Medicine and Health Sciences Commons^™

Finite Element Simulation And Additive Manufacturing Of Stiffness-Matched Niti Fixation Hardware For Mandibular Reconstruction Surgery, Ahmadreza Jahadakbar, Narges Shayesteh Moghaddam, Amirhesam Amerinatanzi, David Dean, Haluk E. Karaca, Mohammad Elahinia

Mechanical Engineering Faculty Publications

Process parameters and post-processing heat treatment techniques have been developed to produce both shape memory and superelastic NiTi using Additive Manufacturing. By introducing engineered porosity, the stiffness of NiTi can be tuned to the level closely matching cortical bone. Using additively manufactured porous superelastic NiTi, we have proposed the use of patient-specific, stiffness-matched fixation hardware, for mandible skeletal reconstructive surgery. Currently, Ti-6Al-4V is the most commonly used material for skeletal fixation devices. Although this material offers more than sufficient strength for immobilization during the bone healing process, the high stiffness of Ti-6Al-4V implants can cause stress shielding. In this paper, …

Design Of A Modified Stewart Platform Manipulator For Misalignment Correction, Adekunle Ayoko

Master of Technology Management Plan II Graduate Projects

This thesis work is about the design of a modified Stewart platform manipulator for misalignment correction. The common version of the Stewart platform uses six actuators. The traditional Stewart platform of this kind has a moving top plate and a fixed base plate. However, in this research, the modified design of the traditional Stewart platform is studied. It is designed to be an easy connect-disconnect platform that can wrap around different structures with different cross sections and symmetrically designed. It is able to adjust position easily by using four identical but independent linear actuators populated evenly in two parts fastened …

The Role Of Scapular Morphology In Reverse Shoulder Arthroplasty, Ashish Gupta

Electronic Thesis and Dissertation Repository

Baseplate fixation in a reverse shoulder arthroplasty depends on adequate bone stock. In cases of severe glenoid bone loss and revision shoulder arthroplasty, deficiency of the glenoid vault compels the surgeon to attain screw fixation in the three columns of the scapula. The relationship of these columns demonstrated that the coracoid is closer to the lateral scapular pillar in females than in males. Significant gender dimorphism exists between the orientations of the three columns. The gender dimorphism is further evaluated by anthropometric measurements of the scapular body and the glenoid. The clinical significance lies in the ability to reconstruct the …

Sensitivity Analysis Of Geometry Changes In The Simulation Of Basilar Aneurysms, Paul Eserkaln

Theses and Dissertations

Computer simulation is a useful tool in the research and treatment of basilar aneurysms. Current technology allows researchers to create 3D models from cerebral vasculature in-vivo, allowing for the investigation of surgical options with minimal risk to the patient. The method used to construct these models overlooks smaller lateral arterial branches which are difficult to discern due to resolution limits of the imaging process. These lateral branches have minimal impact on the overall blood flow through the basilar artery, but they play a significant role in the health of the patient, so it is important to ensure sufficient blood will …

A Multi-Channel 3d-Printed Bioreactor For Evaluation Of Growth And Production In The Microalga Dunaliella Sp, Cristian A. Cox

Electronic Theses and Dissertations

We explored the capabilities of additive manufacturing using a photo-cured jetted material 3D printer to manufacture a milli-microfluidic device with direct application in microalgae Dunaliella sp growth and intracellular compounds biosynthesis tests. A continuous microbioreactor for microalgae culture was CAD designed and successfully built in 1 hour and 49 minutes using black photopolymer cured by UV and a support material. The microreactor was made up of 2 parts including the bioreactor itself and a microchannel network for culture media fluids and microalgae. Both parts were assembled to form a single unit. Additional optical and auxiliar components were added. An external …

Mechanism Of Interaction Of Peptide Modified Nanoparticles With Porphyromonas Gingivalis., Ankita Jain

