Engineering Commons^™

Implementation Of A Pain Generator Controlled By Pressure And Feasability In Its Applications For Functional Near-Infrared Spectroscopy, Pamela Agwa Tebebi

Bioengineering Theses - Archive

Pain is a sensory and emotional experience as a result of possible or definite tissue damage. The level of pain is subjective to the individual's consciousness of sensory stimuli. Pain stimuli can be noxious (i.e., potentially damaging) or innocuous (i.e., normally not painful). Therefore, pain perception can be based on the degree of the stimuli. Studies have been done using brain imaging modalities to assess pain. Functional Near-infrared spectroscopy (fNIRS) is a noninvasive imaging tool and has been used to study the hemodynamic variations in the brain induced by a variety of activations. This research was a feasibility study to …

Investigation Of Brain Activity In Prefrontal Cortex Under Noxious Pain Stimuli And During Psychological Test Using Functional Near Infrared Spectroscopy, Sabin Khadka

Bioengineering Theses - Archive

Functional Near Infrared Spectroscopy (fNIRS) is a non-invasive functional neuroimaging technique, which measures changes in oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) concentrations based on the principle of near infrared spectroscopy. For my thesis, I have utilized fNIRS in the prefrontal regions to study cognitive functions under noxious pain and during a psychological test. The fNIRS signals were acquired from the prefrontal cortex (PFC) in order to investigate the hemodynamic response under noxious pain stimuli. The measurement consisted of two different visits separated by seven to ten days with two different levels of pain intensity. From the observations, PFC shows significant deactivation …

Evaluation Of Spatial Resolution And Localization Accuracy Of Absorbing Heterogenity Embedded In Homogenous And Layered Turbid Media Using Functional Near Infrared Spectroscopy, Niranjana Nandakumar

Bioengineering Theses - Archive

Functional Near-Infrared Spectroscopy (fNIRS) is a non-invasive widely used technique for imaging the brain activation patterns in the cerebral cortex of neonates and adults. For the fNIRS imaging of these brain activation patterns, it is common to assume the head geometry as a homogenous medium due to the resulting computational simplicity of the image reconstruction problem. In reality the head is not a simple homogenous medium and prior research has been conducted to show that light propagates differently in a spatially heterogeneous model of the head compared to a homogenous one, which alters the sensitivity of NIR light detection on …

A Multimodality Dlp® Imaging System For Clinical Surgery, Michael Lee Mangum

Bioengineering Theses - Archive

With 1.38 million new cases and 450,000 deaths worldwide due to breast cancer, there is a clear need for safe and complete surgical intervention for the treatment of breast cancer. Imaging solutions have been created and developed to help plastic surgeons during breast reconstructive surgery. However, these solutions were implemented separately depending on their particular modality, which can result in higher costs for hospital and patient use. The digital micromirror device (DMD) developed by Texas Instruments has been shown to exhibit spectral control of light at a digital level, and could theoretically allow for the incorporation of multiple imaging modalities …

Three-Dimensional Multimedium Computational Model For Drug Delivery Using Finite Element Analysis, Eduardo Martinez

Bioengineering Theses - Archive

Approximately 2.8% of trauma patients present peripheral nerve injury, which can result in loss of motor function. Current strategies for peripheral nerve repair had focused on the development of synthetic nerve conduits that provide physical guidance. One advantage of the synthetic nerve conduits is that the conduit can be utilize as a delivery system and gain the ability to deliver neurotrophic factors, which have an effect on controlling the survival, migration, proliferation, and differentiation of different neural cell types. Currently there is no method to quantify the concentration of growth factors in the nerve conduit during the implantation time. In …

Estimation Of The Centre Of Mass From Motion Capture And Force Plate Recordings: A Study On The Elderly, Sebastien Cotton, Michele Vanoncini, Philippe Fraisse, Nacim Ramdani, Emel Demircan, Andrew P. Murray, Thierry Keller

