Patient-Specific Finite Element Analysis For Mandibular Fracture Fixation, Ethan Snyder

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis proposes an approach for Finite Element Analysis (FEA) of mandibular fracture fixation. Using a Computerized Tomography (CT) scan of mandible obtained from a specific person, the material characteristics, density and modulus of elasticity, were determined from a set of discrete points within the mandible that are 1mm spaced based on the Hounsfield Units of these points. The mandible geometry was sectioned to simulate a fracture. Muscle and mastication forces were added to replicate post-surgery loading. Using a standard linear miniplate, this material model was compared with two commonly used mandibular cortical shell bone models: isotropic and orthotropic. A …

Computational Sentiment Analysis Of An Online Left Ventricular Assist Device Support Forum: Positivity Predominates, Melissa Austin, Abhiraj Saxena, Thomas O'Malley, Elizabeth Maynes, Henry Moncure, Nathan Ott, H. Todd Massey, Francesco Moscato, Antonio Loforte, John M Stulak, Vakhtang Tchantchaleishvili

Division of Cardiology Faculty Papers

Background: The impact of left ventricular assist device (LVAD) complications on the individual patient, overall sentiment, and its effect on referral patterns, is not fully understood. We sought to better understand patient attitudes towards LVAD therapy using a computational sentiment analysis approach.

Methods: Posts, comments, and titles were parsed from MyLVAD.com's HTML as a text file using custom Python scripts (version 3.6). Individual word frequency was computed with word classification as 'positive', 'negative', or 'neutral'. Data transformation and cleaning, sentiment determination, and analysis was performed with a binary dictionary package using R software (version 3.6).

Results: Sixty-six thousand eight hundred …

Bioink Optimization And Effects Of Microgravity On 3d Bioprinted Cell Laden Constructs, Likitha Somasekhar

Theses and Dissertations

Bioengineered 3D tissue constructs have gained attention as in vitro tools for the study of cell-cell and cell-matrix interactions and are being explored for potential use as experimental models for mimicking human tissues. One of the main problems in tissue engineering is the necessity to vascularize complex engineered tissues and sacrificial printing has been recognized as a possible solution to vascularization of the bioprinted tissues. Research studies have demonstrated that exposure to microgravity in space induces adaptive alterations in vascular structure and function. Changes in the morphology and gene expression is observed when endothelial cells are exposed to microgravity and …

In Vivo Analysis Of A Proprietary Glass-Based Adhesive For Sternal Fixation And Stabilization Using Rabbit And Sheep Models, Cina Mehrvar, Emily Deignan, Mark Hurtig, Gideon Cohen, Paul Zalzal, Oleg Safir, Adel Alhalawani, Marcello Papini, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Wire cerclage remains the standard method of care for sternal fixation, following median sternotomy, despite being beset with complications. An emerging treatment option has been to augment the wires with an adhesive. A patented ionomeric glass (mole fraction: SiO₂:0.48, ZnO:0.36, CaO:0.12, SrO:0.04) has been used to formulate GPC+, a glass polyalkenoate cement (GPC), by mixing it with poly(acrylic) acid (PAA) and de-ionized water. In a human cadaver study, this material, when applied with wire cerclage, was able to significantly reduce sternal instability. However, the material has yet to be tested in pertinent animal models. Here, after a series …

Electroencephalography Resting-State Networks In People With Stroke, Dylan B. Snyder, Brian D. Schmit, Allison S. Hyngstrom, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Introduction

The purpose of this study was to characterize resting-state cortical networks in chronic stroke survivors using electroencephalography (EEG).

Methods

Electroencephalography data were collected from 14 chronic stroke and 11 neurologically intact participants while they were in a relaxed, resting state. EEG power was normalized to reduce bias and used as an indicator of network activity. Correlations of orthogonalized EEG activity were used as a measure of functional connectivity between cortical regions.

