Engineering Commons^™

Investigation Of Physiochemical Properties Of A Novel Gradient Calcium Polyphosphate Bone Scaffold And Its Influence On Cellular Behavior, Liang Chen

Wayne State University Theses

A good designed bone scaffold is crucial to bone tissue engineering. We have developed and characterized a novel gradient bone scaffold by combination of Calcium Polyphosphate (CPP) with different size of porogen (stearic acids). Compared with homogenous scaffold, the gradient bone scaffold with different pore size and porosity can better mimic natural bone structure. Directly perfusion flow bioreactor was developed. This 3D dynamic cell culture was better mimic the physiological condition for cell growth. It was beneficial to nutrition and oxygen delivery throughout the whole scaffold and was able to form shear stress. We wanted to investigate the effect of …

The Role Of Tissue Sound Speed As A Surrogate Marker Of Breast Density, Mark Sak

Wayne State University Dissertations

Breast density is one of the strongest predictors of breast cancer risk as women with the densest breasts have a three- to five-fold increase in risk compared to women with the least dense breasts. Breast density is currently measured by using mammography, the current gold standard for breast imaging. There are many shortcomings to using mammography to measure breast density, including the use of ionizing radiation. Ultrasound tomography (UST) does not use ionizing radiation and can create tomographic breast sound speed images. These sound speed images are useful because breast density is proportional to sound speed. The purpose of this …

An Investigation Of The Biochemical Properties Of Tetrazines As Potential Coating Additives, Swarna Jaiswal, Brendan Duffy, Luke O'Neill, Patrick Mchale

Articles

1,2,4,5-Tetrazine and its 3,6-disubstituted derivatives are currently used for a range of industrial and medical applications as they exhibit particular coordination chemistries, characterized by electron and charge transfer phenomena. The aim of the present work is to describe the synthesis of two tetrazine derivatives, namely 3,6-dihydrazino-1,2,4,5-tetrazine (DHDTZ) and 1,2,4,5-tetrazine dicarboxylic acid (DCTZ), and determine their antibacterial, antioxidant and anticorrosion characteristics as additives in a sol-gel coating on SS316L steel. The structure of the tetrazines was confirmed by NMR and FTIR while the surface morphology of bacterial cells in their presence was observed by AFM. Their ability to inhibit corrosion on …

Finite Element Analysis Of Balloon-Expandable Coronary Stent Deployment: Influence Of Angioplasty Balloon Configuration, David Martin, Fergal Boyle

Articles

Today, the majority of coronary stents are balloon-expandable and are deployed using a balloon-tipped catheter. To improve deliverability, the membrane of the angioplasty balloon is typically folded about the catheter in a pleated configuration. As such, the deployment of the angioplasty balloon is governed by the material properties of the balloon membrane, its folded configuration and its attachment to the catheter. Despite this observation, however, an optimum strategy for modelling the configuration of the angioplasty balloon in finite element studies of coronary stent deployment has not been identified, and idealised models of the angioplasty balloon are commonly employed in the …

Techniques To Quantify The Size Of Protein Colloids In Amyloid Fiber Formation, Jonathan R. Anson, Chia-Hung Lu, Lingwen Cui, Xiaojing Yang, Shaohua Xu

Biomedical Engineering and Sciences Faculty Publications

A new method for the analysis of protein colloidal diameter has been developed using three existing protein concentration quantification techniques, absorption at 280 nm, colloidal gold assay, and DC protein assay. Protein colloids are formed in the process of aggregation and are thought to be intermediates in protein self-assembly and formation of amyloid fiber. Deposition of the protein fibers in tissues leads to numerous human diseases including Alzheimer’s. Lysozyme was incubated at pH 2.0, 55°C, an environment conducive to amyloid fiber formation. The protein colloids present in the supernatant of the samples after centrifugation were studied over a time course …

The Effects Of Hydrostatic Pressure On Early Endothelial Tubulogenic Processes, Ryan M. Underwood

Theses and Dissertations--Biomedical Engineering

The effects of mechanical forces on endothelial cell function and behavior are well documented, but have not been fully characterized. Specifically, fluid pressure has been shown to elicit physical and chemical responses known to be involved in the initiation and progression of endothelial cell-mediated vascularization. Central to the process of vascularization is the formation of tube-like structures. This process—tubulogenesis—is essential to both the physiological and pathological growth of tissues. Given the known effects of pressure on endothelial cells and its ubiquitous presence in the vasculature, we investigated pressure as a magnitude-dependent parameter for the regulation of endothelial tubulogenic activity. To …

