Engineering Commons^™

A Depolymerization Based Model Of Neuron Growth Cone Shape And Motility, Neerajha Nagarajan

Master's Theses

Cell migration is a ubiquitous process underlying critical biological mechanisms like wound healing, cancer metastasis and even neuron growth cone motility. It is a critical process for the living organisms as it ensures proper functioning of the system, for example, crawling fibroblasts endure closure of wounds during wound healing. Here we focus our interest on neuron growth cones, a sensory and motile organelle present at the tip of extending neurites, like the axons, in neurons. These are responsible for neuron pathfinding onto specific targets and synapses, in responses to various guidance cues. Interestingly, the motility of the growth cones is …

Development Of Simulation Platform For Oropharyngeal Airway Placement And Design Evaluation Of The Bardo Airway, Lewis On Hang Lee

Master's Theses

Off-label use of traditional Oropharyngeal Airway (OPA) as a bite-block, and the subsequential procedure of force exertion of the device by physician has caused many cases of patient’s teeth damage and monetary loss, as the patient’s incisors were damaged while clenching on the OPA during an adverse scenario called “Emergency Clenching”. To remedy this harmful situation, Bardo OPA was developed by Dr. Theodore Burdumy. The Bardo airway has unique design to transfer the clenching force from incisor to the molar. However, the Bardo OPA is one-sized, and cannot fit most of the patients like the commonly-used OPAs, such as the …

Measuring Impedance Of Tissues Using A Microfabricated Microelectrode Array, Ashwini Bhat

Master's Theses

MEASURING IMPEDANCE OF TISSUES USING A MICROFABRICATED MICROELECTRODE ARRAY By Ashwini Bhat

This thesis looks at the possibility of using impedance spectroscopy for differentiating tissue, using a microelectrode array (MEA). The thesis first discusses the background and the motivation for this thesis. It covers the certain basic concepts of the human skin starting from the top epidermis layer all the way to the deep dermis layers of the skin. Then it discusses different types of skin cancer and how they occur, in humans. It also discusses various microfabrication techniques such as oxidation, wet etching, sputtering and photolithography for the creation …

Implementation Of Novel Group Delay Decomposition Method And Surgical Protocol For Assessing Peripheral Neuropathy, Sammy Paul Nicolas

Master's Theses

This paper outlines a surgical procedure for exposing and stimulating the sciatic nerve of an anesthetized rodent for purposes of obtaining conduction velocity readings. The ability to accurately quantify nerve conduction velocity has potential for use in the field of diagnostic medicine and disease characterization. An accurate reading depends on both the surgical method used to expose the desired nerve without imposing onto it any physical trauma as well as the stimulation protocol used to initiate action potentials. This paper contains the specific steps required to set up the necessary hardware and software for electrical stimulation as well as a …

Responding To Dangerous Accidents Among The Elderly: A Fall Detection Device With Zigbee-Based Positioning, Michael R. Putnam

Master's Theses

The following paper describes a fall detection and activity monitoring system with position detection based on Zigbee transceivers.The main objective is to reduce the time taken for emergency personnel to respond to falls among the elderly. Especially when the victim is unconscious or delirious, position tracking reduces location determination time within a busy hospital or nursing home environment and facilitates immediate treatment. Reduced response times correlate to decreased morbidity and mortality rates. Background is provided on the major wireless network advances currently deployed in a healthcare setting for asset and personnel tracking, etiology of falls, and several methods of detecting …

Hydrodynamic Focused Passive Separation Under Continuous Flow In A Microfluidic Chip, Jad Kanbar

Master's Theses

A continuous flow, passive separation device was designed using an equivalent circuit to create variable flow rates for hydrodynamic focusing to drain channels and collection outlets. By varying the diameter of the sample inlet connection into the reservoir, the particle position was influenced significantly, which enabled desired separations. Additionally it was noted that the relative, horizontal position of the inlet also had a significant influence on particle position within the device. A dimensionless number, the Characteristic Sample Inlet, was developed to relate geometric properties of the inlet reservoir to downstream particle distribution. It was found that a 2:1 ratio between …

Tissue Engineering A Blood Vessel Mimic While Monitoring Contamination Through Sterility Assurance Testing, Navid Djassemi

Master's Theses

Tissue Engineering A Blood Vessel Mimic While Monitoring Contamination Through Sterility Assurance Testing

Navid Djassemi

Tissue engineering blood vessel mimics has been proposed as a method to analyze the endothelial cell response to intravascular devices that are used in today’s clinical settings for the treatment of cardiovascular disease. Thus, the development of in vitro blood vessel mimics (BVMs) in Cal Poly’s Tissue Engineering Lab has introduced the possibility of assessing the characteristics of cellular response to past, present, and future intravascular devices that aim at treating coronary artery disease.

