Biomedical Devices and Instrumentation Commons^™

Using Deep Learning And Two-Photon Excitation Fluorescence Microscopy To Predict Breast Cancer Recurrence And Response To Chemotherapy, Nicholas Powell

Graduate Theses and Dissertations

Accurate prediction of breast cancer recurrence plays a critical role in guiding treatment decisions, particularly regarding the use of systemic therapy for patients. While genomic assays such as the Oncotype DX Recurrence Score offer valuable prognostic information, they are limited in accessibility and application. The work presented in this thesis explores an imaging-based approach for the prediction of breast cancer recurrence that combines multiphoton microscopy (MPM) with deep learning to classify individual breast cancer biopsy samples by risk of recurrence. Genomic differences in tumors with different recurrence potentials may translate to distinct optical and structural information that can be captured …

Efficacy Of Mitophagy Inhibition As A Potentiating Agent For Conventional Chemotherapy, Morghan Relich, Shelby Bess

Biomedical Engineering Undergraduate Honors Theses

Cancer is a result of uncontrolled growth and reproduction of cells. Damaged or abnormal cells grow and multiply when they should not and in turn the cells continue to proliferate and metastasize. Malignant cells rely on functional mitochondria for proliferation, metastasis, and survival. These mitochondria maintain a functional mitochondrial network through a quality control mechanism called mitophagy. Mitophagy is a conserved intracellular process to maintain quality control and remove damaged mitochondria.

Previous research has been done to examine the effects of mitophagy in tumor cells, as well as the effects of mitophagy inhibition. One focus of current research has been …

Real-Time Measurements From Wearable Sensors To Enhance Stability On Uneven Terrain, Sophie Copelin

Biomedical Engineering Undergraduate Honors Theses

The presented thesis is a study of sensation associated with inversion/eversion movement about the anterior/posterior axis. The long-term goal is to create a system that provides feedback to a prosthesis user, so their chances of falling is decreased. This feedback system would use wearable sensors to detect certain angles, so that sensory feedback could be provided. The study aimed to determine if Xsens Movella DOT sensors could be used in a system like this, so the accuracy of the Xsens Movella DOT sensors was assessed and the difference in angles that could be determined by them when compared to that …

A Framework Of Flow Models For The Development And Testing Of Cardiovascular Devices, Megan Laughlin

Graduate Theses and Dissertations

Cardiovascular disease (CVD) is the leading cause of death worldwide and its treatment continues to improve due to the advancement of innovative cardiovascular medical devices. In vitro and in silico models serve to replicate the in vivo environment for the development and testing of these devices prior to using animals for testing, and eventually humans in clinical trials. However, limitations related to these models exist in multiple areas including general, cardiac, and venous applications. Specifically, current gaps have been identified with customizable, tissue-mimicking phantoms (general), 2D Blood Speckle Imaging (BSI) (cardiac) and a bioprosthetic venous valve (venous). This dissertation focuses …

Tissue-Engineered Models For Investigating Nerve Infiltration In Fibrotic Microenvironments, Nikolas Ala-Kokko

Graduate Theses and Dissertations

Neuron infiltration is involved in a multitude of diseased states and is critical in the regeneration of physiologic conditions. Modeling of innervation in three-dimensional, heterogenous, environments would allow early investigation in the crosstalk of neurons and native cells in normal and pathophysiologic microenvironments to gain an understanding of mechanistic functions. This would allow for greater insight into the role of metabolism, cell adhesion, microenvironmental alternations, cellular crosstalk, and signaling pathways that play a role in the promotion and prevention of neurite growth. In this thesis, with the construction of collagen-based hydrogels as the foundation for cell culture, we investigate cell …

A Wheelchair-Bed Transfer Device For Patients With Limited Mobility, Malachie Nichols

Biomedical Engineering Undergraduate Honors Theses

As the population ages, eldercare becomes more important than ever, yet many caregivers lack the resources they need to safely do their jobs. For those who take care of a disabled loved-one at home or work as home health aides, basic tasks can be frustrating and even dangerous. The high physical demands of moving and lifting patients make injuries common among home health care workers. Musculoskeletal injuries to the back, shoulders, wrists, and hands are especially common. The use of transfer devices such as Hoyer lifts, slide boards, and gait belts help to make moving patients easier and safer, but …

Characterizing And Quantifying Shear-Induced Hemolysis In A Hollow Fiber Membrane System, Siddhi Bhat

