Engineering Commons^™

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 …

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, …

Visual Oscillation Effects On Dynamic Balance Control In People With Multiple Sclerosis, Lara I. Riem, Scott A. Beardsley, Ahmed Z. Obeidat, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Background: People with multiple sclerosis (PwMS) have balance deficits while ambulating through environments that contain moving objects or visual manipulations to perceived self-motion. However, their ability to parse object from self-movement has not been explored. The purpose of this research was to examine the effect of medial-lateral oscillations of the visual field and of objects within the scene on gait in PwMS and healthy age-matched controls using virtual reality (VR).

Methods: Fourteen PwMS (mean age 49 ± 11 years) and eleven healthy controls (mean age: 53 ± 12 years) participated in this study. Dynamic balance control was assessed while participants …

A Highly Conductive, Flexible, And 3d-Printable Carbon Nanotube-Elastomer Ink For Additive Bio-Manufacturing, Andy Shar, Phillip Glass, Daeha Joung Ph.D.

UROP Posters

The synthesis of a highly conductive, flexible, 3D-printable, and biocompatible ink has been of great interest in the field of bio-based additive manufacturing. Various applications include ultra-sensitive, microscale tactile sensors, patient-customizable scaffolds for cardiac and nerve tissue regeneration, and flexible electrocardiogram (ECG) electrodes. Here, a novel elastomeric carbon nanocomposite is presented consisting of amino-functionalized carbon nanotubes (CNT-NH₂) homogenously dispersed in a one-part room-temperature vulcanizing (RTV) silicone matrix. The use of acetone as a swelling solvent aids in electrical percolation through the elastomer matrix. CNT-NH₂ ratios can be tuned to fit various needs; higher tensile strength is favored …

Immunomodulatory Functions Of Human Mesenchymal Stromal Cells Are Enhanced When Cultured On Hep/Col Multilayers Supplemented With Interferon-Gamma, Mahsa Letter-Mahsa Haseli, David A. Castilla-Casadiego, Luis Carlos Pinzon-Herrera, Alexander Hillsley, Katherine A. Miranda-Munoz, Srikanth Sivaraman, Adrianne M. Rosales, Raj R. Rao, Jorge Almodovar

Chemical Engineering Faculty Publications and Presentations

Human mesenchymal stromal cells (hMSCs) are multipotent cells that have been proposed for cell therapies due to their immunosuppressive capacity that can be enhanced in the presence of interferon-gamma (IFN-γ). In this study, multilayers of heparin (HEP) and collagen (COL) (HEP/COL) were used as a bioactive surface to enhance the immunomodulatory activity of hMSCs using soluble IFN-γ. Multilayers were formed, via layer-by-layer assembly, varying the final layer between COL and HEP and supplemented with IFN-γ in the culture medium. We evaluated the viability, adhesion, real-time growth, differentiation, and immunomodulatory activity of hMSCs on (HEP/COL) multilayers. HMSCs viability, adhesion, and growth …

Minimally Invasive In Vivo Endoscopic Monitoring Of Dextran Sulfate Sodium-Induced Murine Colitis, Elizabeth A. Bullard, Ariel I. Mundo, Shelby N. Bess, Kathryn Miller Priest, Timothy J. Muldoon

Biomedical Engineering Faculty Publications and Presentations

Ulcerative colitis (UC) is a gastrointestinal, autoimmune disease that causes ulceration and inflammation of the colon with an incidence of 10 out of every 100,000 people in North America and Western Europe. Though the specific cause is unknown, several studies have demonstrated that inflammatory cells as well as environmental variables, genetics, and lifestyle behaviors can play a role in the long-term inflammatory response. Researchers have commonly used immunohistochemistry, western blotting and gene sequencing to establish the cellular processes behind UC relapse and remission. However, because these destructive methods necessitate the removal of a sample, they can only be used on …

Raman Spectroscopy Reveals Phenotype Switches In Breast Cancer Metastasis, Santosh Kumar Paidi, Joel Rodriguez Troncoso, Mason G. Harper, Zhenhui Liu, Khue G. Nguyen, Sruthi Ravindranathan, Lisa Rebello, David E. Lee, Jesse D. Ivers, David A. Zaharoff, Narasimhan Rajaram, Ishan Barman

