3d Printed Force Transducers For In-Vitro Mitral Valve Chordae Tendineae Force Measurements,
2018
University of Arkansas, Fayetteville
3d Printed Force Transducers For In-Vitro Mitral Valve Chordae Tendineae Force Measurements, Hayley Chandler
Biomedical Engineering Undergraduate Honors Theses
Mitral valve surgery is incredibly prevalent in the United States with more than 40,000 mitral valve surgical procedures annually. Improving the imaging techniques used to diagnose these cases requires validation of 3D models through experimental data such as mechanical properties of the tissue. An essential part of this process for the mitral valve is measuring the force experienced by chordae tendineae. This has been achieved with brass force transducers but using a 3D printed design can have many benefits. In this study, 3D printed miniature c-shaped force transducers comparable to previous metal models were designed and created using Solidworks 2016. …
Investigating The Likelihood Of Pediatric Femur Fracture Due To Falls Through Finite Element Analysis.,
2018
University of Louisville
Investigating The Likelihood Of Pediatric Femur Fracture Due To Falls Through Finite Element Analysis., Keyonna Mckinsey
Electronic Theses and Dissertations
Bone fracture is the second most common injury of child abuse. Studies have generally reported that femur fractures are more likely due to abuse than accidental causes in cases where the child is non-ambulatory. They have also found that household falls are commonly offered as the cause of injury in cases of abuse. In this study, a finite element (FE) pediatric femur model will be developed and used to evaluate likelihood of fracture in common household fall scenarios (bed falls and feet first falls). This will provide greater biomechanical evidence as to the likelihood of femur fracture due to common …
Sex Differences In Lower Limb Biomechanics During A Single-Leg Cut With Body Borne Load,
2018
Boise State University
Sex Differences In Lower Limb Biomechanics During A Single-Leg Cut With Body Borne Load, Auralea Carylon Fain
Boise State University Theses and Dissertations
Introduction: Musculoskeletal injuries are ever-increasing in military personnel, particularly females. These musculoskeletal injuries are attributed to adaptations in lower limb biomechanics while performing routine military tasks, such as a single-leg cut, with the addition of body borne load. However, it is unknown if females and males exhibit similar lower limb biomechanics with the addition of body borne load during these tasks. This study sought to compare the lower limb biomechanical adaptations exhibited by females and males performing a single-leg cut with body borne load. Methods: Eleven females and 17 males had lower limb biomechanics quantified during a single-leg cut with …
Effects Of Stride Length On Lower Limb Stiffness When Running With Body Borne Load,
2018
Boise State University
Effects Of Stride Length On Lower Limb Stiffness When Running With Body Borne Load, Nick Lobb
Boise State University Theses and Dissertations
Introduction: During military activities, soldiers are often required to run at a fixed cadence with body borne load, but these loads purportedly increase leg stiffness, leading to increased risk of musculoskeletal injury. Yet, to date, it is unknown how altering stride length when running with body borne load affects lower limb stiffness for males and females. Purpose: To quantify leg stiffness, and lower limb joint (hip, knee and ankle) stiffness for males and females using different stride lengths to run with body borne loads of 20 kg, 25 kg, 30 kg, and 35 kg. Methods: Twenty-seven (17 males and 10 …
The Effect Of Elastin Degradation On The Biomechanical Properties Of Porcine Aortic Tissue,
2018
University of Arkansas, Fayetteville
The Effect Of Elastin Degradation On The Biomechanical Properties Of Porcine Aortic Tissue, Caleb Nissen
Biomedical Engineering Undergraduate Honors Theses
The rupture of abdominal aortic aneurysms (AAA) is currently the 13th leading cause of death in the United States [1]. AAA is characterized, in part, by an increase in presence of proteolytic enzymes which degrade the structural proteins collagen and elastin [6]. The goal of this study was to examine the effect that elastin degradation has on the biomechanical properties of aortic tissue. For this experiment, porcine aortic tissue was cut in the circumferential and longitudinal directions. These specimens were exposed to an elastase solution for varying time-intervals and then underwent uniaxial tensile testing. Elastase-treated tissue tested in the …
Extraction And Analysis Of Vector Flow Imaging Data In A Pediatric Population,