Electronic Theses and Dissertations

Studies suggest that P. gingivalis functions as a keystone pathogen and interacts with primary colonizers in the supragingival biofilm such as S. gordonii. This interaction contributes to the initial colonization of the oral cavity by P. gingivalis and thus represents a potential target for therapeutic intervention. We have identified a peptide (BAR) derived from the streptococcal SspB protein that functions to inhibit P. gingivalis adherence to S. gordonii. In addition, we showed that nanoparticles (NPs) functionalized with BAR inhibit this interaction more potently than free soluble peptide, possibly by promoting interaction with P. gingivalis at higher valency than …

The Effects Of Cryopreservation On Human Dental Pulp-Derived Mesenchymal Stem Cells, Allison Elaine Tomlin

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many studies have demonstrated clinical applications for the use of dental pulp stem cells (DPSC) for the treatment of various conditions. This has driven medical and scientific interest in the collection, isolation and banking of DPSC tissues for research into these potential therapies. Few studies to date have evaluated the viability of DPSC following long-term cryopreservation. The purpose of this study is to evaluate the effects of cryopreservation on dental pulp-derived stem cells (DPSC) viability over a period of three years. Dental pulp-derived stem cells were isolated and cultured from thirty-one healthy teeth. DPSC isolates were assessed for doubling-time and …

Optical Coherence Photoacoustic Microscopy (Oc-Pam) For Multimodal Imaging, Xiaojing Liu

FIU Electronic Theses and Dissertations

Optical coherence tomography (OCT) and Photoacoustic microscopy (PAM) are two noninvasive, high-resolution, three-dimensional, biomedical imaging modalities based on different contrast mechanisms. OCT detects the light backscattered from a biological sample either in the time or spectral domain using an interferometer to form an image. PAM is sensitive to optical absorption by detecting the light-induced acoustic waves to form an image. Due to their complementary contrast mechanisms, OCT and PAM are suitable for being combined to achieve multimodal imaging.

In this dissertation, an optical coherence photoacoustic microscopy (OC-PAM) system was developed for in vivo multimodal retinal imaging with a pulsed broadband …

Raman Spectroscopy Detects Distant Invasive Brain Cancer Cells Centimeters Beyond Mri Capability In Humans, Michael Jermyn, Joannie Desroches, Jeanne Mercier, Karl St-Arnaud

Dartmouth Scholarship

Surgical treatment of brain cancer is limited by the inability of current imaging capabilities such as magnetic resonance imaging (MRI) to detect the entirety of this locally invasive cancer. This results in residual cancer cells remaining following surgery, leading to recurrence and death. We demonstrate that intraoperative Raman spectroscopy can detect invasive cancer cells centimeters beyond pathological T1-contrast-enhanced and T2-weighted MRI signals. This intraoperative optical guide can be used to detect invasive cancer cells and minimize post-surgical cancer burden. The detection of distant invasive cancer cells beyond MRI signal has the potential to increase the effectiveness of surgery and directly …

Multi-Classifier Fusion Strategy For Activity And Intent Recognition Of Torso Movements, Abhijit Kadrolkar

Doctoral Dissertations

As assistive, wearable robotic devices are being developed to physically assist their users, it has become crucial to develop safe, reliable methods to coordinate the device with the intentions and motions of the wearer. This dissertation investigates the recognition of user intent during flexion and extension of the human torso in the sagittal plane to be used for control of an assistive exoskeleton for the human torso. A multi-sensor intent recognition approach is developed that combines information from surface electromyogram (sEMG) signals from the user’s muscles and inertial sensors mounted on the user’s body. Intent recognition is implemented by following …

Use Of A Modified Greenscreen Tool To Conduct A Screening-Level Comparative Hazard Assessment Of Conventional Silver And Two Forms Of Nanosilver., Jennifer Sass, Lauren Heine, Nina Hwang

