Biomedical Devices and Instrumentation Commons^™

Effects Of A Passive Assistive Hamstring Device On Overground Running Kinematics And Hamstring Activation., Quinn Castner

All Theses

Hamstring strain injuries are among the most common and recurring injuries in sports, occurring most often during the terminal swing phase of gait. Despite progress in rehabilitation, the incidence of injury has only increased, suggesting a need for a novel intervention. We designed a passive, assistive, wearable device with two specific criteria in mind: to offload the hamstrings during running, and do so without hindering normal kinematic patterns. The device consists of an adjustable elastic band anchored proximally at the waist and distally just above the ankle joint center. It stretches and shortens with the hamstrings, providing passive hip extension …

Development Of Low-Cost Triaxial Force Sensor For Measurement Of Human-Exoskeleton Interaction Forces, Hamdan Khan Sarvathullah

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Contemporary research suggests that shear force is a major contributor to discomfort and pressure injury. However, the variation of shear forces during human-exoskeleton interaction dynamics is a highly unexplored field. The high cost of commercial triaxial force sensors may be a major factor in the notable lack of research in this field. Therefore, in this paper, we present a low-cost, 3D-printed triaxial force sensor designed specifically to measure the triaxial interaction forces between an exoskeleton and its user. The triaxial force sensor uses Carbon-Black/Silicone Rubber (CB/SR) strings to measure shear forces, whereas the normal force is measured with a Force …

Crevice Corrosion Mechanisms Of Cocrmo Alloys In Orthopedic Implants: Retrieval Analysis, Nano-Tribocorrosion And Cellular Responses, Hwaran Lee

All Dissertations

Mechanically assisted corrosion and non-mechanically (chemically) driven corrosion in modular junctions of orthopedic implants using cobalt-chromium-molybdenum (CoCrMo) alloys remain clinical concerns and may contribute to implant failure. The underlying corrosion mechanisms are not yet fully understood, leaving a critical research gap. We hypothesized that corrosion in modular junctions may be driven by aggressive local environments, including fretting, metal ion release (cobalt ion, Co²⁺), low pH and reactive oxygen species (ROS). This dissertation aims to (1) analyze corrosion modes and potential causes in modular junctions; (2) identify chemically driven corrosion modes on CoCrMo alloys using simulated inflammatory modular taper …

Impact Of Shear Flow On Marine Biofilms Using Hyperspectral Imaging, Shantanu Mahesh Kore

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Various microbial communities in marine biofilms cause biofouling on submerged surfaces, posing challenges to marine industries. Despite their ecological and economic importance, biofilms' biomechanical and biochemical responses to hydrodynamic shear stress are insufficiently understood, particularly in dynamic flow conditions. To fill this gap, our study uses an innovative fiber-optic hyperspectral imaging (HSI) system and a supercontinuum laser source to examine marine biofilms' structure, composition, and detachment behavior at different shear stress levels.

To detect spectral and spatial heterogeneity in live biofilms without labeling, we created a custom imaging pipeline that captures reflectance spectra in the 600-850 nm range, targeting microbial …

Development Of Translational Microscale Systems To Interrogate How Biophysical And Biochemical Cues Alter The Phenotype Of Hormone Positive Breast Cancer, Braulio Ortega Quesada

All Dissertations

Cancer is a complicated disease and one in every three diagnoses are women with breast cancer. Recent research shows that the progression of cancer depends strongly on interactions with other non-cancerous cells and non-cellular components. Metastasis, the spread of cancer to other parts of the body, is a key step in cancer progression and makes treatment harder, leading to poor response to treatments culminating in death in ~90% of patients. This dissertation focused on creating a series of microdevices as novel pre-clinical models of breast cancer. Two different devices were fabricated to (1) study how exposing cancer cells to the …

Modeling Instrument Design Risks In Medical Device Reprocessing, Manuel Andres Gutierrez

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Medical device reprocessing is an essential practice in healthcare delivery. While FDA regulations require device manufacturers to develop and validate reprocessing procedures, the increasing complexity of medical device designs and their use environments can increase the risks of inadequate reprocessing and associated device malfunctions and potential patient injury. While some design features present known difficulties for reprocessing, critical information needed to define relative risks or feature-specific parameters that increase or decrease risks of inadequate reprocessing is lacking. There is an urgent need for tools to quantify and predict reprocessing risks associated with design features used in surgical instruments.