Results

We found reduced cortical activity and connectivity in the alpha (p < .05; p = .05) and beta (p < .05; p = .03) bands after stroke while connectivity …

Evaluation Of Visible Diffuse Reflectance Spectroscopy In Liver Tissue: Validation Of Tissue Saturations Using Extracorporeal Circulation, Stylianos Voulgarelis, Faraneh Fathi, Astrid G. Stucke, Kevin D. Daley, Joohyun Kim, Michael W. Zimmerman, Johhny C. Hong, Nicholas Starkey, Kenneth P. Allen, Bing Yu

Biomedical Engineering Faculty Research and Publications

Significance: Real-time information about oxygen delivery to the hepatic graft is important to direct care and diagnose vascular compromise in the immediate post-transplant period.

Aim: The current study was designed to determine the utility of visible diffuse reflectance spectroscopy (vis-DRS) for measuring liver tissue saturation in vivo.

Approach: A custom-built vis-DRS probe was calibrated using phantoms with hemoglobin (Hb) and polystyrene microspheres. Ex vivo (extracorporeal circulation) and in vivo protocols were used in a swine model (n=15) with validation via blood gas analysis.

Results: In vivo absorption and scattering measured by vis-DRS with and without biliverdin …

Peptoid-Based Microsphere Coatings For Biomaterial Applications, Jesse Leland Roberts

Graduate Theses and Dissertations

Peptoids are peptidomimetic oligomers that predominantly harness similarities to peptides for biomimetic functionality. The incorporation of chiral, aromatic side chains in the peptoid sequence allows for the formation of distinct secondary structures and self-assembly into supramolecular assemblies, including microspheres. Peptoid microspheres can be coated onto substrates for potential use in biosensor technologies, tissue engineering platforms, and drug-delivery systems. They have the potential for use in biomedical applications due to their resistance to proteolytic degradation and low immunogenicity. This dissertation focuses on the physical characteristics and robustness of the peptoid microsphere coatings in various physiological conditions, along with their ability to …

Oxone® Mediated Tempo-Oxidized Cellulose Nanomaterials: Material Characterization, Ultrafiltration Membrane Separations, And Thin Film Composite Gas Transport Analysis, John Phillips Moore

Graduate Theses and Dissertations

Cellulose nanomaterials (CNMs) are derived from plant matter and are comprised of nanoscopic cellulose crystals and fibers. They have a diverse set of applications, from cosmetics to oil recovery. This study focuses on the properties of Oxone® mediated TEMPO-oxidized cellulose nanomaterials (OTO-CNMs) and their use in controlling the transport properties of polymeric substrates. Synthesis and characterization of cellulosic nanoparticles have resulted in the creation of OTO-CNMs with properties that increase hydrophilicity. With added hydrophilicity, OTO-CNMs possess lower fouling propensity, making them ideal membrane additive for transport limited separations such as hemodialysis.

To utilize the material and unique properties thereof, this …

Calibration Of Opensim Lifting Full-Body Model For Dynamic Simulations Of Patient-Handling Maneuvers, Barry Bait, Bridget Gagnier

20th Annual Celebration of Undergraduate Research and Creative Activity (2021)

Manual patient-handling tasks are associated with lower-back pain and injury. Computational musculoskeletal models may determine forces on the low back, trunk muscle activation during these tasks, and provide insight on how these may result in injury. There are no publicly available models for these tasks. To determine the appropriateness of the OpenSim Full-Body Lifting Model for these tasks, this project calibrated the model with biomechanical data of simulated maneuvers performed by a test subject. Thirty-nine reflective markers were placed bilaterally on bony prominences (forehead, back of head, clavicle, sternum, C7, T10, epicondyle of humerus, styloid process, metacarpal, anterior and posterior …

