Biomedical Engineering and Bioengineering Commons^™

Improving Patient-Specific Assessments Of Regional Aortic Mechanics Via Quantitative Magnetic Resonance Imaging With Early Applications In Patients At Elevated Risk For Thoracic Aortopathy, Patrick A. Jones

Theses and Dissertations

Unstable aortic aneurysms and dissections are serious cardiovascular conditions associated with high mortality. The current gold standards for assessment of stability, however, rely on simple geometric measurements, like cross-sectional area or increased diameter between follow-up scans, and fail to incorporate information about underlying aortic mechanics. Displacement encoding with stimulated echoes (DENSE) magnetic resonance imaging (MRI) has been used previously to determine heterogeneous circumferential strain patterns in the aortas of healthy volunteers. Here, I introduce technical improvements to DENSE aortic analysis and early pilot application in patients at higher risk for the development of aortopathies. Modifications to the DENSE aortic postprocessing …

Evaluating Neuromuscular Function Of The Biceps Brachii After Spinal Cord Injury: Assessment Of Voluntary Activation And Motor Evoked Potential Input-Output Curves Using Transcranial Magnetic Stimulation, Thibault Roumengous

Theses and Dissertations

Activation of upper limb muscles is important for independent living after cervical spinal cord injury (SCI) that results in tetraplegia. An emerging, non-invasive approach to address post-SCI muscle weakness is modulation of the nervous system. A long-term goal is to develop neuromodulation techniques to reinnervate (i.e. resupply nerve to) muscle fiber and thereby increase muscle function in individuals with tetraplegia. Towards this goal, developing monitoring techniques to quantify neuromuscular function is needed to better direct neurorehabilitation. Assessment of voluntary activation (VA) is a promising approach because the location of the stimulus can be applied cortically using transcranial magnetic stimulation (TMS) …

Applied Machine Learning In Extrusion-Based Bioprinting, Shuyu Tian

Theses and Dissertations

Optimization of extrusion-based bioprinting (EBB) parameters have been systematically conducted through experimentation. However, the process is time and resource-intensive and not easily translatable across different laboratories. A machine learning (ML) approach to EBB parameter optimization can accelerate this process for laboratories across the field through training using data collected from published literature. In this work, regression-based and classification-based ML models were investigated for their abilities to predict printing outcomes of cell viability and filament diameter for cell-containing alginate and gelatin composite hydrogels. Regression-based models were investigated for their ability to predict suitable extrusion pressure given desired cell viability when keeping …

Nebulizer-Based Systems To Improve Pharmaceutical Aerosol Delivery To The Lungs, Benjamin M. Spence

Theses and Dissertations

Combining vibrating mesh nebulizers with additional new technologies leads to substantial improvements in pharmaceutical aerosol delivery to the lungs across therapeutic administration methods. In this dissertation, streamlined components, aerosol administration synchronization, and/or Excipient Enhanced Growth (EEG) technologies were utilized to develop and test several novel devices and aerosol delivery systems. The first focus of this work was to improve the poor delivery efficiency, e.g., 3.6% of nominal dose (Dugernier et al. 2017), of aerosolized medication administration to adult human subjects concurrent with high flow nasal cannula (HFNC) therapy, a form of continuous-flow non-invasive ventilation (NIV). The developed Low-Volume Mixer-Heater (LVMH) …

Biocybersecurity: A Converging Threat As An Auxiliary To War, Lucas Potter, Orlando Ayala, Xavier-Lewis Palmer

Engineering Technology Faculty Publications

Biodefense is the discipline of ensuring biosecurity with respect to select groups of organisms and limiting their spread. This field has increasingly been challenged by novel threats from nature that have been weaponized such as SARS, Anthrax, and similar pathogens, but has emerged victorious through collaboration of national and world health groups. However, it may come under additional stress in the 21st century as the field intersects with the cyberworld-- a world where governments have already been struggling to keep up with cyber attacks from small to state-level actors as cyberthreats have been relied on to level the playing field …

Osteocyte Activity And Skeletal Muscle Relative Gene Expression Profiling After Short-Term Muscle Paralysis, Michelle Gelbs

