Biomedical Engineering and Bioengineering Commons^™

Biomechanical Modeling Of Pediatric Clubfoot, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

3d Micron-Scale Imaging Of The Cortical Bone Canal Network In Human Osteogenesis Imperfecta (Oi), John R. Jameson, Carolyne Albert, Bjoern Busse, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Osteogenesis imperfecta (OI) is a genetic disorder leading to increased bone fragility. Recent work has shown that the hierarchical structure of bone plays an important role in determining its mechanical properties and resistance to fracture. The current study represents one of the first attempts to characterize the 3D structure and composition of cortical bone in OI at the micron-scale. A total of 26 pediatric bone fragments from 18 individuals were collected during autopsy (N_c=5) or routing orthopaedic procedures (N_OI=13) and imaged by microtomography with a synchrotron light source (SRµCT) for several microstructural parameters including cortical porosity …

Visuomotor Learning Enhanced By Augmenting Instantaneous Trajectory Error Feedback During Reaching, James L. Patton, John Wei Yejun, Preeti Bajaj, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

We studied reach adaptation to a 30u visuomotor rotation to determine whether augmented error feedback can promote faster and more complete motor learning. Four groups of healthy adults reached with their unseen arm to visual targets surrounding a central starting point. A manipulandum tracked hand motion and projected a cursor onto a display immediately above the horizontal plane of movement. For one group, deviations from the ideal movement were amplified with a gain of 2 whereas another group experienced a gain of 3.1. The third group experienced an offset equal to the average error seen in the initial perturbations, while …

Comparison Of Randomized Multifocal Mapping And Temporal Phase Mapping Of Visual Cortex For Clinical Use, Yan Ma, B. Douglas Ward, Kristina M. Ropella, Edgar A. Deyoe

Biomedical Engineering Faculty Research and Publications

fMRI is becoming an important clinical tool for planning and guidance of surgery to treat brain tumors, arteriovenous malformations, and epileptic foci. For visual cortex mapping, the most popular paradigm by far is temporal phase mapping, although random multifocal stimulation paradigms have drawn increased attention due to their ability to identify complex response fields and their random properties. In this study we directly compared temporal phase and multifocal vision mapping paradigms with respect to clinically relevant factors including: time efficiency, mapping completeness, and the effects of noise. Randomized, multifocal mapping accurately decomposed the response of single voxels to multiple stimulus …

Cpg And Interleukin-15 Synergize To Enhance Ifn-Gamma Production By Activated Cd8(+) T Cells, Dustin Cobb, Sigi Guo, Ronald B. Smeltz

Bioelectrics Publications

Interleukin-15 (IL-15) regulates the development and maintenance of memory CD8(+) T cells. Paradoxically, we previously reported that IL-15 could enhance CD8(+) T-cell responses to IL-12, a proinflammatory cytokine required for optimal priming of effector CD8(+) T cells. To expand the physiological relevance of these findings, we tested IL-15 for its ability to enhance T-cell responses to bacterial CpG. Expectedly, CpG enhanced the production of IFN-gamma by CD8(+) T cells polyclonally activated with anti-CD3. However, addition of IL-15 to CpG-stimulated cultures led to a striking increase in IFN-gamma production. The effect of CpG and IL-15 was also evident with CD8(+) T …

Response To "Sodium Current Inhibition By Nanosecond Pulsed Electric Field (Nspef) - Fact Or Artifact?" By Verkerk Et Al, Andrei G. Pakhomov

Bioelectrics Publications

It was nice to learn that our studies of nanosecond pulsed electric field (nsPEF) effects on membrane currents [Nesin et al., 2012; Nesin and Pakhomov, 2012] gained the attention of scientists outside the immediate field of bioelectromagnetics.

