Biomedical Engineering and Bioengineering Commons^™

Eeg Characterization During Motor Tasks That Are Difficult For Movement Disorder Patients, Adam Joshua Aslam

Master's Theses

Movement disorders are a group of syndromes that often arise due to neurological abnormalities. Approximately 40 million Americans are affected by some form of movement disorder, significantly impacting patients’ quality of life and their ability to live independently. Deep brain stimulation (DBS) is one treatment that has shown promising results in the past couple decades, however, the currently used open-loop system has several drawbacks. By implementing a closed-loop or adaptive DBS (aDBS) system, the need for expensive parameter reprogramming sessions would be reduced, side-effects may be relieved, and habituation could be avoided. Several biomarkers, for example signals or activity derived …

Interfacing A Hirudo Medicinalis Retzius Cell With Insulated Gate Of Mosfet, Rachel M. Smith

Master's Theses

Much work has been done to study the external stimulation of nervous tissue as well as the transmission of neural signals to electronics. Peter Fromherz was one of the pioneers in this area of electrophysiology, with a series of experiments in the 1990s that aimed to characterize and optimize the interface between neural tissue and transistors. In this thesis, Kurt Sjoberg and I interfaced a Retzius cell isolated from a Hirudo medicinalis ganglion with the insulated gate of a MOSFET. The goal was to see change in membrane potential that could be related Fromherz’s original 1991 work. Our experimental setup …

Sex Differences In Collateral Remodeling Following Hindlimb Arterial Occlusion, Laura Burckhardt

Master's Theses

Clinical evidence indicates a higher incidence of peripheral arterial occlusive disease and associated likelihood of critical limb ischemia in women, as well as worse prognosis and decreased survival post myocardial infarction. Therefore, understanding the possible differences in underlying vascular compensation mechanisms is crucial. With arterial occlusions, necrosis and tissue injury can be naturally mitigated by the collateral circulation, improving patient prognosis. Previous sex-comparison studies describing differences in vascular remodeling are inconsistent. Therefore, the aim of this study was to describe the effect of arterial occlusion on collateral remodeling in healthy male and healthy reproductive-stage female mice. At 7 days following …

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 …

Sex Differences And The Effects Of Exercise Training On Functional Vasodilation Following Arterial Occlusion In The Balb/C Mouse Spinotrapezius, Britta Nelson

Master's Theses

Peripheral arterial occlusive disease (PAOD) often presents as intermittent claudication, which may be caused by impaired vasodilation. Impairment of resistance vessels may contribute to the pathogenesis of PAOD, and explain the poor correlation between resting blood flow and limb function. Collateral function following arterial occlusion is not well defined, however collaterals and arterialized collateral capillaries (ACCs) in male and female animal models exhibit impaired vasodilation following arterial occlusion, which can potentially be improved with exercise training. Furthermore, resistance vessels in the ischemic tree and stem are likely involved in the pathogenesis of PAOD, however the relative importance of each is …

Influence Of Fibroblasts On Functional Arteriogenesis In A Murine Chronic Hindlimb Ischemia Model, Ashli A. Santos

Biomedical Engineering

Peripheral arterial occlusive disease (PAOD) occurs when there is a narrowing or blockage – usually a buildup of plaque - within the arteries that reduces blood flow to tissues which can chronic ischemia. As with most diseases, early detection and proactive treatment are important to maximize prognosis. Exercise effectively treats PAOD, but due to ischemic pain in the limbs, or intermittent claudication (IC), exercise can become painful and difficult. Due to the buildup of plaque, occlusions create an ischemic environment that changes the pressure distribution in collateral networks and increases the shear stress in transverse collaterals. Those two responses signal …

Identifying And Reducing Variability, Improving Scaffold Morphology, And Investigating Alternative Materials For The Blood Vessel Mimic Lab Electrospinning Process, Evan M. Dowey

