Engineering Commons^™

Computational Investigation On The Structural Properties Of Neurofilaments And Their Sidearms, Lakshmi Jayanthi

Wayne State University Dissertations

Neurofilaments (NFs) are class IV intermediate filaments, abundantly found in the large myelinated axons. They are the key determinants of axonal diameter and consequently the nerve conduction properties. On the other hand, abnormal NF accumulation has been the hallmark of debilitating neurodegenerative disorders. NF compaction is also one of the pathological manifestations of traumatic axonal Injury. However, the exact relation between the disorganized NFs and the etiology of the neurodegenerative disorders is yet to be fully understood. NFs are assembled from three subunits: Low (NFL), Medium (NFM) and Heavy (NFH). These subunits are characterized by a common alpha helical rod …

Dendrimer Based Nanotherapeutics For Ocular Drug Delivery, Siva Pramodh Kambhampati

Wayne State University Dissertations

PAMAM dendrimers are a class of well-defined, hyperbranched polymeric nanocarriers that are being investigated for ocular drug and gene delivery. Their favorable properties such as small size, multivalency and water solubility can provide significant opportunities for many biologically unstable drugs and allows potentially favorable ocular biodistribution. This work exploits hydroxyl terminated dendrimers (G4-OH) as drug/gene delivery vehicles that can target retinal microglia and pigment epithelium via systemic delivery with improved efficacy at much lower concentrations without any side effects.

Two different drugs Triamcinolone acetonide (TA) and N-Acetyl Cysteine (NAC) conjugated to G4-OH dendrimers showed tailorable sustained release in physiological relevant …

Dtaf Dye Concentrations Commonly Used To Measure Microscale Deformations In Biological Tissues Alter Tissue Mechanics., Spencer E Szczesny, Rachel S. Riley, Dawn M Elliott

Henry M. Rowan College of Engineering Departmental Research

Identification of the deformation mechanisms and specific components underlying the mechanical function of biological tissues requires mechanical testing at multiple levels within the tissue hierarchical structure. Dichlorotriazinylaminofluorescein (DTAF) is a fluorescent dye that is used to visualize microscale deformations of the extracellular matrix in soft collagenous tissues. However, the DTAF concentrations commonly employed in previous multiscale experiments (≥2000 µg/ml) may alter tissue mechanics. The objective of this study was to determine whether DTAF affects tendon fascicle mechanics and if a concentration threshold exists below which any observed effects are negligible. This information is valuable for guiding the continued use of …

Decreased Expression Of Microtubules In Confined Microenvironments Leads To A Reduced Effect Of Paclitaxel On Breast Cancer Cells, Bailey Sayles

Bioengineering Theses - Archive

Despite the current medical options available to patients, cancer cells frequently remain after treatment and metastasize. This is particularly significant because secondary cancers account for 90% of cancer-related fatalities. Using standard lithography techniques to make PDMS-based microchannel devices, different microenvironments for studying metastasizing (MDA-MB-231) and non-metastasizing (MCF-7) breast cancer cells were created. While the cells were in the narrow and wide microchannels, effects of the anti-cancer drug Paclitaxel at different concentrations were examined and compared with the traditional Transwell assay. Paclitaxel stabilizes microtubules inside the cell and restricts replication, making it an ideal drug to target for quickly dividing cancer …

A Glm/Ica Analysis Using Motion Tracking And Electromyography Differentiates Between Brain Activation Due To Intended And Unintended Motions In Fnirs Images Acquired During A Finger Tapping Task Performed By Children With Cerebral Palsy, Nathan Hervey

Bioengineering Theses - Archive

Functional neurological imaging has been shown to be valuable in evaluating brain plasticity in children with cerebral palsy (CP). In recent studies it has been demonstrated that functional near-infrared spectroscopy (fNIRS) is a viable and sensitive method for imaging motor cortex activities in children with CP. However, during unilateral finger tapping tasks children with CP often exhibit mirror motions (unintended motions in the non-tapping hand), and current fNIRS image formation techniques do not account for these motions. Therefore, the resulting fNIRS images contain activation from both intended and unintended motions. In this study, cortical activity was mapped with fNIRS on …

Peripheral Nerve Injuries: Pleiotrophin-Mediated Regeneration Across Long-Gap Injuries And Investigations Into Amputation Neuroma Pain, Benjamin Johnston

