Engineering 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 …

Application Of Advanced Computational Modelling In The Numerical Prediction Of The Haemodynamic Impact Of Coronary Stent Implantation, Jonathan Murphy, Fergal Boyle

Conference Papers

Coronary stent implantation can improve blood flow in an artery narrowed by the build up of arterial plaque. However, the haemodynamic effect of stent placement is unclear and may influence arterial restenosis (re-blockage). In this investigation the stent induced, non-Newtonian blood flow disturbances have been captured in a three dimensional computational domain. The results clearly show areas of low wall shear stress proximal and distal to the stent wires, a characteristic which is known to encourage restenosis. Furthermore, this computational method of observing the complex haemodynamics of the stent environment can be used in conjunction with medical trial data to …

Miniature Optical Coherence Tomography Probe, Asif Rizwan

Bioengineering Theses

A piezo based optical scanner for high speed optical coherence tomography (OCT) has been developed. Design of the miniature probe has been optimized to take advantages of the high speed depth scanning that can be achieved with spectral domain OCT (SD-OCT) systems. Three prototype scanning probes were constructed and tested for OCT imaging. Movies and images of tissues are presented which were taken at frame rates ranging from 50~100fps. Data were acquired at 18000 A-lines per second at an effective integration time of 55us.

A Comprehensive Study Of The Effects Of Eeg Electrode Arrays On Mri Signal-To-Noise At 3t, Aman Ish Goyal

Bioengineering Theses

Simultaneous EEG-fMRI offers much potential for gaining complementary, noninvasive information about brain function. While much effort has been devoted to the compelling problem of removing ballistocardiogram and gradient artifacts from the EEG waveforms, less attention has been paid to the impact that increasing density of electrode arrays has on the MR images. Initial work reporting the effects of EEG caps and electrodes on the MR image has been site specific, using customized EEG equipment that those research groups built in-house. Therefore these results are hard to generalize to other laboratory environments. A monotonic decrease in SNR of the images has …

Fiber Based Non-Linear Excitation Fluorescence Microscopy, Priyanka Amrita Jillella

Bioengineering Theses

Non-linear excitation fluorescence microscopy is a high resolution, non-invasive biological imaging technique capable of imaging both in vitro and in vivo at the depths of several hundred microns. The goal of the thesis work is to contribute towards a fiber based non-linear excitation fluorescence microscopy system that we plan to build for our lab, which would later on be integrated with the OCT imaging setup and the DIC microscope. This thesis work involves filling in the key components in the microscopy system. These key components are; femtosecond pulse diagnosis, study of dispersion in optical media, dispersion free femtosecond pulse delivery …

Spectroscopic Characterization Of Biliary Tract Tissues In-Vivo To Assist Laparoscopic Cholecystectomy, Sarita Kommera

Bioengineering Theses

Laparoscopic Cholecystectomy is a surgical method for removal of gallbladder when it is diseased with gall stones. Almost 750,000 people are affected with this disease annually in USA. Gall bladder is removed by placing an incision on the cystic duct. This duct is totally embedded in fat (which is a few mm thick) in most of the cases and it becomes a huge problem decreasing the visual capability of the surgeon to distinctly locate the duct. Near Infrared Spectroscopy (NIRS) can solve the fuzziness as it penetrates in a few mm thick tissues. NIRS is one of the simplest techniques …

Novel Intraocular Drug Delivery System For The Prevention Of Posterior Capsule Opacification, Brett Thomes

Bioengineering Dissertations

Posterior capsule opacification (PCO) is a major complication associated with the implantation of intraocular lens (IOLs). Evidence suggests that PCO formation is caused by abnormal lens epithelial cell (LEC) migration/proliferation. We hypothesize that pharmacologic agents must target inflammatory cells in addition to LECs to inhibit PCO formation. To successfully target both inflammatory cells and LECs, a novel intraocular drug delivery system (DDS) was developed for implantation in the lens capsular bag. Such a system permits direct delivery of anti-inflammatory and anti-proliferative drugs in the lens capsule for extended periods of time resulting in reduced PCO formation. A lubricious polyurethane coating …

