Biomedical Engineering and Bioengineering Commons^™

Biomechanical Analysis Of Ligament Modelling Techniques And Femoral Component Malrotation Following Tka, Liam A. Montgomery

Electronic Thesis and Dissertation Repository

Previous studies have demonstrated that satisfaction and revision rates following total knee arthroplasty (TKA) are lower than those of comparable surgeries such as total hip replacements. A leading cause for these revisions is joint instability which may be due to improper ligament balancing or poorly aligned surgical implants. One of the methods used to investigate biomechanical forces and kinematics is computational modelling of the post-operative TKA knee.

A unique knee model was used to investigate the biomechanical and kinematic effects of ligament model complexity, as well as the effects of simulating ligament wrapping versus ignoring ligament wrapping. We then used …

The Use Of Ct To Assess Shoulder Kinematics And Measure Glenohumeral Arthrokinematics, Baraa Daher

Electronic Thesis and Dissertation Repository

Recently, studies have started employing dynamic four-dimensional computed tomography (4DCT) imaging as a biomechanical assessment tool. These studies would benefit from the valuable work that has been done in the past using three-dimensional computed tomography (3DCT). Thus, a structured review was conducted to examine the extent and range of methods employing CT imaging to measure shoulder kinematics. The findings of the review were utilized to conduct a study that employed 4DCT imaging to measure glenohumeral joint congruency and arthrokinematics during internal rotation to the back in a population of healthy individuals. The results of this work show the importance of …

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 …

Subtalar Joint Definition In Biomechanical Models, Julia Noginova

Biomedical Engineering Theses & Dissertations

The effect of including a subtalar joint in a dynamic musculoskeletal model has not been fully explored or validated. The subtalar joint is often modeled as a one DOF hinge with the tri-planar axis defined as a combination of inclination and deviation angles measured from the ground and midline of the foot, respectively. The overall purposes of this dissertation were to explore how the inclusion of the subtalar joint and the definition of origin location and axis orientation affect the kinematics, joint kinetics, and muscle activations of the knee, ankle, and subtalar joint during dynamic tasks of walking and running …

A Novel Intervention To Prevent Post-Traumatic Osteoarthritis Following Knee Joint Injury, Gerardo E. Narez

Doctoral Dissertations

The knee joint is the most commonly injured body part in the human body. Injuries as a result of participation in sports, or other recreational activities, often leads to damage to the anterior cruciate ligament (ACL) and meniscus. Injury to these tissues is strongly associated with subsequent knee post-traumatic osteoarthritis (PTOA), which is considered a serious disease because it greatly impacts a patient’s quality of life and significantly increases their risk of premature death. To return stability to the joint, the current clinical treatment is to perform reconstruction of the torn ACL and a meniscal debridement, or meniscectomy, when needed. …

Cfd Analysis Of Subcutaneous Deposition And Dispersion Of Insulin In Adipose Tissue, Ryan C. Lubbers

Masters Theses

Drug delivery is the most important factor of many therapies, but a lack of technology and research have led to a very generalized understanding of drug kinetics. Insulin pump therapy for the treatment of Type 1 Diabetes depends on precise delivery of the hormone into the adipose region between the dermis and underlying muscle. The kinetics of insulin within the adipose tissue environment is not well understood and varies greatly case to case. The use of computation fluid dynamics (CFD) models to study insulin kinetics in relation to influential factors will lead to a better understanding of the characteristics of …

Development Of A Novel Haptic Feedback System For Gait Training Applications, Mohsen Alizadeh Noghani

Electronic Theses and Dissertations

Until recently, study and correction of motor or gait functions required costly sensors and measurement setups (e.g., optical motion capture systems) which were only available in laboratories or clinical environments. However, due to (1) the growing availability and affordability of inertial measurement units (IMUs) with high accuracy, and (2) progress in wireless, high bandwidth, and energy-efficient networking technologies such as Bluetooth Low Energy (BLE), it is now possible to measure and provide feedback in real-time for biomechanical parameters outside of those specialized settings. To enable gait training without an expert who can provide verbal feedback, augmented feedback, which is divided …

Bilateral Ground Reaction Force Jumping Asymmetry And Performance, Keith Painter

Electronic Theses and Dissertations

The prevalence of asymmetry in performance research has increased in recent years with mixed results. Much of the performance research has focused on unilateral jumping activities attempting to show relationships to other performance variables. However, bilateral ground reaction forces (bGRF) from jumps are more frequently assessed in athlete monitoring programs and the asymmetry from those jumps could be a simple addition to data already being collected. Research into bGRF asymmetries is lacking and no studies have addressed longitudinal changes. Additionally, research into the relationship of asymmetries to performance have infrequently used athletes. For these reasons, this dissertation will focus on …