Chemical Engineering Undergraduate Honors Theses

Clinical studies have shown that patients undergoing renal replacement therapy are more susceptible to developing hemolysis, or the rupturing of red blood cells. Rapid hemolysis can cause symptoms such as anorexia, vomiting, and even death in severe cases. The aim of this study is to identify how shear stress within a hollow fiber membrane impacts the level of hemolysis that occurs. This allows for the optimization of the ultrafiltration membranes that are typically used for hemofiltration treatments. The variables being studied are the radii of hollow fibers, number of fibers, and volumetric flow rate of blood being circulated. Here, we …

Mitral Valve Imaging And Biomechanics: A Workflow Towards Computational Modeling And Validation, Sam Stephens

Graduate Theses and Dissertations

The mitral valve serves a critical role in healthy cardiac function by ensuring the unidirectional flow of oxygenated blood from the left atrium into the left ventricle. It experiences the highest pressures found within the heart and its closure is the result of a complex interaction of several different structures that, furthermore, are unique to each individual. Despite the valve’s vital role however, the specific function of these constituent structures is not fully understood. This, confounded by its asymmetric, personalized nature, make surgical interventions for the mitral valve far less effective than for its neighboring aortic valve. Efforts to overcome …

Ultrasound Mediated Tissue Growth In Bioinspired Scaffolds, Marco Fielder

Graduate Theses and Dissertations

Porous scaffolds mechanically stimulated with ultrasound are used for the treatment of bone conditions such as osteoporosis or traumatic bone injury. However, one current issue in these treatment techniques is designing a scaffold structure with a high structural integrity that also does not impede tissue growth. A larger ultrasound wave transmission would also allow more of a scaffold to receive mechanical stimulation from ultrasound. Controlling mesenchymal stem cell seeding of tissue scaffolds also has potential for developing optimal seeding patterns to maximize or control tissue growth in the scaffold based on an individual’s physiology. There is also a need for …

Engineer And Test A Biodegradable Microneedle Patch To Deliver Meloxicam For Managing Pain In Cattle, Katherine Alejandra Miranda Munoz

Graduate Theses and Dissertations

Microneedle patches are a promising source for transdermal diffusion of macromolecules and are designed to painlessly penetrate the skin. In this study, a biodegradable chitosan microneedle patch to deliver meloxicam for managing pain in cattle was tested. The potential of reuse of the polymeric solution to fabricate the patches, optimization of fabrication, morphological analysis of the microneedle patch and analysis of preservation of the chemical composition after sterilization were evaluated. In-vitro analysis consisted of studying in-vitro penetration mechanical properties, compression testing analysis of microneedle patch, and in-vitro drug release analysis. In-vivo studies were performed to analyze the dissolution capability of …

Evaluation Of Cellulose Nanocrystal Inks And Their Structural Characteristics For 3d Bioprinting Of Customized Scaffolds, Patrick William Kuczwara

Graduate Theses and Dissertations

3D bioprinting of biological scaffolds requires control of the physicochemical properties of each unique structures. A promising material for control of properties is hydrogels, which can help create biomimetic scaffolds with controlled spatial arrangement of materials by integrating biological materials directly into layers during the bioprinting process. Nanocellulose offers a unique combination of properties including mechanical, biomimetic, and biocompatibility. These properties offer flexibility over the types, shapes, and applications of their printed hydrogel scaffolds, (i.e., tissue, drug, encapsulation). However, 3D bioprinting of nanocellulose-based hydrogels requires high loading percentages (i.e., >10 wt%) or chemical crosslinkers (i.e., bis(acyl)phosphane oxides (BAPO)). High solid …

Restoring An Iso:5840-Compliant Pulse Duplicator Device For Hydrodynamic Performance Characterization Of Artificial Cardiac Valves, Denver Eagar

Biomedical Engineering Undergraduate Honors Theses

During the summer of 2021, I was employed as an intern at Dynatek Labs, an implantable prosthetics testing company located in southern Missouri. My primary project was to modernize an abandoned pulse duplicator device and protocol to allow the company to re-enter a market area which they left nearly 15 years prior: heart valve testing. The company halted this initiative due to changes in international testing standards in previous years. The International Standards Organization Cardiac Valves Working Group released the latest version of standards concerning artificial heart valve testing (ISO 5840) in January of 2021. Accordingly, my project required that …

Surface Laser Texturing Of Cocrmo Alloys, Gabriel Dharwadker

Biomedical Engineering Undergraduate Honors Theses

Artificial orthopedic implants such as hip joints suffer from excessive wear due to excess friction between the polyethylene and cobalt-chromium-molybdenum surfaces of the device. This increase in friction causes a fraction of them to give out within ten years. Therefore, to minimize the probability of this happening, recent research has been conducted regarding laser surface texturing of the cobalt-chromium-molybdenum alloy components of artificial joints. These surface textures serve to mimic the native lubrication mechanisms of cartilage in natural joints, which, in a natural joint, lowers the friction. However, the production of these laser surface textures is still a field of …

