Biomedical Engineering and Bioengineering Commons^™

Finite Element Study Of Transcranial Direct Current Stimulation: Customization Of Models And Montages, Dennis Q. Truong

Dissertations and Theses

Transcranial Direct Current Stimulation (tDCS) is a non-invasive neuromodulation technique that applies low amplitude current via electrodes placed on the scalp. Rather than directly eliciting a neuronal response, tDCS is believed to modulate excitability – encouraging or suppressing activity in regions of the brain depending on the polarity of stimulation. The particular application of tDCS is often determined by the electrode configuration and intensity of stimulation. MRI-derived finite element models have been developed to analyze the effect of these parameters allowing novel electrode configurations to be tested in subject specific models. By creating a subject specific model of an obese …

Application Of Computational Fluid Dynamics As A Simulation-Based Design Guide In A Microfluidic 3d Living Cell Array (3d Lca) Device, A.H. Rezwanuddin Ahmed

Dissertations and Theses

The use of computational fluid dynamics (CFD) as a tool in the aerodynamics and oil industry provides a reinforcement to efficiency in the design of aircrafts or for understanding the flow through pipes. A similar approach can be taken towards microfluidics, where traditionally devices have been designed based on experience or physiological replication, and a CFD simulation is shown post-manufacture to show the flow and diffusion patterns present. In this study, a reverse approach is suggested, by designing the device first in CFD and perform simulations on variations of alterable parameters to get insight on how the changing parameters affect …

Transport Pathway Across Hcaecs Uncer Convective Condtitions And The Role Of Apoptosis In Ldl Transport Through Hcaecs, Janpen Phupeerasupong

Dissertations and Theses

No abstract provided.

A Novel Biomaterial Enables Chemotactic Study Of Motile Central Nervous System-Derived Tumor Cells, Tanya Singh

Dissertations and Theses

"The local cell microenvironment plays an important role in maintaining the dynamics of the extracellular matrix (ECM) and the cell-ECM relationship. ECM is a complex network of macromolecules with distinct mechanical and biochemical characteristics [1]. The multifaceted interactions that occur between cells and the ECM are crucial to the regulation of processes that maintain homeostasis. These mechanisms are often deregulated during cancer onset and progression, which cause the ECM to become highly disorganized, alter the cell-matrix interactions, and promote increased hypervascularity and metastasis as these components are indicative of cancer progression. Medulloblastoma (MB) is one of the most common, malignant …

Design, Implementation, And Performance Study Of An Open Source Eye-Control System To Pilot A Parrot Ar.Drone Quadrocopter, John M. Ettikkalayil

Dissertations and Theses

Natural user interface is a fairly new concept in the field of human-computer interaction. It is the idea of using every day natural human behaviors and actions to control a device. An example of a natural user interface is touch control technology in smartphones, tablets, and new laptops. The interaction is more direct when compared to artificial input devices like a keyboard and mouse. Though natural user interface devices might not perform as well as standard input devices for certain applications, for other applications they are now the de facto standard. A new user interface that is poised to be …

A Dna Computer For Glioblastoma Multiforme Diagnosis And Drug Delivery, Sumaiya F. Hashmi

CMC Senior Theses

Glioblastoma multiforme (GBM) is a debilitating malignant brain tumor with expected patient survival of less than a year and limited responsiveness to most treatments, often requiring biopsy for diagnosis and invasive surgery for treatment. We propose a DNA computer system, consisting of input, computation, and output components, for diagnosis and treatment. The input component will detect the presence of three GBM biomarkers: vascular endothelial growth factor (VEGF), caveolin-1α (CAV), and B2 receptors. The computation component will include indicator segments for each of these genes, and ensure that output is only released if all the biomarkers are present. The output component …

Mechanics Of Hip Dysplasia Reduction In Infants Using The Pavlik Harness: A Physics Based Computational Model, Orlando Ardila, Eduardo Divo, Faissal Moslehy, George Rab, Alain Kassab, Charles Price

Mechanical Engineering - Daytona Beach

Biomechanical factors influencing the reduction of dislocated hips with the Pavlik harness in patients of Developmental Dysplasia of the Hip (DDH) were studied using a three-dimensional computer model simulating hip reduction dynamics in (1) subluxated and (2) fully dislocated hip joints. Five hip adductor muscles were identified as key mediators of DDH prognosis, and the non-dimensional force contribution of each in the direction necessary to achieve concentric hip reductions was determined. Results point to the adductor muscles as mediators of subluxated hip reductions, as their mechanical action is a function of the degree of hip dislocation. For subluxated hips in …