2018
University of Arkansas, Fayetteville
Extraction And Analysis Of Vector Flow Imaging Data In A Pediatric Population, Bailey Stinnett
Biomedical Engineering Undergraduate Honors Theses
Vector flow imaging (VFI) is a new ultrasound technology that provides real time, angle-independent visualization of flow velocities in the heart and great vessels. Thus far, VFI has been used for superficial applications due to the limited penetration depth of available transducer probes; however, this depth in smaller pediatric patients enables adequate aortic views. In this project, VFI was used to study pediatric aortic stenosis (PAS)—a congenital heart defect that results in the narrowing of the aorta and/or aortic valve. The decision to refer PAS patients for surgical or catheter-based intervention is initially based on Doppler ultrasound. VFI is potentially …
Effects Of Hydration And Mineralization On The Mechanical Behavior Of Collagen Fibrils,
2018
University of Arkansas, Fayetteville
Effects Of Hydration And Mineralization On The Mechanical Behavior Of Collagen Fibrils, Marco Fielder
Graduate Theses and Dissertations
Bone is a composite biomaterial with a structural load-bearing function. Understanding the biomechanics of bone is important for characterizing factors such as age, trauma, or disease, and in the development of scaffolds for tissue engineering and bioinspired materials. At the nanoscale, bone is primarily composed of collagen protein, apatite crystals, and water. Though several studies have characterized nanoscale bone mechanics as the mineral content changes, the effect of water, mineral, and carbon nanotube (CNT) content and distribution in fibril gap and overlap regions is unexplored. This study used molecular dynamics to investigate the change in collagen fibril deformation mechanisms as …
Novel Methodology For Emboli Analog Production And In-Vitro Simulation Of Acute Ischemic Stroke,
2018
University of Arkansas, Fayetteville
Novel Methodology For Emboli Analog Production And In-Vitro Simulation Of Acute Ischemic Stroke, Anne Preut
Graduate Theses and Dissertations
Stroke is the leading cause of disability and a primary cause of mortality, resulting in an estimated $33 billion dollars spent on healthcare, rehabilitation and lost productivity in the United States each year. The most prevalent cause of stroke incidents are acute ischemic events, manifested as blood clots in the vasculature supplying the brain. Current gold standard treatments have improved since 2006 with the introduction of mechanical stent retrievers; however, several issues with the current treatments to acute ischemic stroke remain. Thrombolysis of the clot with a tissue plasminogen activator may lead to weakening the vessel wall and consequently, hemorrhaging. …
Integration Of A Sensory Driven Model For Hand Grasp Function In 3d Printed Prostheses,
2018
University of South Carolina
Integration Of A Sensory Driven Model For Hand Grasp Function In 3d Printed Prostheses, Austin T. Hetherington
Senior Theses
My Honors Thesis was completed through the Biomedical Engineering senior design project I worked on. Our project took a mechanically operated 3D printed prosthetic hand and automated the process by which it makes a grasp. The purpose of this project was to provide an affordable, automatic prosthetic hand to those either capable and incapable of wrist flexion. The current 3D printed prosthetic models require users to bend their wrist to initiate a simple grasp. However, our design took an alternative approach by using an EMG sensor placed on the ventral side of the forearm to record muscle activity, which, upon …
Increasing Drug Delivery Efficacy Of Drug-Coated Balloons,
2018
University of South Carolina
Increasing Drug Delivery Efficacy Of Drug-Coated Balloons, Alexander Galan, Eric Bidinger, Franco Godoy, Shrusti Patel
Senior Theses
Peripheral artery disease (PAD), the narrowing of peripheral arteries located in areas such as the arms and legs, is a common disease that affects 12% to 20% of people over 65. Numerous therapies have been developed to treat PAD, the most recent technology being drug-coated balloons. Drug-coated balloons release drugs, such as Paclitaxel (PTX), into the arterial wall during balloon angioplasty to locally treat PAD. Current levels of drug transfer from the balloon to the vascular endothelium are at a low 10%-18%. Our Biomedical Engineering Senior Design project aims to increase drug delivery of drug-coated balloons by manipulating the clinically-controllable …
Can The Presence Of A 1/F Structure In Stride-To-Stride Variability Enable Us To Withstand Falls?,
2018