Subclinical Atherosclerosis Quantified Through Cumulative Shear Measurement, Margaret Lynne Papka

Master's Theses

With the high mortality rate of cardiovascular disease, it is important to study the early signs. The early detection of cardiovascular disease can lead to saved lives. Currently the most prevalent detection methods are the Framingham Risk Score and the carotid intima media thickness, both of which are insufficient. The necessary tool for early detection requires a uniform quantification system. The stimulus leading to endothelial dysfunction, the most significant predictor of a major adverse cardiovascular event (MACE)—and subsequently subclinical atherosclerosis—is reduced shear stress. Increased surface relative roughness affects the flow profile transition from laminar to turbulent resulting in reduced shear …

Enhancing Biomechanical Function Through Development And Testing Of Assistive Devices For Shoulder Impairment And Total Limb Amputation, Patrick Hall

Doctoral Dissertations

Assistive devices serve as a potential for restoring sensorimotor function to impaired individuals. My research focuses on two assistive devices: a passive shoulder exoskeleton and a muscle-driven endoprosthesis (MDE). Previous passive shoulder exoskeletons have focused on testing during static loading conditions in the shoulder. However, activities of daily living are based on dynamic tasks. My research for passive shoulder exoskeletons analyzes the effect that a continuous passive assistance has on shoulder biomechanics. In my research I showed that passive assistance decreases the muscular activation in muscles responsible for positive shoulder exoskeleton. An MDE has the potential to have accurate and …

Influence Of Extracellular Matrix Stiffness And Topography On Neuronal Cell Behavior And Neurite Outgrowth, Mohan Yasodharababu

Graduate Theses and Dissertations

The focus of regeneration therapy for traumatic brain injuries and Alzheimer's disease is on the promotion and growth of neuronal cells. In vitro research attempts to improve this by modifying the stiffness and topography of the extracellular matrix (ECM). However, the limitations of in vitro experiments make it difficult to control the individual factors influencing neuronal cell growth. A computational model can be used to decouple individual factors and study them individually to gain a better understanding of the mechanics between the neuronal cell and ECM, which will aid in the design of in vitro experimental studies.

This study develops …

Electrohydrodynamic Simulations Of Capsule Deformation Using A Dual Time-Stepping Lattice Boltzmann Scheme, Charles Leland Armstrong

Mathematics & Statistics Theses & Dissertations

Capsules are fluid-filled, elastic membranes that serve as a useful model for synthetic and biological membranes. One prominent application of capsules is their use in modeling the response of red blood cells to external forces. These models can be used to study the cell’s material properties and can also assist in the development of diagnostic equipment. In this work we develop a three dimensional model for numerical simulations of red blood cells under the combined influence of hydrodynamic and electrical forces. The red blood cell is modeled as a biconcave-shaped capsule suspended in an ambient fluid domain. Cell deformation occurs …

Classifying Common Knee Rehabilitation Exercise Mistakes Using Imu Data, Fedor Myagkov

Dartmouth College Undergraduate Theses

Physical therapy following major surgeries is a branch of medicine that has seen its fair share of technologically inspired advances. One important facet of physical therapy, the “at-home exercises” patients are prescribed to do, is still somewhat of a “black box” to many physical therapists (PTs). PTs have no way of knowing (1) whether the patient is doing the home exercises, or (2) whether the patient is doing the exercises in the correct and healthy manner. This lack of awareness makes it difficult for the PT to guide the patient, which can often lead to prolonged rehabilitation periods or (sometimes) …

Device For Affixation Of Rear-Facing Child Restraint System To Ambulance Cot For Non-Emergent Transport, Matthew Miller, Kendall Rogoff, Troy Kohler, Lily Buchanan

Honors Theses

During motor vehicle travel it is a near-universal practice to transport infants in a rear-facing car seat, formally known as a child restraint system (CRS). Car seats are subject to heavy regulations, extensive testing, and are safe, secure, and familiar environments for infants. The use of a CRS reduces fatalities associated with motor vehicle collisions by up to 71%. Current devices on the market for pre-hospital infant transport are harness-based and do not utilize these car seats. Aversion to use of these harnesses occurs for a variety of reasons. The device becomes visually unattractive after remaining in storage for long …

Is The Walking Pattern Similar Between Slope Walking And Obstacle Negotiation?, Jiani Lu

Theses & Dissertations

Studying biomechanical characteristics of human motion sheds light on the motor control strategies in the central nervous system. Slope walking and obstacle negotiation appear to have some similarities in control strategies based on subjective observation, but these two motions have never been compared objectively in biomechanics literature. This study aimed to investigate the similarities between obstacle negotiation and slope walking in kinematics and muscle activity. The similarities were determined by the correlation of the maximum heel elevation and muscle co-activation index between obstacle negotiation and inclined treadmill walking. The strength of correlation was compared in four different pairs of conditions: …