Mems Directional Acoustic Sensors, Colby Damren

Thinking Matters Symposium

The purpose of my project is to test and verify two Micro-Electro-Mechanical-System (MEMS) microphones. The two MEMS devices are biomimetic microphones that imitate the eardrums of the Ormia Ochracea, a parasitic fly that listens for host crickets to lay their eggs. The MEMS microphones mimic the eardrum spacing of the Ormia Ochracea with a spacing of 1000um. This is roughly twice the opening of the Ormia Ochracea. The microphones will be tested for directionality inside a wooden box. This box will be lined with beveled foam to prevent any echo or outside noise from interfering with the results. These results …

Nitinol Robotic Arm, Brandon Cousino, Connor Sweatt

Thinking Matters Symposium

The goal of our project is to create a remotely controlled robotic arm using a nickel-titanium alloy (Nitinol) that exhibits “shape memory” tendencies and a 9-lumen tube. The arm must be able to move in all for directions (forward, left, right, backwards) with the control of a joystick and return to an upright position upon halting user input (thus requiring a two-way shape memory ability). The final product must operate without any unwanted twisting of the arm, crosstalk between the different nitinol wires due to heating, and be easily manufacturable. Easy replacement of the arm from the main mechanism is …

Design, Simulation And Testing Of Biomimetic Directional Acoustic Sensors, Brendan Francis

Thinking Matters Symposium

The Ormia ochracea, a species of parasitic fly, has become the focal point in sound localization research because of its finely tuned hearing abilities. The female of this species uses its super highly directional hearing to pinpoint the call of a host cricket, with hypersensitivity of frequency and phase difference, to reach and dispose of its eggs on the host. The goal of this study was to further the research of a previous Project in Professor Guvench’s group which implemented MEMS (Micro Electro-Mechanical System) technology on a chip to replicate these abilities. In this iteration, however, some commercially available …

Biomedical Applications And Syntheses Of Selected Anthraquinone Dyes, Richard Sirard

Senior Honors Theses

Anthraquinones are aromatic organic compounds that have multiple applications in the biomedical field. Some anthraquinone-based compounds are used as fluorophores to contrast cell nuclei while others act as chemotherapeutic agents. However, there are not many fluorescent anthraquinone cell stains currently available. In this study, commercially available anthraquinone dyes, in addition to other dye families and compounds, were reviewed for their unique properties, advantages, and drawbacks. The development and characterization of three novel anthraquinone fluorophores revealed promising photophysical characteristics, like large Stokes shifts. One of the compounds, RBS3, was chosen for fixed and live cell staining and exhibited desirable biomedical properties. …

A Brief Bibliometric Survey Of Explainable Ai In Medical Field, Nilkanth Mukund Deshpande, Shilpa Shailesh Gite

Library Philosophy and Practice (e-journal)

_{^{Background: This study aims to analyze the work done in the field of explainability related to artificial intelligence, especially in the medical field from 2004 onwards using the bibliometric methods.}}

_{^{Methods: different articles based on the topic leukemia detection were retrieved using one of the most popular database- Scopus. The articles are considered from 2004 onwards. Scopus analyzer is used for different types of analysis including documents by year, source, county and so on. There are other different analysis tools such as VOSviewer Version 1.6.15. This is used for the analysis of different units such as co-authorship, co-occurrences, citation analysis …}}

Differential White Blood Cell Counting, Gregory Austin

Honors Scholar Theses

This thesis was completed with the goal of developing a model for the detection and differentiation of 8 different classes of white blood cells. Manual differential counting can be a time consuming and laborious task that would greatly be improved by an automated system. The model created in this project was to be used to automatically determine the number of each cell type in a sample, greatly reducing the need for manual counting. The model was produced using a convolutional neural network that utilized transfer learning from MobileNet_V2, an image recognition network produced by Google. After 20 epochs of training …

Highly Branched Polymers Based On Poly(Amino Acid)S For Biomedical Application, Marisa Thompson, Carmen Scholz

