Engineering Commons^™

Application Of Pca To Cardiac Optical Mapping, Louis Woodhams

McKelvey School of Engineering Theses & Dissertations

Structural remodeling of the heart due to pathologies such as hypertension and myocardial infarction leads to the appearance of myofibroblasts, a phenotype largely absent in physiologic myocardium. While myofibroblasts are responsible for wound healing and structural repair of damaged myocardium, they are thought to have deleterious effects on electrical and mechanical properties of the heart. Understanding these effects is critical to developing effective treatments, and has motivated the development of a series of in vitro engineered heart tissues and cardiomyocyte-myofibroblast co-cultures whose mechanical and electrophysiological function can be deduced from video analysis. Electrophysiological properties are evident from changes in intensity …

Modeling Of A Head - Neck Assembly Drop Tower Impact Test Using Abaqus, Hussein Sharqi Owaid

Electronic Theses and Dissertations

There are numerous potential causes of traumatic brain injury (TBI) and concussions, including traffic accidents, contact during sports and falls. Protection from these injuries is paramount because of the problems that result from TBI, such as loss of thinking and memory capability. Head impact from falls, especially in elderly, can also result in severe to fatal injury and some effects of brain injury are often not visible. For these reasons and more a need exists for protective head gear that can keep persons safe during at risk physical activity and that can protect fall prone persons from accidental injuries. Part …

Dynamic In Vivo Skeletal Feature Tracking Via Fluoroscopy Using A Human Gait Model, William Patrick Anderson

Doctoral Dissertations

The Tracking Fluoroscope System II, a mobile robotic fluoroscopy platform, developed and built at the University of Tennessee, Knoxville, presently employs a pattern matching algorithm in order to identify and track a marker placed upon a subject’s knee joint of interest. The purpose of this research is to generate a new tracking algorithm based around the human gait cycle for prediction and improving the overall accuracy of joint tracking.

This research centers around processing the acquired x-ray images of the desired knee joint obtained during standard clinical operation in order to identify and track directly through the acquired image. Due …

Material Properties Design Using Simulations And Experiments For Powder Injection Molding Of Lead Zirconate Titanate (Pzt)., Bhushan Pramod Bandiwadekar

Electronic Theses and Dissertations

Powder injection molding (PIM) process simulations can be performed to minimize the number of injection molding experiments by estimating material properties necessary for PIM simulations. In current work, lead zirconate titanate (PZT) powder-polymer binder feedstock was compounded for 45 vol. % and 52 vol. % solids loading. PIM experiments on designed micro-pillar array geometry were performed using 52 vol. % PZT. Using PIM experiments results as basis, PIM simulations were performed on designed micro-pillar array geometries to understand the effectiveness of PIM simulations with the use of estimated feedstock properties in predicting molding behavior that have micro-features. Additionally, PIM simulations …

Usa Boccia Ball Ramp For Athletes With Quadriplegia, Alissa A. Koukourikos, Matthew Lee, Nathan Bernards

Mechanical Engineering

In this report, the design process in creating an assistive device for Boccia Classification 3 (BC3) players is outlined. The initial research steps, including research into the rules of the game, capabilities of the players, and existing products is documented to show where ideas for the product stemmed from. This transitions into requirements that the sponsor requested, and preliminary designs and ideas for the product. Finally, this report explains the details of the final design, which has been analyzed for safety, ease of use, and ability to function under different conditions. The processes of manufacturing and testing will also be …

Nonlinear Model-Based Control For Neuromuscular Electrical Stimulation, Ruzhou Yang

LSU Doctoral Dissertations

Neuromuscular electrical stimulation (NMES) is a technology where skeletal muscles are externally stimulated by electrodes to help restore functionality to human limbs with motor neuron disorder. This dissertation is concerned with the model-based feedback control of the NMES quadriceps muscle group-knee joint dynamics. A class of nonlinear controllers is presented based on various levels of model structures and uncertainties. The two main control techniques used throughout this work are backstepping control and Lyapunov stability theory.

