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Biomedical Engineering and Bioengineering Commons

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2013

Theses and Dissertations

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Articles 1 - 30 of 54

Full-Text Articles in Biomedical Engineering and Bioengineering

The Design And Validation Of A Computational Rigid Body Model For Study Of The Radial Head, Cassandra Woodcock Dec 2013

The Design And Validation Of A Computational Rigid Body Model For Study Of The Radial Head, Cassandra Woodcock

Theses and Dissertations

Rigid body modeling has historically been used to study various features of the elbow joint including both physical and computational models. Computational modeling provides an inexpensive, easily customizable, and effective method by which to predict and investigate the response of a physiological system to in vivo stresses and applied perturbations. Utilizing computer topography scans of a cadaveric elbow, a virtual representation of the joint was created using the commercially available MIMICS(TM) and SolidWorks(TM) software packages. Accurate 3D articular surfaces, ligamentous constraints, and joint contact parameters dictated motion. The model was validated against two cadaveric studies performed by Chanlalit ...


Localization Of Auditory Spatial Targets In Sighted And Blind Subjects, Richard Nuckols Dec 2013

Localization Of Auditory Spatial Targets In Sighted And Blind Subjects, Richard Nuckols

Theses and Dissertations

This research was designed to investigate the fundamental nature in which blind people utilize audible cues to attend to their surroundings. Knowledge on how blind people respond to external spatial stimuli is expected to assist in development of better tools for helping people with visual disabilities navigate their environment. There was also interest in determining how blind people compare to sighted people in auditory localization tasks. The ability of sighted individuals, blindfolded individuals, and blind individuals in localizing spatial auditory targets was assessed. An acoustic display board allowed the researcher to provide multiple sound presentations to the subjects. The subjects ...


Examination Of The Effect Of Different Training Metrics On Performance Of A Minimally Invasive Surgery Transfer Task, Cristofer Madera Dec 2013

Examination Of The Effect Of Different Training Metrics On Performance Of A Minimally Invasive Surgery Transfer Task, Cristofer Madera

Theses and Dissertations

The purpose of this experiment was to determine if there existed techniques to more efficiently train prospective surgeons the skills necessary to capably perform minimally invasive surgical procedures. Also, we wanted to know if trainees could be pushed to cognitively define a laparoscopic environment with a novel hand-eye relationship. To explore these questions, a simulation was setup wherein subjects would perform a laparoscopic transfer task and receive active feedback during training. Different subjects would receive different metrics as feedback and a comparison would be made between subjects with respect to standard metrics. Results of this experiment show that all subjects ...


Patient-Specific Modeling Of Adult Acquired Flatfoot Deformity Before And After Surgery, Edward Meade Spratley Dec 2013

Patient-Specific Modeling Of Adult Acquired Flatfoot Deformity Before And After Surgery, Edward Meade Spratley

Theses and Dissertations

The use of computational modeling is an increasingly commonplace technique for the investigation of biomechanics in intact and pathological musculoskeletal systems. Moreover, given the robust and repeatable nature of computer simulation and the prevalence of software techniques for accurate 3-D reconstructions of tissues, the predictive power of these models has increased dramatically. However, there are no patient-specific kinematic models whose function is dictated solely by physiologic soft-tissue constraints, articular shape and contact, and without idealized joint approximations. Moreover, very few models have attempted to predict surgical effects combined with postoperative validation of those predictions. Given this, it is not surprising ...


Patient-Oriented Evidence-Based Treatment Decision Support System (Treatquest®) For Lung Cancer, Danqing Hu Dec 2013

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 ...


Extraction And Classification Of Drug-Drug Interaction From Biomedical Text Using A Two-Stage Classifier, Majid Rastegar-Mojarad Dec 2013

Extraction And Classification Of Drug-Drug Interaction From Biomedical Text Using A Two-Stage Classifier, Majid Rastegar-Mojarad

Theses and Dissertations

One of the critical causes of medical errors is Drug-Drug interaction (DDI), which occurs when one drug increases or decreases the effect of another drug. We propose a machine learning system to extract and classify drug-drug interactions from the biomedical literature, using the annotated corpus from the DDIExtraction-2013 shared task challenge. Our approach applies a two-stage classifier to handle the highly unbalanced class distribution in the corpus. The first stage is designed for binary classification of drug pairs as interacting or non-interacting, and the second stage for further classification of interacting pairs into one of four interacting types: advise, effect ...


