Biomedical Engineering and Bioengineering Commons^™

Elastic Degradable Polyurethanes For Biomedical Applications, Changhong Zhang

All Theses

Several series of polyurethanes were synthesized with linear or crosslinked structures by using different synthesis routes. Two studies are mentioned: (1) the synthesis of degradable polyurethanes with linear structure and the investigation of the elasticity and cytophilicity of the materials as function of the chain extender, and (2) the synthesis and the investigation of the biocompatibility, degradation, hydrophilicity and mechanical properties of the polyurethane-based hydrogels with crosslinked structure.

Validation Of An Inertial Sensor System For Quantifying Knee Function, Aaron Koslin

All Theses

Gait analysis has become a useful tool for clinicians in evaluating the progression of pathologies through functional analysis. The high cost and dedicated laboratories associated with the traditional camera-based motion analysis systems present the need for an alternative system. Direct measurement of kinetic parameters using inertial sensors (gyroscopes and accelerometers), in place of indirect calculations from position data obtained using cameras, has been shown effective in resolving important gait parameters.
In order to directly compare gait parameters obtained using inertial sensors and a camera system, data was simultaneously collected from both systems for seven test subjects during normal gait. Three …

Tannic Acid Crosslinked Collagens And Potential For Breast Tissue Engineering, Cheryl Parzel

All Theses

The purpose of this study was to develop and assess a potential key feature in a minimally-invasive breast reconstruction device and to collect information for an in vitro tissue test system. Tannic acid is a hydrolysable plant tannin, and it has been determined that tannic acid functions as a collagen crosslinking agent through both hydrogen bonding mechanisms and hydrophobic effects. Additionally, current research suggests that tannic acid may have anti-tumor properties. Therefore, it has been proposed that tannic acid can be used as an agent to induce apoptotic processes in any transplanted adult stem cells that are inclined to spontaneously …

Development Of A Cellular Fiber Spinning Technology For Regenerative Medicine, Willie Jones

All Theses

In order to prove that our textile hollow fiber spinning apparatus was adequate for cellular encapsulation, we confirmed the viability and metabolic activity of green fluorescent protein (GFP) labeled bovine mammary epithelial cells (MAC-Ts) that were encapsulated in either the wall or lumen of alginate fibers. After a 21 day in vitro macroscopic evaluation, no decrease in fluorescence was observed; and it was determined that MAC-Ts encapsulated under both methods produced lactic acid and consumed glucose. Histomorphological analyses revealed that the diameter of the MAC-Ts increased under both encapsulation scenarios, with little to no evidence of cell cluster propagation. Based …

Tribological Systems For The Evaluation Of Supercritical Carbon Dioxide Sterilized Ultra-High Molecular Weight Polyethylene, John Desjardins

All Dissertations

Polymeric biomaterials are especially susceptible to changes in mechanical and surface material properties as a result of sterilization processes that involve heat, moisture and/or irradiation. This is problematic for polymeric materials used in total joint replacement bearings, as these constructs must retain their superior mechanical and tribological properties over their expected 10-20 years of implantation. A younger more active patient population has now exacerbated this longevity issue with service lifetimes of 20+ years now being expected. Supercritical phase carbon dioxide (SC-CO2) is an industrial solvent that has shown great promise as a sterilizing agent in the food industry. Recently, SC-CO2 …

Stabilization Of Vascular Elastin By Treatment With Tannins, Jason Isenburg

All Dissertations

Elastin is an important component of the extracellular matrix that endows cardiovascular tissue with the ability to extend and recoil repetitively. It has been shown that elastin may be vulnerable to enzymatic degradation and calcification in certain pathological cases. As a result, elastin degeneration may be associated with the failure of tissue-derived cardiovascular devices, such as bioprosthetic heart valves, as well as the development and progression of aortic aneurysms, a disease associated with progressive connective tissue degeneration of the arterial wall. Therefore, an elastin stabilizing agent may be beneficial for both applications. As such, our objectives for elastin stabilization are …