Sequential Illumination In A Tomographic Microendoscopic Probe For Imaging Tumor Microvasculature, Zachariah Neumeier

Biomedical Engineering Undergraduate Honors Theses

Knowledge of colorectal cancer biology is improving how we approach cancer treatment. Specifically, the tumor microenvironment and abnormal angiogenesis are of particular interest. Optical methods are a prime candidate for research of the tumor microenvironment due to their ability to quantitively assess tissue structure and perfusion in real time. Particularly, the “transport scattering regime” has been identified as a method of obtaining high-resolution images and reflectance spectroscopy data; this light scattering regime has been demonstrated compatible with endoscopic imaging systems. In this study, a proof-of-concept optical imaging system is presented, capable of resolving absorbers within scattering turbid media using a …

The Effects Of Microgravity On Human Endothelial Cells In Relation To Deep Vein Thrombosis, Allie Burgess

Biomedical Engineering Undergraduate Honors Theses

Deep vein thrombosis (DVT) is a condition where blood clots form in one or more of the deep veins of the body, causing leg pain and/or swelling, potentially leading to pulmonary embolism and/or stroke. The incidence of DVT among astronauts serving on the International Space Station has been shown to be greater than that of the general population, calling into question the effects of microgravity on human thrombolytic processes. Additionally, microgravity conditions have been shown to cause muscular atrophy and a decrease in muscle strength and mobility. Because collagen composes a large portion of muscle tissue, this study also assessed …

Modifications Of A Machine To Produce Clinically-Sized Angioplasty Balloons For Bifurcations, Natalie Smith

Biomedical Engineering Undergraduate Honors Theses

Coronary artery disease is the most common form of heart disease and the leading cause of death in the U.S. ("Heart Disease Facts | cdc.gov", 2021). Typically, coronary artery disease is a result of coronary stenosis, constriction of the coronary artery, which can cause heart failure, arrhythmia, or heart attack ("Coronary Artery Disease: Prevention, Treatment and Research", 2021). Angioplasty balloons are a common treatment method for coronary stenosis and work by placing a stent at the lesion site to widen the vessel and promote blood flow. A type of lesion which remains particularly difficult and relatively common to treat is …

3d Volumetric Mapping Of Tissue Properties Via A Catheter-Scale Microendoscope Imaging System, Andrew Stark

Biomedical Engineering Undergraduate Honors Theses

The study of tumor microvasculature is an important area of interest for research and clinical communities; however, there are significant limitations in the clinical characterization of the tumor microenvironment. Optical methods offer quantitative real-time measurement of tissue structure and perfusion and can be miniaturized for deployment endoscopically into previously inaccessible locations. However, conventional optical methods (i.e., optical coherence tomography, white light endoscopy, etc.) gives limited information about tissue perfusion while the diameter of various optical probes along with the complexity of scanning mechanisms make it difficult to access certain areas. In this study, a new technique for characterizing the tumor …

Clot Analogs For The Development Of Improved Treatment Methods In Ischemic Stroke, Charles A. Rieth

Biomedical Engineering Undergraduate Honors Theses

According to the CDC, nearly 800,000 individuals experience stroke each year in the United States [1]. Greater than 70% of strokes are of ischemic etiology and involve the occlusion of key arteries in the cardiovascular system [2]. Tissue plasminogen activator (IV-tPA) is the current gold standard for thrombolytic approaches [3]; however, this therapeutic is only effective between 3 and 4.5 hours from the patient’s last know well [4]. As a result, less than 5% of acute ischemic stroke patients receive IV-tPA. In order to increase the viability of AIS treatment as a whole, it is essential that thrombolytic techniques are …

Pulse Rate Variability Analysis During Hemorrhage In An Experimental Porcine Model, Gabbie Bonvillain, Lauren Crimmins, Md Abul Hayat, Adria Abella Villafranca, Sam Stephens, Hanna K. Jensen, Joseph A. Sanford, Jingxian Wu, Kevin W. Sexton, Morten Jensen

