Biomedical Engineering and Bioengineering Commons^™

Piezoelectric And Conductive Polymer Based Flexible Devices Enabling Cardiovascular Health Sensing And Energy Harvesting, Andrew Closson

Dartmouth College Ph.D Dissertations

Piezoelectric materials show great promise for low-power wearable and implantable sensing, but their rigidity makes it challenging to integrate them with biological tissue. To address this, researchers have started exploring polymer-based functional materials that offer flexibility and are suitable for interfacing with the human body. However, these materials are still in their early stages, and a framework is necessary to illustrate how these materials, in conjunction with novel fabrication techniques and device designs, can enable the development of multi-functional sensing and energy harvesting devices.

This thesis utilizes highly scalable fabrication methods for functional polymers to build and test a flexible …

Dual Color Optogenetic Control For Analyzing Cardiac Function In Drosophila, Jiantao Zhu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Prolonged consumption of carbohydrate-rich diets and immobile lifestyles frequently cause metabolic disorders and obesity and, as a result, may lead to progressive heart dysfunction among broad social groups of the population. Drosophila melanogaster serves as an essential model organism in cardiovascular disease research due to conserved physiological and genomic traits shared with humans, its genetic and molecular toolbox versatility, and cost-effective maintenance. Here, we combine optogenetics and optical coherence tomography to study cardiovascular function in D. melanogaster. A new optogenetic pacing system has been developed, employing a transgenic line carrying two opsins: ChR2 and NpHR2.0. A custom-built hardware setup …

Validity Of Fitbit And Garmin Devices While Ascending And Descending Flights Of Stairs, Alan Garcia

UNLV Theses, Dissertations, Professional Papers, and Capstones

Two popular wearable fitness device brands are Fitbit and Garmin. The validity of Fitbit and Garmin’s wrist-worn devices in measuring step counts in various settings, such as walking up and down a staircase, is unclear. PURPOSE: To determine if four devices, the Fitbit Charge 2, Fitbit Versa 2, Garmin Fēnix 5 and Garmin Vívosmart HR+ record valid measures of step count when ascending and descending flights of stairs at three different speeds. METHODS: Twenty-eight participants (n=28) were tested individually. Two devices were randomly selected to be placed on each wrist. Participants climbed up and then down one, two, and three …

The Biological Activity Of Dual-Responsive Glycopolymers For Intracellular Codelivery Of Antigen And Lipophilic Adjuvant, Micaela Shields

Honors Theses

Subunit vaccines present themselves as an attractive alternative to traditional approaches to vaccines, which utilizes whole organisms to trigger an immune response. While these traditional approaches have proven themselves reliable within the history of vaccinations, they generally deliver subpar robust cellular-mediated immunity and pose many safety risks. Composed of proteins and /or peptides, subunit vaccines are safer and more precise alternatives to traditional approaches. However, the pharmacokinetic properties of the macromolecules that make up these vaccines hinder the subunit vaccine’s level of immunogenicity [d1] Examples of this hindrance include but are not limited to aggregation at the injection site and …

Development Of Methods To Enhance Stem Cell Derived Islet Survival, Aining Fan

McKelvey School of Engineering Graduate Student Theses & Dissertations

No abstract provided.

Continuous Bioprocessing: Technology For Next-Generation Biopharmaceutical Manufacturing Development Of A Python-Coded Bench-Scale Raman-Based Continuous Bioprocess Platform, Christine Urrea

KGI Theses and Dissertations

Current industrial practices for producing biopharmaceuticals include fed-batch production with batch isolation and purification. Nonproductive hold-up steps and manual offline measurements are common in batch processing which increases processing time and contributes to a high cost of production. Current market trends and cost pressures in the biopharmaceutical industry are creating a push to innovate bioprocessing platforms. Continuous bioprocessing has been considered a solution to the current limitations of batch production of biopharmaceuticals. Continuous bioprocessing involves intensifying individual processing steps by eliminating hold-up steps through a continuous operation to increase productivity, which results in advantages such as lower capital and production …

The Development Of A Primer Payload With Microparticles For Uti Pathogen Identification Using Polythymidine- Modified Lamp Primers In Droplet Lamp, Jonas Otoo

KGI Theses and Dissertations

Nucleic acid amplification tests (NAATs) are among the diagnostic tests with the highest sensitivity and specificity. However, they are more complex to develop than other diagnostic tests such as biochemical tests and lateral flow immunoassay tests. Polymerase chain reaction (PCR) is the gold standard for NAATs. PCR requires thermal cycling to achieve clonal amplification of the target pathogen DNA for diagnosis. Thermal cycling poses a challenge in the development of PCR diagnostics for point-of-care (POC) settings. Loop-mediated isothermal amplification (LAMP) offers an isothermal method for NAATs diagnostics. The advancement of the microfluidics field significantly enhances the development of LAMP diagnostics …