Environmental and Occupational Health Faculty Publications

BACKGROUND: Increased concern for potential health and environmental impacts of chemicals, including nanomaterials, in consumer products is driving demand for greater transparency regarding potential risks. Chemical hazard assessment is a powerful tool to inform product design, development and procurement and has been integrated into alternative assessment frameworks. The extent to which assessment methods originally designed for conventionally-sized materials can be used for nanomaterials, which have size-dependent physical and chemical properties, have not been well established. We contracted with a certified GreenScreen profiler to conduct three GreenScreen hazard assessments, for conventional silver and two forms of nanosilver. The contractor summarized publicly …

Intraocular Pressure Sensing And Control For Glaucoma Research, Simon Antonio Bello

USF Tampa Graduate Theses and Dissertations

Animal models of ocular hypertension are important for glaucoma research but come with experimental costs. Available methods of intraocular pressure (IOP) elevation are not always successful, the amplitude and time course of IOP changes are unpredictable and irreversible, and IOP measurement by tonometry is laborious. This dissertation focuses on the development and implementation of two novel systems for monitoring and controlling IOP without these limitations. The first device consists of a cannula implanted in the anterior chamber of the eye, a pressure sensor that continually measures IOP, and a bidirectional pump driven by control circuitry that can infuse or withdraw …

Synthesis, Characterization, And Application Of Monosized Mesoporous Silica Nanoparticle-Supported Lipid Bilayers For Targeted Therapeutic Delivery To Individual Cells, Paul Durfee

Biomedical Engineering ETDs

Mesoporous silica nanoparticle (MSNP) supported-lipid bilayers, termed ‘protocells,’ represent a potentially transformative class of therapeutic and theranostic delivery vehicles. The field of targeted drug delivery poses considerable challenges that cannot be addressed with a single ‘magic bullet’. Consequently, the protocell has been designed as a modular platform composed of interchangeable biocompatible components. The mesoporous silica core can have variable size and shape to direct biodistribution and controlled pore size and surface chemistry to accommodate diverse cargos. The encapsulating supported lipid bilayer can be modified with targeting and trafficking ligands as well as polyethylene glycol (PEG) to effect selective binding, endosomal …

Lipid Coated Microbubbles And Low Intensity Pulsed Ultrasound Enhance Chondrogenesis Of Human Mesenchymal Stem Cells In 3d Printed Scaffolds, Mitra Aliabouzar, Lijie Grace Zhang, Kausik Sarkar

Medicine Faculty Publications

Lipid-coated microbubbles are used to enhance ultrasound imaging and drug delivery. Here we apply these microbubbles along with low intensity pulsed ultrasound (LIPUS) for the first time to enhance proliferation and chondrogenic differentiation of human mesenchymal stem cells (hMSCs) in a 3D printed poly-(ethylene glycol)-diacrylate (PEG-DA) hydrogel scaffold. The hMSC proliferation increased up to 40% after 5 days of culture in the presence of 0.5% (v/v) microbubbles and LIPUS in contrast to 18% with LIPUS alone. We systematically varied the acoustic excitation parameters—excitation intensity, frequency and duty cycle—to find 30 mW/cm2, 1.5 MHz and 20% duty cycle to be optimal …

Neurosurgical Ultrasound Pose Estimation Using Image-Based Registration And Sensor Fusion - A Feasibility Study, Utsav Pardasani

Electronic Thesis and Dissertation Repository

Modern neurosurgical procedures often rely on computer-assisted real-time guidance using multiple medical imaging modalities. State-of-the-art commercial products enable the fusion of pre-operative with intra-operative images (e.g., magnetic resonance [MR] with ultrasound [US] images), as well as the on-screen visualization of procedures in progress. In so doing, US images can be employed as a template to which pre-operative images can be registered, to correct for anatomical changes, to provide live-image feedback, and consequently to improve confidence when making resection margin decisions near eloquent regions during tumour surgery.

