Biomedical Engineering and Bioengineering Commons^™

Structure-Property-Processing Analysis Of Graphene Bioscaffolds For Viability And Differentiation Of C2c12 Cells, Lynn Karriem

Boise State University Theses and Dissertations

We investigated the structure – property – processing correlation of graphene bioscaffolds produced using three different methods. Bioscaffolds were prepared by chemical vapor deposition (CVD), sublimation of Silicon Carbide (SiC), and printed solvent assisted exfoliated graphene ink. To gain insight into the roughness and topography of graphene, AFM was performed on each bioscaffold. Raman spectroscopy mapping demonstrated differences in the I_2D/I_G ratio for each scaffold. Young’s modulus was determined by nanoindentation and indicated that epitaxial graphene had the highest average stiffness, followed by CVD, with printed graphene demonstrating the lowest average stiffness. To investigate the biocompatibility of …

Tibial Compression During Activities Of Daily Living In Young And Older Adults, Elijah Miles Walker

Boise State University Theses and Dissertations

Introduction: Stress fracture, particularly in the tibia, is a growing concern among older adults (greater than 65 years). Older adults may have inherent stress fracture risk from ageing-related changes to their musculoskeletal system. Specifically, older adults reduced ankle neuromuscular function may impair their ability to attenuate repetitive compressive forces experienced during daily locomotor tasks and increase the likelihood of suffering bone damage from decreased bone tissue elasticity. Yet, it is currently unknown if older adults exhibit greater tibial compression than their younger counterparts during locomotor tasks. Purpose: This study sought to quantify tibial compression for older and younger adults when …

Predicting Surgical Outcome In Patients With Recurrent Patellar Dislocation, Dario De Caro

Boise State University Theses and Dissertations

Introduction

Lateral dislocation of the patella is a common injury in active adolescents and young adults. Patients who are ultimately managed surgically have a significantly lower risk of recurrent dislocation. However, determining the optimal surgical treatment remains a challenge, with patients sometimes undergoing multiple surgeries prior to successful stabilization. The aim of this study is to computationally evaluate patients that have undergone multiple surgeries to correct for recurrent lateral patellar dislocation and predict their clinical outcome.

Methods

Our patient cohort consisted of 16 patients with patella dislocation. Patient-specific imaging were used to create three-dimensional (3D) finite element (FE) models of …

Integrated Neuromusculoskeletal Modeling Within A Finite Element Framework To Investigate Mechanisms And Treatment Of Neurodegenerative Conditions, Victoria L. Volk

Boise State University Theses and Dissertations

Neurodegenerative and neurodevelopmental disorders are a group of conditions that stem from irregularities in the nervous system that lead to complications in function and movement. The goal of this work is to develop computational tools that: (1) measure the accuracy of surgical interventions in neurodegenerative and neurodevelopmental conditions, and (2) integrate neural and musculoskeletal frameworks to provide a platform to better investigate neurodegenerative and neurodevelopmental disorders. Parkinson’s disease (PD) is a neurodegenerative condition projected to affect over 1.2 million people by 2030 in the US. It is caused by atypical firing patterns in the basal ganglia region of the brain …

Role Of The Nuclear Envelope In The Mechanoregulation Adipogenesis, Matthew H. Goelzer

Boise State University Theses and Dissertations

Mechanical signals are known regulators of mesenchymal stem cell (MSC) fate, regulating their differentiation into osteoblasts, chondrocytes, and adipocytes. These relevant mechanical signals reach to nucleus through nuclear envelope proteins such as Lamin A/C and the Linker of the Nucleoskeleton and Cytoskeleton (LINC) complexes. Within the context of bone, clinically relevant mutations of Lamin A/C and the LINC complexes have been shown to alter adipogenic and osteogenic MSC differentiation patterns, suggesting that that nucleo-cytoskeletal connectivity provided by nuclear envelope is important in regulating MSC fate. Using MSC adipogenesis as a model of MSC mechanical regulation, the goal of this work …

