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Theses/Dissertations

2014

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Articles 1 - 30 of 304

Full-Text Articles in Biomedical Engineering and Bioengineering

An Electrospinning Apparatus For The Production Of Heterogeneous Scaffolds And Their Application In Cartilage Regeneration, Andrew Ryan Hollingsworth Dec 2014

An Electrospinning Apparatus For The Production Of Heterogeneous Scaffolds And Their Application In Cartilage Regeneration, Andrew Ryan Hollingsworth

Theses

The human body contains a vast array of soft and hard tissues, each with their own unique set of physical, chemical, mechanical, and electrical properties. It is the combination of these tissues that allows the human body to function as it does. However, these tissues are subject to wear, fatigue, and injury and thus can potentially limit the functions of the body. Therefore, tissue engineering has sought various natural and synthetic materials that can be used for fabrication of cellular scaffolds that have the ability to promote cellular attachment, proliferation, differentiation, and eventual whole tissue formation for replacement and repair ...


Visualeyes 2020: A Software Suite To Integrate Instrumentation To Study The Near Triad Of Vergence, Stephen J. Lestrange Dec 2014

Visualeyes 2020: A Software Suite To Integrate Instrumentation To Study The Near Triad Of Vergence, Stephen J. Lestrange

Theses

A complete instrumentation suite has been constructed for use in a randomized clinical trial to be funded from the National Institute of Health and study the underlying potential mechanism(s) of vision therapy. This suite is designed to track rotation of each eye (vergence) as well as measure the lens power of the eye's lens (accommodation). The system is designed to dissect the near triad which is composed of the pupil constriction, vergence and accommodation. The visual targets are programmed to be shown on two sets of computer screens which allowed vergence, accommodation and proximal vergence cues to be ...


Fem Of Electrospinning Compared To Inkjet Printing Model, Maikel Ghaly Dec 2014

Fem Of Electrospinning Compared To Inkjet Printing Model, Maikel Ghaly

Theses

Electrospinning is a process that uses electrostatic forces to produce nanofibers, or fibers in the nano scale. Nanofibers are widely used in many fields like drug delivery and tissue engineering. Nowadays, it is gaining much attention in the research community as an advantageous process. However, there are many parameters that controlnanofiber formation. This research intends to develop a model of electrospinning on the basis of an inkjet printer technique by using a computer aided simulation (COMSOL). Inkjet printing is a technique that delivers small volumes at high repetitions which can betransported by electrostatic forces through the air onto their intended ...


Monitoring Of Cerebellar Injury Using Micro Ecog Signals In Ketamine/Xylazine Treated Rats, Gokhan Ordek Dec 2014

Monitoring Of Cerebellar Injury Using Micro Ecog Signals In Ketamine/Xylazine Treated Rats, Gokhan Ordek

Dissertations

Much of the cerebellar research has been conducted in anesthetized animals, particularly using ketamine/xylazine combination in rats, and yet the absolute impact of the anesthesia on the neural circuit remains unanswered . In the current study, spontaneous electrical activity and sensory evoked potentials from the cerebellar surface with chronically implanted, flexible-substrate, multielectrode arrays in rats were collected and analyzed with the motor cortex signals. The power spectra and the intercontact coherence plots of the spontaneous activity in the awake-quiet animals extended up to 800 Hz in the cerebellum and only up to 200 Hz in the motor cortex. Ketamine/xylazine ...


Real-Time Temperature Imaging Using Ultrasonic Change In Backscattered Energy, Weiyuan Zhao Dec 2014

Real-Time Temperature Imaging Using Ultrasonic Change In Backscattered Energy, Weiyuan Zhao

Engineering and Applied Science Theses & Dissertations

Thermal therapy from low-temperature cryosurgery to high-temperature ablation of tumors and unwanted electrical pathways has gained increased attention. Temperature imaging (TI) from magnetic resonance studies is the de facto standard for volumetric estimation of temperature. Ultrasound has the advantages of being cheap, portable, non-invasive and non-ionizing. Our group showed in predictions for single scatterers, simulations of scatterer populations and measurements in 1D, 2D and 3D, that CBE changed monotonically with temperature with 1oC accuracy. An obstacle to clinical application of CBE TI is estimation of temperature in real time, which is limited by time for motion compensation (MC ...


