Biomedical Engineering and Bioengineering Commons^™

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 …

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 …

Role Of E-Cadherin Force In The Spatial Regulation Of Cell Proliferation, Abhinav Mohan

Theses and Dissertations

Cell proliferation and contact inhibition play a major role in maintaining epithelial cell homeostasis. A hallmark of epithelial cells is strong cell-cell junctions. These junctions include E-Cadherin, a type of adherens junction that is critical for both barrier function and contact inhibition. Prior experiments by other groups have shown that adherens junctions are subject to mechanical tension. Externally applied forces (e.g. stretch) results in changes in E-Cadherin forces that coordinate proliferation. My current work tests the hypothesis that E-Cadherin forces mediate the spatial regulation of cell proliferation even in the absence of externally applied forces.

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 …

A Computational Study Of Curvature In The Outflow Graft Of A Continuous Flow Left Ventricular Assist Device, Laura Patterson

Theses and Dissertations

Left ventricular assist devices (LVADs) are an increasingly utilized therapy for end-stage heart failure. Thrombosis within the graft from the pump to the aorta has been documented, but is poorly researched. This study examines the effect of graft geometry, as measured by radius of curvature, bend angle, and diameter, on thrombogenic flow patterns within the graft for a range of flow conditions. It also examines the effect blood properties, including viscosity and density, on these flow patterns. The results indicated that radius of curvature had a powerful effect on thrombogenic flow patterns. Flowrate and bend angle were also influential. The …

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 …

A Device For The Objective Assessment Of Adhd Using Eye Movements, Ankita Dosaj, Jefferson Overlin, Cassie Turnage

Capstone Design Expo Posters

Attention deficit hyperactivity disorder (ADHD) is a commonly diagnosed psychiatric disorder characterized by lack of focus, self-control,and hyperactivity. ADHD is difficult to diagnose without extensive observation by an expert, and even then is often misdiagnosed. Current methods of pediatric diagnosis rely on subjective measures of activity and behavior relative to other children [3]. Proper diagnosis is critical in preventing unnecessary prescription of the powerful, habit-forming nature of the drugs used to manage ADHD, such as Adderall and Ritalin [1][5]. Research has shown that patients with ADHD show abnormalities in reading tests and antisaccade tests, as these tests gauge ability to …

Non-Invasive Blood Glucose Monitoring System, Brittany Martinez, Brittany Noah, David Decker

Capstone Design Expo Posters

The objective of this project is to create a non-invasive hypoglycemic alert system that will detect a drop in blood sugar in type 1 diabetics during sleep. This will be achieved by creating an algorithm that couples heart rate variability with skin conductance to increase the accuracy of hypoglycemia detection. The device will be housed in a torso strap that will include: electrodes located over the user’s rib cage, a skin conductance sensor placed in the user’s armpit, a microcontroller to collect and process the data, and vibrating motors that will awaken the patient if hypoglycemia is detected. Integrating the …

A Non-Contact System For Measuring Wrist And Carpal Kinematics, Shruthi Muralidharan, Kristina Hendel, Joseph Newton, Vivek Patel

Capstone Design Expo Posters

Ligamentous and bone injuries in the wrist affect tens of thousands of adults per year and leads to abnormal function. Surgical procedures as well as physical therapy intended to restorefunction have room for improvement. Measuring wrist kinematics of the small carpal bones is necessary to understand the effect of ligamentous injury during normal motion.Currently there are motion analysis systems that are used to track large scale movementfor total body kinematics such as gait analysis. The accuracy of these systems is catered toward capturing gross movement and cannot precisely measure on the order of millimeters necessary for carpal kinematics. There are …

Flow-Cytometry Machine For The Developing World, Paul Howell, Jewel Nkwocha, Jaynie Laverty

Capstone Design Expo Posters

Flow cytometry provides critical diagnostic, measurement, and research applications across many healthcare and biological disciplines. Its use in the detection of blood-cancers, HIV/AIDS, cell differentiation, and viral detection is unique and unparalleled. Despite flow cytometry’s vast array of applications, its use is limited by expense. Rather than individual labs being able to afford a dedicated machine, core facilities are developed and the research is exported. In addition, flow cytometry’s high costs create a barrier to its implementation in developing nations.