Myoglobin Detection On Sic: Immunosensor Development For Myocardial Infarction, Alexandra Oliveros Villalba

USF Tampa Graduate Theses and Dissertations

Silicon carbide (SiC) has been around for more than 100 years as an industrial material and has found wide and varied applications because of its unique electrical and thermal properties. In recent years there has been increased attention on SiC as a viable material for biomedical applications. Among these applications are those where SiC is used as a substrate material for biosensors and biotransducers, taking advantage of its surface chemical, tribological and electrical properties.

In this work we have used the proven bio- and hema-compatibility of SiC to develop a viable biorecognition interface using SiC as the substrate material for …

Vapor-Liquid-Solid(Vls) Grown Silica (Siox) Nanowires As The Interface For Biorecognition Molecules In Biosensors, Eduardo Murphy-Pérez

USF Tampa Graduate Theses and Dissertations

SiOx nanowires grown through the VLS mechanism were electrophoretically deposited on top of Au electrodes. GOx was immobilized using APTES and the EDC-NHS chemistry. Cyclic Voltammetry was used as the method to characterize the electrodes through their processing steps, and CV was also used to detect glucose in a PBS based solution. Ferro-Ferri Cyanide couple was used as the mediator.

Probe Immobilization Strategies And Device Optimization For Novel Transistor-Based Dna Sensors, Nicholas Michael Fahrenkopf

Legacy Theses & Dissertations (2009 - 2024)

The research presented herein exploits the terminal phosphate group on single stranded DNA molecules for direct immobilization to surfaces utilized in semiconductor device fabrication with the end goal of transistor based DNA sensors. As a demonstration of the feasibility of this immobilization strategy DNA immobilization to a variety of surfaces was evaluated for usefulness in biosensor applications. It was determined that DNA can be directly immobilized to a variety of semiconductor surfaces through the terminal phosphate group. Further, this immobilization allows for the hybridization of the immobilized DNA to complementary target in solution. The immobilization of DNA to hafnium dioxide …

In Vivo Dark-Field Imaging Of The Retinal Pigment Epithelium Cell Mosaic, Drew Scoles, Yusufu N. Sulai, Alfredo Dubra

Biomedical Engineering Faculty Research and Publications

Non-invasive reflectance imaging of the human RPE cell mosaic is demonstrated using a modified confocal adaptive optics scanning light ophthalmoscope (AOSLO). The confocal circular aperture in front of the imaging detector was replaced with a combination of a circular aperture 4 to 16 Airy disks in diameter and an opaque filament, 1 or 3 Airy disks thick. This arrangement reveals the RPE cell mosaic by dramatically attenuating the light backscattered by the photoreceptors. The RPE cell mosaic was visualized in all 7 recruited subjects at multiple retinal locations with varying degrees of contrast and cross-talk from the photoreceptors. Various experimental …

Brittle Bone Fracture Risk With Transverse Isotropy, Jessica M. Fritz, Nicole M. Grosland, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Bone Properties By Nanoindentation In Mild And Severe Osteogenesis Imperfecta, Carolyne Albert, John Jameson, Jeffrey M. Toth, Peter Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Background

Osteogenesis imperfecta is a heterogeneous genetic disorder characterized by bone fragility. Previous research suggests that impaired collagen network and abnormal mineralization affect bone tissue properties, however, little data is yet available to describe bone material properties in individuals with this disorder. Bone material properties have not been characterized in individuals with the most common form of osteogenesis imperfecta, type I.

