Biomedical Engineering and Bioengineering Commons^™

Robust Quantification Of Cortical Hemodynamic Response To Tactile Stimulation: A Comprehensive Fnirs Methodology To Mitigate Physiological Confounds, Mohsen Hozan

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation establishes a quantitative framework for studying somatosensory processing using functional Near-Infrared Spectroscopy (fNIRS), with a focus on applications in neurorehabilitation. The central aim is to investigate how the brain's hemodynamic response is modulated by the velocity of patterned tactile stimulation. While fNIRS is a promising neuroimaging tool, its data quality is often compromised by physiological noise and motion artifacts, challenging the reliability of its findings and hindering the development of effective, quantifiable neurotherapeutics.

Two preliminary investigations informed the final experimental design. The first pilot study confirmed that pneumotactile stimulation of the hand, during both passive (somatosensory) and active …

Laser-Induced Graphene Sensor For The Electrochemical Detection Of Acetaminophen, Abdellatif Ait Lahcen, Mazhar Sher, Sikander Ameer, Gymama Slaughter

Center for Bioelectronics Publications

Here we present a simple and efficient method for fabricating laser-induced graphene (LIG) electrodes for the electrochemical detection of acetaminophen (AAP), a crucial analgesic and antipyretic that can become toxic at elevated concentrations. Unlike conventional sensors that require intricate chemical modifications, the fabricated LIG-based sensor eliminates the need for functionalization, offering a streamlined sensing solution. The LIG electrodes were characterized using scanning electron microscopy, energy-dispersive spectroscopy, and Raman spectroscopy, which confirmed the formation of a highly porous graphene network with excellent purity and conductivity. Cyclic voltammetry analysis with a ferricyanide redox probe revealed a large electroactive surface area of 1.21 …

Design And Validation Of A Multiple Axis, Passive 3d-Printed Ankle-Foot Prosthetic For Functional Gait, Brogan Rene Landeen

Dissertations and Theses

By 2050, an estimated 3.6 million individuals will be living with lower limb loss, with transtibial (below the knee) amputations being the most common type of lower limb surgery. Prosthetic devices are the standard of care for rehabilitating these amputees; each device is explicitly designed to enhance stability, energy storage and release, flexibility, and active propulsion. Prosthetic selection is based on user specifications, including activity level, comfort, and anthropometry. Despite the consensus that prosthetics help to restore impaired gait, traditional, commercial prosthetics fabricated with carbon fiber via injection molding are expensive and often require multiple modifications by a prosthetist before …

Magnetic Heating Efficiency Of Magnetite Nanoparticles: Dependence On Size And Alternating Magnetic Field, Sarah E. Kubican

Theses and Dissertations--Biomedical Engineering

Magnetic heating mediated by magnetic iron oxide nanoparticles (MION) has several clinical applications including cancer thermal therapy, tissue thawing for organ preservation, and magnetogenetics. However, current models of magnetic heating, including the widely used linear response theory, inadequately predict MION heating efficiency. An experimental study covering alternating magnetic field (AMF) strengths and frequencies ranging from 3.98 – 27.85 kA/m and 103.6 – 984.1 kHz, respectively, with a range of MION core diameters 9.5- 30.3 nm was conducted to elucidate the relationships between these AMF parameters and MION sizes and the resulting heating efficiencies. Heating efficiency was found to increase approximately …

Pathogen Surveillance Of Viruses And Antimicrobial Resistance Through Wastewater Based Epidemiology, William Strike

Theses and Dissertations--Biomedical Engineering

Pandemic surveillance is a cornerstone in public health safety, as it enables identification of pathogens circulating within a community before they become widespread outbreaks. Wastewater based epidemiology has blossomed in recent years due to its success in the SARS-CoV-2 pandemic, but this form of public health surveillance has a global equity problem. A large majority of the wastewater-based surveillance work has been done in large metropolitan cities with access to advanced testing infrastructure, which poses a challenge as we consider where pandemics have historically emerged. Therefore, there is a need to identify, adapt, and develop workflows to meet the needs …