There were 35 million people living with HIV in 2013, nearly 1% of the world’s population. There are more than …

Independent Exercise Assistive Device For Individuals With Visual Impairments, Ashley Duke, Megan Goldberg, Lindsay Schnur

Capstone Design Expo Posters

Physical exercise is challenging for individuals who are blind because they lack the spatial awareness necessary to imitate described motions for exercises, and additionally require physical guidance. The current solutions involve tactile equipment to assist in body placement, but a person with low vision cannot compare their own position to the correct position and adjust properly. The proposed solution is an instructional yoga program that will give feedback to the user based on her exercise performance, allowing people who are blind to be able to perform these exercises independently at home. The design will incorporate the Skeletal Tracking program of …

Effect Of Four Approaches To Oral Feeding Progression On Clinical Outcomes In Preterm Infants, Rita H. Pickler, Barbara A. Reyna, Paul A. Wetzel, Mary Lewis

Biomedical Engineering Publications

Background. The purpose of this study of preterm infants was to test the effect of four approaches to the time of transition from gavage to full oral feedings, time to discharge, and weight gain during the transition.Methods. A randomized experimental design was used with four intervention groups: early start (32 weeks' postmenstrual age)/slow progressing experience (gradually increasing oral feedings offered per day); early start/maximum experience (oral feedings offered at every feeding opportunity); late start (34 weeks' postmenstrual age)/slow progressing experience; and late start/maximum experience. Results. The analysis included 86 preterm infants. Once oral feedings were initiated, …

Regulation Of Osteoblast Differentiation By Acid-Etched And/Or Grit-Blasted Titanium Substrate Topography Is Enhanced By 1,25(Oh)2d3 In A Sex-Dependent Manner, Rene Olivares-Navarrete, Sharon L. Hyzy, Barbara D. Boyan, Zvi Schwartz

Biomedical Engineering Publications

This study assessed contributions of micron-scale topography on clinically relevant titanium (Ti) to differentiation of osteoprogenitor cells and osteoblasts; the interaction of this effect with 1𝛼,25-dihydroxyvitamin D₃ (1𝛼,25(OH)₂D₃); and if the effects are sex-dependent. Male and female rat bone marrow cells (BMCs) were cultured on acid-etched (A, 𝑅_𝑎 = 0.87 𝜇m), grit-blasted (GB, 𝑅_𝑎 = 3.90 𝜇m), or grit-blasted/acid-etched (SLA, 𝑅_𝑎 = 3.22 𝜇m) Ti. BMCs were sensitive to surface topography and underwent osteoblast differentiation. This was greatest on SLA; acid etching and grit blasting contributed additively. Primary osteoblasts were also sensitive …

Frontal Cryosectioning: An Improved Protocol For Sectioning Large Areas Of Fibrous Scaffolds, Casey Grey, David G. Simpson

Biomedical Engineering Publications

Fibrous tissue engineering scaffolds, such as those produced by electrospinning, cannot achieve their clinical potential until deep cell-scaffold interactions are understood. Even the most advanced imaging techniques are limited to capturing data at depths of 100 µm due to light scatter associated with the fibers that compose these scaffolds. Conventional cross-sectional analysis provides information on relatively small volumes of space and frontal sections are difficult to generate. Current understanding of cellular penetration into fibrous scaffolds is limited predominantly to the scaffold surface. Although some information is available from cross-sections, sections vary in quality, can distort spatial scaffold properties, and offer …

Osteogenic Embryoid Body-Derived Material Induces Bone Formation In Vivo, Ken Sutha, Zvi Schwartz, Yun Wang, Sharon Hyzy, Barbara D. Boyan, Todd C. Mcdevitt

Biomedical Engineering Publications

The progressive loss of endogenous regenerative capacity that accompanies mammalian aging has been attributed at least in part to alterations in the extracellular matrix (ECM) composition of adult tissues. Thus, creation of a more regenerative microenvironment, analogous to embryonic morphogenesis, may be achieved via pluripotent embryonic stem cell (ESC) differentiation and derivation of devitalized materials as an alternative to decellularized adult tissues, such as demineralized bone matrix (DBM). Transplantation of devitalized ESC materials represents a novel approach to promote functional tissue regeneration and reduce the inherent batch-to-batch variability of allograft-derived materials. In this study, the osteoinductivity of embryoid body-derived material …

Patterned Feeding Experience For Preterm Infants: Study Protocol For A Randomized Controlled Trial, Rita H. Pickler, Paul A. Wetzel, Jareen Meinzen-Derr, Heather L. Tubbs-Cooley, Margo Moore