An Empirical Muscle Intracellular Action Potential Model With Multiple Erlang Probability Density Functions Based On A Modified Newton Method, Gyutae Kim, Mohammed M. Ferdjallah, Frederic D. Mckenzie

Computational Modeling & Simulation Engineering Faculty Publications

The convolution of the transmembrane current of an excitable cell and a weighting function generates a single fiber action potential (SFAP) model by using the volume conductor theory. Here, we propose an empirical muscle IAP model with multiple Erlang probability density functions (PDFs) based on a modified Newton method. In addition, we generate SFAPs based on our IAP model and referent sources, and use the peak-to-peak ratios (PPRs) of SFAPs for model verification. Through this verification, we find that the relation between an IAP profile and the PPR of its SFAP is consistent with some previous studies, and our IAP …

Bone Properties By Nanoindentation In Mild And Severe Osteogenesis Imperfecta, Carolyne Albert, John Jameson, Jeffrey M. Toth, Peter Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Background

Osteogenesis imperfecta is a heterogeneous genetic disorder characterized by bone fragility. Previous research suggests that impaired collagen network and abnormal mineralization affect bone tissue properties, however, little data is yet available to describe bone material properties in individuals with this disorder. Bone material properties have not been characterized in individuals with the most common form of osteogenesis imperfecta, type I.

Methods

Bone tissue elastic modulus and hardness were measured by nanoindentation in eleven osteotomy specimens that were harvested from children with osteogenesis imperfecta during routine surgeries. These properties were compared between osteogenesis imperfecta types I (mild, n = …

A Novel Resistance Exercise Machine For Use In A Lower Body Negative Pressure Box To Counteract The Effects Of Weightlessness, Christine M. Dailey

Doctoral Dissertations and Master's Theses

Physiological deconditioning is a critical problem in space, especially during long-term missions. Resistance exercise coupled with lower body negative pressure (LBNP) has been shown to be effective in counteracting some of the deconditioning related problems. This thesis describes the development of a compact and effective resistance exercise machine that works within an existing environmentally controlled LBNP Box and is designed to simulate both exercise and sitting, to prevent microgravity-induced deconditioning by simulating physiological and biomechanical features of upright exercise and daily activities. Theoretical calculations are carried out to determine whether kinematics, musculoskeletal loadings, and metabolic rate during supine exercise within …

Imaging Iron Content In Patients With Multiple Sclerosis Using Magnetic Resonance Imaging, Charbel Abdo Habib

Wayne State University Dissertations

The importance of iron in maintaining normal physiological processes in the human body has been well emphasized in the literature. However, "when iron behaves badly", its abnormal presence might lead to a spectrum of pathologies depending on what function has been altered. In the brain, for instance, abnormal iron content is thought to be associated with neurodegenerative diseases. In this dissertation, we study iron involvement in one of the most debilitating neurological diseases, multiple sclerosis (MS), using in vivo magnetic resonance imaging. We first test the sensitivity and specificity of the MR method used, known as susceptibility weighted imaging (SWI) …

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 …

Cervical Spine Tolerance And Response In Compressive Loading Modes Including Combined Compression And Lateral Bending, Daniel Toomey

Wayne State University Dissertations

Injuries in motor vehicle accidents continue to be a serious and costly societal problem. Automotive safety researchers have observed noticeable lateral bending of the anthropomorphic test device (ATD) neck prior to or in conjunction with head impact with the vehicle roof in rollover crash tests. Since there is scant data available about the effects of lateral bending on overall compressive tolerance of the human cervical spine, it is unknown if the presence of lateral bending is important to consider during impacts with the apex of the head. Compressive injury tolerance has historically been reported by identifying the axial force at …

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 …

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 …

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 …

Functional Near Infrared Detection Of Real And Imagined Finger Taps Using Support Vector Machine, Linear Discriminant Analysis, And Decision Tree Classification Methods, Eugene A. Stoudenmire

Computational Modeling & Simulation Engineering Theses & Dissertations

This study investigates the thesis that given cerebral response samples of an individual's left, right, both, and imagined finger tapping, continuous wave (CW) functional Near Infrared (fNIR), unregistered with fMRI, can differentiate between any two of the four categories.

