Biomedical Engineering and Bioengineering Commons^™

Development Of An In Vitro 3-Dimensional Co-Culture Human Colorectal Cancer Model In Microfluidic Devices, Abby Jens

Master's Theses

Colorectal cancer is the second most common cause of cancer-related deaths in the United States, with the relative 5-year survival rate for distant stage cancer being only 14%. The most common treatment for colorectal cancer is with chemotherapeutic drugs; however, the discovery of these drugs is costly, time-consuming, and often requires the use of animal models that do not yield results that translate to clinical trials. Due to these shortcomings, researchers seek to develop physiologically relevant in vitro tumor models that more accurately mimic the tumor microenvironment for cheaper and faster high-throughput drug screening. The aim of this research was …

Comparison Of Scanning Electron Microscopy And Confocal Laser Microscopy For Tissue Surface Roughness Characterization, Tarnvir Dhaliwal

Master's Theses

It was found that the measurements captured by confocal microscopy and scanning electron microscopy had a statistically significant difference for bovine tissue. There was not a statistically significant for porcine and poultry tissue.

The intent of the study is to perform a comparative study to examine efficacy of two distinct technologies for a singular purpose: tissue surface roughness characterization. The two technologies compared are a confocal reflectance microscope and a scanning electron microscope. The comparison was made by comparing two surface roughness parameters [Ra and Rq] within ImageJ.

The study examined three different animal species [porcine, bovine, and poultry] to …

Live Cell Imaging Gas Control, Elsa M. Bean, Brady C. Berg, Abby A. Jens

Biomedical Engineering

The following document outlines the entire process for designing and manufacturing a Live Cell Imaging Gas Control subsystem in tandem with the Heated Stage subsystem to make a CO₂ and temperature-controlled chamber for use with the Olympus IX73P2F Microscope. It highlights the current literature and patents surrounding live cell imaging and touches on the existing live cell imaging setups currently being used by other entities. Following this, it defines the scope of the project, key customer requirements, and engineering specifications to ensure the design meets all the needs of its users. This document includes project planning steps to establish …

Investigation Of Experimental Variation Of Bovine Sphingomyelin As A Novel Ingredient For Ultraviolet Protection, Esther Chen

Master's Theses

Skin cancer is a prevalent disease that globally affects 2-3 million people per year [1]. This number is expected to grow tenfold as depletion of the ozone layer contributes to harsher rays reaching Earth’s surface [2]. A common way to protect against those ultraviolet waves is to apply sunscreen, however, recent reports call into question the safety of some active ingredients as they can enter through the skin into the bloodstream [3]. This thesis aims to investigate an alternative solution that uses bovine sphingomyelin (BSM) as photoprotective solution against UV irradiation.

In order to evaluate the effectiveness of BSM against …

Evaluation Of Human Umbilical Vein Endothelial Cells In Blood Vessel Mimics Through Changes In Gene Expression And Caspase Activity, Conor Charles Hedigan

Master's Theses

Blood vessel mimics (BVMs) are simple tissue engineered blood vessel constructs intended for preclinical testing of vascular devices. This thesis developed and implemented methods to characterize two of these components. The first aim of this thesis investigated the effect of cell culture duration and flow conditions on endothelial cell gene expression, especially regarding endothelial-to-mesenchymal transition (EndMT). A trend of decreased endothelial marker gene expression and increased mesenchymal marker gene expression would indicate EndMT. qPCR analysis revealed that increased cell culture duration did not result in EndMT, and in fact increased endothelial marker expression as cell culture duration increased. Disturbed flow …

Automated Microscope Stage, Corin Nishimoto, Alison Flesch, Theo Anastos

Biomedical Engineering

This document seeks to describe the background information, customer requirements, design specifications, indications for use, selected materials, proposed budget, prototypes, final design, manufacturing processes, and testing methods regarding the CellOptimizer automated microscope stage product.

Computer-Aided Diagnoses (Cad) System: An Artificial Neural Network Approach To Mri Analysis And Diagnosis Of Alzheimer's Disease (Ad), Berizohar Padilla Cerezo

Master's Theses

Alzheimer’s disease (AD) is a chronic and progressive, irreversible syndrome that deteriorates the cognitive functions. Official death certificates of 2013 reported 84,767 deaths from Alzheimer’s disease, making it the 6th leading cause of death in the United States. The rate of AD is estimated to double by 2050. The neurodegeneration of AD occurs decades before symptoms of dementia are evident. Therefore, having an efficient methodology for the early and proper diagnosis can lead to more effective treatments.