Biomedical Engineering Publications

Background

Neurobehavioral disabilities occur in 5–15 % of preterm infants with an estimated 50–70 % of very low birth weight preterm infants experiencing later dysfunction, including cognitive, behavioral, and social delays that often persist into adulthood. Factors implicated in poor neurobehavioral and developmental outcomes are hospitalization in the neonatal intensive care unit (NICU) and inconsistent caregiving patterns. Although much underlying brain damage occurs in utero or shortly after birth, neuroprotective strategies can stop lesions from progressing, particularly when these strategies are used during the most sensitive periods of neural plasticity occurring months before term age. The purpose of this randomized …

3-D Culture Systemfor Rapid Expansion Of Human Neural Stem Cells, Waleed Ilyas, Jeeyun Park, Dan Reep, Lawrence Talej

Capstone Design Expo Posters

Research into stem cells is a growing field of contemporary biology due to their extraordinary potential to develop into myriad cell types for use in regenerative medicine and research applications. Stem cells can vary from adult stem cells, embryonic stem cells, or induced pluripotent stem cells, or iPS. Due to the high potential for therapeutic applications, or individualized medicine, there is an increasing demand for stem cell quantities since a critical cell count must be met to demonstrate any therapeutic effect. The problem lies in the amount of time it takes to culture this critical cell count. Isolating fibroblasts in …

Toy For Preschoolers With Deaf-Blindness, Allison R. Beckmann, Chelsea B. Gebs, Julia-Grace Polich

Capstone Design Expo Posters

There are approximately 70,000-100,000 people living in America that are diagnosed as deaf-blind. Since children with deaf-blindness are an extreme minority in the US, research, toys and technological advancements for these children get overlooked. As a result, the developmental processes of children with deaf-blindness are delayed by several years, compared to normal children, due to the lack of resources available to encourage learning. According to Virginia’s Department of Education standards of learning for preschoolers, development physically, mathematically,of environmental awareness and of a sense of self are core requirements for Kindergarten. Therefore, there is a need for a toy that will …

Decellularization Of Porcine Lung Tissue, Kirsten Hulbert, Linh Ta, Lumumba Reid, Mahir Dagra, Baltej Dhillon

Capstone Design Expo Posters

Our project aims to standardize the decellularization of a porcine lung by creating a bioreactor to house the lung, automating the decellularization process and developing a protocol that will increase the precision and the repeatability of the process. Our deliverables include a working prototype, an automated system that will inform the user when the decellularization process is complete, a pressure sensor to control perfusion, and automated pressurized pulses that will increase the rate of decellularization.

Our accomplishments thus far include: a design for a working prototype that will decellularize a porcine lung, determining the proper rate to perfuse the lung, …

Device To Deliver Endodontic Material For Temporary Dental Fillings, Garrett N. Cyprus, Hisham Kamoun, Gireesh B. Reddy, Ali Salman

Capstone Design Expo Posters

Root canal therapy requires patients be treated over several visits to clean and shape the pulp chamber. In endodontic treatments, cotton wool is placed beneath the temporary filling to preserve the space of the pulp chamber and to prevent any blockage of the root canals with temporary filling between clinic visits. Despite its simple application and affordability, cotton wool can lead to fibrous remnants in the pulp chamber or become incorporated into the temporary filling, which can lead to micro-leakage or bacterial colonization on the cotton fibers and subsequent infection.

Gelatin capsules or silica gels are proposed endodontic materials which …

Fluorescent Biosensors To Measure Endothelial Cell Responses To Fluid Shear Stress, Natalie Noll

UROP Posters

The response of endothelial cells, innermost layer of blood vessels, to blood flow is thought to be critical in the initiation and progression of atherosclerosis. Atherosclerosis in the human body is non-random and is highly correlated to vessel sites which experience oscillatory and reversing blood flow. Endothelial cells (ECs), the inner most cell layer of blood vessels are highly responsive to the drag force from blood flow, known as shear stress. To study endothelial cell responses to shear stress we used a parallel plate flow chamber in which we exposed endothelial cells to defined fluid shear stress. Using fluorescence resonance …

Ex Vivo Dna Cloning, Adam B. Fisher

Theses and Dissertations

Genetic engineering of microbes has developed rapidly along with our ability to synthesize DNA de novo. Yet, even with decreasing DNA synthesis costs there remains a need for inexpensive, rapid and reliable methods for assembling synthetic DNA into larger constructs or combinatorial libraries. While technological advances have resulted in powerful techniques for in vitro and in vivo assembly of DNA, each suffers inherent disadvantages. Here, an ex vivo DNA cloning suite using crude cellular lysates derived from E. coli is demonstrated to amplify and assemble DNA containing small sequence homologies. Further, the advantages of an ex vivo approach are …

