Biomedical Engineering and Bioengineering Commons^™

An Investigation Of Markov Random Fields For Bayesian Reconstruction Of Single Photon Emission Computed Tomography, Lloyd Fredrick Arrowood

Doctoral Dissertations

This research investigates the use of Markov random fields for Bayesian reconstruction algorithms to be used with high-resolution and high-sensitivity SPECT systems for small animal imaging. It extends previous research on mechanical models for Bayesian image reconstruction by using a three-dimensional nonconforming finite element model and linear elasticity concepts to derive minimum potential energy functionals which regularize the reconstruction process. It combines dual collimator SPECT projection data by using high-resolution data to penalize lower-resolution data. It compares the new three-dimensional penalized reconstruction technique with existing penalized techniques through the use of modulation transfer and contrast discrimination functions.

Multiscale Modeling Of Toxoplasma Gondii, Adam Michael Sullivan

Doctoral Dissertations

Toxoplasma gondii is a potentially deadly parasite that uses a very unique way of manipulating the cell and immune systems. To investigate the mechanics of how the parasite spreads within hosts, several interwoven topics related to the study of within-host dynamics of Toxoplasma gondii are presented here. Understanding the complicated methods of how the parasite grows, dies, invades, replicates, and evades the host immune response is the critical aim of this independent research. Understanding the processes of acute and chronic infection are studied independently, followed by modeling the two processes in the same model. Finally, the dynamic models are simulated …

Automated Home Apnea System, Collin G. Howser, Trevor Grieco

Chancellor’s Honors Program Projects

No abstract provided.

Femtosecond Laser Patterned Templates And Imprinted Polymer Structures, Deepak Rajput

Doctoral Dissertations

Femtosecond laser machining is a direct-write lithography technique by which user-defined patterns are efficiently and rapidly generated at the surface or within the bulk of transparent materials. When femtosecond laser machining is performed with tightly focused amplified pulses in single-pulse mode, transparent substrates like fused silica can be surface patterned with high aspect ratio (>10:1) and deep (>10 μm) nanoholes. The main objective behind this dissertation is to develop single-pulse amplified femtosecond laser machining into a novel technique for the production of fused silica templates with user-defined patterns made of high aspect ratio nanoholes. The size of the …

Universal Personal Transfer, Arian Nasab

Chancellor’s Honors Program Projects

No abstract provided.

Dynamic Mutual Capacitive Sensor For Human Interactions., Jonathan William Huber

Doctoral Dissertations

This dissertation introduces the novel concept of removing the ground conductive plate by utilizing body capacitance as the ground in the capacitive sensor, whereby circuit pressure sensing can occur with only one plate and one dielectric. Additionally, body capacitance sensing was limited to a binary touch-no-touch output, whereas the method presented here can sense various applied pressures. The resulting circuit acts as an antenna that receives local capacitance signals from a human interaction.

The advantage of this design is that it allows for both proximity sensing and pressure sensing (once the body part is touching the dielectric material). This setup …

An Investigation Of Rare Earth Co-Doping In Fluorochlorozirconate Glass-Ceramic Imaging Plates To Improve The Storage Phosphor Properties For Computed Radiography, Sharon Gray

Masters Theses

Computed radiography is a standard medical imaging technology that uses photostimulable storage phosphor imaging plates to create an image. X-rays create electron hole pairs within the plate which recombine upon stimulation by a laser, producing light which is read out and stored as a digital image. Modern imaging plates contain an active layer of crystalline storage phosphors embedded in a polymer binder. The resolution of images from these plates is reduced due to light scattering at grain boundaries during readout. Fluorochlorozirconate (FCZ) glass-ceramic imaging plates containing BaCl₂:Eu²⁺ [barium chloride] [europium]nanocrystals in the orthorhombic phase have been developed …

Computer Modeling And Signal Analysis Of Cardiovascular Physiology, Henian Xia

Doctoral Dissertations

This dissertation aims to study cardiovascular physiology from the cellular level to the whole heart level to the body level using numerical approaches.

A mathematical model was developed to describe electromechanical interaction in the heart. The model integrates cardio-electrophysiology and cardiac mechanics through excitation-induced contraction and deformation-induced currents. A finite element based parallel simulation scheme was developed to investigate coupled electrical and mechanical functions. The developed model and numerical scheme were utilized to study cardiovascular dynamics at cellular, tissue and organ levels. The influence of ion channel blockade on cardiac alternans was investigated. It was found that the channel blocker …

Quaternionic Attitude Estimation With Inertial Measuring Unit For Robotic And Human Body Motion Tracking Using Sequential Monte Carlo Methods With Hyper-Dimensional Spherical Distributions, Gary To

Doctoral Dissertations

This dissertation examined the inertial tracking technology for robotics and human tracking applications. This is a multi-discipline research that builds on the embedded system engineering, Bayesian estimation theory, software engineering, directional statistics, and biomedical engineering.

