Biomedical Engineering and Bioengineering Commons^™

Environment And Response Of 3d-Encapsulated Mesenchymal Stem Cells To Mechanical Loading, Augustus Greenwood

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis explores the micromechanical environment induced when cyclically compressing hydrogels via finite element modeling and experimentally on the impact of loading on mesenchymal stem cells (MSCs) when encapsulated withing 3D hydrogel matrices. Degenerative joint diseases, characterized by cartilage degradation, present significant challenges due to cartilage's limited self-repair capacity. Innovative approaches, including stem cell-based therapies and engineered biomaterials, have emerged as promising strategies for cartilage repair and regeneration. This work specifically investigates the calibration of a bioreactor, the uniformity of load response across the hydrogel constructs via finite element modeling (FEM), and the stress response of MSCs subjected to various …

Quantification Of Age-Related Changes In The Structure And Mechanical Function Of Skin With Multiscale Imaging, Alan E. Woessner, Nathan J. Witt, Jake D. Jones, Edward A. Sander, Kyle P. Quinn

Biomedical Engineering Faculty Publications and Presentations

The mechanical properties of skin change during aging but the relationships between structure and mechanical function remain poorly understood. Previous work has shown that young skin exhibits a substantial decrease in tissue volume, a large macro-scale Poisson’s ratio, and an increase in micro-scale collagen fiber alignment during mechanical stretch. In this study, label-free multiphoton microscopy was used to quantify how the microstructure and fiber kinematics of aged mouse skin affect its mechanical function. In an unloaded state, aged skin was found to have less collagen alignment and more non-enzymatic collagen fiber crosslinks. Skin samples were then loaded in uniaxial tension …

Fibrous Finite Element Modeling Of The Optic Nerve Head Region, Mohammad R. Islam, Fengting Ji, Manik Bansal, Yi Hua, Ian A. Sigal

Mechanical Engineering Faculty Publications

The optic nerve head (ONH) region at the posterior pole of the eye is supported by a fibrous structure of collagen fiber bundles. Discerning how the fibrous structure determines the region biomechanics is crucial to understand normal physiology, and the roles of biomechanics on vision loss. The fiber bundles within the ONH structure exhibit complex three-dimensional (3D) organization and continuity across the various tissue components. Computational models of the ONH, however, usually represent collagen fibers in a homogenized fashion without accounting for their continuity across tissues, fibers interacting with each other and other fiber-specific effects in a fibrous structure. We …

The Effects Of Bilateral Stimulation On Motor Learning, Shania Rehmudin

Dissertations and Theses

Motor learning is a set of complex processes aimed at learning and refining new skills by practicing them. There are three proposed stages of motor learning: cognitive, associative, and autonomous. While all stages are crucial, research suggests that the cognitive stage holds particular significance, laying the foundational groundwork for effective skill acquisition. Although research has explored many innovative ways to facilitate motor memory, to our knowledge, none has explored the optimization of motor skill learning through manipulating the focus of attention using bilateral stimulation. Therefore, this study explored the effects of bilateral stimulation on squat skill acquisition. Nineteen (19) subjects, …

Muscle Activation And Coordinated Movements Of Infant Rolling, Danielle N. Siegel, Safeer F. Siddicky, Wyatt D. Davis, Erin M. Mannen

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Rolling is a critical step of infant development, encouraging muscle coordination and enabling independent exploration. Understanding muscle activity during infant rolling movements on a flat surface is necessary to more fully characterize how the rolling milestone is achieved. The purpose of this study was to determine infants’ muscle activation throughout roll initiation for six previously established coordinated movements. Thirty-eight healthy infants (age: 6.5 ± 0.7 months; 23M/15F) were enrolled in this IRB-approved in-vivo biomechanics study. Surface electromyography sensors recorded muscle utilization from the erector spinae, abdominal muscles, quadriceps, and hamstrings while infants rolled. Each rolling movement was categorized as one …

Custom Mobility Aid - Exoskeleton, Jenna Rentsch, Mackenzie Yu, Perry Antalek, Joseph Wisniewski

