Engineering Commons^™

Segmentation Of Intracranial Structures From Noncontrast Ct Images With Deep Learning, Evan Porter

Wayne State University Dissertations

Presented in this work is an investigation of the application of artificially intelligent algorithms, namely deep learning, to generate segmentations for the application in functional avoidance radiotherapy treatment planning. Specific applications of deep learning for functional avoidance include generating hippocampus segmentations from computed tomography (CT) images and generating synthetic pulmonary perfusion images from four-dimensional CT (4DCT).A single institution dataset of 390 patients treated with Gamma Knife stereotactic radiosurgery was created. From these patients, the hippocampus was manually segmented on the high-resolution MR image and used for the development of the data processing methodology and model testing. It was determined that …

Multiparametric Quantitative Acoustic Imaging Of Cervical Remodeling During Pregnancy, Yan Yan

Wayne State University Dissertations

The uterine cervix plays a central role in the maintenance of pregnancy and the process of parturition. Untimely cervical ripening in early gestation predisposes to preterm labor and delivery, the leading cause of infant mortality worldwide. The current approach to evaluate the status of the cervix relies on digital and sonographic examination, which indicates the morphological changes of the cervix (cervical length). Therefore, assessing cervix tissue composition changes may provide more sensitive evaluations about cervix status beyond cervical length. Photoacoustic (PA) imaging is a relatively new, non-invasive ultrasound (US) based technology that captures acoustic signals emitted by tissue components in …

Assessing Midbrain Abnormalities In Parkinson’S Disease Using Magnetic Resonance Imaging, Kiarash Ghassaban

Wayne State University Dissertations

Diagnosing early-stage Parkinson’s disease (PD) and its manifestations is still a clinical challenge. Previous imaging studies using iron, neuromelanin (NM) and the Nigrosome-1 (N1) measures in the substantia nigra (SN) by themselves have been unable to provide sufficiently high diagnostic performance for these methods to be adopted clinically. In this dissertation, we start by studying idiopathic PD patients at their intermediate stages of the disease to evaluate the role of global and regional iron in the major deep gray matter nuclei. Then, we only focus on the NM complex in the midbrain and how neuronal loss interact with iron overload …

The Advanced Applications For Optical Coherence Tomography In Skin Imaging, Qiuyun Xu

Wayne State University Dissertations

Optical coherence tomography (OCT), based on the principle of interferometry, is a fast and non-invasive imaging modality, which has been approved by FDA for dermatologic applications. OCT has high spatial resolution up to micrometer scale compared to traditional ultrasound imaging. In addition, OCT can provide real-time cross-sectional images with 1 to 2 mm penetration depth, which makes it an ideal imaging technique to assess the skin micro-morphology and pathology without any tissue removal. Many studies have investigated the possibilities of using OCT to evaluate dermatologic conditions, such as skin cancer, dermatitis, psoriasis, and skin damages. Hence, OCT has tremendous potential …

Investigation Of Physiochemical Properties And Biocompatibility Of Amourphos Calcium Polyphosphate Hydrogel Doped With Antibiotics And Injectable Polymeric Dicalcium Phosphate Dihydrate Bone Cement, Yasaman Chehreghanianzabi

Wayne State University Dissertations

Amorphous calcium polyphosphate (ACPP) is an inorganic polymer ceramic. Here we use a simple method of preparing ACPP hydrogel in the presence of excess volume of water. Essentially, water availability to polyphosphate chains accelerates water molecule ingress and microstructural transformation of ACPP hydrogels. Antibiotic delivery capacity of ACPP hydrogel increases by the specific mixing and molding method, where the VCM has higher antibiotic encapsulation efficiency with the small burst release for the compressed discs. In part of this study, we investigate impact of ACPP hydrogel replacement by monomeric calcium phosphate on the quality of final product (dicalcium phosphate dihydrates (DCPD) …

Computational Analysis Of Oxidative Stress In Endothelial Dysfunction: Insights On The Role Of Tetrahydrobiopterin, Ascorbate And Glutathione, Sheetal Kedar Panday

