Biomedical Engineering and Bioengineering Commons^™

Bowen Ratio Energy Balance Measurement Of Carbon Dioxide (Co2) Fluxes Of No-Till And Conventional Tillage Agriculture In Lesotho, Debra Blumberg O'Dell, Thomas J. Sauer, Bruce B. Hicks, Dayton M. Lambert, David R. Smith, Wendy Bruns, August Basson, Makoala V. Marake, Forbes Walker, Michael D. Wilcox Jr., Neal Samuel Eash

Biosystems Engineering and Soil Science Publications and Other Works

Global food demand requires that soils be used intensively for agriculture, but how these soils are managed greatly impacts soil fluxes of carbon dioxide (CO₂). Soil management practices can cause carbon to be either sequestered or emitted, with corresponding uncertain influence on atmospheric CO₂ concentrations. The situation is further complicated by the lack of CO₂ flux measurements for African subsistence farms. For widespread application in remote areas, a simple experimental methodology is desired. As a first step, the present study investigated the use of Bowen Ratio Energy Balance (BREB) instrumentation to measure the energy balance and …

The Advancement Of Bacterial Cellulose As A Bone And Vascular Scaffolds, Ryan Lee Hammonds

Doctoral Dissertations

Bacterial cellulose (BC) is a natural hydrogel made of nanofibers. This material has been used in commercial products, including wound dressings. BC can be modified and optimized for improved performance in multiple applications. This work will focus on producing and characterizing resorbable cellulose, a composite for bone applications, and a composite for a synthetic venous valve leaflet.

BC can be produced and modified to perform as a degradable tissue scaffold. This is achieved by an oxidation procedure after the initial production and purification of native BC. A material characterization of oxidized BC was performed to identify the changes in properties …

Analysis, Segmentation And Prediction Of Knee Cartilage Using Statistical Shape Models, Joseph Michael Johnson

Doctoral Dissertations

Osteoarthritis (OA) of the knee is one of the leading causes of chronic disability (along with the hip). Due to rising healthcare costs associated with OA, it is important to fully understand the disease and how it progresses in the knee. One symptom of knee OA is the degeneration of cartilage in the articulating knee. The cartilage pad plays a major role in painting the biomechanical picture of the knee. This work attempts to quantify the cartilage thickness of healthy male and female knees using statistical shape models (SSMs) for a deep knee bend activity. Additionally, novel cartilage segmentation from …

Reconstruction Of Patient-Specific Bone Models From X-Ray Radiography, Hatem Amin Abdel Fattah El Dakhakhni

Doctoral Dissertations

The availability of a patient‐specific bone model has become an increasingly invaluable addition to orthopedic case evaluation and planning [1]. Utilized within a wide range of specialized visualization and analysis tools, such models provide unprecedented wealth of bone shape information previously unattainable using traditional radiographic imaging [2]. In this work, a novel bone reconstruction method from two or more x‐ray images is described. This method is superior to previous attempts in terms of accuracy and repeatability. The new technique accurately models the radiological scene in a way that eliminates the need for expensive multi‐planar radiographic imaging systems. It is also …

Automated Fragmentary Bone Matching, Ali Saad Mustafa

Masters Theses

Identification, reconstruction and matching of fragmentary bones are basic tasks required to accomplish quantification and analysis of fragmentary human remains derived from forensic contexts. Appropriate techniques for three-dimensional surface matching have received great attention in computer vision literature, and various methods have been proposed for matching fragmentary meshes; however, many of these methods lack automation, speed and/or suffer from high sensitivity to noise. In addition, reconstruction of fragementary bones along with identification in the presence of reference model to compare with in an automatic scheme have not been addressed. In order to address these issues, we used a multi-stage technique …