Experimental And Theoretical Studies Of Native And Engineered Vascular Tissue Mechanics, Boran Zhou Dec 2014

Experimental And Theoretical Studies Of Native And Engineered Vascular Tissue Mechanics, Boran Zhou

Theses and Dissertations

Background: Implantation of vascular grafts provides a means to restore blood flow in compromised regions of the circulatory system, and thus is used to treat a wide range of cardiovascular diseases. Despite significant advancements in autologous grafting strategies as well as the engineering of synthetic alternatives, mechanical, structural, and compositional incongruities between the graft and the host artery remain as contributing factors to graft failure. The typical failure modality manifests as proximal anastomotic intimal hyperplasia, which places restrictions on the host vessel size currently treated with grafting strategies (> 5 mm internal diameter). In order to improve long-term clinical outcomes, this ...


On The Application Of Mechanical Vibration In Robotics-Assisted Soft Tissue Intervention, Iman Khalaji Dec 2014

On The Application Of Mechanical Vibration In Robotics-Assisted Soft Tissue Intervention, Iman Khalaji

Electronic Thesis and Dissertation Repository

Mechanical vibration as a way of transmitting energy has been an interesting subject to study. While cyclic oscillation is usually associated with fatigue effect, and hence a detrimental factor in failure of structures and machineries, by controlled transmission of vibration, energy can be transferred from the source to the target. In this thesis, the application of such mechanical vibration in a few surgical procedures is demonstrated.

Three challenges associated with lung cancer diagnosis and treatment are chosen for this purpose, namely, Motion Compensation, tumor targeting in lung Needle Insertion and Soft Tissue Dissection:

  1. A robotic solution is proposed for compensating ...


A New Generation Of Polymer/Ceramic Composite Biomaterials For Bone Regeneration, Mehrnaz Salarian Dec 2014

A New Generation Of Polymer/Ceramic Composite Biomaterials For Bone Regeneration, Mehrnaz Salarian

Electronic Thesis and Dissertation Repository

There is a substantial emerging interest for fundamental and applied research on the reinforcement of polymeric materials using nanotechnology. In the biomedical industry, development of novel bone cement composite materials with enhanced mechanical properties is of tremendous potential importance. The most universally used injectable bone cement is made of poly(methyl methacrylate) (PMMA); however, the major disadvantage of PMMA is its non-biodegradability. Polymers such as poly(propylene fumarate) (PPF) and polycaprolactone (PCL) are biodegradable, but suffer from a lack of mechanical properties. The aim of this research was to test the efficacy of these biodegradable polymers integrating nanotechnology for the ...


Poly(Ester Amide) And Poly(Ethyl Glyoxylate) Nanoparticles For Controlled Drug Release, Amira Mohamed Moustafa Dec 2014

Poly(Ester Amide) And Poly(Ethyl Glyoxylate) Nanoparticles For Controlled Drug Release, Amira Mohamed Moustafa

Electronic Thesis and Dissertation Repository

The objective of this research was to develop polymeric nanoparticles (NPs) having improved drug release properties for drug delivery. Poly(ester amide)s (PEAs) are promising biodegradable polymers. PEA NPs were prepared via emulsification-evaporation and salting-out methods and optimized through by varying different processing parameters. Polymer-model drug conjugates based on PEAs containing L-aspartic acid and rhodamine B were synthesized and used for NP preparation. Release behavior was studied and compared to a control system with physically encapsulated rhodamine B. It was shown that the release of rhodamine B from the covalent system did not show the burst effect and exhibited ...


Digestion Of Municipal Wastewater Biosolids Using An Anaerobic Fluidized Bed Bioreactor (Anfbr), Zhenqi Wang Dec 2014

Digestion Of Municipal Wastewater Biosolids Using An Anaerobic Fluidized Bed Bioreactor (Anfbr), Zhenqi Wang

Electronic Thesis and Dissertation Repository

This research investigated the efficacy of the anaerobic fluidized bed bioreactor (AnFBR) technology in treating municipal wastewater sludges. Primary sludge (PS) and thickened waste activated sludge (TWAS) were studied in two lab-scale AnFBRs using High-density polyethylene (HDPE) as carrier media. PS was investigated at various organic loading rates (OLRs) ranging from 9 to 18 kg chemical oxygen demand (COD)/m3-d corresponding to hydraulic retention times (HRTs) of 2 to 4 days, with maximum COD and volatile suspended solid (VSS) removal efficiency of 70% and 72%, respectively. For TWAS, VSS destruction efficiency varied from 53% at an HRT of ...