Williams Honors College, Honors Research Projects

Injuries to the spinal cord can cause major mobility deficits, paralysis, and even death. Our client is an adult male who has suffered fractures to the C4 and C5 vertebrae resulting in partial nerve damage and loss of mobility in the lower extremities, primarily on the left side. He complains of significant loss of function and frequent falls due to an inability to fully pick-up his left foot and hold his hip in flexion during swing phase of gait. He describes his walking as a "stuttered walk" and frequently complains that his left foot drags and drops during steps. The …

Electroencephalography And Biomechanics Of The Basketball Throw, Phong Ky Phan

Theses and Dissertations

According to various studies, compared with novice athletes, experts exhibit superior integration of perceptual, cognitive, and motor skills. This superior ability has been associated with the focused and efficient organization of task-related neural networks. Specifically, skilled individuals demonstrate a spatially localized or relatively lower response in brain activity, characterized as ‘neural efficiency’, when performing within their domain of expertise. Previous works also suggested that elite basketball players can predict successful free throws more rapidly and accurately based on cues from body kinematics. These traits are the result of a prolonged training of specific motor skills and focused excitability of the …

Deep Learning And Generative Ai Approaches For Automated Diagnosis And Personalized Treatment: Bridging Machine Learning, Medicine, And Biomechanics In Predicting Tissue Mechanics And Biomaterial Properties., Yasin Shokrollahi

Theses and Dissertations

Machine learning, particularly deep neural networks, has demonstrated significant potential in predicting high-dimensional tasks across various domains. This work encompasses a detailed review of Generative AI in healthcare and three studies integrating machine learning with finite element analysis for predicting biomechanical behaviors and properties. Initially, we provide a comprehensive overview of Generative AI applications in healthcare, focusing on Transformers and Denoising Diffusion models and suggesting potential research avenues to address existing challenges.

Subsequently, we addressed soccer-related ocular injuries by combining finite element analysis and machine learning to predict retinal mechanics following a soccer ball hit rapidly. The prediction errors are …

Digital Twins Of The Living Knee: From Measurements To Model, Thor Erik Andreassen

Electronic Theses and Dissertations

Modern medicine has dramatically improved the lives of many. In orthopaedics, robotic surgery has given clinicians superior accuracy when performing interventions over conventional methods. Nevertheless, while these and many other methods are available to ensure treatments are performed successfully, far fewer methods exist to predict the proper treatment option for a given person. Clinicians are forced to categorize individuals, choosing the best treatment on “average.” However, many individuals differ significantly from the “average” person, for which many of these treatments are designed. Going forward, a method of testing, evaluating, and predicting different treatment options' short- and long-term effects on an …

Computational Methodology For Generating Patient-Specific Soft Tissue Representations, Ahilan Anantha Krishnan

Electronic Theses and Dissertations

This dissertation focused on modeling specimen-specific soft tissue structures in the context of joint replacement surgery. The research addressed four key aspects. The first study involved developing a workflow for creating finite element models of the hip capsule to replicate its torque-rotational response. Experimental data from ten cadaveric hips were used to calibrate the models, resulting in improved accuracy and relevance for surgical planning and implant design. The second study tackled the challenge of expediting the calibration of mechanical properties of the hip capsule to match patient-specific laxities. A statistical shape function model was proposed to generate patient-specific finite element …

Editorial: Intervertebral Disc Degeneration And Osteoarthritis: Mechanisms Of Disease And Functional Repair., Graciosa Q Teixeira, Jana Riegger, Raquel M Gonçalves, Makarand V. Risbud

Department of Orthopaedic Surgery Faculty Papers

No abstract provided.

Patient Movement Monitoring Based On Imu And Deep Learning, Mohsen Sharifi Renani

Electronic Theses and Dissertations

Osteoarthritis (OA) is the leading cause of disability among the aging population in the United States and is frequently treated by replacing deteriorated joints with metal and plastic components. Developing better quantitative measures of movement quality to track patients longitudinally in their own homes would enable personalized treatment plans and hasten the advancement of promising new interventions. Wearable sensors and machine learning used to quantify patient movement could revolutionize the diagnosis and treatment of movement disorders. The purpose of this dissertation was to overcome technical challenges associated with the use of wearable sensors, specifically Inertial Measurement Units (IMUs), as a …

Balance Assessment Using A Smartwatch Inertial Measurement Unit With Principal Component Analysis For Anatomical Calibration, Benjamin M. Presley, Jeffrey C. Sklar, Scott J. Hazelwood, Britta Berg-Johansen, Stephen M. Klisch