Methods

Bone tissue elastic modulus and hardness were measured by nanoindentation in eleven osteotomy specimens that were harvested from children with osteogenesis imperfecta during routine surgeries. These properties were compared between osteogenesis imperfecta types I (mild, n = …

Comparison Of Randomized Multifocal Mapping And Temporal Phase Mapping Of Visual Cortex For Clinical Use, Yan Ma, B. Douglas Ward, Kristina M. Ropella, Edgar A. Deyoe

Biomedical Engineering Faculty Research and Publications

fMRI is becoming an important clinical tool for planning and guidance of surgery to treat brain tumors, arteriovenous malformations, and epileptic foci. For visual cortex mapping, the most popular paradigm by far is temporal phase mapping, although random multifocal stimulation paradigms have drawn increased attention due to their ability to identify complex response fields and their random properties. In this study we directly compared temporal phase and multifocal vision mapping paradigms with respect to clinically relevant factors including: time efficiency, mapping completeness, and the effects of noise. Randomized, multifocal mapping accurately decomposed the response of single voxels to multiple stimulus …

A Hands-On, Active Learning Approach To Increasing Manufacturing Knowledge In Engineering Students, Jay R. Goldberg, David B. Rank

Biomedical Engineering Faculty Research and Publications

This paper describes a new learning module implemented as part of the senior capstone design course at Marquette University to teach engineering students about basic manufacturing processes, lean manufacturing principles, and design for manufacturability. The module includes several examples of active and student centered learning as part of an in-class assembly line simulation exercise. Students reflected on this experience, and suggested process improvements to save time, reduce cost and waste, and improve the assembly line process. They learned of the importance of manufacturing documentation, process design, and design for assembly. At the end of the module, students understood the importance …

Biplane Fluoroscopic Analysis Of The Hindfoot Using Model-Based Tracking Techniques: A Static Phantom Study, Janelle A. Cross, Ben Mchenry, Gerald F. Harris, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

No abstract provided.

White Matter Structural Connectivity Is Associated With Sensorimotor Function In Stroke Survivors, Benjamin Kalinosky, Sheila M. Schindler-Ivens, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Purpose

Diffusion tensor imaging (DTI) provides functionally relevant information about white matter structure. Local anatomical connectivity information combined with fractional anisotropy (FA) and mean diffusivity (MD) may predict functional outcomes in stroke survivors. Imaging methods for predicting functional outcomes in stroke survivors are not well established. This work uses DTI to objectively assess the effects of a stroke lesion on white matter structure and sensorimotor function.

Methods

A voxel-based approach is introduced to assess a stroke lesion's global impact on motor function. Anatomical T1-weighted and diffusion tensor images of the brain were acquired for nineteen subjects (10 post-stroke and 9 …

Toward Directing Cell Fate: Carbon Nanotubes As Modulators Of Extracellular And Transporters Of Intracellular Cues, Qingsu Cheng

Theses and Dissertations

The unique properties of CNTs lead CNTs attractive in biological engineering applications. It is expected to use CNT based biomaterials for clinic use in the near future. CNTs can be used to tune cellular fate through bother extracellular pathway and intracellular pathway. CNT based biomaterials has been applied into bone, nerves, and cardiovascular system. There has also been progress in the use of CNTs in controlling cellular alignment, to enhance tissue regeneration, growth factor delivery and gene delivery.

Pluripotent stem cells (hPSCs) offer a promising tool in tissue engineering strategies, as their differentiated derivatives can be used to reconstruct most …

Automatic Detection Of Polypoid Skin Lesions: The Squash Sign, Saurabh G. Karnik

Masters Theses

“Earlier detection of malignant melanoma can save lives. Automatic in-vivo methods of melanoma detection including smart-phone applications are now available, but specificity is low, i.e. too many benign lesions are detected as possible melanomas. Polypoids, elevated and rounded lesions are one class of benign lesions. These raised lesions with piecewise circular borders, predominantly intradermal nevi and cutaneous polyps (IDNs), are always benign. Variegated coloring present in polypoid lesions can lead physicians to perform an unneeded biopsy. Contact dermatoscope plates with gel squash these lesions, leaving a “squash sign” marker of benignancy which can be automatically detected. We present a method …

Significance And Analysis Of Milia-Like Cysts In Dermoscopy Skin Lesion Images, Sneha K. Mahajan

Masters Theses

“Milia-like cysts (MLCs) are dermoscopic structures frequently observed in seborrheic keratoses(SKs), which are the most common type of skin lesions. Diverse appearances of these skin lesions make them difficult to differentiate from melanoma, a deadly type of skin cancer. Classified by size into two main groups, starry MLCs and cloudy MLCs, the presence of these structures in a skin lesion has been known to help differentiate benign lesions from melanoma. Though the presence of cloudy MLCs is not exclusively associated with SKs, they can be a useful tool to differentiate SKs from melanoma. This research study determines the statistical occurrence …

