Engineering Commons^™

Photosynthetically Active Protoplasts For Power Scavenging, Absorbance And Optical Density Analysis, Ahmed Shahid

Bioengineering Theses

Plants and photosynthetic bacteria hold protein molecular complexes that can efficiently harvest photons. This paper presents fundamental studies to harness photochemical activities by converting photonic energy into electrical energy. The electrical behavior of protoplast extracted from Arabidopsis plants was characterized in the presence and absence of light. The photo-induced reactions of photosynthesis were measured using a patch clamp measurement system at a constant voltage. This research also reports the absorbance and optical density measurements showing very large bandwidth for extracted protoplasts. The optical measurements were performed on the protoplast Arabidopsis and showed absorption bands at a number of wavelengths. The …

3-Dimensional Scanning And Reconstruction Using A Modified Hrt-Rcm Corneal Confocal Microscope, Saurabh Vaidya

Bioengineering Theses

The HRT II - Rostock Corneal Module (HRT II-RCM) provides excellent resolution, contrast and optical sectioning capability for cornea imaging. It offers the most detailed views of cornea structure and pathology. However, the major limitation of this microscope is its scanning method. It has a threaded dial on the front side of the microscope which is coupled to the objective, and this dial has to be rotated manually to change the focal plane and to scan through the cornea.The dial is within inches of the cornea. During the scans, manual control causes serious interference and degrades the quality of the …

Creep Behaviour Of Hand Laminated Glass Reinforced Polymer Composites., Brain Quinn

Theses

The creep behaviour of hand laminated, glass fiber reinforced polyester composites were studied at coupon level, due to the use of similar materials in long term load bearing civil and structural engineering applications. Creep predictions were made by fitting the parameters of several viscoelastic models to experimental creep data as well as two accelerated test methods, time temperature superposition (TTS) and frequency time transformations (FTT). TTS experiments were carried out in a dynamic mechanical analyzer (DMA) in three point bending mode for three types of material systems. Creep compliance master curves representing the linear viscoelastic creep response at reference temperatures …

Composition-Structure-Property Relationships For Experimental Composite Nerve Guidance Conduits, Xiaofang Zhang

Theses

Many Nerve Guidance Conduits (NGCs) have been approved by the Food and Drug Administration (FDA) as an alternative to nerve autografting for guiding peripheral nerve regeneration. However these materials offer little therapeutic potential for favourable axon growth environment, and difficulty in balancing the mechanical properties and the degradation rate of the implanted material is also a contemporary challenge. This project involved the design of experimental composite NGCs comprising glass particles and Pluronic FI27 in the copolymer (poly(lactic-co-glycolic acid)) and examined the composition-structure-property relationships for such materials. Three glasses (0.5Si-(x) Na-0.2Ca-0.13Zn-(0.17-x) Ce) (0.0.04 > x > 0.14) were produced. Glasses were characterised using …

Monitoring, Diagnosis, And Control For Advanced Anesthesia Management, Zhibin Tan

Wayne State University Dissertations

Modern anesthesia management is a comprehensive and the most critical issue in medical care. During the past dacades, a large amount of research works have been focused on the problems of monitoring anesthesia depth, modeling the dynamics of anesthesia patient for the purpose of control, prediction, and diagnosis.

Monitoring the anesthesia depth is not only for keeping the patient in adquate anesthesia level but also for preventing the patient from overdosing. Several EEG based indexes have been developed such as the BIS, and Entropy etc. for measuring depth. However, reports mentioned that those indexes in some cases fail in detecting …

Finite Element Reconstruction Of Real World Aortic Injury In Near-Side Lateral Automotive Crashes With Conceptual Countermeasures, Aditya Neelakanta Belwadi

Wayne State University Dissertations

Traumatic rupture of the aorta (TRA) remains the second most common cause of death associated with motor vehicle crashes after brain injury. On an average, nearly 8,000 people die annually in the United States due to blunt injury to the aorta. It is observed that more than 80% of occupants who suffer an aortic injury die at the scene due to exsanguination into the chest. With the advent of more accurate and established human body finite element (FE) models, FE crash reconstruction methods may become a valuable tool when assessing crash scenarios and occupant injury mechanisms.