Developing Aligned Nerve Scaffolds In A 3d Type-I Collagen Gel, Gabriel David

Biomedical Engineering Undergraduate Honors Theses

Despite significant progress in the field of peripheral nerve repair, clinical success is still limited, leaving millions to suffer from peripheral neuropathy with billions spent every year for treatment. Nerve repair methods that are capable of maximizing the regenerative properties of peripheral nerves are greatly desired in the field of medical science. This research aims to fill the gap between modern methods and the future of nerve repair by creating type-I collagen scaffolds with aligned degradation pores that will assist and nurture nerves growing through them. This is achieved by incorporating adipose stem cells into type-I collagen hydrogels and aligning …

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. …

New Force Transducer For Mitral Valve Chordae Tendinea, Joseph Berryman

Biomedical Engineering Undergraduate Honors Theses

In order to inform the future of mitral valve repair and replacement, more investigation into the mechanics of the sub-valvular structure is needed. Understanding the roles of each chord during valve closure requires a sensor capable of detecting these small forces with enough sensitivity to determine the characteristics of each of the chordal types. The focus of the cantilever force transducer is to maximize this sensitivity while also minimizing the invasiveness of the sensor on the overall function of the chord. The design utilizes flexible yet strong 3D printed resin and cantilever arms to improve the strain exerted on a …

Static Force Analysis Of A Porcine Mitral Valve To Determine Self-Supporting Capabilities Of The Leaflets, Jacob Paris

Biomedical Engineering Undergraduate Honors Theses

The mitral valve (MV) is responsible for controlling the flow between the left atrium (LA) and left ventricle (LV). This includes maintaining valve closure under high systolic pressures. Mitral regurgitation (MR) occurs when the valve fails to completely close and blood flows in the reverse direction, from the LV to the LA, during ejection. This type of valvular heart disease is prevalent among elderly individuals and is becoming increasingly common as the population ages. In order to better understand how to properly treat this large group of affected individuals, the mechanics of the MV during high systolic pressures must be …

A Generalized Method For Predictive Simulation-Based Lower Limb Prosthesis Design, Mark Price

Doctoral Dissertations

Lower limb prostheses are designed to replace the functions and form of the missing biological anatomy. These functions are hypothesized to improve user outcome measures which are negatively affected by receiving an amputation – such as metabolic cost of transport, preferred walking speed, and perceived discomfort during walking. However, the effect of these design functions on the targeted outcome measures is highly variable, suggesting that these relationships are not fully understood. Biomechanics simulation and modeling tools are increasingly capable of analyzing the effects of a design on the resulting user gait. In this work, prothesis-aided gait is optimized in simulation …

Drive Leg And Stride Leg Ground Reaction Forces Relationship To Medial Elbow Stress And Velocity In Collegiate Baseball Pitchers, Brett Smith

Biomedical Engineering Theses & Dissertations

This study examines several different kinetic variables in relation to pitch velocity and elbow varus torque in collegiate baseball pitchers using force plates, an inertial measurement unit, and a radar unit. The purpose of this study is to investigate the kinetic variables being measured and their relationship to pitch velocity and loads being placed on the medial elbow. Twelve collegiate baseball pitchers participated in this study, which was approved by the IRB. Impulse of the drive leg in the anterior-posterior direction, stride leg peak force in the anterior-posterior (AP) direction, elbow varus torque, and pitch velocity were all measured. Two …

In Vitro Analyses Of The Contributions Of The Hip Capsule To Joint Biomechanics, Emma Donnelly

Electronic Thesis and Dissertation Repository

Optimal management of the hip capsule during arthroscopic surgery has not been established. The impact of incisions made to the capsule during minimally invasive procedures on joint biomechanics, and whether repair provides any benefit, continue to be debated. The effectiveness of capsular repair to restore native kinematics may be insufficient. Therefore, a better understanding of joint behavior during various capsule conditions is needed. A new robotic system was used to analyze the effect of progressive capsulotomy incision and repairs on the behavior of a normal hip within range of motion (ROM) limits with respect to the intact joint. Complete repairs …

Restoration Of Bone Material And Microstructural Properties After Long-Term Remodeling Suppression, Abigail A. Coffman

