Biomedical Engineering and Bioengineering Commons^™

In Vitro Bioreactor For Mechanical Control And Characterization Of Tissue Constructs, Samuel Coeyman

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Heart failure (HF) currently affects over 6 million Americans, 50% of whom die within 5 years of their initial diagnosis. A major contributor to the onset of HF is cardiac fibrosis in the myocardium, which arises when fibroblasts (FBs) are activated in response to heightened mechanical stress from overload conditions like hypertension. Activated FBs remodel the extracellular matrix (ECM) and secrete ECM proteins including collagen. FB remodeling has been studied in the past by applying forces and/or deformations to three-dimensional, cell-seeded gels and tissue constructs in vitro. Unfortunately, previous stretching platforms have traditionally not enabled mechanical property assessment to be …

Using In Vitro, In Silico, And In-Classroom Techniques To Address The Gender Data Gap In Health Care, Kelsey Watts

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Cardiovascular diseases (CVDs) are the leading cause of death worldwide in males (XY) and females (XX). Prior to menopause, females have a relative protection against serious cardiac pathologies compared to age-matched males. This phenomenon is widely attributed to the ovarian hormone estrogen. Unfortunately, hormone replacement therapy to maintain estrogen levels in postmenopausal females has overall adverse effects, and it is not recommended for long-term use or as a preventative measure for eCVDs. A major driver of CVDs, specifically heart failure, is cardiac fibrosis: the continued buildup of scar tissue that reduces the heart’s ability to pump. There are currently no …

Development Of A Reverse Engineered, Parameterized, And Structurally Validated Computational Model To Identify Design Parameters That Influence American Football Faceguard Performance, William Ferriell

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Traumatic brain injury (TBI) continues to have the greatest incidence among athletes participating in American football. The headgear design research community has focused on developing accurate computational and experimental analysis techniques to better assess the ability of headgear technology to attenuate impacts and protect athletes from TBI. Despite efforts to innovate the headgear system, minimal progress has been made to innovate the faceguard. Although the faceguard is not the primary component of the headgear system that contributes to impact attenuation, faceguard performance metrics, such as weight, structural stiffness, and visual field occlusions, have been linked to athlete safety. To improve …

The Development And Analysis Of Methods Used To Evaluate American Football Facemasks, Alexander Bina

All Dissertations

The motivation for this Ph.D. dissertation is to provide football equipment managers, coaches, parents, athletes, and relevant industry personnel with an understanding of the implication a chosen football facemask design will have on the safety of the athlete. As athletes have increased their capacity for speed, size, and strength, so too has the head injury risk increased in American football. To align with the increase in head impact injury in American football, the protective head impact community must expand its capacity to evaluate protective equipment systems. This dissertation focuses specifically on one helmet system component: the football facemask. This dissertation …

Multi-Scale Vertebral-Kinematics Based Simulation Pipeline Of The Human Spine With Application To Spine Tissues Analysis, Mohd Jaradat

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This study developed an analytical tool for understanding spine tissues’ behavior in response to vertebral kinematics and spine pathology over a range of body postures. It proposed a novel pipeline of computational models based on predicting individual vertebral kinematics from measurable body-level motions, using musculoskeletal dynamics simulations to drive the vertebrae in corresponding spine FEMs.

A reformulated elastic surface node (ESN) lumbar model was developed for use in MSD simulations. The ESN model modifies the lumbar spine within an existing MSD model by removing non-physiological kinematic constraints and including elastic IVD behavior. The model was scaled using subject-specific anthropometrics and …

Characterization Of Thermal Gelation Properties In Bioresorbable Thermally Activated Hydrogel Polymers For Hernia Surgery Applications, Alexander Mayfield

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Hydrogel adhesives are a new class of materials with excellent biocompatibility, which makes them very attractive for biomaterial applications. It has been previously shown that Tetronic T1107, a four-arm poly (propylene oxide)-poly (ethylene oxide) (PPO-PEO) block copolymer, is useful as a chemical crosslinking thermo-responsive hydrogel for bioadhesive applications. The end groups of this polymer are modified with acrylate and N-hydroxysuccinimide (NHS) functional groups. The acrylate end group gives the polymer cohesive properties with long-range chemical crosslinking using dithiothreitol (DTT), while the NHS end group gives the polymer adhesive properties through bonding with amines found in organic tissue. It was found …

Variations In Surgeon-Applied Loads During Passive Range Of Motion Following Total Knee Replacement With Relevance To Computational Modeling, Cj Bakle Ii

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Total knee replacement (TKR) is generally considered a successful treatment for musculoskeletal disorders of the knee. However, as many as 20% of patients report some dissatisfaction in their physical function after TKR. And approximately 50% of early revisions needed to address conditions related to component alignment and soft tissue tension to stabilize the knee. During TKR, surgeons manually perform passive range of motion (ROM) assessments to gain feedback perceived as tension in ligaments and other soft tissues. Such assessments are highly subjective and rely on the surgeon's perception of soft tissue tension rather than quantitative objective means. The variability in …

Design Of A Four Channel Pulsatile Perfusion Bioreactor For Ex-Vivo Study Of Vascular Grafts, Thomas M. Fair

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Cardiovascular diseases are the leading cause of death in the United States. Atherosclerosis in peripheral arteries is a major contributing factor. Autologous saphenous vein grafts are the most common bypass grafts for treating peripheral artery diseases. A quarter of these grafts fail within a year, and around half have failed within 10 years of the initial surgery. Graft failure is attributed to the development of intimal hyperplasia indicated by the migration and proliferation of vascular smooth muscle cells, fibroblasts, and the deposition of extracellular proteins.

Increases in flow, pressure, the pulse frequency, and the differential of pressure that model an …