Biomedical Engineering and Bioengineering Commons^™

Recovering Local Neural Tract Directions And Reconstructing Neural Pathways In High Angular Resolution Diffusion Mri, Ning Cao

Theses and Dissertations--Computer Science

Magnetic resonance imaging (MRI) is an imaging technique to visualize internal structures of the body. Diffusion MRI is an MRI modality that measures overall diffusion effect of molecules in vivo and non-invasively. Diffusion tensor imaging (DTI) is an extended technique of diffusion MRI. The major application of DTI is to measure the location, orientation and anisotropy of fiber tracts in white matter. It enables non-invasive investigation of major neural pathways of human brain, namely tractography. As spatial resolution of MRI is limited, it is possible that there are multiple fiber bundles within the same voxel. However, diffusion tensor model is …

Investigation Of Nanoparticle Delivery To Cancer Cells By Conjugation With Various Targeting Moieties, Leila Hossein Rashidi

Bioengineering Theses - Archive

Recently, mapping and profiling of specific tumor biomarkers characterizing cancer cells, followed by understanding of signal cascades involved in the pathogenesis of tumors (targeted therapy), as well as diagnosis in early stages, have become promising topics in cancer research. Since, the most considerable limitations of conventional therapies and diagnostic modalities are associated with nonspecific targeting; designing intelligent new anti-cancer nanocarries improved by targeting biomolecules could enhance therapeutic efficiencies as well as diagnosis in early stage of cancer. Active targeting which is based on the surface accessibility and the high level of expression of specific cancer antigens has attracted much attention …

Effect Of Body Mass Index On The Biomechanical Properties Of Anterior Vaginal Wall Tissue Of Prolapsed Patients, Sandra Gabriela Ochoa Lopez

Bioengineering Theses - Archive

Anterior Vaginal Wall (AVW) prolapse is a bothersome condition that affects thousands of women. Its onset and progression is not well understood but is thought to be multifactorial. Biomechanical properties of AVW tissue from prolapsed patients have been measured in-vitro using excised tissue specimens with great variability found in results, possibly from differences in tissue preparation, setting, preservation time, temperature, hydration, etc. In-vivo test using a BTC-2000TM cutometer-like device has recently been developed that measures the tissue uplift under suction pressure load. In this study, a systematical analysis of biomechanical property measurements from AVW tissues was done, including both in-vitro …

Measurement Of Transverse Relaxation Times Of Cerebral Metabolites In Brain Tumors, Akshay Madan

Bioengineering Theses - Archive

Proton (¹H) magnetic resonance spectroscopy (MRS) provides a non-invasive means of assessing metabolite concentration for a range of biologically important cerebral compounds in vivo. To extract quantitative information, additional data regarding proton spin relaxation phenomena is critical. Transverse relaxation times (T₂) of cellular metabolites depend on the local molecular environment in which they reside. Several neurological diseases alter the molecular environment, which may be reflected in the changes of the T₂ relaxation times. Therefore alterations in T₂ in tumors may provide important information about the local environment and a potential non-invasive diagnostic tool. Thirty-seven adult patients with gliomas and 11 …

Microfluidic Chip-Based Fabrication Of Hollow Alginate Microfiber For Enzyme Entrapment And Reaction, Uyen Hoang Thao Pham

Bioengineering Theses - Archive

This thesis demonstrates a simple process to generate alginate hollow microfibers by using a non-lithographic PDMS microfluidic device. The microfluidic device was fabricated by a novel template method in a wet lab without the support of any conventional lithography techniques. The relationships of the flow rate and the diameter of hollow alginate fibers were characterized. It was found that the outer diameter of the alginate hollow fiber was independent of the flow rate, but the core flow and sheath flow played an important role to control the internal diameter and the wall thickness of the alginate hollow microfiber. At a …

Design, Fabrication And Evaluation Of A Novel Microfluidic Based In Vitro Cell Migration Assay, Sai Sirisha Dhavala

Bioengineering Theses - Archive

Microfabrication and microfluidic devices have been recognized as potential platforms for cell-based and drug screening studies. Human glioblastoma multiforme (hGBM) cells migrate inside the central nervous system (CNS) in narrow space constrictions and rarely metastasize through bloodstream. Hence, microfluidic devices consisting of narrow channels are considered as suitable models to study cell migration in vitro. Further the migratory capability of each individual cell could be easily obtained and quantified using such system. This effort presents the design and development of an alternative microfluidic system that provides an integrated array of channels for screening multiple drugs simultaneously. This system is an …

Reliable Frontal Cortex Activity For An Oral Stroop Task Using Functional Near Infrared Spectroscopy, Matthew Allen Cloud

