Biomedical Engineering and Bioengineering Commons^™

Numerical Investigation Of Subglottal Stenosis Effects On Human Voice Production, Dariush Bodaghi

Electronic Theses and Dissertations

This dissertation aimed to advance knowledge of how subglottal stenosis impacts voice production physiology. An in-house fluid-structure-acoustic interaction approach based on the hydrodynamic/acoustic splitting technique was employed. This technique was rigorously verified for simulating phonation by matching the acoustic behavior to a compressible flow solver for phonation-relevant geometries. Simulations of an idealized 2D vocal tract model demonstrated the effects of supraglottal acoustic resonance on vocal fold kinematics and glottal flow waveform. Results showed that the acoustic coupling between higher harmonics and formats generated pressure oscillations, modifying vocal fold dynamics and glottal flow rate.

A major novelty was the incorporation and …

Exploring The Use Of Audible Sound In Bone Density Diagnostic Devices, Evan J. Bess

Electronic Theses and Dissertations

Osteoporosis is a medical condition in which there is a progressive degradation of bone tissue that correlates with a characteristic decrease in bone density (BD). It is estimated that osteoporosis affects over 200 million people globally and is responsible for 8.9 million fractures annually. Populations at risk for developing osteoporosis include post-menopausal women, diabetic patients, and the elderly, representing a large population within the state of Maine. Current densitometric and sonometric devices used to monitor BD include quantitative computed tomography (QCT), dual-energy x-ray absorption (DXA), and ultrasound (QUS). All methods are expensive and, in the cases of QCT and DXA, …

Characterization Of Mammographic Dense Tissue Sub-Types Using Classification Algorithms On Metric Space Technique Output Functions, Madison Raza

Electronic Theses and Dissertations

In recent years breast cancer has become the leading cause of global cancer incidence. One of the most common forms of screening is through the use of digital x-ray screening mammography. Risk assessment models which help predict a patient’s risk of developing breast cancer rely mainly on patient history and qualitative breast density assessment from screening. The 2D wavelet transform maxima modulus (2D WTMM) method uses a sliding window approach to quantify the spatial organization of underlying mammographic tissue according to Hurst- exponent ranges (H) as fatty (H ≤ 0.45), healthy dense (H ≥ 0.55) and …

Development And Characterization Of Shear Thinning Cnf-Tempo Hydrogels For Use In Aquaculture Vaccines, Jacob A. Holbrook

Electronic Theses and Dissertations

Aquaculture has shown significant growth within the past few decades and is expected to continue expanding rapidly as the global demand for fish consumption continues to increase. A significant loss within the aquaculture industry is due to pathogen transmission within the farm systems. These pathogens are mitigated through various methods that are not cost effective or have limited protection. The most common method of pathogen mitigation is through oil-based injection vaccines as they provide even protection across vaccinated fish and provides the longest protection compared to other vaccination methods. These oil-based injection vaccines are not without their flaws as they …

Designing And Modeling A Fail-Safe Mechanism To Be Used In Attachment Of A Transcutaneous Femoral Implant To A Prosthetic Device, Emma Sperry

Electronic Theses and Dissertations

Amputations are quite common and even modern prosthetic devices are plagued by problems. There are approximately 2 million people living with limb loss in the U.S. and on average 185,000 amputations occur yearly. Common attachment mechanisms for external prosthetic components to a residual limb, that is, sockets, pose numerous challenges. Issues include skin irritation, discomfort, socket fit issues, and immobility. Issues include skin irritation, discomfort, socket fit issues, and immobility. Transcutaneous implants have great potential as a connection method for external prosthetic components to a residual limb but because the implants are typically solid, they correlate to extremely high infection …

Longitudinal Case-Control Study Of Mammographic Breast Tissue Subtypes, Kendra Batchelder

Electronic Theses and Dissertations

Breast density is a known risk factor for breast cancer. However, there has been limited research on potential subtypes of mammographic dense breast tissue to identify areas of active dense tissue that is structurally reorganizing and links to cancer dynamics, versus areas of passive dense tissue which remains organized. We hypothesize that the amounts of subtypes of mammographic dense tissue and the associated rate of change through time could provide insights into breast cancer risk. A retrospective study was conducted to investigate breast cancer using longitudinal screening mammograms and accompanying pathology reports collected in 2015. Patients were matched by age …