Biomedical Engineering Faculty Publications and Presentations

The accurate analytical characterization of metastatic phenotype at primary tumor diagnosis and its evolution with time are critical for controlling metastatic progression of cancer. Here, we report a label-free optical strategy using Raman spectroscopy and machine learning to identify distinct metastatic phenotypes observed in tumors formed by isogenic murine breast cancer cell lines of progressively increasing metastatic propensities. Methods: We employed the 4T1 isogenic panel of murine breast cancer cells to grow tumors of varying metastatic potential and acquired label-free spectra using a fiber probe-based portable Raman spectroscopy system. We used MCR-ALS and random forests classifiers to identify putative spectral …

Nano-, Encapsulated Manganese Oxide (Nemo) Particles For Mri Enhancement In Microfluidic Tumor Models, Kasey Alexis Freshwater

Graduate Theses, Dissertations, and Problem Reports (ETD)

Breast cancer is among the deadliest cancers in women, with approximately 2.3 million new cases and 685,000 deaths reported globally in 2020 alone. Magnetic Resonance Imaging (MRI) is commonly used to diagnose, stage, and develop treatment plans for patients predisposed to breast cancer. However, current MRI-based screening of breast cancer has high false-positive rates up to 25%, leading to unnecessary invasive follow-up screening and testing. The gold-standard intravenous gadolinium (Gd)-based contrast agents (GBCAs) account for false-positive rates because they are always “ON”, providing a constant MRI signal that highlights both benign and malignant tumors. The work detailed in this thesis …

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 …

Tumor-Targeted Ph-Sensitive Manganese Oxide Nanoparticle For Enhanced Detection Of Breast Cancer Using Mri, Celia Martinez De La Torre

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the United States, approximately 287,850 new cases of invasive breast cancer will be diagnosed, and over 43,000 women will die because of it in 2022. Currently, mammography is the gold standard for breast cancer surveillance. Although this detection technique is relatively cheap and fast, it misses about 1 in 5 breast cancers in younger women with dense breast tissue, causing a delay in treatment. Compared to mammography, magnetic resonance imaging (MRI) has superior soft-tissue contrast that elucidates structural differences within soft tissue to detect more breast cancers. However, MRI still misses

NEMO particles were produced by synthesizing manganese oxide …

Contact Simulation For Evaluating Patient Specific Surgical Guide Stability, Vincent Nierste

Electronic Theses and Dissertations

This study proposes a novel computational method to quantify guide stability for Patient Specific Instrumentation (PSI) guides. A finite element contact model was used to analyze the final position of PSI guides on a femur across a range of loading parameters representing forces applied by a surgeon during operative use. Separate segmentation methods were used for the guide and bone geometry to represent differences between segmentation and actual patient geometry. The region of loading parameters over which the guide exhibited a consistent final position was measured and reported as Guide Stability Score. The model was verified using cadaver specimens for …

An Investigation Into The Plate Fixation For Periprosthetic Femoral Fractures, Xiang Chen

Electronic Theses and Dissertations

Periprosthetic femoral fractures are the third most reason for reoperation after the total hip arthroplasty with an incident rate of approximately 6%. The Vancouver type B periprosthetic femoral fractures account for over 70% of all cases, while the sub-type B1 fracture (when the total hip stem is stable) has remained a clinical challenge due to incidences of severe complications after the standard plate-screw fixation. To seek biomechanically sound fixations for the Vancouver type B1 fracture, this dissertation developed a combined modeling and testing framework to investigate the efficacy of fixation for a Vancouver type B1 fracture using different construct lengths …

Atmospheric Air Plasma Streamers Deliver Nanosecond Pulses For Focused Electroporation, Shu Xiao, Carol Zhou, Eric Appia, Shirshak Dhali

Bioelectrics Publications

Background: For electrotherapies that involve electrodes and high-intensity electric fields, such as in tissue ablation, we report a method of pulse delivery that can focus the electric field away from the electrodes, as demonstrated in vitro.

Materials and Methods: To electroporate cells in a monolayer seeded in a 35 mm culture dish, two atmospheric-pressure plasma channels generated by two thin, copper foil electrodes above the surface of the solution provided the current and established the electric field.

Results: Depending on the pulse duration, the plasma channels were observed as corona (100 ns), streamer (300 ns), and mixture of streamer …

Synthesis And Characterization Of Glycosaminoglycan Mimetic Variants For Cartilage Tissue Engineering Applications, Richard David Vincent Jr.

Dissertations

No abstract provided.