Dissertations and Theses

Mechanical loading is essential for maintaining bone tissue. Reduced mechanical loading has been shown to have a negative effect on bone, and can result in the development of disuse osteoporosis. Disuse models of muscle inactivity and immobilization, like the Botox model used in this study, result in changes in the bone microarchitecture, the mechanisms behind which are not fully understood. In a previous four-week Botox disuse study, skeletally mature 20- week-old rats experienced degradation of intracortical bone, increased vascular porosity, and decreased osteocyte lacunar density in the tibiae. The focus of this study was to explicate a potential source of …

Development Of An Injectable Methylcellulose Hydrogel System For Nucleus Pulposus Repair And Regeneration, Nada A. Haq-Siddiqi

Dissertations and Theses

Low back pain is the most common cause of disability in the world and is often caused by degeneration or injury of the intervertebral disc (IVD). The IVD is a complex, fibrocartilaginous tissue that allows for the wide range of spinal mobility. Disc degeneration is a progressive condition believed to begin in the central, gelatinous nucleus pulposus (NP) region of the tissue, for which there are few preventative therapies. Current therapeutic strategies include pain management and exercise, or surgical intervention such as spinal fusion, none of which address the underlying cause of degeneration. With an increasingly aging population, the socioeconomic …

Development Of A Biaxial Testing System For Research Of Soft Tissue Biomechanics Using Laboratory Models, Tariq Shameen

Dissertations and Theses

The rupture of the cap tissue layer of a fibroatheroma in human coronary vessels is considered the key event leading to the formation of a thrombus and myocardial infarction, resulting in more than half a million deaths in the US every year. In this study, we are interested in investigating the biomechanics of different elastomer materials that can be used as laboratory models to replicate coronary arteries’ ultimate tensile stress (0.2 - 2.08 MPa). To this end, we developed a biomechanical testing system that allows us to characterize the material properties of small samples with high accuracy and precision. We …

Optimization Of Gelatin-Based Cellular Coating Of Msc For Myocardial Infarction Therapy, Kara Amelle Davis

Theses and Dissertations--Chemical and Materials Engineering

Cardiovascular disease remains the number one threat to American lives. During an acute myocardial infarction (AMI), blood flow is blocked and results in the formation of scar tissue. As the body’s immune system responds, inflammatory signaling causes an increase in both scar tissue size and the patient’s risk for further chronic heart failure. In order to reduce the risk of continued heart disease inflammatory signaling must be reduced. Stem cell therapies have the ability to alter the immune system’s pro-inflammatory signal. However, stem cell retention is limited due to blood flow shear. Gelatin methacrylate (GelMA) based coatings have been shown …

Biom 3710: Physiological Systems And Modeling (Syllabus), Aaryani Sajja

Biomedical Engineering Syllabi Archive

Course Description: Fundamentals of control theory and mathematical modeling and analysis as applied to physiological systems.

Engr 1010: Engineering Problem Solving (Syllabus), Stephen Strain

Biomedical Engineering Syllabi Archive

Course Description: Introduction to the methods of engineering problem solving. Application of mathematical concepts to solve engineering problems.

การเปรียบเทียบวิธีประเมินการจำแนกเสียงพูดโดยใช้ศักย์ไฟฟ้าสมองสัมพันธ์กับเหตุการณ์, พิมพ์วิภา จารุธำรง

Chulalongkorn University Theses and Dissertations (Chula ETD)