In the first control strategy, we design a model-based nonlinear control law for the system with the exactly known passive mechanical that ensures asymptotical tracking. …

Multiple Consecutive Recapture Of Rigid Nanoparticles Using A Solid-State Nanopore Sensor, Jungsoo Lee

Mechanical Engineering Research Theses and Dissertations

Solid‐state nanopore sensors have been used to measure the size of a nanoparticle by applying a resistive pulse sensing technique. Previously, the size distribution of the population pool could be investigated utilizing data from a single translocation, however, the accuracy of the distribution is limited due to the lack of repeated data. In this study, we characterized polystyrene nanobeads utilizing single particle recapture techniques, which provide a better statistical estimate of the size distribution than that of single sampling techniques. The pulses and translocation times of two different sized nanobeads (80 nm and 125 nm in diameter) were acquired repeatedly …

Influence Of Scapular Notching On Contact Mechanics And Simulator Wear Of Reverse Total Shoulder Arthroplasty Implants, Michael William Griffiths

Electronic Thesis and Dissertation Repository

Scapular notching is a common complication of reverse total shoulder arthroplasty (RTSA) wherein the predominant focus of current literature has been on changes in osseous anatomy. However, the implications on RTSA performance from the damaged humeral cup is largely unknown. Therefore the present work describes the effects of the initiation and propagation of the humeral cup defect resulting from scapular notching through the use of finite element modeling and wear simulation, in order to assess changes in RTSA contact mechanics and tribological properties. A significant decrease in articular contact area and increase in maximum contact stress values was found for …

Hip Joint Function In People With Femoroacetabular Impingement Syndrome, Philip Malloy

Dissertations (1934 -)

Femoroacetabular impingement syndrome (FAIS) is a clinical hip disorder that represents symptomatic contact between the proximal femur and rim of the acetabulum during normal hip range of motion. FAIS has been described as a precursor to hip joint osteoarthritis (OA), and results in physical impairments and functional limitations in young individuals and active adults. Despite tremendous growth in arthroscopic hip surgery for FAIS, little is known about how this disorder affects dynamic hip joint function. The purpose of this dissertation was to investigate hip joint function, during clinical and functional activities, both before and after arthroscopic hip surgery for FAIS. …

Design Of A Passive Ankle Prosthesis With Energy Return That Increases With Increasing Walking Velocity, Alexander J. Folz

Master's Theses (2009 -)

Patients who undergo a transtibial (below the knee) amputation are often met with a difficult decision: selection of a prosthesis. Limitations of currently available prostheses motivate work on a new solution, the EaSY Walk, a passive device that mimics two key aspects of the natural ankle: non-linear rotational stiffness through implementation of a stiffening flexure mechanism and rotational work output that varies as a function of walking velocity to propel the user forward. To achieve the latter, a strategy to convert the maximum available translational energy acquired from deflection along the leg into rotational energy about the ankle joint through …

Experimental Measurements Of Far Field Cough Airflows Produced By Healthy And Influenza- Infected Human Subjects, Ahmed Faraj Alarbi Mohamed

Electronic Thesis and Dissertation Repository

The present work details an experimental study of the cough airflow fields produced by subjects infected with influenza and when they are convalescent, together with data from healthy cohorts. The PIV and HWA measurements were taken far downstream at 1 m from the source within a cough chamber, along with droplet sampling at two different locations and nasal swabs from the sick subjects. The measured data over different seasons were used to evaluate and compare the results from sick, convalescent and healthy subjects. Although a total of 8 sick participants from winter 2014 and 2017 yielded positive nasal swab analysis, …

Application Of Pca To Cardiac Optical Mapping, Louis Woodhams

Louis Woodhams

Cancer Diagnosis By Bioimpedance Spectroscopy And Computer-Assisted Pattern Recognition, Shahriar Shams

Mechanical Engineering Research Theses and Dissertations

The field of cancer diagnostics has always been one of the most complex and challenging areas in biomedical research, and there has been an increasing demand for more advanced clinical diagnostic equipment over the past four decades. In this thesis, a custom-made coaxial bioimpedance sensor was used, in combination with computer-aided pattern recognition tools, to identify cancer in tissue samples obtained from the formalin-fixed kidney of a 60 year-old male patient. Impedance data was collected using the coaxial sensor at 401 logarithmically-spaced frequency points ranging from 10 kHz to 100 MHz. Principle Component Analysis and Naive Bayes Classification techniques were …