The current study is …

An Investigation Of The Biomechanical Response From Shock Wave Loading To The Head, Alessandra Dal Cengio Leonardi

Wayne State University Dissertations

There is a pressing need for a comprehensive explanation of the mechanism of brain injury after exposure to blast and several hypotheses have been suggested. The focus of this research was to investigate one of the hypotheses for primary brain injury due to blast: multimodal skull flexure. The significance of this research is twofold. First, resolution of the mode of energy transfer and of the induced stresses within the skull-brain system will allow for creations of mitigation/protective techniques/equipment, as well as design of experiments investigating live-cell response using more reliable physical models. Second, the data obtained experimentally will be available …

Longissimus Muscle Fatigue And Injury Response Due To Electrical Stimulation With Varied Work/Rest Ratios, Peter Wawrow

Wayne State University Dissertations

LONGISSIMUS MUSCLE FATIGUE AND INJURY RESPONSE DUE TO ELECTRICAL STIMULATION WITH VARIED WORK/REST RATIOS

BY

PETER WAWROW

May 2011

Advisor: John Cavanaugh, MD

Major: Biomedical Engineering

Degree: Doctor of Philosophy

The estimated yearly cost of lost-time work injuries and illnesses is $140 billion. The average cost of musculoskeletal disorders (MSDs) exceeds all other claims. These injuries persist in spite of ergonomic interventions addressing known risk factors. Work/rest ratios have not received a significant amount of attention, particularly in low back disorders, and it is hypothesized that the lack of adequate rest within a work cycle may contribute to muscle fatigue …

A Multi-Species Analysis Of Biomechanical Responses Of The Head To A Shock Wave, Richard Bolander

Wayne State University Dissertations

Shock wave induced brain injury remains a field of research that has great consequences for the rehabilitation of soldiers and civilians that are exposed to an explosion. As such, for the research to be successful in developing strategies to mitigate the effects of these injuries, appropriate research methods need to be developed. Animal models are currently employed to understand the brain's response to a shock wave exposure. Unfortunately no criteria have been established that indicates in what way the mechanical inputs that the cells in an animal's brain are subjected to are similar to a human. The purpose of this …

Processing Random Signals In Neuroscience, Electrical Engineering And Operations Research, Kalyan Raman

Wayne State University Dissertations

The topic of this dissertation is the study of noise in electrical engineering, neuroscience, biomedical engineering, and operations research through mathematical models that describe, explain, predict and control dynamic phenomena. Noise is modeled through Brownian Motion and the research problems are mathematically addressed by different versions of a generalized Langevin equation. Our mathematical models utilize stochastic differential equations (SDEs) and stochastic optimal control, both of which were born in the soil of electrical engineering. Central to this dissertation is a brain-physics based model of cerebrospinal fluid (CSF) dynamics, whose structure is fundamentally determined by an electrical circuit analogy. Our general …

On The Real-Time Performance, Robustness And Accuracy Of Medical Image Non-Rigid Registration, Yixun Liu

Dissertations, Theses, and Masters Projects

Three critical issues about medical image non-rigid registration are performance, robustness and accuracy. A registration method, which is capable of responding timely with an accurate alignment, robust against the variation of the image intensity and the missing data, is desirable for its clinical use. This work addresses all three of these issues. Unacceptable execution time of Non-rigid registration (NRR) often presents a major obstacle to its routine clinical use. We present a hybrid data partitioning method to parallelize a NRR method on a cooperative architecture, which enables us to get closer to the goal: accelerating using architecture rather than designing …

Development Of An Approach To Increase Drug Uptake To Bone Tumors Using Non-Invasive Mechanical Loading, Paolo E. Palacio