Bioengineering Theses - Archive

Analysis tools such as HomER and NIRS-SPM for functional Near-Infrared systems are commercially or freely available; however, they are difficult for clinicians to use as an assessment tool. One barrier to their use is the reliability of a given functional test. Intraclass correlation coefficients (ICC) provide a measure of group and individual reliability. NIRS-SPM was extended with ICC to assess a two part modified Stroop task. The protocol was repeated once every two weeks over a period of one month. Changes in neural activity attributed to inhibition of distraction, show significant covariance to the protocol with moderate to strong reliability …

Metacom: Automated Data Processing And Analysis Of Metagenomic Community Sequences, Cody A. Tramp, Charles D. Miller

Browse all Datasets

Advances in next generation sequencing technology have allowed metagenomic researchers to study the composition of bacterial communities through analysis of the vast numbers of sequence reads that these technologies generate. It is not feasible to analyze and interpret this large amount of data manually and individual research groups must create automated scripts and programs to analyze this data. Here, we present MetaCom, a program that offers a common set of analysis and organizational tools that can be used by research groups in the analysis of environmental samples. MetaCom is an open-source software tool that can process next generation sequencing output, …

Automatic Detection Of Polypoid Skin Lesions: The Squash Sign, Saurabh G. Karnik

Masters Theses

“Earlier detection of malignant melanoma can save lives. Automatic in-vivo methods of melanoma detection including smart-phone applications are now available, but specificity is low, i.e. too many benign lesions are detected as possible melanomas. Polypoids, elevated and rounded lesions are one class of benign lesions. These raised lesions with piecewise circular borders, predominantly intradermal nevi and cutaneous polyps (IDNs), are always benign. Variegated coloring present in polypoid lesions can lead physicians to perform an unneeded biopsy. Contact dermatoscope plates with gel squash these lesions, leaving a “squash sign” marker of benignancy which can be automatically detected. We present a method …

Significance And Analysis Of Milia-Like Cysts In Dermoscopy Skin Lesion Images, Sneha K. Mahajan

Masters Theses

“Milia-like cysts (MLCs) are dermoscopic structures frequently observed in seborrheic keratoses(SKs), which are the most common type of skin lesions. Diverse appearances of these skin lesions make them difficult to differentiate from melanoma, a deadly type of skin cancer. Classified by size into two main groups, starry MLCs and cloudy MLCs, the presence of these structures in a skin lesion has been known to help differentiate benign lesions from melanoma. Though the presence of cloudy MLCs is not exclusively associated with SKs, they can be a useful tool to differentiate SKs from melanoma. This research study determines the statistical occurrence …

Studies Of Functionalized Nanoparticles For Smart Self-Assembly And As Controlled Drug Delivery, Xiaochu Ding

Dissertations, Master's Theses and Master's Reports - Open

This dissertation is related to the studies of functionalized nanoparticles for self-assembly and as controlled drug delivery system. The whole topic is composed of two parts. In the first part, the research was conducted to design and synthesize a new type of ionic peptide-functionalized copolymer conjugates for self-assembly into nanoparticle fibers and 3D scaffolds with the ability of multi-drug loading and governing the release rate of each drug for tissue engineering. The self-assembly study confirmed that such peptide-functionalized amphiphilic copolymers underwent different self-assembly behavior. The bigger nanoparticles were more easily assembled into nanoparticle fibers and 3D scaffolds with larger pore …

Independent Component Analysis Enhancements For Source Separation In Immersive Audio Environments, Yue Zhao

Theses and Dissertations--Electrical and Computer Engineering

In immersive audio environments with distributed microphones, Independent Component Analysis (ICA) can be applied to uncover signals from a mixture of other signals and noise, such as in a cocktail party recording. ICA algorithms have been developed for instantaneous source mixtures and convolutional source mixtures. While ICA for instantaneous mixtures works when no delays exist between the signals in each mixture, distributed microphone recordings typically result various delays of the signals over the recorded channels. The convolutive ICA algorithm should account for delays; however, it requires many parameters to be set and often has stability issues. This thesis introduces the …

Reducing Radiation Dose To The Female Breast During Conventional And Dedicated Breast Computed Tomography, Franco Rupcich

Dissertations (1934 -)

The purpose of this study was to quantify the effectiveness of techniques intended to reduce dose to the breast during CT coronary angiography (CTCA) scans with respect to task-based image quality, and to evaluate the effectiveness of optimal energy weighting in improving contrast-to-noise ratio (CNR), and thus the potential for reducing breast dose, during energy-resolved dedicated breast CT.

