Biomedical Engineering and Bioengineering Commons^™

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 …

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 …

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 …

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. …

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 …

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. …

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 …

Quantifying Proximal Conformability Of A Thoracic Aortic Stent Graft, Dylan Reinsdorf, Kendall Smith

Mechanical Engineering

This report is documentation of a Senior Project completed by Dylan Reinsdorf and Kendall Smith, in partial fulfillment of a Bachelor of Science in Mechanical Engineering at Cal Poly, San Luis Obispo. Medtronic Inc. approached the team with a need to quantify proximal conformity of stent grafts in the thoracic aorta. A solution was designed that included an aorta model that simulates clinical conditions, and a measurement method for stent graft conformability. This report documents all phases of the project, from sponsor requirements to final design to product realization and testing.

Polygrasp: Reach; Myoelectric Prosthetic Hand Iteration, Devon Patrick Augustus, Mighells Blaed Deuel, Ian Noel Fraser, Nicholas Philip Moesser

Mechanical Engineering

Amputations are a common occurrence in soldiers returning home who have suffered the effects of IED and munitions explosions. For upper limb amputees, trans-radial amputations are the most common. Traditional hook devices do not offer an adequate level of normalcy for users, prompting the use of myoelectric devices. While current myoelectric devices do offer a more natural experience, they come with a host of other problems that makes their adoption by service personnel not desirable or not permitted by the VA. PolyGrasp Reach seeks to reduce weight and cost and improve performance. This addresses several of the issues with devices …

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 …

Testing And Validation Of An Autostainer, Nicholas Hanne

Biomedical Engineering

Histology performed by Cal Poly students for research projects and labs are currently performed by hand using a dipping technique. This technique is time consuming, expensive, imprecise, and often unrepeatable. Central Coast Pathology donated a Dako Autostainer to the Biomedical Engineering Department that can perform immunohistological stains of up to 48 samples simultaneously using tightly controlled reagent volumes and incubation times. Protocols are programmed into the machine and can be repeated under the same conditions every time with minimal preparation and exposure to potentially dangerous reagents. The autostainer was repaired and validated by comparing PECAM & BBI stains performed on …

Esem Analysis Of Mice Femurs With Varying Sost Levels, Patrick K. Mcclay

Biomedical Engineering

This project’s goal was to analyze the properties of the cortical femur on 100 mice bones from Lawrence Livermore National Laboratory. Analysis was limited to imaging which determined the ratio of bone volume to total volume (BV/TV) and osteocyte lacunae density. Mice were altered to knock out their SOST gene: a negative regulator of bone formation. Twelve groups were created to differentiate their treatment, duration, and phenotype. Transgenic (TG) mice had an overexpression of the SOST gene: they carried a bacterial artificial chromosome. Mice with limb defects (DEF) were the offspring of two TG mice and carried twice the amount …

Corrosion Of Stainless Steel 316l And Astm F75 Cobalt Chromium Alloy During Immersion Testing In Silver Salt Solutions, Meagan Higgins

Materials Engineering

This study evaluates the potential effects of silver salts on biocompatible metals used for prostheses during the chemical reduction process to produce a silver antimicrobial layer on the metal’s surface. Samples of two biocompatible metals were obtained: Stainless Steel 316L and ASTM F75 Cobalt Chromium Alloy. Three different silver salts were also acquired: silver nitrate, silver sulfadiazine, and silver chloride. Specimens of each metal were cut to size using a 4-1/2 inch aluminum oxide, 40 grit, cut off wheel for metal, attached to a Dewalt Angle Grinder. The biocompatible metal samples were then subject to either Solution 1, water with …

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 …

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 …

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 …

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 …

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 …

Hydraulically Driven Mechanical Representation Of A Biological System, Andrea Argouarch, Michael Mceachern, Brandon Parham

Biomedical Engineering

No abstract provided.

Development And Characterization Of Plga And Eptfe Blood Vessel Mimics Using Gene Expression Analysis, Michael Gibbons, Sarah Ur

Biomedical Engineering

Tissue engineered blood vessels (TEBV’s) have the potential to act not only as a replacement for diseased vessels, but also as a testing platform for intravascular devices such as stents. To this end, the goal of this study was to develop protocols for the construction of TEBV’s composed of human vascular cells and either expanded polytetrafluoroethylene (ePTFE) or poly-lactic-co-glycolic acid (PLGA), as well as a protocol for gene expression in those TEBV’s. Initial experiments involved only human umbilical vein endothelial cells (HUVEC’s), but after low cell confluency and spreading in single-sodded vessels a second cell type, human umbilical vein smooth …