Biomedical Engineering

Balance assessment, or posturography, tracks and prevents health complications for a variety of groups with balance impairment, including the elderly population and patients with traumatic brain injury. Wearables can revolutionize state-of-the-art posturography methods, which have recently shifted focus to clinical validation of strictly positioned inertial measurement units (IMUs) as replacements for force-plate systems. Yet, modern anatomical calibration (i.e., sensor-to-segment alignment) methods have not been utilized in inertial-based posturography studies. Functional calibration methods can replace the need for strict placement of inertial measurement units, which may be tedious or confusing for certain users. In this study, balance-related metrics from a smartwatch …

Mitral Valve Imaging And Biomechanics: A Workflow Towards Computational Modeling And Validation, Sam Stephens

Graduate Theses and Dissertations

The mitral valve serves a critical role in healthy cardiac function by ensuring the unidirectional flow of oxygenated blood from the left atrium into the left ventricle. It experiences the highest pressures found within the heart and its closure is the result of a complex interaction of several different structures that, furthermore, are unique to each individual. Despite the valve’s vital role however, the specific function of these constituent structures is not fully understood. This, confounded by its asymmetric, personalized nature, make surgical interventions for the mitral valve far less effective than for its neighboring aortic valve. Efforts to overcome …

Integrating Shear Flow And Trypsin Treatment To Assess Cell Adhesion Strength, Antra Patel, Bhavana Bhavanam, Trevor Keenan, Venkat Maruthamuthu

Mechanical & Aerospace Engineering Faculty Publications

Cell adhesion is of fundamental importance in cell and tissue organization and for designing cell-laden constructs for tissue engineering. Prior methods to assess cell adhesion strength for strongly adherent cells using hydrodynamic shear flow either involved the use of specialized flow devices to generate high shear stress or used simpler implementations like larger height parallel plate chambers that enable multihour cell culture but generate low wall shear stress and are, hence, more applicable for weakly adherent cells. Here, we propose a shear flow assay for adhesion strength assessment of strongly adherent cells that employs off-the-shelf parallel plate chambers for shear …

Quantifying Fibronectin Mechanical Properties Using Antibody-Mediated Optical Tweezing (Amot), Caleb Dalton

Theses and Dissertations

Despite decades of investigations into fibronectin (FN) fibrillogenesis, fibril mechanics remain unclear. One of the most important roles for FN fibrils is in the arena of cellular mechanotransduction. Numerous studies have demonstrated that cells sense and respond to the mechanical properties of their surroundings; since FN fibrils are a major constituent of the ECM that links cells to their surroundings, mechanotransduction cannot be fully understood without understanding the mechanical properties of FN fibrils. In this proposal, a novel biomechanical assay is developed to probe isolated FN fibrils and quantify their response to specific loading conditions. This will be accomplished by …

Making Sense Of Big (Kinematic) Data: A Comprehensive Analysis Of Movement Parameters In A Diverse Population, Naomi Wilma Nunis

University of the Pacific Theses and Dissertations

OBJECTIVE

The purpose of this study was to determine how kinematic, big data can be evaluated using computational, comprehensive analysis of movement parameters in a diverse population.

METHODS

Retrospective data was collected, cleaned, and reviewed for further analysis of biomechanical movement in an active population using 3D collinear resistance loads. The active sample of the population involved in the study ranged from age 7 to 82 years old and respectively identified as active in 13 different sports. Moreover, a series of exercises were conducted by each participant across multiple sessions. Exercises were measured and recorded based on 6 distinct biometric …

Low Intensity Vibration Protects The Weight Bearing Skeleton And Suppresses Fracture Incidence In Boys With Duchenne Muscular Dystrophy, Maria Luisa Bianchi, Silvia Vai, Giovanni Baranello, Francesca Broggi, Stefan Judex, Thomas N. Hangartner, Clinton Rubin

Biomedical, Industrial & Human Factors Engineering Faculty Publications

The ability of low intensity vibration (LIV) to combat skeletal decline in Duchenne Muscular Dystrophy (DMD) was evaluated in a randomized controlled trial. Twenty DMD boys were enrolled, all ambulant and treated with glucocorticoids (mean age 7.6, height adjusted Z scores [HAZ] of hip bone mineral density [BMD] −2.3). Ten DMD boys were assigned to stand for 10 min/d on an active LIV platform (0.4 g at 30 Hz), while 10 stood on a placebo device. Baseline and 14 month bone mineral content (BMC) and BMD of spine, hip, and total body were measured with DXA, and trabecular bone density …