Master's Theses

The work of the Cal Poly Tissue Engineering Lab is primarily focused on the fabrication, characterization, and improvement of “Blood Vessel Mimics” (BVMs), tissue engineered constructs used to evaluate cellular response to vascular medical devices. Currently, cells are grown onto fibrous, porous tubes made using an in-house electrospinning process from PLGA, a biocompatible co-polymer. The adhesion and proliferation of cells in a BVM is reliant on the micro-scale structure of the PLGA scaffold, and as such it is of great importance for the electrospinning process to consistently produce scaffolds of similar morphologies. Additionally, it has been shown that cell proliferation …

Emg-Driven Inverse Dynamic Analysis Of Knee Contact Forces During Gait And Cycling Using Opensim, Megan V. Pottinger, Katherine Mavrommati, Scott Hazelwood, Stephen M. Klisch

Biomedical Engineering

Joint contact forces determine the loading experienced by cartilage tissue and, thus, may be used to predict risk of cartilage tissue damage and osteoarthritis (OA). Participating in low impact and/or non-weight bearing activities such as cycling may help reduce knee OA risk by limiting forces exerted during exercise [1]. Cycling is a common recommendation for rehabilitative or fitness sustainment exercise for select patients [1]. Although knee joint contact forces have been directly measured in gait and cycling using instrumented knee implants [2,3] and calculated in gait using EMG-driven analysis [4]; they have not been calculated in cycling using EMG-driven analysis. …

Principal Component Analysis Of Gait And Cycling Experiments: Crosstalk Error Reduction And Corrected Knee Axes, Jordan Skaro, Harsh Goel, Scott Hazelwood, Stephen M. Klisch

Biomedical Engineering

Crosstalk is a leading source of error in motion analysis [1-2]. Due to incorrect flexion axis direction that develops from marker placement error, crosstalk results in a strong, anatomically incorrect correlation between flexion-extension (FE) and adduction-abduction (AA) motions [1-2]. Thus, crosstalk limits the ability of biomechanical models to reflect the “true” motion of the knee. Principal Component Analysis (PCA) has been proposed as a post-hoc correction for crosstalk in prior gait studies [1-2]; however, previous studies have not proposed a method to determine PCA corrected knee axes. Further, it is not clear how PCA should be implemented in motion analysis …

Elbow And Shoulder Joint Torques Are Correlated With Body Mass Index But Not Game Pitch Count In Youth Baseball Pitchers, Jim Douglas Darke, Eshan M. Dandekar, Arnel Aguinaldo, Scott Hazelwood, Stephen M. Klisch

Biomedical Engineering

The number of ulnar collateral ligament (UCL) reconstructive (i.e. “Tommy John”) surgeries performed on youth baseball pitchers have more than doubled since 2000 [1]. Routinely pitching while fatigued is considered a leading factor associated with UCL injuries; adolescent pitchers who had elbow or shoulder surgery were 36 times more likely to have routinely pitched with arm fatigue [1]. MLB/USA Baseball Pitch Smart guidelines limit 9-10 yr. old pitchers to a maximum 75 pitches per game, a figure based on long-term studies related to injury prevention [2]. Several studies have shown that pitching kinematics (e.g. elbow flexion/extension and pronation/supination, scapulothoracic internal-external …

Knee Biomechanics During Cycling Are Similar For Normal Weight And Obese Subjects, Juan D. Gutierrez-Franco, Jordan Skaro, Scott Hazelwood, Stephen M. Klisch

Biomedical Engineering

Osteoarthritis (OA) is a degenerative disease of cartilage and bone tissue, and is linked to more than 70% of total hip and knee replacements [1]. In 1994 the direct and indirect costs of OA in the United States were $155 billion [2] and in 2006 OA resulted in approximately $10.5 billion in hospital charges [3]. Obesity is a risk factor for OA [1, 3, 4], likely due to increased knee loading [5, 6] and varus malalignment [7] in gait. Seated cycling has been recommended as a weight-loss exercise with lower knee loads than walking or jogging [8]. However, lack of …

