Mechanical Engineering Commons^™

Estimation Of Arterial Wall Parameters Via Model-Based Analysis Of Noninvasively Measured Arterial Pulse Signals, Dan Wang

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation presents a model-based method for estimating arterial wall parameters from noninvasively measured arterial pulse signals via a microfluidic-based tactile sensor. The sensor entails a polydimethylsiloxane (PDMS) microstructure embedded with 5×1 transducer array built on Pyrex/Polyethylene terephthalate (PET) substrate. The arterial pulse causes a time-varying deflection on the top of the PDMS microstructure, which registers as a resistance change by the transducer at the site of the artery.

Owing to the time-harmonic nature of its radial motion, the arterial wall is modeled as a second-order dynamic system. By combining this dynamic model with a hemodynamic model of blood flow, …

Review Of Educational Technology: Closing The Gap Between Modern Technology And The College Engineering Classroom, David Pinkerton, Krishna Pakala

Mechanical and Biomedical Engineering Faculty Publications and Presentations

This paper aggregates information from past and current studies regarding the implementation of technology in engineering classrooms and identifies the most promising ideas, technologies, and techniques. This paper provides insight into best practices for implementing technologies to improve the education of engineering students. This paper provides recommendations to adopt non-traditional teaching methods. Educational tools and techniques are evaluated on the basis of: Adoption and Assimilation, Access, Community, Intellectual Presence, Student Perception, and Development of Social and Professional Skills. Best practices are highlighted with descriptions of the technologies and techniques that were found most promising.

Developing And Testing Of An Upper Limb Exoskeleton For Stroke Patients, Drew Dudley, David Salazar

UNO Student Research and Creative Activity Fair

Objective: The main objective of this study was to determine functional and neuromuscular outcomes of stroke patients using their non-preferred hand with and without a 3D printed passive exoskeleton compared to controls using their non-preferred hand with and without the passive exoskeleton. Methods: Adults at least six months post stroke (Stroke, n = 5) and age- and sex- matched healthy controls (Control, n = 5) performed nine trials of a gross motor task while having their brain activity measured. The Fugl-Meyer and “Box and Block” test was used to measure the gross dexterity of the subjects with and without the …

Efficacy Of Assistive Devices Produced With Additive Manufacturing, James Pierce

UNO Student Research and Creative Activity Fair

Despite the frequency of musculoskeletal injuries such as sprains, broken bones and torn ligaments¹, treatment options are often costly, time-consuming and ill-fitted.^2,3 Additive manufacturing (“3D-printing) allows for the production of highly-customized and inexpensive assistive devices⁴, which suggests potential efficacy in the prescription of splints and casts for musculoskeletal injury.³ In the present study, a parametric, customizable splint/cast was created using a computer-aided design (CAD) package (Fusion 360, Autodesk, San Rafael, CA, USA) and produced with low-cost, desktop 3D printing (Ultimaker 2+ Extended, Ultimaker, Geldermalsen, Netherlands). Fitting of the devices was performed on five healthy …

Urea Functionalization Of Ultrasound-Treated Biochar: A Feasible Strategy For Enhancing Heavy Metal Adsorption Capacity, Baharak Sajjadi, James William Broome, Wei Yin Chen, Daniell L. Mattern, Nosa O. Egiebor, Nathan Hammer, Cameron L. Smith

Faculty and Student Publications

© 2018 Elsevier B.V. The main objective of a series of our researches is to develop a novel acoustic-based method for activation of biochar. This study investigates the capability of biochar in adsorbing Ni(II) as a hazardous contaminant and aims at enhancing its adsorption capacity by the addition of extra nitrogen and most probably phosphorous and oxygen containing sites using an ultrasono-chemical modification mechanism. To reach this objective, biochar physically modified by low-frequency ultrasound waves (USB) was chemically treated by phosphoric acid (H3PO4) and then functionalized by urea (CO(NH2)2). Cavitation induced by ultrasound waves exfoliates and breaks apart the regular …

Development Of A Counter-Flow Thermal Gradient Microfluidic Device, Shayan Davani

Doctoral Dissertations

This work presents a novel counter-flow design for thermal stabilization of microfluidic thermal reactors. In these reactors, precise control of temperature of the liquid sample is achieved by moving the liquid sample through the thermal zones established ideally through the conduction in the solid material of the device. The goal here is to establish a linear thermal distribution when there is no flow and to minimize the temperature change at flow condition. External convection as well as internal flowinduced effects influence the prescribed thermal distribution. The counter-flow thermal gradient device developed in this study is capable of both stabilizing the …

