Biomedical Engineering and Bioengineering Commons^™

Theta Burst Brain Stimulation In Painful Diabetic Neuropathy Patients: Investigating Neural Mechanisms, Bhushan Thakkar

Theses and Dissertations

Chronic pain (CP) is a significant contributor to disability and disease burden globally. In 2019, approximately 50.2 million adults (20.4% of the US population) experienced chronic pain, contributing to $560-635 billion in direct medical costs. In addition, the worldwide prevalence of diabetes mellitus has reached epidemic proportions and is set to increase to 629 million by 2045. Almost 50% of patients with diabetes present with diabetic neuropathy (DN), and one in five patients with diabetes presents with painful DN (pDN) which is the most common cause of neuropathic pain (NP) in the US. Symptomatic treatment is the mainstay of management …

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 …

Combinatorial Approaches For Effective Design, Synthesis, And Optimization Of Enzyme-Based Conjugates, Jordan Scott Chapman

Graduate Theses, Dissertations, and Problem Reports (ETD)

The specificity and efficiency with which enzymes catalyze selective chemical reactions far exceeds the performance of traditional heterogeneous catalysts that are predominant in industrial applications such as conversion of commodity chemicals to value-added products, fuel cells, and petroleum refinement. Moreover, biocatalysts exhibit exceptionally high product turnover at ambient conditions with little health and environmental burden. These advantageous qualities have led to the prolific use of enzyme catalysis in pharmaceutical, detergents, and food preservation industries wherein their use has greatly reduced waste generation, Unfortunately, the full slate of benefits that enzymes can impart to a broader range of chemical processes is …

The Role Of Son In Chromatin-Mediated Gene Expression, Melissa Jordan Ward

Browse all Theses and Dissertations

Gene expression in mammalian cells requires complex nuclear choreography, and there is increasing evidence that spatiotemporal organization of chromatin and nuclear compartments plays an important role in gene expression. In this dissertation, I examined the function of SON, a splicing factor with a known role in nuclear organization, in chromatin-mediated gene expression. SON association with a transcriptionally inactive U2OS 2-6-3 reporter gene array provided a useful model to study SON’s chromatin dynamics. I demonstrated that SON associates with the inactive but not the activated array, and that SON’s RNA binding domains are not necessary for that association. Second, I discovered …

Comparison Effect On Biogas Production From Vegetable And Fruit Waste With Rumen Digesta Through Co-Digestion Process, Anika Tasnim, Muhammad Rashed Al Mamun, Md Anwar Hossen, Md Towfiqur Rahman, Md Janibul Alam Soeb

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Biogas is the best renewable energy as it can be produced from any biomass for example any plant or living organism. The purpose of this research was to produce biomethane from co-digestion of vegetable and fruit waste with rumen digesta through anaerobic digestion process. In this research, two trials of experiment were conducted. Each trial has three different sample with different mixing ratios. Raw materials used in the experiment was rumen digesta of goat and cow, potato, capsicum, cucumbers, onions, radish, cauliflower, carrot, leafy vegetables, apple, banana, and papaya. In each sample, 1200 gram of raw materials were used. Hydraulic …

Novel Microfabricated Systems To Elucidate The Role Of Anisotropic Stiffness In The Tumor Microenvironment, Jiten Narang

Theses and Dissertations

Cancer is the second leading cause of death in women and late stage (metastatic) cancers have abysmal survival rates compared to early stage regional cases (27% vs 86%). As a tumor grows, the surrounding extracellular matrix (ECM) is reorganized into a dense, collagen rich matrix. The new matrix of aligned collagen fibers provides unique mechanical cues such as anisotropic stiffness and contact guidance. Matrix turnover also constricts local vasculature and restricts delivery of key nutrients and signaling molecules to malignant cells to outside the tumor creating a chemotactic gradient from outside to inside. In this work, we developed a novel …

Dna Condensation State Regulates Nuclear Lamina Strain And Cellular Adaptation To Physiological Forces, Brooke E. Danielsson

Theses and Dissertations

The nucleus is the largest and stiffest organelle and is exposed to mechanical forces transmitted through the cytoskeleton from outside the cell, as well as from forces generation within the cell. In recent years, the nucleus has been proposed to act as a cellular mechanosensor, with changes to nuclear shape and architecture playing an important role in how the cell responds to physiological forces. Aberrant forms of the nuclear envelope protein lamin A/C, as well as epigenetic modifications to chromatin, has been shown to modify nuclear stiffness and viscosity, therefore effecting nuclear mechanics and mechanotransduction. Altered nuclear mechanics is associated …

Controlled Voltage Of Hot Snare Polypectomy Device In Electrosurgical Device, Saidi Olayinka Olalere

