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Finite Element Analysis Of The Bearing Component Of Total Ankle Replacement Implants During The Stance Phase Of The Gait Cycle, S J. Hazelwood, Mohammad N. Noori, Naudereh B. Noori, Timothy S. Jain, Amanda Anderson, Joseph Rencis

Biomedical Engineering

Total ankle arthroplasty (TAA) is a motion-preserving treatment for end-stage ankle arthritis. An effective tool for analyzing these implants’ mechanical performance and longevity in silico is finite element analysis (FEA). An FEA in ABAQUS was used to statically analyze the mechanical behavior of the ultra-high-molecular-weight polyethylene (UHMWPE) bearing component at varying dorsiflexion/plantarflexion ankle angles and axial loading conditions during the stance phase of the gait cycle for a single cycle. The von Mises stress and contact pressure were examined on the articulating surface of the bearing component in two newly installed fixed-bearing TAA implants (Wright Medical INBONE II and Exactech …

A Study On The Effects Of Cementless Total Knee Arthroplasty Implants’ Surface Morphology Via Finite Element Analysis, Scott Hazelwood, Peter J. Hunt, Mohammad Noori, Naudereh B. Noori, Wael A. Altabey

Biomedical Engineering

Total knee arthroplasty (TKA) is one of the most commonly performed orthopedic surgeries, with nearly one million performed in 2020 in the United States alone. Changing patient demographics, predominately indicated by increases in younger, more active, and more obese patients undergoing TKA, poses a challenge to orthopedic surgeons as these factors present a greater risk of long-term complications. Historically, cemented TKA has been the gold standard for fixation, but long-term aseptic loosening continues to be a risk for cemented implants. Cementless TKA, which relies on the surface morphology of a porous coating for biologic fixation of implant to bone, may …

Thermal Preconditioning Effects On Perforation Propensity Of Transvenous Implantable Cardiac Leads Used For Pacing And Defibrillation, Diane Muff

Master's Theses

Thermal preconditioning to simulate shipping, handling and storage conditions did not affect distal tip stiffness values for permanently implantable cardiac leads used for pacing and defibrillation. Leads that were subjected to extreme temperatures and temperature cycling did not show changes in buckle force values compared with control specimens which were maintained at ambient room conditions. Absolute differences between all measurements were small, generally under 0.05 N and were attributable to measurement variability.

Buckle force values are used to assess the propensity of leads to perforate the heart, a rare but potentially serious complication of implantable pacing and defibrillation systems. Since …

2-Channel Eeg Neurofeedback System, Tim Erwin, Donna Nikjou, Sebastian Turkewitz

Electrical Engineering

This work describes the design of an EEG-based neurofeedback system which provides users with real-time feedback on their level of focus or relaxation. By analyzing the spectral content of the brain activity measured via scalp electrodes, focus and relaxation levels can be quantified. Based on these measurements, live feedback in the form of moving bar graphs is provided to users, allowing them to gain awareness of their mental-state and more efficiently learn how to consciously relax or focus. This project covers the design of the system, including amplification and filtering stages, digitization, and signal processing. The system interfaces with a …

Engineering An Injectable Hydrogel With Self-Assembling 3d Vasculature, Kendyl Cohn

Master's Theses

This research developed methods for culturing self-assembling capillaries in an injectable gel as a potential method for vascularizing tissue-on-a-chip models to mimic physiological drug delivery. Additionally, a mathematical model was developed as a tool for understanding nutrient delivery and comparison of potential delivery systems. Organs-on-a-chip provide novel platforms for studying biology and physiology in 3D, allow exploration of tissue engineering on a manageable scale, and serve as models for drug screening and drug-delivery testing.