University of Nebraska at Omaha
Can The Presence Of A 1/F Structure In Stride-To-Stride Variability Enable Us To Withstand Falls?, Jenny A. Kent, Andreas Skiadopoulos, Jordan Wickstrom, Nikolaos Stergiou
UNO Student Research and Creative Activity Fair
Falls are a persistent threat to longevity and quality of life, affecting 1/3 of older adults living in the community each year. There is strong evidence suggesting that a particular pattern within our walking reflects an ability to adapt to a continually changing environment. Specifically, the stride-to-stride patterns of healthy walking have a 1/f frequency spectrum. This has been observed to degrade to varying extents with aging and pathology. The aim of this study was to determine whether the presence of this structure of variability is related to an increased ability to withstand perturbations. We hypothesized that individuals who demonstrated …
Individuals With Peripheral Artery Disease Alter Spatiotemporal Gait Parameters When Walking With Pain Versus Without Pain,
2018
University of Nebraska at Omaha
Individuals With Peripheral Artery Disease Alter Spatiotemporal Gait Parameters When Walking With Pain Versus Without Pain, Todd Leutzinger, Sara A. Myers, Iraklis Pipinos
UNO Student Research and Creative Activity Fair
This abstract compares the spatiotemporal walking parameters of individuals with peripheral artery disease at the time they first begin walking, the time when they first feel pain, and the time when they can no longer continue walking.
Eigenstrain As A Mechanical Set-Point Of Cells,
2018
University of Nebraska-Lincoln
Eigenstrain As A Mechanical Set-Point Of Cells, Shengmao Lin, Marsha C. Lampi, Cynthia A. Reinhart-King, Gary C.P. Tsui, Jian Wang, Carl A. Nelson, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
Cell contraction regulates how cells sense their mechanical environment. We sought to identify the set-point of cell contraction, also referred to as tensional homeostasis. In this work, bovine aortic endothelial cells (BAECs), cultured on substrates with different stiffness, were characterized using traction force microscopy (TFM). Numerical models were developed to provide insights into the mechanics of cell–substrate interactions. Cell contraction was modeled as eigenstrain which could induce isometric cell contraction without external forces. The predicted traction stresses matched well with TFM measurements. Furthermore, our numerical model provided cell stress and displacement maps for inspecting the fundamental regulating mechanism of cell …
Effects Of Backpack Type On Kinematics Of The Lower Back During Walking And Jogging,
2018
University of Kentucky
Effects Of Backpack Type On Kinematics Of The Lower Back During Walking And Jogging, Cazmon Suri
Theses and Dissertations--Biomedical Engineering
Heavy backpacks have been suggested to have a pathogenic role in experience of low back pain among children. We have conducted a repeated-measure study to investigate the backpack-induced changes in lumbo-pelvic coordination of forty gender-balanced college age students when they walked and jogged on a treadmill with two different types of backpacks: normal and ergonomically modified. The backpack-induced changes in lumbo-pelvic coordination were larger when carrying an ergonomically modified vs. a normal backpack as well as when jogging versus walking. The larger changes in lumbo-pelvic coordination when carrying an ergonomically modified backpack were likely due to kinematic restraints imposed by …
Characterizing The Effects Of High-Intensity Exercise On Balance And Gait Under Dual-Task Conditions In Parkinson’S Disease,
2018
Cleveland State Community College
Characterizing The Effects Of High-Intensity Exercise On Balance And Gait Under Dual-Task Conditions In Parkinson’S Disease, El Iva Baron
ETD Archive
Parkinson’s disease (PD) is a neurodegenerative disorder, characterized by four cardinal motor symptoms including bradykinesia, tremor, rigidity, and postural instability, and non-motor symptoms including cognitive impairment. Daily activities, such as walking and maintaining balance, are impacted due to impairments in motor function, and are further exacerbated with the addition of cognitive loading, or dual-tasking (DT). High-intensity exercise has demonstrated centrally-mediated improvements of PD symptoms, with additional positive effects on overall health. The goal of this project was to identify changes in dynamic balance recovery and gait function under conditions with and without increased cognitive load after a high-intensity exercise intervention …
Neuromuscular Reflex Control For Prostheses And Exoskeletons,
2018