Hyperglycemia Induces Differential Change In Oxidative Stress At Gene Expression And Functional Levels In Huvec And Hmvec, Hemang Patel, Juan Chen, Kumuda C. Das, Mahendra Kavdia

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Endothelial dysfunction precedes pathogenesis of vascular complications in diabetes. In recent years, the mechanisms of endothelial dysfunction were investigated to outline strategies for its treatment. However, the therapies for dysfunctional endothelium resulted in multiple clinical trial failures and remain elusive. There is a need for defining hyperglycemia-induced endothelial dysfunction with both generic and specific dysfunctional changes in endothelial cells (EC) using a systems approach. In this study, we investigated hyperglycemia-induced endothelial dysfunction in HUVEC and HMVEC. We investigated hyperglycemia-induced functional changes (superoxide (O₂‾), and hydrogen peroxide (H₂O₂) production and mitochondrial membrane polarization) …

Synthesis And Characterization Of Biodegradable Poly(Vinyl Esters) With Hdac Inhibitory Activity, Kyle Lawrence Horton

Wayne State University Theses

HDAC inhibitors are known to have anti-inflammatory properties. HDAC inhibitors are used in combination with Oct4 to generate induced pluripotent stem cells. I hypothesized that polyesters based on simple aliphatic HDAC inhibitors like valproic acid (VPA) and phenylbutyric acid (PBA) can serve as alternatives to existing polyester biomaterials with improved anti-inflammatory properties and as scaffolds for generation of iPSCs when used in combination with layer-by-layer thin films delivering reprogramming transcription factors. Vinyl ester of phenylbutyric acid (VEPA) and vinyl ester of valproic acid (VEVA) were synthesized from their carboxylic acid precursors using an iridium complex catalyst at yields as high …

Compressed Sensing And Joint Acquisition Techniques In Mri, Rouhollah Hamtaei

Wayne State University Theses

The relatively long scan times in Magnetic Resonance Imaging (MRI) limits some clinical applications and the ability to collect more information in a reasonable period of time. Practically, 3D imaging requires longer acquisitions which can lead to a reduction in image quality due to motion artifacts, patient discomfort, increased costs to the healthcare system and loss of profit to the imaging center. The emphasis in reducing scan time has been to a large degree through using limited k-space data acquisition and special reconstruction techniques. Among these approaches are data extrapolation methods such as "constrained reconstruction" techniques, data interpolation methods such …

Thermal Stability And Decomposition Of Diesel Fuel Under Subcritical And Supercritical Conditions, Ronghong Lin, Lawrence L. Tavlarides

Biomedical and Chemical Engineering - All Scholarship

A novel concept of clean diesel combustion using supercritical fluids is proposed and being investigated to address some key challenges encountered in the fuel and transportation sector. The core of this concept is to inject diesel fuel (DF) in the supercritical state to achieve clean, high-efficient combustion in diesel engines. Among other challenging issues that must be addressed for the implementation of this new concept is the thermal stability of DF and the potential decomposition and solid deposit formation under engine conditions. In this work, thermal stability of DF was experimentally evaluated under subcritical and supercritical conditions in both static …

A Biocompatible Sic Rf Antenna For In-Vivo Sensing Applications, Shamima Afroz

USF Tampa Graduate Theses and Dissertations

A continuous glucose sensor employing radio frequency (RF) signals is presented using the biocompatible material Silicon Carbide (SiC). Unlike biosensors that require direct contact with interstitial fluids to trigger chemical reactions to operate, this biocompatible SiC sensor does not require a direct interface. The sensing mechanism for this SiC sensor is based upon a shift in resonant frequency, as a function of change in glucose levels, which electrically manifests itself as a change in blood permittivity and

conductivity. For in vivo applications the antenna sensor needs to operate inside the body environment, and it has been found that the best …

Slowing The Onset Of Hypoxia Increases Colony Forming Efficiency Of Connective Tissue Progenitor Cells In Vitro, Christopher M. Heylman, Tonya N. Caralla, Cynthia A. Boehm, Thomas E. Patterson, George F. Muschler

Biomedical Engineering

Background: Survival and colony formation by transplanted tissue derived connective tissue progenitor cells (CTPs) are thought to be important factors in the success of clinical tissue engineering strategies for bone regeneration. Transplantation of cells into defects larger than a few millimeters expose cells to a profoundly hypoxic environment. This study tested the hypothesis that delaying the onset of hypoxia will improve the survival and performance of CTPs in vitro.