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 …

Poly Drop, Zachary T. Scott, Lilly J. Paul

Computer Engineering

Poly Drop is a software interface to control an Open Drop digital micro-fluidics system. We obtained a hardware system from Gaudi labs. Our task was to create a Graphical User Interface that made the control of the device easier and more automated for better testing. We created software that had 3 parts: a control GUI, arduino code to control the hardware, and Image Analysis that gives the user information such as location and color of liquid drops as they move across the electrode grid of the Open Drop system. The GUI was developed using Java Swing. The communication between the …

Redesign Of The Medtronic Kyphon Bone Cement Mixer For Vertebral Compression Fractures, Mollie Benson, Sarah Freesemann, Aj Konnath, Benjamin Murray

Biomedical Engineering

The complete senior project report was submitted to the project advisor and sponsor. The results of this project are of a confidential nature and will not be published at this time.

Development And Characterization Of Tissue Engineered Blood Vessel Mimics Under "Diabetic" Conditions, Shelby Gabrielle Kunz

Master's Theses

The development of tissue engineered blood vessel mimics for the testing of intravascular devices in vitro has been established in the Cal Poly tissue engineering lab. Due to the prevalence of cardiovascular disease in diabetic patients and minimal accessible studies regarding the interactions between diabetes and intravascular devices used to treat vascular disease, there is a need for the development of diabetic models that more accurately represents diabetic processes occurring in the blood vessels, primarily endothelial dysfunction. This thesis aimed to create a diabetic blood vessel mimic by implementing a high glucose environment for culturing human endothelial cells from healthy …

Isolation And Culture Of Myofiber-Derived Cells From The Extensor Digitorum Longus Muscle, Ethan M. Tietze

Biomedical Engineering

Peripheral arterial occlusive disease (PAOD) involves distal artery occlusion by atherosclerotic plaques, which restricts blood flow and leads to ischemia in downstream tissues. Increased blood flow through preexisting collateral vessels leads to increased shear stress that triggers an outward remodeling of the vessel called arteriogenesis. In some cases this natural compensatory mechanism is able to sufficiently restore blood flow following arterial occlusion. However, for many individuals this process is insufficient to relieve peripheral ischemia, and patients experience intermittent claudication, or limb pain with locomotion or exercise. Without treatment, reduced blood flow can lead to tissue necrosis and potentially amputation. The …

Fluid Flow Characterization And In Silico Validation In A Rapid Prototyped Abdominal Aortic Aneurysm Model, Dean Thomas Wampler

Master's Theses

Aortic aneurysms are the 14^th leading cause of death in the United States. Annually, abdominal aortic aneurysm (AAA) ruptures are responsible for 4500 deaths. There are another 45,000 repair procedures performed to prevent rupture, and of these approximately 1400 lead to deaths. With proper detection, the aneurysm may be treated using endovascular aneurysm repair (EVAR). Understanding how the flow of the blood within the artery is affected by the aneurysm is important in determining the growth of the aneurysm, as well as how to properly treat the aneurysm. The goal of this project was to develop a physical construct …

Application Of Argon Plasma Technology To Hydrophobic And Hydrophilic Microdroplet Generation In Pdms Microfluidic Devices, Brennan P. Graham

Master's Theses

Abstract Application of Argon Plasma Technology to Hydrophobic and Hydrophilic Microdroplet Generation in PDMS Microfluidic Devices Brennan Graham Microfluidics has gained popularity over the last decade due to the ability to replace many large, expensive laboratory processes with small handheld chips with a higher throughput due to the small channel dimensions [1]. Droplet microfluidics is the field of fluid manipulation that takes advantage of two immiscible fluids to create droplets from the geometry of the microchannels. This project includes the design of a microfluidic device that applies the results of an argon plasma surface treatment to polydimethylsiloxane (PDMS) to successfully …

Final Design Report: Polymer Fatigue Characterization Test Method, Wyatt Ayling, Tyler Price, Brandon Stell, Michela Upson