Optical Coherence Tomography Of Oral Mucosa, Nidhi Bharatbhai Mehta

Bioengineering Theses

Oral cancer causes 120000* deaths annually around the world and 280000* new cases are diagnosed every year. Technology has developed and the death rate of oral cancer has improved over the last few decades; hence to improve the survival rate, development of a technique able to diagnose carcinomas in its early stages is very important. OCT is a non invasive imaging technique capable to provide high resolution microstructure images of tissue. A development of in vivo OCT; capable to image tissue with micrometer resolution and able to identify pre cancerous morphological changes non invasively could improve survival rate in cancer …

Distensibility Differs Between Sall Arteries And Veins In The Newborn Piglet Lung, John B. Gordon, Steven Thomas Haworth, Robert C. Molthen, Gary S. Krenz, Anne V. Clough

Biomedical Engineering Faculty Research and Publications

BACKGROUND: We previously used micro-CT techniques to measure pulmonary artery distensibility in 3 week old piglets. Pressure/diameter relationships were measured for each artery and the slope (a) was then plotted against its diameter intercept at 0 pressure (Do). The resultant diameter independent distensibility parameter, a, was estimated by linear regression to be 1.6% per mmHg for arteries between 0.2 and 3.0 mm Do.

OBJECTIVE: This study sought to determine whether; 1) distensibility of smaller arteries was similar to that of arteries with Do> 0.2 mm; and 2) whether small vein and artery distensibility was similar.

DESIGN/METHODS: Lower lobes were isolated …

Two In Vivo Surgical Approaches For Lumbar Corpectomy Using Allograft And A Metallic Implant: A Controlled Clinical And Biomechanical Study, Philbert Huang, Munish C. Gupta, Nesrin Sarigul-Klijn, Scott Hazelwood

Biomedical Engineering

Background context: Both bone graft and metallic implants have been used in combination with the necessary anterior rod or plate instrumentation to fill the voids left by vertebral body removal, with the ultimate goal of restoring stability. One type of device that has recently been introduced is an expandable titanium telescoping cage that is designed to be used as a strut implant to fill corpectomy defects. The use of these devices has met varying success. Acceptance by surgeons and spine biomechanicians has been limited by clinical failure with subsequent loss of reduction and increase in kyphosis. In order to further …

Department Of Biological Systems Engineering Newsletter, Issue 2, November 2006

BSE Department Magazine

Contents:
Visiting Scholar
Big changes in the BSE Computer Lab
From the Department Head
National Science Foundation Initiative Moving to Transform Water and Environment Research ByWayneWoldt
ASABE Awards
Nebraska Tractor Test Lab Welcomes New Director
Alumni News
August Graduation
College of Agricultural Sciences and Natural Resources Alumni Association (CASNRAA)
Hydrologic Studies in Prairie and Agricultural Watersheds Gleanings from a Faculty Development Leave by Dean E. Eisenhauer
Irrigation and Energy Conservation Field Day By Suat Irmak
P3–Ten Years
Hall of Fame
Vegetative Treatment Systems Help Small Livestock Producers Control Animal Waste by Kalee Olson
Ice Cream Social & Scholarship Recognition
Student …

Concept Frequency Distribution In Biomedical Text Summarization, Lawrence H. Reeve, Hyoil Han, Saya V. Nagori, Jonathan C. Yang, Tamara A. Schwimmer, Ari D. Brooks

Computer Sciences and Electrical Engineering Faculty Research

Text summarization is a data reduction process. The use of text summarization enables users to reduce the amount of text that must be read while still assimilating the core information. The data reduction offered by text summarization is particularly useful in the biomedical domain, where physicians must continuously find clinical trial study information to incorporate into their patient treatment efforts. Such efforts are often hampered by the high-volume of publications. Our contribution is two-fold: 1) to propose the frequency of domain concepts as a method to identify important sentences within a full-text; and 2) propose a novel frequency distribution model …