Methods were first developed for co-culture of endothelial cells and fibroblasts (3T3s or HDFs) in 2D, evaluating culture time, seeding density and ratio of HUVECs and …

Development Of An Advanced Step Counting Algorithm With Integrated Activity Detection For Free Living Environments, Paige M. Dolan

Master's Theses

Physical activity plays a crucial role in maintaining overall health and reducing the risk of various chronic diseases. Step counting has emerged as a popular method for assessing physical activity levels, given its simplicity and ease of use. However, accurately measuring step counts in free-living environments presents significant challenges, with most activity trackers exhibiting a percent error above 20%. This study aims to address these challenges by creating a machine learning algorithm that leverages activity labels to improve step count accuracy in real-world conditions. Two approaches to balancing data were used: one employed a simpler oversampling technique, while the other …

Accessible Real-Time Eye-Gaze Tracking For Neurocognitive Health Assessments, A Multimodal Web-Based Approach, Daniel C. Tisdale

Master's Theses

We introduce a novel integration of real-time, predictive eye-gaze tracking models into a multimodal dialogue system tailored for remote health assessments. This system is designed to be highly accessible requiring only a conventional webcam for video input along with minimal cursor interaction and utilizes engaging gaze-based tasks that can be performed directly in a web browser. We have crafted dynamic subsystems that capture high-quality data efficiently and maintain quality through instances of user attrition and incomplete calls. Additionally, these subsystems are designed with the foresight to allow for future re-analysis using improved predictive models, as well as enable the creation …

Prosthetic Forearm Controller, Claire Tylutki, Kevin Lopatka, Sofia Zaletel, Hardit Singh

Electrical Engineering

The EMG controlled prosthetic arm project represents a significant advancement in upper limb prosthetics, leveraging cutting-edge technology to address critical user needs. With over two million individuals in the United States living with limb loss, a substantial portion being upper limb amputees, the demand for accessible and functional prosthetic solutions is pressing. This project focuses largely on refining prosthetic limb control through the integration of electromyography (EMG) signal processing and control. Using surface electrodes, this project employs non-invasive means of data collection combined with modern digital signal processing methods to implement faster and more accurate control. The control system also …

Manufacturing Silicone In-House For The Creation Of Customized Neurovascular Blood Vessel Mimics, Jacob Wilbert Perisho

Master's Theses

The Tissue Engineering Lab at California Polytechnic State University San Luis Obispo focuses on creating tissue-engineered Blood Vessel Mimics (BVMs) designed for the preclinical testing of neurovascular devices. These BVMs are composed of silicone models, representing anatomically accurate neurovasculatures, that are sodded with vascular cell types and then cultivated in bioreactors (which maintain physiologic conditions). These silicone models are currently sourced externally from industry partners, so the primary goal of this thesis was to develop the means and methods for the Tissue Engineering Lab to manufacture silicone models in-house.

The first aim of this thesis was to develop and explore …

Neonatal Respiratory Therapy Interface, Kennedy Austin, Evan Manley, Parker Murray, Harrison Oen

Biomedical Engineering

This Final Report reviews and outlines the scope, objectives, and deliverables for the BCPAP Interface Redesign project, aimed at enhancing the functionality, usability, and patient experience of the existing BCPAP interface. It also includes detailed testing results and manufacturing plans for the device prototype. The current system has challenges in universal usability, time constraints, and patient comfort, which this project intends to address effectively. The goal of this project is to reevaluate and redesign the interface of the bubble continuous positive air pressure (BCPAP) machine’s attachment site with the infant. Due to the millions of premature neonates and thousands of …

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 …

Assisted Delivery Device, Rachel Rowe, Madeliene Mumford, Jenna Eissmann, Brittany Trinh

Biomedical Engineering

Current devices used to assist in complicated births present serious risks to both the mother and the fetus, which has caused a decline in the use of these devices over the last decade. This senior project team has proposed an alternative device that interfaces with the infant’s shoulders that would decrease these risks and contribute to the decrease of unnecessary c-sections due to device inadequacy. This Statement of Work includes research on the downfalls of current devices, existing patents, customer requirements, engineering specifications, and a design plan through December of this year. The next phase of this project will include …