Design Of A Haptic Interface For Medical Applications Using Magneto-Rheological Fluid Based Actuators, Nima Najmaei Dec 2014

Design Of A Haptic Interface For Medical Applications Using Magneto-Rheological Fluid Based Actuators, Nima Najmaei

Electronic Thesis and Dissertation Repository

This thesis reports on the design, construction, and evaluation of a prototype two degrees-of-freedom (DOF) haptic interface, which takes advantage of Magneto-Rheological Fluid (MRF) based clutches for actuation. Haptic information provides important cues in teleoperated systems and enables the user to feel the interaction with a remote or virtual environment during teleoperation. The two main objectives in designing a haptic interface are stability and transparency. Indeed, deficiencies in these factors in haptics-enabled telerobotic systems has the introduction of haptics in medical environments where safety and reliability are prime considerations. An actuator with poor dynamics, high inertia, large size, and heavy ...


Role Of Sensation In Altered Phalanx Grip Force In Persons With Stroke, Leah R. Enders Dec 2014

Role Of Sensation In Altered Phalanx Grip Force In Persons With Stroke, Leah R. Enders

Theses and Dissertations

Many individuals experience hand impairment after stroke leading to decreased ability to perform daily living activities. Previous research studies have investigated how stroke survivors' pinch grip control differs from healthy individuals, even though many individuals can only grasp with power grip after stroke. Furthermore, many stroke survivors experience tactile sensory deficit in their paretic limb in addition to motor deficit. It is currently unknown how stroke induced tactile sensory deficit affects power grip force directional control, which is important in terms of preventing object slippage and power grip normal force generation. Additionally it is unknown if power grip could be ...


An Optogenetic Brain-Machine Interface For Spatiotemporal Neuromodulation, Ryan Andrew Baumgartner Dec 2014

An Optogenetic Brain-Machine Interface For Spatiotemporal Neuromodulation, Ryan Andrew Baumgartner

Theses and Dissertations

Direct neural stimulation has recently become a standard therapy for neurological disorders such as Parkinson's Disease, Essential Tremors, and Dystonia. Currently, deep brain electro-stimulation and neuro-pharmaceutical treatments are the dominant therapeutic options available to the public. As our understanding of brain function and neurological diseases improves, we are able to develop more advanced neuromodulation techniques. These methods could become viable treatment solutions for treating brain dysfunction. Optogenetics, first introduced by a research team led by Karl Deisseroth at Stanford University, has proved to be a versatile technique with remarkable potential to be used in treatments for brain disorders, dysfunction ...


Single Cell Biophysics: Applications In Cardiomyocyte Mechanobiology And Stem Cell Mechanotransduction, Benjamin Edward Reese Dec 2014

Single Cell Biophysics: Applications In Cardiomyocyte Mechanobiology And Stem Cell Mechanotransduction, Benjamin Edward Reese

Doctoral Dissertations

While a great deal of work has been done to analyze cardiac dynamics and mechanics at the organ and tissue levels, there remains much less data regarding these metrics at the single cell level. Additionally, as fields such as regenerative medicine and tissue engineering are beginning to demonstrate greater therapeutic potential, the study and influence of stem cell mechanics on differentiation has become a major area of interest. For these reasons, along with the continued advancement of molecular techniques and assays, there is a growing need to develop functional assays that can integrate and bridge the findings from multiple length ...