Simplified Molecular Diagnostics Methods For Environmental Testing Of Pathogens And Other Applications, Mohammad Dehghan Banadaki

Theses and Dissertations--Mechanical and Aerospace Engineering

Environmental Surveillance (ES) has emerged as a powerful tool to monitor the emergence and persistence of a pathogen within a facility or community using wastewater/water analysis. Over the past four years, implementation of ES has experienced an explosive acceleration, driven by efforts to monitor the spread of SARS-CoV-2, which has made ES a routinely used public health tool in many locations. We can now use ES to measure the emergence/presence/abundance of different viruses (e.g., SARS-CoV-2, influenza, mpox), bacteria (e.g., E. coli, V. cholerae, antibiotic-resistant strains), fungi (e.g., C. auris), and other biological markers indicative of infectious diseases. However, its broad …

Direct Numerical Simulation Of Pulsating Flow In Curved Pipes: Insights Into Aortic Dissection In Humans, Gokul Anugrah Gopakumar

Theses and Dissertations--Mechanical and Aerospace Engineering

This dissertation investigates the hemodynamics of pulsating blood flow in curved vessels through direct numerical simulations (DNS), with the overarching aim of uncovering fluid dynamic mechanisms linked to the onset and progression of aortic dissection in humans. The work is structured in two parts: (i) fundamental studies in idealized geometries and (ii) preliminary investigations in patient-specific anatomies. In the first part, curved pipe models representing the aortic arch are used to isolate the effects of pulsation frequency, amplitude ratio, and curvature ratio on transitional and turbulent flow dynamics. The simulations reveal that curvature-driven centrifugal forces shift the peak velocity toward …

Influence Of Agrochemical Mixtures On Nitrogen Transformations In Floating Treatment Wetlands, Matthew Russell

Theses and Dissertations--Biosystems and Agricultural Engineering

Controlling losses of nitrate-N from agricultural fields to ground and surface water environments is one of the most pressing water resources problems today. Increasing levels of nitrate-N pollution in surface and groundwater is a critical threat to human and environmental health across the globe. To mediate nitrate-N losses, natural and constructed wetlands have been increasingly used as nutrient mitigation technologies and strategies. The use of wetlands as a treatment approach for nitrogen in runoff is a common practice in agroecosystems, however, nitrate-N is not the sole constituent present in agricultural runoff, and other biologically active contaminants have the potential to …

Integrated Compliant Structure For A Hand Exoskeleton, Tristan R. Koopman

Honors Undergraduate Theses

This thesis presents the design and prototyping of a wearable hand exoskeleton that integrates a flexible structural framework to assist with hand movement while maintaining comfort and anatomical conformity. The goal was to create a device that supports tendon-driven actuation through a compliant structure, combining elements of rigidity and flexibility to match the natural geometry and motion of the human hand. Traditional hand exoskeletons often trade off motion for structure or vice versa. This project aims to bridge that gap with a hybrid compliant design that balances flexibility and support. The design process followed an iterative approach involving rapid prototyping …

Fabricating Silver-Ceria Polymer Nanocomposite Scaffolds For Biomedical Therapeutic Applications, Shreya S. Pawar

Honors Undergraduate Theses

Improper healing of bone fractures and limited regeneration of bone following bone tumor resection remain a prevalent complication worldwide. Long-term effects of this include joint instability, limited movement, and arthritis. Bone infections (osteomyelitis), reactive oxygen species (ROS) generation via excessive inflammation, and underlying conditions such as osteoporosis can contribute to suboptimal bone tissue regeneration. ROS accumulation stimulates osteoblast apoptosis, while promoting osteoclast differentiation. These processes inhibit mineralization and osteogenesis. Conventional therapeutics involve the utilization of drugs and bone grafts. However, these approaches pose limitations and can result in subsequent complications. Microbial infections, ROS accumulation, and excessive inflammations are factors that …