Biomedical Engineering Undergraduate Honors Theses

During the acute phase of hemorrhage, heart rate and peripheral resistance increases to maintain proper oxygen delivery to vital organs. This response is mediated by the autonomic nervous system. Heart rate variability (HRV) has become a widely utilized measure to determine the autonomic nervous system control over the heart. Recently, pulse rate variability (PRV) has been suggested to serve as a surrogate for HRV. This study evaluates the ability of PRV obtained from peripheral arterial pressure waveforms as a method for detecting hemorrhage. Time domain and frequency domain metrics were evaluated for 5-minute and 15-minute arterial pressure waveform signals prior …

Localized Intra-Arterial Drug Delivery Device For Stroke Treatment, Benjamin Yip

Biomedical Engineering Undergraduate Honors Theses

Strokes are one of the leading causes of death and long-term disability in the United States, and according to the Centers for Disease Control and Prevention more than 795,000 people experience a stroke every year. Around 87% of all strokes are ischemic strokes making it the most common form of stroke. While ischemic strokes are treatable, current devices and methods still result in high mortality rates and high risks of hemorrhaging after treatment. The aim of this study is to design and test a prototype of a novel device for the localized delivery of thrombolytics to treat ischemic strokes. The …

Development Of A Long-Read Sequencing Protocol To Assess The Precision And Efficacy Of Gene Editing For Duchenne Muscular Dystrophy, Landon Andrew Burcham

Graduate Theses and Dissertations

This work establishes a method for assessing on-target precision due to CRISPR-Cas9 gene editing, especially within the context of exon skipping therapy for Duchenne Muscular Dystrophy. The proposed method utilizes an Oxford nanopore long-read sequencing approach to sequence amplified regions of DNA that have been edited using CRISPR-Cas9. NIH3T3 and C2C12 cell lines were treated with a dual-guide CRISPR-Cas9 system, that targets and deletes exon 23 from the DMD gene in mouse samples. Deletion PCR revealed deletion of exon 23 in both DNA and cDNA samples. Additionally, sequencing using Oxford Nanopore revealed targeted exon 23 deletion as the most prevalent …

In Vitro Mitral Valve Model With Unrestricted Ventricular Access: Using Vacuum To Close The Valve And Enable Static Trans-Mitral Pressure, Sam E. Stephens, Alexander J. Kammien, Jacob C. Paris, Alexis P. Applequist, Neil B. Ingels, Hanna K. Jensen, Drew E. Rodgers, Charles R. Cole, Jonathan F. Wenk, Morten O. Jensen

Biomedical Engineering Faculty Publications and Presentations

Current in vitro models of the left heart establish the pressure difference required to close the mitral valve by sealing and pressurizing the ventricular side of the valve, limiting important access to the subvalvular apparatus. This paper describes and evaluates a system that establishes physiological pressure differences across the valve using vacuum on the atrial side. The subvalvular apparatus is open to atmospheric pressure and accessible by tools and sensors, establishing a novel technique for experimentation on atrioventricular valves. Porcine mitral valves were excised and closed by vacuum within the atrial chamber. Images were used to document and analyze closure …

Blood–Brain Barrier Breakdown And Astrocyte Reactivity Evident In The Absence Of Behavioral Changes After Repeated Traumatic Brain Injury, Celeste Dunn, Nasya Sturdivant, Sara Venier, Syed Ali, Jeffery Wolchok, Kartik Balachandran

Biomedical Engineering Faculty Publications and Presentations

Repeated traumatic brain injuries (TBIs) cause debilitating effects. Without understanding the acute effects of repeated TBIs, treatment options to halt further degeneration and damage cannot be developed. This study sought to examine the acute effects of blood–brain barrier (BBB) dysfunction, edema, inflammation and behavioral changes after either a single or double TBI using a C57BL/6 mouse model. We examined the effects of one or two TBIs, of either a mild or moderate severity. Double injuries were spaced 7 days apart, and all analysis was performed 24 h post-injury. To examine edema and inflammation, protein levels of glial fibrillary acidic protein …

Experimental And Analysis Of Electromagnetic Characterization Of Biological And Non-Biological Materials In Microwave, Millimeter-Wave, And Terahertz Frequency Bands, Nagma Vohra

Graduate Theses and Dissertations

The goal of this research is to characterize the electromagnetic properties of biological and non-biological materials at terahertz (THz), millimeter-wave, and microwave frequency bands. The biological specimens are measured using the THz imaging and spectroscopy system, whereas the non-biological materials are measured using the microwave and millimeter-wave free-space system. These facilities are located in the Engineering Research Center at the University of Arkansas. The THz imaging system (TPS 3000) uses a Ti-Sapphire laser directed on the photoconductive antennas to generate a THz time domain pulse. Upon using the Fourier Transform, the spectrum of the pulsed THz signal includes frequencies from …