Musculoskeletal Adaptation Of Young And Older Adults In Response To Environmental, Physical, And Cognitive Conditions, Amy E. Holcomb

Boise State University Theses and Dissertations

Accidental falls present a large functional and financial burden among people aged 65 years and older. Falls, injuries associated with falls, and the fear of falling decrease quality of life, physical function, and independence for older adults. To prevent falls, improve stability, and protect joints from damage or injury, the typical response to "challenging" conditions include cautious gait, increase muscle co-contraction, and decreased range of motion. These compensatory strategies are more pronounced in the older adult population with apprehensive "cautious" gait at slower speeds, decreased knee flexion, and increased muscle activation around the knee and ankle. The underlying mechanisms and …

3d Printable And Computational Models Of The Bone Marrow Mechanical Environment, Alexander Regner

Boise State University Theses and Dissertations

Aged individuals and astronauts experience bone loss despite rigorous physical activity. Bone mechanoresponse is in part regulated by mesenchymal stem cells (MSCs). We reported that daily low intensity vibration (LIV) restores MSC proliferation in senescence and simulated microgravity models, suggesting reduced mechanical signal delivery to MSCs likely contributes to declining bone mechanoresponse. To this end, we have developed a 3D bone marrow analog which controls trabecular geometry, marrow mechanics and external stimuli.

Finite element (FE) models of hydrogels, representing bone marrow, were generated using instantaneous compression (1000% strain/s, 20% strain) and relaxation experiments (100s) of both gelatin and hyaluronin-based hydrogels. …

Decellularization Of Porcine Cartilage Promotes Chondrogenic Differentiation Of Human Chondrocytes, Roxanne Nicole Stone

Boise State University Theses and Dissertations

Knee osteoarthritis (knee OA) is the most common type of osteoarthritis (OA) and accounts for 70% of arthritis-related hospital admissions and 23% of clinical visits. Major limitations in both the current non-surgical and surgical methods are that they only relieve pain and show no evidence for restoring natural tissue anatomy. Leaders in the field propose that a stem cell treatment approach holds promise for the regeneration of a greater proportion of hyaline-like tissue at the repair site. (Cross et al., 2014; Escobar Ivirico, Bhattacharjee, Kuyinu, Nair, & Laurencin, 2017; Helmick et al., 2008; Toh, Foldager, Pei, & Hui, 2014).

It …

A Computational Framework To Model Mesenchymal Stem Cell Nucleus Mechanics Using Confocal Microscopy, Zeke Kennedy

Boise State University Theses and Dissertations

The mechanical properties of the cell nucleus are emerging as a key component in genetic transcription. It has been shown that the stiffness of the nucleus in part regulates the transcription of genes in response to external mechanical stimuli. The stiffness has been shown to change as a result of both disease and changes to the external environment. While the mechanical structure of the nucleus can be visually documented using a confocal microscope, it is currently impossible to test the stiffness of the nucleus without a mechanical testing apparatus such as an atomic force microscope. This is problematic in that …

Low Intensity Vibrations Restore Nuclear Yap Levels And Acute Yap Nuclear Shuttling In Mesenchymal Stem Cells Subjected To Simulated Microgravity, Matt Thompson

Boise State University Theses and Dissertations

The bone deterioration that astronauts experience in microgravity environments is known to occur in response to the lack of gravity-based tissue stress. Mechanical forces are crucial to maintain healthy bone mass by regulating the function of bone-making osteoblasts as well as the proliferation and differentiation of their progenitors, mesenchymal stem cells (MSC) which replenish osteoblastic cells. Regulation of proliferative function of MSCs in response to mechanical force is in part controlled by the “mechanotransducer” protein YAP (Yes-associated protein) which is shuttled into the nucleus in response to mechanical challenge to induce gene expression necessary for cell proliferation. Our group had …