Rapid Ac Electrokinetic Micromixer With Electrically Conductive Sidewalls, Fang Yang, Wei Zhao, Cuifang Kuang, Guiren Wang

Faculty Publications

We report a quasi T-channel electrokinetics-based micromixer with electrically conductive sidewalls, where the electric field is in the transverse direction of the flow and parallel to the conductivity gradient at the interface between two fluids to be mixed. Mixing results are first compared with another widely studied micromixer configuration, where electrodes are located at the inlet and outlet of the channel with electric field parallel to bulk flow direction but orthogonal to the conductivity gradient at the interface between the two fluids to be mixed. Faster mixing is achieved in the micromixer with conductive sidewalls. Effects of Re numbers, applied …

Antimicrobial Susceptibility Of P. Aeruginosa Clinical Isolates, Tian Gao

Theses - ALL

Long-term infection caused by P. aeruginosa poses a major threat to personal and public health, and causes billions of dollars in medical expenses. To develop more effective controls, it is important to accurately evaluate antibiotic susceptibility of clinical isolates and understand how susceptibility changes during the course of infection. Conventional drug susceptibility tests using nutrient-rich media have been questioned regarding their relevance due to the difference between the model in vivo test conditions and the environment in the patients. Here, we report that 27 clinical strains of P. aeruginosa isolated from cystic fibrosis patients showed higher drug resistance in Artificial …

Substrate Delivery Of Embedded Liposomes, Srivatsan Kidambi, Stephen L. Hayward

Department of Chemical and Biomolecular Engineering: Faculty Publications

This invention relates to compositions useful for localized and sustained release of therapeutic agents, and more particularly to functionalized liposomes embedded in a poly electrolyte multilayer. Methods of preparing the compositions, methods of treating diseases, devices, and pharmaceutical compositions comprising the compositions are also provided.

Convergence Properties Of Solutions Of A Length-Structured Density-Dependent Model For Fish, Geigh Zollicoffer

Rose-Hulman Undergraduate Mathematics Journal

We numerically study solutions to a length-structured matrix model for fish populations in which the probability that a fish grows into the next length class is a decreasing nonlinear function of the total biomass of the population. We make conjectures about the convergence properties of solutions to this equation, and give numerical simulations which support these conjectures. We also study the distribution of biomass in the different age classes as a function of the total biomass.

The Development Of A Novel Blood-Brain Barrier, Organ-On-A-Chip System And The Identification Of Erythrocytes As A Key Contributor To Age-Associated Neurological Decline, Payam Amiri

KGI Theses and Dissertations

Advancements in modern medicine have greatly extended human life expectancy. However, with the onset of age-associated conditions such as Alzheimer’s disease, autoimmune disorders, and certain cancers, healthy aging is becoming an increasingly pressing issue. Blood exchanges between young and old partners demonstrate old blood can cause detrimental effect to the young animal, notably on the brain tissue. However, the complexity of blood makes it difficult to identify what role the individual factors play in the aggregate observed effect. This dissertation seeks to explore the potential effects of erythrocytes on the brain as we age. Erythrocyte morphology and rigidity changes as …

Detecting Viral Particles In Vitro Using Photoacoustic Flow Cytometry, Anie-Pier Samson

Electronic Theses and Dissertations

The Covid-19 pandemic is a powerful example of just how damaging the rapid spread of an unknown virus can be. Viruses have the ability to spread rapidly amongst individuals if not treated and controlled. The first key step towards treatment is the timely and specific diagnosis of the virus causing the infection. An innovative method for the rapid detection of viral particles in solution consists of tagging the viral particles paired with using photoacoustic flow cytometry to irradiate the particles and get a signal. The high affinity of Streptavidin for Biotin can be used to bind Streptavidin-coated microspheres to biotinylated …

Real-Time Monitoring Of Cell Death Progress Using Capacitance Spectroscopy, Suyang Wu

Electronic Theses and Dissertations

Biologics, including the monoclonal antibody (mAb), has experienced rapid development in the last decade. However, the price of biologics is often prohibitively high because of the low process efficiency. Delaying the inevitable cell death improves the productivity of upstream bioprocessing, whose success relies on monitoring the cell death onset that indicates the timing for preventive actions.

This study proposes to develop a real-time monitoring model that quantifies the dying cell percentage in lab-scale bioreactors using capacitance spectroscopy. The capacitance spectroscopy contains cell death-related information due to various physical properties changes during the cell death process, e.g., cytoplasmic conductivity change. The …

Development Of Polymeric Cxcr4 Targeting Carriers For Sirna Delivery To Treat Acute Kidney Injury, Weimin Tang