Hard, Soft And Off-The-Shelf Foot Orthoses And Their Effect On The Angle Of The Medial Longitudinal Arch: A Biplane Fluoroscopy Study, Megan E.R. Balsdon, Colin E. Dombroski, Kristen Bushey, Thomas Jenkyn

Mechanical and Materials Engineering Publications

Background: Foot orthoses have proven to be effective for conservative management of various pathologies. Pathologies of the lower limb can be caused by abnormal biomechanics such as abnormal foot structure and alignment, leading to inadequate support. Objectives: To compare biomechanical effects of different foot orthoses on the medial longitudinal arch (MLA) during dynamic gait using skeletal kinematics. Study Design: Prospective, cross-sectional study design. Methods: The MLA angle was measured for 12 participants among three groups: pes planus, pes cavus and normal arch. Five conditions were compared: three orthotic devices (hard custom foot orthosis (CFO), soft CFO, and off-the-shelf Barefoot Science©), …

Tailoring Materials Behavior Using Geometry, Hessein Ali, Hossein Ebrahimi, Ranajay Ghosh

EGS Content

Many applications require materials whose response can be tuned such as morphing wings for supermaneuverable vehicles, soft robotics and space structures. Nature achieves this objective using external dermal features – skin, furs, tooth, feathers. These nonlinearities are generated using the geometry and topology of the scales The scales provide distinct structural advantages such as protection and tailorable response from scales contact Scales also aid in highly dynamic life functions – such as locomotion, anti-fouling, flapping flights, swimming. Material to structural correlations are highly nonlinear due to scale topology. We aim to reveal structure-property-architecture correlations for automated 3D printed designs.

Estimation And Prediction Of The Human Gait Dynamics For The Control Of An Ankle-Foot Prosthesis, Guilherme Aramizo Ribeiro

Dissertations, Master's Theses and Master's Reports

With the growing population of amputees, powered prostheses can be a solution to improve the quality of life for many people. Powered ankle-foot prostheses can be made to behave similar to the lost limb via controllers that emulate the mechanical impedance of the human ankle. Therefore, the understanding of human ankle dynamics is of major significance. First, this work reports the modulation of the mechanical impedance via two mechanisms: the co-contraction of the calf muscles and a change of mean ankle torque and angle. Then, the mechanical impedance of the ankle was determined, for the first time, as a multivariable …

3d Printing In Low Resource Healthcare Settings: Analysis Of Potential Implementations, Alenna Beroza

Dissertations, Master's Theses and Master's Reports

3D printing has gained significant momentum in the past ten years, and its unique advantages make it especially ideal for use in low resource healthcare settings, where many designs have already been successfully implemented. Yet, little has been studied on how 3D printing can be sustainably and functionally implemented in low resource healthcare systems as a manufacturing practice. In this report, three business models are proposed for this implementation: In-House Operator, Independent Operator, and Print Farm. These models were then tested over four months in Kisumu county, Kenya, at two workshops and seven public hospitals. I worked with local medical …

Estimation Of Multi-Directional Ankle Impedance As A Function Of Lower Extremity Muscle Activation, Lauren Knop

Dissertations, Master's Theses and Master's Reports

The purpose of this research is to investigate the relationship between the mechanical impedance of the human ankle and the corresponding lower extremity muscle activity. Three experimental studies were performed to measure the ankle impedance about multiple degrees of freedom (DOF), while the ankle was subjected to different loading conditions and different levels of muscle activity. The first study determined the non-loaded ankle impedance in the sagittal, frontal, and transverse anatomical planes while the ankle was suspended above the ground. The subjects actively co-contracted their agonist and antagonistic muscles to various levels, measured using electromyography (EMG). An Artificial Neural Network …

A Hybrid-Powered Wireless System For Multiple Biopotential Monitoring, Shawn Li

Dissertations, Master's Theses and Master's Reports

Chronic diseases are the top cause of human death in the United States and worldwide. A huge amount of healthcare costs is spent on chronic diseases every year. The high medical cost on these chronic diseases facilitates the transformation from in-hospital to out-of-hospital healthcare. The out-of-hospital scenarios require comfortability and mobility along with quality healthcare. Wearable electronics for well-being management provide good solutions for out-of-hospital healthcare. Long-term health monitoring is a practical and effective way in healthcare to prevent and diagnose chronic diseases. Wearable devices for long-term biopotential monitoring are impressive trends for out-of-hospital health monitoring. The biopotential signals in …