Controlling Strain Energy Density In 3d Cellular Collagen Constructs During Complex Loads, Katherine Hollar

Boise State University Theses and Dissertations

Mechanical stimulation applied to damaged soft tissues, such as ligament, can promote tissue remodeling to accelerate healing. To help identify treatments that encourage ligament healing, bioreactors have been designed to subject 3D cellularized constructs to various loading conditions in order to determine the mechanical mechanisms that trigger cell-mediated repair. An innovative approach is to use a bioreactor to apply controlled states of biaxial stress to study the effects of strain energy density and distortion energy on cell activity. Tissue distortion has been linked to changes in the structure and function of ligament, yet the specific impact of distortion energy on …

Effect Of Corrective Surgery On Lower Limb Mechanics In Patients With Crouch Gait, Adelle Milholland

Boise State University Theses and Dissertations

Crouch gait a progressively degrading gait deviation associated with the neurological disorder cerebral palsy. If left untreated it can lead to anterior knee pain and a loss of ambulation. At present there exists no agreed upon metric for determining the surgical procedures used to treat crouch gait and there is insufficient means to analytically compare the results of different procedures. The aims of this thesis work were to create a pipeline to transform a patient’s gait analysis data into a finite element model, develop a model of sufficient complexity to evaluate a range of outcomes by which to judge the …

The Effect Of Implant Conformity On Muscle Force Requirements In The Implanted Knee, Grace Mcconnochie

Boise State University Theses and Dissertations

Implant geometry is a significant factor in determining knee stability and patient satisfaction following total knee replacement (TKR). Ineffective muscle recruitment, impaired joint functionality and increased implant wear are consequences of an unstable knee replacement. Current knee laxity evaluation techniques are limited in their ability to account for the muscular response to knee instability. This study utilizes a subject specific lower-body musculoskeletal finite element (FE) model with dynamic muscle loading to evaluate implant laxity during activities of daily living. The effect of varying implant conformity on the muscle forces required to maintain a target kinematic profile during simulated laxity testing …

Development Of A Statistical Shape-Function Model Of The Implanted Knee For Real-Time Prediction Of Joint Mechanics, Kalin Gibbons

Boise State University Theses and Dissertations

Outcomes of total knee arthroplasty (TKA) are dependent on surgical technique, patient variability, and implant design. Non-optimal design or alignment choices may result in undesirable contact mechanics and joint kinematics, including poor joint alignment, instability, and reduced range of motion. Implant design and surgical alignment are modifiable factors with potential to improve patient outcomes, and there is a need for robust implant designs that can accommodate patient variability. Our objective was to develop a statistical shape-function model (SFM) of a posterior stabilized implant knee to instantaneously predict output mechanics in an efficient manner. Finite element methods were combined with Latin …

Studying The Applicability Of Biostimulated Calcite Precipitation In Stabilizing Expansive Soils, Md Touhidul Islam

Boise State University Theses and Dissertations

Of the four types of soils, clays are often associated with issues related to low bearing capacity, high compressibility, swelling and shrinking nature. For example, expansive soils swell and shrink with moisture ingress and digress and are prevalent in several parts of the world causing billions of dollars in damages annually to various civil infrastructures. Several ground improvement techniques such as chemical stabilization, deep soil mixing, moisture barriers, and others were employed to counteract these soils. However, these methods are impractical in certain situations and unsustainable in others due to their economic and environmental impacts. Microbiological treatment of soils could …

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 …

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 …

Development Of In-Vitro And In-Vivo Devices To Study The Mechanobiology Of Ligament Healing, John Bayard Everingham

Boise State University Theses and Dissertations

Ligament injuries are the most common sports injury in the United States. The current clinical practice for treating ligament injuries leaves many patients with significant pain and joint laxity for years following the initial injury. Controlled mechanical stimulation of the tissue after injury is necessary for robust healing, but the optimal mechanical environment for ligament healing is not fully understood. Alternative therapies, such as instrument assisted soft tissue mobilization (IASTM), offer a form of mechanical stimulation that is non-invasive and has shown promising clinical outcomes but the optimal dosage for IASTM treatments is unknown. The objective of this study was …