A discussion of the orientation tracking representations and fundamentals of attitude estimation are presented briefly to outline the some of the issues in each approach. In addition, a discussion regarding to inertial tracking sensors gives an insight to the basic science and limitations in each of the sensing components.

An initial experiment was conducted with existing inertial tracker to study the feasibility of using this …

Melt Blown Poly(Lactic Acid) For Application As A Tissue Engineering Scaffold, William Horst Gazzola

Masters Theses

Poly(lactic acid) (PLA) was melt blown (MB) under varying processing conditions to create webs with micro and nano-architecture. Processing parameters varied were primary air flow rate and collector distance. In total, twenty-one webs were produced and the physical properties of the webs were investigated including, mean fiber diameter and fiber diameter distribution, mean pore diameter and pore size distribution, web thickness, degree of crystallinity, tensile modulus and degradation rate. Four webs, two with micro and two with nano-architecture, thought suitable for use as tissue engineering scaffolds were selected for seeding with A375 human malignant melanoma cells. Cell culture was conducted …

Modulation Of Bone And Nerve Cell Behavior Using Biodegradable Polymer Networks, Lei Cai

Doctoral Dissertations

This dissertation presents novel biodegradable and photo-crosslinkable building blocks to achieve polymer networks with controlled surface chemistry, stiffness, and topographical features for investigating cell-material interactions and targeting hard and soft tissue engineering applications. Chapter I reviews the recent progress in polymeric gel systems and how their physical properties can be tailored to regulate cell functions and satisfy the clinical needs. Chapter II presents a facile method to synthesize photo-crosslinkable poly(epsilon-caprolactone) acrylates (PCLAs) and reveal tunable cell responses to photo-crosslinked PCLAs. Chapter III investigates the mechanism of colorization in preparing crosslinkable polymers by reacting hydroxyl-containing polymers with unsaturated anhydrides or acyl …

Vision-Based Robot Control In The Context Of Human-Machine Interactions, Andrzej Nycz

Doctoral Dissertations

This research has explored motion control based on visual servoing – in the context of complex human-machine interactions and operations in realistic environments. Two classes of intelligent robotic systems were studied in this context: operator assistance with a high dexterity telerobotic manipulator performing remote tooling-centric tasks, and a bio-robot for X-ray imaging of lower extremity human skeletal joints during natural walking. The combination of human-machine interactions and practical application scenarios has led to the following fundamental contributions: 1) exploration and evaluation of a new concept of acquiring fluoroscope images of musculoskeletal features of interest during natural human motion, 2) creation …

Three-Dimensional Kinematic Analysis Using The Xbox Kinect, Robert Matthew Wham

Chancellor’s Honors Program Projects

No abstract provided.

A Novel Imaging System For Automatic Real-Time 3d Patient-Specific Knee Model Reconstruction Using Ultrasound Rf Data, Rimon Adel Messiha Tadross

Doctoral Dissertations

This dissertation introduces a novel imaging method and system for automatic real-time 3D patient-specific knee model reconstruction using ultrasound RF data. The developed method uses ultrasound to transcutaneously digitize a point cloud representing the bone’s surface. This point cloud is then used to reconstruct 3D bone model using deformable models method.

In this work, three systems were developed for 3D knee bone model reconstruction using ultrasound RF data. The first system uses tracked single-element ultrasound transducer, and was experimented on 12 knee phantoms. An average reconstruction accuracy of 0.98 mm was obtained. The second system was developed using an ultrasound …

Development And Experimental Analysis Of Wireless High Accuracy Ultra-Wideband Localization Systems For Indoor Medical Applications, Michael Joseph Kuhn

Doctoral Dissertations

This dissertation addresses several interesting and relevant problems in the field of wireless technologies applied to medical applications and specifically problems related to ultra-wideband high accuracy localization for use in the operating room. This research is cross disciplinary in nature and fundamentally builds upon microwave engineering, software engineering, systems engineering, and biomedical engineering. A good portion of this work has been published in peer reviewed microwave engineering and biomedical engineering conferences and journals. Wireless technologies in medicine are discussed with focus on ultra-wideband positioning in orthopedic surgical navigation. Characterization of the operating room as a medium for ultra-wideband signal transmission …

Characteristics And Functionalities Of Natural And Bioinspired Nanomaterials, Lijin Xia