In spite of the potential for tracked ultrasound to improve many neurosurgical procedures, it …

Comparing Machine Learning And Logistic Regression Methods For Predicting Hypertension Using A Combination Of Gene Expression And Next-Generation Sequencing Data, Elizabeth Held, Joshua Cape, Nathan L. Tintle

Faculty Work Comprehensive List

Machine learning methods continue to show promise in the analysis of data from genetic association studies because of the high number of variables relative to the number of observations. However, few best practices exist for the application of these methods. We extend a recently proposed supervised machine learning approach for predicting disease risk by genotypes to be able to incorporate gene expression data and rare variants. We then apply 2 different versions of the approach (radial and linear support vector machines) to simulated data from Genetic Analysis Workshop 19 and compare performance to logistic regression. Method performance was not radically …

Electro-Chemotactic Fields Induce Cooperative Movement Of Cns Cells, Shawn Mishra, Stephen Redenti, Maribel Vazquez

Publications and Research

Vision loss in adults with Age Related Macular Degeneration (AMD) is attributed to damage of retinal photoreceptor cells that initiate vision by absorbing light. Mouse models have suggested that transplantation of precursor cells may be a novel approach to restore vision. This project uses a combination of electrotactic and chemotactic stimuli to promote and guide CNS cell migration within a microdevice model.

Long-Term Biocompatibility, Imaging Appearance And Tissue Effects Associated With Delivery Of A Novel Radiopaque Embolization Bead For Image-Guided Therapy, Karun Sharma, Zainab Bascal, Hugh Kilpatrick, Koorosh Ashrafi, Sean L. Willis, Matthew R. Dreher, Andrew L. Lewis

Pediatrics Faculty Publications

The objective of this study was to undertake a comprehensive long-term biocompatibility and imaging assessment of a new intrinsically radiopaque bead (LC Bead LUMI™) for use in transarterial embolization. The sterilized device and its extracts were subjected to the raft of ISO10993 biocompatibility tests that demonstrated safety with respect to cytotoxicity, mutagenicity, blood contact, irritation, sensitization, systemic toxicity and tissue reaction. Intra-arterial administration was performed in a swine model of hepatic arterial embolization in which 0.22–1 mL of sedimented bead volume was administered to the targeted lobe(s) of the liver. The beads could be visualized during the embolization procedure with …

A Fourier Description Of Covariance, And Separation Of Simultaneously Encoded Slices With In-Plane Acceleration In Fmri, Mary C. Kociuba

Dissertations (1934 -)

Functional magnetic resonance imaging (fMRI) studies aim to identify localized neural regions associated with a cognitive task performed by the subject. An indirect measure of the brain activity is the blood oxygenation level dependent (BOLD) signal fluctuations observed within the complex-valued spatial frequencies measured over time. The standard practice in fMRI is to discard the phase information after image reconstruction, even with evidence of biological task-related change in the phase time-series. In the first aim of this dissertation, a complex-valued time-series covariance is derived as a linear combination of second order temporal Fourier frequency coefficients. As opposed to magnitude-only analysis, …

An Interactive Videogame Designed To Improve Respiratory Navigator Efficiency In Children Undergoing Cardiovascular Magnetic Resonance, Sean M. Hamlet, Christopher M. Haggerty, Jonathan D. Suever, Gregory J. Wehner, Jonathan D. Grabau, Kristin N. Andres, Moriel H. Vandsburger, David K. Powell, Vincent L. Sorrell, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

Background: Advanced cardiovascular magnetic resonance (CMR) acquisitions often require long scan durations that necessitate respiratory navigator gating. The tradeoff of navigator gating is reduced scan efficiency, particularly when the patient’s breathing patterns are inconsistent, as is commonly seen in children. We hypothesized that engaging pediatric participants with a navigator-controlled videogame to help control breathing patterns would improve navigator efficiency and maintain image quality.

