Biomedical Engineering and Bioengineering Commons^™

Under-Sampled Reconstruction Techniques For Accelerated Magnetic Resonance Imaging, Mohammad H. Kayvanrad

Electronic Thesis and Dissertation Repository

Due to physical and biological constraints and requirements on the minimum resolution and SNR, the acquisition time is relatively long in magnetic resonance imaging (MRI). Consequently, a limited number of pulse sequences can be run in a clinical MRI session because of constraints on the total acquisition time due to patient comfort and cost considerations. Therefore, it is strongly desired to reduce the acquisition time without compromising the reconstruction quality. This thesis concerns under-sampled reconstruction techniques for acceleration of MRI acquisitions, i.e., parallel imaging and compressed sensing.

While compressed sensing MRI reconstructions are commonly regularized by penalizing the decimated wavelet …

Interactions Of Peptide Triazole Thiols With Env Gp120 Induce Irreversible Breakdown And Inactivation Of Hiv-1 Virions, Arangassery Bastian, Mark Contarino, Lauren D. Bailey, Rachna Aneja, Diogo Rodrigo Magalhaes Moreira, Kevin Freedman, Karyn Mcfadden, Caitlin Duffy, Ali Emileh

Dartmouth Scholarship

Background: We examined the underlying mechanism of action of the peptide triazole thiol, KR13 that has been shown previously to specifically bind gp120, block cell receptor site interactions and potently inhibit HIV-1 infectivity.

Results: KR13, the sulfhydryl blocked KR13b and its parent non-sulfhydryl peptide triazole, HNG156, induced gp120 shedding but only KR13 induced p24 capsid protein release. The resulting virion post virolysis had an altered morphology, contained no gp120, but retained gp41 that bound to neutralizing gp41 antibodies. Remarkably, HIV-1 p24 release by KR13 was inhibited by enfuvirtide, which blocks formation of the gp41 6-helix bundle during membrane fusion, while …

The Development Of A New Dry Powder Inhaler, Xi Zhang

Electronic Thesis and Dissertation Repository

A new dry powder inhaler (DPI) for respiratory drug delivery was developed. This novel device is characterized by a micro-dose, passive delivery and multiple doses individually sealed in one replaceable disk. The micro-dose delivery system uses only a small amount of excipient, such as 2-3mg lactose, thereby improving the drug delivery efficiency. The passive delivery method eliminates the need for coordination between breath and device actuation such as the pressure metered dose inhaler (pMDI). Finally, 14 doses on a disk reduce the need to frequently change dosage disks. In addition, each dose is effectively protected by a blister package to …

Patient-Oriented Evidence-Based Treatment Decision Support System (Treatquest®) For Lung Cancer, Danqing Hu

Theses and Dissertations

Involving patients in healthcare decisions makes a significant and enduring difference to healthcare outcomes. One challenge for patients is the lack of evidence-based information and tools to support their decision making. Although patients have access to significant information through internet and other sources, it is not personalized for their specific situation. This dissertation attempts to help patients acquire evidence-based information relevant to their own situation, so they can make a more informed decision in co-operation with their physicians. Lung cancer has been selected as a focus for this study because lung cancer presents very complex decision making situation and is …

Electrotransfer Of Single-Stranded Or Double-Stranded Dna Induces Complete Regression Of Palpable B16.F10 Mouse Melanomas, Loree Heller, Vesba Todorovic, Maja Cemazar

Bioelectrics Publications

Enhanced tumor delivery of plasmid DNA with electric pulses in vivo has been confirmed in many preclinical models. Intratumor electrotransfer of plasmids encoding therapeutic molecules has reached Phase II clinical trials. In multiple preclinical studies, a reduction in tumor growth, increased survival or complete tumor regression have been observed in control groups in which vector or backbone plasmid DNA electrotransfer was performed. This study explores factors that could produce this antitumor effect. The specific electrotransfer pulse protocol employed significantly potentiated the regression. Tumor regression was observed after delivery of single-stranded or double-stranded DNA with or without CpG motifs in both …

Layered Long Term Co-Culture Of Hepatocytes And Endothelial Cells On A Transwell Membrane: Toward Engineering The Liver Sinusoid, Young Bok (Abraham) Kang, Siddhartha Rawat, Joseph Cirillo, Michael Bouchard, Hongseok (Moses) Noh