This thesis aimed at improving the methods and procedures utilized in …

Development And Characterization Of An In-House Custom Bioreactor For The Cultivation Of A Tissue Engineered Blood-Brain Barrier, Amin Hadi Mirzaaghaeian

Master's Theses

The development of treatments for neurological disorders such as Alzheimer’s and Parkinson’s disease begins by understanding what these diseases affect and the consequences of further manifestation. One particular region where these diseases can produce substantial problems is the blood-brain barrier (BBB). The BBB is the selective diffusion barrier between the circulating blood and the brain. The barrier’s main function is to maintain CNS homeostasis and protect the brain from the extracellular environment. The progression of BBB research has advanced to the point where many have modeled the BBB in vitro with aims of further characterizing and testing the barrier. Particularly, …

Development Of In Vitro Tissue Engineered Blood Vessel Mimics In Complex Geometries For Coronary Stent Testing, Robert Dalton Chavez

Master's Theses

Coronary heart disease is the leading cause of death in the United States and occurs when plaque occludes coronary arteries. Coronary stents, which may be used to treat coronary occlusions, are small metal tubes that are implanted in coronary arteries to restore blood flow. After stent implantation, endothelial cells grow over the stent so that blood contacts the endothelial cells instead of the stent surface; this event is known as re-endothelialization. Re-endothelialization prevents blood from clotting on the stent surface and is a good predictor of stent success. Blood vessel mimics (BVMs) are in vitro tissue engineered models of human …

Characterization Of Tight Junction Formation In An In-Vitro Model Of The Blood-Brain Barrier, Michael Robert Machado

Master's Theses

Active and passive transport of substances between the microcirculation in the brain and the central nervous system is regulated by the Blood-Brain Barrier (BBB). This barrier allows for chronic and acute modulation of the CNS microenvironment, and protects the brain from potentially noxious compounds carried in the circulatory system. In-vitro modeling of the BBB has become the target of much research over the past decade, as there are many unanswered questions regarding modulations in the permeability of this barrier. Additionally, the development of a practical and inexpensive model of the BBB would facilitate a much more efficient drug development process. …

Enhanced Hydrocarbon Biodegradation Using Bioaugmentation With Biowish™-Aqua Fog, Michael Robert Lehrer

Master's Theses

This study was done to determine the effectiveness of a commercially available bioaugmentation product, BiOWiSH^TM-Aqua FOG, for remediating petroleum-contaminated sandy soil. Biodegradation enhancement by BiOWiSH^TM-Aqua FOG was evaluated in laboratory microcosms by directly measuring total petroleum hydrocarbon (TPH) and indirectly using respirometry. Attempts were made to enrich hydrocarbon-degrading bacteria in BiOWiSH^TM-Aqua FOG, and the resulting enrichment cultures were screened using respirometry as well. Potential hydrocarbon-degrading bacteria in BiOWiSH^TM-Aqua FOG were isolated. Experiments were performed at bench-scale using microcosm bottles containing sand contaminated with either motor oil or No. 2 diesel fuel. The …

A New Computational Model To Augment The Design Of Microfluidic Separations: Electric Field Assisted, Hydrodynamic Chromatography, Jeffrey D. Wells

Master's Theses

This project encompasses the implementation of a computational model to simulate the microfluidic separation of like-charged particles in a continuous flow environment. By accomplishing this task the model can be used to optimize future fractionations by tailoring the process parameters to the properties of the target particles. The primary goal of this project is to develop a vectorized code within Matlab® that captures a sufficient quantity of the physics in separations to assist with the optimization and design of microfluidic systems.