Dissertations and Theses

Anti-resorptive drugs, principally bisphosphonates (BPs), are the mainstay of osteoporosis treatment. They work by inhibiting bone resorption/remodeling, thus preventing bone loss. However, long-term suppression of bone resorption adversely affects bone tissue mechanical properties, even while conserving bone mass. Lack of remodeling leads to accumulation of fatigue-induced microdamage, altered matrix mineralization and reduction in normal bone tissue heterogeneity, causing impaired strength and fracture toughness. The most severe consequence to patients, while rare, is Atypical Femur Fractures (i.e., complete fatigue fractures of the femoral shaft). To counteract the effects of long-term remodeling suppression, a temporary break in BP treatment (a "drug holiday) …

Development Of A Biaxial Testing System For Research Of Soft Tissue Biomechanics Using Laboratory Models, Tariq Shameen

Dissertations and Theses

The rupture of the cap tissue layer of a fibroatheroma in human coronary vessels is considered the key event leading to the formation of a thrombus and myocardial infarction, resulting in more than half a million deaths in the US every year. In this study, we are interested in investigating the biomechanics of different elastomer materials that can be used as laboratory models to replicate coronary arteries’ ultimate tensile stress (0.2 - 2.08 MPa). To this end, we developed a biomechanical testing system that allows us to characterize the material properties of small samples with high accuracy and precision. We …

Work-Related Changes In The Trunk Stiffness Of Nursing Personnel, Clare Tyler

Theses and Dissertations--Biomedical Engineering

Low back pain (LBP) is a significant issue related to spinal stability and, therefore, to trunk stiffness. Due to the nature of their work, nursing personnel are exposed to potential risk factors for LBP, such as lifting and trunk flexion, which have been reported in the literature to lead to decreases in trunk stiffness. Consequently, the purpose of this study was to investigate potential occupational effects on the trunk stiffness in nursing personnel. Twenty-four nursing personnel participated in this study and completed two sessions (pre-shift and post-shift) during which two passive flexion tests (with and without an ~7.5-lb load) were …

Osteocyte Activity And Skeletal Muscle Relative Gene Expression Profiling After Short-Term Muscle Paralysis, Michelle Gelbs

Dissertations and Theses

Mechanical loading is essential for maintaining bone tissue. Reduced mechanical loading has been shown to have a negative effect on bone, and can result in the development of disuse osteoporosis. Disuse models of muscle inactivity and immobilization, like the Botox model used in this study, result in changes in the bone microarchitecture, the mechanisms behind which are not fully understood. In a previous four-week Botox disuse study, skeletally mature 20- week-old rats experienced degradation of intracortical bone, increased vascular porosity, and decreased osteocyte lacunar density in the tibiae. The focus of this study was to explicate a potential source of …

Accurate Measurement Of Healthy Joint Kinematics To Inform Diagnosis And Treatment, Vasiliki Kefala

Electronic Theses and Dissertations

The description of human motion has a primary importance in different scientific areas such as medicine, sports, physical therapy. Kinematics specifically studies pure motion without reference to the causes of motion such as forces. Understanding the kinematics of human movement is of critical importance in medicine and biology. Motion measure­ment can be used in order to to evaluate functional performance of limbs under normal and abnormal conditions. Kinematic knowledge is also important for diagnosis and surgi­cal treatment of joint disease and the design of implants to rehabilitate function. Accurate joint kinematics is essential to protect articular functionality. An alteration may …

Dislocation Mechanics Of Total Hip Arthroplasty: A Combined Experimental And Computational Analysis, Michael Scinto

Electronic Theses and Dissertations

While total hip arthroplasty is considered a successful procedure, dislocation remains a serious complication as recurrent dislocations may require additional surgeries. Knowledge on dislocation events as they occur in vivo are limited, therefore researchers rely on experimental and computational methods. A custom MATLAB script and an experimental procedure utilizing a six-degree of freedom actuator were developed to further understand how various surgical considerations affect dislocation mechanics in total hip arthroplasty. Computationally, it was determined that impingement free range of motion is limited during internal rotation in flexion and during external rotation in extension. Experimentally, our results suggest that the posterior …

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …

Improving Patient-Specific Assessments Of Regional Aortic Mechanics Via Quantitative Magnetic Resonance Imaging With Early Applications In Patients At Elevated Risk For Thoracic Aortopathy, Patrick A. Jones

Theses and Dissertations

Unstable aortic aneurysms and dissections are serious cardiovascular conditions associated with high mortality. The current gold standards for assessment of stability, however, rely on simple geometric measurements, like cross-sectional area or increased diameter between follow-up scans, and fail to incorporate information about underlying aortic mechanics. Displacement encoding with stimulated echoes (DENSE) magnetic resonance imaging (MRI) has been used previously to determine heterogeneous circumferential strain patterns in the aortas of healthy volunteers. Here, I introduce technical improvements to DENSE aortic analysis and early pilot application in patients at higher risk for the development of aortopathies. Modifications to the DENSE aortic postprocessing …