Biomedical Engineering and Bioengineering Commons^™

Transcatheter Heart Valve Subassembly Device, Adam Aslam, Matthew Bezkrovny, Daniel Degree

Mechanical Engineering

No abstract provided.

A Comprehensive Review Of The Food And Drug Administration, The 510(K) Application Process, And Fda Certification For A Diagnostic Device, Taylor Davis

Biomedical Engineering

The company G-Force CRC LLC is currently experiencing the dichotomy of the FDA's conflicting role right now as they begin to approach FDA approval. G-Force CRC LLC is a small medical device company headquartered in San Diego, CA. The owner of the company, Dr. Ian Purcell, is an Otoneurologist apart of Alvarado Hospital. His medical practice mainly deals with patients who have balance disorders and therefore the devices that he has developed over the last 6+ years are primarily used to assist in the diagnosis of those balance disorders. G-Force CRC LLC was officially created in the summer of 2013 …

Micro Electrostatic Actuation Of A Silicon Diaphragm, Matthew W. Samples

Master's Theses

There are a number of applications, from hearing aids to microfluidic pumps, which utilize micro-scale actuating diaphragms. These MEMS (micro-electromechanical system) devices can be actuated by electrostatic forces, which utilize an induced electric field to pull two charged plates towards one another. Such devices were fabricated and electrostatic actuation of the diaphragms was performed to analyze its viability as a micro-speaker. The long-term performance of such products requires adequate diaphragm deflection to create audible pressure waves with relatively low maximum stresses to ensure a high cycle fatigue life. With these requirements, initial calculations and FEA (finite element analysis) were performed …

A Finite Element Analysis On The Viscoelasticity Of Postmenopausal Compact Bone Utilizing A Complex Collagen D-Spacing Model, Austin C. Cummings

Master's Theses

The nanoscale dimension known as D-spacing describes the staggering of collagen molecules, which are fundamental to the biphasic makeup of bone tissue. This dimension was long assumed to be constant, but recent studies have shown that the periodicity of collagen is variable. Given that the arrangement of collagen molecules is closely related to the degree of bone mineralization, recent studies have begun to look at D-spacing as a potential factor in the ongoing effort to battle postmenopausal osteoporosis. The theoretical models presented by previous studies have only opted to model a single collagen-hydroxyapatite period, so the creation of an intricate …

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 …

Development And Validation Of A Tibiofemoral Joint Finite Element Model And Subsequent Gait Analysis Of Intact Acl And Acl Deficient Individuals, Nicholas Czapla

Master's Theses

Osteoarthritis (OA) is a degenerative condition of articular cartilage that affects more than 25 million people in the US. Joint injuries, like anterior cruciate ligament (ACL) tears, can lead to OA due to a change in articular cartilage loading. Gait analysis combined with knee joint finite element modeling (FEM) has been used to predict the articular cartilage loading. To predict the change of articular cartilage loading during gait due to various ACL injuries, a tibiofemoral FEM was developed from magnetic resonance images (MRIs) of a 33 year male, with no prior history of knee injuries. The FEM was validated for …

Design And Fabrication Techniques Of Devices For Embedded Power Active Contact Lens, Errol Heradio Leon

Master's Theses

This thesis designed and fabricated various devices that were interfaced to an IC for an active contact lens that notifies the user of an event by detection of an external wireless signal. The contact lens consisted of an embedded antenna providing communication with a 2.4GHz system, as well as inductive charging at an operating frequency of 13.56 MHz. The lens utilized a CBC005 5µAh thin film battery by Cymbet and a manufactured graphene super capacitor as a power source. The custom integrated circuit (IC) was designed using the On Semiconductor CMOS C5 0.6 µm process to manage …

Self-Contained Breathing Apparatus For Firefighter With A Permanent Stoma, Jason Delgadillo, Aaron Wheeler, Zachary Wishbow

Biomedical Engineering

The purpose of this project was to create a unique SCBA (self-contained breathing apparatus) for a firefighter named Chris Gauer. This prototype consists of a SCBA headgear connected to a polycarbonate-formed stoma mask with a medical-grade sanitary silicone hose.