This project differs from other computational models in that it utilizes a personal computer to run the simulation in …

Development And Characterization Of Phospholipid Encapsulated Quantum Dot Constructs For Biologic Applications, Laura C. Sparks

Master's Theses

DEVELOPMENT AND CHARACTERIZATION OF PHOSPHOLIPID ENCAPSULATED QUANTUM DOT CONSTRUCTS FOR BIOLOGIC APPLICATIONS

The American Cancer Society predicts that 577,190 cancer-related deaths and 1,638,910 newly diagnosed cases of cancer will occur in 2012. As these statistics show, cancer is a prevalent and devastating health issue; determined by the Mayo Clinic to be the second leading cause of death in the United States. Skin cancer is the most common form of cancer in the United States. In 2012 more than 68,000 Americans will be diagnosed with melanoma, 48,000 will be diagnosed with an early form of the disease that has not yet …

Effects Of Ovariectomy, Seasonal Changes, And Anatomical Position On The Compact Bone Remodeling As Seen In The Adult Ovine Model, Erica Wong

Master's Theses

The purpose of this study is to characterize the compact bone remodeling of the ovariectomized ewe and its effectiveness as an animal model for studies of postmenopausal osteoporosis. The use of animal models is a beneficial way to evaluate the effectiveness of medical devices and therapeutic agents for treating diseases. The ovine model is an attractive option because of its large size and similar bone remodeling to humans. However, this species, like most animals, does not undergo a natural menopause, making an ovariectomy necessary for studies of estrogen depletion. The OVX (ovariectomized) sheep has been widely accepted as a model …

Comparing Anti-Vegf Antibodies And Aptamers On Paper Microfluidic-Based Platforms, Katherine Noel Clayton

Master's Theses

The field of microfluidics is expanding into what is known as paper microfluidics. This uses a paper platform rather than materials (i.e. PDMS, PMMA) that are commonly used in microfluidics research. Current devices require an expensive manufacturing process and external sources to power the device. Such devices are not practical in low resource environments. As a consequence, it is the goal of this Thesis to develop a three-dimensional, multiplexed assay chip using nitrocellulose membranes. This device comprises of multiple layers of nitrocellulose membranes with defined fluidic channels. The multiple layers are bound together using double backed tape, and imbedded between …

Impedance Sensing Of N2a And Astrocytes As Grounds For A Central Nervous System Cancer Diagnostic Device, Fraser Traves Smith Grove

Master's Theses

This thesis utilizes previously described manufacturing and design techniques for the creation of a PDMS-glass bonded microfluidic device, capable of electrochemical impedance spectroscopy (EIS). EIS has been used across various fields of research for different diagnostic needs. The major aim of this thesis was to capture cancerous and non-cancerous cells between micron sized electrodes within a microfluidic path, and to complete analysis on the measured impedances recorded from the two differing cell types. Two distinct ranges of impedance frequency were analyzed – the α dispersion range, which quantifies the impedance of the membranes of the cells of interest, and the …

Design Of Experimentation To Systematically Determine The Interaction Between Electrospinning Variables And To Optimize The Fiber Diameter Of Electrospun Poly (D, L-Lactide-Co-Glycolide) Scaffolds For Tissue Engineered Constructs, Yvette S. Castillo

Master's Theses

Cardiac disease causes approximately a third of the deaths in the United States. Furthermore, most of these deaths are due to a condition termed atherosclerosis, which is a buildup of plaque in the coronary arteries, leading to occlusion of normal blood flow to the cardiac muscle. Among the methods to treat the condition, stents are devices that are used to restore normal blood flow in the atherosclerotic arteries. Before advancement can be made to these devices and changes can be tested in live models, a reliable testing method that mimics the environment of the native blood vessel is needed. Dr. …

Preparation And Characterization Of Electrospun Poly(D, L-Lactide-Co-Glycolide) Scaffolds For Vascular Tissue Engineering And The Advancement Of An In Vitro Blood Brain Barrier Model, Deven Chandrakant Patel

Master's Theses

Developing an in vitro Blood Brain Barrier model that will replicate the physiological, anatomical, and functional characteristics of the native BBB has gained significant attention. Such a model would enable prediction of the penetration of CNS targeting drug candidates across the BBB, allow pre-screening and optimization strategies to be developed for new drugs and gene delivery formulations, and permit research groups to further understand how a dysfunctional BBB is involved in the pathogenesis of several neurological diseases.