Neuroimaging techniques such as magnetic resonance imaging (MRI) can detect changes in the brain of living subjects. Moreover, medical imaging techniques are the …

Skin Tone Tracking Device (Chromaband), Ziyang Bian

Computer Engineering

It’s long been said that your skin is a window into your health and with many illnesses the first signs of trouble actually show up in your skin. So if we have this natural warning system, then why isn’t anyone able to effectively use it to predict changes in our health? The problem is that currently there is no reliable way to accurately measure the change in skin tone and how these changes may or may not change with variations in health. This project’s aim is to design and develop a device that will record the changes in a user’s …

Measuring Blood Flow In The Skeletal Muscle Microcirculation Using Laser Speckle Flowmetry, Kenneth Howard Gouin Iii

Biomedical Engineering

The presence of a native collateral circulation, which serves as a natural bypass for blood flow around an occlusion, improves prognosis for patients with ischemic diseases, such as peripheral arterial occlusive disease (PAOD). However, not all patients have a native collateral circulation, and animal models suggest a genetic basis for this variability. In mice, such as the BALB/c, that lack native arteriolar collaterals, neocollateral formation from capillaries that connect two arterial trees can occur after arterial occlusion, resulting in reperfusion of the ischemic watershed. Immature arterialized collateral capillaries (ACCs) at 7 days post arterial occlusion do not vasodilate in response …

Characterization Of Two Vernier-Tuned Distributed Bragg Reflector (Vt-Dbr) Lasers Used In Swept Source Optical Coherence Tomography (Ss-Oct), Greg M. Bergdoll

Master's Theses

Insight Photonic Solutions Inc. has continued to develop their patented VT-DBR laser design; these wavelength tunable lasers promise marked image-quality and acquisition time improvements in SS-OCT applications.

To be well suited for SS-OCT, tunable lasers must be capable of producing a highly linear wavelength sweep across a tuning range well-matched to the medium being imaged; many different tunable lasers used in SS-OCT are compared to identify the optimal solution.

This work electrically and spectrally characterizes two completely new all-semiconductor VT-DBR designs to compare, as well. The Neptune VT-DBR, an O-band laser, operates around the 1310 nm range and is a …

Nerve Fiber Diameter Measurements Using Hematoxylin And Eosin Staining And Brightfield Microscopy To Assess The Novel Method Of Characterizing Peripheral Nerve Fiber Distributions By Group Delay, Jorge Arturo Vazquez

Master's Theses

Peripheral neuropathies are a set of common diseases that affect the peripheral nervous system, causing damage to vital connections between various parts of the body and the brain and spinal cord. Different clinical conditions are known to selectively impact various size nerve fibers, which often makes it difficult to diagnose which peripheral neuropathy a patient might have. The nerve conduction velocity diagnostic test provides clinically useful information in the diagnosis of some peripheral neuropathies. This method is advantageous because it tends to be minimally invasive yet it provides valuable diagnostic information. However, this test does not determine characteristics of peripheral …

Developent Of A Phospholipid Encapsulation Process For Quantum Dots To Be Used In Biologic Applications, Logan Grimes

Master's Theses

The American Cancer Society predicts that 1,665,540 people will be diagnosed with cancer, and 585,720 people will die from cancer in 2014. One of the most common types of cancer in the United States is skin cancer. Melanoma alone is predicted to account for 10,000 of the cancer related deaths in 2014. As a highly mobile and aggressive form of cancer, melanoma is difficult to fight once it has metastasized through the body. Early detection in such varieties of cancer is critical in improving survival rates in afflicted patients. Present methods of detection rely on visual examination of suspicious regions …

Smooth Muscle Cell Organization In The Stem Region Of The Gracilis Collateral Circulation, Amanda Krall

Biomedical Engineering

Many patients who suffer from the ischemic Peripheral Arterial Occlusive Disease (PAOD) experience intermittent claudication, which can be attributed to impaired vasodilation. Collateral vessels are the primary site of resistance to blood flow downstream; therefore maximizing vasodilation in collaterals is crucial for efficient circulation. Collaterals function as natural bypasses around the occluded arteries and the increase in flow into these vessels causes them to outwardly remodel into conduit vessels. However, functional vasodilation in the stem region of collateral vessels is impaired at day 7 following femoral ligation, which can be attributed to smooth muscle cell malfunction. However, the increase in …

Material Differences In Equine Cortical And Trabecular Bone, Ryan B. Allen

Master's Theses

A greater understanding of bone materials would be beneficial in creating more accurate computer models and in the making of biomedical products involving bone. This study set out to determine whether cortical and trabecular bone are two separate materials, or whether they are the same material with a variance in porosity. To answer this question, samples were taken from different sections of the equine metacarpus, underwent densitometry analysis and were statistically analyzed. The majority of results suggest that the material is the same between varying densities of bone and thus the same between cortical and trabecular bone. These particular results …

