Biomedical Engineering and Bioengineering Commons^™

Sic For Advanced Biological Applications, Joseph Register

USF Tampa Graduate Theses and Dissertations

Silicon carbide (SiC) has been used for centuries as an industrial abrasive and has been

actively researched since the 1960's as a robust material for power electronic applications.

Despite being the first semiconductor to emit blue light in 1907, it has only recently been

discovered that the material has crucial properties ideal for long-term, implantable biomedical

devices. This is due to the fact that the material offers superior biocompatibility and

hemocompatibility while providing rigid mechanical and chemical stability. In addition, the material

is a wide-bandgap semiconductor that can be used for optoelectronics, light delivery, and optical

sensors, which is the …

Combined Metal-Enhanced Fluorescence-Surface Acoustic Wave (Mef-Saw) Biosensor, Samuel Morrill

USF Tampa Graduate Theses and Dissertations

Immunofluorescence assays are capable of both detecting the amount of a protein and the location of the protein within a cell or tissue section. Unfortunately, the traditional technique is not capable of detecting concentrations on the nanoscale. Also, the technique suffers from non-specific attachment, which can cause false-positives, as well as photobleaching when detecting lower concentrations is attempted. There is also a time constraint problem since the technique can take from many hours to a few days in some cases.

In this work, metal-enhanced fluorescence (MEF) is used to lower the detection limit and reduce photobleaching. Unfortunately, MEF also increases …

Feature Selection On Hyperspectral Data For Dismount Skin Analysis, Lindsay R. Cain

Theses and Dissertations

Many security applications require the ability to accurately identify dismounts based on their distinctive identification properties. A dismount can be identified by many personal characteristics to include clothing, height, and gait. In particular, a dismount's skin can be used as an identifying feature because of the vast variability of skin pigmentation amongst individuals. Hyperspectral data, which is comprised of hundreds of spectral channels sampled from a nearly contiguous electromagnetic spectrum, is used to detect skin spectral variability amongst dismounts. However, hyperspectral data is often highly correlated and computationally expensive to process. Feature selection methods can be employed to reduce the …

An Analysis Of Eye Movements With Helmet Mounted Displays, Kalyn A. Tung

Theses and Dissertations

Helmet or Head-Mounted Displays (HMD) applications have expanded to include a range from advanced military cockpits to consumer glasses. However, users have documented loss of legibility while undergoing vibration. Recent research indicates that undesirable eye movement is related to the vibration frequency a user experiences. In vibrating environments, two competing eye reflexes likely contribute to eye movements. The Vestibulo-ocular Reflex responds to motion sensed in the otoliths while the pursuit reflex is driven by the visual system to maintain the desired image on the fovea. This study attempts to isolate undesirable eye motions that occur while using a HMD by …

Atlas-Guided Volumetric Diffuse Optical Tomography Enhanced By Generalized Linear Model Analysis To Image Risk Decision-Making Responses In Young Adults, Zi-Jing Lin, Lin Li, Mary Cazzell, Hanli Liu

Bioengineering Faculty Publications - Archive

No abstract provided.

Application Of Sub-Micrometer Vibrations To Mitigate Bacterial Adhesion, Will R. Paces, Hal Holmes, Eli Vlaisavljevich, Katherine L. Snyder, Ee Lim Tan, Rupak Rajachar, Keat Ghee Ong

Michigan Tech Publications, Part 1

As a prominent concern regarding implantable devices, eliminating the threat of opportunistic bacterial infection represents a significant benefit to both patient health and device function. Current treatment options focus on chemical approaches to negate bacterial adhesion, however, these methods are in some ways limited. The scope of this study was to assess the efficacy of a novel means of modulating bacterial adhesion through the application of vibrations using magnetoelastic materials. Magnetoelastic materials possess unique magnetostrictive property that can convert a magnetic field stimulus into a mechanical deformation. In vitro experiments demonstrated that vibrational loads generated by the magnetoelastic materials significantly …