Ultrasound Shear Wave Elastography: Development Of Tissue Models And Investigation Of Shear Wave Variability, Emily J. Miller

Dissertations, Master's Theses and Master's Reports

Ultrasound shear wave elastography (USWE) is an evolving and promising clinical tool for noninvasively measuring in vivo soft tissue biomechanical properties. Assumptions incorporated into the clinical workflow and technical limitations have created gaps between theoretical and clinically derived solutions. The heterogeneity of the fibrotic liver tissue, composition of the background, such as the presence of fatty liver tissue, and the preferred local orientation of the scarred fibrotic liver tissues embedded into the liver parenchyma, may contribute to the uncertainty in USWE measurements. This study aims to systematically investigate four cofounding factors (i.e., size, volume fraction, orientation of the fibrotic inclusions, …

Online Parameter Adaptation Of Lqr Controllers Via Rls For Prosthetic Joint Control: Experimental Validation On A Quanser Qube-Servo 2 Platform, Cynthia Lopez-Jordan

Theses and Dissertations

This thesis develops and experimentally validates an online adaptive Linear Quadratic Regulator (LQR) control method for prosthetic joint systems using Recursive Least Squares (RLS)-based real-time parameter estimation on the Quanser QUBE-Servo 2 platform. Traditional LQR controllers assume a fxed system model, which limits adaptability and results in reduced tracking accuracy, poor robustness, and loss of optimal performance when applied to dynamically changing prosthetic joints, infuenced by load variations, user gait changes, and mechanical wear. Limited experimental validation exists for combining RLS with online LQR adaptation in prosthetic-like systems.

To address these limitations, an RLS-driven Adaptive LQR framework was implemented to …

Design And Control Of A Stroke Therapy Device, Hugh Elliott

Open Access Master's Theses

Stroke is a leading cause of physical disability around the world, and the likelihood of stroke increases as people live longer. The current number of physiotherapists is insufficient to meet the increasing demand for their services. As a result, there has been a focus on developing robotic devices that function similarly to traditional therapy, enabling multiple patients to be seen simultaneously. While many devices have been created and tested, most are expensive, complex, and require trained personnel for supervision, thereby limiting their outreach. This thesis presents the design and control of a low-cost stroke therapy device designed to promote upper …

Emotion Processing In Adolescents With Epilepsy And Healthy Controls Using Multi-Modal Neuroimaging, Frances Kathryn E. King

Bioengineering Dissertations - Archive

Epilepsy is increasingly recognized as a disorder not only of seizures but also of widespread network dysfunction, impacting cognitive and emotional processing. One critical cognitive process affected in epilepsy is emotional conflict processing, which relies on the interplay of multiple brain networks. However, the spatiotemporal dynamics of emotional conflict processing in epilepsy, particularly in adolescents, have remained poorly understood. This dissertation investigated the neural mechanisms underlying emotional conflict processing in typically developing adolescents and adolescents with epilepsy using magnetoencephalography (MEG). The first study elucidated the spatiotemporal profile of emotional conflict processing in 24 typically developing adolescents using magnetoencephalography (MEG). Cluster-based …

Neurovascular Coupling Impairments In Acute Traumatic Brain Injury: An Eeg-Nirs Analysis, Zachary Armstrong

Bioengineering Theses - Archive

Traumatic brain injury (TBI) is a major cause of neurological impairment, often leading to variable recovery and uncertain prognosis in the neurocritical care setting. There is a pressing clinical need for robust, physiologically grounded biomarkers to inform prognosis and therapeutic decision-making in acute TBI. This thesis investigates neurovascular coupling (NVC), the physiological coordination between neuronal activity and cerebral blood flow, as a candidate biomarker for brain function and recovery after injury.