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

This paper presents a novel liver model that mimics the liver sinusoid where most liver activities occur. A key aspect of our current liver model is a layered co-culture of primary rat hepatocytes (PRHs) and primary rat liver sinusoidal endothelial cells (LSECs) or bovine aortic endothelial cells (BAECs) on a transwell membrane. When a layered co-culture was attempted with a thin matrigel layer placed between hepatocytes and endothelial cells to mimic the Space of Disse, the cells did not form completely separated monolayers. However, when hepatocytes and endothelial cells were cultured on the opposite sides of a transwell membrane, PRHs …

Formulation Development Of A Polymer-Drug Matrix With A Controlled Release Profile For The Treatment Of Glaucoma, Eric W. Tsoi

Master's Theses

Glaucoma is the leading cause of blindness in the United States accounting for 9-12% of all cases of blindness. Currently, the front line treatment for glaucoma are prostaglandins that may have to be taken up to several times a day. Even with proper treatment, roughly 11% of the patients using the treatment are non-compliant and lose their vision. In this project, ForSight Laboratories has developed a pharmaceutical drug delivering implant with the capability of sustaining long-term release of a prostaglandin as a new way to treat the condition. This project reports the product development of a polymer drug matrix with …

Functional 3-D Cellulose & Nitrocellulose Paper-Based, Multiplex Diagnostic Platforms Without Coupling Agents, Mackenzie Elizabeth Tageson

Master's Theses

The purpose of this thesis was to demonstrate device functionality of 3-D paper-based, multiplex platforms, µPADs, without the use of coupling agents between layers. Previously, these platforms were fabricated with double-sided tape and cellulose powder to try to augment proper fluid routing, but difficulties with this method occurred. An acrylic housing unit with strategically placed pressure tabs was designed to aid horizontal and vertical fluid routing through the platform, thus eliminating the inconsistencies associated with coupling agents. Channel characterization studies, a COMSOL^TM simulation, and development time studies were performed to aid device design and demonstrate device functionality.

The implementation …

Dopaminergic Modulation Of Memory And Affective Processing In Parkinson Depression, Lee X. Blonder, John T. Slevin, Richard J. Kryscio, Catherine A. Martin, Anders H. Andersen, Charles D Smith, Frederick A. Schmitt

Magnetic Resonance Imaging and Spectroscopy Center Faculty Publications

Depression is common in Parkinson's disease and is associated with cognitive impairment. Dopaminergic medications are effective in treating the motor symptoms of Parkinson's disease; however, little is known regarding the effects of dopaminergic pharmacotherapy on cognitive function in depressed Parkinson patients. This study examines the neuropsychological effects of dopaminergic pharmacotherapy in Parkinsonian depression. We compared cognitive function in depressed and non-depressed Parkinson patients at two time-points: following overnight withdrawal and after the usual morning regimen of dopaminergic medications. A total of 28 non-demented, right-handed patients with mild to moderate idiopathic Parkinson's disease participated. Ten of these patients were depressed according …

A Novel Signal Processing Method For Intraoperative Neurophysiological Monitoring In Spinal Surgeries, Krishnatej Vedala

FIU Electronic Theses and Dissertations

Intraoperative neurophysiologic monitoring is an integral part of spinal surgeries and involves the recording of somatosensory evoked potentials (SSEP). However, clinical application of IONM still requires anywhere between 200 to 2000 trials to obtain an SSEP signal, which is excessive and introduces a significant delay during surgery to detect a possible neurological damage. The aim of this study is to develop a means to obtain the SSEP using a much less, twelve number of recordings. The preliminary step involved was to distinguish the SSEP with the ongoing brain activity. We first establish that the brain activity is indeed quasi-stationary whereas …

Direct Quantitative Analysis Of Biomarkers Using Mass Spectrometry, Morgan N. Mcluckey, Zheng Ouyang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Point-of-care (POC) diagnostics describes a step in the medical treatment process where drugs can be monitored in a patient’s body on-site and in a timely fashion. Mass spectrometry (MS) can provide a quick, efficient, and highly accurate method of analysis of patient biofluids and tissues. Developing methods to bring this diagnostic mechanism to hospitals and clinics has the potential to improve patient care through, for example, personalized medicine. Our goal was to develop a way to effectively introduce internal standard (IS), a necessary chemical for the analytical process, to low-volume biofluid samples. Additionally, the effective direct quantitation of biomarkers with …

Changes In Hemodynamic Responses In Chronic Stroke Survivors Do Not Affect Fmri Signal Detection In A Block Experimental Design, Nutta-On Promjunyakul, Brian D. Schmit, Sheila Schindler-Ivens

