Biomedical Engineering and Bioengineering Commons^™

A Rapid Co-Culture Stamping Device For Studying Intercellular Communication, Amin Hassanzadeh-Barforoushi, Jonathan Shemesh, Nona Farbehi, Mohsen Asadnia, Guan H. Yeoh, Richard P. Harvey, Robert E. Nordon, Majid E. Warkiani

Research outputs 2014 to 2021

Regulation of tissue development and repair depends on communication between neighbouring cells. Recent advances in cell micro-contact printing and microfluidics have facilitated the in-vitro study of homotypic and heterotypic cell-cell interaction. Nonetheless, these techniques are still complicated to perform and as a result, are seldom used by biologists. We report here development of a temporarily sealed microfluidic stamping device which utilizes a novel valve design for patterning two adherent cell lines with well-defined interlacing configurations to study cell-cell interactions. We demonstrate post-stamping cell viability of > 95%, the stamping of multiple adherent cell types, and the ability to control the seeded …

Finite Element And Probabilistic Analysis Of Soft Tissue Structures Of The Human Lumbar Spine, Dana Joseph Coombs

Electronic Theses and Dissertations

Human lumbar spine mechanics are influenced by soft tissue structures. Understanding and properly modeling these structures can help determine pathology, treatment, and implant design and performance. Finite element models of the L4-L5 level of the lumbar spine are often used, which include a representation of the intervertebral disc and spinal ligaments. Validation of these models are typically based on torque rotation data from a single subject or the models use average properties reported in literature. However, experimental testing reports variation up to 40% in ligament stiffness and even greater variability for annulus fibrosis properties. Probabilistic approaches enable consideration of the …

Fluorescent Nanocomposite Of Embedded Ceria Nanoparticles In Crosslinked Pva Electrospun Nanofibers, Nader Shehata, Soha Gaballah, Effat Samir, Aya Hamed, Marwa Saad

Biology Faculty Publications

This paper introduces a new fluorescent nanocomposite of electrospun biodegradable nanofibers embedded with optical nanoparticles. In detail, this work introduces the fluorescence properties of PVA nanofibers generated by the electrospinning technique with embedded cerium oxide (ceria) nanoparticles. Under near-ultra violet excitation, the synthesized nanocomposite generates a visible fluorescent emission at 520 nm, varying its intensity peak according to the concentration of in situ embedded ceria nanoparticles. This is due to the fact that the embedded ceria nanoparticles have optical tri-valiant cerium ions, associated with formed oxygen vacancies, with a direct allowed bandgap around 3.5 eV. In addition, the impact of …

Oxygen Mass Transport In Stented Coronary Arteries, Eoin Murphy, Adrian S. Dunne, David Martin, Fergal Boyle

Articles

Oxygen deficiency, known as hypoxia, in arterial walls has been linked to increased intimal hyperplasia, which is the main adverse biological process causing in-stent restenosis. Stent implantation has significant effects on the oxygen transport into the arterial wall. Elucidating these effects is critical to optimizing future stent designs. In this study the most advanced oxygen transport model developed to date was assessed in two test cases and used to compare three coronary stent designs. Additionally, the predicted results from four simplified blood oxygen transport models are compared in the two test cases. The advanced model showed good agreement with experimental …

A Mechanical Approach To The Characterization Of Material Failure Of Atherosclerotic Lesions, Lindsey A. Davis

Theses and Dissertations

Failure of atherosclerotic plaques can lead to potentially life threatening clinical events such as myocardial infarction (MI), stroke, or transient ischemic attack (TIA). The most frequently described plaque failure mechanism is tensile rupture of the fibrous cap; however, often during angioplasty another plaque failure mechanism occurs in which the atherosclerotic plaque separates from the internal elastic lamina (IEL). This study aims assess the material strength of atherosclerotic lesions using mechanical concepts.

To assess likelihood of plaque dissection at the vessel wall, adhesion strength was assessed in both mouse and human specimens using plaque delamination experiments. Measuring plaque adhesion in transgenic …

A Theoretical Study Of Polymer Based Drug Delivery Systems, Ebtisam Abdullatif Aldaais

Theses and Dissertations

Polymer nanostructured materials for drug delivery applications have witnessed tremendous progress in recent years due to their vast potential. One-end-grafted polymers can form grafted micelles with specific mechanical properties. Biological conditions can alter these properties resulting in the protection or release of drugs. Charged surfactants can also form micelles in an aqueous solution, which can also be manipulated through special conditions. On the micellar surface, self-organized polyelectrolytes can be stimulated to extend their attached ligands and thus increase the probability of binding to targeted receptors. This thesis focuses on modeling polymer-based drug delivery systems by studying the physical interactions between …