Oxidized Derivatives Of Ω-3 Fatty Acids: Identification Of Ipf 3Α-Vi In Human Urine, John A. Lawson, Seongjin Kim, William S. Powell, Garret Gerald A. Fitzgerald, Joshua Rokach

Chemistry and Chemical Engineering Faculty Publications

Isoprostanes (iPs) are prostaglandin-like molecules derived from autoxidation of polyunsaturated fatty acids (PUFAs). Urinary iP levels have been used as indices of in vivo lipid peroxidation. Thus far, it has only been possible to measure iPs derived from arachidonic acid in urine, because levels of iPs/neuroprostanes (nPs) derived from ω3-PUFAs have been found to be below detection limits of available assays. Because of the interest in ω3-PUFA dietary supplementation, we developed specific methods to measure nPF4α-VI and iPF3α-VI [derived from 4,7,10,13,16,19-docosahexaenoic acid (DHA) and 5,8,11,14,17-eicosapentaenoic acid (EPA)] using a combination of chemical synthesis, gas chromatography/mass spectrometry (GC/MS), andliquid chromatography tandem …

Procedure To Quantify Biofilm Activity In Carriers Used In Wastewater Treatment Systems, James Bolton, Archana Tummala, Chirag Kapadia, Manoj Dandamudi, Joanne M. Belovich

Chemical & Biomedical Engineering Faculty Publications

A procedure is presented for evaluating and comparing the biological activity of biofilms attached to various biofilm carriers by measurement of the glucose consumption rate. This technique allows for the economical design and selection of small particulate biofilm carriers that will maximize substrate removal when used in industrial-scale fluidized bioreactors. Methods for ensuring reproducible results are described. To support the glucose consumption rate findings, biofilm dry weights were obtained at the conclusion of activity rate experiments, and scanning electron micrographs were taken to evaluate the presence of biofilm and to view surface characteristics. Fourteen different biofilm carriers were evaluated ranging …

Incorporation Of Polyethylene Glycol Into Self-Assembled Monolayers Enhances Substrate-Mediated Gene Delivery By Nonspecifically- Bound Complexes, Angela K. Pannier, Lonnie D Shea

Department of Biological Systems Engineering: Conference Presentations and White Papers

Developing systems capable of controlled and efficient gene transfer is a fundamental goal of biotechnology, with applications including functional genomics, gene therapy, and tissue engineering. Substrate-mediated delivery, also termed solid phase delivery, describes the immobilization of DNA, complexed with nonviral vectors, to a biomaterial or substrate through specific or nonspecific interactions. Cells cultured on the substrate are exposed to elevated DNA concentrations within the local microenvironment, which enhances transfection. We investigated transfection resulting from DNA complexes immobilized to a substrate through specific interactions introduced through complementary functional groups on the vector and surface or through nonspecific interactions. Self-assembled monolayers (SAMs) …

Investigating Stiff-Knee Gait With Subject-Specific Simulations, Jeffrey A. Reinbolt, M. D. Fox, S. L. Delp

Jeffrey A. Reinbolt

No abstract provided.

A Novel Open Field Activity Detector To Determine Spatial And Temporal Movement Of Laboratory Animals After Injury And Disease, Andrew O. Koob, John Cirillo, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Among the wide range of tests for laboratory animal behavior after neurological injury or disease, each has its benefits and drawbacks. The varied behavior that an animal exhibits makes it difficult to decide which test to use. However, a fundamental instinct for the laboratory animal is to explore when placed in a new environment. A way to test exploratory behavior is in the open field. Here, we introduce a simple activity box without the use of video equipment to determine the exploratory movement of a rat after traumatic brain injury. The activity box is an open field, and the rat …

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 …

The Effect Of Auditory And Visual Distracters On The Useful Field Of View: Implications For The Driving Task, Joanne Wood, Alex Chaparro, Louise Hickson, Nick Thyer, Philippa Carter, Julie Hancock, Adrene Hoe, Ivy Le, Louisa Sahetapy, Floravel Ybarzabal

Publications

PURPOSE. The driving environment is becoming increasingly complex, including both visual and auditory distractions within the in-vehicle and external driving environments. This study was designed to investigate the effect of visual and auditory distractions on a performance measure that has been shown to be related to driving safety, the useful field of view.