Auto Adjustable Flow Regulator, Ethan Hemmerlin, Jack Dooley

Biomedical Engineering

The Auto-Adjustable Oxygen Flowmeter device is to be used in conjunction with an oxygen source or reservoir, as well as a low-flow nasal cannula apparatus. The device is applicable for patients requiring an oxygen flow rate of 0-6 L/min. Further, the device works to maintain a healthy blood-oxygen concentration of 90-94% for typical patients, as well as an 88-92% range for COPD patients who are chronic CO2 retainers. A reflective pulse oximeter will record the SpO2 concentration of the patient. The outputted SpO2 concentration will be transmitted to an internal processing PCB from which it will interact with the oxygen …

Tourniquet Pressure Gradient Measurement Apparatus, Luis Enrique Perez, Elsa Elizabeth Bates

Biomedical Engineering

The goal of this project was to design a device that would measure pressure gradient data across the width of an elastic and inelastic tourniquet cuff using a human limb model. The main customer requirements that were focused on were to accurately measure the pressure from a tourniquet, keep the cost down, and be easy to use. The targeted design specifications were to read pressure values ranging from 0-400 mmHg, keep the test length under 5 minutes, and to keep the cost of materials under $400. The design of the device ended up consisting of 5 IV pouches that were …

Finite Element Analysis Of The Bearing Component Of Total Ankle Replacement Implants During The Stance Phase Of Gait, Timothy S. Jain

Master's Theses

Total ankle replacement (TAR) implants are an effective option to restore the range of motion of the ankle joint for arthritic patients. An effective tool for analyzing these implants’ mechanical performance and longevity in-silico is finite element analysis (FEA). ABAQUS FEA was used to statically analyze the von Mises stress and contact pressure on the articulating surface of the bearing component in two newly installed fixed-bearing total ankle replacement implants (the Wright Medical INBONE II and the Exactech Vantage). This bearing component rotates on the talar component to induce primary ankle joint motion of plantarflexion and dorsiflexion. The stress response …

Evaluation Of Polyvinyl Alcohol (Pva) For Electrospinning Utility In The Blood Vessel Mimic (Bvm) Lab, Logan Vandenbroucke

Master's Theses

Electrospinning has provided the opportunity to create extracellular matrix (ECM) mimicking scaffolds for the development of tissue-engineered constructs. Within Professor Kristen Cardinal’s Blood Vessel Mimic (BVM) Lab, at Cal Poly, there exists a constant demand for innovation and the expansion of polymer types and electrospinning capabilities for its BVM model. Along these lines, the BVM Lab has recently acquired two new electrospinning systems: the Spinbox, a commercially graded electrospinning system, and the Learn-By-Doing system, which was part of a recently completed thesis conducted by Jason Provol. Additionally, recently published literature has demonstrated polyvinyl alcohol (PVA) as a viable option for …

Using Noninvasive Calibrated Cuff Plethysmography To Observe The Effects Of Cold-Water Immersion On Arterial Compliance, Rita M. Grigorian

Biomedical Engineering: Graduate Reports and Projects

As the prevalence of cardiovascular diseases continues to exponentially grow in populations across the globe, the necessity of determining underlying factors, effective methods of diagnoses, and universally available preventive measures also grows. Early detection of endothelial dysfunction, a proven precursor of cardiovascular diseases, can be extremely impactful in encouraging preventative measures and early intervention before medical conditions become chronic. In recent years, ice plunging, a form of cryotherapy involving full body immersion in cold water, has gained popularity within circles of fitness and health practitioners, gaining the interest of people of all backgrounds. Certain parallels observed between the human physiological …

Effects Of Beet Supplements On Cardiovascular Response Using A Noninvasive Blood Pressure Cuff, Nicholas M. Hughes