PRC-Affiliated Research

Polymers consisting of amino acid building blocks continue to receive consideration for biomedical applications. Since poly(amino acid)s are built from natural amino acids, the same building blocks proteins are made of, they are biocompatible, biodegradable and their degradation products are metabolizable. Some amino acids display a unique asymmetrical AB2 structure, which facilitates their ability to form branched structures. This review compares the three forms of highly branched polymeric structures: structurally highly organized dendrimers, dendrigrafts and the less organized, but readily synthesizable hyperbranched polymers. Their syntheses are reviewed and compared, methods of synthesis modulations are considered and variations on their traditional …

Highly Branched Polymers Based On Poly(Amino Acid)S For Biomedical Application, Marisa Thompson, Carmen Scholz

PRC-Affiliated Research

Polymers consisting of amino acid building blocks continue to receive consideration for biomedical applications. Since poly(amino acid)s are built from natural amino acids, the same building blocks proteins are made of, they are biocompatible, biodegradable and their degradation products are metabolizable. Some amino acids display a unique asymmetrical AB2 structure, which facilitates their ability to form branched structures. This review compares the three forms of highly branched polymeric structures: structurally highly organized dendrimers, dendrigrafts and the less organized, but readily synthesizable hyperbranched polymers. Their syntheses are reviewed and compared, methods of synthesis modulations are considered and variations on their traditional …

Preclinical Development Of Single Walled Carbon Nanotube-Based Optical Biosensors, Eric M. Hofferber

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

High resolution, long-term monitoring of key biological analytes would improve patient outcomes by providing earlier detection of disease states and improved efficacy of treatment. One class of biosensors that have gained much attention in recent years are optical biosensors. Optical probes are attractive biosensors due to their noninvasive nature of detection, as certain light can pass through tissue, water, and blood. Single walled carbon nanotubes (SWNT) are a specific type of optical biosensor that fluoresce in the near infrared range of the electromagnetic spectrum and offer unparalleled spatial and temporal resolution. SWNT have been applied as biosensors in vitro, …

Optimum Double Rhombic Flap Design For Z-Plasty, Abdullah Khan

Honors Theses

In the medical field, especially in plastic surgery, Rhombic flap and z-plasty are common methods in surgical procedures to treat and close complex wounds of different types of injuries/surgery. Each conventional surgical method has its own pros and cons. When both conventional methods join, it would complement each other weaknesses. This senior design project purpose is to investigate the magnitude of stresses build on skin due to transposing of skin in these methods when the wound is close after the surgical procedure is done. In this project a combination of rhombic flap and z-plasty is studied which is Double Rhombic …

Surface-Eroding Drug Delivery Films For Sequential And/Or Intermittent Release Of Psychoactive Drugs, Jason Price

Honors Theses

ABSTRACT JASON BLAKE PRICE: Surface-Eroding Drug Delivery Films for Sequential and/or

Intermittent Release of Psychoactive Drugs For patients with psychiatric diseases, adherence to medication schedules, medication

errors, and abuse are common issues. Promising new forms of therapy for these patients, such as micro-dosed lysergic acid diethylamide (LSD), where patients receive 10-20% of a full dose every third day, present further drug delivery challenges. Sequential or intermittent release of drugs from an implanted device could ensure long-term drug compliance, automate drug dosing during the life of the implant, and eliminate potential for abuse and medication errors. To this end, we generated …

Understanding The Effect Of Adaptive Mutations On The Three-Dimensional Structure Of Rna, Justin Cook

Undergraduate Research and Scholarship Symposium

Single-nucleotide polymorphisms (SNPs) are variations in the genome where one base pair can differ between individuals.¹ SNPs occur throughout the genome and can correlate to a disease-state if they occur in a functional region of DNA.¹According to the central dogma of molecular biology, any variation in the DNA sequence will have a direct effect on the RNA sequence and will potentially alter the identity or conformation of a protein product. A single RNA molecule, due to intramolecular base pairing, can acquire a plethora of 3-D conformations that are described by its structural ensemble. One SNP, rs12477830, which …