Finite Element Modeling And Analysis Applications In Osteogenesis Imperfecta, Jessica M. Fritz, Nicole M. Grosland, Peter Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Understanding the biomechanics of bones in persons with osteogenesis imperfecta (OI) is a key component to further understanding the disease, optimizing treatment and quality of life, as well as injury prevention. However, it is not feasible to study bone biomechanics in vivo. Thus, modeling may play a key role in understanding how OI bones respond to the loading experienced during various activities, especially ambulation. Biomechanical modeling can provide insight into bone fracture risks, such as type and location, from single applied loads or repetitive loading. One method for obtaining this information is via a finite element analysis (FEA). FEA is …

Upper Extremity Inverse Dynamics Model For Loftstrand Crutch-Assisted Gait In Children With Osteogenesis Imperfecta, Brooke A. Slavens, Neha Bhagchandani, Mei Wang, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Role Of Micro-Ct In The Visualization, Measurement, And Quantification Of Bone Structure In Osteogenesis Imperfecta, Robert C. Molthen, John Jameson, Carolyne Albert, Peter Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Assessing The Spatial Relationship Between Fixation And Foveal Specializations, Melissa A. Wilk, Adam M. Dubis, Robert F. Cooper, Phyllis Summerfelt, Alfredo Dubra, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Increased cone photoreceptor density, an avascular zone (FAZ), and the displacement of inner retinal neurons to form a pit are distinct features of the human fovea. As the fovea provides the majority of our vision, appreciating how these anatomical specializations are related is important for understanding foveal development, normal visual function, and retinal disease. Here we evaluated the relationship between these specializations and their location relative to the preferred retinal locus of fixation (PRL). We measured foveal pit volume, FAZ area, peak cone density, and location of the PRL in 22 subjects with normal vision using optical coherence tomography and …

Electrophysiology Of Basal Ganglia (Bg) Circuitry And Dystonia As A Model Of Motor Control Dysfunction, Deepak Kumbhare

Theses and Dissertations

The basal ganglia (BG) is a complex set of heavily interconnected nuclei located in the central part of the brain that receives inputs from the several areas of the cortex and projects via the thalamus back to the prefrontal and motor cortical areas. Despite playing a significant part in multiple brain functions, the physiology of the BG and associated disorders like dystonia remain poorly understood. Dystonia is a devastating condition characterized by ineffective, twisting movements, prolonged co-contractions and contorted postures. Evidences suggest that it occurs due to abnormal discharge patterning in BG-thalamocortocal (BGTC) circuitry. The central purpose of this study …

Characterization Of Fibrin Matrix Incorporated Electrospun Polycaprolactone Scaffold, Cho Yi Wong

Theses and Dissertations

Specific objective: Guided tissue regeneration (GTR) aims to regenerate the lost attachment apparatus caused by periodontal disease through the use of a barrier membrane. For the GTR procedures to be successful, barrier membranes are required to be present at the surgical site for an extended period of time (weeks to months). Synthetic membranes have the advantage of prolonged presence in a wound site; however, they do not actively contribute to wound healing. Biologic membranes are recognized by the host tissue and participate in wound healing but have the disadvantage of early resorption. Therefore, the goal of this study is …

In Vitro Visualization Of Pediatric Sized Mechanical Heart Valve Performance Using Aortic Root Model In Mock Circulatory Loop, Sarah Lederer

Theses and Dissertations

Congenital heart valve disease is one of the most common abnormalities in children, with common valve defects being aortic stenosis, mitral stenosis, and valvular regurgitation. Although adult sized mechanical heart valve (MHV) replacements are widely studied and utilized, there are currently no FDA approved prosthetic heart valves available for the pediatric population. This is due to a variety of reasons such as a limited patient pool for clinical trials, limited valve sizes, and complex health histories in children. Much like adult sized mechanical heart valves, potential complications with pediatric heart valve replacements include thrombosis, blood damage due to high shear …

Novel Small Airway Model Using Electrospun Decellularized Lung Extracellular Matrix, Bethany M. Young

Theses and Dissertations

Chronic respiratory diseases affects many people worldwide with little known about the mechanisms diving the pathology, making it difficult to find a cure. Improving the understanding of smooth muscle and extracellular matrix (ECM) interaction is key to developing a remedy to this leading cause of death. With currently no relevant or controllable in vivo or in vitro model to investigate diseased and normal interactions of small airway components, the development of a physiologically relevant in vitro model with comparable cell attachment, signaling, and organization is necessary to develop new treatments for airway disease. The goal of this study is to …