Assessing Visual Perception Using Behaviour Conditioning In The Rat Model, Patricia Bacala

Rose-Hulman Undergraduate Research Publications

Neural prosthetics aim to restore function to sensory deficits. In the same sense that cochlear implants can restore auditory function, visual neural prosthetics aim to restore visual function. A strain of rats with retinal degeneration are subjects of great interest when exploring the effect of a visual neural prosthetics on visual perception. In this study we explore the rat response to a visual stimulus in normal vision rats through behavior conditioning in the development of a training protocol that will be used to assess visual perception in retinal degenerative rats. We found that autoshaping was a successful method in training …

Quantitative Relaxometry And Diffusion Mri For Lateralization In Mts And Non-Mts Temporal Lobe Epilepsy., Ali R Khan, Maged Goubran, Sandrine De Ribaupierre, Robert R Hammond, Jorge G Burneo, Andrew G Parrent, Terry M Peters

Robarts Imaging Publications

We developed novel methodology for investigating the use of quantitative relaxometry (T1 and T2) and diffusion tensor imaging (DTI) for lateralization in temporal lobe epilepsy. Patients with mesial temporal sclerosis confirmed by pathology (N=8) and non-MTS unilateral temporal lobe epilepsy (N=6) were compared against healthy controls (N=19) using voxel-based analysis restricted to the anterior temporal lobes, and laterality indices for each MRI metric (T1, T2, fractional anisotropy (FA), mean diffusivity, axial and radial diffusivities) were computed based on the proportion of significant voxels on each side. The diffusivity metrics were the most lateralizing MRI metrics in MTS and non-MTS subsets, …

Characterizing Phantom Arteries With Multi-Channel Laser Ultrasonics And Photo-Acoustics, Jami L. Johnson, Kasper Van Wijk, Michelle Sabick

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Multi-channel photo-acoustic and laser ultrasonic waves are used to sense the characteristics of proxies for healthy and diseased vessels. The acquisition system is non-contacting and non-invasive with a pulsed laser source and a laser vibrometer detector. As the wave signatures of our targets are typically low in amplitude, we exploit multi-channel acquisition and processing techniques. These are commonly used in seismology to improve the signal-to-noise ratio of data. We identify vessel proxies with a diameter on the order of 1 mm, at a depth of 18 mm. Variations in scattered and photo-acoustic signatures are related to differences in vessel wall …

Classification Of Human Retinal Microaneurysms Using Adaptive Optics Scanning Light Ophthalmoscope Fluorescein Angiography, Michael Dubow, Alexander Pinhas, Nishit Shah, Robert F. Cooper, Alexander Gan, Ronald C. Gentile, Vernon Hendrix, Yusufu N. Sulai, Joseph Carroll, Toco Y.P. Chui, Joseph B. Walsh, Rishard Weitz, Alfredo Dubra, Richard B. Rosen

Biomedical Engineering Faculty Research and Publications

Purpose.

Microaneurysms (MAs) are considered a hallmark of retinal vascular disease, yet what little is known about them is mostly based upon histology, not clinical observation. Here, we use the recently developed adaptive optics scanning light ophthalmoscope (AOSLO) fluorescein angiography (FA) to image human MAs in vivo and to expand on previously described MA morphologic classification schemes.

Methods.

Patients with vascular retinopathies (diabetic, hypertensive, and branch and central retinal vein occlusion) were imaged with reflectance AOSLO and AOSLO FA. Ninety-three MAs, from 14 eyes, were imaged and classified according to appearance into six morphologic groups: focal bulge, saccular, fusiform, mixed, …

Comparison Of Adaptive Optics Scanning Light Ophthalmoscopic Fluorescein Angiography And Offset Pinhole Imaging, Toco Y.P. Chui, Michael Dubow, Alexander Pinhas, Nishit Shah, Alexander Gan, Rishard Weitz, Yusufu N. Sulai, Alfredo Dubra, Richard B. Rosen