Doctoral Dissertations

Green nanoscience is a rapidly emerging field that aims to achieve the maximum performance and benefits from nanotechnology, while minimizing the impact on the environment. In this study, several methods for the green nanomanufacturing of biomedically important nanomaterials, specifically through the use of natural plants, have been extensively investigated. It was found that natural nanomaterials are inherent within plants, and can be further manipulated for potential biomedical applications. In addition, the metabolites and reductive capacity of plant extracts can be used to synthesize metallic nanoparticles with advantages over semi-conductor based nanomaterials. Nanoparticles were found to exist in the extracts produced …

A Novel Free Form Femoral Cutting Guide, Wesley Andrew Underwood

Masters Theses

Knee arthoplasty is a common procedure that requires the removal of damaged bone and cartilage from the distal femur so that a reconstructive implant may be installed. Traditionally, a five planar resection has been accomplished with a universal cutting box and navigated with either metal jigs or optically tracked computer navigation systems. Free form, or curved, resections have been made possible with surgical robots which control the resection pathway and serve as the navigation system. The free form femoral cutting guide serves as a non powered framework to guide a standard surgical drill along an anatomically defined pathway, resulting in …

Comparative Study On Posture And Its Influences On Horizontal Ground Reaction Forces Generated By Muscles: Implications For Crouch Gait, Hoa Xuan Hoang

Masters Theses

Crouch gait decreases walking efficiency due to the increased knee and hip flexion during the stance phase of gait. Crouch gait is generally considered to be disadvantageous for patients with cerebral palsy; however, a crouched posture may afford biomechanical advantages that lead some patients to adopt a crouch gait.

To investigate one possible advantage of crouch gait, a musculoskeletal model created in OpenSim was placed in 15 different postures from upright to severe crouch during initial, middle, and final stance of the gait cycle. A series of optimizations were performed for each posture to maximize ground reaction forces for the …

Dynamics, Electromyography And Vibroarthrography As Non-Invasive Diagnostic Tools: Investigation Of The Patellofemoral Joint, Filip Leszko

Doctoral Dissertations

The knee joint plays an essential role in the human musculoskeletal system. It has evolved to withstand extreme loading conditions, while providing almost frictionless joint movement. However, its performance may be disrupted by disease, anatomical deformities, soft tissue imbalance or injury. Knee disorders are often puzzling, and accurate diagnosis may be challenging. Current evaluation approach is usually limited to a detailed interview with the patient, careful physical examination and radiographic imaging. The X-ray screening may reveal bone degeneration, but does not carry sufficient information of the soft tissue conditions. More advanced imaging tools such as MRI or CT are available, …

Applications Of Nanoparticle Image Velocimetry In Nanofluids, Sara Salim Haque

Masters Theses

Particle Image Velocimetry (PIV) is an optical technique used for the visualization of fluid flow. PIV can be combined with other techniques to enhance the analysis of fluid flow. A novel far-field plasmonic resonance enhanced nanoparticle-seeded Particle Image Velocimetry (nPIV) has been demonstrated to measure the velocity in a micro channel. Chemically synthesized silver nanoparticles have been used to seed the flow. By using Discrete Dipole Approximation (DDA), plasmonic resonance enhanced light scattering has been calculated for spherical silver nanoparticles with diameters ranging from 15 nm to 200 nm in two media: water and air. The diffraction-limited plasmonic resonance enhanced …

Seasonal Initial Concentrations And In-Field Decay Rates Of Escherichia Coli And Bovine Bacteroidetes In Beef Cattle Manure, Jiangwei Liu

Masters Theses

Eight naturally deposited beef cow manure patties were sampled during summer (July 19 to August 9, 2010), fall (October 26 to November 19, 2010), winter (January 14 to February 18, 2011), and spring (May 5-27, 2011) to determine whether hypothesized seasonal differences existed in the initial concentrations and decay rates of Escherichia coli (E. coli) and bovine Bacteroidetes (BoBac). E. coli concentrations were estimated as culturable colony forming units (CFU) and with a quantitative polymerase chain reaction (qPCR) assay targeting the 23S ribosomal gene. BoBac was quantified with a qPCR assay targeting a 16S ribosomal gene sequence associated …

Positron Emission Tomography (Pet) For Flow Measurement, Bi Yao Zhang

Masters Theses

Positron Emission Tomography (PET) is frequently used for medical imaging. Maturity and flexibility of PET as an imaging technique has expanded its utility beyond the medical domain. It can be used as a tool for fluid flow studies in opaque fluids and for flow within complex geometry where conventional optical flow measurement approaches fail. This study explores the capabilities of PET as flow measurement tool suited to validation of computational fluid dynamic (CFD) predictions.

