Biomedical Engineering and Bioengineering Commons^™

Design And Testing Of A Prototype Prosthesis For Pediatric Upper-Limb Transradial Amputees To Provide Adjustable Size And Modular Characteristics, Paul Heli

Master's Theses

This study was conducted to develop a financially accessible body-powered upper-limb prosthetic socket that can be adjusted to maintain fit and function for a growing child with a transradial amputation. The main objectives of the study were to design, manufacture, and test a device that was comfortable, functional, affordable, and adjustable. The socket was designed to be comfortable using global variables controlling the computer-aided design (CAD) model size with user-specific measurements. Comfort was also incorporated using shape-forming of the socket for specific residual limb features. The device was designed to perform the two main functions of suspension, or attachment to …

Development Of A Pressure Sensing System Coupled With Deployable Machine Learning Models For Assessing Residual Limb Fit In Lower Limb Prosthetics, Maxwell D. Lewter

Master's Theses

Lower limb amputations pose significant challenges for patients, with over 150,000 cases annually in the U.S., leading to a high demand for effective prosthetics. However, only 43% of lower limb prosthetic users report satisfaction, primarily due to issues with socket fit, which is critical for comfort, stability, and preventing injury. This study presents a deployable sensing system for potentially real-time monitoring of prosthetic socket fit by using pressure sensors and convolutional neural networks (CNNs) to analyze the pressure distribution within the socket. A novel CNN architecture, utilizing both dilated and strided convolutions, is proposed to effectively capture spatial-temporal patterns in …

Assessing Reproducibility Challenges In Clinical Metabolics, Darcy Lin Cochran

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

Current metabolomics research is expanding to be multiplatform and interdisciplinary. Metabolomic analysis has the potential to provide detailed insight into any biological system of interest to analyze the underlying molecular mechanisms of variables like environment, disease, and genetics. Human clinical metabolomics is a major research area that is often focused on finding biomarkers or panels of biomarkers for different diseases. However, results are difficult to compare across different laboratories since the field of metabolomics has yet to widely adopt best practices for sample preparation, data acquisition and data processing, results are difficult to compare across different laboratories.

This thesis focuses …

Synthesis And Process Optimization Of Cellulose Nanocrystals From Miscanthus X. Giganteus For Commercial Viability, Jaspreet Kaur

Graduate Theses and Dissertations

Cellulose nanocrystals (CNCs), derivatives of an abundant biopolymer, i.e., cellulose, are emerging as promising alternatives to petrochemical-based products due to their unique properties, including biodegradability, low toxicity, high strength, low density, large surface area and low coefficient of expansion. CNCs have diverse applications ranging from food packaging and textiles to drug delivery and medical implants, etc. Despite their potential, the widespread commercialization of CNCs faces significant hurdles owing to the high environmental burden and production costs. They are mainly driven by the commonly used source utilized for CNC synthesis i.e., wood and the intensive synthesis process i.e., requirement of …

Surgical Suturing Skill Assessment Using Estimated Hand Roll Angle From A Deep-Learning Computer Vision Algorithm, Jianxin Gao, Amir Mehdi Shayan, Simar P. Singh, Joe Bible, Ravikiran Singapogu, Richard E. Groff

Publications

This paper proposes a deep-learning computer vision algorithm to estimate hand roll angles for metric-based assessment of surgical suturing skills. The number of rolls metric, previously calculated directly from IMU data, counts the number of hand roll reversals during a single suture. To calculate this metric using computer vision, we apply a deep-learning algorithm that can reliably estimate hand roll angles after training on suturing videos collected on the SutureCoach simulator. Results show that the estimation accuracy of the deep-learning algorithm is robust to different video backgrounds. The number of rolls metrics were used to analyze suturing performance in the …

Mechanically Cost-Effective Approach For Bipedal Walking In Robots Using Instantaneous Collision Angle, Smit R. Patel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Humans, as bipedal locomotors, are effective at reducing the mechanical cost of transport (CoTmech) by adopting movement strategies and gaits that minimize energy expenditure for a given distance. By using different gaits at different speeds, leveraging their long spring-like tendons and muscle elasticity which store and release energy during movement, humans reduce the mechanical effort required for locomotion. Current locomotion solutions offered in bipedal robots, based on legacy walking and running gait models, are not great at energy efficiency unless walking at very low speeds. Additionally, the control system of robots, designed to ensure stability and adaptability, requires substantial resources, …

Eigenbin Compression For Reducing Photon-Counting Ct Data Size, Taly Gilat Schmidt, Zhye Yin, Jingwu Yao, Jiahua Fan

Biomedical Engineering Faculty Research and Publications

Background

Photon-counting CT (PCCT) systems acquire multiple spectral measurements at high spatial resolution, providing numerous image quality benefits while also increasing the amount of data that must be transferred through the gantry slip ring.