Comparative Analysis Of Impact Attenuation Properties From Soccer Headgear, Kevin G. Mciver, Goutham N. Sankaran, Justin J. Markel, Tom M. Talavage, Larry J. Leverenz, Eric A. Nauman

The Summer Undergraduate Research Fellowship (SURF) Symposium

Athletes suffering from long-term neurocognitive deficiency due to subconcussive impacts is a major concern for football and soccer players today. Football players wear helmets that can help reduce injury risks like skull fractures, and these helmets must meet standard criteria that determinines how well a functional helmet should reduce accelerations of the player’s head. Currently no standard exists for testing soccer headgear despite studies demonstrating soccer players experience similar magnitudes of impacts. In this study, a modal impact hammer was used in conjunction with a Hybrid III 50th percentile test dummy head to simulate impacts experienced by soccer players to …

Bacterial Motility And Its Role In Biofilm Formation, Clayton J. Culp, Arezoo M. Ardekani, Adib Ahmadzadegan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Bacterial biofilms are known to cause millions of dollars in damage in the medical industry per year via infection of central venous catheters, urinary catheters, and mechanical heart valves. Unfortunately, there are some characteristics of biofilm formation that are yet to be fully understood. Recently much work has been done to investigate the motility characteristics of bacteria with hopes of better understanding the phenomena of biofilm formation. Still, one of the least understood stages is bacterial attachment or adhesion, a process designed to anchor bacteria in an advantageous environment. Providing a better understanding of bacterial motility near solid interfaces will …

Intrinsic Regulators Of Actomyosin Contractility Engendering Pulsatile Behaviors, Qilin Yu, Jing Li, Taeyoon Kim

The Summer Undergraduate Research Fellowship (SURF) Symposium

Actomyosin contractility regulates various biological processes including cell migration, muscle contraction, and tissue morphogenesis. Cell cortex underlying a membrane, which is a representative actomyosin network in eukaryote cells, exhibits dynamic contractile behaviors. Interestingly, the cell cortex shows reversible aggregation of actin and myosin called pulsatile contraction in diverse cellular phenomena, such as embryogenesis and tissue morphogenesis. While contractile behaviors have been studied in several in vitro experiments and computational studies, none of them demonstrated the pulsatile contraction of actomyosin networks observed in vivo. Here, we used an agent-based computational model based on Brownian dynamics to identify factors facilitating the pulsatile …

A Parametric Study Of The Mechanics Of Different Skin Flap Techniques, Steven J. Meza, Adrián Tepole Buganza

The Summer Undergraduate Research Fellowship (SURF) Symposium

In modern day plastic and reconstructive surgeries numerous skin flap designs have been developed and are used to close open wounds. Skin flaps are developed with the intention of imposing minimal tension in skin closure. Excessive tension can lead to poor blood flow that result in post-surgery complications such as necrosis. Currently there is no standard in choosing a skin flap design and a surgeon's choice is based personal experience. A comparison of the mechanical loading in these various designs has not yet been done. We have developed a parametric study, using finite element analysis, of two advancement skin flaps …

A Functional Subnetwork Approach To Designing Synthetic Nervous Systems That Control Legged Robot Locomotion, Nicholas Szczecinski, Alexander J. Hunt, Roger Quinn

Mechanical and Materials Engineering Faculty Publications and Presentations

A dynamical model of an animal’s nervous system, or synthetic nervous system (SNS), is a potentially transformational control method. Due to increasingly detailed data on the connectivity and dynamics of both mammalian and insect nervous systems, controlling a legged robot with an SNS is largely a problem of parameter tuning. Our approach to this problem is to design functional subnetworks that perform specific operations, and then assemble them into larger models of the nervous system. In this paper, we present networks that perform addition, subtraction, multiplication, division, differentiation, and integration of incoming signals. Parameters are set within each subnetwork to …

Biomechanical Testing Of An Exercise For Strengthening The Proximal Femur., Alyssa Osbourne

Electronic Theses and Dissertations

Based on the principles of cutting edge bone remodeling research, a unique therapeutic exercise device was designed specifically to improve bone quality at the most critical location of the proximal femur prone to fracture: the superior-lateral femoral neck where the fracture first initiates during a fall. The exercise/device is intended to work by inducing enough strain in the bone to stimulate the body’s natural bone remodeling mechanisms to increase bone density in the proximal femur and consequently prevent a fracture from arising if a fall to the side does occur.