Physical Therapy Faculty Research and Publications

The use of canonical functions to model BOLD-fMRI data in people post-stroke may lead to inaccurate descriptions of task-related brain activity. The purpose of this study was to determine whether the spatiotemporal profile of hemodynamic responses (HDRs) obtained from stroke survivors during an event-related experiment could be used to develop individualized HDR functions that would enhance BOLD-fMRI signal detection in block experiments. Our long term goal was to use this information to develop individualized HDR functions for stroke survivors that could be used to analyze brain activity associated with locomotor-like movements. We also aimed to examine the reproducibility of HDRs …

Development And Assessment Of An Impact Apparatus And High-Speed Camera Motion Tracking System To Quantify The Effect Of Static Muscle Loads On Fracture Threshold Measures In The Distal Radius, Jacob M. Reeves

Electronic Thesis and Dissertation Repository

Distal radius fractures are prevalent, debilitating, and costly. This thesis conducts an in vitro investigation of these injuries, examining the role of static muscle loading on fracture threshold measures (i.e., force, impulse, energy). Initially, an impact apparatus and custom LabVIEW colour-thresholding program were designed and assessed for repeatability and accuracy in quantifying fracture measures and impact kinematics. These tools were then used to test six pairs of cadaveric forearms, with static muscle loads simulated in one specimen from each pair. Distal radius fractures were achieved in 5 pairs, with perilunate dislocations in the remaining pair. None of the …

Design And Development Of A Novel Expanding Pedicle Screw For Use In The Osteoporotic Lumbar Spine, Parham Rasoulinejad

Electronic Thesis and Dissertation Repository

Pedicle screws are commonly utilized in spinal surgery; however, traditional designs often do not provide adequate fixation in osteoporotic spines. The objective of this thesis was to develop a novel expanding screw for use in osteoporotic lumbar pedicles. Helical screws capable of expanding post insertion were built on a rapid prototype machine. A materials testing machine performed axial load to failure tests in both Sawbones and cadaveric specimens comparing the new design to traditional screws (rate = 10mm/min to 20 mm). Output parameters included yield load, ultimate load, stiffness, energy to failure and total energy. The expanding screw showed a …

Spectral Discrimination Of Breast Pathologies In Situ Using Spatial Frequency Domain Imaging, Ashley M. Laughney, Venkataramanan Krishnaswamy, Elizabeth J. Rizzo, Mary C. Schwab, Richard J. Barth, David J. Cuccia, Bruce J. Tromberg, Keith D. Paulsen, Brian W. Pogue, Wendy A. Wells

Dartmouth Scholarship

Introduction: Nationally, 25% to 50% of patients undergoing lumpectomy for local management of breast cancer require a secondary excision because of the persistence of residual tumor. Intraoperative assessment of specimen margins by frozen-section analysis is not widely adopted in breast-conserving surgery. Here, a new approach to wide-field optical imaging of breast pathology in situ was tested to determine whether the system could accurately discriminate cancer from benign tissues before routine pathological processing.

Interleukin Expression After Injury And The Effects Of Interleukin-1 Receptor Antagonist, Connie S. Chamberlain, Ellen M. Leiferman, Kayt E. Frisch, Stacey L. Brickson, William L. Murphy, Geoffrey S. Baer

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Ligament and tendon repair involves a complex series of coordinated events orchestrated by various cell types, cytokines and other factors. The repair process extends months to years and results in scar tissue mechanically inferior to native tissue. This is in clear contrast to tissue "regeneration" which would recapitulate the native tissue. Numerous approaches to stimulate a regenerative scenario have been attempted, including tissue-engineering, non-steroidal anti-inflammatories, ultrasonic, or electrical stimulation, but none have resulted in complete regeneration. In pursuit of a more regenerative outcome, it is important to understand the fundamentals of the normal healing process. Previous work from our lab …

Polysaccharide-Based Nanocarriers For Improved Drug Delivery, Nan Zhang

Dissertations - ALL

The field of drug delivery has provided a solution to the limited efficacy and high toxicity of many drugs. Nano-sized drug carriers are popular because their size allows for selective accumulation in the diseased area. Polysaccharides are non-toxic and biodegradable natural polymers that can serve as the basis for these nano-sized carriers. Polysialic acid (PSA) is such a polysaccharide with strong hydrophilicity that may reduce uptake by the reticuloendothelial system and prolong drug circulation. In this study, we developed PSA-based nanocarriers, specifically micelles and nanoparticles, for improved drug delivery with improved efficacy and minimized toxicity. PSA-based micelle systems were developed …