Rational Reprogramming Of Fungal Polyketide First Ring Cyclization, Yuquan Xu, Tong Zhou, Zhengfu Zhou, Shiyou Su, Sue A. Roberts, William R. Montfort, Jia Zeng, Ming Chen, Wei Zhang, Min Lin, Jixun Zhan, Istvan Molnar

Biological Engineering Faculty Publications

Resorcylic acid lactones (RAL) and dihydroxyphenylacetic acid lactones (DAL) represent important pharmacophores with heat shock response and immune system modulatory activities. The biosynthesis of these fungal polyketides involves a pair of collaborating iterative polyketide synthases (iPKSs): a highly reducing iPKS (hrPKS) whose product is further elaborated by a nonreducing iPKS (nrPKS) to yield a 1,3-benzenediol moiety bridged by a macrolactone. Biosynthesis of unreduced polyketides requires the sequestration and programmed cyclization of highly reactive poly-β-ketoacyl intermediates to channel these uncommitted, pluripotent substrates towards defined subsets of the polyketide structural space. Catalyzed by product template (PT) domains of the fungal nrPKSs and …

Design And Application Of An In Vivo Reporter Assay For Phenylalanine Ammonialyase, S. Wang, S. Zhang, T. Zhou, J. Zeng, Jixun Zhan

Biological Engineering Faculty Publications

Phenylalanine ammonia-lyase (PAL) is an important enzyme that links primary metabolism to secondary metabolism. Its efficiency is often a critical factor that affects the overall flux of a related metabolic pathway, the titer of the final products, and the efficacy of PAL-based therapies. Thus, PAL is a common target for metabolic engineering and it is of significant interest to screen efficient PALs for industrial and medical applications. In this study, a novel and efficient visible reporter assay for screening of PAL efficiency in Escherichia coli was established based on a plant type III polyketide biosynthetic pathway. The candidate PALs were …

Applications Of Antioxidant And Anti-Inflammatory Polymers To Inhibit Injury And Disease, David B. Cochran

Theses and Dissertations--Chemical and Materials Engineering

There is an undeniable link between oxidative stress, inflammation, and disease. Currently, approaches using antioxidant therapies have been largely unsuccessful due to poor delivery and bioavailability. Responding to these limitations, we have developed classes of polymer and delivery systems that can overcome the challenges of antioxidant and anti-inflammatory therapy. In our initial studies, nanoparticles of poly(trolox), a polymeric form of trolox, were surface-modified with antibodies. This modification allows for specific targeting to endothelial cells, affording controllable and localized protection against oxidative stress. We have shown these targeted nanoparticles bind, internalize, and provide protection against oxidative stress generation and cytotoxicity from …

A Novel Resistance Exercise Machine For Use In A Lower Body Negative Pressure Box To Counteract The Effects Of Weightlessness, Christine M. Dailey

Doctoral Dissertations and Master's Theses

Physiological deconditioning is a critical problem in space, especially during long-term missions. Resistance exercise coupled with lower body negative pressure (LBNP) has been shown to be effective in counteracting some of the deconditioning related problems. This thesis describes the development of a compact and effective resistance exercise machine that works within an existing environmentally controlled LBNP Box and is designed to simulate both exercise and sitting, to prevent microgravity-induced deconditioning by simulating physiological and biomechanical features of upright exercise and daily activities. Theoretical calculations are carried out to determine whether kinematics, musculoskeletal loadings, and metabolic rate during supine exercise within …

Mechanical Properties Of Human Amniotic Fluid Stem Cells Using Nanoindentation, Ashkan Aryaei, Ambalangodage Jayasuriya

Faculty Publications

The aim of this study was to obtain nanomechanical properties of living cells focusing on human amniotic fluid stem (hAFS) cell using nanoindentation techniques. We modified the conventional method of atomic force microscopy (AFM) in aqueous environment for cell imaging and indentation to avoid inherent difficulties. Moreover, we determined the elastic modulus of murine osteoblast (OB6) cells and hAFS cells at the nucleus and cytoskeleton using force–displacement curves and Hertz theory. Since OB6 cell line has been widely used, it was selected to validate and compare the obtained results with the previous research studies. As a result, we were able …

Biomechanics Of Porcine Renal Artery And The Development Of A Replacment Vessel, Mohamed Gabr

Theses and Dissertations

Mechanical characterization of biological soft tissues is essential in the field of biomedical engineering. In this study several loading experiments have been performed to efficiently characterize the passive mechanical response of both native porcine renal arteries and newly developed tissue constructs. The first aim of these studies is to determine whether there is a difference in mechanical response between the main renal artery and its first branch. After fitting the bi-axial data to a Holzapfel-type constitutive model, the results show that there is no statistical difference between the model parameters for renal artery and the first branch. The only significant …