In order to test the proposed exercise, experiments simulating the …

Optimization Of Prosthetic Hands: Utilizing Modularity To Improve Grip Force, Grasp, And Versatility, Jordan William Harris

UNLV Theses, Dissertations, Professional Papers, and Capstones

It has been demonstrated that although many varieties of upper limb prosthetics exist, commercially available prosthetics are outdated and unsatisfactory. Ineffectiveness and limitations have led to some prosthesis wearers having to own multiple devices, whereas others have given up on them entirely. Even though ample research has been conducted to design and test new hand designs, the industry appears to rest in an overall stagnated state.

It was proposed here, that one problem with prosthetic research is an excess of variables involved in testing, and therefore the improper application of the scientific method. It seems that each time a research …

Flow Characterization Under Idealized Stenosis Geometry And Performance Assessment Of The Hemodynamic Flow Facility, Marin Vratonjic

Electronic Thesis and Dissertation Repository

It is well known that regions inside the human arterial network susceptible to atherosclerosis experience a complex flow environment. Endothelial Cells (ECs) lining the inner wall of arteries are sensors to spatially and temporally varying shear stress (i.e. wall shear stress gradients). This complex force-loading can disrupt local cell-to-cell attachment regions triggering a cascade of biological events leading to the formation of atherosclerotic lesions. Consequently, researchers predominantly use a Parallel Plate Flow Chamber (PPFC) to study the hemodynamic-cell cycle relationship due to its simplicity and ability to achieve a two-dimensional fully-developed steady laminar flow across the cell monolayer. Researchers also …

The Effect Of Bone And Ligament Morphology Of Ankle Joint Loading In The Neutral Position, Jinhyuk Kim

Mechanical & Aerospace Engineering Theses & Dissertations

Computational modeling of joints is used to investigate the effect of injuries, to plan surgeries, and to answer questions about joints that cannot be answered experimentally. Existing models of the ankle joint are moving toward being able to model specific patients, however, they do not include all of the anatomy (e.g., bones and/or ligaments) and have restrictive boundary conditions. These simplification in anatomy are made to minimize pre-processing and computation time. Because biomechanical modeling is increasingly focused on the implementation of patient specific cases, the effects of including more anatomical structures and determining how they affect the model results is …

Self-Powered Ankle Prosthetic, Corina M. Espelien, Kelsey Pietzsch, Anna Sullivan

Mechanical Engineering

Originating from QL+'s customer requirements, the main technical specifications were to have 80% physiological range of motion, elastic energy return, impact absorption, and no external power sources. Based on the background research conducted and the discussions with experts in the field, the project team decided to focus on designing a prosthetic that focused on plantarflexion and dorsiflexion for a more comfortable gait. The main components of the final design are a hydraulic shock absorber, cam, torsion springs, heel, stopper, and separated keel. The heel, front and back keels, and stopper were manufactured out of carbon fiber. The link, lever, attachment …

A Computational Fluid Dynamics Study On Bidirectional Glenn Shunt Flow With An Additional Pulsatile Flow Through A Modified Blalock-Taussig Shunt, Seda Aslan

University of New Orleans Theses and Dissertations

The blood flow through the Bidirectional Glenn shunt (BGS) and modified Blalock-Taussig shunt (mBTS) to the pulmonary arteries (PAs) was analyzed using Computational Fluid Dynamics. This study consisted of the steady and pulsatile cases. In case one, the results of blood flow through the BGS for the Newtonian and non-Newtonian viscosity models were compared. Case two focused on having an additional pulsatile blood flow through the mBTS using the non-Newtonian Carreau viscosity model. The geometries were created based on the angiograms. In case one, boundary conditions to be specified at the inlets were obtained from the flow rate measurements via …