Smart Spine Tape: Active Wearable Posture Monitoring For Prevention Of Low Back Pain And Injury, Samuel J. Borda

Master's Theses

Back pain and injury are a global health issue and are a leading cause of work and activity absence. Prevention would not only save those affected from the burden of pain and discomfort, but would also save people from loss of over 290 million workdays annually and save the healthcare system billions of dollars in expenses per year. Successful research and development of a wearable technology capable of comprehensively monitoring spinal postures that are leading causes of back pain and injury can result in prevention of mild to severe back pain and injury for high-risk people. To accomplish this, the …

Validation Of Experimental And Finite Element Biomechanical Evaluation Of Human Cadaveric Mandibles, Shirish M. Ingawale, Deepak G. Krishnan, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Background: Biomechanical analysis of human mandible is important not only to understand mechanical behavior and structural properties, but also to diagnose and develop treatment options for mandibular disorders. Therefore, the objective of this research was to generate analytical and experimental data on mandibles, construct custom 3D models, and compare the analytically derived maximum strains with strain gage data in five areas of interest for each mandible. Methods: We investigated the surface strains in the cadaveric human mandibles under different configurations of cyclic compressive loads in an experimental setting and compared these experimental strain data with results derived from computational finite …

An Improved Polynomial Chaos Expansion Based Response Surface Method And Its Applications On Frame And Spring Engineering Based Structures, Mhd A. Hafez

ETD Archive

In engineering fields, computational models provide a tool that can simulate a real world response and enhance our understanding of physical phenomenas. However, such models are often computationally expensive with multiple sources of uncertainty related to the model’s input/assumptions. For example, the literature indicates that ligament’s material properties and its insertion site locations have a significant effect on the performance of knee joint models, which makes addressing uncertainty related to them a crucial step to make the computational model more representative of reality. However, previous sensitivity studies were limited due to the computational expense of the models. The high computational …

Recent Advances In Bone Research 2022 Edition, Jean-Philippe Berteau, Laurent Pujo-Menjouet

Publications and Research

More and more scientific and engineering applications in bone research make pivotal advances in treating patients with orthopedics issues. Hence, bone research in the 21st century combines, inter alia, biology, chemistry, mathematics, and mechanics with complementary characteristics that help a holistic approach to bone-related pathologies. Nowadays, it is hard to connect new evidence when jargoning and money remain two significant obstacles to sharing knowledge. “Recent Advances In Bone Research” is a free book – no money involved at any stage - that combines the most recent efforts in bone research from several experts with different backgrounds, every expert seeks to …

Insect Antennae As Bioinspirational Superstrong Fiber-Based Microfluidics, Griffin J. Donley

All Theses

Nature is frequently turned to for inspiration for the creation of new materials. Insect antennae are hollow, blood-filled fibers with complex shape, and are cantilevered at the head. The antenna is muscle-free, but the insect can controllably flex, twist, and maneuver it laterally. To explain this behavior, a comparative study of structural and tensile properties of the antennae of Periplaneta americana (American cockroach), Manduca sexta (Carolina hawkmoth), and Vanessa cardui (painted lady butterfly) was performed. These antennae demonstrate a range of distinguishable tensile properties, responding either as brittle fibers (Manduca sexta) or strain-adaptive fibers that stiffen when stretched (Vanessa cardui …

Development And Application Of 3d Kinematic Methodologies For Biomechanical Modelling In Adaptive Sports And Rehabilitation, Anne Marie Severyn

All Dissertations

Biomechanical analysis is widely used to assess human movement sciences, specifically using three-dimensional motion capture modelling. There are unprecedented opportunities to increase quantitative knowledge of rehabilitation and recreation for disadvantaged population groups. Specifically, 3D models and movement profiles for human gait analysis were generated with emphasis on post-stroke patients, with direct model translation to analyze equivalent measurements while horseback riding in use of the alternative form of rehabilitation, equine assisted activities and therapies (EAAT) or hippotherapy (HPOT). Significant improvements in gait symmetry and velocity were found within an inpatient rehabilitation setting for patients following a stroke, and the developed movement …