Angiography And Monitoring Of Hemodynamic Signals In The Brain Via Optical Coherence Tomography, Alana Mauluidy Soehartono Dec 2013

Angiography And Monitoring Of Hemodynamic Signals In The Brain Via Optical Coherence Tomography, Alana Mauluidy Soehartono

Theses and Dissertations

The brain is a complex network of interconnected neurons with each cell functioning as a nonlinear processing unit. Neural responses to stimulus can be described by activity in neurons. While blood flow changes have been associated with neural activity and are critical to brain function, this neurovascular coupling is not well understood. This work presents a technique for neurovascular interrogation, combining optogenetics and optical coherence tomography.

Optogenetics is a recently developed neuromodulation technique to control activity in the brain using light with precise spatial neuronal control and high temporal resolution. Using this method, cells act as light-gated ion channels and ...


Extracting The Structure And Conformations Of Biological Entities From Large Datasets, Ali Dashti Dec 2013

Extracting The Structure And Conformations Of Biological Entities From Large Datasets, Ali Dashti

Theses and Dissertations

In biology, structure determines function, which often proceeds via changes in conformation. Efficient means for determining structure exist, but mapping conformations continue to present a serious challenge. Single-particles approaches, such as cryogenic electron microscopy (cryo-EM) and emerging "diffract & destroy" X-ray techniques are, in principle, ideally positioned to overcome these challenges. But the algorithmic ability to extract information from large heterogeneous datasets consisting of "unsorted" snapshots - each emanating from an unknown orientation of an object in an unknown conformation - remains elusive.

It is the objective of this thesis to describe and validate a powerful suite of manifold-based algorithms able to extract ...


Cuda K-Nn: Application To The Segmentation Of The Retinal Vasculature Within Sd-Oct Volumes Of Mice, Wenxiang Deng Dec 2013

Cuda K-Nn: Application To The Segmentation Of The Retinal Vasculature Within Sd-Oct Volumes Of Mice, Wenxiang Deng

Theses and Dissertations

No abstract provided.


Novel Adaptive Reconstruction Schemes For Accelerated Myocardial Perfusion Magnetic Resonance Imaging, Sajan Goud Lingala Dec 2013

Novel Adaptive Reconstruction Schemes For Accelerated Myocardial Perfusion Magnetic Resonance Imaging, Sajan Goud Lingala

Theses and Dissertations

Coronary artery disease (CAD) is one of the leading causes of death in the world. In the United States alone, it is estimated that approximately every 25 seconds, a new CAD event will occur, and approximately every minute, someone will die of one. The detection of CAD during in its early stages is very critical to reduce the mortality rates. Magnetic resonance imaging of myocardial perfusion (MR-MPI) has been receiving significant attention over the last decade due to its ability to provide a unique view of the microcirculation blood flow in the myocardial tissue through the coronary vascular network. The ...


Modeling Of The Human Larynx With Application To The Influence Of False Vocal Folds On The Glottal Flow, Mehrdad Hosnieh Farahani Dec 2013

Modeling Of The Human Larynx With Application To The Influence Of False Vocal Folds On The Glottal Flow, Mehrdad Hosnieh Farahani

Theses and Dissertations

Human phonation is a complex phenomenon produced by multiphysics interaction of the fluid, tissue and acoustics fields. Despite recent advancement, little is known about the effect of false vocal folds on the fluid dynamics of the glottal flow. Recent investigations have hypothesized that this pair of tissue can affect the laryngeal flow during phonation. This hypothesis was tested both computationally and experimentally in this dissertation. The computations were performed using an incompressible solver developed in fixed Cartesian grid with a second order sharp immersed-boundary formulation while the experiments were carried out in a low-speed wind tunnel with physiologic speeds and ...