การจำแนกเสียงพูดคือความสามารถในการจำแนกระหว่างเสียงพยางค์หรือคำ คนที่มีความสามารถในการจำแนกเสียงพูดต่ำมักจะมีปัญหาในการแยกระหว่างคำที่มีเสียงคล้ายกัน โดยปกติการจำแนกเสียงพูดถูกประเมินโดยนักโสตสัมผัสวิทยาทำให้เข้าถึงการประเมินได้ยากเนื่องจากมีนักโสตสัมผัสวิทยาจำนวนไม่มาก นอกจากนี้การประเมินอาจใช้เวลานานหรือไม่สะดวกสำหรับผู้ป่วยบางกลุ่ม เพื่อลดปัญหาเหล่านี้จึงมีการพัฒนาวิธีประเมินการจำแนกเสียงพูดโดยใช้ศักย์ไฟฟ้าสมองสัมพันธ์กับเหตุการณ์ (Event-Related Potentials) วิธีหนึ่งที่มีการใช้คือการสังเกตองค์ประกอบ Mismatch Negativity (MMN) ระหว่างทำการทดลองการฟังแบบ Oddball ต่อมามีการเสนอวิธีใหม่โดยนำสิ่งกระตุ้นทางสายตาที่เป็นตัวอักษรมาใช้ร่วมกับสิ่งกระตุ้นทางเสียง งานวิจัยนี้เสนอวิธีการประเมินโดยใช้ภาพที่แสดงถึงความหมายของคำโดยแบ่งออกเป็นสามแบบที่มีจำนวนภาพและลำดับในการทดลองแตกต่างกัน วิธีใช้ภาพความหมายของคำแต่ละแบบรวมทั้งวิธีที่ใช้การฟังแบบ Oddball และวิธีที่ใช้ตัวอักษรถูกนำมาทดสอบโดยใช้คำสองคำที่มีเสียงพยัญชนะต่างกันแต่มีเสียงสระและเสียงวรรณยุกต์เหมือนกันเพื่อเปรียบเทียบระหว่างแต่ละวิธีโดยนำรูปคลื่นที่ได้มาสร้างเป็นชุดคุณลักษณะแล้วใช้เทคนิคการเรียนรู้ของเครื่อง (Machine Learning) เพื่อจำแนกระหว่างแต่ละเงื่อนไขในการทดลองซึ่งตัวจำแนกที่ใช้ได้แก่ Linear Discriminant Analysis (LDA) และ Support Vector Machine (SVM) จากการเปรียบเทียบพบว่ามีวิธีที่สามารถนำมาใช้สองวิธี ได้แก่วิธีใช้ภาพความหมายของคำแบบภาพเดียวและวิธีไม่ใช้ภาพ ทั้งสองวิธีนี้ให้ความแม่นยำในการจำแนกสูงกว่า 80% และใช้เวลาหรือสมาธิในการทดลองน้อยกว่าวิธีอื่น การประเมินการจำแนกเสียงพูดโดยใช้วิธีเหล่านี้สามารถนำไปใช้เป็นเครื่องมือคัดกรองอัตโนมัติที่ช่วยประเมินและแนะนำว่าผู้ป่วยควรจะถูกส่งต่อเพื่อตรวจยืนยันกับนักโสตสัมผัสวิทยาหรือไม่ซึ่งสามารถช่วยลดภาระงานของนักโสตสัมผัสวิทยาและทำให้การประเมินเข้าถึงได้ง่ายขึ้น

Barcode Biosensors Based On Surface Plasmon Resonance, Sneha Ramesh

Graduate Research Theses & Dissertations

Affordable and easy to use biological assays are the current need of the day owing to the rising cost of health care within the US and worldwide. The goal of this thesis is to develop a sensitive label-free biosensing scheme exploiting surface plasmon resonance (SPR) that yields the sensor output in an easy-to-read optical bio-barcode format for high through put and multiplexed medical diagnostics. Through this research, we would like to investigate if SPR phenomena can be achieved by fabricating SP supporting metallic structures over a nanoporous dielectric layer whose optical constants are progressively varied across the substrate in a …

Clinical Applications And Feasibility Of Proton Ct And Proton Radiography, Christina Marie Sarosiek

Graduate Research Theses & Dissertations

Proton therapy is a form of radiation treatment for cancer that utilizes the Bragg peak to create conformal high dose regions around the tumor volume. However, the use of x-ray computed tomography (CT) and x-ray radiography for treatment planning and pre-treatment quality assurance procedures improves the achievable effectiveness of proton treatment plans (using proton CT) and the pretreatment verification (using proton radiography). Errors in the conversion from x-ray Hounsfield units (HU) to proton relative stopping powers (RSP) leads to errors in the predicted proton range. To account for the errors, 3.5% margins are included in the treatment plan. This means …

Photodynamic Therapy Of Inorganic Complexes For The Treatment Of Cancer, Chloe B. Smith, Lindsay C. Days, Duaa R. Alajroush, Khadija Faye, Yara Khodour, Stephen J. Beebe, Alvin Holder