Baseball Pitching Arm Three-Dimensional Inertial Parameter Calculations From Body Composition Imaging And A Novel Overweight Measure For Youth Pitching Arm Kinetics, Dalton J. Jennings, Scott K. Reaves, Jeffrey Sklar, Colin Brown, John Mcphee, Scott Hazelwood, Stephen M. Klisch

Biomedical Engineering

Many baseball pitching studies have used inverse dynamics to assess throwing arm kinetics as high and repetitive kinetics are thought to be linked to pitching injuries. However, prior studies have not used participant-specific body segment inertial parameters (BSIPs), which are thought to improve analysis of high-acceleration motions and overweight participants. This study's objectives were to (1) calculate participant-specific BSIPs using dual energy X-ray absorptiometry (DXA) measures, (2) compare inverse dynamic calculations of kinetics determined by DXA-calculated BSIPs (full DXA-driven inverse dynamics) against kinetics using the standard inverse dynamics approach with scaled BSIPs (scaled inverse dynamics), and (3) examine associations between …

Biomechanical Analysis Of Athletes Sprinting With Varying Degrees Of Resistance, Michaela Ott

Honors Program: Senior Projects (Public)

Utilizing resistance methods for sprinters is a common approach to their training. In this study, six athletes from the University of Nebraska-Lincoln Women’s Track and Field Team ran a series of sprints using a resistance machine to collect data regarding the change in power output, stride length, level of trunk tilt with respect to the ground, and acceleration throughout a distance of ten meters when different amounts of resistant forces were applied to the athlete. It was hypothesized that as resistance increased, power output would increase, stride length would decrease, the runners would become more horizontal resulting in a larger …

Youth Pitching Kinematics: Associations With Body Overweight Parameters, Christina K. Fong

Master's Theses

The objective of this study was to investigate associations between injury-related kinematic parameters and overweight measures for youth baseball pitchers. The injury-related kinematic parameters considered were measurements 1) at foot contact: stride length, front foot position, shoulder external rotation, shoulder abduction, and elbow flexion; 2) between FC and ball release: peak knee extension; and 3) at BR: shoulder abduction. Data from three separate collection sites examined pitching mechanics of 18 10- to 11-year-old pitchers, 11 14- to 16-year-old pitchers, and 104 16- to 18-year-old pitchers Linear regression analyses were performed to determine significant correlations between kinematic parameters and body mass …

Multi-Task Neuromuscular Generalization And Changes Through The Lifespan, Hannah Delaney Carey

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mobility in everyday life requires executing and shifting between a broad assortment of functional tasks and resisting disturbances that could cause falls. Though the importance of successfully performing a variety of functional tasks is recognized and incorporated in clinical assessments (e.g., the Timed-Up-and-Go Test, Berg Balance Scale), little is understood about the underlying neuromuscular control required, or how it changes with age. The neuromuscular control for functional tasks such as walking is typically studied in isolation, or with variations on the same task. Characterizing the coordination required to produce and shift between a wider variety of tasks and resist external …

Characterizing Locomotor Disturbance Perception In Young Adults, Daniel James Liss

Graduate Theses, Dissertations, and Problem Reports (ETD)

Falls during walking are a leading cause of injuries across aging. Many of these falls are due to slips and trips. The ability to perceive disturbances to ongoing motion may play an important role in the control of walking balance. However, disturbance perception has been investigated in standing balance, but its role in walking balance due to slip- and trip-like disturbances remains largely unknown. Characterizing locomotor disturbance perception in young adults may lead to a more comprehensive understanding of sensorimotor walking balance control.

This work defined locomotor disturbance perception in response to slip and trip-like disturbances in young adults. We …

Effect Of Viscoelasticity On Cellular Morphology And Activity, Thomas J. Petet Jr

Theses and Dissertations

It has been well established that there is a link between substrate stiffness and cellular activities such as proliferation, migration, and differentiation. Less characterized is the link between the time-dependent viscosity of a substrate with those cellular activities. To explore this, PDMS substrates were created with predictably tunable stiffness and viscosity parameters. A simulated model was also developed in parallel to explore the potential effects of viscosity in a computationally predictive way. It was found that the inclusion of viscosity caused a major paradigm shift to a non-zero substrate equilibrium that was sensitive to increases in the substrate stiffness. Finally, …