Hybrid Nanostructured Textile Bioelectrode For Unobtrusive Health Monitoring, Pratyush Rai

Graduate Theses and Dissertations

Coronary heart disease, cardiovascular diseases and strokes are the leading causes of mortality in United States of America. Timely point-of-care health diagnostics and therapeutics for person suffering from these diseases can save thousands of lives. However, lack of accessible minimally intrusive health monitoring systems makes timely diagnosis difficult and sometimes impossible. To remedy this problem, a textile based nano-bio-sensor was developed and evaluated in this research. The sensor was made of novel array of vertically standing nanostructures that are conductive nano-fibers projecting from a conductive fabric. These sensor electrodes were tested for the quality of electrical contact that they made …

Efferent Copy And Corollary Discharge Motor Control Behavior Associated With A Hopping Activity, Wangdo Kim, António P. Veloso, Filipa João, Sean S. Kohles

Mechanical and Materials Engineering Faculty Publications and Presentations

Hoppers respond not only to stimuli from the ground surfaces but also to cues generated by their own behaviors. This leads to desensitization because although the afferent and reafferent signals have distinct causes, they are carried by the same sensory channels. From a behavioral viewpoint, it may be necessary to distinguish between signals from the two causes especially when monitoring changes in the external environment separate from those due to self-movement. We were able to separate afferent sensory stimuli from self-generated, reafferent signals using an action oriented perception system and dynamic programming approach. This effort addressed the question of how …

An Assessment Of Novel Biodegradable Magnesium Alloys For Endovascular Biomaterial Applications, Dharam Persaud-Sharma

FIU Electronic Theses and Dissertations

Magnesium alloys have been widely explored as potential biomaterials, but several limitations to using these materials have prevented their widespread use, such as uncontrollable degradation kinetics which alter their mechanical properties. In an attempt to further the applicability of magnesium and its alloys for biomedical purposes, two novel magnesium alloys Mg-Zn-Cu and Mg-Zn-Se were developed with the expectation of improving upon the unfavorable qualities shown by similar magnesium based materials that have previously been explored. The overall performance of these novel magnesium alloys has been assessesed in three distinct phases of research: 1) analysing the mechanical properties of the as-cast …

Beach Wheelchair Project, Rory Aronson, Joshua Marcum, Samuel Coyne, Alex Hayes, Alexa Colburn, Max Hessel, Benedikt Strauss, Marvin Rimmele, Marco Pietsch

Mechanical Engineering

The Beach Wheelchair, Sandcrawler, is a machine intended to help give people with disabilities the full beach experience. The non-profit organization Bridge II Sports sponsored this project, and tasked us with developing the design and fabricating a prototype. This chair has several features including a linkage mechanism that raises and lowers a chair relative to an external frame, hand crank drive with Gates Carbondrive belt and sprockets, buoyant Wheeleez balloon tires, and much more.

Fluorescence Characterization Of Quantum Dots For Use As Biomarkers, Logan M. Grimes

Materials Engineering

Fluorescence profiles of quantum dots (QDs) were characterized to select the ideal QDs for encapsulation in phospholipids for use as biomarkers to selectively adhere to cancer cells. QDs were synthesized and extracted 0, 30, 60, and 90 seconds after precursor compounds were mixed. These extractions were isolated by extraction time. Portions from each vial were coated in a zinc sulfide shelling procedure, leaving at least half of the QD solution unshelled. These samples were characterized over four days to monitor fluctuations in fluorescence. This was done utilizing an Ocean Optics spectrometer in conjunction with Spectra Suite software. The central wavelength, …

Studying The Material Properties Of The Embryonic Chicken Heart, Kyra Burnett

Honors Theses

Congenital heart disease is the number one cause of birth defects in the United States, affecting approximately 40,000 newborns each year. Research has shown that serious structural defects of the heart can occur due to abnormal looping. Looping refers to the positional and morphological changes of the early embryo heart and is divided into different phases. Although progress has been made in identifying the genetic processes behind heart looping, the forces involved with the developmental process are still not fully understood. In this research, the chicken embryo heart was used as the experimental model and certain material properties were characterized. …