College of Graduate Studies: Theses & Dissertations

The study is used to understand the working procedure of the Olympus PSD-30 Electrosurgical Unit which a high-frequency alternating current is to measure the voltage and power output from the unit when used for a surgical operation to determine the extent of tissue damage. The output power and voltage were as examined with the stopwatch, then with an Arduino time based for 1, 2, and 3 seconds to understand the different modes of the cut and coagulation feedback with an RCC circuit used to mimic the human body. This shows a pattern in which the feedback power increases, and voltage …

Neural Processing Of Semantic Content In Movies, Maximilian Nentwich

Dissertations and Theses

Naturalistic stimuli, such as movies, contain interacting, multimodal and semantic features and allow for free exploration through eye movements. The full extent of neural responses to features such as motion, film cuts and eye movement behavior has not been established. The main hypothesis of this thesis is that complex multimodal and semantic stimuli in naturalistic movies engage a widespread ensemble of locations across the entire brain. To address this question I analyzed simultaneous intracranial and eyetracking data from over 6,000 electrodes across 23 patients with intractable epilepsy. Responses to fast eye movements – saccades – and film cuts are widespread …

Novel Mechanisms Of Dc And Kilohertz Electrical Stimulation, Zeinab Esmaeilpour

Dissertations and Theses

Transcranial electrical stimulation is a promising technique where a weak electrical current is applied to the scalp with the goal of modulating brain activity. Understanding the cellular mechanism of direct current (DC) and kilohertz (kHz) electrical stimulation is of broad interest in neuromodulation. More specifically, there is a large mismatch between enthusiasm for clinical applications of the method and understanding of DC and kHz novel mechanisms of action. This dissertation is centered around two main fundamental aims: 1) systematic study of the acute and long-term effects of kilohertz electrical stimulation and amplitude-modulated waveform with kHz carrier frequency using a well-established …

Impact Of Percutaneous Transluminal Intervention On Vascular Hypoxia And The Role Of Micro-Calcifications On Atherosclerotic Plaque Rupture, Andrea Corti

Dissertations and Theses

Atherosclerotic disease is initiated by cholesterol build-up beneath the endothelium, which evolves into a fibroatheroma, a lipid-rich plaque covered by a fibrous cap. Many of these plaques are considered as vulnerable, as they grow to occlude the luminal section of the artery (chronically stenotic) or become mechanically unstable with a higher chance of rupturing (rupture-prone). On one hand, chronically stenotic vulnerable plaques are symptomatic lesions that are often treated with Percutaneous Transluminal Intervention (PTI). Unfortunately, approximately 10% of PTI procedures are followed by severe Neointima Hyperplasia (NH), which causes a new occlusion and failure of the implant. A significant precursor …

Modulation Of Brain Tissue Transport And Endothelial Glycocalyx And Tight Junctions Of The Blood-Brain Barrier By Transcranial Direct Current Stimulation, Yifan Xia

Dissertations and Theses

Transcranial direct current stimulation (tDCS) is a non-invasive approach to treat a broad range of brain disorders and to enhance memory and cognition in healthy individuals. In addition to directly acting on neurons by modulating the membrane potential, inducing neuronal polarization and changing cortical excitability in the brain to achieve its therapeutic effects, prior studies found that tDCS can transiently enhance the permeability (P) of the blood-brain barrier (BBB), the interface between blood circulation and brain tissue. Brain extracellular space (ECS) is a narrow microenvironment which surrounds every cell in the central nervous system (CNS). ECS occupies ~20% of brain …

Osseointegration Of A Cementless Total Knee Arthroplasty In A Murine Model Of Glucocorticoid Induced Osteoporosis, Elexis C. Baral

Dissertations and Theses

Glucocorticoid-Induced Osteoporosis (GIOP) is the second largest cause of osteoporosis worldwide. Glucocorticoid-Induced osteoporosis is rapidly, driven principally by deficient osteoblast activity (i.e., decreased bone formation) rather than increased osteoclastic activity. Glucocorticoid-type steroids (GC) are used long-term typically for inflammatory diseases such as rheumatoid arthritis, lupus, multiple sclerosis, and other autoimmune disorders. Inflammatory arthritis often leads to joint replacement at relatively young ages. However, patients who are on GC treatment appear to have poorer outcomes for total joint arthroplasty compared to healthy patients. This is thought to be due to the anti-anabolic effects of GCs and impaired bone healing and osseous …

Computational Model Of Electroconvulsive Therapy Considering Electric Field Dependent Skin Conductivity, Gozde Unal