The broad …

The Effect Of Pressure Gradients On Perceived Discomfort, Zachary Bush

All Theses

Introduction:

A pressure gradient is where high and low pressure meet. It is responsible for displacement and irritation of the skin commonly caused by tight bandages, bracelets, or socks. The irritation is at the edge where the skin is displaced by the high and low pressure. An analysis of the effect pressure gradients have on discomfort would have significant medical relevance for any device, fixture, or clothing pressed against the skin at high pressure. This primarily includes prosthetic and orthotic devices.

The bottom surface of the heel provides a naturally circular, uniform pressure profile. This makes it the optimal testing …

Expandable Tissue-Engineered Living Surgical Pulmonary Heart Valve For Pediatric Patients, Jacob M. Lautenschlager

All Theses

Cardiovascular disease is the most common cause of mortality in developed countries, with 607.74 million cases globally in 2020.^1,2 Advances in medicine have changed the current demographic suffering from heart valve disease into an aging population suffering from degenerative heart valve disease, creating a growing population treated by surgical or transcatheter intervention.^3-6 Current treatments of valvular heart disease are therefore directed toward valve replacements for the adult population, leaving a treatment gap for pediatric patients suffering from heart valve disease.^7-10

Congenital heart defects are defined as structural abnormalities of the heart or intrathoracic great vessels and are …

Computer Vision Algorithms For Assessment Of Surgical Suturing Skill Using Hand And Needle Motion, Jianxin Gao

All Dissertations

Surgical suturing skill assessment is a crucial part of surgical education. Vascular surgery educators have developed a simulation-based examination called Fundamentals of Vascular Surgery, which includes a clock-face model for assessing open surgical suturing skills. The clock-face model, however, requires the valuable time of expert surgeons to determine examinees' skills. Moreover, expert surgeons have different judgments for appropriate sutures, which leads to inconsistent grading. These limitations motivate us to use sensors to measure examinees' needle motions and hand motions during the clock-face suturing exercises, and then use the measurements for objective suturing skill assessment.

To assess suturing skills based on …

Advancements Of A Breast Tissue Marker And Localization System, Azrin Jamison

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Breast cancer has become the most prominent cancer worldwide in women. Annual mammograms are encouraged for women of high risk to increase early detection allowing for lumpectomies rather than mastectomies to occur. Prior to a lumpectomy, a biopsy must be taken to determine if the tissue is cancerous, and a breast cancer biopsy marker (BBM) is left in the region of possible cancerous tissue. Wire localization has been the gold standard for localizing these BBMs. However, due to the reported patient discomfort and logistical inefficiencies faced by healthcare providers (HCP), non-wire localization solutions have been recently developed. This study aims …

Hand Movement Analysis For Surgical Suturing Skill Assessment, Amir Mehdi Shayan

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To enhance patient safety, surgical education is increasingly incorporating simulation for formative skills assessment and training. However, many standardized assessment tools rely on human raters for performance assessment, which is resource-intensive and subjective. Simulators that provide automated and objective metrics from sensor data can address this limitation. This thesis presents an instrumented bench suturing simulator, patterned after the Clock Face (CF) radial suturing model from the Fundamentals of Vascular Surgery (FVS), for automated and objective assessment of open suturing skills by particularly focusing on biomechanical analysis of hand movements. For this research, 97 participants (35 attending surgeons and fellows, 32 …

Experimental And Computational Platforms For Studying Systems Mechanobiology, Brendyn Miller

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Mechanical stimulation through physical activity has been shown to play an important role in treating and preventing several non-communicable diseases such as hypertension, lower back pain (LBP), type-2 diabetes mellitus, and several cancers. This is accomplished through the regulation of cellular behavior and tissue remodeling within the body at both the micro- and macro-scale levels. The goal of mechanobiology research is to gain in-depth knowledge and understanding of how cells sense physical forces in conjunction with other biochemical cues and translate those factors into important biological functions that either maintain tissue homeostasis or lead to pathological states. Understanding these processes …

In Vitro Bioreactor For Mechanical Control And Characterization Of Tissue Constructs, Samuel Coeyman

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Heart failure (HF) currently affects over 6 million Americans, 50% of whom die within 5 years of their initial diagnosis. A major contributor to the onset of HF is cardiac fibrosis in the myocardium, which arises when fibroblasts (FBs) are activated in response to heightened mechanical stress from overload conditions like hypertension. Activated FBs remodel the extracellular matrix (ECM) and secrete ECM proteins including collagen. FB remodeling has been studied in the past by applying forces and/or deformations to three-dimensional, cell-seeded gels and tissue constructs in vitro. Unfortunately, previous stretching platforms have traditionally not enabled mechanical property assessment to be …