History Of Concussion Research In American Football, Timothy Hersey

Honors Theses

Concussions have been the topic of discussion in the news and media in recent years for their profound impact on today’s sport industry. Athletes have become bigger, faster, and stronger then in the past, increasing the chance of injury. This can been seen in all sports. Contact sports specifically have seen a rise in mild traumatic brain injuries (MTBIs) over the years. Extensive research has been done to determine the causes of concussion, the short and long term effects of brain injury, and better ways to reduce the risk in sports. Concussion research in athletics has mainly focused on American …

Evaluation Of The Anterior Talofibular And Calcaneofibular Ligament In Relation To Supination Ankle Sprains, Peter Tran

Biomedical Engineering

Ankle injuries have always posed an issue to a number of athletes. Sports that involve running and jumping accumulate about 25% of injuries correlating to ankle sprains. In most ankle sprains the inversion (supination) of the ankle cause damage to lateral ligaments. The two most common lateral ligaments to experience damage are the anterior talofibular (ATFL) and calcaneofibular (CFL) ligaments. The methods of taping and ankle braces have allowed athletes to prevent recurring sprains from occurring. However, sprains can still occur even when one or both methods are applied. The purpose of each method is to restrict the range of …

Dynamic Dual-Tracer Mri-Guided Fluorescence Tomography To Quantify Receptor Density In Vivo, Scott C. Davis, Kimberley S. Samkoe, Kenneth M. Tichauer, Kristian J. Sexton, Jason R. Gunn, Sophie J. Deharvengt, Tayyaba Hasan, Brian W. Pogue

Dartmouth Scholarship

The up-regulation of cell surface receptors has become a central focus in personalized cancer treatment; however, because of the complex nature of contrast agent pharmacokinetics in tumor tissue, methods to quantify receptor binding in vivo remain elusive. Here, we present a dual-tracer optical technique for noninvasive estimation of specific receptor binding in cancer. A multispectral MRI-coupled fluorescence molecular tomography system was used to image the uptake kinetics of two fluorescent tracers injected simultaneously, one tracer targeted to the receptor of interest and the other tracer a nontargeted reference. These dynamic tracer data were then fit to a dual-tracer compartmental model …

Biomedical Photoacoustic Imaging Using Gas-Coupled Laser Acoustic Detection, Jami Johnson

Student Research Initiative

Several detection methods have been explored for photoacoustic and ultrasound imaging of biological tissues. Piezoelectric transducers are commonly used, which require contact with the sample to be imaged and have limiting bandwidth characteristics. Interferometry detection exhibits improved bandwidth characteristics and resolution, yet generally require complicated optics and the incorporation of a contacting reflective medium. In this paper, we report the use of a noncontact photoacoustic imaging system that does not require the use of a reflective layer. A simple, robust technique known as gas-coupled laser acoustic detection is used, which has previously been applied to evaluation of composite materials. This …

Automated Home Apnea System, Collin G. Howser, Trevor Grieco

Chancellor’s Honors Program Projects

No abstract provided.

Delayed Thrombus Resolution And Fibroproliferative Vascular Wound Healing From Deficiency Of Type Iii Collagen: A Paradoxical Mechanism For Tissue Fragility, Amy J. Reid

Dissertations & Theses (Open Access)

Vascular Ehlers-Danlos syndrome is a heritable disease of connective tissue caused by mutations in COL3A1, conferring a tissue deficiency of type III collagen. Cutaneous wounds heal poorly in these patients, and they are susceptible to spontaneous and catastrophic rupture of expansible hollow organs like the gut, uterus, and medium-sized to large arteries, which leads to premature death. Although the predisposition for organ rupture is often attributed to inherent tissue fragility, investigation of arteries from a haploinsufficient Col3a1 mouse model (Col3a1^+/-) demonstrates that mutant arteries withstand even supraphysiologic pressures comparably to wild-type vessels. We hypothesize that injury …

Design And Testing Of Novel Mouthguard With Intermediate Nitinol And Foam Layers, Adam Kessler

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is the aim of this study to investigate a novel mouthguard design that incorporates the use of a nickel-titanium (Nitinol) layer and thin foam layer in addition to EVA layers. It is thought that the Nitinol layer can distribute the force of an impact and that the thin foam layer may absorb this distributed force better than a solid EVA mouthguard of the same thickness. Rectangular, flat coupons representative of several mouthguard configurations were constructed for testing using an instrumented drop-weight impact tower. The coupon configurations include a control made of laminated EVA, a group of laminated EVA and …