Nanocellulose Based Foams For Low-Cost Disposable Medical Applications, Dominic Kugell

Electronic Theses and Dissertations

Polyurethane foams have been a staple material for their use in medical positioners, such as post-surgery elevation pillows as well as specific tailored positioners for their use during surgery. Polyurethane foams are preferred because of their lower cost compared to other petroleum derived foams, their versatility, and suitable mechanical properties. However, the environmental impact, including both cost and perception, of these foams is immense. Therefore, alternatives are being explored with biopolymers emerging as a promising class of materials. Cellulose is one such polymer that has recently demonstrated desirable properties. In this study, cellulose nanofibrils (CNF), a household foaming agent, and …

Hybrid Power Spectral And Wavelet Image Roughness Analysis, Basel White

Electronic Theses and Dissertations

The Two-Dimensional Wavelet Transform Modulus Maxima (2D WTMM) sliding window methodology has proven to be a robust approach, in particular for the extraction of the Hurst (H) roughness exponent from grayscale mammograms. The power spectrum is a computational analysis based on the Fourier transform that can be used to estimate the roughness of a scale-invariant image or region via the calculation of H. We aim to examine how the calculation of H in fractional Brownian motion (fBm) images and mammograms can be improved. fBm images are generated for H ∈ [0.00,1.00] for testing through the previous 2D …

Engineering The Development Of Neuromuscular Circuitry On-Chip, Inès Khiyara

Electronic Theses and Dissertations

Neuromuscular development happens in a complex interconnected network of biochemical pathways. This complicated embryonic development follows a strong, functional, and precise neuromuscular network that has interested both scientists and engineers who seek to better understand neuromuscular diseases. These disorders can be inherited or acquired, and their severity and mortality can vary. Researchers first studied the neuromuscular network from an organismal perspective, and more recently from an embryological, cellular, molecular, biochemical, and genetic perspective. From these studies, the fundamental principles of motor neuron pathfinding to muscles are widely understood, but the molecular drivers of specific nerve-muscle pairing remain unknown. Although in …

Multiscale Anisotropy Analysis Of Second-Harmonic Generation Imaging Of Pancreatic Cancer, Joshua D. Hamilton

Electronic Theses and Dissertations

Despite recent advancements in biomedicine, cancer is still the second leading cause of death in the United States. Early detection of cancer is critical to improving patient care, but there are risks of over screening caused by the need for surgical biopsies in many cancers for final diagnostics. Recent advancements in computer aided diagnostics for breast cancer screening has reduced the need for biopsies and resulted in earlier diagnoses which has lowered the mortality rate from breast cancer within the past two decades. Developing new computer aided diagnostic tools that can be applied to a vast majority of cancers would …

Using Shg Directionality To Characterize Collagen Alteration In Breast Cancer Tumor Microenvironment And Its Prognostic Applications, Betelhem Solomon Abay

Electronic Theses and Dissertations

Although breast cancer is a growing health concern worldwide, the challenge to minimize mortality rate partly comes from the heterogeneity in its pathological characteristics. The tumor microenvironment is a complex hub of signaling cascades that plays a key role for the progression of cancer to develop to metastatic stage. The extracellular matrix (ECM), as a major component of the tumor microenvironment, contains signatures that have cues to understand tumor progression. Here, the unique microstructural collagen alterations specific to reactive stromal/tumor cell interactions and interactions of reactive stromal fibroblasts with different tumor cell types MCF7A and MDA-MB-231 were investigated. Early alterations …

The Influence Of Processing And Additives On Cellulose Nanofiber Properties For Orthopedic Application, Mitchell P. Chesley

Electronic Theses and Dissertations

Current orthopedics are separated into three different classes of materials, metals, polymers, and ceramics. While these devices have had success throughout the years they are not without their faults. Metallic devices for example are usually extraordinarily stiff when compared with the surrounding bone. This difference in stiffness induces localized stress-shielding promoting cortical atrophy, which can lead to osteoporosis. Polymers while having the capacity of being biodegradable and bioabsorbable also have the potential to incite localized demineralization and weakness in surrounding bone. A result of breakdown byproducts not efficiently being evacuated from the area, which additionally acts as catalysts expediating the …