Fluorescence Characterization Of Quantum Dots For Use As Biomarkers, Logan M. Grimes

Materials Engineering

Fluorescence profiles of quantum dots (QDs) were characterized to select the ideal QDs for encapsulation in phospholipids for use as biomarkers to selectively adhere to cancer cells. QDs were synthesized and extracted 0, 30, 60, and 90 seconds after precursor compounds were mixed. These extractions were isolated by extraction time. Portions from each vial were coated in a zinc sulfide shelling procedure, leaving at least half of the QD solution unshelled. These samples were characterized over four days to monitor fluctuations in fluorescence. This was done utilizing an Ocean Optics spectrometer in conjunction with Spectra Suite software. The central wavelength, …

Microcapsule Containing Lactic Acid Bacteria For Treatment Of Peptic Ulcers, Brandon Jerome Hinkel

Master's Theses

Probiotics are marketed throughout the world to promote the health of the consumer by improving the microorganisms that normally occur in the intestinal tract (Tannock, 1997). It has also been suggested that probiotics can prevent pathogen infections by adhering to the intestinal mucosa (Lee, Lim, Teng, Ouwehand, Tuomola, & Salminen, 2000). While probiotics can be delivered to the infected areas in multiple fashions, microencapsulation is a newer form of delivering probiotics straight to the infected area. A whey protein microcapsule is thought to protect the probiotics from stomach acid and delivers the treatment to the affected area. To ensure this …

Tracking Points On A Pacing Lead In A Beating Heart, Avinash Ramesh Varma

Master's Theses

Heart failure is a common condition during which the pumping action of the heart is affected because the heart does not contract or relax properly. Heart failure affects about 5 million Americans, with 550,000 new cases diagnosed each year. Cardiac resynchronization therapy (CRT) is used to treat symptoms and other complications associated with a heart failure. While performing CRT, Implantation of a pacing lead in the left ventricle of the heart is a very challenging surgical procedure performed with fluoroscopy. The target location is often difficult to reach through the tortuous coronary venous anatomy, which varies greatly among individuals. Placement …

A Microfluidic Pretreatment Isoelectric Focusing Dc-Field Assisted H-Filter For The Separation Of Charged Particles, Cameron Sean Carroll

Biomedical Engineering

Microfluidic devices are small portable diagnostic chips that allow for analysis of a biologic sample at relatively low cost. This makes them ideal for settings where a hospital is unavailable. The microfluidic pretreatment isoelectric focusing DC-field assisted H-filter is a device that allows for the separation of differently charged particles in a biologic sample. It does this by employing the concepts of diffusion, electrophoresis, and isoelectric focusing. This is perfect for isolation of a desired analyte or separation of waste from a sample in order to achieve better diagnostic results. The device was first modeled mathematically and visually using Comsol. …

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 …

Development Of A Blood Flow Measurement Protocol Using Particle Image Velocimetry, Jennifer Chi-Ying Go

Biomedical Engineering

Peripheral Arterial Occlusive Disease (PAOD) is an acquired inflammatory disease where a peripheral artery becomes occluded due to the buildup of atherosclerotic plaques. In patients that possess collateral arteries, an occlusion can lead to shear induced outward remodeling, arteriogenesis, of these collaterals, partially restoring blood flow. However, newly remodeled collaterals exhibit reduced functional vasodilation, which may impair normal activity, such as ambulation. To model chronic ischemia and arteriogenesis in collaterals, a femoral artery ligation in a murine hindlimb is commonly performed. Previous efforts by our group involved measurements of collateral artery diameter to assess the impact of arteriogenesis on functional …

Protective Effects Of Milk Phospholipids Against Uv Photodamage In Human Skin Equivalents, Zyra Achay

Master's Theses

The ultraviolet (UV) spectrum has been known to cause damage to skin in varying degrees. UVB radiation (290-320 nm) in particular, has been proven to be highly mutagenic and carcinogenic in many animal experiments compared to either UVA or UVC. The alarming rate of increase in skin cancer incidence has prompted many investigators to pursue other alternatives to sunscreens including changes in lifestyle habits and dietary consumption in order to boost our efforts in tackling this widespread disease. Previous studies employing confocal reflectance, MTT assay and histology suggest that milk phospholipids may possess protective properties against UVB-mediated damage but the …