Dissertations and Theses

Improvements in electroconvulsive therapy (ECT) outcomes have followed refinement in device electrical output and electrode montage. The physical properties of the ECT stimulus, together with those of the patient’s head, determine the impedances measured by the device and govern current delivery to the brain and ECT outcomes. However, the precise relations among physical properties of the stimulus, patient head anatomy, and patient-specific impedance to the passage of current are long-standing questions in ECT research and practice. In this thesis, we develop a computational framework based on diverse clinical data sets. We developed anatomical MRI-derived models of transcranial electrical stimulation (tES) …

Analysis Of Eye Movements To Cartoon Faces In Videos, Kaustubh Sapru

Dissertations and Theses

Saccades are rapid eye movements that move our gaze between successive points of fixation. They are indicative of how we direct our attention and therefore play a role in memory and cognition. For static images, it is established that saccades move faster to faces compared to other objects. We hypothesize that the same is true for videos. To test this hypothesis, saccades to faces in motion pictures have been analyzed. The analysis here entails the recording of saccades to two videos followed by a statistical study of saccades going towards faces or going away from faces. What makes this study …

Development Of Cellulose-Based, Semi-Interpenetrating Network Hydrogels As Tissue-Adhesive, Thermoresponsive, Injectable Implants, Jesse Martin

Dissertations and Theses

Abstract Development of Cellulose-Based, Semi-Interpenetrating Network Hydrogels as Tissue-Adhesive, Thermoresponsive, Injectable Implants

Hydrogels are three-dimensional polymer networks with high water content and tunable mechanical properties, which have been widely investigated as replacements for soft tissues, such as the intervertebral disc (IVD). Various derivatives of the plant polysaccharide, cellulose, have been explored for use as injectable hydrogel implants. Methylcellulose (MC), which exhibits thermogelation at temperatures above 32°C, and relatively hydrophilic carboxymethyl-cellulose (CMC), are versatile cellulosic polymers that have shown promise as base materials for such applications. In prior work, functionalization with methacrylate groups allowed for the formation of stable, covalently crosslinked …

Low-Intensity Ultrasonic Neuromodulation Of The Rat Hippocampus, Duc Nguyen

Dissertations and Theses

Techniques to non-invasively modulate brain activity are important for mapping human brain circuits, and also for the treatment of a host of neurological and psychiatric disorders marked by aberrant brain activity. Though a wide range of techniques for non-invasive neuromodulation have been proposed, the conventional approaches suffer from significant limitations. Most notably, focal stimulation of deep brain regions is presently only possible with invasive optogenetic and chemogenetic approaches that require craniotomies and genetic access to the brain.

Transcranial focused ultrasound stimulation (tFUS) possesses many of the characteristics desirable from a neuromodulation approach: non-invasiveness, a spatial resolution in the order of …

Exosome- And Microrna-Based Therapeutic Approach For Tendinopathy, Angela Wang Ilaltdinov

Dissertations and Theses

Tendinopathy, characterized by degeneration and chronic inflammation, is a significant clinical burden. Current treatments focus on symptom management but do not sufficiently address its underlying pathology; however, stem cell-based approaches aimed at repairing diseased tissues may overcome this limitation. Therapeutic effects of stem cells may be due in part to paracrine actions, including some mediated by exosomes – extracellular vesicles secreted by cells that play a role in cell communication. MicroRNA (miRNA), small non-coding RNA carried by exosomes, are likely responsible for many exosome effects. Exosomes and miRNA therapies show promise in treating diseases such as cancer and arthritis, but …

Modeling Of Patient-Specific Periaortic Mechanics And Pulmonary Artery Hemodynamics Based On Phase-Contrast Magnetic Resonance Imaging Sequences., Johane H. Bracamonte

Theses and Dissertations

Inverse modeling in cardiovascular medicine is a collection of methodologies that can provide non-invasive patient-specific estimations of clinical risk factors using medical imaging as inputs. Its incorporation into clinical practice has the potential to improve diagnosis and treatment planning with low associated risks and costs.

Herein, three different phase contrast magnetic resonance imaging (MRI) modalities were implemented as input data, displacement encoding with stimulated echoes (DENSE MRI) applied, and time-resolved velocity encoding phase-contrast MRI, in 1D and 3D, applied to pulmonary artery (PA) hemodynamics.