Bioengineering Dissertations - Archive

Peripheral nerve injuries can be a chronic clinical challenge for patients. Long recovery periods, functional deficits, and neuropathic pain all complicate healing. Although peripheral nerves are able to regenerate, most gap nerve injuries are repaired by autograft, which induces a secondary injury and provides suboptimal recovery of function. This work provides insights into the use of Pleiotrophin (PTN) to bridge long-gap injures and assess the functional recovery of the common peroneal nerve (CPN) injury model. In addition to regeneration strategies, a painful neuroma-blocking conduit was developed to help patients with amputation neuromas. Lastly, this work addresses the unusual phenomenon of …

Methodological Advances And Application Of Functional Near-Infrared Spectroscopy To Guide Cortical Stimulation For Physical Recovery In Patients With Brain Injury, Bilal Khan

Bioengineering Dissertations - Archive

Non-invasive cortical stimulation used in conjunction with physical therapy can enhance the motor performance of persons with brain injury. Transcranial direct current stimulation (tDCS) is a non-invasive cortical stimulation technique that modulates cortical activation by delivering weak current through a pair of anodal-cathodal (excitation-suppression) electrodes, placed on the scalp over the targeted cortical centers. Recently, application of tDCS over the sensorimotor cortex of stroke patients in conjunction with physical therapy has been shown to induce beneficial plasticity in the injured brain resulting in improved motor performance. However, in all currently reported tDCS-based interventions the locations of electrode pairs used to …

Polymeric Nano/ Microparticles For Management Of Pulmonary Diseases, Jyothi Unnikrishna Menon

Bioengineering Dissertations - Archive

Drug delivery via pulmonary route has emerged as an attractive area of study in the past two decades. This method of administration has multiple advantages for both systemic and local drug delivery due to the availability of a large surface area for drug absorption and higher solute permeability in the lung. Most importantly, inhalational drug delivery provides direct accessibility to the lung via a noninvasive route of administration. Recent literature has shown a surge in the use of nano/micro particles for a wide range of pulmonary applications ranging from targeted and controlled drug delivery to drug screening and tissue regeneration. …

Establishing The Method Of Dual-Tensor For Tract Based Analysis (Dtta) And Investigating Human Brain Developmental Connectome With Diffusion Mri, Virendra Radheshyam Mishra

Bioengineering Dissertations - Archive

Diffusion MRI (dMRI) has the unique ability of studying white matter fiber structure in the human brain in-vivo. The trajectory of the white matter fibers inside the brain can be mapped using the tractography techniques and their structural integrity can be assessed with the help of various metrics such as fractional anisotropy (FA) derived from diffusion tensor imaging (DTI). But with typical dMRI in clinical applications, almost half of human brain white matter (WM) voxels has crossing-fiber regions (CFR) where WM microstructural integrity is significantly underestimated with single tensor FA. A technique adapted to WM tract analysis and correcting the …

Ultrasound-Modulated Fluorescence Techniques, Yuan Liu

Bioengineering Dissertations - Archive

Ultrasound-modulated fluorescence (UMF) imaging has been proposed as a novel imaging modality by combining ultrasound and optical imaging techniques for early cancer detection. In UMF, a focused ultrasound beam is used to modulate the diffused fluorescence photons in the acoustic focal region, and by specifically analyzing the modulated photons, one can isolate and quantify the fluorescence properties within the ultrasonic focal area. Therefore, UMF is able to provide fluorescence contrast while maintaining ultrasound resolution in tissue. The major challenge of UMF is to extract the weakly modulated fluorescence signal from a bright and unmodulated background, i.e. the low modulation efficiency. …

Evaluation And Use Of Regenerative Multi Electrode Interfaces In Peripheral Nerves, Vidhi Desai

Bioengineering Dissertations - Archive

Peripheral nerves offer unique accessibility to the innate motor and sensory pathways that can be interfaced with high degree of selectivity for intuitive and bidirectional control of advanced upper extremity prosthetic limbs. Several peripheral nerve interfaces have been proposed and investigated over the last few decades with significant progress made in the area of sensory feedback. However, clinical translation still remains a formidable challenge due to the lack of long term recordings. Prominent causes include signal degradation, eventual interface failures, and lack of specificity in the low amplitude nerve signals. This dissertation evaluates the capabilities of the newly developed Regenerative …

Development Of Trans-Rectal Ultrasound (Trus) Coupled Diffuse Optical Tomography (Dot) For Prostate Cancer Imaging, Venkaiah Chowdary Kavuri