3d Micron-Scale Imaging Of The Cortical Bone Canal Network In Human Osteogenesis Imperfecta (Oi), John R. Jameson, Carolyne Albert, Bjoern Busse, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Osteogenesis imperfecta (OI) is a genetic disorder leading to increased bone fragility. Recent work has shown that the hierarchical structure of bone plays an important role in determining its mechanical properties and resistance to fracture. The current study represents one of the first attempts to characterize the 3D structure and composition of cortical bone in OI at the micron-scale. A total of 26 pediatric bone fragments from 18 individuals were collected during autopsy (N_c=5) or routing orthopaedic procedures (N_OI=13) and imaged by microtomography with a synchrotron light source (SRµCT) for several microstructural parameters including cortical porosity …

Automated Detection Of Incomplete Exhalation As An Indirect Detection Of Auto-Peep On Mechanically Ventilated Adults, Nyimas Arief

Theses and Dissertations

Auto-PEEP is auto positive end-expiratory pressure due to excessive amounts of alveolar gas produced by sustained recurrent incomplete exhalation. Incomplete exhalation occurs when the exhaled breath never reaches a flow rate of 0 L/min. The objective of this dissertation is to develop an automated detection system of auto-PEEP through incomplete exhalation as revealed by ventilator graphics for mechanically ventilated adults. Auto-PEEP can cause adverse effects if allowed to linger and if not quickly identified. An automated detection system will be instrumental in helping to quickly identify auto-PEEP. A computerized algorithm was developed to detect incomplete exhalation based on the following …

Structured Materials For Catalytic And Sensing Applications, Selma Hokenek

USF Tampa Graduate Theses and Dissertations

The optical and chemical properties of the materials used in catalytic and sensing applications directly determine the characteristics of the resultant catalyst or sensor. It is well known that a catalyst needs to have high activity, selectivity, and stability to be viable in an industrial setting. The hydrogenation activity of palladium catalysts is known to be excellent, but the industrial applications are limited by the cost of obtaining catalyst in amounts large enough to make their use economical. As a result, alloying palladium with a cheaper, more widely available metal while maintaining the high catalytic activity seen in monometallic catalysts …

An Acoustic-Based Microfluidic Platform For Active Separation And Mixing, Myeong Chan Jo

USF Tampa Graduate Theses and Dissertations

Particle separation is of great interest to many biological and biomedical applications. Flow-based methods have been used to sort particles and cells. However, the main challenge with flow based particle separation systems is the need for a sheath flow for successful operation. Existence of the sheath liquid dilutes the analyte, necessitates precise flow control between sample and sheath flow, requires a complicated design to create sheath flow and separation efficiency depends on the sheath liquid composition. In addition, current gold standard active separation techniques are only capable of separation based on particle size; hence, separation cannot be achieved for same-size …

Fabricating And Characterizing Physical Properties Of Electrospun Polypeptide-Based Nanofibers, Dhan Bahadur Khadka

USF Tampa Graduate Theses and Dissertations

This dissertation has aimed to fabricate polypeptide based biomaterial and characterize physical properties. Electrospinning is used as a tool for the sample fabrication. Project focused on determining the feasibility of electrospinning of certain synthetic polypeptides and certain elastin-like peptides from aqueous feedstocks and to characterize physical properties of polymer aqueous solution, cast film and spun fibers and fiber mats. The research involves peptide design, polymer electrospinning, fibers crosslinking, determining the extent of crosslinking, fibers protease degradation study, fibers stability and self-organization analysis, structure and composition determination by various spectroscopy and microscopy techniques and characterization of mechanical properties of individual suspended …

Quantifying The Ergonomic Impact On Healthcare Workers Using A Needle-Free Injector Device, Humberto Jose Olivero Lara

USF Tampa Graduate Theses and Dissertations

Background: Jet injectors are advantageous over needle injectors by eliminating sharps hazards. The Government Accountability Office estimates 29% preventable sharp injuries with an estimated direct cost of more than $500 million out of the CDC's reported incidence of 385,000 needle stick injuries per year among US hospital healthcare workers. Yet the forces required to set and trigger devices using spring mechanisms for medication delivery have not been explored. This laboratory experiment measured forces exerted by healthcare workers (HCWs) using a particular jet injector approved by FDA in 2011.

Objectives: In order to quantify the ergonomic impact on HCWs using a …

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 …