Design And Validation Of An In Vivo Long-Term Attachment Capsule Robot, Wanchuan Xie

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The invention of capsule endoscopy (CE) made the non-invasive monitoring of the entire small bowel possible and became the primary means for diagnosing small bowel pathology. In the last decade, capsule robots have been transformed from diagnostic devices into a widely studied biomedical platform with the potential for active locomotion, drug delivery and therapeutic capabilities. To perform accurate on-site drug release and therapy, it is necessary for a capsule robot to be able to attach to the intestinal tissue and maintain its position long-term. Design challenges derive from the task of long-term mucosal adhesion which requires firm, quick-response attachment without …

Development And Evaluation Of A Biocompatible Electroactive Sensor For Continuous Blood Pressure Measurement., Scott D. Cambron

Electronic Theses and Dissertations

Piezo-active composites have been implemented for sensing and transduction for decades. The 0-3 ceramic/polymer composite is one of the most common composite types used for sensing applications, owing to their tailorable properties of the two-phase composition, consisting of a three-dimensionally connected polymer/rubber matrix (inactive phase) with a dispersion of isolated piezo-ceramic particles (active phase). This thesis describes a method to develop novel biocompatible perivascular band comprised of a two-phase piezo-active composite to be fabricated using simple manufacturing processes. Biomaterials such as tissue scaffolds comprised of silk fibroin (SF) and chitosan (CS), and biocompatible soft rubbers will be implemented as the …

Kinematics Of The Lower Extremities During Fundamental Martial Arts Tricking Techniques, Kevin P. Grassie

Honors Scholar Theses

Martial Arts Tricking (MAT) is a relatively new sport that combines martial arts, gymnastics, acrobatics, and breakdancing for the purposes of creating aesthetic and impressive combinations of kicks, flips and twists. It has been growing exponentially through social media and the overall athletic and entertainment communities. The sport is very unique in that the movements, with their blended influences, provide novel ways for athletes to generate and utilize their momentum in a creative way. The results often include off-axis flips and twists, single-leg landings, and complicated yet fluid techniques that easily chain together.

Due to the sport only being a …

Robot Control For Remote Ophthalmology And Pediatric Physical Rehabilitation, Melissa Morris

FIU Electronic Theses and Dissertations

The development of a robotic slit-lamp for remote ophthalmology is the primary purpose of this work. In addition to novel mechanical designs and implementation, it was also a goal to develop a control system that was flexible enough to be adapted with minimal user adjustment to various styles and configurations of slit-lamps. The system was developed with intentions of commercialization, so common hardware was used for all components to minimize the costs. In order to improve performance using this low-cost hardware, investigations were made to attempt to achieve better performance by applying control theory algorithms in the system software. Ultimately, …

Estimation Of The Centre Of Mass From Motion Capture And Force Plate Recordings: A Study On The Elderly, Sebastien Cotton, Michele Vanoncini, Philippe Fraisse, Nacim Ramdani, Emel Demircan, Andrew P. Murray, Thierry Keller

Andrew P. Murray

The estimation of the centre of mass position in humans is usually based on biomechanical models developed from anthropometric tables. This method can potentially introduce errors in studies involving elderly people, since the ageing process is typically associated with a modification of the distribution of the body mass. In this paper, an alternative technique is proposed, and evaluated with an experimental study on 9 elderly volunteers. The technique is based on a virtual chain, identified from experimental data and locating the subject's centre of mass. Its configuration defines the location of the centre of mass, and is a function of …

Skin Strain Measurement To Predict Knee Joint Angles Through Nanocomposite Stain Gauges, Adin Martineau, James Tracy, Gavin Collins, Parker Rosquist, Dustin A. Bruening, Matt K. Seeley, David T. Fullwood, Anton E. Bowden

Biomedical Engineering Western Regional Conference

Explores the possibility of using high deflection nanocomposite strain gauges as knee joint angle sensor.