Wayne State University Dissertations

Oxidative stress and endothelial dysfunction are reported in the cardiovascular and neurovascular diseases. Oxidative stress is caused due to an increase in the generation of reactive oxygen (ROS) and nitrogen species (RNS) and incapacity of antioxidant systems to eliminate ROS and RNS. Endothelial dysfunction is characterized by a reduction in nitric oxide (NO) bioavailability. NO is constitutively produced by enzyme endothelial nitric oxide synthase (eNOS). A reduction in tetrahydrobiopterin (BH4), which is an essential cofactor of eNOS, can lead to eNOS uncoupling. There is complex interplay between the ROS/RNS and antioxidant system underlying pathophysiologies of vascular diseases, however our quantitative …

Evaluation Of Far-Side Occupant Safety Based On Numerical Modeling, Syed Akhtar Imam

Wayne State University Dissertations

The objective of this study was to augment the knowledge of the far-side occupant injury biomechanics in side impact vehicle crashes. Most research studies conducted to investigate the far-side occupant injuries are through the field crash data for a better understanding of human impact responses, injury mechanisms, and injury tolerance levels. The data obtained from field data is also used in the development of injury mitigation technologies, such as safety belts, airbags, etc. A field data represents the injury outcome of an automotive crash, but it doesn’t leave behind enough information for in-depth knowledge. The use of cadaver is the …

Development Of Rat Head Finite Element Model And Tissue Level Biomechanical Threshold For Traumatic Axonal Injury, Runzhou Zhou

Wayne State University Dissertations

Traumatic brain injury (TBI) is caused by local tissue deformation at the time of trauma, leading to neurological dysfunction. In the United States alone, 2.87 million people sustain a TBI each year, of which one-fifth results in death. Traumatic axonal injury (TAI) is a well-recognized consequence of every fatal head injury and more than 85% of vehicular crash-related blunt head injuries. The most common and important pathologic feature of TBIs are multifocal changes to axons in the white matter produced by rapid head acceleration/deceleration during a traumatic event with consequent local shear/tension on neural tissue and axons contributing to secondary …

Development Of Photoacoustic Tomographic Systems For Brain Hemorrhage Detection, Karl Kratkiewicz

Wayne State University Dissertations

Preterm neonates (age) and/or with low birth weight (

Photoacoustic imaging (PAI) is an imaging modality which derives its contrast from differences in optical absorption coefficients of tissue through laser irradiation and acoustic detection. Therefore, PAI derives its signal directly from optical absorbers such as blood; the critical component in a hemorrhage. We discuss operation and processing methods of our Verasonics Vantage system. We then investigate thermal safety of PAI in mouse model for various laser pulse repetitions rates and illumination duration. We then develop two photoacoustic tomographic systems for eventual translation to clinic for hemorrhage detection. One system being …

Titanium Nitride Nanotube Electrodes Used In Neural Signal Recording Application And Neurotransmitter Detection, Gui Chen

Wayne State University Dissertations

Electrode probes are devices widely used for stimulating and recording neural cell signals in the neuroscience field, which can convert the ion potential generated by electrochemical activities into an electronic potential that can be measured by the external instrument systems. A stable neural interface that effectively communicates with the nervous system via electrode is much important for the robust recording and the long-term monitoring of the activity of the neural signals. These probes are designed to minimize tissue damage for superior signal quality. Each probe’s mechanical, geometric, and electrical characteristics are precise and highly reproducible for consistent, high-quality results. There …

In Vitro Atherosclerosis Disease Model Via The Ring Stacking Method, Cameron Brandon Pinnock

Wayne State University Dissertations

Creation of an in vitro atherosclerotic disease model using the novel Ring Stacking Method. Singular self-assembling tissue rings made up smooth muscle cells and fibrin hydrogel are stacked on one another to create a tissue engineered vessel. These biologically engineered blood vessels are then seeded with endothelial cells via combined static rotational and dynamic bioreactor in order to create a functional intima layer. Early stage atherosclerosis was induced via the addition of oxidized low-density lipoproteins (ox-LDL) to the fibrin hydrogel that creates the media layer of the engineered vessel. After the creation of the intima layer the engineered vessel was …

Development Of A Novel Cardiac Ischemia-Reperfusion Model In The Axolotl, Jeremy Tolentino Llaniguez

Wayne State University Dissertations

The Center for Disease Control’s National Center for Health Statistics data for mortality from diseases of the heart show the age-adjusted death rate has fallen from almost 600 deaths in the 1950s to just over 190 deaths per 100,000 U.S. residents today. With the recognized limitations of pharmacotherapy of myocardial infarction (MI), cell-based therapies have been undergoing rapid development and clinical testing. However, there is still no consensus about cell types, delivery routes, dosing and treatment schedules and pretreatment conditioning of cells prior to administration. Furthermore, a fundamental question remains unanswered about the reasons for the poor capacity for myocardial …

