Biomedical Engineering and Bioengineering Commons^™

Development Of Tissue Engineered Test Systems To Study Mammary Cell Interactions In Vitro, Cheryl Cass

All Dissertations

The work described in this dissertation was conducted in the interdisciplinary research environment of the Clemson University Institute for Biological Interfaces of Engineering. A note at the beginning of each chapter acknowledges, as relevant, collaborating doctoral students and reminds the reader where work from each chapter has been presented or published. The overall goal of this work was to develop tissue engineered test system methodologies to allow the study of mammary cell interactions in vitro. The background, as described in Chapter 1, was published in part in Philosophical Transactions of the Royal Society A in 2010. The studies were designed …

Immunohistochemical Mapping Of Hypoxia In Ischemic Mouse Hindlimb Skeletal Muscle, Emily Deckert

Biomedical Engineering

The study of blood vessel growth and remodeling is a complex endeavor. Hypoxia, the lack of oxygen in a tissue, is known to stimulate angiogenesis (the growth of new blood vessels), and have little effect on arteriogenesis (the enlargement of existing blood vessels). However, the role of hypoxia in vessel function is unknown, but may be determined using the results and methods developed in this experiment.

Supplied by the bloodstream, oxygen is required by all cells and tissues to remain healthy. If the bloodstream supplying a certain tissue with blood is disrupted, the tissue becomes ischemic, often leading to hypoxia. …

Probing The Mechanisms Of Platelet Adhesion To Adsorbed Plasma Proteins, Balakrishnan Sivaraman

All Dissertations

Despite over three decades of research in blood-material interactions, the biomaterials field has been unsuccessful in developing a truly non-thrombogenic biomaterial. This is due to an incomplete understanding of the factors underlying biomaterial-associated thrombosis, especially the mechanisms mediating the interactions of platelets with the adsorbed plasma protein layer(s) on the implant surface. The work presented here is motivated by the primary goal of delineating these mechanisms, and understanding the platelet receptors involved, as well as the domains/amino acid sequences they bind to in the protein molecules.
It is critical to differentiate between the amount and the conformation of the adsorbed …

Evaluation Of Ethanol And Water Introduction Via Fumigation On Efficiency And Emissions Of A Compression Ignition Engine Using An Atomization Technique, Grant S. Janousek

Department of Biological Systems Engineering: Dissertations and Theses

Performance of a diesel engine, equipped for ethanol and water fumigation, was studied. The method implemented allowed for non-destructive introduction of liquids in advance of the turbocharger. Engine torque, speed, emission components, diesel and ethanol fuel rates were recorded and analyzed for each mixture of inputs. Based on the results of the study, thermal efficiency was not significantly different from the baseline diesel performance when using several ethanol and water mixtures. On the other hand, ethanol fumigation caused a significant reduction in NOx emissions and an increase in HC and CO emissions. No significant changes in CO2 or O2 occurred.

Enhanced Anthocyanin Extraction From Red Cabbage Using Pulsed Electric Field Processing, Tanya K. Gachovska, David A. Cassada, Jeyamkondan Subbiah, Milford Hanna, Harshavardhan Thippareddi, Daniel D. Snow

Department of Biological Systems Engineering: Papers and Publications

This study was conducted to evaluate the effect of pulsed electric field (PEF) treatment on anthocyanin extraction from red cabbage using water as a solvent. Mashed cabbage was placed in a batch treatment chamber and subjected to PEF (2.5 kV/cm electric field strength; 15 μs pulse width and 50 pulses, specific energy 15.63 J/g). Extracted anthocyanin concentrations (16 to 889 μg/mL) were determined using HPLC. Heat and light stabilities of the control and PEF-treated samples, having approximately the same initial concentrations, were studied. PEF treatments enhanced total anthocyanin extraction in water from red cabbage by 2.15 times with a higher …

In Vitro Analysis Of Auto-Loom Woven Test Patches For Hernia Repair, Bryant Mersereau

All Theses

Hernias are defects in the layers of the abdominal wall that can cause discomfort or pain and lead to serious health problems if left untreated. A significant portion of the world's population is afflicted by hernia formation, and the cost of treating those affected is in the billions of dollars in the US alone. The current best practices for repairing hernias involve the surgical implantation of polymeric meshes over and around the defect site. The mesh, acting as a synthetic replacement for the damaged abdominal wall layers, provides a barrier to further visceral protrusions through the defect, a support framework …