Bioengineering Dissertations - Archive

Prostate cancer is one of the leading causes among cancer deaths in men in the United States. A minimally invasive real time searching tool for cancer need to be developed, which can enhance the odds of cancer detection; Current diagnostic techniques such as Trans-rectal ultrasound (TRUS) suffers from low sensitivity and specificity. The goal of the dissertation is to develop a Trans-Rectal Ultrasound (TRUS) coupled Diffuse Optical Tomography (DOT) probe that can detect and image prostate cancer. To accomplish the task, an optical clip-on probe has been designed that can incorporate the existing ultrasound probe and can pass through the …

Biliary Tract Differentiation Through Use Of Visible To Nir Hyperspectral Reflectance Imaging, Eleanor F. Wehner

Bioengineering Dissertations - Archive

Cholecystectomies are one of the most common surgeries performed in the United States, and most of the complications which arise from these are injuries to the common bile duct (CBD) resulting from a misidentification of anatomy. Reflectance hyperspectral imaging (HSI) offers a low-cost, non-invasive tool to record superficial chemical spectra of a field of view in many surgical applications. A NIR DLP HSI system is assembled and characterized, and used to gather preliminary CBD reflectance HSI data cubes. NIR hyperspectral imaging (760 nm to 1600 nm) with the DLP HSI system proves ineffectual, so CBD reflectance hyperspectral data collection progresses …

Mri Assessment Of Brain Vascular Reactivity To Physiological Challenges, Binu Panjikattil Thomas

Bioengineering Dissertations - Archive

With a growing need for specific biomarkers in vascular diseases, the past decade has seen a surging interest in mapping brain vascular reactivity. There is great potential that this CVR mapping can be added to standard clinical MRI protocol, but before this is achieved, we need to better understand the mechanism of BOLD signal change to physiological challenges. A signal increase in the BOLD image is usually seen to CO₂ inhalation, but there are reports of negative CVR as well, i.e. decrease in BOLD signal during inhalation of CO₂ gas. Negative CVR is usually seen in patients with vascular occlusions, …

Computational Modeling Of Drug Release From Nerve Guide Conduit Of Different Designs, Lokesh Shamkant Patil

Bioengineering Theses - Archive

Currently there are limited effective strategies and surgical methods for repairing gap peripheral nerve injuries. Autografts are commonly used but with major limitation in the availability of donor graft material and the painful sensations at donor site. These limitations call for the development of new, effective methods for repairing peripheral nerve injuries. The use of nerve guide conduits to facilitate nerve growth and repair have shown promising potential with minimum side-effects but still with limited success in a full functional recovery. The likely clinical outcome could benefit significantly with the use of engineering methodologies in the design, fabrication, surgical delivery …

Cross Wavelet Analysis Of Cerebral Hemodynamics In Young And Older Adults, Mrunmayee Sunil Gandhi

Bioengineering Theses - Archive

Measurement of cerebral autoregulation is important for the evaluation of a number of clinical disorders that affect cerebral blood flow. Cerebral autoregulation is a mechanism that involves dilation and constriction in arterioles to maintain relatively stable cerebral blood flow in response to changes of systemic blood pressure. Traditional assessments of autoregulation focus on the changes of cerebral blood flow velocity in response to large blood pressure fluctuations induced by interventions. This approach is not feasible for patients with impaired autoregulation or cardiovascular regulation. Therefore in this thesis, a non-stationary time-frequency analysis method, Cross Wavelet Transform is used, which assess autoregulation …

Simulation Feasibility Studies Of A High Density Fnirs Imaging System, Pallavi Natekar

Bioengineering Theses - Archive

Functional near infrared spectroscopy (fNIRS) is a technique that enables monitoring brain function, by detecting changes in near-infrared light absorbance resulting from changes in brain hemodynamics during periods of rest and activation. Although the technique has some advantages over other conventional functional imaging methods with its inherently high temporal sampling and detection sensitivity, the sparse spatial sampling of current fNIRS systems limits spatial resolution and requires help from Magnetic Resonance Imaging (MRI) to attain spatial co-registration with anatomical structures. In this work we have performed simulations to test the feasibility of using a high density spatial sampling system as a …

Quantized Nonnegative Matrix Factorization, Ruairí De Fréin

Conference papers

Even though Nonnegative Matrix Factorization (NMF) in its original form performs rank reduction and signal compaction implicitly, it does not explicitly consider storage or transmission constraints. We propose a Frobenius-norm Quantized Nonnegative Matrix Factorization algorithm that is 1) almost as precise as traditional NMF for decomposition ranks of interest (with in 1-4dB), 2) admits to practical encoding techniques by learning a factorization which is simpler than NMF’s (by a factor of 20-70) and 3) exhibits a complexity which is comparable with state-of-the-art NMF methods. These properties are achieved by considering the quantization residual via an outer quantization optimization step, in …