Methods: We developed custom software that processed the Siemens respiratory navigator image in real-time during CMR and represented diaphragm position using a cartoon avatar, which was projected to the participant in the scanner as visual feedback. The …

Imaging Right Ventricular Function To Predict Outcome In Pulmonary Arterial Hypertension, Alessandro Bellofiore, Melanie Brewis, Rebecca Vanderpool, Naomi Chesler, Martin Johnson, Robert Naeije, Andrew Peacock

Faculty Publications

Right ventricular (RV) function is a major determinant of outcome in pulmonary arterial hypertension (PAH). However, uncertainty persists about the optimal method of evaluation.MethodsWe measured RV end-systolic and end-diastolic volumes (ESV and EDV) using cardiac magnetic resonance imaging and RV pressures during right heart catheterization in 140 incident PAH patients and 22 controls. A maximum RV pressure (Pmax) was calculated from the nonlinear extrapolations of early and late systolic portions of the RV pressure curve. The gold standard measure of RV function adaptation to afterload, or RV–arterial coupling (Ees/Ea) was estimated by the stroke volume (SV)/ESV ratio (volume method) or …

Microdose Fluorescence Imaging Of Aby-029 On An Operating Microscope Adapted By Custom Illumination And Imaging Modules, Jonathan T. Elliott, Alisha V. Dsouza, Kayla Marra, Brian W. Pogue, David Roberts, Keith Paulsen

Dartmouth Scholarship

Fluorescence guided surgery has the potential to positively impact surgical oncology; current operating microscopes and stand-alone imaging systems are too insensitive or too cumbersome to maximally take advantage of new tumor-specific agents developed through the microdose pathway. To this end, a custom-built illumination and imaging module enabling picomolar-sensitive near-infrared fluorescence imaging on a commercial operating microscope is described. The limits of detection and system specifications are characterized, and in vivo efficacy of the system in detecting ABY-029 is evaluated in a rat orthotopic glioma model following microdose injections, showing the suitability of the device for microdose phase 0 clinical trials.

Application Of Bioinstrumentation In Developing A Pressure Suit For Suborbital Flight, Pedro Llanos, Erik Seedhouse

Publications

This presentation features Embry-Riddle Aeronautical University's U-2 pressure suit. Built to be light and cost-effective, this suit is comfortable, comes in multiple sizes, operates in pressures up to 5 PSID, has an active airflow-based cooling system, and features bio-instrumentation to measure heart rate, breathing rate, skin temperature and other vitals.

Selecting Medical Hardware Using Pairwise Comparisons: A Patient's Perspective Of Cochlear Implant Device Selection, Timothy R. Anderson, Shabnam Razeghian Jahromi

Engineering and Technology Management Faculty Publications and Presentations

Selecting medical hardware can be a difficult and permanent decision for patients that they are often unprepared for. The authors explore the use of pairwise comparison techniques to better inform medical decision making in an application of choosing between three major cochlear implant manufacturers. This paper appears to be the first study to apply a pairwise comparison decision making approach for cochlear implant device selection. Also, unlike many medical decision making studies that are developed by the healthcare professional, this model and analysis was conducted entirely by the patient for the purpose of making the real-world decision of a device. …

Diffuse Optical Measurements Of Head And Neck Tumor Hemodynamics For Early Prediction Of Chemoradiation Therapy Outcomes, Lixin Dong, Mahesh Kudrimoti, Daniel Irwin, Li Chen, Sameera Kumar, Yu Shang, Chong Huang, Ellis L. Johnson, Scott D. Stevens, Brent J. Shelton, Guoqiang Yu

Biomedical Engineering Faculty Publications

This study used a hybrid near-infrared diffuse optical instrument to monitor tumor hemodynamic responses to chemoradiation therapy for early prediction of treatment outcomes in patients with head and neck cancer. Forty-seven patients were measured once per week to evaluate the hemodynamic status of clinically involved cervical lymph nodes as surrogates for the primary tumor response. Patients were classified into two groups: complete response (CR) (n = 29) and incomplete response (IR) (n = 18). Tumor hemodynamic responses were found to be associated with clinical outcomes (CR/IR), wherein the associations differed depending on human papillomavirus (HPV-16) status. In HPV-16 …