Master's Theses

A Calibrated Cuff Plethysmography device was built, tested for verification, and used to experiment on human subjects to measure the cardiovascular response of consuming a beet supplement, specifically looking at arterial compliance and pressure-area curves. Each subject was tested four times. A baseline was measured under normal conditions and after five-minute hyperemia conditions. 10 subjects were given 6 ounces of water mixed with either purple Kool-Aid (control), a SuperBeets supplement, or a SuperBeets Sport supplement and after 45 minutes, measurements were taken undergoing normal and hyperemia conditions once more. The verification testing demonstrated the calibration of the device was effectively …

Development Of An Angiogenic Tissue-On-A-Chip Microenvironment, Eric Stuehr

Master's Theses

Preclinical testing is necessary to investigate the safety and efficacy of novel therapeutics before moving to clinical trials, yet approximately 90% of these therapies fail once tested in humans. This has led to increased interest in developing robust preclinical models that accurately mimic the complex human in vivo physiology. Microfluidic devices that can introduce dynamic conditions to 3D cell/organoid cultures, also known as tissue-on-a-chip, have emerged as physiologically relevant in vitro preclinical models that can achieve high throughput screening of therapeutics. The research presented here aimed to develop an angiogenic environment within a novel microfluidic device to stimulate formation of …

Novel Method Of The Quantification Of Turbulent Fluid Flow In Silicone Artery Phantoms Using Acoustic Analysis, Julia Wong

Master's Theses

Cardiovascular disease is the leading cause of death globally and is responsible for taking 17.9 million lives per year. Despite the use of clinical treatments and detection methods, there remains a large population of individuals that suffer from CVD whose symptoms are left undetected and untreated prior to a life-threatening cardiac event. This highlights a need for an early detection method that can prevent the manifestation and worsening of the disease as well as address limitations of current early detection methods. An area of interest for early detection of CVD is subclinical atherosclerosis, which is the long, early, asymptomatic stage …

Using Noninvasive Calibrated Cuff Plethysmography To Observe The Effects Of Cold-Water Immersion On Arterial Compliance, Rita M. Grigorian

Master's Theses

As the prevalence of cardiovascular diseases continues to exponentially grow in populations across the globe, the necessity of determining underlying factors, effective methods of diagnoses, and universally available preventive measures also grows. Early detection of endothelial dysfunction, a proven precursor of cardiovascular diseases, can be extremely impactful in encouraging preventative measures and early intervention before medical conditions become chronic. In recent years, ice plunging, a form of cryotherapy involving full body immersion in cold water, has gained popularity within circles of fitness and health practitioners, gaining the interest of people of all backgrounds. Certain parallels observed between the human physiological …

Time-Lapse Imaging Of Colorectal Cancer Tumors, Jasmeet Sandhu

College of Engineering Summer Undergraduate Research Program

This project was aimed to test and validate a newly constructed live-cell imaging system that allows for imaging and live cells and tissues. This system is comprised of an incubation chamber that controls that temperature and pH of live cell culture while on a microscope.

Upper Limb Tensegrity Exoskeleton, Emily Mendyke, Sha'anan Levy, Alan Zhang

College of Engineering Summer Undergraduate Research Program

Tensegrity structures are composed of stiff rods and elastic cables suspended in a flexible tension network. Their inherent properties have several key advantages when used in assistive medical devices such as supportive braces or rehabilitation exoskeletons: 1) the lightweight and natural compliance reduces the power consumption required to operate the system; 2) the system stiffness and pretension can be individually tuned to accommodate the user’s needs; and 3) the impact-resistant properties can protect users in the event of collisions and falls. This project explores the design space of assistive tensegrity devices to augment human dexterity in the upper limb. Suitable …

Subject-Specific Human Knee Fea Models For Transtibial Amputees Vs Control Tibial Cartilage Pressure In Gait, Cycling And Elliptical Training, Ali Yazdkhasti