A database quantifying organ dose for several radiosensitive organs irradiated during CTCA, including the breast, was generated using Monte Carlo simulations. This database facilitates estimation of organ-specific dose deposited during CTCA protocols using arbitrary x-ray spectra or tube-current modulation schemes without the …

Vascular Changes In Type 2 Diabetes Mellitus: Application To Restenosis After Stenting, Hongfeng Wang

Dissertations (1934 -)

Stents used to decrease cardiovascular risk in patients with type 2 diabetes mellitus (T2DM) are prone to increased rates of restenosis. The mechanisms are incompletely elucidated, but low wall shear stress (WSS) and altered intracellular signaling likely contribute. We tested the hypothesis that neointimal hyperplasia (NH) after bare-metal stenting is due to vascular remodeling (enhanced formation of advanced glycation end-products (AGEs), increased downstream vascular resistance (DVR), and decreased WSS), and that decreasing AGEs with ALT-711 (Alagebrium) mitigates this response.

Stents were implanted into the abdominal aorta of Zucker lean (ZL), obese (ZO), and diabetic (ZD) rats. After 21 days, the …

Diffusion Tensor Imaging Of The Central Nervous System Following An Injury To The Spinal Cord And Cell Transplant, Michael Jirjis

Dissertations (1934 -)

The purpose of this dissertation research was to characterize the use of magnetic resonance diffusion tensor imaging (DTI) as a diagnostic and prognostic tool in understanding the changes that occur throughout the spinal cord and brain following a spinal cord injury (SCI) and following stem cell transplant. The diffusion of water inside the nervous system is dramatically altered around the lesion site following a traumatic SCI. However, following damage to the spinal cord, little is known about the diffusion characteristics away from an injury and even less is understood about DTI's sensitivity to structural changes that occur following regenerative transplant …

Foot And Ankle Motion Analysis Using Dynamic Radiographic Imaging, Benjamin Donald Mchenry

Dissertations (1934 -)

Lower extremity motion analysis has become a powerful tool used to assess the dynamics of both normal and pathologic gait in a variety of clinical and research settings. Early rigid representations of the foot have recently been replaced with multi-segmental models capable of estimating intra-foot motion. Current models using externally placed markers on the surface of the skin are easily implemented, but suffer from errors associated with soft tissue artifact, marker placement repeatability, and rigid segment assumptions. Models using intra-cortical bone pins circumvent these errors, but their invasive nature has limited their application to research only. Radiographic models reporting gait …

Mechanisms Of Sensorimotor Impairment In Multiple Sclerosis, Matthew Cheeming Chua

Dissertations (1934 -)

Sensorimotor impairments in people with multiple sclerosis (MS) might alter coordination and balance strategy during functional movements. People with MS often have symptoms such as weakness and discoordination in the lower limbs, resulting in poor walking and balance function. This decrease in function can result in falls, decreased community activity, unemployment, and reduced quality of life. As MS is a progressive disease resulting in a range of dysfunction, the amount of lower limb impairment can cause changes to walking and balance strategies to maintain functional performance. The overall objective of this dissertation was to quantify the impairment at the hip …

The Case For Interposed Abdominal Compression Cpr In Hospital Settings, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Interposed abdominal compression (IAC)-CPR includes all steps of standard external CPR with the addition of manual mid-abdominal compressions in counterpoint to the rhythm of chest compressions. IAC-CPR can increase blood flow during CPR about two fold compared to standard CPR without IAC, as shown by multiple studies in computer and animal models. The technique increases the rate return of spontaneous circulation (ROSC) for in-hospital resuscitations from roughly 25% to 50%. Improved survival to discharge is demonstrated in two in-hospital trials. IAC as an adjunct technique is quickly taught and is less complex than most other basic life support maneuvers. A …

Induced Damping And Its Relationship To Beneficial Energy Harvesting In Dielectric Elastomers With Application To Walking, Heather L. Lai

Wayne State University Dissertations

This dissertation presents a novel, interdisciplinary research which addresses the potential of applying soft polymeric materials to strategically harvest biomechanical energy in a beneficial manner for use as a viable, low power source for on-board electronics. Of particular interest are electroactive polymers (EAP), which unlike other types of electromechanical smart materials such as piezoelectric ceramics, which are often brittle, have low elastic modulus and can exhibit large strains without substantial stress generations. One type of EAP, the dielectric elastomer (DE), which utilizes electrostatic forces built up across the dielectric polymer to convert between electrical and mechanical energy, is employed in …

Visual Exploration And Information Analytics Of High-Dimensional Medical Images, Darshan Pai

Wayne State University Dissertations

Data visualization has transformed how we analyze increasingly large and complex data sets. Advanced visual tools logically represent data in a way that communicates the most important information inherent within it and culminate the analysis with an insightful conclusion. Automated analysis disciplines - such as data mining, machine learning, and statistics - have traditionally been the most dominant fields for data analysis. It has been complemented with a near-ubiquitous adoption of specialized hardware and software environments that handle the storage, retrieval, and pre- and postprocessing of digital data. The addition of interactive visualization tools allows an active human participant in …