Machine-Learning Based Automated Segmentation Tool Development For Large-Scale Multicenter Mri Data Analysis, Eun Young Kim Dec 2013

Machine-Learning Based Automated Segmentation Tool Development For Large-Scale Multicenter Mri Data Analysis, Eun Young Kim

Theses and Dissertations

Background: Volumetric analysis of brain structures from structural Mag- netic Resonance (MR) images advances the understanding of the brain by providing means to study brain morphometric changes quantitatively along aging, development, and disease status. Due to the recent increased emphasis on large-scale multicenter brain MR study design, the demand for an automated brain MRI processing tool has increased as well. This dissertation describes an automatic segmentation framework for subcortical structures of brain MRI that is robust for a wide variety of MR data.

Method: The proposed segmentation framework, BRAINSCut, is an inte- gration of robust data standardization techniques and machine-learning ...


The Development Of A Traumatic Brain Injury Bioreactor, Zachery Heller Dec 2013

The Development Of A Traumatic Brain Injury Bioreactor, Zachery Heller

Theses and Dissertations

Approximately 1.7 million Americans experience a traumatic brain injury (TBI) each year. Concussive injuries are a subset of TBI in which blows to the head cause the brain to collide against the interior of the skull. Damage to the neurons, supporting cells, and surrounding extra cellular matrix resulting from these collisions can lead to permanent physical, cognitive, and psychological impairment. We believe the prevalence and clinical significance of concussive injures warrants research investment. To study brain injury following TBI, in vivo models have been the gold standard for TBI experiments. Although a valuable research alternative, animals are expensive, raise ...


Spectral Analysis Of Nonstationary Heart Rate Of Neonates Receiving Therapeutic Hypothermia Treatment, Tareq Al-Shargabi Nov 2013

Spectral Analysis Of Nonstationary Heart Rate Of Neonates Receiving Therapeutic Hypothermia Treatment, Tareq Al-Shargabi

Theses and Dissertations

We studied Heart Rate Variability (HRV) evolution during therapeutic hypothermia in newborns with hypoxic ischemic encephalopathy (HIE) using spectral analysis. We hypothesized that HRV measures are predictive of neurological outcome in babies with HIE. Non-stationarity in the data causes inaccurate quantification of the spectral power. A modification was proposed to power spectral analysis approach to mitigate the effect of non-stationarity. The modified and the standard approaches were applied to cardiac beat-to-beat intervals of newborns receiving hypothermia treatment. The performance of the approaches in distinguishing the RRi dynamics of two groups of newborns was assessed using area under the receiver operating ...


The Design And Development Of A Perceptual-Based Haptic Display Device, Sohaib Akhter Aug 2013

The Design And Development Of A Perceptual-Based Haptic Display Device, Sohaib Akhter

Theses and Dissertations

Graphical information presented as pictures, graphs, maps, and the like are an important media for relaying knowledge and are a fundamental means of education rarely experienced by people who are blind or have a severe visual impairment. This thesis presents the design, development and testing of a multiple finger, haptic matrix dynamic display device capable of relaying graphical information through simulated textures. The design is based on user perception studies that determined which hand constraints provided the best tradeoff between simplicity of design, accuracy and time to answer. The best design was one that incorporated multiple fingers in close proximity ...


Continuum Deformation Model For Drug-Eluting Stent (Des) Medical Devices Using Finite Element Analysis (Fea), Solki Lee Aug 2013

Continuum Deformation Model For Drug-Eluting Stent (Des) Medical Devices Using Finite Element Analysis (Fea), Solki Lee

Theses and Dissertations

The development of coronary stent medical devices was originally considered as a major advance in the treatment of obstructive cardiovascular disease. The implantation of stent, however, involves clinical adverse effects such as re-narrowing of arterial wall after stenting. Drug-eluting stents (DES) have been developed to prevent such adverse effects by slowly delivering anti-proliferative and/or anti-inflammatory drugs from coating composites of drug-containing polymers. One of the major issues in DES implantation is, however, that the coatings comprised of drug and polymer composite phases are often fractured or delaminated during the deployment of stent, which can lead to more serious clinical ...