Chemistry & Biochemistry Faculty Publications

Photodynamic therapy (PDT) is a medicinal tool that uses a photosensitiser and a light source to treat several conditions, including cancer. PDT uses reactive oxygen species (ROS) such as cytotoxic singlet oxygen ¹O₂ to induce cell death in cancer cells. Chemotherapy has historically utilized the cytotoxic effects of many metals, especially transition-metal complexes. However, chemotherapy is a systemic treatment so all cells in a patient's body are exposed to the same cytotoxic effects. Transition metal complexes have also shown high cytotoxicity as PDT agents. PDT is a potential localized method for treating several cancer types by using inorganic …

Neurovascular Catheter Measurement System Development For Process And Design Effect Evaluation, Cathal Tadhg Merz

Theses

Neurovascular guide catheters are used to treat problems affecting blood vessels within the brain through minimally invasive procedures. Catheters are inserted into the patient via their femoral or brachial arteries and manually navigated to the brain to deliver treatment. This procedure replaces the requirement to cut into the patient’s skull and brain tissue but is limited by reduction of blood vessel lumen diameter and increase in tortuosity of blood vessels deep in the brain. During these procedures, catheters can sometimes fail by kinking or fracturing into two pieces. The rate of failure by fracture of a particular neurovascular catheter device …

Lateralized Laryngoscope Blade, Kenneth Gregg, Steven Innocenzi, Jacob Myers, Regina Neugebauer, Clarence Noronha

Williams Honors College, Honors Research Projects

Tracheal intubations are one of the most common surgeries that occur since they are necessary for most patients under anesthesia. Given the frequency, an error with a relatively low chance of occurring can still provide a large problem both for the patient and the hospital. We studied teeth damage that arise during tracheal intubations to determine if improvements could be made to the process to lower the chance of it occurring. Given this, we set out to improve the laryngoscope to provide a product with a novel approach that sweeps into the mouth from the left side before traveling the …

Tubing/Lines Entanglement Reduction In Healthcare Settings, Abigail Kraft, Amy Beskitt, Grace Elerick, Zachery Steck

Williams Honors College, Honors Research Projects

Intravenous (IV) lines used in various healthcare settings pose a risk to patients and their caretakers. A few common risks include IV lines becoming torn out and coming into contact with open wounds. We propose to solve this problem by designing a device that prevents IV and wire entanglement without obstructing patient care. Our objectives in identifying a solution include increasing patient comfort, mobility, and ease of transfer. By solving this issue, other potential benefits include reducing time spent on non-essential tasks and reducing number of personnel needed to transport patients. We intend to validate our product with healthcare employees …

Rheological Analysis Of The Mechanical Properties Of Murine Lungs Over The Lifespan, Olajumoke Olufunke Harrison

Theses and Dissertations

To study the effects of aging in murine lungs, we characterized C57Bl6j mice from neonatal to 24-month-old mice. Samples were divided into two groups: Young Mice (YM) and Middle Age/Old Age Mice (MOM). The YM group included the neonatal and 6-10week. The MOM group included 7- and 22–24-month-old mice. Rheological testing was performed using a TA Instruments DHR-2 Rheometer to collect the mechanics of each mice sample. Utilizing a 20-mm parallel plate fixture, a gap of 0.8-1.0-mm, and a temperature setting of 25C, we conducted a frequency sweep. Samples were the decellularized over a four-day process then lyophilized for mass …

Therapeutic Modalities For Preventing Osteoarthritis Following Trauma To The Knee, Kayla M. Scott

Theses and Dissertations

Over 32.5 million adults in the United States and 300 million worldwide have osteoarthritis (OA). To date, there are no disease-modifying therapeutics, only strategies to slow OA progression through pain management, regenerative medicine approaches, and ultimately joint replacement.

On a microscale, a phenotypic shift of the normally quiescent articular chondrocytes leads to aberrant expression of pro-inflammatory and catabolic pathways, which are hypothesized to contribute to OA progression. Of note, interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and WNT/β-catenin signaling are key players disrupting cartilage homeostasis and driving inflammatory pathway activation. These pathways become dysregulated and form a positive feedback loop, increasing …