The Tissue Engineering laboratory at the California Polytechnic State University, San Luis Obispo is currently in the process of developing a dynamic in …

Characterization Of Raw Milk Fouling On Plate-Type Heat Exchangers Using Different Alloys And Cow Phenotypes, Stephen Ernest Nelson

Master's Theses

ABSTRACT

Characterization Of Raw Milk Fouling On Plate-Type Heat Exchangers Using Different Alloys And Cow PhenotypeS

Stephen Ernest Nelson

Milk and other dairy products are widely used in many households today. Milk is a popular beverage that is seen as a healthy alternative to other synthetic beverages such as soda pop and other sugar based drinks. It became law that milk, and milk products are pasteurized before its release to the general public (FDA 2003). Pasteurization is a thermal process where the intent is to lower the concentration of microorganisms in the milk to render it safe to drink with …

Viscoelastic Anisotropic Finite Element Mixture Model Of Articular Cartilage Using Viscoelastic Collagen Fibers And Validation With Stress Relaxation Data, Matthew Alexander Griebel

Master's Theses

Experimental results show that collagen fibers exhibit stress relaxation under tension and a highly anisotropic distribution. To further develop the earlier model of Stender [1], the collagen constituent was updated to reflect its intrinsic viscoelasticity and anisotropic distribution, and integrated with an existing mixture model with glycosaminoglycans and ground substance matrix. A two-term Prony series expansion of the quasi-linear viscoelastic model was chosen to model the viscoelastic properties of the collagen fibers. Material parameters were determined by using the simplex method to minimize the sum of squared errors between model results and experimental stress relaxation data of tissue in tension. …

A Kinetic Study Of Anti-Vegf-A Polyclonal Antibodies And Anti-Vegf-A Ssdna Aptamers, Heather A. Hedeen

Master's Theses

A new detection reagent that could possibly augment or replace antibodies research and diagnosis methods are aptamers. Aptamers are ssDNA, RNA or polypeptide constructs that function like active antibodies. Antibodies and aptamers both specifically bind to selected target molecules, and as such they enable the detection or targeting of the presence or absence of a specific antigen.

In order to ensure that ssDNA aptamers perform similarly to antibodies, anti-VEGF-A polyclonal antibody and anti-VEGF-A ssDNA aptamer were evaluated against vascular endothelial growth factor A (VEGF-A) using Surface Plasmon Resonance (SPR). It was hypothesized that the anti-VEGF-A aptamer had the same, if …

Improvement Of Statistical Process Control At St. Jude Medical's Cardiac Manufacturing Facility, Christopher Lance Edwards

Master's Theses

Sig sigma is a methodology where companies strive to reproduce results ending up having a 99.9996% chance their product will be void of defects. In order for companies to reach six sigma, statistical process control (SPC) needs to be introduced. SPC has many different tools associated with it, control charts being one of them. Control charts play a vital role in managing how a process is behaving. Control charts allow users to identify special causes, or shifts, and can therefore change the process to keep producing good products, free of defects.

There are many factories and manufacturing facilities having implemented …

Nitrocellulose Paper Based Microfluidic Platform Development And Surface Functionalization With Anti-Ige Aptamers, Jennifer Guerin Ward

Master's Theses

The purpose of this thesis project was to demonstrate the ability to utilize the capabilities of aptamers so that they may act as capture reagents for paper microfluidic devices. Several characterization experiments were conducted as a precursor before the final experimentation was performed. Paper characterization, manufacturing protocols for printing and heating, as well as 3D chip fabrication were all performed and analyzed. The results confirmed that the control of fluid through a 3D microfluidic device based in nitrocellulose is possible.