Soccer Headgear Effects On Impact Profiles During A Heading Scenario, Ryan Posey

All Theses

The risk of head injuries in the sport of soccer has recently become a topic of concern, particularly with youth players whom may suffer long-lasting or even permanent effects from a severe head injury. In response to these worries, headguards have been developed specifically for use in soccer. These headguards have been studied using crash test dummy heads mounted with various electronic instruments - accelerometers, gyroscopes, etc. The headgear-mounted dummy heads have been struck with various objects (soccer ball, another dummy head, pole, etc) to test for changes in head acceleration response.
Testing of soccer headgear has previously been limited …

Fluorescent Enzymatic Smart Tattoos Comprising Hybrid Silicate Microparticles, Metalloporphyrin Complexes, And Mass Transport-Limiting Nanofilms, Erich Wayne Stein

Doctoral Dissertations

Diabetics are often required to self-monitor blood glucose levels to effectively deliver prescribed therapies. However, the pain and bother associated with traditional finger-prick measurements often result in decreased patient compliance and therefore poor disease management, which could result in the early-onset of complications. Enzymatic "smart tattoos"—implantable luminescent particles that may be transdermally interrogated with light—are being pursued as minimally-invasive diabetic monitoring devices, with hopes of increasing diabetic compliance by reducing excessive pain and bother associated with finger-prick measurements. These devices typically comprise an oxygen-quenched luminescent dye and glucose oxidase (GOx), an enzyme that catalyzes the oxidation of β-D-glucose. Under glucose-limited …

Characterization Of Hypertension Through Multivariate Analysis Utilizing Linear And Nonlinear Methods, Diane L. Donnelly

Dissertations

Analysis of blood pressure by nonlinear methods is vastly underutilized in current research. As such, 24-hour ambulatory blood pressure data from a small cohort of borderline hypertensive and normotensive subjects were analyzed using linear and nonlinear methods. Data were collected and provided by researchers from Columbia University. The cohort size was twelve subjects, consisting of two groups of six each. Although disease state was known, group membership for individual subjects was not. Therefore, one aspect of this research was to separate the cohort, a-priori, into two distinct, evenly sized groups, based solely on analysis results. Separation was accomplished by the …

Individual Cell Pressure Control In An Air Mattress For The Prevention Of The Pressure Sores, Kapilchandra Anand

Theses

Many kinds of pressure-relieving mattresses have been developed to prevent pressure sores in patients with spinal cord injuries (SCIs) and obesity. Current technology uses alternating air pressure mattress, foam and low pressure mattress for reducing the incidence of pressure sores in SCI and obesity patients. These mattresses do not have control of pressure in individual air chambers. They are open loop system and they do not receive any feedback from the system. They have at the most control of two different pressures. The purpose of this study is to improve the current assistive technology in reducing pressure sores and to …

In-Vitro Characterization Of Boronized Titanium Alloy By Means Of Corrosion And Electrochemical Impedance Spectroscopy Methods In Simulated Body Fluids, David Anthony Panus

Theses

Titanium and titanium alloys are becoming the backbone of medical implants and prosthetics. Titanium alloys are used because of its high biocompatibility and similarity to bone. However, titanium and titanium alloys have a low wear resistance. Titanium and titanium alloys are susceptible to particle erosion, which can cause inflammation, infection, and even implant rejection. Boronizing titanium alloy improves titanium's wear resistance and also improves corrosion resistance.

The target of this research was to characterize the corrosion characteristics of both unboronized and boronized titanium using both electrochemical corrosion methods and Electrochemical Impedance Spectroscopy (ELS) in simulated body fluid. Using electrochemical methods …

Fabrication Of Hydroxyapatite-Biodegradable Polymer Scaffolds By Electrospinning For Potential Bone Tissue Application, Satomi Suzuki