Purpose

This study proposes a lossy method to compress photon-counting CT data using eigenvector analysis, with the goal of providing image quality sufficient for applications that require a rapid initial reconstruction, such as to confirm anatomical coverage, scan quality, and to support automated advanced applications. The eigenbin compression method was experimentally evaluated on a clinical silicon PCCT prototype system.

Methods

The proposed eigenbin method performs principal …

Multimodal Spectroscopy To Study Tumor Microenvironmental Changes In Vivo, April Mordi

Graduate Theses and Dissertations

Every year there are millions of new cancer diagnoses and deaths worldwide. While great strides have been made in technologies and drugs for cancer treatment, there is still a need to understand tumor response to therapy as many patients still endure treatment failure after completing their treatment regimen. Current clinical imaging techniques for detecting response to therapy are utilized weeks to months after the course of treatment, and present limitations to measuring response during treatment. Optical spectroscopy techniques can help meet this need to determine the response of tumors to treatment as it allows for near real-time in vivo characterization …

The Clot Thickens: Investigation Of The Mechanism Behind Hypercoagulation In Covid-19 Patients, Toni Warnick

All Dissertations

Since its emergence in 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been associated with cardiovascular complications, which correlate with illness severity and increased mortality. It was initially thought that this hypercoagulable state was induced by endothelial dysfunction or cytokine storm because of SARS-CoV-2 infection. Although platelets have been reported to express the SARS-CoV-2 primary target receptor, angiotensin-converting enzyme 2 (ACE2), this remains controversial due to conflicting findings that suggest minimal to no ACE2 expression on platelets. This ambiguity has led to exploring alternative entry pathways, notably via the virus’s RGD (arginine-glycine-aspartic acid) sequence within its spike protein receptor-binding …

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

All Dissertations

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 …

Optimization Of Polymeric Micelles As A Delivery System For Crispr/Cas9 Ribonucleoprotein, Lucian Williams

All Dissertations

Clustered regularly interspaced short palindromic repeats (CRISPR) is an adaptive immune system in bacteria that has been harnessed to perform precise genetic modifications in mammalian cells. Among CRISPR-associated (Cas) proteins, Cas9 has emerged as a transformative tool in gene editing due to its simplicity, high specificity, and versatility compared to the other Cas proteins and gene-editing technologies. Despite its potential to cure genetic disorders, the clinical application of Cas9 has been hindered by challenges such as immunogenicity, off-target effects, and low delivery efficiency. To address these issues, this dissertation explores using polymeric nanoparticle systems to encapsulate and protect Cas9 and …

Multifunctional Peptides To Improve Nucleic Acid Delivery For Ovarian Cancer Treatment, Kharimat Lora Alatise

All Dissertations

RNA interference (RNAi) therapies, such as small interfering RNA (siRNA), offer a high-precision approach to reducing the expression of disease-promoting genes with minimal off-target effects. For aggressive diseases like ovarian cancer, RNAi therapy can serve as a robust treatment modality if delivered successfully. Over 70% of ovarian cancer patients are diagnosed in stages three and four, where the disease becomes more difficult to treat. High relapse rates and drug resistance in these stages demonstrate the need for novel strategies to sensitize tumors to chemotherapy, making siRNA a promising avenue for targeting resistance-associated oncogenes.

However, the delivery of siRNA remains a …

Investigating The Role Of Cd44 In Her2+ Breast Cancer Cells During Cancer Cell Redirection, Holly Caroline Jordan Campbell

All Dissertations

Despite a rise in survival rates of breast cancer patients due to advances in modern medicine, breast cancer is the most common type of cancer in women and is the second leading cause of cancer death in the United States. Early detection and a more personalized treatment of breast cancer has slowly improved patient outcomes. Nevertheless, there are impediments to better patient outcomes due to the complexity of the disease physiology. Therefore, there is a demand for a comprehensive understanding of cancer development as well as a need to understand tumor progression for enhanced therapies for patients.

Previous in vivo …

Characterizing Locust Anemotaxis: The Impact Of Sensory Perturbations On Flight Behavior, Yi-Xiao Huang

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis investigates the effects of sensory perturbations on locust flight behavior, with the goal of better understanding how locusts integrate multiple sensory inputs to maintain flight control. Through a series of experiments, locusts were subjected to visual impairment, turbulent wind conditions, mechanical impairments of their wings and antennae, and pheromonal interference. These perturbations allowed for the exploration of the contributions each sensory pathway makes to flight stability and navigation in a controlled environment.