Determining A Method For Rendering Low Cost Cdse(Zns) Core(Shell) Quantum Dots Aqueous Soluble Via Amphiphilic Polymer Wrapping, Patrick Mcbride

Materials Engineering

Herein is described the procedure of two amphiphilic polymer wrapping techniques that may be employed for obtaining aqueous soluble quantum dots (QDs) for use in biological fluorescent imaging applications. The advent of QDs has led to new nanoscale fluorescent materials that exhibit unparalleled quantum yields (QYs), high resistance to photobleaching, tunable emissions, and
absorption over a large optical range. However, the QD synthesis employed here at Cal Poly to obtain bright, photostable CdSe(ZnS) core(shell) QDs involves the use of organic solvents and surfactants, leading to hydrophobic QDs. Since all of biology relies on aqueous solubility, this hydrophobicity creates a major …

Development Of An In-Vitro Hyperglycemic Tissue Engineered Blood Vessel Mimic, Brian C. Wong

Biomedical Engineering

No abstract provided.

Studying Milk Coagulation Kinetics With Laser Scanning Confocal Microscopy, Image Processing, And Computational Modeling, Richard Joseph Hennessy

Master's Theses

The kinetics of milk coagulation are complex and still not well understood. A deeper understanding of coagulation and the impact of the relevant factors would aid in both cheese manufacturing and also in determining the nutritional benefits of dairy products. A method using confocal microscopy was developed to follow the movement of milk fat globules and the formation of a milk protein network during the enzyme-induced coagulation of milk. Image processing methods were then used to quantify the rate of coagulation. It was found that the texture of the protein network is an indicator of the current status of the …

Characterization And Analysis Techniques Of A Dynamic In Vitro Blood-Brain Barrier Model, Ryan Everett Woodhouse

Biomedical Engineering

The blood-brain barrier (BBB) is responsible for maintaining the sensitive environment required by the brain. Although the BBB is necessary for proper functioning of the brain, it acts as an obstacle for doctors attempting to treat neurological disease. For a drug to act upon the brain, it must first pass through the discriminating BBB. For this reason, much research has been performed in recent years in order to create an in vitro model of the BBB on which drugs targeted for the central nervous system may be tested. The main goal of this project is to create an in vitro …

Can Spr Be Used To Interrogate The Double Layer Of Nacl, Brandon Kawula

Biomedical Engineering

Solutions of reagent grade salt .1, .01, .001, .0001, .00001M were run through a SPR to see if SPR had enough resolution to detect the formation of the electric double layer. We found that NaCl did in fact return a detectable signal. The signal shape seems to depend on concentration. While more study may need to be done to get definite information it looks like SPR can interrogate the double layer.

Multi-Frequency Processing For Lumen Enhancement With Wideband Intravascular Ultrasound, Rory A. Carrillo

Master's Theses

The application of high frequency ultrasound is the key to higher resolution intravascular ultrasound (IVUS) images. The need to further improve the IVUS spatial resolution may drive the transducer center frequency even higher than the current 40 MHz range. However, increasing the center frequency may be challenging as it leads to stronger scattering echoes from blood. The high level of blood scattering echoes may obscure the arterial lumen and make image interpretation difficult. Blood backscatter levels increase with transmission center frequency at a much greater rate compared to arterial tissue. These different frequency dependencies provide a potential method to distinguish …

Laser Scanning Confocal Microscopy (Lscm): An Application For The Detection Of Morphological Alterations In Skin Structure, Shea C. Smith

Master's Theses

Laser scanning confocal microscopy (LSCM) is an optical imaging technique that provides improved resolution and sensitivity over conventional methods of optical microscopy. However, the cost of most commercial LSCM systems exceeds the financial limitations of many smaller laboratories. The design of a custom LSCM created at a fraction of the cost of a commercial model is discussed in this paper.

The increase in the incidence rate of skin cancer in the world today is alarming, as such, it is essential to provide an early, rapid and effective method for in vivo diagnostics of human skin tissue. LSCM is capable of …

The Electrical Properties Of Human Tissue For The Diagnosis And Treatment Of Melanoma Skin Cancer, Glenn Cameron Stante

Master's Theses

This thesis discusses the research, experimental methods, and data gathered for the investigation of a novel method for the diagnosis of melanoma skin cancer. First, a background about human skin tissue is presented. Then, a detailed description of melanoma along with current diagnosis techniques and treatment options are presented. In the experimental methods, the electrical properties of several types of tissue were analyzed, the purpose of which was to discover if a tissue type can be distinguished by its electrical properties alone. This would allow for the diagnosis of melanoma to be done by examining the electrical properties of the …