Biomedical Engineering Faculty Research and Publications

Recent advances to the adaptive optics scanning light ophthalmoscope (AOSLO) have enabled finer in vivo assessment of the human retinal microvasculature. AOSLO confocal reflectance imaging has been coupled with oral fluorescein angiography (FA), enabling simultaneous acquisition of structural and perfusion images. AOSLO offset pinhole (OP) imaging combined with motion contrast post-processing techniques, are able to create a similar set of structural and perfusion images without the use of exogenous contrast agent. In this study, we evaluate the similarities and differences of the structural and perfusion images obtained by either method, in healthy control subjects and in patients with retinal vasculopathy …

Isoflurane Modulates Cardiac Mitochondrial Bioenergetics By Selectively Attenuating Respiratory Complexes, Bhawana Agarwal, Ranjan K. Dash, David F. Stowe, Zeljko J. Bosnjak, Amadou K.S. Camara

Biomedical Engineering Faculty Research and Publications

Mitochondrial dysfunction contributes to cardiac ischemia–reperfusion (IR) injury but volatile anesthetics (VA) may alter mitochondrial function to trigger cardioprotection. We hypothesized that the VA isoflurane (ISO) mediates cardioprotection in part by altering the function of several respiratory and transport proteins involved in oxidative phosphorylation (OxPhos). To test this we used fluorescence spectrophotometry to measure the effects of ISO (0, 0.5, 1, 2 mM) on the time-course of interlinked mitochondrial bioenergetic variables during states 2, 3 and 4 respiration in the presence of either complex I substrate K⁺-pyruvate/malate (PM) or complex II substrate K⁺-succinate (SUC) at physiological …

Diffuse Reflectance Spectroscopy Of Epithelial Tissue With A Smart Fiber-Optic Probe, Bing Yu, Amy Shah, Vivek K. Nagarajan, Daron G. Ferris

Biomedical Engineering Faculty Research and Publications

Diffuse reflectance spectroscopy (DRS) with a fiber-optic probe can noninvasively quantify the optical properties of epithelial tissues and has shown the potential as a cost-effective, fast and sensitive tool for diagnosis of early precancerous changes in the cervix and oral cavity. However, current DRS systems are susceptible to several sources of systematic and random errors, such as uncontrolled probe-to-tissue pressure and lack of a real-time calibration that can significantly impair the measurement accuracy, reliability and validity of this technology as well as its clinical utility. In addition, such systems use bulky, high power and expensive optical components which impede their …

Hemocompatibility Comparison Of Biomedical Grade Polymers Using Rabbit Thrombogenicity Model For Preparing Nonthrombogenic Nitric Oxide Releasing Surfaces, Hitesh Handa, Terry C. Major, Elizabeth Brisbois, Kagya Amoako, Mark E. Meyerhoff, Robert E. Bartlett

Mechanical and Industrial Engineering Faculty Publications

Nitric oxide (NO) is an endogenous vasodilator as well as natural inhibitor of platelet adhesion/ activation. Nitric oxide releasing (NOrel) materials can be prepared by doping an NO donor species, such as diazeniumdiolated dibutylhexanediamine (DBHD/N2O2), within a polymer coating. The inherent hemocompatibility properties of the base polymer can also influence the efficiency of such NO release coatings. In this study, four biomedical grade polymers were evaluated in a 4 h rabbit model of thrombogenicity for their effects on extracorporeal circuit thrombus formation and circulating platelet count. At the end of 4 h, Elast-Eon E2As was found to preserve 58% of …

Elucidation Of Emergent Regional Mechanisms Of Heart Muscle Dysfunction In The Mouse Model Of Duchenne Muscular Dystrophy, Ya-Jian Cheng

All Theses and Dissertations (ETDs)

Cardiac dysfunction is a primary cause of mortality in Duchenne Muscular Dystrophy (DMD), potentially related to elevated cytosolic calcium. However, the regional versus global functional consequences of cellular calcium mishandling have not been defined in the whole heart. Here, we elucidate, for the first time, loci- and age-dependencies between calcium mishandling and myocardial sheet function as a manifestation of dystrophin-deficient cardiomyopathy. We also map calcium transients to illustrate the regional dependence of ion flux disturbances in the dystrophin-deficient (mdx) mouse heart. Furthermore, we elucidate abnormalities in autophagic processes that can be corrected with nanoparticle therapeutics delivering rapamycin to heart tissues …

