogen and phosphorus in discharged wastewaters can lead to downstream eutrophication, ecosystem damage, and impaired water quality that may affect human health. Chemical-based and physical-based technologies are available to remove these nutrients; however, they often consume significant amounts of energy and chemicals, greatly increasing treatment costs. Algae are capable of removing these pollutants through biomass assimilation, and if harvested, can be utilized as a feedstock for biomethane or biodiesel production. Currently, difficulties in harvesting, concentrating, and dewatering algae have limited the development of an economically feasible treatment and production process. When algae are grown as surface-attached biofilms, the biomass …

Fluoro-Silane As A Functional Monomer For Protein Conformational Imprinting, Yun Peng

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

By using the technology of molecularly imprinted polymer (MIP), we propose to synthesize a protein conformational imprint that also acts as a plastic enzyme, inducing protein structural transitions. The imprint aims at MIP-induced stabilization and / or formation of bound protein secondary structure and the applications associated with analysis and correction of misfolded proteins. The screening of polymeric functional monomers being able to induce the conformational transitions in proteins is investigated in this report.

The fluoro-silanes (3-heptafluoroisopropoxy)propalethoxysilane (7F) and 3,3,3-trifluoropropylmethoxysilane (3F) were employed as functional monomers for synthesis of this catalytic protein conformational imprint via sol-gel reactions. 3F was demonstrated …

Characterization And Application Of Dynamic In Vitro Models Of Human Airway, Hemangkumar J. Patel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent years, respiratory diseases have emerged as a leading cause of mortality across the globe. In the United States alone respiratory diseases are the fourth leading cause of deaths annually. Moreover, with the rapid increase of industrialization and urbanization, the occurrences of respiratory diseases are expected to remain high with strong chances of increasing in the future. To ameliorate the epidemic of respiratory disease, it is first important to understand its underlying mechanisms.

Respiratory research studies in animals have elucidated the chronological order of the pathological events and systemic responses inside the lung, but understanding the response of individual …

A Study On The Applications And Toxicity Assessments Of Carbon Nanotubes In Tissue Engineering, Rena Baktur

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Carbon nanotubes (CNTs) are one of the most popular nanomaterials. There has been increasing interest in the development and applications of carbon nanotubes due to their huge potential in industrial and medical applications. Recent applications of carbon nanotubes include development of scaffolds and drug delivery systems. Despite rapidly emerging applications of CNTs, little is known about the impact of CNTs on cellular processes, especially mesenchymal stem cell (MSC)'s differentiation. Also, the effects of nanoparticle exposure under different conditions on cellular responses have not been well characterized yet.

To characterize the effects of CNTs on creating nanoscale scaffolds for tissue engineering, …

Design And Implementation Of An Eye Blink Controlled Human Computer Interface, Poonam Gwalani

Theses and Dissertations

Advances in Human Computer Interface (HCI) have made this area of research important for improving the standard of living for people with disabilities. An eye blink system is presented to allow people with disabilities to control a standard computer mouse. This system is designed for people who are paralytic with no control over their arms, speech, and anyone who is restricted to only the control of eye and head movements. This system is based on infrared reflectivity to capture and analyze real time eye blink signal of the user. It uses simple economical hardware electronics to emulate the functionality of …

3d Functional Modeling Of Dbs Efficacy And Development Of Analytical Tools To Explore Functional Stn, Deepak Kumbhare

Theses and Dissertations

Introduction: Exploring the brain for optimal locations for deep brain stimulation (DBS) therapy is a challenging task, which can be facilitated by analysis of DBS efficacy in a large number of patients with Parkinson’s disease (PD). The Unified Parkinson's Disease Rating Scale (UPDRS) scores indicate the DBS efficacy of the corresponding stimulation location in a particular patient. The spatial distribution of these clinical scores can be used to construct a functional model which closely models the expected efficacy of stimulation in the region. Designs and Methods: In this study, different interpolation techniques were investigated that can appropriately model the DBS …

Construction And Use Of A Direct Calorimeter To Estimate Energy Expenditure In Hibernators, Mark S. Burger, Frank Van Breukelen

Festival of Communities: UG Symposium (Posters)

Metabolic rates have traditionally been estimated through indirect calorimetry (gas exchange or respirometry) due to its ease and availability. Oxygen consumption neglects the contributions of anaerobic metabolism, while direct calorimetry (heat production) estimates both anaerobic and aerobic metabolism. Walsberg and Hoffman (2005) report anaerobic metabolism may be more important to small rodents than was previously thought. During the non-steady state of mammalian hibernation, we hypothesize that anaerobic processes may play an even greater role in fueling metabolism. To address this question, we constructed a very sensitive calorimeter that utilizes the Seebeck effect from a thermoelectric element (Peltier device). We describe …

Dual-Channel Imaging System For Singlet Oxygen And Photosensitizer For Pdt, Seonkyung Lee, Martin E. Isabelle, Kristin L. Gabally-Kinney, Brian W. Pogue, Steven J. Davis

Dartmouth Scholarship

A two-channel optical system has been developed to provide spatially resolved simultaneous imaging of singlet molecular oxygen (¹O₂) phosphorescence and photosensitizer (PS) fluorescence produced by the photodynamic process. The current imaging system uses a spectral discrimination method to differentiate the weak ¹O₂ phosphorescence that peaks near 1.27 μ m from PS fluorescence that also occurs in this spectral region. The detection limit of ¹O₂ emission was determined at a concentration of 500 nM benzoporphyrin derivative monoacid (BPD) in tissue-like phantoms, and these signals observed were proportional to the PS fluorescence. Preliminary in …

Mitochondrial Approaches To Protect Against Cardiac Ischemia And Reperfusion Injury, Amadou K.S. Camara, Martin Bienengraeber, David F. Stowe

Biomedical Engineering Faculty Research and Publications

The mitochondrion is a vital component in cellular energy metabolism and intracellular signaling processes. Mitochondria are involved in a myriad of complex signaling cascades regulating cell death vs. survival. Importantly, mitochondrial dysfunction and the resulting oxidative and nitrosative stress are central in the pathogenesis of numerous human maladies including cardiovascular diseases, neurodegenerative diseases, diabetes, and retinal diseases, many of which are related. This review will examine the emerging understanding of the role of mitochondria in the etiology and progression of cardiovascular diseases and will explore potential therapeutic benefits of targeting the organelle in attenuating the disease process. Indeed, recent advances …

Gas Embolic Factors In Cardiovascular Health, Eric L. Cutler

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

Gas emboli are a clinical issue often encountered in the space exploration, marine construction, and medical fields.  Individuals involved with these disciplines will often have asympomatic gas emboli circulating throughout their bodies on a regular basis.  A study into the impact of chronic asymptomatic gas emboli on the risk of atherosclerosis in humans is thus presented.  This research utilized a custom built cardiovascular flow simulator and accompanying data acquisition system to experimentally determine the influence of gas emboli under varied circumstances on the mean wall shear stress of a tube in-vitro.  A directly inverse relationship between gas embolus presence in …