Dissertations and Theses

This thesis develops an approach to enhance drug delivery to bone tumors by implementing a non-invasive mechanical loading technique. An imaging protocol that characterizes the load-enhanced drug uptake is also presented. The long-term goal of this work is to develop a clinical protocol that enhances the delivery of therapeutic agents to bone tumors by utilizing load-bearing activity. This easy-to-implement approach could help increase drug uptake into the tumor interstitial fluid space as well as into tumor cells, thereby enhancing a drug's clinical effect while decreasing systemic drug dosage and unwanted side effects. This thesis details the process used to grow …

Proteomic Analysis Of Human Mesenchymal Stem Cell Aging During Serial Sub-Culture, Pawan Kc

Dissertations and Theses

"Human mesenchymal stem cells (hMSCs) hold great potential for clinical applications in regenerative medicine. However, hMSCs occur at a very low frequency in bone marrow so the clinical use as cellular therapeutics requires suitable techniques for isolation and expansion. Furthermore, these cells can be expanded in vitro for only limited passage numbers before they reach a senescent state. Previous studies have shown that long term culture of hMSCs results in the decrease in proliferation rates, changes in genomic expressions, increase in cell sizes, and other morphological changes. Currently the mechanisms of hMSC aging and biomarkers associated with it have not …

Characterization Of Bioreactor System For Tissue Engineered Blood Vessels, Kasim Shah

Biomedical Engineering

No abstract provided.

Issues On Clean Diesel Combustion Technology Using Supercritical Fluids: Thermophysical Properties And Thermal Stability Of Diesel Fuel, Ronghong Lin

Biomedical and Chemical Engineering - Dissertations

The clean diesel combustion technology using supercritical fluids is aimed to both improve fuel economy and reduce harmful emissions. This novel process involves preparation, injection and combustion of supercritical fuel/diluents mixtures. Design and development of this new process require a deep understanding of fuel properties. The current study has attempted to address three fuel property related issues: fuel surrogates, diffusivity and thermal stability.

Fuel surrogates are often used in engine research to mimic real fuel properties. In this work, ten diesel fuel surrogates were investigated, and the ability of these surrogates to predict diesel fuel properties was evaluated. It was …

Quantitative Computed-Tomography Based Bone-Strength Indicators For The Identification Of Low Bone-Strength Individuals In A Clinical Environment, Bino Abel Varghese

Browse all Theses and Dissertations

The aim of the current study was to develop quantitative computed-tomography (QCT)-based bone-strength indicators that highly correlate with finite-element (FE)-based strength. We perform a combined numerical-experimental study, comparing FE-predicted surface strains with strain gauge measurements, to validate the FE models of 36 long bones (humerus, radius, femur and tibia) under three-point bending and torsion. The FE models were constructed from trans-axial volumetric CT scans, and the segmented bone images were corrected for partial-volume effects. The material properties (Young's modulus for cortex, density-modulus relationship for trabecular bone and Poisson's ratio) were calibrated by minimizing the error between experiments and simulations among …

Predicting Vigilance Performance Under Transcranial Direct Current Stimulation, Nathaniel Reese Bridges

Browse all Theses and Dissertations

A brain stimulation technology called transcranial direct current stimulation (tDCS) may potentially mitigate the vigilance decrement. To practically use such technology, however, a model is necessary that indicates vigilance performance, both when stimulation is being applied and not applied. To address this issue, the author developed models capable of predicting vigilance performance in real and control stimulation conditions using previous tDCS-study data. The "all possible combinations" regression method produced over 200 models, later screened to 10. The model with the best average %error (11.49 ± 0.10) used left hemispheric cerebral blood flow velocity (CBFVL) as its sole input term-accounting for …

A Secure Behavior Modification Sensor System For Physical Activity Improvement, Alan Price

CGU Theses & Dissertations

Today, advances in wireless sensor networks are making it possible to capture large amounts of information about a person and their interaction within their home environment. However, what is missing is how to ensure the security of the collected data and its use to alter human behavior for positive benefit.