Mechanical and Aerospace Engineering Faculty Publications

The estimation of the centre of mass position in humans is usually based on biomechanical models developed from anthropometric tables. This method can potentially introduce errors in studies involving elderly people, since the ageing process is typically associated with a modification of the distribution of the body mass. In this paper, an alternative technique is proposed, and evaluated with an experimental study on 9 elderly volunteers. The technique is based on a virtual chain, identified from experimental data and locating the subject's centre of mass. Its configuration defines the location of the centre of mass, and is a function of …

Arteriogenesis And Ischemia Impair Functional Vasodilation In Resistance Arteries, Trevor Cardinal, Joseph S. Zhu, Kyle R. Struthers, Thomas J. Kesler, Matthew D. Yocum

Biomedical Engineering

No abstract provided.

Arterial Tissue Perforation Using Ultrasonically Vibrating Wire Waveguides, Mark Wylie

Doctoral

Chronic Total Occlusions (CTOs) are fibrous and calcified atherosclerotic lesions which completely occlude the artery. They are difficult to treat with standard dilation procedures as they cannot be traversed easily. Their treatment is also associated with a high risk of arterial perforation. Low frequency ultrasonic vibrations delivered via wire waveguides represent a minimally invasive treatment for CTOs and other tissue ablation applications. These devices typically operate at 20–50 kHz delivering wire waveguide distal tip amplitudes of vibration of 0-60 μm. The diseased tissue is ablated or disrupted by repetitive direct mechanical contact and cavitation. This research assesses the susceptibility of …

Sensory Motor Remapping Of Space In Human-Machine Interfaces, Ferdinando A. Mussa-Ivaldi, Maura Casadio, Zachary C. Danziger, Kristine M. Mosier, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Studies of adaptation to patterns of deterministic forces have revealed the ability of the motor control system to form and use predictive representations of the environment. These studies have also pointed out that adaptation to novel dynamics is aimed at preserving the trajectories of a controlled endpoint, either the hand of a subject or a transported object. We review some of these experiments and present more recent studies aimed at understanding how the motor system forms representations of the physical space in which actions take place. An extensive line of investigations in visual information processing has dealt with the issue …

Energy Deposition In The Breast During Ct Scanning: Quantification And Implications For Dose Reduction, Franco Rupcich, Iacovos Kyprianou, Andreu Badal, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Studies suggest that dose to the breast leads to a higher lifetime attributable cancer incidence risk from a chest CT scan for women compared to men. Numerous methods have been proposed for reducing dose to the breast during CT scanning, including bismuth shielding, tube current modulation, partial-angular scanning, and reduced kVp. These methods differ in how they alter the spectrum and fluence across projection angle. This study used Monte Carlo CT simulations of a voxelized female phantom to investigate the energy (dose) deposition in the breast as a function of both photon energy and projection angle. The resulting dose deposition …

Visual And Proprioceptive Contributions To Compensatory And Pursuit Tracking Movements In Humans, Megan L. Heenan, Robert A. Scheidt, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

An ongoing debate in the field of motor control considers how the brain uses sensory information to guide the formation of motor commands to regulate movement accuracy. Recent research has shown that the brain may use visual and proprioceptive information differently for stabilization of limb posture (compensatory movements) and for controlling goal-directed limb trajectory (pursuit movements). Using a series of five experiments and linear systems identification techniques, we modeled and estimated the sensorimotor control parameters that characterize the human motor response to kinematic performance errors during continuous compensatory and pursuit tracking tasks. Our findings further support the idea that pursuit …

A Quantitative And Standardized Robotic Method For The Evaluation Of Arm Proprioception After Stroke, Lucia Simo, Claude Ghez, Lior Botzer, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Stroke often results in both motor and sensory deficits, which may interact in the manifested functional impairment. Proprioception is known to play important roles in the planning and control of limb posture and movement; however, the impact of proprioceptive deficits on motor function has been difficult to elucidate due in part to the qualitative nature of available clinical tests. We present a quantitative and standardized method for evaluating proprioception in tasks directly relevant to those used to assess motor function. Using a robotic manipulandum that exerted controlled displacements of the hand, stroke participants were evaluated, and compared with a control …