Methods: To mimic declines seen in an avascular in vivo bone defect, colony forming efficiency by marrow derived nucleated cells was assessed under osteogenic conditions. Variation in the rate of …

Independent Component Analysis Enhancements For Source Separation In Immersive Audio Environments, Yue Zhao

Theses and Dissertations--Electrical and Computer Engineering

In immersive audio environments with distributed microphones, Independent Component Analysis (ICA) can be applied to uncover signals from a mixture of other signals and noise, such as in a cocktail party recording. ICA algorithms have been developed for instantaneous source mixtures and convolutional source mixtures. While ICA for instantaneous mixtures works when no delays exist between the signals in each mixture, distributed microphone recordings typically result various delays of the signals over the recorded channels. The convolutive ICA algorithm should account for delays; however, it requires many parameters to be set and often has stability issues. This thesis introduces the …

Development Of An Eeg Brain-Machine Interface To Aid In Recovery Of Motor Function After Neurological Injury, Elizabeth Salmon

Theses and Dissertations--Biomedical Engineering

Impaired motor function following neurological injury may be overcome through therapies that induce neuroplastic changes in the brain. Therapeutic methods include repetitive exercises that promote use-dependent plasticity (UDP), the benefit of which may be increased by first administering peripheral nerve stimulation (PNS) to activate afferent fibers, resulting in increased cortical excitability. We speculate that PNS delivered only in response to attempted movement would induce timing-dependent plasticity (TDP), a mechanism essential to normal motor learning. Here we develop a brain-machine interface (BMI) to detect movement intent and effort in healthy volunteers (n=5) from their electroencephalogram (EEG). This could be used in …

Noninvasive Near-Infrared Diffuse Optical Monitoring Of Cerebral Hemodynamics And Autoregulation, Ran Cheng

Theses and Dissertations--Biomedical Engineering

Many cerebral diseases are associated with abnormal cerebral hemodynamics and impaired cerebral autoregulation (CA). CA is a mechanism to maintain cerebral blood flow (CBF) stable when mean arterial pressure (MAP) fluctuates. Evaluating these abnormalities requires direct measurements of cerebral hemodynamics and MAP. Several near-infrared diffuse optical instruments have been developed in our laboratory for hemodynamic measurements including near-infrared spectroscopy (NIRS), diffuse correlation spectroscopy (DCS), hybrid NIRS/DCS, and dual-wavelength DCS flow-oximeter. We utilized these noninvasive technologies to quantify CBF and cerebral oxygenation in different populations under different physiological conditions/manipulations. A commercial finger plethysmograph was used to continuously monitor MAP. For investigating …

Effects Of Acute Stretch On Cardiac Electrical Properties In Swine, Anuj Agarwal

Theses and Dissertations--Biomedical Engineering

Stretch is known to result in an electrically less stable ventricular substrate, yet the reported effects of stretch on measured electrophysiological parameters have been inconsistent and even contradictory. The goal of this study was to evaluate the effects of acute mechanical stretch on cardiac electrical features thought to be key in generation of arrhythmia, namely restitution of action potential duration (APD), electrical memory, and onset of alternans.

Microelectrodes were used to record intracellular potentials pre, during, and post-stretch from isolated right ventricular tissues from swine. In separate experiments, the effects of two levels of stretch were quantified. Pacing protocols employing …

Hysteresis In Repolarization Of Cardiac Action Potentials: Effects Of Spatial Heterogeneity And Slow Repolarization Currents, Linyuan Jing

Theses and Dissertations--Biomedical Engineering

Repolarization alternans, i.e. beat-to-beat variation of repolarization of action potential, is proposed as a predictor of life-threatening arrhythmias. Restitution relates repolarization duration with its previous relaxation time, i.e. diatstolic interval (DI), and is considered a dominant mechanism for alternans. Previously, we observed that different repolarization durations at the same DI during decelerating and accelerating pacing, i.e. restitution displays hysteresis, which is a measure of “cardiac memory”.

Objective of the current study was to investigate in the pig 1) the mechanism for a previously observed hysteresis type phenomenon, where alternans, once started at higher heart rate, persists even when heart rate …