Surf Leg, Samantha Campbell, Oyundari Altansukh, Caroline Swanson, Kurtis Barth

Mechanical Engineering

The Surf Leg Prosthetic project team in conjunction with QL+ and Operation Surf designed a transtibial prosthetic to be used for surfing. The senior project team focused on the missions of QL+ and Operation Surf as they went through the design process during the 2018-2019 academic year. The problem solved was that a standard prosthetic for a transtibial amputee does not provide the flexibility in enough degrees of freedom for a user to squat and balance on a surfboard. The goal of this project was to create a device specifically designed to improve the user’s balance and control while surfing. …

Design And Mechanical Characterization Of 3d Printed Gradient Porosity Poly(Propylene Fumarate) Scaffolds, Andrea Felicelli

Williams Honors College, Honors Research Projects

Worldwide incidence of bone disorders and conditions, an already prevalent problem, is expected to double by 2020 from the rate in 2013 due to factors such as higher life expectancies and lower levels of physical activity. Every year in the United States, over half a million patients receive bone defect repairs, with costs greater than $2.5 billion. Current repairs are typically done with bone grafts, which are often costly and can result in added complications in the donor surgical site. Tissue engineering, a growing field that seeks to assist and enhance tissue defect repairs through the use of synthetic materials, …

Recovery Of Stem Cell Proliferation By Low Intensity Vibration Under Simulated Microgravity Requires Linc Complex, H. Touchstone, R. Bryd, S. Loisate, M. Thompson, X. Pu, R. Beard, J. T. Oxford, G. Uzer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Mesenchymal stem cells (MSC) rely on their ability to integrate physical and spatial signals at load bearing sites to replace and renew musculoskeletal tissues. Designed to mimic unloading experienced during spaceflight, preclinical unloading and simulated microgravity models show that alteration of gravitational loading limits proliferative activity of stem cells. Emerging evidence indicates that this loss of proliferation may be linked to loss of cellular cytoskeleton and contractility. Low intensity vibration (LIV) is an exercise mimetic that promotes proliferation and differentiation of MSCs by enhancing cell structure. Here, we asked whether application of LIV could restore the reduced proliferative capacity seen …

Quantification Of Myocardial Mechanics In Left Ventricles Under Inotropic Stimulation And In Healthy Right Ventricles Using 3d Dense Cmr, Zhan-Qiu Liu

Theses and Dissertations--Mechanical Engineering

Statistical data from clinical studies indicate that the death rate caused by heart disease has decreased due to an increased use of evidence-based medical therapies. This includes the use of magnetic resonance imaging (MRI), which is one of the most common non-invasive approaches in evidence-based health care research. In the current work, I present 3D Lagrangian strains and torsion in the left ventricle of healthy and isoproterenol-stimulated rats, which were investigated using Displacement ENcoding with Stimulated Echoes (DENSE) cardiac magnetic resonance (CMR) imaging. With the implementation of the 12-segment model, a detailed profile of regional cardiac mechanics was reconstructed for …

Infection Control In Total Knee Replacement Prosthesis Using Nitric Oxide Releasing Biomaterials, Ashley Widing

Master's Theses

Replacing a weight-bearing joint is accompanied by long procedures, even longer recovery times, and intensive monitoring. This burden increases after infection; a complication requiring revision surgeries and therefore extensive additional recovery time. Infection can present itself at any time during the process, making it hard to predict. Currently, a two-part revision surgery is completed by removing all infected tissue and implanting an antibiotic spacer. The spacer fills the joint gap and is removed prior to the revision total knee replacement. A revision total knee replacement follows the same procedure as the initial surgery. Not only is this detrimental to patient …

A Biomimetic Approach To Controlling Restorative Robotics, Matthew T. Boots

Graduate Theses, Dissertations, and Problem Reports

Movement is the only way a person can interact with the world around them. When trauma to the neuromuscular systems disrupts the control of movement, quality of life suffers. To restore limb functionality, active robotic interventions and/or rehabilitation are required. Unfortunately, the primary obstacle in a person’s recovery is the limited robustness of the human-machine interfaces. Current systems rely on control approaches that rely on the person to learn how the system works instead of the system being more intuitive and working with the person naturally. My research goal is to design intuitive control mechanisms based on biological processes termed …