Cleveland State University
Neuromuscular Reflex Control For Prostheses And Exoskeletons, Sandra K. Hnat
ETD Archive
Recent powered lower-limb prosthetic and orthotic (P/O) devices aim to restore legged mobility for persons with an amputation or spinal cord injury. Though various control strategies have been proposed for these devices, specifically finite-state impedance controllers, natural gait mechanics are not usually achieved. The goal of this project was to invent a biologically-inspired controller for powered P/O devices. We hypothesize that a more muscle-like actuation system, including spinal reflexes and vestibular feedback, can achieve able-bodied walking and also respond to outside perturbations. The outputs of the Virtual Muscle Reflex (VMR) controller are joint torque commands, sent to the electric motors …
Feasibility Of Using An Equilibrium Point Strategy To Control Reaching Movements Of Paralyzed Arms With Functional Electrical Stimulation,
2018
Clevleand State University
Feasibility Of Using An Equilibrium Point Strategy To Control Reaching Movements Of Paralyzed Arms With Functional Electrical Stimulation, Matthew Huffman
ETD Archive
Functional electrical stimulation (FES) is a technology capable of improving the quality of life for those with the loss of limb movement related to spinal cord injuries. Individuals with high-level tetraplegia, in particular, have lost all movement capabilities below the neck. FES has shown promise in bypassing spinal cord damage by sending electrical impulses directly to a nerve or muscle to trigger a desired function. Despite advancements in FES, full-arm reaching motions have not been achieved, leaving patients unable to perform fundamental tasks such as eating and grooming. To overcome the inability in current FES models to achieve multi-joint coordination, …
Predictive Simulations Of Gait And Their Application In Prosthesis Design,
2018
Cleveland State University
Predictive Simulations Of Gait And Their Application In Prosthesis Design, Anne D. Koelewijin
ETD Archive
Predictive simulations predict human gait by solving a trajectory optimization problem by minimizing energy expenditure. These simulations could predict the effect of a prosthesis on gait before its use. This dissertation has four aims, to show the application of predictive simulations in prosthesis design and to improve the quality of predictive simulations. Aim 1 was to explain joint moment asymmetry in the knee and hip in gait of persons with a transtibial amputation (TTA gait). Predictive simulations showed that an asymmetric gait required less effort. However, a small effort increase yielded a gait with increased joint moment symmetry and reduced …
Can A Comprehensive Transition Plan To Barefoot Running Be The Solution To The Injury Epidemic In American Endurance Runners?,
2018
Claremont McKenna College
Can A Comprehensive Transition Plan To Barefoot Running Be The Solution To The Injury Epidemic In American Endurance Runners?, Michael A. Scarlett
CMC Senior Theses
Fossils belonging to the genus Homo, dating as far back as two million years ago, exhibit uniquely efficient features suggesting that early humans had evolved to become exceptional endurance runners. Although they did not have the cushion or stability-control features provided in our modern day running shoes, our early human ancestors experienced far less of the running-related injuries we experience today. The injury rate has been estimated as high as 90% annually for Americans training for a marathon and as high as 79% annually for all American endurance runners. There is an injury epidemic in conventionally shod populations that …
Asymmetric Patterns Of Small Molecule Transport After Nanosecond And Microsecond Electropermeabilization,
2018
Old Dominion University
Asymmetric Patterns Of Small Molecule Transport After Nanosecond And Microsecond Electropermeabilization, Esin B. Sözer, C. Florencia Pocetti, P. Thomas Vernier
Bioelectrics Publications
Imaging of fluorescent small molecule transport into electropermeabilized cells reveals polarized patterns of entry, which must reflect in some way the mechanisms of the migration of these molecules across the compromised membrane barrier. In some reports, transport occurs primarily across the areas of the membrane nearest the positive electrode (anode), but in others cathode-facing entry dominates. Here we compare YO-PRO-1, propidium, and calcein uptake into U-937 cells after nanosecond (6 ns) and microsecond (220 µs) electric pulse exposures. Each of the three dyes exhibits a different pattern. Calcein shows no preference for anode- or cathode-facing entry that is detectable with …