Developing And Characterizing A Novel Tempo Cnf Hydrogel Adjuvant And Delivery System For Aquatic Vaccines, Kora Kukk

Electronic Theses and Dissertations

Aquaculture is a large part of the food production sector which is greatly expanding. One of the largest losses in aquaculture is due to pathogens. Current solutions for protecting farmed finfish from pathogens can be very expensive with variable efficiency. Current disease prevention strategies include vaccination. Types of vaccines include immersion vaccines, feed vaccines, and injectable vaccines. The most popular solution is oil-based injectable vaccines due to its protection. However, the oil-based adjuvant used in most of these formulations causes adverse reactions in the fish including reduced growth. These vaccines require multiple administrations throughout the fish’s lifetime causing unwanted handling …

Continuous, Non-Destructive Detection Of Surface Bacterial Growth With Bioinspired Vascularized Polymers, Brandon Dixon

Electronic Theses and Dissertations

Reducing or eliminating bacteria on surfaces is vital for medical devices, drinking water quality, and industrial processes. Evaluating surface bacterial growth at buried interfaces can be problematic due to the time-consuming disassembly process required for obtaining standard surface samples. In this work, a continuous, non-destructive, and reusable method was developed to detect surface bacterial growth at buried interfaces. Inspired by vascular systems in nature that permit chemical communication between the surface and underlying tissues of an organism, bacterial-specific signals diffusing from cells on the surface were detected in channels filled with an inert carrier fluid embedded in a polymer matrix. …

Development Of A New Method For Cell Spheroid Formation Through A Hydrogel Dipping Process, Aimee L. Co

Electronic Theses and Dissertations

Traditional cell culture systems make use of two-dimensional (2D) monolayer studies which are simple, cheap, and have been successful for a various cell types. However, since this does not reflect on the in vivo physiology, studies have branched out to use three-dimensional (3D) cell culture systems. 3D cell culture allows for studies which make use of the cell connectivity, polarity, and tissue architecture. The use of 3D aggregates called spheroids is one of the most common and versatile of these methods. There are various techniques for spheroid formation and chosen technique is often decided based on the decided spheroid use …

Investigation Of Mass-Manufactured Nanostructured Material For Contamination Detection Via Structural Color Analysis, Oisin Biswas

Electronic Theses and Dissertations

The spread of the SARS-CoV-2 virus has underlined the importance of monitoring surface contamination of infectious elements on commonly used surfaces. Current monitoring methods of surfaces are both lengthy and expensive. The work in this project took advantage of the optical phenomenon of structural color to develop a rapid, low-cost, and contactless method of surface contamination detection. To accomplish this, a mass-produced material imprinted with a nanostructured pattern capable of exhibiting this structural color phenomenon was used. Structural color, or the bands of color that appear as different wavelengths of light reflect off a textured surface, can vary as a …

Gradient Generating Microfluidic Coculture System For Disease Modeling And Neural Development, Phaneendra Chennampally

Electronic Theses and Dissertations

Cellular microenvironment or cell niche plays an important role in developmental biology and disease pathophysiology. Physical or chemical signals in microenvironment drive the cellular activity. These signaling molecules are generated from the surrounding cells/tissues as part of intercellular communication; a fundamental property of a cell. Dynamic profile of these signaling molecules in the microenvironment plays a pivotal role in transfer of molecular information from cell to cell in disease proliferation or fate determination. Recapitulating these signaling cues in an in vitro study is difficult to achieve using standard cell culture techniques. However microfluidic systems are capable of addressing these issues, …

Development Of A Novel Haptic Feedback System For Gait Training Applications, Mohsen Alizadeh Noghani

Electronic Theses and Dissertations

Until recently, study and correction of motor or gait functions required costly sensors and measurement setups (e.g., optical motion capture systems) which were only available in laboratories or clinical environments. However, due to (1) the growing availability and affordability of inertial measurement units (IMUs) with high accuracy, and (2) progress in wireless, high bandwidth, and energy-efficient networking technologies such as Bluetooth Low Energy (BLE), it is now possible to measure and provide feedback in real-time for biomechanical parameters outside of those specialized settings. To enable gait training without an expert who can provide verbal feedback, augmented feedback, which is divided …