Structural Bioinformatics Based Method For Predicting The Initial Adsorbed Protein Orientation On A Surface, Aby Thyparambil

All Theses

In any molecular simulation of protein-surface interaction, the selection of the initial orientation with which the protein would interact with the surface must be first made and is found to be critical in the determination of the bioactive state of the adsorbed protein. While various molecular simulation methods have been developed to identify the preferred orientation, these methods are generally computationally expensive and time consuming, especially for large molecules thereby motivating the current study.
The computational implementation for identifying a preferred orientation was done in MATLAB¨ and directly addresses the current research problem by assuming the protein to be rigid …

Hemocompatibility And Endothelialization Of Elastin And Collagen Scaffolds: The Role Of Plasma Proteins, Shear Stress And Integrins, Nithya Swaminathan

All Theses

Cardiovascular diseases are the leading cause of death worldwide as reported by the World Health Organization. Biomaterials have been extensively used in blood-contacting applications as heart valves, stents, grafts and catheters. However failure due to thrombosis hinders the long term patency and potential of these devices. Purified elastin scaffolds derived from porcine arteries as potential vascular graft materials are being investigated in our laboratory. In this study, we investigated the influence of factors such as shear stress and the presence of plasma proteins on the platelet response, and endothelial cell retention on purified elastin scaffolds to evaluate their hemocompatibility.

Elastin …

St. Jude Medical: Enhanced Mics (Emics), Devanshi Shah

Master's Theses

Heart disease is one of the most prevalent diseases in the world. The survival chances for patients with ventricular fibrillation/ventricular tachycardia reduces significantly as time passes without treatment and even after getting timely treatment recurring episode are common. These patients can benefit from an Implantable Cardioverter Defibrillator (ICD) which can monitor heart rhythm and provide immediate treatment. Due to the ever changing physical conditions and disease progression, the ICD needs to collect diagnostic data as well as support programming by the physician. The ICD uses inductive telemetry and radio-frequency telemetry for the communication with the external devices such as a …

Integration Of Microfluidics With Surface Plasmon Resonance, Scott B. Fratzke

Master's Theses

This thesis successfully integrates laminate microfluidic devices with an analytic Surface Plasmon Resonance (SPR) instrument. Integration was accomplished at low-cost using materials such as polydimethylsiloxane (PDMS), Poly(methyl methacrylate) (PMMA), Tygon tubing, and a 3-way stopcock. The main components of this thesis are the design and fabrication of the low-cost, in-house fluidics that can integrate with upstream microfluidics and the validation of the in-house fluidics using the Biosensing Instruments BI-2000 SPR instrument. The low-cost fluidics was designed and fabricated “in-house” using a novel investment casting technique that required the use of laser cutting technology to make a master cast, and candle …

St. Jude Medical: An Object-Oriented Software Architecture For Embedded And Real-Time Medical Devices, Atila Amiri

Master's Theses

Medical devices used for surgical or therapeutic purposes require a high degree of safety and effectiveness. Software is critical component of many such medical devices. The software architecture of a system defines organizational structure and the runtime characteristic of the application used to control the operation of the system and provides a set of frameworks that are used to develop that. As such, the design of software architecture is a critical element in achieving the intended functionality, performance, and safety requirements of a medical device. This architecture uses object-oriented design techniques, which model the underlying system as a set of …

Pre-Swing Deficits In Forward Propulsion, Swing Initiation And Power Generation By Individual Muscles During Hemiparetic Walking, Carrie Peterson, Allison Kinney, Stephen Kautz, Richard Neptune

Allison Kinney

No abstract provided.

Eye Movements In Elite Athletes - An Index For Performance., Harshad Hegde

Theses and Dissertations

Introduction: In gymnastics, athletes perform twisting and flipping skills at high angular velocities. These athletes rely heavily on sensory information from the visual, proprioceptive, and vestibular systems. The vestibulo-ocular reflex (VOR) is responsible for stabilizing the visual field on the retina during head movement. To accomplish this, the eyes are reflexively moved in a direction opposite the head. In a twisting gymnast, this actually reduces the ability of gymnasts to see the landing during airborne skills. Hence it becomes necessary for the gymnasts to cancel or suppress their VOR in order to view the landing. Objective: The purpose of this …

Effect Of Mechanical Stimulation On Mesenchymal Stem Cell Seeded Cartilage Constructs, Karin Wartella

Theses and Dissertations

Cartilage tissue engineered constructs using mesenchymal stem cells were stimulated with 3 different stimulation algorithms to achieve characteristics mimicking the superficial tangential zone of articular cartilage. The stimulation algorithm of both compression and tension without an offset had the best properties out of all the evaluated groups.

