Biomedical Engineering and Bioengineering Commons^™

A Psa Process For An Oxygen Concentrator, Aaron A. Moran

ETD Archive

Oxygen is used in a variety of chemical processes and for medical purposes throughout the world. Pressure swing adsorption (PSA) has become a viable alternative to cryogenic distillation for the separation of oxygen from air with the development of advanced adsorbents like zeolites. PSA processes are inherently complex because it is a dynamic process. Efficient operation of a PSA process is necessary in order to utilize the capacity of the adsorbent as much as possible and reduce the power requirements of the process.In this thesis, a novel zeolite adsorbent was utilized in a PSA process for oxygen generation with the …

Benefits Of Nitric Oxide Cues To Matrix Synthesis By Healthy And Aneurysmal Human Smooth Muscle Cells Within 3d Cocultures, Phillip Simmers

ETD Archive

Vascular diseases such as atherosclerosis and aneurysms are characterized by the over-proliferation and migration of aortic smooth muscle cells (SMCs), and degradation of extracellular matrix (ECM) within the vessel wall, leading to compromise in cell-cell and cell-matrix signaling pathways. Recent tissue engineering approaches to regulate SMC over-proliferation and enhance healthy ECM synthesis showed promise, but resulted in low crosslinking efficiency and matrix deposition yields. In this study, the benefits of exogenous nitric oxide cues, delivered from S-Nitrosoglutathione (GSNO), to cell proliferation and matrix deposition by adult human aortic SMCs (HA-SMCs) within 3D biomimetic cultures have been explored. The first experiment …

Effects Of Environmental Heavy Metals On Neural Stem Cell Survival And Differentiation, Sameera S. Clev Tasneem

ETD Archive

No abstract provided.

Development And Application Of Biomimetic Electrospun Nanofibers In Total Joint Replacement, Wei Song

Wayne State University Dissertations

Failure of osseointegration (direct anchorage of an implant by bone formation at the bone-implant surface) and implant infection (such as that caused by Staphylococcus aureus, S. aureus) are the two main causes of implant failure and loosening. There is a critical need for orthopedic implants that promote rapid osseointegration and prevent bacterial colonization, particularly when placed in bone compromised by disease or physiology of the patients. A better understanding of the key factors that influence cell fate decisions at the bone-implant interface is required. Our study is to develop a class of "bone-like" nanofibers (NFs) that promote osseointegration while preventing …

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 …