A Bottom-Up Assembly Of Vascularized Bioartificial Constructs Using Ecm Based Microscale Modules, Ramkumar Tiruvannamalai Annamalai

Wayne State University Dissertations

Tissue engineering aims to create functional biological tissues to treat diseases and damaged organs. A primary goal is to fabricate a 3D construct that can promote cell-cell interaction, extra cellular matrix (ECM) deposition and tissue level organization. Accomplishing these prerequisites with the currently available conventional scaffolds and fabrication techniques still remains a challenge. To reproduce the full functionality there is a need to engineer tissue constructs that mimic the innate architecture and complexity of natural tissues. The limited ability to vascularize and perfuse thick, cell-laden tissue constructs has hindered efforts to engineer complex tissues and organs, including liver, heart and …

A Method To Assess Adherence In Inhaler Use Through Analysis Of Acoustic Recordings Of Inhaler Events, Shona D’Arcy, Elaine Machale, Jansen Seheult, Martin S. Holmes, Cian Hughes, Imran Sulaiman, Deirdre Hyland, Conor O’Reilly, Senan Glynn, Thekra Al-Zaabi, John Mccourt, Terence Taylor, Frank Keane, Isabelle Killane, Richard B. Reilly, Richard W. Costello

Articles

Rationale: Poor adherence to inhaler use can be due to poor temporal and/or technique adherence. Up until now there has been no way of reliably tracking both these factors in everyday inhaler use. Objectives: This paper introduces a device developed to create time stamped acoustic recordings of an individual’s inhaler use, in which empirical evidence of temporal and technique adherence in inhaler use can be monitored over time. The correlation between clinical outcomes and adherence, as determined by this device, was compared for temporal adherence alone and combined temporal and technique adherence. Findings: The technology was validated by showing that …

Investigation Of Cardiac Electrophysiology In Human Ventricular Tissue, Kathleen Brownson

Theses and Dissertations--Biomedical Engineering

Individuals with cardiomyopathy are at higher risk to die from sudden cardiac arrest than those with non-failing (NF) hearts. This study examined the differences in electrical properties of failing and NF human hearts in terms of cardiac memory through explicit control of diastolic intervals in a sinusoidal fashion, restitution of action potential duration (APD) through standard and dynamic pacing protocols, maximum rate of depolarization and APD alternans. Recordings of transmembrane potentials were made in tissues extracted from patients with heart failure and one donor NF heart. Computational simulations were performed using the O’Hara Rudy model for generating surrogates of control …

Prefrontal Responses To Digit Span Memory Phases In Patients With Post-Traumatic Stress Disorder (Ptsd): A Functional Near Infrared Spectroscopy Study, Fenghua Tian, Amarnath Yennu, Alexa Smith-Osborne, F. Gonzalez-Lima, Carol S. North, Hanli Liu

Bioengineering Faculty Publications - Archive

Neuroimaging studies of post-traumatic stress disorder (PTSD)-related memory impairments have consistently implicated abnormal activities in the frontal and parietal lobes. However, most studies have used block designs and could not dissociate the multiple phases of working memory. In this study, the involvement of the prefrontal cortex in working memory phases was assessed among veterans with PTSD and age-/ gender-matched healthy controls. Multichannel functional near infrared spectroscopy (fNIRS) was utilized to measure prefrontal cortex hemodynamic activations during memory of neutral (i.e., not trauma-related) forward and backward digit span tasks. An event-related experimental design was utilized to dissociate the different phases (i.e., …

The Effects Of Body Armor On Lower Back And Knee Biomechanics During Basic And Military Inspired Tasks, Megan P. Phillips

Theses and Dissertations--Biomedical Engineering

With increased military personal protection equipment, body armor, comes the addition of carried load. Such person protection in recent history has been instrumental in combating the imminent threats (e.g., improvised explosive devices) of hostile environments, preventing otherwise lethal injuries. However, body armor has been suggested to degrade warfighters’ performance and compound the risk of musculoskeletal injuries. Both performance and risk of injury are intensely related to joint biomechanics. Therefore the objective of this project was set to determine the immediate and prolonged effects of wearing body armor on biomechanics of the lower back and knee. A randomized cross-over study design, …

Interpolation-Based Super-Resolution Reconstruction: Effects Of Slice Thickness, Amir Pasha Mahmoudzadeh, Nasser H. Kashou

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Standard clinical magnetic resonance imaging (MRI) is acquired in two-dimensions where the in-plane resolution is higher than the slice select direction. These acquisitions include axial, coronal, and sagittal planes. To date, there have been few attempts to combine the information of these three orthogonal orientations. This paper aims to take advantage of the different in-plane resolution acquired from each plane orientation and combine them into one volume in order to attain a higher resolution image. This combination of MRI data will allow the detection of smaller areas that would otherwise be missed using only one slice orientation. A comparison of …

Biom 4110/6110: The Science Of Medicine (Syllabus), Bradford D. Pendley

Biomedical Engineering Syllabi Archive

Course Description: Integration of fundamental principles from physics, chemistry, biology and mathematics, and applications of these principles to solve problems in medicine.