Mechanical Engineering

Polylogix is a team dedicated to the design, build, and testing of a fatigue machine to simulate cyclic loading on a biomedical polymer. This project is sponsored by Endologix, Inc. to provide test data characterizing mechanical material properties of various formulations of polymer used in abdominal aortic aneurysm surgeries. With this project goal, the machine must be able to test the polymer at body conditions; these include a testing temperature of 37°C and a cycling frequency ranging from 1 Hz to 10 Hz. This report proposes the following solution to this design challenge: an AC motor-driven mechanism utilizing a planetary …

The Impacts Of Arterial Occlusion, Sex, And Exercise On Arteriogenesis And Functional Vasodilation, Megan Tze-Mei Chu

Master's Theses

The most frequent clinical presentation of peripheral arterial occlusive disease (PAOD) is intermittent claudication, which may be caused by impaired vasodilation. Patients demonstrate both local and systemic impairments in vasodilation, but as the collateral circulation is the primary site of resistance to the ischemic zone, impaired collateral vasodilation would have the greatest potential to induce claudication. Collateral function following arterial occlusion is not well defined, but immature collaterals may demonstrate impaired vasodilation in animal models, although this is potentially improved with exercise training. Furthermore, as females exhibit poorer physical function with ischemia and less improvement with therapeutic exercise, there appears …

Functional 3-D Cellulose And Nitrocellulose Paper-Based, Microfluidic Device Utilizing Elisa Technology For The Detection/Distinction Between Hemorrhagic And Ischemic Strokes, Alicia Leanne Holler

Master's Theses

The purpose of this thesis project is to demonstrate and evaluate an enzyme-linked immunosorbent assay (ELISA) on a paper microfluidic device platform. The integration of ELISA technology onto paper microfluidic chips allows for a quantitative detection of stroke biomarkers, such as glial fibrillary acidic protein (GFAP). Dye experiments were performed to confirm fluid connectivity throughout the 3D chips. Several chip and housing designs were fabricated to determine an optimal design for the microfluidic device. Once this design was finalized, development time testing was performed. The results confirmed that the paper microfluidic device could successfully route fluid throughout its channels at …

Quantifying Parkinson's Disease Symptoms Using Mobile Devices, Charles R. Aylward

Master's Theses

Current assessments for evaluating the progression of Parkinson’s Disease are largely qualitative and based on small sets of data obtained from occasional doctor-patient interactions. There is a clinical need to improve the techniques used for mitigating common Parkinson’s Disease symptoms. Available data sets for researching the disease are minimal, hindering advancement toward understanding the underlying causes and effectiveness of treatment and therapies. Mobile devices present an opportunity to continuously monitor Parkinson’s Disease patients and collect important information regarding the severity of symptoms. The evolution of digital technology has opened doors for clinical research to extend beyond the clinic by incorporating …

Nanoindentation Techniques For The Evaluation Of Silicon Nitride Thin Films, Weston T. Mangin

Master's Theses

Silicon nitride thin films are of interest in the biomedical engineering field due to their biocompatibility and favorable tribological properties. Evaluation and understanding of the properties of these films under diverse loading and failure conditions is a necessary prerequisite to their use in biomedical devices. Three wafers of silicon nitride-coated silicon were obtained from Lawrence Livermore National Laboratory and used to create 96 samples. Samples were subjected to nanoindentation testing to evaluate the mechanical properties of the film. Samples were subjected to nanoimpact testing to compare the damage resistance of the film to separate nanoimpact types. Samples were subjected to …

A 3-D Multiplex Paper-Microfluidic Platform, Mitchell Patrick Young

Master's Theses

3-D paper-based microfluidic devices (micoPADs) are small and portable devices made out of paper that offer a promising platform for diagnostic applications outside of a laboratory. These devices are easy to use, low cost, require no power source, and capable of detecting multiple targets simultaneously. The work in this thesis demonstrated the ability of a 3-D paper-microfluidic platform to simultaneously detect 5 targets. Rubber cord stock was used in conjunction with an acrylic housing unit to apply pressure along the edge of the channel. The indirect pressure application was successful in promoting vertical fluid flow between layers. Average channel development …