Evaluating The Effectiveness Of Cranial Molding For Treatment Of Positional Plagiocephaly Using Finite Element Analysis, Maziyar Keshtgar

Master's Theses

Since the advent of recommendations for placing infants in the supine position during sleep to reduce the incidence of sudden infant death syndrome, clinicians have noted an increase in the frequency of cranial asymmetry due to deformation of suture sections of the infants’ skulls as a result of constant concentrated stress in one area at the back of their head. This specific form of cranial deformation is known as positional plagiocephaly and its rate of occurrence has increased from 0.3% in 8.2% within the past 30 years.

Current treatments and methodologies for preventing and correcting positional plagiocephaly such as stretching …

Comparison Of Regular Ringer's Solution And Glucose Ringer's Solution On The Longevity Of The Hirudo Medicinalis' Retzius Cell, Nicole Arielle Peretti

Master's Theses

In 1882, Sydney Ringer, a professor of medicine at University College in London, experimented with the frog ventricle to better understand how each constituent of blood influences contraction. The ultimate goal was to create an artificial circulating fluid to use for the perfusion of isolated organs, in this case, a frog heart. Today, Ringer’s solution is still used in research for physiological studies requiring the survival and maintenance of specimens outside of their host bodies. One such example is the use of medicinal leech ganglia for electrophysiological measurements. In this thesis, I am comparing two Ringer’s solutions, original versus added …

Protective Effects Of Milk Phospholipids Against Uv-Induced Dna Damage In Human Skin Cells, Lan-Anh Nguyen

Master's Theses

Skin cancer is the most common type of cancer in the US. The American Academy of Dermatology estimated that more than 3.5 million new cases of skin cancer are diagnosed in the US each year and 1 in 5 Americans will likely to develop skin cancer in their life time. Most cases of skin cancer are caused by exposure to ultraviolet (UV) radiation from the sun. Some of the most common sunscreen ingredients are unstable and can form harmful radicals upon exposure to UV radiation. There is a strong clinical need for a more stable and effective sunscreen ingredient such …

Vascular Reactivity In Newly-Formed And Mature Arterialized Collateral Capillaries, Sara K. Hellstrom

Master's Theses

Peripheral arterial occlusive disease (PAOD) is a globally-prevalent cardiovascular disease in which atherosclerotic plaques narrow arterial lumen diameters and restrict blood flow to downstream tissues. The impact of these occlusions can be mitigated by collateral vessels that connect parallel arterial branches and act as natural bypasses to maintain perfusion. In animal models that lack collateral arterioles, capillaries that connect terminal arteriolar segments can arterialize and form functional collaterals following an ischemic event; however, in the early stages of development, vasodilation is impaired. We explored the mechanism of impaired vasodilation in arterialized collateral capillaries (ACCs) and pre-existing collaterals (PECs) by evaluating …

The Effect Of Artery Bifurcation Angles On Fluid Flow And Wall Shear Stress In The Middle Cerebral Artery, Zachary Ramey Jones

Master's Theses

Saccular aneurysms are the abnormal plastic deformation of veins and arteries that can lead to lethal thrombus genesis or internal hemorrhaging. Medication and surgery greatly reduce the mortality rates, but treatment is limited by predicting who will develop aneurysms. A common location for saccular aneurysm genesis is at the main middle cerebral artery (MCA) bifurcation. The main MCA bifurcation is comprised of the M1 MCA segment, parent artery, and two M2 segments, daughter arteries. Studies have found that the lateral angle (LA) ratio of the MCA bifurcation is correlated with aneurysm formation. The LA ratio is defined as the angle …

Smooth Muscle Cell Organization In The Stem Region Of The Gracilis Collateral Circulation In Balb/C Mice, Laura Lenae Burckhardt

Biomedical Engineering

Of the approximately 8 million Americans who suffer from ischemic peripheral arterial occlusive disease (PAOD), many present with intermittent claudication, or pain associated with exercise. Impaired vasodilation of resistance vessels is a potential explanation for this symptom. Occluded arteries can lead to increased flow through collateral vessels, which function as natural bypasses around the obstruction. This increase in blood flow and resulting shear stress can cause outward remodeling, or arteriogenesis, which improves the efficacy of collaterals. However, following femoral artery ligation in a mouse model of chronic ischemia, vasodilation in the stem region of collateral vessels is impaired at day …