Biomechanical Joint Demands And Functional Outcomes During Manual Wheelchair Use In Pediatric Patients With Spinal Cord Injury, Christine M. Aurit Dec 2014

Biomechanical Joint Demands And Functional Outcomes During Manual Wheelchair Use In Pediatric Patients With Spinal Cord Injury, Christine M. Aurit

Theses and Dissertations

The biomechanical demands of the upper extremities (UEs) during pediatric manual wheelchair (MWC) use have not been fully explored. Children who use MWCs for mobility engage in a range of functional activities that may place large biomechanical demands on the UEs leading to a high risk on overuse injuries. This study aims to analyze the kinematics and kinetics of pediatric manual wheelchair use during propulsion, starting, stopping and weight relief tasks. Fourteen pediatric patients with spinal cord injury were recruited and data were collected using a 14-camera Vicon MX motion analysis system (Oxford Metric Group, Oxford, UK) and a SmartWheel ...


Induction Of Differentiation Of Dental Pulp-Derived Mesenchymal Stem Cells (Dpsc), Aubrey Young Dec 2014

Induction Of Differentiation Of Dental Pulp-Derived Mesenchymal Stem Cells (Dpsc), Aubrey Young

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mesenchymal stem cells are derived from a variety of human tissues and are being bioengineered and studied for possible uses in the advancement of medicine. Recent efforts are being focused on Dental Pulp Stem Cells (DPSC's) due to the accessibility of this tissue. Many factors influence DPSC quality and quantity, including the specific methods used to isolate, collect, concentrate, and store these isolates once they are removed. Ancillary factors, such as the choice of media, the selection of early versus late passage cells, and cryopreservation techniques may also influence the differentiation potential and proliferative capacity of DPSC isolates.

The ...


Adaptation And Validation Of An Analytical Localized Muscle Fatigue Model For Workplace Tasks, John Maurice Looft Dec 2014

Adaptation And Validation Of An Analytical Localized Muscle Fatigue Model For Workplace Tasks, John Maurice Looft

Theses and Dissertations

Muscle fatigue is universally experienced in daily life, from recreational physical activity to the workplace. However, our ability to estimate fatigue is limited. Several attempts have been made to mathematically model the effects of fatigue, such as how long a muscle contraction may be sustained, known as `endurance time.' However, these simple models of endurance time are limited to static contractions when the body is not moving, but muscles are contracted. This research aims to advance a previously proposed analytical model of muscle fatigue to represent complex tasks such as with rest intervals and dynamic contractions. Multiple methodologies were employed ...


3d Differentiation Enhances The Efficiency Of Differentiation Of Human Induced Pluripotent Stem Cells To Insulin Producing Cells, Pavana Gururaj Rotti Dec 2014

3d Differentiation Enhances The Efficiency Of Differentiation Of Human Induced Pluripotent Stem Cells To Insulin Producing Cells, Pavana Gururaj Rotti

Theses and Dissertations

Type 1 Diabetes (T1D) is an autoimmune disorder in which the pancreatic β-cells are destroyed by the body's immune system. The reduced number of β-cells leads to inadequate insulin secretion and high glucose levels in the body. The requirement of insulin injection throughout life and lack of donors for islet transplantations has prompted a search for more accessible and available sources of insulin producing cells that can be transplanted in T1D patients. To that end, the discovery of induced pluripotent stem (iPS) cells has provided a potential source of precursors for cell therapy for T1D. iPS cells are reprogrammed ...


Smooth Muscle Cell Organization In The Stem Region Of The Gracilis Collateral Circulation In Balb/C Mice, Laura Lenae Burckhardt Dec 2014

Smooth Muscle Cell Organization In The Stem Region Of The Gracilis Collateral Circulation In Balb/C Mice, Laura Lenae Burckhardt

Biomedical Engineering

Of the approximately 8 million Americans who suffer from ischemic peripheral arterial occlusive disease (PAOD), many present with intermittent claudication, or pain associated with exercise. Impaired vasodilation of resistance vessels is a potential explanation for this symptom. Occluded arteries can lead to increased flow through collateral vessels, which function as natural bypasses around the obstruction. This increase in blood flow and resulting shear stress can cause outward remodeling, or arteriogenesis, which improves the efficacy of collaterals. However, following femoral artery ligation in a mouse model of chronic ischemia, vasodilation in the stem region of collateral vessels is impaired at day ...