Analog Spiking Neuromorphic Circuits And Systems For Brain- And Nanotechnology-Inspired Cognitive Computing, Xinyu Wu

Boise State University Theses and Dissertations

Human society is now facing grand challenges to satisfy the growing demand for computing power, at the same time, sustain energy consumption. By the end of CMOS technology scaling, innovations are required to tackle the challenges in a radically different way. Inspired by the emerging understanding of the computing occurring in a brain and nanotechnology-enabled biological plausible synaptic plasticity, neuromorphic computing architectures are being investigated. Such a neuromorphic chip that combines CMOS analog spiking neurons and nanoscale resistive random-access memory (RRAM) using as electronics synapses can provide massive neural network parallelism, high density and online learning capability, and hence, paves …

Bi-Directional Fatigue Life Behavior Of Bovine Meniscus, Jaremy Creechley

Boise State University Theses and Dissertations

Meniscal injuries due to tissue tearing are prevalent in the U.S. yet the failure behavior of the meniscus is poorly understood. Clinical studies indicate that fatigue failure causes many of these tears. The highly circumferentially aligned fibers result in transversely isotropic material properties. Tears preferentially align bi-directionally to the fiber orientation. The aim of this study is to present the bi-directional fatigue life behavior of meniscal fibrocartilage. A novel fatigue life approach was developed to achieve this aim. Forty-eight bovine specimens were subjected to cyclic sinusoidal tension-tension stress at 2 Hz until rupture. Normalized peak tensile stresses were determined at …

Characterization And Feasibility Of A Portable Oxygen Concentrator For Use With A Mass Casualty Ventilator, Paul Robert Williams

Boise State University Theses and Dissertations

The American Association for Respiratory Care has reported a need to stockpile 5,000-10,000 mass casualty ventilators with supplemental oxygen in preparation for pandemic emergencies (1). The American Medical Association specifies oxygen concentrators supply oxygen at 5 liters per minute at ≥90% purity (2). However, these design specifications may not be the most efficient use of system resources in portable oxygen concentrators using pressure swing adsorption. A testbed was developed to investigate the system performance of an oxygen concentrator while altering the system inlet and outlet pressures and flow rates. This investigation demonstrates that a more efficient portable oxygen concentrator, which …

Toward Characterization Of Diseased Vascular Structures Using Noncontact Photoacoustic And Laser-Ultrasound Imaging: A Phantom Study, Jami Lynne Johnson

Boise State University Theses and Dissertations

Visualizing and characterizing atherosclerotic plaques is important in determining the vulnerability of a plaque to rupture. To evaluate rupture risk, several compositional factors should be evaluated, including inflammation, the presence and size of lipid pools, thickness of the fibrous cap, and calcification. Currently, a need exists for an imaging modality that can detect each of these factors in a safe, noninvasive manner with high resolution and contrast at clinically relevant depths. Photoacoustic imaging is a growing field that has the potential to improve plaque diagnosis. Spectroscopic methods have shown promise toward detection of constituents of plaque with unique optical absorption …

Using The Continuous Wavelet Transform To Characterize Differences Between Impact Signals From Non-Cleated And Cleated Turf Shoes, Wayne Robert Fischer

Boise State University Theses and Dissertations

The continuous wavelet transform was used to characterize the time-frequency differences between impact forces from non-cleated and cleated turf shoes among male football athletes who perform cut and run activities. This research is significant because it elucidates how athletes experience different impact force and torque frequency content based on the type of shoe they are wearing. The complex Morlet mother wavelet was used to analyze all ground reaction force and vertical ground reaction moment signals to create time-frequency power spectrum plots. For each signal, a statistical confidence interval was calculated and displayed along with the cone of influence caused by …