An Injectable, Calcium Responsive Composite Hydrogel For The Treatment Of Acute Spinal Cord Injury, Christopher A. Mckay, Rebecca D. Pomrenke, Joshua S. Mclane, Nicholas J. Schaub, Elise K. Desimone, Lee A. Ligon, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Immediately following spinal cord injury, further injury can occur through several secondary injury cascades. As a consequence of cell lysis, an increase in extracellular Ca²⁺ results in additional neuronal loss by inducing apoptosis. Thus, hydrogels that reduce extracellular Ca²⁺ concentration may reduce secondary injury severity. The goal of this study was to develop composite hydrogels consisting of alginate, chitosan, and genipin that interact with extracellular Ca²⁺ to enable in situ gelation while maintaining an elastic modulus similar to native spinal cord (∼1000 Pa). It was hypothesized that incorporation of genipin and chitosan would regulate hydrogel electrostatic characteristics …

Design Of Controlled Environment For Tissue Engineering, Malcolm Gerald Lapera

Master's Theses

Design of Controlled Environment for Tissue Engineering

Malcolm Lapera

Tissue engineering aims at relieving the need for donor tissue and organs by developing a process of creating viable tissues in the laboratory setting. With over 120,000 people awaiting a transplant, the need for generating tissue engineered organs is very large [3]. In order for organs to be engineered, a few issues need to be overcome. A work space that both creates an environment which maintains cell viability over an extended period of time as well as accommodates the necessary fabrication equipment will be needed to further tissue engineering research. Therefore, …

Modulation Of Leukocyte Infiltration And Phenotype In Microporous Tissue Engineering Scaffolds Via Vector Induced Il-10 Expression, R. Michael Gower, Ryan M. Boehler, Samira M. Azarin, Christine F. Ricci, Joshua N. Leonard, Lonnie D. Shea

Faculty Publications

Biomaterial scaffolds are central to many tissue engineering strategies as they create a space for tissue growth and provide a support for cell adhesion and migration. However, biomaterial implantation results in unavoidable injury resulting in an inflammatory response, which can impair integration with the host and tissue regeneration. Toward the goal of reducing inflammation, we investigated the hypothesis that a lentiviral gene therapy-based approach to localized and sustained IL-10 expression at a scaffold could modulate the number, relative proportions, and cytokine production of infiltrating leukocyte populations. Flow cytometry was used to quantify infiltration of six leukocyte populations for 21 days …

A Lensing Effect Of Inner Retinal Cysts On Images Of The Photoreceptor Mosaic, Christopher S. Langlo, John A. Flatter, Alfredo Dubra, William J. Wirostko, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Enhanced Glt-1 Mediated Glutamate Uptake And Migration Of Primary Astrocytes Directed By Fibronectin-Coated Electrospun Poly-L-Lactic Acid Fibers, Jonathan M. Zuidema, María C. Hyzinski-García, Kristien Van Vlasselaer, Nicholas W. Zaccor, George E. Plopper, Alexander A. Mongin, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioengineered fiber substrates are increasingly studied as a means to promote regeneration and remodeling in the injured central nervous system (CNS). Previous reports largely focused on the ability of oriented scaffolds to bridge injured regions and direct outgrowth of axonal projections. In the present work, we explored the effects of electro spun microfibers on the migration and physiological properties of brain astroglial cells. Primary rat astrocytes were cultured on either fibronectin-coated poly-l-lactic acid (PLLA) films, fibronectin-coated randomly oriented PLLA electro spun fibers, or fibronectin-coated aligned PLLA electro spun fibers. Aligned PLLA fibers strongly altered astrocytic morphology, orienting cell processes, actin …