Segmentation And Statistical Analysis Of Imaged And Simulated 3d Chromosome Territories, Hannah Varney

Electronic Theses and Dissertations

With advances in microscopy in the 21st century, more accurate measurements of the morphology and position of chromosome territories (CTs) during interphase within the cell nucleus can be obtained. These measurements have determined that CTs are non-randomly positioned, and their position and shape can change during diseases like breast cancer, pancreatic cancer, and Huntington’s Disease. The 2.5D Wavelet Transform Modulus Maxima segmentation method uses multi-scale edge detection to accurately segment objects in 3D images to find variables such as surface area, volume, and diameter without assuming a spherical or ellipsoidal shape. Measurements of centroid distance, shell distance and radial distance …

Manipulation Of Particles And Fluid With Surface Acoustic Waves, Joel Scott Tewksbury

Electronic Theses and Dissertations

Small biomolecules can be challenging and expensive to isolate and manipulate, but they may be the key for developing more efficient diagnostic tools for the detection of biomarkers, such as those associated with pancreatic cancer. Pancreatic cancer has a survival rate of less than 10% five years after diagnosis. For this reason, the research and establishment of cheap, effective screening tools are highly desired. One promising method of screening is separating and identifying biomarkers in a patient’s blood that are indicative of pancreatic cancer. The purpose of this project is to develop a system using surface acoustic waves (SAWs), in …

Gait Rehabilitation Using Biomechanics And Exoskeletons, Jacob Bloom

Electronic Theses and Dissertations

A healthy gait is often taken for granted when walking. However, if a stroke, spinal cord injury (SCI), or traumatic event occurs the ability to walk may be lost. In order to relearn how to walk, gait rehabilitation is required. Including arm swing in gait rehabilitation has been shown to help in this process. This thesis presents two tasks to investigate the mechanics of arm swing and ways to provide assistance to induce arm swing in gait rehabilitation.

The firsts task completed was a study on the effects of forearm movement during gait. Twelve healthy subjects walked under three conditions …

Growth Of Perkinus Marinus By Bioreactor Fermentation, Caitlin Murphy

Electronic Theses and Dissertations

Perkinsus marinus is a marine protozoan responsible for “Dermo” disease in the eastern oyster species, Crassostrea virginica. P. marinus has been detected along the Atlantic Coast of the United States and Mexico. In laboratory studies, many parasites need to be maintained in vivo, which complicates the study of the organism. However, In vitro cell culture for P. marinus at a scale of 1 mL was established in 1993 by several groups with the 1995 optimization (Gauthier & Vasta, 1993, 1995) considered the gold standard for small scale growth of this species. In addition to its importance as a …

Nanocellulose Conduits For Enhanced Regeneration Of Peripheral Nerve Injuries, Nicklaus R. Carter

Electronic Theses and Dissertations

Peripheral neuropathy is estimated to afflict 20 million people in the United States. Most cases of neuropathy result from physical injuries and trauma arising from automobile accidents and war. Peripheral nerves have the intrinsic ability to regenerate over time, bridging the injury gap. However native regeneration is limited to a distance of only a few millimeters. Current methods utilized to assist in the regeneration of peripheral nerves over distances exceeding those amenable to native repair include nerve autografts and allografts, and implantation of conduits. Nerve autografts are regarded as the most effective method but require a second surgical site to …

Handling And Manipulation Of Water- And Air- Borne Biological Samples Using Liquid-Infused Surfaces, Daniel P. Regan

Electronic Theses and Dissertations

Research on novel materials to handling water- and airborne samples for biological threats analysis is in great demand due to the COVID-19 pandemic. Work conducted on a new field of material science, called liquid-infused surfaces, demonstrate strong potential for the handling and manipulation of biological samples. As a result of the field’s infancy, only a limited number of studies have explored how liquid-infused surfaces can apply droplet manipulation strategies to address real-world problems. Presented in this dissertation are two platforms that leverage liquid-infused surfaces to address the challenges associated with handling water- and airborne biological samples. When dealing with waterborne …