Development, Characterization, And Optimization Of Process For Minimal Functional Barrier And Channel Width In Nitrocellulose Paper Microfluidic Diagnostic Platforms, Ryan Daniel Silva

Biomedical Engineering

A central goal of diagnostic microfluidics is to reduce the cost of diagnostic medicine by reducing the equipment and reagents needed to perform diagnostic tests. The literature has demonstrated that a wax printer can be used to pattern nitrocellulose paper with hydrophobic barriers to direct a sample in a defined reaction path, eliminating the need for external pumps and controllers. However, manufacturing methods for minimizing sample volume (and thus reagent volume) in a paper-diagnostic chip have not been well defined. In this work, we experimentally determine manufacturing processes for creating functional features of minimal size—effectively reducing the sample size and …

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 …

Investigating Hemodynamic Responses To Electrical Neurostimulation, Sean Youra

Master's Theses

Since the 1900s, the number of deaths attributable to cardiovascular disease has steadily risen. With the advent of antihypertensive drugs and non-invasive surgical procedures, such as intravascular stenting, these numbers have begun to level off. Despite this trend, the number of patients diagnosed with some form of cardiovascular disease has only increased. By 2030, prevalence of coronary heart disease is expected to increase approximately by 18% in the United States. By 2050, prevalence of peripheral arterial occlusive disease is expected to increase approximately by 98% in the U.S. No single drug or surgical intervention offers a complete solution to these …

A Rubric For Electrochemical Testing Of Metallic Biomaterials, Frederick G. De La Fuente

Master's Theses

Corrosion is a major factor for the failure of metallic medical implants. Testing a metal’s suseptability to corrosion prior to implantation is key to a successful implantation. Electrochemical processes were used in this study to evaluate the characteristics of corrosion of both AISI 316 stainless steel and titanium alloy Ti6Al4V, welded and non-welded. Linear, potentiodynamic, and cyclic polarization curves were produced by the PARC 2273 potentiostat showing the corrosion tendencies of the metals in four unique solutions 3.5% NaCl, 0.35% NaCl, phosphate buffered saline solution (PBS), and Butterfield phosphate buffered solution (BPS). The concentration of chloride ions in solutions affected …

Design, Characterization And Application Of A Multiple Input Stethoscope Apparatus, Spencer Geng Wong

Master's Theses

For this project, the design, implementation, characterization, calibration and possible applications of a multiple transducer stethoscope apparatus were investigated. The multi-transducer sensor array design consists of five standard stethoscope diaphragms mounted to a rigid frame for a-priori knowledge of their relative spatial locations in the x-y plane, with compliant z-direction positioning to ensure good contact and pressure against the subject’s skin for reliable acoustic coupling. When this apparatus is properly placed on the body, it can digitally capture the same important body sounds investigated with standard acoustic stethoscopes; especially heart sounds. Acoustic signal inputs from each diaphragm are converted to …

Microvascular Topology And Intravascular Endothelial Cell Labeling In The Gracilis Anterior Muscle Of Balb/C Mice, Paul Heckler Ii

Biomedical Engineering

Peripheral arterial occlusive disease (PAOD) affects approximately 200 million individuals globally. The major underlying cause of PAOD is an inflammatory disease known as atherosclerosis, which results from the build-up of low-density lipoproteins (LDL) in the sub-intimal space. This initiates a complex cascade of events that lead to plaque growth. Plaque growth can then expand into the lumen of the vessel and result in occlusion and/or thrombosis. Symptoms of the disease can include claudication, ulcers, and/or gangrene, although many patients are asymptomatic. Similar to other forms of ischemic disease, risk factors for PAOD include hypertension, diabetes, and smoking. Common treatments include …

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 …

Clear Circuit Contact Lens, Paul Hecker Ii, Phillip Azar, Alexander Do, Benny Ng, Errol Leon

Electrical Engineering

The clear active contact lens project aims to address safety and hazard awareness with an unexplored field of eye wear technology. With advancements in nanotechnology and the advent of circuits on contact lens, this project is one of the first research and development into this new field, following University of Washington and Google. The team focuses on the safety and biocompatibility of the contact lens for a comfortable ease of use. The designs push the limits of thin film printed technology with its pursuit of fine designs of 250μm antennas. The project streamlines the manufacturing process for a combination substrate …

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 …

2d Wireform Process Improvement, Katy Conlin, Carlo Ebora, Jordan Gamble

Mechanical Engineering

The body of this work has been created for Edwards Lifesciences in conjunction with senior project requirements. As such, the information produced and contained within is under a non‐disclosure agreement. As per request by sponsor, the body of the work will not be submitted to any outside parties, and the title page will serve as proof of completion.