Designing A Biomimetic Testing Platform For Actuators In A Series-Elastic Co-Contraction System, Ryan Tyler Schroeder Dec 2014

Designing A Biomimetic Testing Platform For Actuators In A Series-Elastic Co-Contraction System, Ryan Tyler Schroeder

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actuators determine the performance of robotic systems at the most intimate of levels. As a result, much work has been done to assess the performance of different actuator systems. However, biomimetics has not previously been utilized as a pretext for tuning a series elastic actuator system with the purpose of designing an empirical testing platform. Thus, an artificial muscle tendon system has been developed in order to assess the performance of two distinct actuator types: (1) direct current electromagnetic motors and (2) ultrasonic rotary piezoelectric motors. Because the design of the system takes advantage of biomimetic operating principles such as ...


Unlocking The Secrets Of Multi-Flagellated Propulsion, Stefan Oma Nwandu-Vincent Dec 2014

Unlocking The Secrets Of Multi-Flagellated Propulsion, Stefan Oma Nwandu-Vincent

Doctoral Dissertations

In this work, unique high-speed imaging platforms and an array of theoretical analysis methods are used to thoroughly investigate eukaryotic multi-flagellated propulsion using Tritrichomonas foetus as a test case. Through experimental observations through our imaging system with superior resolution and capture rate exceeding that of previous studies, it was discovered for the first time that the T. foetus employs a strategy similar to that of the “run and tumble” strategies found in bacteria and Chlamydomonas; it has two distinct flagellar beating patterns that result in two different body swimming motions, linear and turning swimming.

These two flagella patterns were ...


Development Of A Novel Device For The Perfusion Driven Decellularization Of Skeletal Muscle, Benjamin Kasukonis Dec 2014

Development Of A Novel Device For The Perfusion Driven Decellularization Of Skeletal Muscle, Benjamin Kasukonis

Theses and Dissertations

Decellularization of skeletal muscle is a process that removes cellular components of skeletal muscle tissue while leaving behind the intact extracellular matrix (ECM). Skeletal muscle ECM is currently being studied as a biologic scaffold for repairing volumetric muscle loss (VML) because the removal of cells greatly reduces the antigenicity of the donor tissue. Decellularization usually relies on passive diffusion of detergents, surfactants and/or osmotic solutions to strip cells from the ECM. However, passive diffusion alone is usually not sufficient for complete removal of cells from the interior of large pieces of skeletal muscle using detergents, such as sodium dodecyl ...


Fabrication And Characterization Of Antioxidant Loaded Liposomes., Brian Gettler Dec 2014

Fabrication And Characterization Of Antioxidant Loaded Liposomes., Brian Gettler

Electronic Theses and Dissertations

Radiation exposure is both a major obstacle in space exploration and an occupational hazard for various careers causing DNA damage and ROS. In order to reduce the effects of radiation, the primary and most explored approach has been focused around mitigation in terms of exposure duration, exposure intensity, and shielding usage. In some situations none of these reduction strategies were viable and so the use of antioxidants is being explored as an alternate strategy for therapeutic purposes. One such antioxidant is curcumin, otherwise known as diferuloylmethane, is a component of turmeric with both antioxidant properties and anti-inflammatory properties. Another antioxidant ...


Development And Characterization Of An Autologous Whole Cell Breast Cancer Vaccine, Samantha Leigh Kurtz Dec 2014

Development And Characterization Of An Autologous Whole Cell Breast Cancer Vaccine, Samantha Leigh Kurtz

Theses and Dissertations

Approximately 40,000 women will die from breast cancer in the United States in 2014. About 90% of these deaths will be due to metastases, rather than the primary tumor and majority of metastases are due to the recurrence and progression of non-metastatic disease. Current adjuvant treatments, such as chemotherapy and radiation, have severe side effects and may result in overtreatment and drug resistance.

Since greater than 90% of patients are diagnosed between stages I-III and have minimal residual disease after treatment, there is an opportunity to treat patients with an autologous breast cancer vaccine. Autologous vaccines under development have ...


Development Of A Heart Rate Variability Measurement System Using Embedded Electronics, Naresh Kumar Velmurugan Dec 2014

Development Of A Heart Rate Variability Measurement System Using Embedded Electronics, Naresh Kumar Velmurugan

Theses and Dissertations

Recent advances in embedded electronics have a remarkable influence on the health care system. One of the most important applications is to monitor the health care of the patients at anytime and anyplace. In the last two decades, many researchers have focused mainly on heart rate variability (HRV) measurements. Patient's heart rate variability should be continuously monitored to help them in case of emergency. Under these circumstances, patients are required to have a HRV measuring kit for a constant observation.