For the biochemistry portion of this thesis report, antibodies and aptamers were chosen to react with IgE, an antibody that …

The Characterization Of Biofilm Attachment To Metal Interfaces: Effects Of Substratum Properties, Marcel D. Mendes

Master's Theses

Bacteria are among the most abundant microorganisms on earth, and can be found in essentially every environment. When a clean surface is exposed to media containing planktonic bacteria, the bacterial cells will attach to the surface and aggregate to form what is known as a biofilm. Biofilms have been shown to negatively affect many industries including medical, industrial, and food science applications. While biofilms have been well characterized from a microbiology perspective, there has been much less research from a materials science standpoint. It is hypothesized that the material properties of the substratum (such as the micro-structure) have a significant …

A Stochastic Simulation Model Of Alarm Response Strategies On A Telemetry Floor, Tasneem M. Pishori

Master's Theses

The large quantity of alarms characteristic of clinical settings have resulted in nursing staff suffering from a phenomenon termed ‘alarm fatigue’. Alarm fatigue is desensitization via habituation – as these commonly heard noises cause caregivers to have delayed or no response to alarms. Alarm management was ranked number one on the annual top ten list of technology hazards afflicting healthcare institutions published by the ECRI Institute for 2012. Several patient safety organizations have established alarm fatigue as a priority concern, and are working to eradicate the issue from the healthcare environment by 2017. To better understand the problem, a simplified …

Development And Application Of A Portable System To Reliably Measure Grip Forces Using Thin-Film Force Sensors, Shane Vincent Tornifoglio

Master's Theses

Accurate tracking of hand grip force is an important consideration needed for a robust understanding in the study of human biomechanics. One aspect where it proves useful is in hand-arm vibration, such as from gripping a power tool. Depending on how firmly the user is gripping the tool, they may change their exposure levels to the tool vibration, which can lead to potential disorders such as Hand-Arm Vibration Syndrome (HAVS).

A small, battery powered portable force unit has been developed to supply power to, and condition, the signals from eight thin-film force sensors. This gives a better understanding of the …

A Comprehensive Methodology For Assessing Biomechanical Risks Associated With Hand Tool Use: Applied To Laparoscopic Surgical Instruments, Drew R. Seils

Master's Theses

Biomechanical risk factors are physical stressors that act on the neuromuscular structures of the human body and are present in all occupational settings. Repetition and intensity of tasks performed can magnify the effects of the biomechanical risks that a worker is exposed to.

After reviewing the current literature on ergonomics in laparoscopic surgery it was clear that a comprehensive approach to quantitatively reporting on the biomechanical risk factors associated with surgical hand tools had never been performed. Utilizing an opto-electronic motion capture system meant the exact surgeon posture was recorded during simulated surgical tasks. Electromyography was used to evaluate muscle …

Mechanical Properties Of Bone Due To Sost Expression: A 3-Point Bending Assessment Of Murine Femurs, Kainoa John Peterson

Master's Theses

Sclerostin, a protein coded for by the SOST gene, is an osteocyte-expressed negative regulator of bone formation. The absence of SOST in the genome may have an effect on bone formation both during skeletal maturation and full maturity. This study attempts to determine significant differences in the mechanical properties of bone that expresses SOST compared to bone that does not. One hundred femur samples from 6, 8, and 12 month old mice were obtained from Lawrence Livermore National Labs and loaded until failure using three-point bending. Results showed significant differences in treatment group effects for cross sectional area, yield force, …

Detection Of Sk2 Channels On Hippocampal Neurons, Jamie L. Maciaszek

Master's Theses

Calcium-activated small conductance potassium channels (SK) are crucial for synaptic plasticity, sleep, and learning and memory (Hammond, Bond et al. 2006; Cueni, Canepari et al. 2008; Lin, Lujan et al. 2008). Despite the recent progress on SK channel physiology, the precise spatial organization of SK channels in neurons has remained unknown. Such knowledge is critical as the subcellular distribution of SK channels is an important determinant of neuronal excitability. Currently, there are no techniques to image ion channel distribution quantitatively at the nanometer scale in living cells. Here, it is demonstrated that integration of natural toxins with single molecule atomic …

The Impact Of Increased Collateral Flow On Transverse Arteriolar Microvascular Tree Morphology, David Danzeiser

Master's Theses

The goal of this study was to understand how arteriogenesis impacts transverse arteriolar tree structure. The previous process involved a vascular casting technique that utilized black India ink as the casting agent and manual measurement of vessel morphology with ImageJ. This study decreased the complexity of the casted samples by using a casting compound called Microfil. Microfil’s viscosity can be adjusted and through experimentation, a viscosity was found that stopped at the capillary level, allowing only the arterial side of the circulation to be casted. A macro in ImageJ was written to help with morphological measurement by bundling vessel length …