Incorporating Cardiac Substructures Into Radiation Therapy For Improved Cardiac Sparing, Eric Daniel Morris

Wayne State University Dissertations

Growing evidence suggests that radiation therapy (RT) doses to the heart and cardiac substructures (CS) are strongly linked to cardiac toxicities, though only the heart is considered clinically. This work aimed to utilize the superior soft-tissue contrast of magnetic resonance (MR) to segment CS, quantify uncertainties in their position, assess their effect on treatment planning and an MR-guided environment.

Automatic substructure segmentation of 12 CS was completed using a novel hybrid MR/computed tomography (CT) atlas method and was improved upon using a 3-dimensional neural network (U-Net) from deep learning. Intra-fraction motion due to respiration was then quantified. The inter-fraction setup …

Spatiotemporal Release Of Growth Factors In A Biomaterial-Focused Organotypic Spinal Cord Injury Model, Elizabeth Mays

Wayne State University Dissertations

Over 17,000 people per year in the United States sustain a spinal cord injury (SCI) for which there is no gold standard of care and life-long complications. SCI is a complex wound environment with various growth factors (GFs), cellular activity, and scar formation at various timepoints. For example, basic fibroblast growth factor (bFGF) is released immediately to protect local support cells, namely oligodendrocytes (OLs). Brain derived neurotrophic factor (BDNF) has peak expression at 2-3 days in mice and 5-7 days in humans, and aids axonal growth across the injury site. Incidentally this is around the same time as M1 macrophage …

Utilizing Immunopet To Measure Tumor Response To Treatment In Breast Cancer, Brooke Mcknight

Wayne State University Dissertations

With a broad spectrum of therapies available for treating breast cancer, the need for personalized medicine tailoring the cure according to phenotype is evident. Such an approach may be fully realized with the development of quantitative imaging technologies for disease detection, staging and diagnosis, without increasing patient burden. Immuno-positron emission tomography (PET) combines the targeted specificity of antibodies with the sensitivity of PET for whole body imaging by targeting molecular features amplified in lesions. ImmunoPET probes targeting different antigens and their utility to measure response to treatment were explored. 89Zr-trastuzumab was employed as a surrogate readout of Src inhibition after …

Optimization Of Underbody Blast Energy-Attenuating Seat Mechanisms Using Modified Madymo Hybrid Iii And Human Body Models, Kelly Erin Bryan Bosch

Wayne State University Dissertations

Energy attenuating (EA) blast seats, although not new to the market, have not been fully characterized with respect to energy attenuation capability and the resulting effects on occupant protection. EA seats utilize stroking mechanisms to absorb energy and reduce the vertical forces imparted on the occupant’s pelvis and lower spine complex. Although a variety of EA seats are available on the market, the fundamental question behind how to optimize the force and deflection rates of the EA mechanisms to effectively reduce occupant injury has not yet been answered. Using modeling and simulation techniques, this research developed a tool to determine …

Development Of A Novel Ultrasound/Photoacoustic Tomography System For Breast Cancer Imaging Using Full-Ring Illumination Mode, Suhail Salem Alshahrani

Wayne State University Dissertations

Breast cancer is a significant health problem, not only in the United States but globally. In the last year, breast cancer was the second leading cause of cancer deaths in the United States. In addition, the incidence rates of invasive and in situ female breast cancer increased in all age classes between 1975 and 2014. Early detection is a critical component in effectively managing this disease. One of the challenges of early detection of breast cancer lies in the availability and accuracy of diagnostic imaging. Several modalities for early detection are currently available and in use. One of the most …

Engineering Hyaluronic Acid Carbon Nanotube Nanofibers: A Peripheral Nerve Interface To Electrically Stimulate Regeneration, Elisabeth M. Steel