A prospective cohort study was performed using simultaneous electroencephalography (EEG) and near-infrared spectroscopy (NIRS) recordings in patients with moderate-to-severe TBI and healthy controls. Wavelet transform coherence (WTC) analysis was …

Learning From Leads: A 1d Dilated Resnet For Ecg Chagas Disease Screening, Somesh Saini, Matheus Lima Diniz Araujo

Student Scholarship

No abstract provided.

Electro-Vascular Dynamics During Auditory Processing: Variation Along The Schizotypy Continuum, John P. Mclinden

Open Access Dissertations

Electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) are complementary noninvasive neuroimaging modalities that have contributed greatly to our understanding of the mechanisms of auditory processing. As an emerging technology, fNIRS has produced promising insights into the mechanisms of auditory processing, although considerable work remains to characterize hemodynamic responses in auditory tasks. In addition, the complementary nature of EEG and fNIRS and the relationships between the signals they record have been underexplored. In particular, nonlinear interactions between these signals remain under-characterized, despite the potential benefit to future multimodal neuroimaging studies. A challenge in understanding these interactions is the influence of systemic …

Comparative Study Of Physiological Signals Between The Embraceplus And The Shimmer3 Gsr+, Cassidy Considine

Open Access Master's Theses

Understanding team dynamics and their physiological impact is essential across high-stakes industries such as healthcare, aviation, and defense. In stressful environments, optimizing team performance requires not only assessing communication but also monitoring physiological indicators of stress. Electrodermal activity (EDA) and heart rate variability (HRV) are commonly used to capture autonomic responses, offering insight into emotional arousal and cardiovascular regulation.

This pilot study compares a commercial wearable device, the EmbracePlus, with a research-grade device, the Shimmer3 GSR+, to evaluate differences in physiological signal acquisition. Twelve participants completed a five-phase experimental protocol while wearing both devices simultaneously on the non-dominant wrist/forearm. EDA …

Globus Pallidus Internus Dynamics During Freezing Of Gait, Nicholas Druck, Dean J. Krusienski, Josephine Wallner

Graduate Research Posters

Background: Parkinson’s disease (PD) is a progressive neurodegenerative disorder affecting ~1 in 1000 individuals over age 45. Freezing of Gait (FOG), a debilitating symptom in late-stage PD, affects up to 63% of patients and contributes to falls and reduced quality of life. While deep brain stimulation (DBS) of the subthalamic nucleus (STN) helps some symptoms, FOG remains difficult to treat. Given the complexity of basal ganglia circuitry, the role of related basal ganglia nuclei, such as the Globus Pallidus internus (GPi), in FOG deserves further investigation.

Methods: Five PD patients with FOG, implanted with Medtronic Percept DBS systems …

Flipped Classroom Versus Lecture: A Quasi-Experimental Study Evaluating The Performance Of Dental Students.”, Manal Elhijazi, Ihsane Benyahya

Health Sciences

Background: The flipped classroom is an active pedagogical modality that improves learning, autonomy and critical thinking. This work aims to evaluate the impact of the flipped classroom on student performance compared to the lecture in a biomaterials course.

Material and methods:Second-year dental students were invited to participate voluntarily in this quasi-experimental study .Thus, they were divided into two groups: one group benefited́ from the flipped classroom while the control group attended the lecture. At the end of a formative evaluation for both groups, their average grades were compared using Student's test (significance threshold set at p

Results : …

Enhanced Cholesterol Efflux And Atherosclerosis Regression Via Ceh Gene Delivery Using Galactose-Functionalized Dendrimeric Nanoparticles, Huari Kou, Jing Wang, Paul J. Yannie, Da Huang, William J. Korzun, Genta Kakiyama, Siddhartha S. Ghosh, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Cholesteryl ester hydrolase (CEH) is a critical enzyme in cholesterol ester hydrolysis, influencing cholesterol metabolism and efflux. This study demonstrates that CEH overexpression promotes free cholesterol efflux from macrophages, thereby reducing the lipid burden in existing atherosclerotic plaques. To enable targeted delivery, galactose-functionalized polyamidoamine (PAMAM) dendrimeric nanoparticles were utilized as nanocarriers for hepatic delivery of the CEH expression vector. The therapeutic potential of CEH plasmid-loaded dendrimeric nanoparticles was evaluated in Ldlr-/- mice. Results showed a significant reduction in total lesion area (21%) and aortic arch lesion area (23%) compared to baseline. Lesion component analysis revealed marked decreases in total cholesterol …