Theses

The purpose of this study is to determine the potential of combining hydroxyapatite (HA) and polymers to form synthetic composite materials used for bone tissue engineering applications. In this study, ceramic-biodegradable polymer composites are fabricated by electrospinning method. The biodegradable polymers used are poly(L-lactic acid) (PLLA), and poly(lactide-co-glycolide) (PLGA). Two types of HA-polymer solutions are first prepared to achieve HA weight percentage of 0, 10, and 25%of the total combined weight of HA and PLLA, and HA and PLGA. The solutions are electrospun to form nanofibrous mats incorporated with HA powder. A biomimetic process was also conducted as a …

Environmental Effects On Driver Acceleration Exposure, Shekhar Khanal

Masters Theses

The European Union has developed a set of standard for the exposure to whole body vibration measured by acceleration. For manufacturers to meet this directive, it is essential to understand the levels of exposures that are common among long-haul vehicle drivers.

Many factors can influence the exposure levels. Generally, all the European vehicles are the cab-over design. Each vehicle manufacturer has provided a combination of truck and cab suspensions in addition to the air-ride seating that is standard on the vehicles. The road quality, driver speeds, and time of daily work can have variation from country to country. The determination …

Molecular Modeling Of Proteins And Peptides Related To Cell Attachment In Vivo And In Vitro, Wanhua Zhao

Doctoral Dissertations

Polypeptides constitute half of the dry mass of the cell, they form the bulk of the extracellular matrix (ECM), and they are a common element of extra- and intracellular signaling pathways. There is increasing interest in the development of computational methods in polypeptide and protein engineering on all length scales. This research concerns the development of computational methods for study of polypeptide interactions related to cell attachment in vivo and in vitro.

Polypeptides are inherently biocompatible, and an astronomical range of unique sequences can be designed and realized in massive quantities by modern methods of synthesis and purification. These …

Osteogenic Differentiation Of Human Mesenchymal Stem Cells On Thin Film Tyrosine Derived Polycarbonates, Tamunotoyne Briggs

Theses

Mesenchymal stem cells, harvested from adult bone marrow, are promising in the field of regenerative medicine because of the vast differentiation potential into various cell lines such as: osteoblasts, chondrocytes, adipocytes, and neurons. Osteogenic differentiation of human mesenchymal stem cells (hMSC) could be an important tool in the treatment of orthopedic deficiencies such as bone defects. The extent of in vitro human mesenchymal stem cell growth, adhesion, motility and differentiation into osteoblasts is a function of the material surface chemistry which is mediated by protein adsorption onto the surface. A library of tyrosine derived polycarbonates allows the tailoring of material …

Auto Detection In Autism, Gayathri Chandar

Theses

Autism is a neurobiological disorder in which, certain regions of the brain are affected. The main features of autism are impairment in communication, social interaction, language and deficit in imitation and theory of mind. Using Functional Magnetic Resonance Imaging (fMRI), haemodynamic responses during a bilateral finger tapping task are analyzed for both autistic subjects and normal control subjects. fMRI is a noninvasive technique to image the activity of the brain related to a specific task. Generally, the active voxels in the IMRI images are detected using parametric or non-parametric statistical methods in which the fMRI response is assumed to have …

Pda Based Ambulatory Pulse Oximeter, Arpita Shah

Theses

The main aim of the research was to develop an ambulatory pulse oximeter which can be used to monitor the SpO₂ heart rate (HR) and plethsymograph (PPG) waveform of a person. To achieve this, an algorithm was developed in LabVIEW 8.0 to extract the HR, SpO₂ and PPG data from a Nonin Xpod device, Nonin Medical, Inc. LabVIEW PDA software was developed to make it compatible with the PDA. LabVIEW software was also developed for sending the data to the PDA via Bluetooth Pulse Oximeter commercialized by Nonin Medical Company.

Using this algorithm, data was collected from three …

The Complex Behavior Of Poly(Dte) Carbonate And Its Blend Properties, Christopher George Elvin

Theses

Over the years a number of different polymers have been studied for bone applications. Polyesters such as the poly lactic acids (PLA), poly glycolic acids (PGA), and their copolymers have been studied intensely for bone regeneration purposes. Poly(DTE)carbonate has been found useful for bone regenerative purposes and is under review by the U.S. Food and Drug Administration.