Wayne State University Dissertations

Peripheral nerve injuries annually affect hundreds of thousands of people globally. Current treatments like the gold standard autograft and commercially available nerve guide conduits (NGC) are insufficient to repair long gap peripheral nerve injuries. NGCs can aid recovery but lack key microenvironment cues that promote nerve regeneration. We hypothesized that providing topographical, mechanical, and electrical guidance cues through a nanofibrous composite biopolymer would result in improved neuron growth metrics using an in vitro model. We embedded hydrophilic carbon nanotubes (CNT) within hyaluronic acid (HA) nanofibers by electrospinning. The aims of this study were (1) to define the topographical, nanomechanical, and …

Study Of Mri Signal In The Presence Of Discrete Spherical Magnetic Particles, Paul Kokeny

Wayne State University Dissertations

Simulating signal behavior in Magnetic Resonance imaging (MRI) is often a necessary step in being able to understand how signal relates to certain physiological parameters. One such parameter of interest in the body is magnetic susceptibility since it is related to iron content. The bulk magnetic susceptibility of an object is a property that describes how magnetized it becomes when placed in an external magnetic field. When the bulk susceptibility of an object arises from the presence of discrete magnetic inclusions, the MRI phase signal inside the object can no longer be determined analytically by assuming it has a continuous …

Identification Of Streptococcus Pyogenes Using Raman Spectroscopy, Ehsan Majidi

Wayne State University Dissertations

Despite the attention that Raman Spectroscopy has gained recently in the area of pathogen identification, the spectra analyses techniques are not well developed. In most scenarios, they rely on expert intervention to detect and assign the peaks of the spectra to specific molecular vibration. Although some investigators have used machine-learning techniques to classify pathogens, these studies are usually limited to a specific application, and the generalization of these techniques is not clear. Also, a wide range of algorithms have been developed for classification problems, however, there is less insight to applying such methods on Raman spectra. Furthermore, analyzing the Raman …

Development Of A Programmed Electrospun Three Dimensional (3d) Nanofiber Collecter And It’S Application To Orthopedic Implant Coatings, Liang Chen

Wayne State University Dissertations

Orthopedic implants might not directly unite with bones especially in compromised patients even if they have been appropriately fixed. The lack of early osseointegration would lead to the failure of the orthopedic implant. A “bone-like” implant surface is urgently needed to accelerate osseointegration. Electrospun nanofiber (NF) is a promising implant coating due to its highly porous nanoscale structure. It mimics the collagen I nanofibrous network of bone tissue; meanwhile it has been widely used as a drug delivery device. However, its compact and dense structure is not ideal for cell growth. Our strategy was to develop a functional three-dimensional (3D) …

Brain Connectivity After Concussion, Armin Iraji

Wayne State University Dissertations

Mild traumatic brain injury (mTBI) accounts for over one million emergency visits in the United States each year. While most mTBI patients have normal findings in clinical neuroimaging, alterations in brain structure and functional connectivity have frequently been reported. In this study, we investigated the large-scale brain structural and functional connectivity using diffusion MRI and resting-state fMRI data. Data from 40 mTBI patients was acquired at the acute stage (within 24 hrs after injury). 35 patients returned for data acquisition at a follow-up (4-6 weeks after injury). Data was also collected from a cohort of 58 healthy subjects, 36 of …

Mri Methods For Imaging The Feto-Placental Vasculature And Blood, Uday Krishnamurthy

Wayne State University Dissertations

Fetal magnetic resonance imaging (MRI) in recent times has become a well-established adjunct to ultrasound (US) in routine clinical prenatal care and diagnostics. The majority of fetal MRI is restricted to T2-weighted scans, where the diagnosis is based on the appearance of normal and abnormal tissue. Although there have been many advancements in MRI and a plethora of sequences, that probe different anatomical and different physiological process, the adaptation of these in fetal imaging has been rather slow. Many of these can extract quantitative parameters that can throw light on the underlying tissue’s normal/patho-physiology. But the use of such quantitative …

Pet Imaging Of Early Therapeutic Response In Solid Tumors, Stephanie J. Blocker

Wayne State University Dissertations

An important pillar of precision medicine for oncology is the ability to identify patients who respond to treatment early into their therapy. Positron emission tomography (PET) allows physicians and researchers to measure changes in tumor behavior prior to noticeable differences in morphology.

Objective: Determine the utility of multiple tracers for PET in assessing early changes in tumor activity that result from treatment.