Synthesis And Characterization Of A Novel Amphiphilic Core-Corona Hyperbranched Polymer, Composed Of Ehmo And Ehmopeg, For Drug Delivery., Khushboo Sharma

Theses and Dissertations

A novel amphiphilic core-corona hyperbranched polymer, composed of 3-ethyl-3-(hydroxylmethyl) oxetane (EHMO) and PEGylated EHMO (EHMOPEG), was synthesized through cationic ring opening polymerization. Nuclear Magnetic Resonance spectroscopy (NMR), Dynamic Light Scattering (DLS), and Fourier Transform Infrared spectroscopy (FTIR) were used to characterize the polymer structure and degree of branching. It was found that the degree of branching (DOB) of the polymer was affected by the weight % ratios of EHMO/EHMOPEG used in polymerization. As the weight % ratio of EHMO/ EHMOPEG decreased, the DOB was observed to increase. Polymeric particles based on the synthesized polymer were prepared using the O/W (Oil …

Characterizing Accuracy Of Total Hemoglobin Recovery Using Contrast-Detail Analysis In 3d Image-Guided Near Infrared Spectroscopy With The Boundary Element Method, Hamid R. Ghadyani, Subhadra Srinivasan, Brian W. Pogue, Keith D. Paulsen

Dartmouth Scholarship

The quantification of total hemoglobin concentration (HbT) obtained from multi-modality image-guided near infrared spectroscopy (IG-NIRS) was characterized using the boundary element method (BEM) for 3D image reconstruction. Multi-modality IG-NIRS systems use a priori information to guide the reconstruction process. While this has been shown to improve resolution, the effect on quantitative accuracy is unclear. Here, through systematic contrast-detail analysis, the fidelity of IG-NIRS in quantifying HbT was examined using 3D simulations. These simulations show that HbT could be recovered for medium sized (20mm in 100mm total diameter) spherical inclusions with an average error of 15%, for the physiologically …

Improved Detection Limits Using A Hand-Held Optical Imager With Coregistration Capabilities, Sarah J. Erickson, Sergio Martinez, Jean Gonzalez, Lizeth Caldera, Anuradha Godavarty

Department of Biomedical Engineering Faculty Publications

Optical imaging is emerging as a non-invasive and non-ionizing method for breast cancer diagnosis. A hand-held optical imager has been developed with coregistration facilities towards flexible imaging of different tissue volumes and curvatures in near real-time. Herein, fluorescence-enhanced optical imaging experiments are performed to demonstrate deeper target detection under perfect and imperfect (100:1) uptake conditions in (liquid) tissue phantoms and in vitro. Upon summation of multiple scans (fluorescence intensity images), fluorescent targets are detected at greater depths than from single scan alone.

Posture Influences Ground Reaction Force: Implications For Crouch Gait, H. X. Hoang, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

Improving Computed Muscle Control Through Optimization To Generate Dynamic Simulations Of Overground Running, Jeffrey A. Reinbolt, C. J. Donnelly

Jeffrey A. Reinbolt

No abstract provided.

Investigation Of Buildup Dose For Therapeutic Intensity Modulated Photon Beams In Radiation Therapy, Khosrow Javedan

USF Tampa Graduate Theses and Dissertations

Buildup dose of Mega Voltage (MV) photon beams can be a limiting factor in intensitymodulated radiation therapy (IMRT) treatments. Excessive doses can cause patient discomfort and treatment interruptions, while underdosing may lead to local failure.

Many factors which contribute to buildup dose, including the photon beam energy spectrum, scattered or contaminant radiation and their angular distribution, are not modeled well in commercial treatment planning systems. The accurate Monte Carlo method was employed in the studies to estimate the doses.

Buildup dose of 6MV photon beams was investigated for three fundamentally different IMRT modalities: between Helical TomoTherapy and traditional opposed tangential …