In this research, exploration was conducted involving the "infrastructure" and "intelligence" aspects of a wireless sensor network through a Behavior Modification Sensor System. First was to understand how a secure wireless sensor network could be established through the symmetric distribution of keys (the securing of the infrastructure), and it involves …

Exploring The Potential Of Inkjet Printing For The Fabrication Of Tissue Test Systems, Vidya Seshadri

All Theses

Animal models and two-dimensional assays involved in drug testing, vaccine development and basic scientific discovery are not an accurate representation of the human body; hence there is a need to develop new bench top methodologies which are better suited to yield information about in vivo behavior. There is a paucity of reliable in vitro-derived information regarding the reasons for the cause and progression of diseases. These concerns have lead to the development of three-dimensional systems which can facilitate improved understanding of disease etiology and also can bridge the path to the clinic.
The long term goal, beyond the scope of …

Aberrant Dna Replication At An Ectopic Chromosomal Site In Human Cells, Xiaomi Chen

Browse all Theses and Dissertations

Aberrant DNA replication, including over-replication or under-replication may lead to life-threatening mutation or even cause human diseases. This thesis focused on three issues related to abnormal DNA replication in human chromosomes including: I) to define the function of DNA unwinding element (DUE) and DNA unwinding element-binding protein (DUE-B) to maintain an active c-myc replicator; II) to determine the role of trans-acting factors in defining a replication origin on human chromosomes; III) to investigate the mechanism by which hairpins affect DNA replication and instability of (CTG)n•(CAG)n trinucleotide repeat tracts in human cells.

Our laboratory previously demonstrated that both DUE and DUE-B, …

Influence Of Design Parameters On Cup-Stem Orientations For Impingement Free Range Of Motion In Hip Implants, Dishita Prakashbhai Patel

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The objective of this investigation is to determine the optimum positions of the prosthesis in total hip arthroplasty that produce least amount of impingement. Theoretical ranges of six basic hip motions were determined under walking, stumbling, internal rotation at 90 flexion and external rotation at 0 extension with 15 abduction, using mathematical models and validated for impingement using finite element analysis. A generalized approach, where impingement does not occur, was developed in this study to understand influence of design parameters such as head-neck ratio, neck-shaft angle, oscillation angle, and stem offset on cup-stem orientations such as cup inclination, cup anteversion, …

A Probabilistic Assessment Of Vertebral Cortical Bone Fracture Of Intraosteonal Structures, Isaac Graham Mabe

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Cortical bone is a porous structure. The presence of these pores creates the possibility of a local overstressed area that has the likelihood of premature failure. Some failure modes of the vertebral endplates, for example subsidence which occurs at rates as high as 77 percent, can be better predicted with further understanding of failure mechanisms and the ability to predict those mechanisms. A probabilistic assessment of the pore size and its contribution to the fracture toughness has not been investigated in the cortical shell of the vertebral endplates. This research develops a probabilistic model that has the ability to determine …

Anthropometric Analysis Of The Cervical Spine, Susan Hueston

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An understanding of the dimensional anatomy of the cervical spine is necessary in order to help diagnose disease, deformity, injury, and device development. Previous investigation has been completed utilizing cadavers, X-rays and other imaging techniques. This research utilized computer tomography images from the trauma registry at Miami Valley Hospital in Dayton, Ohio to complete an anthropometric study of the cervical spine. Linear mathematical models were developed to investigate the relationships present in the dimensional anatomy of the cervical spine. New measurements were completed on subjects of both Caucasian and African American descent and of both genders. An approximation of the …

Investigation Of Variability In Cognitive State Assessment Based On Electroencephalogram-Derived Features, Samantha Lokelani Crossen

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To implement adaptive aiding in modern aviation systems there is a need for accurate and reliable classification of cognitive workload. Using electroencephalogram (EEG)-derived features, it has been reported that an Artificial Neural Network (ANN) can achieve 95% or higher classification accuracy on the same day for an individual operator, but only 70% or less on a different day. To gain a further insight into this discrepancy, data from a previous study was utilized to study the classification variability. The EEG-derived features were first calculated by spectral power estimation. The variability was then analyzed by performing cognitive workload classification in which …

Selective Automatic Image Feature Detection, Aijing Wang

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To allow automatic assessment of computed tomography (CT) images of long bones, the identification of the location of regions of interest is important. The distance between the distal and proximal styloids may act as reference points for bone length; however, the locations of the distal and proximal growth plates represent further important reference features. The current methods to locate these feature positions are manual. In this project, we attempt to find these feature positions automatically.