Modeling And Quantitative Analysis Of White Matter Fiber Tracts In Diffusion Tensor Imaging, Xuwei Liang

University of Kentucky Doctoral Dissertations

Diffusion tensor imaging (DTI) is a structural magnetic resonance imaging (MRI) technique to record incoherent motion of water molecules and has been used to detect micro structural white matter alterations in clinical studies to explore certain brain disorders. A variety of DTI based techniques for detecting brain disorders and facilitating clinical group analysis have been developed in the past few years. However, there are two crucial issues that have great impacts on the performance of those algorithms. One is that brain neural pathways appear in complicated 3D structures which are inappropriate and inaccurate to be approximated by simple 2D structures, …

The Effect Of Practice On Eye Movements In The 1/D Paradigm, Will Seidelman

University of Kentucky Master's Theses

Previous studies have demonstrated that observers may ignore highly salient feature singletons during a conjunction search task through focusing the attentional window (Belopolsky, Zwaan, Theeuwes, & Kramer, 2007), or by the suppression of bottom-up information (Treisman & Sato, 1990). In the current study, observers’ eye movements were monitored while performing a search task in which a feature singleton was present and corresponded with the target at a chance level. With practice, observers were less likely to make an initial saccade toward the singleton item, but initial saccades directed at the target were likely throughout. Results demonstrate that, in an effort …

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

Browse all Theses and Dissertations

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 Validation Of A Prototype Dry Electrode System For Electroencephalography, Jason Monnin

Browse all Theses and Dissertations

Current physiologically-driven operator cognitive state assessment technology relies primarily on electroencephalographic (EEG) signals. Traditionally, gel-based electrodes have been used; however, the application of gel-based electrodes on the scalp requires expertise and a considerable amount of preparation time. Additionally, discomfort can occur from the abrasion of the scalp during preparation, and the electrolyte will also begin to dry out over extended periods of time. These drawbacks have hindered the transition of operator state assessment technology into an operational environment. QUASAR, Inc., (San Diego, CA) has developed a prototype dry electrode system for electroencephalography that requires minimal preparation. A comparison of the …

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 …

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 …

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 …

Computational Analyses Of The Uptake And Distribution Of Carbon Monoxide (Co) In Human Subjects, Kinnera Chada

University of Kentucky Doctoral Dissertations

Carbon monoxide (CO) is an odorless, colorless, tasteless gas that binds to hemoglobin with high affinity. This property underlies the use of low doses of CO to determine hemoglobin mass (M_Hb) in the fields of clinical and sports medicine. However, hemoglobin bound to CO is unable to transport oxygen and exposure to high CO concentrations is a significant environmental and occupational health concern. These contrasting aspects of CO—clinically useful in low doses but potentially lethal in higher doses—mandates a need for a quantitative understanding of the temporal profiles of the uptake and distribution of CO …

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 …

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, …

V1-Derived Renshaw Cells And Ia Inhibitory Interneurons Differentiate Early During Development, Ana Benito González

Browse all Theses and Dissertations

Locomotor development is dependent on the maturation of spinal cord circuits controlling motor output, but little is known about the development of the spinal interneurons that control motoneuron activity. This study focused on the development of Renshaw cells (RCs) and Ia inhibitory interneurons (IaINs), which mediate recurrent and reciprocal inhibition, respectively, two basic inhibitory circuits for motorneuron control. Both interneurons originate from the same progenitor pool (p1) giving rise to ventral spinal embryonic interneurons denominated V1. V1-derived interneurons (V1-INs) establish local inhibitory connections with ipsilateral motoneurons and express the transcription factor engrailed-1. This characteristic permitted the generation of transgenic mice …

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

Browse all Theses and Dissertations

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

Browse all Theses and Dissertations

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

Browse all Theses and Dissertations

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

Browse all Theses and Dissertations

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

Browse all Theses and Dissertations

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 …

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

Browse all Theses and Dissertations

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 …

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

Browse all Theses and Dissertations

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 …