METHODS. A laboratory study recorded the useful field of view in 28 young visually normal adults (mean 22.6 +- 2.2 years). The useful field of view was measured in the presence and absence of visual distracters (of the same angular subtense as the target) and with three …

Analysis Of Gait Characteristics In Mentally Handicapped Individuals, Prakriti Parijat, Jian Liu, Thurmon E. Lockhart, Courtney Haynes

Computer Sciences and Electrical Engineering Faculty Research

Physical and motor dysfunctions in mentally handicapped individuals predispose them to a higher risk of slip and fall accidents. It is estimated that over 60 million people are currently suffering with some level of developmentally related cognitive impairment (American Disability Act ADA, 2000). Mental retardation occurs in 2.5-3% of the general population. About 6-7.5 million mentally retarded individuals live in the United States alone (ADA, 2000). Slip induced fall accidents are a primary source of injury in people with mental retardation (MR). Often, the incidence of falls among this population is compounded by other disabilities such as autism, seizure, and …

Simulation-Based Treatment Planning For Knee Osteoarthritis, B. J. Fregly, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.

The Effect Of Plate Rotation On The Stiffness Of Femoral Liss: A Mechanical Study, Afshin Khalafi, Shane Curtiss, Scott Hazelwood, Philip Wolinsky

Biomedical Engineering

Objective: Malposition of the femoral Less Invasive Stabilization System (LISS) plate may alter its biomechanical behavior. This study compares the mechanical stability of ‘‘correctly’’ affixed LISS plates matching the slope of the lateral femoral condyle to ‘‘incorrectly’’ placed LISS plates fixed in external rotation relative to the distal femur.

Methods: A fracture gap model was created to simulate a comminuted supracondylar femur fracture (AO/OTA33-A3). Fixation was achieved using two different plate positions: the LISS plate was either placed ‘‘correctly’’ by internally rotating the plate to match the slope of the lateral femoral condyle, or ‘‘incorrectly’’ by externally rotating the plate …

Influence Of Two Changes In The Composition Of An Acrylic Bone Cement On Some Of Its Properties: The Case Of Surgical Simplex® P, S. Madigan, Mark R. Towler, G. Lewis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Influence of two changes in the composition of a self-curing acrylic bone cement on some of its properties are discussed. Acrylic bone cements are widely used in orthopedic surgery for the fixation of joint prosthesis and in vertebroplasty and kyphoplasty for the stabilization and augmentation of fractured vertebrae. The cement's curing process is the result of a free-radical polymerization of a mixture of poly (methyl 1 methacrylate) [PMMA] containing powder and a liquid monomer that has methyl methacrylate (MMA) in it. It is initiated by the decomposition of benzoyl peroxide (BPO) in the powder, activated by a tertiary amine in …

The Influence Of Ultrasonic Setting On Fluoride Release From Glass Polyalkenoate Cements, N. Rushe, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effects of ultrasonic setting on fluoride release from glass polyalkenoate cements (GPC) were investigated. Cements based on two different aluminosilicate glasses that contained silica, alumina, phosphate, and strontia were used for the experiment. A series of GPCs were examined to show that increased release F^- ion occurs, regardless of GPC composition. The results show that there is a greater release of fluoride from the ultrasonically set samples than those set chemically, regardless of the chemical composition. The snap set caused by the ultrasound is likely to be due to a combination of cavitation, improved mixing of the constituents, …