Methods: Two tracers for PET were studied. 64Cu-labeled liposomes were used to assess changes in liposome delivery two solid colon tumors early into treatment with bevacizumab (Bev). 18F-FMAU thymidine analog (1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)thymine), was utilized to detect early response to …

Biomechanics Of Concussion: The Importance Of Neck Tension, Ron Jadischke

Wayne State University Dissertations

Linear and angular velocity and acceleration of the head are typically correlated to concussion. Despite improvements in helmet performance to reduce accelerations, a corresponding reduction in the incidence of concussion has not occurred (National Football League [NFL] 1996 – present).

There is compelling research that forces on and deformation to the brain stem are related to concussion. The brain stem is the center of control for respiration, blood pressure and heart rate and is the root of most cranial nerves. Injury to the brain stem is consistent with most symptoms of concussion reported in the National Football League and the …

Design Of A Modular Endothelialized Platform For Vascularized Bone Regeneration, Kevin Barrett Miles

Wayne State University Dissertations

The gold standard for bone regeneration requires harvesting a piece of healthy bone from the patient through a painful procedure, but this piece of autologous bone graft contains the bone and endothelial cells required to rapidly regenerate bone in a defect. We have developed a modular bone regeneration platform, composed of mesenchymal stem cells (MSCs) and hydroxyapatite (HAP) microgranules encapsulated in microcapsules, to replace autologous graft harvesting. The microcapsules are composed of a polyelectrolyte membrane formed by the ionic-complex reaction between chondroitin 4-sulfate (C4S) and chitosan. The specific aims of this thesis were to 1) examine the ability of C4S/HAP/chitosan …

Development Of A Finite Element Pelvis And Lower Extremity Model With Growth Plates For Pediatric Pedestrian Protection, Ming Shen

Wayne State University Dissertations

Finite element (FE) model is a useful tool frequently used for investigating the injury mechanisms and designing protection countermeasures. At present, no 10 years old (YO) pedestrian FE model has been developed from appropriate anthropometries and validated against limitedly available impact response data. A 10 YO child FE pelvis and lower extremities (PLEX) model was established to fill the gap of lacking such models in this age group. The baseline model was validated against available pediatric postmortem human subjects (PMHS) test data and additional scaled adult data, then the PLEX model was integrated to build a whole-body FE model representing …

Mechanical Interventions In Soft Tissue Repair, Elizabeth Marie Meier

Wayne State University Dissertations

This body of work sets to investigate some of these mechanical interventions that are designed to promote wound healing, repair, or even replace an injured tissue. By investigating three separate tissues and three separate mechanical interventions, we can draw conclusions about the implications of including mechanical interventions in biomedical research and clinical treatments. The use of sutures to close wounds is highly common, however the effects of sutures on the tensile mechanics of human skin are largely unknown. To evaluate how sutures may affect uniaxial tensile mechanics, human skin samples were sutured and loaded in tension in multiple orientations. The …

Biomaterials Approaches For Utilizing The Regenerative Potential Of The Peripheral Nerve Injury Microenvironment, Melissa Renee Wrobel

Wayne State University Dissertations

Clinically available treatments are insufficient to achieve full functional recovery in large (>3cm) peripheral nerve injuries (PNI). The objectives in this thesis were 1) to study often overlooked elements of intrinsic PNI repair including release of inhibitory CSPGs and post-injury responses of inflammatory macrophages and dedifferentiated Schwann cells; 2) to create biomaterial scaf-folds featuring topographical and adhesive cues to enhance neurite outgrowth; and 3) to test the ability of those cues to direct macrophages and Schwann cells towards a pro-regenerative phe-notype. It is hypothesized that recapitulating the positive and negative cues of the PNI microenvi-ronment can better improve regeneration. …

Development Of Carbon Based Neural Interface For Neural Stimulation/Recording And Neurotransmitter Detection, Wenwen Yi

Wayne State University Dissertations

Electrical stimulation and recording of neural cells have been widely used in basic neuroscience studies, neural prostheses, and clinical therapies. Stable neural interfaces that effectively communicate with the nervous system via electrodes are of great significance. Recently, flexible neural interfaces that combine carbon nanotubes (CNTs) and soft polymer substrates have generated tremendous interests. CNT based microelectrode arrays (MEAs) have shown enhanced electrochemical properties compared to commonly used electrode materials such as tungsten, platinum or titanium nitride. On the other hand, the soft polymer substrate can overcome the mechanical mismatch between the traditional rigid electrodes (or silicon shank) and the soft …