Investigating The Effect Of Sio2-Tio2-Cao-Na 2o-Zno Bioactive Glass Doped Hydroxyapatite: Characterisation And Structural Evaluation, Chokchai Yatongchai, Anthony W. Wren, Declan J. Curran, Stuart Hampshire, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effects of increasing bioactive glass additions,

SiO₂-TiO₂-CaO-Na₂O-ZnO up to 25 wt% in increments of 5 wt%, on the physical and mechanical properties of hydroxyapatite (HA) sintered at 900, 1000, 1100 and 1200°C for 2 h was investigated. Increasing both the glass content and the temperature resulted in increased HA decomposition. This resulted in the formation of a number of bioactive phases. However the presence of the liquidus glass phase did not result in increased densification levels. At 1000 and 1100°C the additions of 5 wt% glass resulted in a decrease in density which …

Degradable Borate Glass Polyalkenoate Cements, L. Shen, A. Coughlan, Mark R. Towler, M. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) containing aluminum-free borate glasses having the general composition Ag₂O-Na₂O-CaO-SrO-ZnO- TiO₂-B₂O₃ were evaluated in this work. An initial screening study of sixteen compositions was used to identify regions of glass formation and cement compositions with promising rheological properties. The results of the screening study were used to develop four model borate glass compositions for further study. A second round of rheological experiments was used to identify a preferred GPC formulation for each model glass composition. The model borate glasses containing higher levels of TiO₂ (7.5 mol %) …

A Protocol For Rheological Characterization Of Hydrogels For Tissue Engineering Strategies, Jonathan M. Zuidema, Christopher J. Rivet, Ryan J. Gilbert, Faith A. Morrison

Chemical and Biochemical Engineering Faculty Research & Creative Works

Hydrogels are studied extensively for many tissue engineering applications, and their mechanical properties influence both cellular and tissue compatibility. However, it is difficult to compare the mechanical properties of hydrogels between studies due to a lack of continuity between rheological protocols. This study outlines a straightforward protocol to accurately determine hydrogel equilibrium modulus and gelation time using a series of rheological tests. These protocols are applied to several hydrogel systems used within tissue engineering applications: agarose, collagen, fibrin, Matrigel™, and methylcellulose. The protocol is outlined in four steps: (1) Time sweeps to determine the gelation time of the hydrogel. (2) …

Effect Of Magnetic Nanoparticle Heating On Cortical Neuron Viability, Christopher J. Rivet, Yuan Yuan, Ryan J. Gilbert, Diana Andra Borca-Tasciuc

Chemical and Biochemical Engineering Faculty Research & Creative Works

Purpose: Superparamagnetic iron oxide nanoparticles are currently approved for use as an adjunctive treatment to glioblastoma multiforme radiotherapy. Radio frequency stimulation of the nanoparticles generates localized hyperthermia, which sensitizes the tumor to the effects of radiotherapy. Clinical trials reported thus far are promising, with an increase in patient survival rate; however, what are left unaddressed are the implications of this technology on the surrounding healthy tissue. Methods and materials: Amino silane-coated iron oxide nanoparticles suspended in culture medium were applied to chick embryonic cortical neuron cultures. Cultures were heated to 37 °C or 45 °C by an induction coil system …

Dielectric Characterization Of Coastal Cartilage Chondrocytes, Michael W. Stacey, Ahmet C. Sabuncu, Ali Beskok

Bioelectrics Publications

BACKGROUND: Chondrocytes respond to biomechanical and bioelectrochemical stimuli by secreting appropriate extracellular matrix proteins that enable the tissue to withstand the large forces it experiences. Although biomechanical aspects of cartilage are well described, little is known of the bioelectrochemical responses. The focus of this study is to identify bioelectrical characteristics of human costal cartilage cells using dielectric spectroscopy.

METHODS: Dielectric spectroscopy allows non-invasive probing of biological cells. An in house computer program is developed to extract dielectric properties of human costal cartilage cells from raw cell suspension impedance data measured by a microfluidic device. The dielectric properties of chondrocytes are …