Team Omnimouse, Derek J. Halman, Josh B. Porter, Steven A. Silver, Ian S. Stemper

Computer Engineering

INFORMATION, DATA, FIGURES AND DRAWINGS EMBODIED IN THIS DOCUMENT ARE STRICTLY CONFIDENTIAL AND ARE SUPPLIED ON THE UNDERSTANDING THAT THEY WILL NOT BE DISCLOSED TO THIRD PARTIES WITHOUT THE PRIOR WRITTEN CONSENT OF QUALITY OF LIFE PLUS.

Characterizing The Reproducibility Of The Properties Of Electrospun Poly(D, L-Lactide-Co-Glycolide) Scaffolds For Tissue-Engineered Blood Vessel Mimics, Toni M. Pipes

Master's Theses

“Blood vessel mimics” (BVMs) are tissue-engineered constructs that serve as in vitro preclinical testing models for intravascular devices. The Cal Poly Tissue Engineering lab specifically uses BVMs to test the cellular response to stent implantation. PLGA scaffolds are electrospun in-house using the current “Standard Protocol” and used as the framework for these constructs. The performance of BVMs greatly depends on material and mechanical properties of the scaffolds. It is desirable to create BVMs with reproducible properties so that they can be consistent models that ultimately generate more reliable results for intravascular device testing. Reproducibility stems from the consistency of the …

Development And Implementation Of Assessment Methods For Tissue-Engineered Blood Vessel Mimics, Tanner Stevenson

Biomedical Engineering

Coronary Artery Disease (CAD), the most prevalent form of heart disease, is the result of clogged or damaged coronary arteries and claims around 380,000 Americans annually. A common treatment for CAD involves placing a stent into the artery in order to open the lumen and support the native tissue—a procedure that drastically reduces patient recovery times in comparison to heart bypass surgery. However, stents do not always interact well with the body and require additions such as surface coatings or drug elution in order for additional biocompatibility. These additions necessitate extensive in vitro and in vivo testing which are expensive …

Functional Vasodilation Is Impaired In Arterialized Capillaries In The Spinotrapezius, Joshua P. Cutts

Biomedical Engineering

Ischemic diseases are the result of atherosclerotic plaques, which occlude conduit arteries. Ischemic disease in different tissues leads to different conditions, such as coronary artery disease (CHD), cerebrovascular disease (CVD), and peripheral arterial occlusive disease (PAOD). Patient vasculature architecture is variable; some patients having many collateral vessels, which are connect one arterial branch to another, and readily serve as natural bypass routes to atherosclerotic occlusions, to enlarge and provide blood flow to tissue distal to the occlusion. Patients with many natural collateral vessels are ischemia protected. Unfortunately, not all patients have collateral arterioles to remodel into conduit vessels and provide …

Sonar For The Visually Impaired, Anastasia Newark, Edwin Ng, Scott Terhorst

Biomedical Engineering

There are currently no inexpensive assistive devices that allow the visually impaired detect low hanging objects that are above waist height and may cause injury, such as a rope or tree branch. The challenge presented to the team by the Quality of Life Plus Lab (QL+) was to develop a Sonar Cane device that attaches to a traditional white cane to address this problem. This device must be lightweight, inexpensive to manufacture, have a long battery life, and accurately detect obstacles to prevent user injury.

Neuromodulation: Action Potential Modeling, Vladimir Ruzov

Master's Theses

There have been many different studies performed in order to examine various properties of neurons. One of the most important properties of neurons is an ability to originate and propagate action potential. The action potential is a source of communication between different neural structures located in different anatomical regions. Many different studies use modeling to describe the action potential and its properties. These models mathematically describe physical properties of neurons and analyze and explain biological and electrochemical processes such as action potential initiation and propagation. Therefore, one of the most important functions of neurons is an ability to provide communication …