In Vitro Microfluidics System For Mechanobiologic Investigations, Michael A. Daanen

Honors Theses

Mechanobiology is an emerging field that aims to study the relationships between mechanical forces and cellular behavior. Such mechanobiological relationships are especially critical in the cardiovascular system, where endothelial cells lining the vasculature align in response to fluid shear stresses from blood flow (Sinha, 2016). Implanted flow devices, diabetes, chronic hypertension, and various other diseases and pathophysiologies alter vessel geometries and flow dynamics. Such alterations impact fluid shear stress and endothelial cell behavior, leading to microcirculatory dysfunction, vessel leakage, and organ failure (Poredos, 2021; Papadaki, 1999; Leitschuh, 1987). To simulate dysfunctional endothelial cell behavior in vitro and evaluate novel therapeutic …

Engineering Nanomaterials From Phase-Change Biological Materials Reacting With Carbon Dioxide, Qingyang Li

Graduate Theses, Dissertations, and Problem Reports (ETD)

The current global situation concerning CO2 emissions is increasingly alarming, with rising concentrations of CO2 significantly worsening climate change and global warming. Atmospheric CO2 levels are now at their highest in millions of years, driving a host of catastrophic effects, including but not limited to extreme weather events, rising sea levels, ocean acidification, disrupted ecosystems, deteriorating air quality, respiratory health issues, heat-related illnesses, threats to food and water security, and escalating social and geopolitical tensions. To keep global warming to no more than 1.5°C higher than that of pre-industry – as called for in the Paris Agreement – emissions need …

A Limb-Speed-Driven Locomotor Control System And Its Ability To Adapt, Emily Marie Herrick

Graduate Theses, Dissertations, and Problem Reports (ETD)

Despite how simple walking may seem, the locomotor control system is structurally and functionally complex. Its hierarchical organization of supraspinal and spinal networks with forward and feedback pathways has many interactions at multiple levels that are dependent on the dynamics of a high-dimensional musculoskeletal system. Having a comprehensive understanding of sensorimotor integration within a healthy locomotor control system is crucial for understanding changes to the system due to age or neurologic disease and developing effective technologies to recover mobility in those populations. In this dissertation, we address persistent gaps in knowledge pertaining to how the nervous system controls locomotion.

In …

Finite Element Modeling And Experimental Characterization Of Overmolded Gold-Palladium Composite Leads And Their Mechanical Behavior Under Cyclic Fatigue For Long-Term Implant Applications, Tanner Davis

Graduate Theses, Dissertations, and Problem Reports (ETD)

Auditory Nerve Interface (ANI) devices, currently in developmental stages, represent an emerging neuroprosthetic approach to restore hearing in severe sensorineural loss patients by directly stimulating the auditory nerve via the Utah Slanted Electrode Array (USEA). Conventional implant leads are comprised of multiple wires made from materials such as platinum-iridium and MP35N stainless steel that are overmolded in an insulative material. These materials are not possible to bond with to electrode array used in the ANI device, necessitating the evaluation of a new material like Au-Pd to ensure its functionality and durability under cyclic stresses. This gap necessitates characterization of alternative …

Delivery Method For Dissolvable Staples, Brian Nguyen, Colleen Kroah, Bethany Fogle, Sean Brown

Williams Honors College, Honors Research Projects

Surgical staples play a vital role in modern medicine by enabling efficient wound closure and tissue repair. However, traditional metal staples often require removal, increasing patient discomfort and the risk of infection. Dissolvable staples offer a promising alternative, eliminating the need for removal while maintaining secure wound closure. Despite their potential, current delivery systems for dissolvable staples face significant challenges, including inconsistent deployment, lack of precision, and inadequate integration with surgical workflows.