Fibrinogen-Conjugated Gold-Coated Magnetite Nanoparticles For Antiplatelet Therapy, Evan Schuerer Krystofiak Aug 2013

Fibrinogen-Conjugated Gold-Coated Magnetite Nanoparticles For Antiplatelet Therapy, Evan Schuerer Krystofiak

Theses and Dissertations

Ischemic stroke is the world's second leading cause of death and accounts for 2-4% of total worldwide healthcare costs. Ischemic stroke is caused by the occlusion of arteries responsible for supplying blood to the brain, which can result in disability or death. Arterial blood clots consist of aggregates of activated platelets wrapped in a mesh of fibrin. Tissue plasminogen activator, the only current FDA-approved treatment for ischemic stroke, functions by lysing fibrin in a blood clot. Unfortunately, tissue plasminogen activator significantly increases bleeding risks, which restricts its use. Alternatively, targeting and disrupting platelets within a clot could improve stroke ...


Density Functional Theory (Dft) Study On The Hydrolysis Behavior Of Degradable Mg/Mg Alloys For Biomedical Applications, Marjan Nezafati Aug 2013

Density Functional Theory (Dft) Study On The Hydrolysis Behavior Of Degradable Mg/Mg Alloys For Biomedical Applications, Marjan Nezafati

Theses and Dissertations

Magnesium-based (Mg and/or Mg alloys) materials possess many advantageous physicochemical/biological characteristics such as good biocompatibility and similarity of the mechanical properties to the human bone tissue, which renders this material a promising candidate for the biomedical and implant applications. One of the most attractive features of Mg-based materials is the degradability in the physiological environment. With the burst of research on the biodegradable materials for the healthcare device applications, Mg and its alloys attracted a strong attention in the bioengineering field in recent years. However, the major limitation of applying Mg-based materials to biomedical applications is the fast ...


Efficient Computation Of K-Nearest Neighbor Graphs For Large High-Dimensional Data Sets On Gpu Clusters, Ali Dashti Aug 2013

Efficient Computation Of K-Nearest Neighbor Graphs For Large High-Dimensional Data Sets On Gpu Clusters, Ali Dashti

Theses and Dissertations

The k-Nearest Neighbor Graph (k-NNG) and the related k-Nearest Neighbor (k-NN) methods have a wide variety of applications in areas such as bioinformatics, machine learning, data mining, clustering analysis, and pattern recognition. Our application of interest is manifold embedding. Due to the large dimensionality of the input data (<15k), spatial subdivision based techniques such OBBs, k-d tree, BSP etc., are not viable. The only alternative is the brute-force search, which has two distinct parts. The first finds distances between individual vectors in the corpus based on a pre-defined metric. Given the distance matrix, the second step selects k nearest neighbors for each member of the query data set.

This thesis presents the development and implementation of a distributed exact k-Nearest Neighbor Graph (k-NNG) construction method. The proposed method uses Graphics Processing Units (GPUs) and exploits multiple levels of parallelism for distributed computational systems using GPUs. It is scalable for different cluster sizes, with each compute node in the cluster containing ...


Hybrid Nanostructured Textile Bioelectrode For Unobtrusive Health Monitoring, Pratyush Rai Aug 2013

Hybrid Nanostructured Textile Bioelectrode For Unobtrusive Health Monitoring, Pratyush Rai

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 ...


The Effect Of Concurrent Cognitive-Visuomotor Multitasking And Task Difficulty On Dynamic Functional Connectivity In The Brain, Plamen Nikolov Jul 2013

The Effect Of Concurrent Cognitive-Visuomotor Multitasking And Task Difficulty On Dynamic Functional Connectivity In The Brain, Plamen Nikolov

Theses and Dissertations

This thesis investigated the effect of visuomotor and working memory 1) task difficulty and 2) multitasking on dynamic functional connectivity in the brain. Studies have only recently begun to investigate functional connectivity within the scope of concurrent dual task or varying task difficulty conditions (Cocchi, Zalesky, et al. 2011; Rietschel et al. 2012). A series of EEG recordings were conducted during execution of visuomotor or working memory tasks within a novel paradigm using BCI2VR custom MATLAB toolbox. Functional connectivity was correlated with task-related coherence (TRCoh) analysis between two task conditions involving either variation in task difficulty or concurrent execution during ...