A CT data set was split into two subsets, a development set, and a validation set. We first extracted basic information from the stack and …

Impact Of Insulin Resistance On Behavioral And Neurochemical Deficits In Db/Db Mice, Ajaykumar Narayan Sharma

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There is a high comorbidity of type-2 diabetes and neuropsychiatric disorders. However, there is paucity of preclinical research to study this phenomenon. The validity of the db/db mouse as an animal model to study type-2 diabetes and related macrovascular and microvascular complications is well established. The first part of this dissertation was designed to investigate comprehensively the db/db mouse behavior as preclinical evidence of type-2 diabetes related major neurobehavioral complications. Juvenile (5-6 weeks) and adult (10-11 weeks) db/db mice were screened for behavioral depression in forced swim test (FST), psychosis-like symptoms using pre-pulse inhibition (PPI) test, anxiety behavior employing elevated …

Son Is Essential For Nuclear Speckle Organization, Cell Cycle Progression And Pre-Mrna Splicing, Alok S. Sharma

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Nuclear speckles provide important spatial organization and dynamic regulation for pre-mRNA processing factors in mammalian cells. While the nuclear speckle proteome is complex, little is known at the molecular level about how these factors are organized into nuclear speckles or how alterations in the organization of these factors impacts gene expression. We have discovered a new function for a large (2564 amino acid) nuclear speckle protein called Son in maintaining the organization of pre-mRNA processing factors in nuclear speckles. Depletion of Son by RNAi causes snRNP and serine-arginine rich (SR protein) splicing factors to undergo dramatic disorganization into doughnut-shaped nuclear …

The Development Of Silver Nanoparticles As Antiviral Agents, John Christopher Trefry

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Silver nanoparticles (AgNPs) have received tremendous attention for their antimicrobial properties; however, many gaps in knowledge exist. To address these issues, three research objectives were examined. The first objective hypothesized AgNPs can be size selected and concentrated via tangential flow ultrafiltration. The second objective hypothesized a high-throughput method could be developed to screen nanoparticle antiviral-activity and cytotoxicity simultaneously. The third objective hypothesized AgNPs inhibit viruses by preventing viral entry.

For objective one, a tangential flow ultrafiltration scheme was tested on AgNPs synthesized via the Creighton Colloid method. AgNPs were analyzed via transmission electron microscopy. In objective two, an HIV-1 vector …

Semi-Automated Dental Cast Analysis Software, Mathew Thomas

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Dental casts have been used extensively to study almost all aspects of the human dentition. These aspects varied from the study of tooth form and morphology, inheritance and genetics, growth and development, occlusion, arch alignment and crowding to mathematical determination of dental arch form.

The aim of this project was to develop a tool to semi-automate the measurement of dental casts that would be precise, accurate and efficient. Measurements include tooth widths, arch lengths and widths, angle of rotation and crown area for each tooth.

The task was divided into two different parts: first, the development of semi-automatic software to …

Cervical Spine Biomechanical Behavior And Injury, Mbulelo T. Makola

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A finite element model of the cervical spine including the C2 through C7 levels was developed in order to study the behavior of the cervical spine region. The model was validated in flexion extension, bending, and rotational load scenarios. The model was found to represent the biomechanical behavior of the cervical spine. The validated cervical spine finite element model was used to study spinal injury and disease processes. The model provided qualitative estimates of load carrying and stress distribution as well as range of motion.