Developing an optimized delivery system is critical to maximizing the benefits of dissolvable staples. Such a system must ensure reliable performance, precision, and ease of use while maintaining …

Neurotensin Regulates Primate Ovulation Via Multiple Neurotensin Receptors, Andrew C. Pearson, Jessica S. Miller, Hannah J. Jensen, Ketan Shrestha, Thomas E. Curry Jr., Diane M. Duffy

Department of Biomedical and Translational Sciences Faculty Publications

Neurotensin (NTS), a small neuropeptide, was recently established as a key paracrine mediator of ovulation. NTS mRNA is highly expressed by granulosa cells in response to the luteinizing hormone (LH) surge, and multiple NTS receptors are expressed by cells of the ovulatory follicle. To identify the role of NTS receptors NTSR1 and SORT1 in ovulation in vivo, the dominant follicle of cynomolgus macaques (Macaca fascicularis) was injected with either vehicle control, the general NTS receptor antagonist SR142948, the NTSR1-selective antagonist SR48692, or the SORT1-selective antagonist AF38469. Human chorionic gonadotropin (hCG) was then administered to initiate ovulatory events. …

Effects Of Changes In Strouhal And Reynolds Numbers On Beetle Wing Aerodynamics, Keith L. Thiha

Honors Undergraduate Theses

Insect flight has long been a subject of interest across the scientific community, largely due to the exceptional aerodynamic performance insects demonstrate relative to their size. Insects tend to have very high aerodynamic performance characteristics like thrust and lift generation compared to their size. This has many potential applications in improving aircraft performance, however the flow phenomena concerning insect wing aerodynamics is still an area of ongoing research. This study aims to investigate how variations in key nondimensional flow parameters—specifically the Reynolds number and Strouhal number—affect the aerodynamic performance of beetle wings. Strouhal numbers ranging from 0.2 to 0.6 were …

Synthesis And Characterization Of Free Radical Scavenging Dendrimer Nanogels Via Cross-Linking Reaction-Enabled Flash Nanoprecipitation, Lin Qi, Da Huang, Huari Kou, Anna Chernatynskaya, Nuran Ercal, Hu Yang

Chemistry Faculty Research & Creative Works

This work reports the development and evaluation of dendrimer-based nanogels based on Poly amidoamine (PAMAM) dendrimer generation 5, engineered to act as a carrier with reactive oxygen species (ROS)-scavenging capabilities. We developed a cross-linking reaction-enabled flash nanoprecipitation method in which the cross-linking reaction occurs during the flash nanoprecipitation process to form a cross-linked nanostructure. Using this approach, an N-hydroxy succinimide (NHS)-functionalized ROS-responsive thioketal cross-linker (TK-NHS) was synthesized and utilized to cross-link DAB-core PAMAM dendrimer G5, resulting in the formation of G5-TK nanogels. The resulting nanogels were characterized using dynamic light scattering and transmission electron microscopy, and their cytocompatibility, irritancy, cellular …

The Pre-Polarization And Concentration Of Cells Near Micro-Electrodes Using Ac Electric Fields Enhances The Electrical Cell Lysis In A Sessile Drop, Kishor Kaphle, Dharmakeerthi Nawarathna

Electrical & Computer Engineering Faculty Publications

Cell lysis is the starting step of many biomedical assays. Electric field-based cell lysis is widely used in many applications, including point-of-care (POC) applications, because it provides an easy one-step solution. Many electric field-based lysis methods utilize micro-electrodes to apply short electric pulses across cells. Unfortunately, these cell lysis devices produce relatively low cell lysis efficiency as electric fields do not reach a significant portion of cells in the sample. Additionally, the utility of syringe pumps for flow cells in and out of the microfluidics channel causes cell loss and low throughput cell lysis. To address these critical issues, we …