An Implantable Low Pressure Biosensor Transponder, Chad Eric Seaver

Masters Theses

The human body’s intracranial pressure (ICP) is a critical element in sustaining healthy blood flow to the brain while allowing adequate volume for brain tissue within the relatively rigid structure of the cranium. Disruptions in the body’s maintenance of intracranial pressure are often caused by hemorrhage, tumors, edema, or excess cerebral spinal fluid resulting in treatments that are estimated to globally cost up to approximately five billion dollars annually. A critical element in the contemporary management of acute head injury, intracranial hemorrhage, stroke, or other conditions resulting in intracranial hypertension, is the real-time monitoring of ICP. Currently such monitoring can …

Discrete Geometric Based Stress Analysis Of The Lumbar Soft Tissues From In Vivo Kinematics, Joseph W. Mitchell

Doctoral Dissertations

Back pain in the region of the lumbar spine has become an increasingly significant problem among individuals in the United States and is a leading cause of disability and missed work days. At present, efforts focused on treating both the symptoms and causes of low back pain have proven to be difficult, and researchers and clinicians still do not fully understand the most effective means for treating the symptoms. Utilizing a biomechanics approach, it is assumed that lower back pain is, at least in part, associated with an increased localized stress.

Current models used to determine stresses are typically based …

Human Motion Analysis With Wearable Inertial Sensors, Xi Chen

Doctoral Dissertations

High-resolution, quantitative data obtained by a human motion capture system can be used to better understand the cause of many diseases for effective treatments. Talking about the daily care of the aging population, two issues are critical. One is to continuously track motions and position of aging people when they are at home, inside a building or in the unknown environment; the other is to monitor their health status in real time when they are in the free-living environment. Continuous monitoring of human movement in their natural living environment potentially provide more valuable feedback than these in laboratory settings. However, …

Green Manufacturing Of Nanoparticles For Biomedical Applications, Sijia Yi

Doctoral Dissertations

The vast majority of nanomaterials are chemically synthesized, a costly process, that is environmentally risky, and the produced nanoparticles are potentially toxic to patients. Nature-based nanomaterials, however, are proving to be much more biocompatible with lower environmental toxicity. Even though a variety of natural nanomaterials have been designed, fabrication technologies for the desired natural nanoparticles with reproducible quality, high productivity and low cost remain a challenge. My objective has been to establish strategies for the isolation, purification and characterization of nanoparticles using a production system based on green tea and fungus (Arthrobotrys oligospora) and also to develop new …

Development Of A Computational Methodology For Evaluating In Vivo Vertebral Mechanics In Subjects Having Various Conditions Of The Lumbar Spine, Christopher Brian Carr

Doctoral Dissertations

Treating and evaluating the causes of low back pain (LBP) is difficult and not fully understood. However, assessing the in vivo motions and loading characteristics in the lumbar spine may provide important data for progressing the diagnosis and treatment of pathologies linked with LBP.

This dissertation describes the development of a comprehensive approach for collecting both the kinematics and kinetics of the lumbar vertebrae under in vivo conditions. Forty-four subjects representing healthy, symptomatic, pathological, and surgically implanted (pre- and post-operative) conditions of the lumbar spine were evaluated using dynamic fluoroscopy and 3D-to-2D image registration to assess the motions of the …

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 …

Elucidating Role Of Heart Valve Cells In The Aortic Valve Calcification, Mary Katherine Bailey, Adithi Amarnath

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

No abstract provided.

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 …

A Fully Coupled Model For Electromechanics Of The Heart, Henian Xia, Kwai Wong, Xiaopeng Zhao

Faculty Publications and Other Works -- Mechanical, Aerospace and Biomedical Engineering

We present a fully coupled electromechanical model of the heart. The model integrates cardiac electrophysiology and cardiac mechanics through excitation-induced contraction and deformation-induced current. Numerical schemes based on finite element were implemented in a supercomputer. Numerical examples were presented using a thin cardiac tissue and a dog ventricle with realistic geometry. Performance of the parallel simulation scheme was studied. The model provides a useful tool to understand cardiovascular dynamics.

http://dx.doi.org/10.1155/2012/927279

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 …