Highly Adherent Antimicrobial Coatings For Orthopedic Implants, Mikhail Bredikhin

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Fracture-related infections (FRIs) are the most devasting sort of complications associated with fracture fixation devices, as they lead to patients’ morbidity, prolonged hospitalization, amputations, and even death.External fixators additionally suffer from pin site infections (PSIs), which initiate at the skin entry points of the skin-metallic pin interface present in the external fixation of the damaged bones, often causing deep tissue infection and osteomyelitis. Small percutaneous pins, commonly known as Kirschner wires (K-wires), are used to treat complex fractures and deformities.They are drilled inside the diseased bone for the healing period and are left protruding outside the skin for fixation adjustments …

Porous Silicon Photonics For Label-Free Interferometric Biosensing And Flat Optics, Tahmid Hassan Talukdar

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This dissertation uses porous silicon as a material platform to explore novel optical effects in three domains: (i) It studies dispersion engineering in integrated waveguides to achieve high performance group index sensing. With proper design parameters, the sensor waveguides can theoretically achieve 6 times larger group index shift compared to the actual bulk effective refractive index shift. We demonstrate the guided mode confinement factor to be a key parameter in design and implementation of these waveguides. (ii) It explores multicolor laser illumination to experimentally demonstrate perceptually enhanced colorimetric sensing, overcoming the limitations faced by many contemporary colorimetric sensors. Our technique …

Design Of A Four Channel Pulsatile Perfusion Bioreactor For Ex-Vivo Study Of Vascular Grafts, Thomas M. Fair

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Cardiovascular diseases are the leading cause of death in the United States. Atherosclerosis in peripheral arteries is a major contributing factor. Autologous saphenous vein grafts are the most common bypass grafts for treating peripheral artery diseases. A quarter of these grafts fail within a year, and around half have failed within 10 years of the initial surgery. Graft failure is attributed to the development of intimal hyperplasia indicated by the migration and proliferation of vascular smooth muscle cells, fibroblasts, and the deposition of extracellular proteins.

Increases in flow, pressure, the pulse frequency, and the differential of pressure that model an …

Portable U-Bent Optical Fiber Biosensor For Detecting Microcystin-Lr, Quan Dio Anh Le

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Cyanobacteria are the only known prokaryotes that can photosynthesize. Due to their unique ability, they are important entities in the global carbon and nitrogen cycles. However, two factors can turn cyanobacteria into a nuisance. In general, eutrophication is the process that supplies external nutrients that are needed for cyanobacteria blooms into bodies of water from the surrounding environment. Climate warming intensifies this process by producing carbon dioxide, methane, and nitrous oxide. With cyanobacteria blooms occurring worldwide, they are becoming a bigger threat to human health, and there has been increased interest in detecting cyanobacteria and their toxic byproducts.

For instance, …

Time-Lapse Observation Of Sarcomeric Addition In Hypertrophic Models Based On A Tissue Like Cardiomyocyte Culture, Ailin Wei

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Cardiac hypertrophy is the response of the heart to increased mechanical stress exerted on the heart. In a hypertrophic heart, the muscles elongate or/and thicken with cardiomyocytes growing sizes. It is assumed that cardiomyocytes elongate by adding sarcomeres in series; the cardiomyocytes thicken with the addition of sarcomeres in the parallel position.

In this study, a tissue-like culture model was achieved with step-like ICDs. Uniaxial static stretch has been applied to our unique culture model for studying mechanical-load-induced cardiac hypertrophy. Hypertrophic responses of these cardiomyocytes have been confirmed on transcriptional and translational levels in our tissue-like model. The two-photon excitation …

Development Of Solution Blow Spun Nanofibers As Electrical And Whole Cell Biosensing Interfaces, Craig Levar Miller

All Dissertations

Infectious pathogens place a huge burden on the US economy with more than $120 billion spent annually for direct and indirect costs for the treatment of infectious diseases. Rapid detection schemes continue to evolve in order to meet the demand of early diagnosis. In chronic wound infections, bacterial load is capable of impeding the healing process. Additionally, bacterial virulence production works coherently with bacterial load to produce toxins and molecules that prolongs the healing cycle. This work examines the use of nonwoven polymeric conductive and non-conductive nanofiber mats as synthetic biosensor scaffolds, drug delivery and biosensor interface constructs. A custom-made …