The purpose of this study was to investigate the properties of poly(DTE)carbonate when PLLA, PLGA, and P(LcoDL)LA was blended with it. The desired outcome was to produce miscible polymer blends or significant phase shift in the blended materials which will make them at …

Automatic Detection Of Qt And Related Intervals, Divya Gowdar

Theses

The objective of this thesis is divided into two main sections: The first section comprises of the development of the algorithm for the detection of the Q wave, Tmax afld the Tend to measure the intervals such as QT, QT corrected (QTc), RT, QT_max and RT_max respectively. The second section deals with the analysis of different variabilities including heart rate variability (HRV), QT, QTc, RT, QT_max and RT_max.

Using the R wave points as reference points, the Q wave was detected by using the Differential Threshold Method (DTH). The Tmax was detected by using a …

Fabrication Of Aligned Nanofiber Yarns, Mats And Isolation Of Single Nanofiber In Electrospinning, Venkatesh T. Nathilvar

Theses

Electrospinning has been extensively used as an effective technique for the fabrication of submicron and nanometer scale polymeric fibers. In spite of technological advances in electrospinning, creating a highly aligned fiber structure is a tough target to be achieved because of the chaotic motion of the electrospinning jet. In this study, two different techniques have been adopted to form a highly aligned nanofibrous scaffolds. Using these methods highly aligned fiber yams and mats are produced from Cellulose Acetate (CA) in a mixed solvent of acetone and water. In both the techniques the nanofibers suspend over the gap in a highly …

Development Of A System To Measure Cardiac Function In The Drosophila Melanogaster Animal Model, Heather Anne Reinhardt

Theses

Previous studies have shown that several genes are evolutionarily conserved from lower organisms to man, where a number of genes have been directly linked to cardiac function and disease. The Drosophila melanogaster (Fruit Fly) has a genome similar to humans and therefore has proven to be an important animal model to study the role of genetics in cardiac function and disease development. Fruit flies are an important basic science model because of the ease with which genes can be manipulated and quickly expressed due to the short lifespan of the fly. Although standard techniques exist to affect the genome of …

Possibilities Of Glutamate-Mediated Synaptic Like Activity In Somatosensory Mechanoreceptors Such As Pacinian Corpuscles?, Kevin Kopko

Honors Capstone Projects - All

Pacinian Corpuscles (PCs) are somatosensory mechanoreceptors, composed of a central neurite, surrounded by layers of lamellae that make up the inner core, which are specialized glial cells, and fibroblast derived outer-core lamellae of the surrounding capsule. Several components specific to a chemical synapse (Vglut1, Vamp1, SNAP-23) were localized to both the neurite and the inner-core cells in feline mesenteric PCs using immunocytochemistry. However, it has long been postulated that the first synapse of the PC occurs at the dorsal column nuclei, or spinal cord, and that no classical synapse is present in the distal ending of the capsulated receptor. While …

Predictive Measures Of Tooth/Tooth Contact In Mastication, Elizabeth Klodd

Honors Capstone Projects - All

Understanding the process of mastication, or chewing, is very important in humans. Understanding the way people chew can help craniofacial repair to victims of accidents or other conditions. Stages of chewing and swallowing have been categorized; however, it is currently unknown when exactly the teeth meet during mastication. Vertical motion data were obtained from seven subjects while chewing food of different consistencies. A videofluorograph collected the data and they were manipulated in Excel to be plotted as time vs. vertical displacement for the upper incisor tooth. The first and second derivatives of these motion-time charts were taken in order to …

Development Of Self-Assembled Monolayer-Based Cell Culture Platform Towards Fabrication Of A Three-Dimensional Bioreactor, Rajendra Kandoor Aithal

Doctoral Dissertations

The extracellular matrix (ECM) plays an important role in regulating a number of cellular properties and functions like cell differentiation, cell synthesis and degradation, cell viability and proliferation, cell function, and cell aging. Surface modification of planar substrates with self-assembled monolayers (SAMs) is a promising technique to achieve stable ECMs.