Project Alien, Rebecca Mccallin, Madelyn Hoying, Alex Evans, Matthew Nestler, Karli Rae Sutton, Garett Craig, Lucia Secaia Del Cid, Alexander Guy, Rachel Fernandez, Amanda Trusiak, Paige Aley, Ingabire Gakwerere, Nina Dorfner, Maria Mosbacher, Mary Flavin, Selvin Hernandez, Audrey Steen, Benjamin Kazimer

Undergraduate Research and Scholarship Symposium

Project ALIEN is a comprehensive plan to send humans to Mars to look for life on the Martian surface while exploring the viability and adaptability of terrestrial microbes in Martian atmospheric conditions. ALIEN will use a ballistic capture trajectory to get to Mars and stay in aerostationary orbit for a 30-day surface mission, during which two surface crewmembers will perform a variety of experiments to achieve the mission’s goals of Martian microbial discovery within brines of the Gale Crater and terrestrial microbe adaptability and viability to Martian conditions. Experimentation is based on the presumption that Martian microbes are metabolically similar …

Bioprinting Alginate Structures Using The Fresh Method, Amanda Pellegrino

Undergraduate Research and Scholarship Symposium

Three-dimensional bioprinting is a tissue engineering and regenerative medicine technique that utilizes biomaterials to print clinically relevant scaffolds. These scaffolds are used for tissue repair and to treat disease, such as end-organ failure. The main problem with 3D bioprinting is its inability to print soft biomaterials, which collapse due to gravitational forces. In addition, the materials that can be used do not mimic native tissue’s mechanical properties and texture. To combat this, Dr Feinberg’s laboratory at Carnegie Mellon University developed the freeform reversible embedding of suspended hydrogels (FRESH) method. The FRESH method allows for soft biomaterials to be supported in …

Développement D'Une Méthode De Mesure De L'Exposition Sonore Effective Intraauriculaire Pour Une Utilisation En Milieu De Travail, Hugues Nélisse, Fabien Bonnet, Marcos Nogarolli, Jérémie Voix

Rapports de recherche scientifique

De nombreux travailleurs sont exposés quotidiennement à des niveaux de bruit susceptibles d'endommager leur audition. De ce fait, la mesure de l'exposition sonore est essentielle afin d'identifier et d’évaluer des solutions correctives pour protéger adéquatement les travailleurs. Cependant, les méthodes et les technologies de mesure actuelles ne permettent généralement pas de déterminer avec précision l'exposition au bruit subie par un individu sur son lieu de travail. La dosimétrie intraauriculaire est une solution prometteuse pour pallier un certain nombre de problèmes liés aux méthodes de mesure conventionnelles, mais cette méthodologie est fragilisée de trois façons : 1) l'exposition sonore mesurée dans …

Automatic Generation And Novel Validation Of Patient-Specific, Anatomically Inclusive Scoliosis Models For Biomechanics-Informed Surgical Planning, Austin Tapp, Michel Audette, James Bennett

College of Engineering & Technology (Batten) Posters

Scoliosis is an abnormal spinal curvature of greater than 10 degrees. Severe scoliotic deformities are addressed with highly invasive procedures: anterior or posterior spinal fusion approaches. This invasiveness is due, in part, to the constraints of current surgical planning, which utilizes computed tomography (CT) scans unable to discern spinal ligaments that are dissected to make the spine sufficiently compliant for correction. If localization of ligaments and soft tissues were achieved pre-operatively, corrective procedures could become safer and more efficient by using finite element (FE) biomechanical simulations to determine decreased incidences of ligament releases. This research aims to achieve ligament localization …

High Throughput And On-Chip Analysis Of Engineered Extracellular Nano-Vesicles And Their Functional Characterizations, Brendan Johnson, Jiayi Zhang