Controlled Delivery Of Angiogenic And Arteriogenic Growth Factors From Biodegradable Poly(Ester Amide) Electrospun Fibers For Therapeutic Angiogenesis, Somiraa S. Said

Electronic Thesis and Dissertation Repository

Therapeutic angiogenesis relies on the delivery of exogenous growth factors to stimulate neovessel formation. However, systemic administration of angiogenic factors results in rapid clearance from the site of interest due to their short biological half-life. In this work, we are reporting controlled delivery of a ‘cocktail’ of growth factors, an angiogenic factor −fibroblast growth factor-2 (FGF2), and an arteriogenic factor −fibroblast growth factor-9 (FGF9), from biodegradable poly(ester amide) (PEA) electrospun fibers towards targeting neovascular formation and maturation. FGF2 and FGF9 were dual loaded into PEA fibers using a mixed blend and emulsion electrospinning technique. Matrigel tube formation and Boyden chamber …

Development Of Standard Criteria To Evaluate The Effectiveness Of Helmets At Decreasing The Risk Of Concussions, Daniel Y. Shyu, Goutham N. Sankaran, Kevin G. Mciver, Nicolas Leiva, Eric A. Nauman

The Summer Undergraduate Research Fellowship (SURF) Symposium

In many sports, such as American football, accumulations of mild traumatic brain injuries have been suggested as a possible link to neurodegeneration and future mental disorders. With head impacts occurring at all levels of competition and in different sports, it is critical to develop an accurate method for quantifying the effects of head impacts and determining the efficacy of helmets. This study examines the derivation of different dimensionless numbers and ascertains the critical factors needed to predict the effects of head impacts, specifically the resulting accelerations from an impact. Given a known force of impact, parameters such as peak translation …

Cartilage Engineering: Optimization Of Media For Chondrogenic Differentiation In Vitro, Evan Surma, Sherry L. Harbin, Hongji Zhang, Stacy Halum

The Summer Undergraduate Research Fellowship (SURF) Symposium

Lower back pain from intervertebral disc injury affects around 84% of the population at some point in their life, which at its worst may cause total immobilization. This pain can only be temporarily relieved by spinal fusion or intervertebral disc replacement; however, both of these cause loss of natural motion in patients by removing damaged fibrocartilage discs. While these techniques help mitigate pain briefly, no permanent solution exists currently to both relieve pain and preserve natural motion. My work may be a solution by eventually providing patient-specific implants that resemble native tissue in the regeneration process that could be absorbed …

Ball Pressure Correlations With Peak Impact Force And The Potential For Cumulative Mtbi When Heading A Soccer Ball, Nicolas Leiva, Daniel Y. Shyu, Josh Auger, Eric Nauman

The Summer Undergraduate Research Fellowship (SURF) Symposium

Soccer is a unique sport in which athletes use their heads as tools for gameplay, which may ultimately cause cumulative traumatic brain injuries. Due to rising popularity of soccer in the United States alongside the increased occurrence of CTE and mTBI in other contact sports, there is a growing concern over how to keep the repetitive forces caused by heading, as low as possible. Different variables that can affect the peak force felt when heading a soccer ball can be simulated and compared with in-game data, however, this has never been properly tested before. In the present study two size …

Nanobubbles Provide Theranostic Relief To Cancer Hypoxia, Christopher M. Long, Pushpak N. Bhandari, Joseph Irudayaraj

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hypoxia is a common motif among tumors, contributing to metastasis, angiogenesis, cellular epigenetic abnormality, and resistance to cancer therapy. Hypoxia also plays a pivotal role in oncological studies, where it can be used as a principal target for new anti-cancer therapeutic methods. Oxygen nanobubbles were designed in an effort to target the hypoxic tumor regions, thus interrupting the hypoxia-inducible factor-1α (HIF-1α) regulatory pathway and inhibiting tumor progression. At less than 100nm, oxygen nanobubbles act as a vehicle for site-specific oxygen delivery, while also serving as an ultrasound contrast agent for advanced imaging purposes. Through in vitro and in vivo studies, …