In this work, substrates such as silicon (Si), gallium arsenide (GaAs) and indium tin oxide (ITO) substrates were modified with SAMS containing amino (-NH2), methyl (-CH3), thiol (-SH) and carboxylic (-COOH) end groups and characterized using contact angle measurements, surface infrared (IR) spectroscopy and atomic force microscopy (AFM). Different cell …

Biological System Impedance Identification Using Stochastic Estimation And Control, Enrique Mendezaceves

Theses and Dissertations

In an effort to find a less invasive way of testing for different cell abnormalities and finding more practical tests for different cellular mutations, this project makes use of a well-known technique called cellular impedance spectroscopy coupled with stochastic estimation. Impedance spectroscopy, the measurement of the complex resistance of a biological body, is not a new technology; it has been around for many years and has been used to make electrical representations of different biological systems. The problem with this procedure is that models cannot be used for system identification. Stochastic estimation can complement a model produced by analyzing the …

Quantitative Object Reconstruction Using Abel Transform Tomography And Mixed Variable Optimization, Kevin R. O'Reilly

Theses and Dissertations

Researchers at the Los Alamos National Laboratory (LANL) are interested in quantitatively reconstructing an object using Abel transform x-ray tomography. Specifically, they obtain a radiograph by x-raying an object and attempt to quantitatively determine the number and types of materials and the thicknesses of each material layer. Their current methodologies either fail to provide a quantitative description of the object or are generally too slow to be useful in practice. As an alternative, the problem is modeled here as a mixed variable programming (MVP) problem, in which some variables are nonnumeric and for which no derivative information is available. The …

Medical Equipment Planning And Construction Of A Interventional Neuroradiology Suite, Furqan Elahi

Theses

New York-Presbyterian Hospital is one of the most comprehensive university hospitals in the world, with leading specialists in every field of medicine. It is composed of two renowned medical centers, New York-Presbyterian Hospital/Columbia University Medical Center and New York-Presbyterian Hospital/Weill Cornell Medical Center. The hospital's strategic planning group identified the need to expand the Interventional Neuroradiology service that the hospital provides. This brought upon the need to form a committee to plan the construction of an Interventional Neuroradiology. The problem statement of this thesis is to prepare a best practices guideline from a clinical engineering perspective on constructing the three …

Impact Of Missed Beats On Heart Rate Variability Using Time-Frequency Analysis, Kilbrom T. Hailu

Theses

ECG recordings, especially during an exercise stress test, are exposed to artifacts. The source of artifacts can be due to technical problems, biological events and errors in the automatic detection. As a result missed beats, extra beats and ectopic beats can occur. In this study analysis of missed beats is performed using time-frequency analysis. Some of the patient's data had missed beats.

Fourier spectral analysis was first applied to the missed beats during the resting state. The impact of missed beats using Fourier spectral analysis is significant, especially, when the missed beats are in a row. The Fourier spectral analysis …

Non-Invasive Monitoring Of Bone Health Using Ultrasound, Nashit Jahan Meem

Theses

Bone fractures are estimated to afflict everyone at least once in his/her lifetime. Monitoring this becomes crucial especially when it comes to athletes in order for them to safely resume their regular activities as soon as possible. Technologies currently employed are either very expensive or use harmful radiation.

Ultrasound can monitor bone fractures in a non-invasive manner, as discussed in United States Patent # 5143069. Three transducers are mounted over the test specimen. A pulse generator excites the transmitting receiver. The second receiver is mounted next to the transmitter and acts as a reference receiver that displays the response across …

Qt Variability Calculation Using A Template Matching Algorithm And Power Spectral Analysis, Theodore Sami Rizkalla

Theses

ECG interval measurement and variability analysis has proven to be a useful tool in investigating autonomic nervous system function. Traditionally, the R to R interval has been the thrust of research conducted in this field. QT variability is another topic on which little research has been done.

This thesis uses an algorithm proposed by Dr. Berger, published in 2003. The algorithm stretches the template in the time domain, and composes a sum-squared error function, which is minimized to find the scaling factor for that beat. These scaling factors are compiled into an array, and an interpolated signal is generated of …