Three-Dimensional Adult Cardiac Extracellular Matrix Promotes Maturation Of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes, Ahsley H. Fong, Mónica Romero-López, Christopher M. Heylman, Mark Keating, David Tran, Agua Sobrino, Anh Q. Tran, Hiep H. Pham, Cristhian Fimbres, Paul D. Gershon, Elliot L. Botvinick, Steven C. George, Christopher C.W. Hughes

Biomedical Engineering

Pluripotent stem cell-derived cardiomyocytes (CMs) have great potential in the development of new therapies for cardiovascular disease. In particular, human induced pluripotent stem cells (iPSCs) may prove especially advantageous due to their pluripotency, their self-renewal potential, and their ability to create patient-specific cell lines. Unfortunately, pluripotent stem cell-derived CMs are immature, with characteristics more closely resembling fetal CMs than adult CMs, and this immaturity has limited their use in drug screening and cell-based therapies. Extracellular matrix (ECM) influences cellular behavior and maturation, as does the geometry of the environment—twodimensional (2D) versus three-dimensional (3D). We therefore tested the hypothesis that native …

Fluid Flow Characterization And In Silico Validation In A Rapid Prototyped Aortic Arch Model, Alexandra Mariel Knauer

Master's Theses

Transcatheter aortic heart valve replacement (TAVR) is a procedure to replace a failing aortic valve and is becoming the new standard of care for patients that are not candidates for open-heart surgery [2]. However, this minimally invasive technique has shown to cause ischemic brain lesions, or “silent infarcts”, in 90% of TAVR patients, which can increase the patient’s risk for stroke by two to four times in future years [3]. Claret Medical Inc., a medical device company, has developed a cerebral protection system that filters and captures embolic debris released during endovascular procedures, such as TAVR. This thesis utilized CT …

Functional Vasodilation And Vascular Reactivity In Arteriolar Collaterals In The Spinotrapezius Of Males And Females, Britta C. Nelson

Biomedical Engineering

Peripheral arterial occlusive disease (PAOD) occurs when there is narrowing or blockage of the peripheral arteries that carry blood to the extremities, most commonly the legs. The most common symptom of PAOD is intermittent claudication, or ischemic pain during exercise. Women with PAOD experience a greater extremity functional impairment than men. Since impaired vasodilation might cause the ischemic pain from PAOD, we should evaluate vasodilation post ligation in males and females in collateral vessels, which connect two arterial segments to maintain blood flow to an otherwise hypoxic area. First, we need to examine collateral vasodilation in unoperated male and female …

Improvement Of Mounting Techniques For Accelerated Wear Testing Of Artificial Heart Valves, Kyle Koon, Clay Bougher, Lawrence Yang

Mechanical Engineering

Confidential

Modification Of Offset Hip Impactor, Anton Gebert, Michael Rumery, Mark Sidor

Mechanical Engineering

More than 300,000 total hip replacement surgeries are performed in the US each year. Minimally invasive total hip replacement surgery requires modified tools to access the smaller incision. An offset hip impactor was redesigned to improve tool lifetime, ease of use, and manufacturing cost. The redesigned tool had an increased lifetime and a significant reduction in the number of parts. The report contains detail drawings, a manufacturing plan, and physical testing results.

Prosthetic Socket Cooling System, Benjamin K. Kraw, Kathy Ha, Derek Piastrelli, Cuong Lai

Mechanical Engineering

A team of four senior-level undergraduate students in the Interdisciplinary Senior Project Design course in the Engineering Department of California Polytechnic State University: San Luis Obispo have worked to develop a prosthetic socket cooling system, namely for veteran Taylor Morris and exclusively for a transfemoral prosthetic socket, under the Quality of Life+ Laboratory. This cooling system will utilize the thermoelectric effect known as the Peltier effect to transmit heat generated from the residual limb to the surrounding environment by means of forced convection over small aluminum heat sinks. Two measurement devices have also been developed to, one, measure the heat …