Fabrication Of Silicon Microneedles For Dermal Interstitial Fluid Extraction In Human Subjects, Caleb A. Berry

Electronic Theses and Dissertations

The goal of this project is to design and develop a fabrication process for silicon microneedle arrays to extract dermal interstitial fluid (ISF) from human skin. ISF is a cell- free, living tissue medium that is known to contain many of the same, clinical biomarkers of general health, stress response and immune status as in blood. However, a significant barrier to adoption of ISF as a diagnostic matrix is the lack of a rapid, minimally invasive method of access and collection for analysis. Microfabricated chips containing arrays of microneedles that can rapidly and painlessly access and collect dermal ISF for …

Rapid Prototyping To Roll-To-Roll Manufacturing Of Microfluidic Devices, Amber Lee Boutiette

Electronic Theses and Dissertations

Microfluidics constitutes a widely applicable field of enabling technologies with great potential to revolutionize healthcare and biotechnology. The ability to miniaturize and parallelize processes with microfluidics is seen as a solution for many problems with diagnostics technologies and accessibility. Unfortunately, fabricating microfluidics often require extremely expensive, time consuming, and specialized high-precision methods, making both prototyping and commercial-scale mass manufacturing difficult to accomplish. In this work, we evaluate the feasibility of using a unique roll-to-roll (R2R) micropatterning manufacturing process coupled with Additive Manufacturing (3D printing) to rapidly prototype and produce microfluidic devices at high-volume on film or paper backings for applications …

Characterization Of Nano-Cellulose Based Composites For Biomedical Applications, Mitchell P. Chesley

Electronic Theses and Dissertations

The number of orthopedic surgeries performed globally has steadily increased over the past decade due to the standardization of procedures as well as technological advancements. During this time orthopedic devices have been composed predominantly of metals, such as Titanium, Vanadium, Molybdenum, and Stainless steel, as well as their alloys, due to the high strength and durability of these materials. However, metals may, in fact, be suboptimal for orthopedic devices. For example, metals exhibit Young’s modulus much greater than the surrounding bone, inducing localized stress-shielding promoting cortical atrophy, which can lead to osteoporosis. In recent years polymers have been successfully explored …

Design, Construction And Application Of A Home-Built, Two-Photon Microscope, William P. Breeding

Electronic Theses and Dissertations

Two-photon microscopy (TPM) is a powerful, versatile imaging modality for the study of biological systems. This thesis overviews the relevant physics involved in TPM, design considerations and process of constructing a home-built, two-photon microscope, and provides a set of procedures to operate the system. Furthermore, this work explores several applications of TPM through the study of single-cell metabolism and imaging the cellular-material interface. Explored in particular depth was the imaging of cellulose nanofiber (CNF) materials, with the goal of understanding the three-dimensional nature of fibroblast cell growth when embedded within the materials. This work uncovered several optical properties of CNF, …

3d Printed Bioinspired Vascularized Polymers, Kayla Marquis

Electronic Theses and Dissertations

Biological vascular systems contain a network of three-dimensional channels that transport and deliver necessary nutrients throughout the organism. These systems are complex, adaptable, and possess the ability to detect and respond to external stimuli as needed. In this work, we mimic the complexity and adaptability of biological systems by incorporating vascular systems into polymeric materials. Vacant channels are created using a fugitive ink technique along with 3D gel printing. Upon completion of vascular channel construction, proof of principle testing is performed by inoculating the polymeric surface with bacteria and adding antibiotics to the vascular channels. The system is then characterized …

Nanocellulose Fibers As A Potential Material For Orthopedic Implantation Application, David Gregg Holomakoff

Electronic Theses and Dissertations

The field of biomaterials is of immense importance and will continue to grow and develop in the coming years. Novel materials, as well as new approaches for use of existing materials, are sought after now more than ever. Current metal orthopedic implants have an over engineered stiffness and Young’s modulus, causing a phenomenon called stress shielding. Metal implants absorb the majority of force typically exerted on bone and the osteocytes within. When osteocytes fail to sense mechanical forces bones become less dense and weaken, causing possible fracture and other complications. A new orthopedic material is needed matching Young’s modulus of …