Fifty subjects were outfitted with a single source/detector attached to a single, square pad, affixed to their heads using devices such as elastic bands and caps for light shielding. Slides depicting arrows pointing left, right, both directions, or made of dashed lines were presented to each subject, with a slide of text interspersed between each. Subjects tapped with their left finger, …

Biomechanical Comparison Of Lower Limb Unloading Between Common Modalities Of Ankle Foot Orthoses, Andrea Blake Wanamaker

Electronic Theses and Dissertations

Tibial stress fractures and other lower extremity injuries can be treated using an ankle foot orthosis (AFO). AFOs are popular because they allow the patient to ambulate somewhat naturally while reducing weight bearing on the injured limb. Despite their popularity, it is currently unclear how well AFOs reduce lower extremity weight bearing.

The first objective of this investigation was to examine the ability of three commonly used ankle foot orthoses to reduce weight bearing within the lower limb by comparing the ground reaction force measured from a force platform to the force measured from an insole pressure measurement device inside …

Computational Representation Of The Patellofemoral Joint, Abraham Wright

Electronic Theses and Dissertations

Many people suffer from knee pain due to abnormal function of the patellofemoral joint and are not able to enjoy normal activities of daily living. Surgical treatments are available and new methods are being developed by the medical industry. However, computational tools to efficiently evaluate the effects of the intervention on patellofemoral function are lacking.

Therefore, a validated and efficient computational model of the patellofemoral joint was developed. The subject specific finite element model was validated against the patellar kinematics recorded during cadaveric patellofemoral laxity experiments of the natural knee. The development involved a sequential process in which the soft-tissue …

Representing Intersubject Variability With A Statistical Shape And Alignment Model Of The Knee, Chandreshwar Rao

Electronic Theses and Dissertations

Prior statistical shape models have not considered multiple structures in the knee joint to characterize anatomic variation which are required to investigate joint mechanics further for the successful knee replacement. Accordingly, the study's objective was to develop statistical shape and alignment model (SSAM) to capture intersubject variability and demonstrate the ability to generate realistic instances for use in finite element analysis (FEA). SSAM described the variability in the training set of 20 subjects with a series of modes of variation obtained by performing principal component analysis (PCA). PCA produced modes of variation with the first 3 modes representing 70% and …

A Novel Biomaterial Enables Chemotactic Study Of Motile Central Nervous System-Derived Tumor Cells, Tanya Singh

Dissertations and Theses

"The local cell microenvironment plays an important role in maintaining the dynamics of the extracellular matrix (ECM) and the cell-ECM relationship. ECM is a complex network of macromolecules with distinct mechanical and biochemical characteristics [1]. The multifaceted interactions that occur between cells and the ECM are crucial to the regulation of processes that maintain homeostasis. These mechanisms are often deregulated during cancer onset and progression, which cause the ECM to become highly disorganized, alter the cell-matrix interactions, and promote increased hypervascularity and metastasis as these components are indicative of cancer progression. Medulloblastoma (MB) is one of the most common, malignant …

Design, Product Development And Risk Assessment Of Tin (Sn) Ring Electrodes As A Substitute To Silver-Silver Chloride (Ag Agci) Ring Electrodes For High Definition Transcranial Direct Current Stimulation (Hd-Tdcs), Linford Leitch

Dissertations and Theses

The objective of this research thesis is to test the viability of Tin (Sn) ring electrodes as an inexpensive alternative to sintered Silver-Silver Chloride (Ag|AgCl) ring electrodes for High Definition – transcranial Direct Current Stimulation (HD-tDCS). Throughout our initial bench top testing of tin electrodes in combination with a ‘conductive electrode gel’, the passing of a 2mA direct current on agar block showed the formation of white cloud around the anode electrode and a cluster of air bubbles on the cathode. The analysis of pertinent literature indicates that the white milky substance produced during the stimulation at the anode is …

Design, Implementation, And Performance Study Of An Open Source Eye-Control System To Pilot A Parrot Ar.Drone Quadrocopter, John M. Ettikkalayil

Dissertations and Theses

Natural user interface is a fairly new concept in the field of human-computer interaction. It is the idea of using every day natural human behaviors and actions to control a device. An example of a natural user interface is touch control technology in smartphones, tablets, and new laptops. The interaction is more direct when compared to artificial input devices like a keyboard and mouse. Though natural user interface devices might not perform as well as standard input devices for certain applications, for other applications they are now the de facto standard. A new user interface that is poised to be …