Semi-Interpenetrating Network Gelatin Fiber Sca Old For Oral Mucosal Delivery Of Insulin, Leyuan Xu Jul 2013

Semi-Interpenetrating Network Gelatin Fiber Sca Old For Oral Mucosal Delivery Of Insulin, Leyuan Xu

Theses and Dissertations

Common therapy for diabetes mellitus is subcutaneous administration of insulin that is subject to serious disadvantages, such as patient noncompliance and occasional hypoglycemia. Hence, oral administration of insulin could be more convenient and serve as a desired route. However, oral administration of insulin is severely limited by the low bioavailability of insulin through the gastrointestinal tract. In this study, a semi-interpenetrating network gelatin fiber scaffold (sIPN GF) was fabricated for oral mucosal delivery of insulin as an alternative route. This sIPN GF was engineered from an electrospun gelatin fiber scaffold (GF), which was further crosslinked with polyethylene glycol diacrylate (PEG-DA ...


Incorporating Sheet-Likeness Information In Intensity-Based Lung Ct Image Registration, Yang Wook Kim Jul 2013

Incorporating Sheet-Likeness Information In Intensity-Based Lung Ct Image Registration, Yang Wook Kim

Theses and Dissertations

Image registration is a useful technique to measure the change between two or more images. Lung CT image registration is widely used an non-invasive method to measure the lung function changes. Non-invasive lung function measurement accuracy highly depends on lung CT image registration accuracy. Improving the registration accuracy is an important issue.

In this thesis, we propose incorporating information of the anatomical structure of the lung (fissures) as an additional cost function of the lung CT image registration. The intensity-based similarity measurement method (sum of the squared tissue volume differences) is also used to complement lung tissue information matching. However ...


Heterogeneous Finite Element Stress Analysis Of Abdominal Aortic Aneurysms : Comparison Between Ruptured And Unruptured Lesions, Timothy Kwang-Joon Chung Jul 2013

Heterogeneous Finite Element Stress Analysis Of Abdominal Aortic Aneurysms : Comparison Between Ruptured And Unruptured Lesions, Timothy Kwang-Joon Chung

Theses and Dissertations

Abdominal Aortic Aneurysm (AAA) rupture remains a leading cause of death in westernized countries. Much remains to be understood on the biomechanics of rupture. It is not clear whether rupture is predominantly a phenomenon at the material level (aneurysm wall weakening) or due to abnormally elevated tissue wall tension (stress resultant). A computational study involving 4 ruptured and 9 unruptured abdominal aortic aneurysms (AAA) was conducted to test if ruptured aneurysms were subject to a higher pressure induced wall tension than unruptured aneurysms. The unique aspect of this study is that, regional variations in material properties (thickness, stiffness, failure strength ...


Clubfoot Image Classification, Amanda Marie De Hoedt Jul 2013

Clubfoot Image Classification, Amanda Marie De Hoedt

Theses and Dissertations

Clubfoot is a congenital foot disorder that, left untreated, can limit a person's mobility by making it difficult and painful to walk. Although inexpensive and reliable treatment exists, clubfoot often goes untreated in the developing world, where 80% of cases occur.

Many nonprofit and non-governmental organizations are partnering with hospitals and clinics in the developing world to provide treatment for patients with clubfoot, and to train medical personnel in the use of these treatment methods.

As a component of these partnerships, clinics and hospitals are collecting patient records. Some of this patient information, such as photographs, requires expert quality ...