Improved Capability Of A Computational Foot/Ankle Model Using Artificial Neural Networks, Ruchi D. Chande

Theses and Dissertations

Computational joint models provide insight into the biomechanical function of human joints. Through both deformable and rigid body modeling, the structure-function relationship governing joint behavior is better understood, and subsequently, knowledge regarding normal, diseased, and/or injured function is garnered. Given the utility of these computational models, it is imperative to supply them with appropriate inputs such that model function is representative of true joint function. In these models, Magnetic Resonance Imaging (MRI) or Computerized Tomography (CT) scans and literature inform the bony anatomy and mechanical properties of muscle and ligamentous tissues, respectively. In the case of the latter, literature reports …

Characterization Of Poly(Dimethylsiloxane) Blends And Fabrication Of Soft Micropillar Arrays For Force Detection, Thomas J. Petet Jr

Theses and Dissertations

Diseases involving fibrosis cause tens of thousands of deaths per year in the US alone. These diseases are characterized by a large amount of extracellular matrix, causing stiff abnormal tissues that may not function correctly. To take steps towards curing these diseases, a fundamental understanding of how cells interact with their substrate and how mechanical forces alter signaling pathways is vital. Studying the mechanobiology of cells and the interaction between a cell and its extracellular matrix can help explain the mechanisms behind stem cell differentiation, cell migration, and metastasis. Due to the correlation between force, extracellular matrix assembly, and substrate …

An Investigation Of Kinetic Visual Biofeedback On Dynamic Stance Symmetry, Trisha J. Massenzo

Theses and Dissertations

The intent of the following research is to utilize task-specific, constraint-induced therapies and apply towards dynamic training for symmetrical balance. Modifications to an elliptical trainer were made to both measure weight distributions during dynamic stance as well as provide kinetic biofeedback through a man-machine interface. Following a review of the background, which includes research from several decades that are seminal to current studies, a design review is discussed to cover the design of the modified elliptical (Chapter 2).

An initial study was conducted in a healthy sample population in order to determine the best visual biofeedback representation by comparing different …

Influence Of Nb On The Β → Α″ Martensitic Phase Transformation And Properties Of The Newly Designed Ti-Fe-Nb Alloys, Shima Ehtemam-Haghighi, Yujing Liu, Guanghui Cao, Lai-Chang Zhang

Research outputs 2014 to 2021

A series of Ti-7Fe-xNb (x = 0, 1, 4, 6, 9, 11 wt.%) alloys was designed and cast to investigate the β → α″ martensitic phase transformation, β phase stability, the resulting microstructure and mechanical properties. Phase analysis revealed that only Ti-7Fe-11Nb alloy shows a single body-centred cubic β phase microstructure while the others are comprised of β and orthorhombic α″ phases. Moreover, Nb addition up to 11 wt.% enhances the stability and volume fraction of β phase in the microstructure, hence reducing the propensity of the alloy system to form α″ phase during quenching. Compressive yield strength and hardness …

A Review Of Current Neuromorphic Approaches For Vision, Auditory, And Olfactory Sensors, Anup Vanarse, Adam Osseiran, Alexander Rassau

Research outputs 2014 to 2021

Conventional vision, auditory, and olfactory sensors generate large volumes of redundant data and as a result tend to consume excessive power. To address these shortcomings, neuromorphic sensors have been developed. These sensors mimic the neuro-biological architecture of sensory organs using aVLSI (analog Very Large Scale Integration) and generate asynchronous spiking output that represents sensing information in ways that are similar to neural signals. This allows for much lower power consumption due to an ability to extract useful sensory information from sparse captured data. The foundation for research in neuromorphic sensors was laid more than two decades ago, but recent developments …

An Algorithm For Extracting The Ppg Baseline Drift In Real-Time, Tuan Ngoc Nguyen

Theses: Doctorates and Masters

Photoplethysmography is an optical technique for measuring the perfusion of blood in skin and tissue arterial vessels. Due to its simplicity, accessibility and abundance of information on an individual’s cardiovascular system, it has been a pervasive topic of research within recent years. With these benefits however there are many challenges concerning the processing and conditioning of the signal in order to allow information to be extracted. One such challenge is removing the baseline drift of the signal, which is caused by respiratory rate, muscle tremor and physiological changes within the body as a response to various stimuli.

Over the years …