Bioengineering Senior Theses

In recent years, extracellular vesicles (EVs) have shown great promises as drug delivery vehicles to treat various diseases, including cancer and neurological diseases. EV surface engineering is a critical step to achieve targeted drug delivery. By engineering EVs with transmembrane scaffolds, targeting molecules can be displayed on the EV outer surface, and cargos can be loaded into the EV lumen. However, EV heterogeneity and inadequate EV purification and characterization methods impose great challenges on understanding engineered EVs and choosing appropriate transmembrane scaffolds. To this day, surface engineered EVs are still limited to lab research. In this thesis, we modify the …

Musculoskeletal Modeling Of The Pelvis And Lumbar Spine During Running, Ruth Higgins, Maryam Moeini, Hunter Bennett, Stacie Ringleb

College of Engineering & Technology (Batten) Posters

Musculoskeletal modeling provides an alternative to in-vivo characteristics that are difficult to directly measure for movements such as running, especially for trunk muscles and joints. The full-body-lumbar-spine (FBLS) model by Raabe and Chaudhari, 2016 is an OpenSim model created for simulations of jogging. The lifting full-body (LFB) model by Beaucage-Gauvreau et al., 2018 is an adaptation of the FBLS created for estimating spinal loads during lifting. PURPOSE: Determine validity of the FBLS and LFB models in simulating pelvis and lumbar spine kinematics during running. METHODS: Inverse Kinematics were executed using experimental data for the FBLS and LFB models. To …

3d Lidar Human Skeleton Estimation For Long Range Identification, Alexander Glandon, Lasitha Vidyaratne, Nasrin Sadeghzadehyazdi, Nibir Dhar, Jide Familoni, Scott Acton, Khan Iftekharuddin

College of Engineering & Technology (Batten) Posters

This research project is the continuation of an effort by the Vision Lab to understand human gait and motion using special-purpose imaging sensors and novel computer vision algorithms. The project began using a Motion Capture (MoCap) system which measures 3D human skeleton information in real-time by attaching markers to a human subject and viewing the human motion with a set of cameras at different angles. We developed an algorithm to determine the gender of a subject wearing these sensors. The current phase of this project extends this work using a state-of-the-art flash Lidar sensor. This sensor scans the surface of …

Cyclophilin D Is A Sensor Of Nano-Pulse Stimulation, Brittney Ruedlinger, Bani Hani Maisoun, Lucas Potter, Nicola Lai, Stephen J. Beebe

The Graduate School Posters

Nano-Pulse Stimulation (NPS), a pulsed power-derived technology, stimulates structural and functional changes in plasma membranes and cellular organelles. NPS induces a Ca²⁺ influx and opening of the mitochondrial permeability transition pore (mPTP) that dissipates the mitochondrial membrane potential (ΔΨ_m) and, when sustained, induces regulated cell death. Here we show that in rat cardiomyoblasts (H9C2) cyclophilin D (CypD) is a mitochondrial sensor for NPS as defined by observations that loss of ΔΨ_m is Ca²⁺ and mitochondrial reactive oxygen species (mROS) dependent and cyclosporin A (CsA)-sensitive, which are diagnostic qualities for effects on CypD and the mPTP. …

Trials And Tribulations Of Humanizing Mice For Cancer Research, Brittney Ruedlinger, Steven Warsof, Eric Feliberti, Mary Beth Hughes, Ayobami ‘Edwin’ Oshin, Chunqi Jiang, Brittany P. Lassiter, Siqi Guo, Stephen J. Beebe

The Graduate School Posters

Cancers are aggressive, evasive, and ruthless killers, claiming millions of lives every year. Cancers are heterogeneous and there is often no single, clearly defined problem as they harness and manipulate a multitude of fundamental mechanisms at the very essence of life. To investigate these mechanisms and vet potential interventive therapies, humanized mice offer a unique model as a prelude to the use of nanosecond pulse stimulation (NPS), a pulse power technology applying nanosecond duration, high electric field pulses, to ablate human tumors. Immunodeficient mouse strains, NSG and NSG-SGM3, were engrafted with human immune cells and human tumors, which would allow …