Primary Cilia Mechanotransduction And Microtubule Stability In Mechanically Stretched Lung Adenocarcinoma Cells, Monika Rassi Radhika

Theses and Dissertations

The objective of this study is to investigate the role of microtubule based organelle, the primary cilia in lung adenocarcinoma by i) Quantifying the presence of primary cilia in several Non Small Cell Lung Cancer (NSCLC) cell lines in response to mechanical stimuli, ii) Attempting to determine the role of primary cilia in cell migration, iii) Investigating the effects of Paclitaxel(Taxol) resistance in lung cancer cells, iv) Analyzing the response of lung cancer cells to Smoothened Inhibitors and v) Determining the effects of Transforming Growth Factor Beta-1(TGF-β1) induced Epithelial to Mesenchymal Transition(EMT) in lung cancer cells. To ascertain the effects …

Generation And Delivery Of Charged Aerosols To Infant Airways, Landon T. Holbrook

Theses and Dissertations

The administration of pharmaceutical aerosols to infants on mechanical ventilation needs to be improved by increasing the efficiency of delivery devices and creating better ways of evaluating potential therapies. Aerosolized medicines such as surfactants have been administered to ventilated infants with mixed results, but studies have shown improvement in respiratory function with a much lower dose than with liquid instillation through an endotracheal tube (ETT). An aerosolized medicine must be transported through the ventilation tubing and deposit in the lungs to have the desired therapeutic response.

This work has taken a systematic approach to (i) develop new devices for the …

Evaluation Of A Novel Myoelectric Training Device, Joshua A. Arenas

Theses and Dissertations

Recent technological developments have implemented the use of proportional control in prosthetic hands, giving rise to the importance of appropriate myoelectric control. EMG models in the past have assumed a linear proportionality to simplify the EMG-force relationships. However, it has been shown that a non-linear EMG-force relationship may be a more effective model. This study focused on evaluating three different control algorithms for a novel myoelectric training device, consisting of a toy car controlled by EMG signals from the distal muscles in the arm. Sixteen healthy adult subjects (5 male and 11 female) with an average age of 23.6 years …

The Effects Of Fatigue On Lower Extremity Kinetics And Kinematics In Subjects With Known Ankle Instability, Lindsay E. Clayton

Theses and Dissertations

The goal of this study was to evaluate biomechanical differences between healthy subjects and those with ankle instability during the gradual onset of lower extremity fatigue from a landing activity. An understanding of these differences is needed in order to prevent future injury to or further debilitation in individuals with ankle instability. A functional fatiguing activity was designed to focus fatigue on the quadriceps muscles, as those are the muscles most frequently fatigued during sport. Measures were taken throughout the progression of fatigue with a force plate and a motion tracking system and included vertical ground reaction force and lower …

Peracetic Acid: A Practical Agent For Sterilizing Heat-Labile Polymeric Tissue-Engineering Scaffolds, William R. Trahan

Theses and Dissertations

Advanced biomaterials and sophisticated processing technologies aim to fabricate tissue-engineering scaffolds that can predictably interact within a biological environment at a cellular level. Sterilization of such scaffolds is at the core of patient safety and is an important regulatory issue that needs to be addressed prior to clinical translation. In addition, it is crucial that meticulously engineered micro- and nano- structures are preserved after sterilization. Conventional sterilization methods involving heat, steam and radiation are not compatible with engineered polymeric systems because of scaffold degradation and loss of architecture. Using electrospun scaffolds made from polycaprolactone (PCL), a low melting polymer, and …

Modification And Evaluation Of A Brain Computer Interface System To Detect Motor Intention, Christopher V. Hagerty-Hoff

Theses and Dissertations

It is widely understood that neurons within the brain produce electrical activity, and electroencephalography—a technique used to measure biopotentials with electrodes placed upon the scalp—has been used to observe it. Today, scientists and engineers work to interface these electrical neural signals with computers and machines through the field of Brain-Computer Interfacing (BCI). BCI systems have the potential to greatly improve the quality of life of physically handicapped individuals by replacing or assisting missing or debilitated motor functions. This research thus aims to further improve the efficacy of the BCI based assistive technologies used to aid physically disabled individuals. This study …