Finite Element Study Of Transcranial Direct Current Stimulation: Customization Of Models And Montages, Dennis Q. Truong

Dissertations and Theses

Transcranial Direct Current Stimulation (tDCS) is a non-invasive neuromodulation technique that applies low amplitude current via electrodes placed on the scalp. Rather than directly eliciting a neuronal response, tDCS is believed to modulate excitability – encouraging or suppressing activity in regions of the brain depending on the polarity of stimulation. The particular application of tDCS is often determined by the electrode configuration and intensity of stimulation. MRI-derived finite element models have been developed to analyze the effect of these parameters allowing novel electrode configurations to be tested in subject specific models. By creating a subject specific model of an obese …

Systematic Genomic Identification Of Colorectal Cancer Genes Delineating Advanced From Early Clinical Stage, Hojoon Lee, Patrick Flaherty, Hanlee P. Ji

Mathematics and Statistics Department Faculty Publication Series

Background: Colorectal cancer is the third leading cause of cancer deaths in the United States. The initial assessment of colorectal cancer involves clinical staging that takes into account the extent of primary tumor invasion, determining the number of lymph nodes with metastatic cancer and the identification of metastatic sites in other organs. Advanced clinical stage indicates metastatic cancer, either in regional lymph nodes or in distant organs. While the genomic and genetic basis of colorectal cancer has been elucidated to some degree, less is known about the identity of specific cancer genes that are associated with advanced clinical stage and …

Rvd: A Command-Line Program For Ultrasensitive Rare Single Nucleotide Variant Detection Using Targeted Next-Generation Dna Resequencing, Anna Cushing, Patrick Flaherty, Erik Hopmans, John M. Bell, Hanlee P. Ji

Mathematics and Statistics Department Faculty Publication Series

Background: Rare single nucleotide variants play an important role in genetic diversity and heterogeneity of specific human disease. For example, an individual clinical sample can harbor rare mutations at minor frequencies. Genetic diversity within an individual clinical sample is oftentimes reflected in rare mutations. Therefore, detecting rare variants prior to treatment may prove to be a useful predictor for therapeutic response. Current rare variant detection algorithms using next generation DNA sequencing are limited by inherent sequencing error rate and platform availability. Findings: Here we describe an optimized implementation of a rare variant detection algorithm called RVD for use in targeted …

Coordinated Dynamic Gene Expression Changes In The Central Nucleus Of The Amygdala During Alcohol Withdrawal., Kate Freeman, Mary M. Staehle, Rajanikanth Vadigepalli, Gregory E Gonye, Babatunde A Ogunnaike, Jan B Hoek, James S Schwaber

Faculty Scholarship for the College of Science & Mathematics

BACKGROUND: Chronic alcohol use causes widespread changes in the cellular biology of the amygdala's central nucleus (CeA), a GABAergic center that integrates autonomic physiology with the emotional aspects of motivation and learning. While alcohol-induced neurochemical changes play a role in dependence and drinking behavior, little is known about the CeA's dynamic changes during withdrawal, a period of emotional and physiologic disturbance.

METHODS: We used a qRT-PCR platform to measure 139 transcripts in 92 rat CeA samples from control (N = 33), chronically alcohol exposed (N = 26), and withdrawn rats (t = 4, 8, 18, 32, and 48 hours; N …

Probe Immobilization Strategies And Device Optimization For Novel Transistor-Based Dna Sensors, Nicholas Michael Fahrenkopf

Legacy Theses & Dissertations (2009 - 2024)

The research presented herein exploits the terminal phosphate group on single stranded DNA molecules for direct immobilization to surfaces utilized in semiconductor device fabrication with the end goal of transistor based DNA sensors. As a demonstration of the feasibility of this immobilization strategy DNA immobilization to a variety of surfaces was evaluated for usefulness in biosensor applications. It was determined that DNA can be directly immobilized to a variety of semiconductor surfaces through the terminal phosphate group. Further, this immobilization allows for the hybridization of the immobilized DNA to complementary target in solution. The immobilization of DNA to hafnium dioxide …

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 …