A Portable Point-Of-Care Device Using Joule Heating And Latent Energy Storage For The Temperature Regulation Of Isothermal Nucleic Acid Amplification Tests, Aubrey Lynn Schultz

Graduate Theses and Dissertations

Accurate and early diagnosis of infectious diseases extremely important. Rapid diagnosis allows for effective treatment and increases the chance for recovery without complications. Additionally, the ability to test the populace frequently, swiftly, and affordably significantly aids in containing wide-scale outbreaks. In terms of specificity and sensitivity, nucleic acid amplification tests (NAAT) are one of the best options for diagnosing infectious diseases. Isothermal NAATS present a unique opportunity to create diagnostic tests deployed at a Point-of-Care (POC) level. Specifically, loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA) have the potential to deliver reliable POC diagnostics in low-resource settings. When designing …

Quantifying Mucosal Hemodynamics In A Murine Model Of Ulcerative Colitis With Diffuse Reflectance Spectroscopy, Elizabeth A. Bullard, Ariel I. Mundo, Shelby N. Bess, Kathryn P. Miller

Biomedical Engineering Undergraduate Honors Theses

Ulcerative colitis (UC) is a gastrointestinal, autoimmune disease that causes ulceration and inflammation of the colon with an incidence 10 out of every 100,000 people in North America and Western Europe. Though the exact etiology is uncertain, a number of studies have shown that inflammatory cells along with environmental factors, genetics, and lifestyle habits can contribute to the sustained inflammatory response. In order to determine the cellular mechanism behind relapse and remission of UC, researchers have frequently employed immunohistochemistry, western blotting and gene sequencing, but these destructive analysis methods require the removal of a sample, necessarily limiting these methods to …

New Force Transducer For Mitral Valve Chordae Tendinea, Joseph Berryman

Biomedical Engineering Undergraduate Honors Theses

In order to inform the future of mitral valve repair and replacement, more investigation into the mechanics of the sub-valvular structure is needed. Understanding the roles of each chord during valve closure requires a sensor capable of detecting these small forces with enough sensitivity to determine the characteristics of each of the chordal types. The focus of the cantilever force transducer is to maximize this sensitivity while also minimizing the invasiveness of the sensor on the overall function of the chord. The design utilizes flexible yet strong 3D printed resin and cantilever arms to improve the strain exerted on a …

Use Of 3d-Printed Surgical Spoons Compared To Other Cystotomy Methods In Dogs, Davina D'Angelo

Animal Science Undergraduate Honors Theses

Bladder stones, also known as uroliths, are not an uncommon condition in domestic dogs. To remove these uroliths, which occur in various sizes, shapes, and compositions, veterinarians will perform a surgical procedure called a cystotomy. A cystotomy consists of creating a small incision into the lumen of the urinary bladder and the utilization of various methods to extract the uroliths. For general veterinary practitioners, the laparoscopic-assisted technique is unavailable. As a result, the methods available for urolith extraction are often limited to flushing the stones out by inserting a urinary catheter through the urinary tract and the use of off-label …

Promotion Of Human Schwann Cell Proliferation Using Heparin/Collagen Coated Nerve Conduits, John Magness

Chemical Engineering Undergraduate Honors Theses

Often in the aftermath of an injury or surgery, the sense of touch and muscle control is lost in the affected area as nerves are damaged or severed and fail to grow back completely. The regeneration of the nerve cells can be promoted by treating the nerves with nerve conduits. Nerve conduits are hollow cylinders of bio-compatible materials that can be surgically implanted to the disconnected nerve to promote and direct the growth of nerves. The objectives of this research are to investigate the ability of nerve conduits treated with layer-by-layer coatings to promote the growth of Schwann cells, to …

Development Of An Integrated Salt Cartridge-Reverse Electrodialysis (Red) Device To Increase Electrolyte Concentrations Of Human Blood Flow To Power Biomedical Devices, Caroline Campbell

Chemical Engineering Undergraduate Honors Theses

Emerging technologies in nanotechnology and biomedical sciences have led to an increase in biomedical implantable devices including cardiac pacemakers, artificial organs, drug pumps, and sensors. These devices require continuous stable and reliable power to operate, which creates the demand for the need to find a safe, reliable, and stable power source. A promising avenue for a power source for these devices is a miniaturized reverse electrodialysis (RED) biopower cell design that utilizes the salinity differences between bloodstreams that flow inside the human body. Initial results of the RED system demonstrate that higher gradient salinity differences between streams lead to a …