The proposed project focuses on the development of a heart rate variability measurement system with the use of embedded ...


A Low-Power Approach For Front End Biological Signal Conditioning, Logan Smith Taylor Dec 2014

A Low-Power Approach For Front End Biological Signal Conditioning, Logan Smith Taylor

Masters Theses

In a lab-on-a-chip (LOC) application, the measurement of small analog signals such as local temperature variation often involves detection of very low-level signals in a noisy micro-scale environment. This is true for other biomedical monitoring systems as well. These systems observe various physiological parameters or electrochemical reactions that need to be tracked electrically. For temperature measurement pyroelectric transducers represent an efficient solution in terms of speed, sensitivity, and scale of integration, especially when prompt and accurate temperature monitoring is desired.

The ability to perform laboratory operations on a small scale using miniaturized LOC devices is a promising biosensing technique. The ...


A Portable Impedance Biosensing System Based On A Laptop With Labview For Rapid Detection Of Avian Influenza Virus, Yixiang Wang Dec 2014

A Portable Impedance Biosensing System Based On A Laptop With Labview For Rapid Detection Of Avian Influenza Virus, Yixiang Wang

Theses and Dissertations

Avian Influenza Virus (AIV) H5N1 is a highly pathogenic virus found not only in birds but also in human. Rapid and sensitive detection method is needed to help prevent the spread of AIV H5N1. In this study, a portable impedance biosensing system based on a laptop with LabVIEW software was developed for detection of AIV H5N1. First, a virtual instrument was programmed with LabVIEW software to form a platform for impedance measurement, data processing and control. The audio card of a laptop was used as a function generator while a data acquisition card was used with the signal channels for ...


Fabrication, Testing And Analysis Of A Fatigue Sensor For Structural Health Monitoring, Subash Gokanakonda Dec 2014

Fabrication, Testing And Analysis Of A Fatigue Sensor For Structural Health Monitoring, Subash Gokanakonda

Dissertations

A novel fatigue monitoring sensor (FMS) is designed, fabricated and tested for detecting and monitoring the fatigue damage and estimating the remaining life of structures and components subjected to cyclic loads. The concept is based on the characteristics of stress / strain life cycle relationship of engineering materials. Sensor consists of alternate slots and strips having different strain magnification factor with respect to the nominal strain. The sensor is designed in such a way that the strips will experience the strain which closely resemble the actual strain distribution in the notch or critical area of the component. The sensor can be ...


Comparative Analysis Of Clavicular Tunnel Confìguration For Coracoclavicular Ligament Reconstruction, Mark Omwansa Dec 2014

Comparative Analysis Of Clavicular Tunnel Confìguration For Coracoclavicular Ligament Reconstruction, Mark Omwansa

Master's Theses

A number of coracoclavicular ligament reconstructions are carried out each year and post surgical fractures of the clavicle have been reported. The primary objective of this research is to develop a comparative metrics that compares clavicular tunnel configurations used in coracoclavicular reconstruction techniques. The goal of this comparison is to reduce post surgical failures due to clavicle fractures. The present analysis compared two techniques { a single 3 mm clavicular tunnel and the other double 6 mm tunnels { experimentally, using Four-point bending testing and Finite Element Analysis (FEA). A unique method, slicing, was used to create an FE clavicle mesh model ...


Development Of A Transport System For Advancing Tissue Engineering And Cell Identification, Suzanne Mae Tabbaa Dec 2014

Development Of A Transport System For Advancing Tissue Engineering And Cell Identification, Suzanne Mae Tabbaa

All Dissertations

This work centers on the development of a novel passive transport system for two tissue engineering applications – cell distribution and cell separation. This approach relies on a wicking fiber-based system, derived from the textile field that functions by directing and maintaining transport of cells as well as fluids and biomolecules. This system has the ability to enhance cell movement for both the purpose of cell seeding distribution as well as to isolate specific cell types from heterogeneous cell populations.

The success of spinal fusions and large bone defects is often limited by the decreased surrounding vasculature and the ability of ...