Theses & Dissertations

Acute kidney injury (AKI) is a major kidney disease that is characterized by a sudden loss of renal function which manifests by a decrease in urine output and an increase in serum creatinine. AKI is a global healthcare burden associated with high morbidity, mortality, and increasing cost. Currently there are no effective pharmacological treatments available. Apoptosis induced by p53 has been demonstrated as an important pathological mechanism for the development of AKI. Meanwhile, CXCR4/SDF-1 axis has been associated with the inflammation during AKI, and CXCR4 is overexpressed on injured tubules. This dissertation hypothesized that polycations with CXCR4 targeting ability could …

The Rotator Cuff Tendon-To-Bone Interface: Maturation, Aging, And 3d Bioprinting For Regeneration, Xiping Jiang

Theses & Dissertations

Rotator cuff tendon injuries often occur at the tendon-to-bone interface (i.e., enthesis) area with a high prevalence for the elderly population. In addition, regeneration of the gradient structure of the enthesis is still a significant clinical challenge. Our studies aim to identify the histological, molecular, and biomechanical alterations of the rotator cuff enthesis with maturation and aging, and develop a novel therapeutic method using three-dimensional (3D) bioprinting technique to regenerate a functional enthesis. Striking variations of the entheses were observed both histologically and biomechanically during the maturation process. The histological features did not show many differences at the insertion site …

Characterization Of Phase Behavior In Idp Solutions By Uv-Vis Spectrophotometry And Phase Volume Fraction Measurements In Capillaries, Qing Sun

Biomedical Engineering ETDs

Intrinsically disordered proteins (IDPs) play vital roles in cell signaling and regulation by changing conformation dynamically under various stimulus. Thus, it is crucial to understand their physical properties in vitro especially liquid-liquid phase separation (LLPS). Here, we first used UV-vis spectrophotometry to investigate two of IDPs' physical properties – transition temperature (Tt) and coacervate size. This deeper insight allows us to further understand the dynamics of phase growth. We then constructed a binodal curve in the phase diagram by measurement of volume ratios in phase separated IDP solution in glass capillaries.

Deep Learning Approach To Improved Image Quality For Medical Diagnostics, Olivia Loesch, Katie Leyba, Halyley Chan, Craig Goergen

Discovery Undergraduate Interdisciplinary Research Internship

The United Nation’s health-related Sustainable Development Goals are difficult to achieve in low- and middle-income countries due to workforce shortages and inadequate health surveillance systems. However, with the growth of artificial intelligence (AI) and computer algorithms, it is possible to apply AI to healthcare technologies to improve progress towards these UN standards. This project aims at using and improving computer algorithms and deep learning to aid in the extraction of important structural and functional information from murine carotid artery ultrasound and photoacoustic images. First, we created a large database of simulated photoacoustic images to optimize the algorithms. These images were …

Plasmonically-Enhanced Dna-Rna Hybrid-Based Bioassay For Amplification-Free Quantification Of Sars-Cov-2, Yuxiong Liu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Corona Virus Disease 2019 (COIVD-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a highly infectious respiratory illness. Within just a few months, it spread around the whole world and became a global pandemic. Real-time reverse-transcription polymerase chain reaction (RT-PCR) works as a gold standard method diagnosing COVID-19 with high sensitivity and specificity. But due to the programs of RT-PCR, it usually takes more than 24 hours to get the results while specialized devices are also required. False-negative results can happen as well using RT-PCR which increase the risk of spreading coronavirus. To promote quicker detection of COVID-19, …

Hydrology And Water Quality Analysis In The Big Black River Watershed, Mississippi, Moniba Shabbir

Theses and Dissertations

Evaluating hydrology and water quality for the Big Black River Watershed in Mississippi was accomplished by using the Better Assessment Science Integrating Point and Nonpoint Source (BASINS 4.5), Loading Simulation Program in C++ (LSPC), and Water Quality Analysis Simulation Program (WASP) models. The watershed model calibration was originally accomplished by using historical data collected from U.S. Geological Survey (USGS). The watershed model was calibrated using data from 2000 through 2018 in order to quantify stream flow and point source discharges under a variety of hydrologic conditions. The model predicted response of hydrology was consistent with the observed data range. The …

Design Of Plastic Contaminant Eliminator In Seed Cotton, Joshua H. Tandio

Theses and Dissertations

Plastic contamination in cotton is a problem in cotton industry and researchers have worked on this problem with different approaches. This thesis documents the design of mechanical and electronic real-time systems for detecting and removing plastic contaminants. The mechanical system was designed to expose plastic embedded inside the seed cotton to the sensor and to separate plastic contaminated cotton from the process stream. The detection system consisted of an embedded computer interfaced with a USB camera and Neural Network (NN) software running in it. Two NN models were tested, a transfer learning model and a built-from-scratch original model. The original …