Master's Theses

Millions of individuals around the globe are impacted by osteoarthritis, which is the prevailing type of arthritis. This condition arises as a result of gradual deterioration of the protective cartilage that safeguards the ends of the bones. This is especially true of transtibial amputees, who have a significantly higher incidence of osteoarthritis of the knee in their intact limb than non-amputees. Engaging in regular physical activity, managing weight effectively, and undergoing specific treatments can potentially slow down the advancement of the disease and enhance pain relief and joint function. Nevertheless, the relationship between the type of exercise and its impact …

Static Vascular Modeling Of Diabetes Progression, Andrea Skattenborg

Master's Theses

Cardiovascular disease is the leading cause of mortality in diabetic patients, and diabetes is one of the main causes of cardiovascular disease. Risk factors for cardiovascular disease result in structural and functional changes in the vascular wall. Arterial stiffness is a prominent structural change observed in the arterial wall that can be measured in clinical settings. The purpose of this thesis was to create a static model of the changes in arterial stiffness seen in diabetes. Elastic tubes with varying wall thicknesses were used to create artificial arteries for this purpose. Compliance (inverse of stiffness) of the arteries was determined …

Bruxism Biofeedback Device, Claire A. Dossey, Errin S. Abasolo, Isabelle A. Starr

General Engineering

This paper aims to summarize the design process for a biofeedback bruxism device, covering the necessary background research, engineering requirements, design process, prototyping, manufacturing, and testing for the device. The purpose of this project was to design an engineering solution for the treatment of bruxism. This entails both measuring and significantly reducing clenching and grinding during sleep, as many current solutions may reduce symptoms of the disorder, but do not treat bruxism itself. Engineering requirements included biocompatibility, size and weight, electrical safety, and easy of use and comfort. Many design options were proposed, and a Pugh Matrix was used to …

Analysis Of Arterial Compliance Using A Surrogate Arm Bench Top Model For The Validation Of Oscillometric Blood Pressure Methods, Christopher J. Cunningham

Master's Theses

A study was performed on a recently developed prototype of the Yong-Geddes surrogate arm design to collect compliance data of the various system components and determine the accuracy of measurements made through the bench top model. The study was performed to perceive the effectiveness of the model as a tool for validating non-invasive blood pressure detection monitors. Three stages of testing were performed to gather pressure and volume data from an artificial artery component, a sphygmomanometer, and the surrogate arm system to produce compliance estimations. Mathematical equations from supported arterial hemodynamics studies and clinical trials were applied to the pressure …

Design And Validation Of A Wearable Smartsole For Continuous Detection Of Abnormal Gait, Karoline M. Wucherer

Master's Theses

Residual gait abnormalities are common following lower limb injury and/or stroke and can have several negative impacts on an individual’s life. Without continuous treatment and follow up, individuals can be prone to chronic pain as abnormal gait may lead to non-physiological loading of the musculoskeletal system. The current industry gold standard for diagnosing abnormal gait requires specialty equipment that is generally only available at designated gait facilities. Due to the inaccessibility and high cost associated with these facilities, a wearable SmartSole device to continuously detect abnormal gait was proposed. A previous iteration of the SmartSole was unable to properly detect …

Biomechanical Knee Joint For Exoskeleton, Gabriel Ireton Ahern, Calloway Miller, Christianna Altamura, Eric Mailes

Mechanical Engineering

Our senior design project consisted of designing and manufacturing a biomechanically accurate, actuated knee joint to be integrated into an exoskeleton being developed by the Lower Limb Exoskeleton Assist Project (LLEAP), a part of the EMPOWER student association at Cal Poly, San Luis Obispo. As the human knee flexes and extends throughout gait motion, the center of rotation changes. Currently marketed exoskeletons have one point of rotation, which over constrains the knee and causes misalignment between the user and the suit [1]. Our goal was to mimic natural knee joint motion by changing the center or rotation, thus reducing misalignment …