Detecting Activity-Evoked Ph Changes In Human Brain, Hye Young Heo Jul 2013

Detecting Activity-Evoked Ph Changes In Human Brain, Hye Young Heo

Theses and Dissertations

Localized pH changes have been suggested to occur in the brain during normal function. However, a lack of methods for non-invasively measuring pH with high spatial and temporal resolution limits current knowledge of brain pH dynamics. Here I report that a magnetic resonance imaging (MRI) strategy named T1 relaxation in the rotating frame (T) is sufficiently sensitive to detect widespread pH changes in the mouse and human brain evoked by systemically manipulating carbon dioxide (CO2) or bicarbonate (HCO3). Moreover, T detected changes suggesting a localized acidosis in the human visual cortex induced by a flashing ...


Surgical Simulation Training Models For Orthopaedic Fracture Surgery, Gary Thomas Ohrt Jul 2013

Surgical Simulation Training Models For Orthopaedic Fracture Surgery, Gary Thomas Ohrt

Theses and Dissertations

Articular fracture reduction is a complex surgical task that requires surgeons to be competent at multiple surgical skills to successfully complete. The list of skills needed includes the ability to use fluoroscopic images to build a 3D mental model of the fracture during reconstruction, the proper handling and use of surgical instruments, how to manipulate the fracture fragment into a reduced configuration with minimal hand motion, proper k-wire placement, and the preservation of surrounding soft tissues. Current training methodology is based on an apprenticeship model. The resident learns by watching a senior surgeon, and then preforms the procedure on live ...


Development Of A Novel Balance Assessment Tool And Its Validation In The Study Of Patients With Symptomatic Spinal Deformity, Monica Paliwal Jul 2013

Development Of A Novel Balance Assessment Tool And Its Validation In The Study Of Patients With Symptomatic Spinal Deformity, Monica Paliwal

Theses and Dissertations

The prevalence of scoliosis in those over age 60 varies from 39%-68%. Common presenting symptoms include back pain, radiculopathy, and progressive deformity. Radiographic characteristics have been previously described that correlate with these symptoms including vertebral spondylolisthesis, endplate obliquity, lumbar hypolordosis, thoracolumbar junction kyphosis and positive sagittal balance. Nevertheless, asymptomatic volunteers present with similar spinal deformities. It is likely that other factors such as age, body habitus, and exercise capacity affect or outweigh the severity of radiographic parameters. The ability to maintain the center of gravity of the body within the cone of economy results from a combination of alignment ...


Discriminating Chondrogenic Progenitor Cells (Cpcs) As A Distinct Cell Type, Apart From Normal Chondrocytes, Cheng Zhou Jul 2013

Discriminating Chondrogenic Progenitor Cells (Cpcs) As A Distinct Cell Type, Apart From Normal Chondrocytes, Cheng Zhou

Theses and Dissertations

Articular cartilage is an avascular, aneural, and alymphatic tissue with a structure consisting of a superficial, a middle and a deep zone, overlie a calcified zone at the cartilage border between. Each zone has biological and mechanical properties. Self-repair of damaged cartilage seldom if ever occurs, and joint injuries that harm cartilage surfaces often result in osteoarthritis. This has prompted researchers to explore diverse approaches to cartilage regeneration.

The superficial zone shows the highest cellularity and the lowest matrix density. Cartilage cells (chondrocytes) residing in the superficial zone had been thought to be a subpopulation of chondrocytes. However, our laboratory ...


Automatic Segmentation Of Pressure Images Acquired In A Clinical Setting, Anathea Pepperl May 2013

Automatic Segmentation Of Pressure Images Acquired In A Clinical Setting, Anathea Pepperl

Theses and Dissertations

One of the major obstacles to pressure ulcer research is the difficulty in accurately measuring mechanical loading of specific anatomical sites. A human motion analysis system capable of automatically segmenting a patient's body into high-risk areas can greatly improve the ability of researchers and clinicians to understand how pressure ulcers develop in a hospital environment. This project has developed automated computational methods and algorithms to analyze pressure images acquired in a hospital setting. The algorithm achieved 99% overall accuracy for the classification of pressure images into three pose classes (left lateral, supine, and right lateral). An applied kinematic model ...