Results show that while visual impairment does not significantly impact average flight speed, it increases variability in flight stability, suggesting that visual cues are important for …

Feasibility Study On Microwave Glucose Level Monitoring, Ricardo Cepeda

Theses and Dissertations

Diabetes management heavily relies on regular blood glucose monitoring, which traditionally involves invasive techniques. In recent years, significant research has been directed towards developing non-invasive glucose monitoring methods, particularly using electromagnetic waves. This study explores the feasibility of detecting blood glucose levels non-invasively by measuring the resonant frequency shifts of an antenna, influenced by the dielectric properties of blood. Microwave measurement techniques have garnered attention due to their ability to safely penetrate human tissue and detect biochemical markers like glucose. While previous studies have established a link between glucose concentration and dielectric properties, many techniques suffer from poor sensitivity or …

Type Ii Innate Lymphoid Cell Plasticity Contributes To Impaired Reconstitution After Allogeneic Hematopoietic Stem Cell Transplantation, Sonia J. Laurie, Joseph P. Foster, Danny W. Bruce, Hemamalini Bommiasamy, Oleg V. Kolupaev, Mostafa Yazdimamaghani, Samantha G. Pattenden, Nelson J. Chao, Stefanie Sarantopoulos, Joel S. Parker, Ian J. Davis, Jonathan S. Serody

Chemical and Biochemical Engineering Faculty Research & Creative Works

Type II innate lymphoid cells (ILC2s) maintain homeostasis and barrier integrity in mucosal tissues. In both mice and humans, ILC2s poorly reconstitute after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Determining the mechanisms involved in their impaired reconstitution could improve transplant outcomes. By integrating single-cell chromatin and transcriptomic analyses of transplanted ILC2s, we identify a previously unreported population of converted ILC1-like cells in the mouse small intestine post-transplant. Exposure of ILC2s to proinflammatory cytokines resulted in a mixed ILC1-ILC2 phenotype but was able to convert only a small population of ILC2s to ILC1s, which were found post-transplant. Whereas ILC2s protected against …

Two-Photon Imaging For Characterizing Tumor Microenvironmental Changes In Non-Small Cell Lung Cancer Associated With Metastatic Recurrence, Paola Monterroso Diaz

Graduate Theses and Dissertations

Lung cancer remains the leading cause of cancer deaths, comprising nearly 25% of all cancer deaths (Sung et al., 2021a). The five-year survival rate of patients with non-small cell lung carcinoma (NSCLC) remains significantly low given that over half present with locally advanced or metastatic disease at time of diagnosis, and experience tumor recurrence following therapeutic intervention (Tamura et al., 2015; Uramoto & Tanaka, 2014). Current evaluation techniques to assess treatment response are lacking, given they are implemented several weeks after treatment completion and are solely based on anatomical changes in tumor size, forgoing other criteria such as functional or …

Study Of Temperature Effects Of Glucose And Microwave Dielectric Dispersion Model, Ethan Grant Boone

Theses and Dissertations

In this study, the temperature effect of dielectric properties in various aqueous solutions containing glucose are examined. A design for a new testing chamber is introduced to provide improved conditions for testing to ensure accurate and precise measurements. A N-SMA Adaptor is used when obtaining dielectric characteristics of glucose solutions ranging 100-300mg/dl. Dielectric parameters are obtained adopting a modified Debye dispersion model. MATLAB is used to confirm coaxial dimensions are suitable fabrication designs using fixed dielectric parameters of air and water. Simulations and design models were implemented utilizing ANSYS High Frequency Structure Simulator and 3-D Modeler software to develop the …

3d Bioprinted Coaxial Tubule Optimization For Human Aortic Endothelial Cell Growth, Ilse Gabriela Perez Garcia

Theses and Dissertations

This paper introduces a research study of printing parameter optimization of extruded, cell-laden, 3D bioprinted coaxial tubules, as well as cell interaction observations. Optimization of printing parameters seeks to reduce variability of the tubules’ inner and outer diameters. The tubules were manufactured from a 0.4% Collagen I - 1.6% NaC6H7O6 (Sodium Alginate) bioink, that reaches gelation through interaction with a 3.2% CaCl2 (Calcium Chloride) solution. The bioinks were extruded through a dual syringe pump mechanism connected to a coaxial nozzle, which is mounted on an adapted 3D FDM (Fused Deposition …

Physicochemical Property Effects On Immune Modulating Polymeric Nanoparticles: Potential Applications In Spinal Cord Injury, Daniel J. Kolpek, Jaechang Kim, Hisham Mohammed, John C. Gensel, Jonghyuck Park

Markey Cancer Center Faculty Publications

Nanoparticles (NPs) offer promising potential as therapeutic agents for inflammation-related diseases, owing to their capabilities in drug delivery and immune modulation. In preclinical studies focusing on spinal cord injury (SCI), polymeric NPs have demonstrated the ability to reprogram innate immune cells. This reprogramming results in redirecting immune cells away from the injury site, downregulating pro-inflammatory signaling, and promoting a regenerative environment post-injury. However, to fully understand the mechanisms driving these effects and maximize therapeutic efficacy, it is crucial to assess NP interactions with innate immune cells. This review examines how the physicochemical properties of polymeric NPs influence their modulation of …