The MicroPET P4 scanner was used to image the diffusion process in flow around a rod bundle geometry similar to that found in a nuclear reactor …

Modeling Of Human Hand Motion In A Maya Environment, Andrew M. Quinn, Aeshan Ali, Tessa Taylor, Quincy Beasley

Chancellor’s Honors Program Projects

No abstract provided.

Feasibility Of A Touch Sensitive Breast Phantom For Use In The Training Of Physicians In Clinical Breast Examination, Corinne Ashlie Davis, Katherine Lynn Mittura, Grace Elizabeth Copeland, Erica Martina Hawkins

Chancellor’s Honors Program Projects

No abstract provided.

Synthesis And Characterization Of Diamond-Like Carbon Thin Films For Biomedical Applications, Russell Lee Leonard

Masters Theses

Diamond-like carbon (DLC) thin films were produced by pulsed laser deposition (PLD) on silicon, fused silica, and silicon nitride substrates. The films produced were either undoped, made using a pure graphite target, or doped, using multi-component targets made from a combination of graphite and silicon, silicon nitride, titanium dioxide, or silicon monoxide. These films were evaluated for their potential use in biomedical applications, including coatings for artificial joints, heart stents, and bronchoscopes. The films were characterized by Raman spectroscopy, atomic force microscopy, ball-on-flat tribometry, contact angle measurements, and spectrophotometry. Film thickness was determined by optical profilometry. Film adhesion was checked …

Polymeric Microsensors For Intraoperative Contact Pressure Measurement, Emily R. Pritchard

Doctoral Dissertations

Biocompatible sensors have been demonstrated using traditional microfabrication techniques modified for polymer substrates and utilize only materials suitable for implantation or bodily contact. Sensor arrays for the measurement of the load condition of polyethylene spacers in the total knee arthroplasty (TKA) prosthesis have been developed. Arrays of capacitive sensors are used to determine the three-dimensional strain within the polyethylene prosthesis component. Data from these sensors can be used to give researchers a better understanding of component motion, loading, and wear phenomena for a large range of activities. This dissertation demonstrates both analytically and experimentally the fabrication of these sensor arrays …

Developing Chitosan-Based Biomaterials For Brain Repair And Neuroprosthetics, Zheng Cao

Masters Theses

Chitosan is widely investigated for biomedical applications due to its excellent properties, such as biocompatibility, biodegradability, bioadhesivity, antibacterial, etc. In the field of neural engineering, it has been extensively studied in forms of film and hydrogel, and has been used as scaffolds for nerve regeneration in the peripheral nervous system and spinal cord. One of the main issues in neural engineering is the incapability of neuron to attach on biomaterials. The present study, from a new aspect, aims to take advantage of the bio-adhesive property of chitosan to develop chitosan-based materials for neural engineering, specifically in the fields of brain …

Identification And Quantification Of Cotton Yield Monitor Errors, Jason Clay Head

Masters Theses

Cotton yield monitors are an important part of a precision agriculture program and are becoming widely used by cotton producers for making management decisions. Members of the cotton industry have shown interest in using cotton yield monitors for collecting data from production scale variety yield trials (experiments that test yield performance for numerous varieties). Weighing boll buggies are the current industry standard for measuring yield in variety trials. This process is time consuming and requires extra equipment and labor. The ability to use a yield monitor for measuring yield would streamline variety trial harvesting. Recommendations for the Ag Leader cotton …

Vibration Analysis Of Heavy-Duty Diesel Vehicles, Christopher Jack Campbell

Masters Theses

Truck drivers are more susceptible than other workers to lower back pain and spinal disorders caused by whole body vibrations, which are among the most common long term health effects for drivers. The dynamic behavior of trucks can be modeled and simulated to improve the design of the trucks, which can reduce the exposure of drivers to whole body vibrations.

The main purposes of this study are to analyze vibrations for different manufacturers and road types, and to create a computer-based model using Adams to predict vibration anywhere on the model using acceleration data collected previously from on-road tests of …

Insight Into The Gating Mechanism Of Mechanosensitive Ion Channels Using A Simple Structure: A Step In The Analysis Of Commotio Cordis, Sumeet Kaul

Masters Theses

Mechanosensation in cells is a well known phenomenon that is associated with cellular responses to force. Our knowledge of the trigger mechanism of this phenomenon is, however, limited. Earlier studies in this field have used atomic simulations, which although being accurate, are limited in their feasibility in multi-length scenarios like a mechanosensitive channel that undergoes micro-level changes in the composition of the protein to cause a macro-level change in the state of a biological structure such as the muscle. Finite Element Analysis has been used in various engineering fields to study the mechanical response of complex structures. The current study …