A model to account for the effect of periaortic interactions due to static and dynamic structures …

Innovative Techniques Of Neuromodulation And Neuromodeling Based On Focal Non-Invasive Transcranial Magnetic Stimulation For Neurological Disorders, Ivan C. Carmona-Tortolero

Theses and Dissertations

This dissertation aims to develop alternative technology that improves the current range of application of transcranial magnetic stimulation (TMS), on a scale that would permit defining specific non-invasive treatments for Parkinson’s disease and other neurological disorders. This is accomplished through three specific objectives. 1) The design of a neurostimulation system that increases the focality in TMS to regions of narrow target areas and variable depths in the brain cortex. 2) The assessment of the feasibility of novel high-frequency neuromodulation techniques that would allow increasing the focality in deeper areas beyond the cortical surface. 3) The development of a computational model …

Improving The Early Detection Of Cardiovascular Toxicity Secondary To Radiotherapy For Lung Cancer Via Patient-Specific Quantitative Magnetic Resonance Imaging, Alireza Omidi

Theses and Dissertations

Purpose: To assess the cardiopulmonary-induced dose variation on the left ventricle (LV) and evaluate the spatiotemporal evolution of cardiac/aortic function following radiotherapy (RT).

Methods: 8 lung cancer patients who were scheduled to receive RT were recruited for this study. Each patient underwent one 4D-CT at baseline. MRI scans including cine GRE, T1/T2, LGE, and 4D-flow were acquired at baseline, 3-months and 6-months post-RT to evaluate the cardiac/aortic function. Finally, image registration was used to assess the cardiopulmonary-induced dose variation on the LV.

Results: Mean RT-dose was minimum during inspiration and systole (at expiration). No significant differences were found in the …

Towards The Systematic Evaluation Of Variable Modes Of Mechanical Conditioning On The Compositional, Microstructural And Mechanical Properties Of Engineered Tissue Vascular Grafts., Sarah Saunders

Theses and Dissertations

Coronary artery bypass surgery (CABG) remains one of the most common cardiac surgical procedures performed worldwide, frequently involving multiple bypasses, and commonly employing the patient’s internal mammary artery, radial artery, or saphenous vein. CABG is often not possible because native vessels were already employed in previous interventions or are diseased themselves. Synthetic vascular grafts are currently integral tools of vascular surgery and have had relative success in large-caliber applications providing substantial benefit to aortic or iliac grafting; however, small diameter (< 6 mm) arterial grafts have not yet translated into clinical effectiveness due to thrombosis and anastomotic intimal hyperplasia. ETVGs present an exciting potential alternative in vascular grafting by offering a blood vessel substitute that could exhibit all the functional characteristics of native vasculature. In addition to relieving supply limitations associated with coronary artery bypass surgery ETVGs are especially ideal for pediatric patients with congenital heart disease who require grafts that grow as they do, eliminating the need for reoccurring invasive surgeries.

Though the role of biomechanics in regulating cellular behavior promoting non-thrombogenicity, vasoactivity, and ECM synthesis and maintenance is well …

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, …

Therapeutic Approaches For Respiratory Distress Syndrome, Franck J. Kamga Gninzeko

Theses and Dissertations

Respiratory distress syndrome (RDS) is characterized by shortness of breath and low oxygen levels. RDS affects the neonatal and adult populations. In the neonatal population, RDS can be classified as NRDS (Neonatal respiratory distress syndrome), while in adults, it is known as ARDS (acute respiratory distress syndrome). This dissertation examines a therapeutic approach to NRDS and a mechanistic approach to ARDS with in vivo and in vitro models of lung injury. NRDS is characterized by a deficiency or lack of surfactant. Surfactant is an essential compound composed of phospholipids and proteins to prevent the lungs from collapsing. There are several …

Biom 1720: Introduction To Biomedical Engineering Tools (Syllabus), Stephen Strain

Biomedical Engineering Syllabi Archive

Course Description: Use of computer tools for data analysis, presentation, documentation; introduction to programming; individual and group design projects.

Biom 1702: Biomedical Engineering Visualization (Syllabus), Aaryani Sajja

Biomedical Engineering Syllabi Archive

Course Description: Using engineering drawings and computer-aided drafting packages to communicate information and solve engineering problems; emphasis on group work, project documentation, and oral presentation.

Biom 2720: Experimental Design And Analysis For Biomedical Engineering (Syllabus), Stephen Strain

Biomedical Engineering Syllabi Archive

Course Description: Application of probability, statistics, error analysis, uncertainty in design and performance of biomedical engineering experimentation; discussion and evaluation of common experimental designs for medical device development.

Biom 3110: Medical Physiology (Syllabus), Bradford D. Pendley

Biomedical Engineering Syllabi Archive

Course Description: Basic principles of human physiology and how these are applied in medicine and biomedical engineering problem and devices; physiological principles using appropriate mathematical and engineering models to construct an understanding of how the body works as an integrated system.

Biom 2720: Experimental Design And Analysis For Biomedical Engineering (Syllabus), Stephen Strain

Biomedical Engineering Syllabi Archive

Course Description: Application of probability, statistics, error analysis, uncertainty in design and performance of biomedical engineering experimentation; discussion and evaluation of common experimental designs for medical device development.