Antimicrobial Activity And Mechanism Of Amyloid Proteins And Synthetic Conjugated Polyelectrolytes, Fahimeh Maghsoodi

Nanoscience and Microsystems ETDs

Although the exact cause of Alzheimer’s disease (AD) is still unknown, it is widely considered that the accumulation of amyloid plaques composed of the amyloid-β (Aβ) peptide in the brain is linked to neurodegeneration. Co-localization of viral DNA with Aβ plaques, the association of brain infection and AD, and research indicating the protective effect of Aβ against bacteria and fungi in mice and human cells have led to the hypothesis that Aβ expression and deposition may be central to its function as an antimicrobial peptide (AMP). In my thesis research, we seek to elucidate how Aβ functions as an AMP …

Understanding Vascular Calcification Through The Lens Of Canonical Wnt Signaling, Karlee Mcneel

Theses and Dissertations

Every 37 seconds, someone in the United States dies from cardiovascular disease. Vascular calcification is one of the underlying causes of these fatal events. Medial calcification develops following arteriosclerosis, or hardening of the arteries. Medial calcification is characterized by the deposition of hydroxyapatite in the medial layer of the arteries after normal vascular smooth muscle cells undergo a phenotypic switch to resemble osteoblast-like cells. It is hypothesized that this switch is caused by the wingless related (WNT)-Signaling pathway. The WNT-Signaling pathway, upon activation, causes the upregulation of osteogenic markers for the development of osteoblast-like cells. Current treatments alleviate consequences of …

The Antler: The Design And Development Of An Independent Shower Support Stand For Those Living With Lower Extremity Limb Loss, Kylie Wright

Honors Theses

While we do not often think about it, taking a shower is a privilege. Standing in the hot water, cleaning off after a long day outdoors, and taking a moment to simply relax is an experience that most people in the U.S. have participated in. However, about 1.4 million Americans do not have this luxury3. Lower extremity amputees have long been advised to shower while seated for their safety. This population is unable to experience the simple independence that accompanies standing in the shower. Despite the growing rate of amputations each year, no products are currently available on the market …

Soil Respiration Measurements Reveal High Retention Of Organic Carbon From Corn Residue Derived High-Lignin Fermentation Byproduct Enabling Sustainable Lignocellulosic Biofuel Production, Michelle Sun Wang

Dartmouth College Master’s Theses

While 2G biofuel production can utilize non-edible, lignocellulosic feedstocks such as agricultural residues to produce liquid fuel, harvesting crop residues is unsustainable without careful management of the soil underneath. By harvesting a fraction of the crop residues left in the field after harvest, soil health can diminish and critically, the soil organic carbon (SOC) stored in agricultural fields can decrease. Currently, in the most popular 2G process models published, the issue of soil degradation remains unresolved with residue harvest strategies receiving considerable attention in the literature and other SOC management strategies receiving far less. Specifically, the strategy of returning the …

Consolidated Chamber Design And Protocol For Olfactory Conditioning Assay With Drosophila Melanogaster, Sasha Bronovitskiy, Andres Castillo, Michael Yan, Fang Ju Lin

Journal of the South Carolina Academy of Science

The olfactory conditioning assay is widely used in Alzheimer’s disease research to quantify learning and memory in Drosophila melanogaster. The assay tests ability to recall an aversive conditioned stimulus of scent paired with electrical shock when presented a choice between shock-associated and unrelated scents. The T-maze, a commonly used apparatus for olfactory conditioning assays, employs an elevator mechanism to transfer live flies from the shock-delivering training chamber to the scent selection point. This elevator mechanism is known to cause fly casualty. T-mazes are not commercially available and often difficult to reproduce. Other existing variations of olfactory conditioning apparatuses use …

Balance Assessment Using A Smartwatch Inertial Measurement Unit With Principal Component Analysis For Anatomical Calibration, Benjamin M. Presley, Jeffrey C. Sklar, Scott J. Hazelwood, Britta Berg-Johansen, Stephen M. Klisch

Biomedical Engineering

Balance assessment, or posturography, tracks and prevents health complications for a variety of groups with balance impairment, including the elderly population and patients with traumatic brain injury. Wearables can revolutionize state-of-the-art posturography methods, which have recently shifted focus to clinical validation of strictly positioned inertial measurement units (IMUs) as replacements for force-plate systems. Yet, modern anatomical calibration (i.e., sensor-to-segment alignment) methods have not been utilized in inertial-based posturography studies. Functional calibration methods can replace the need for strict placement of inertial measurement units, which may be tedious or confusing for certain users. In this study, balance-related metrics from a smartwatch …

Multiple And Consecutive Genome Editing Using I-Gonad And Breeding Enrichment Facilitates The Production Of Genetically Modified Mice, Carolina R Melo-Silva, Cory J Knudson, Lingjuan Tang, Samita Kafle, Lauren E. Springer, Jihae Choi, Christopher M. Snyder, Yajing Wang, Sangwon V. Kim, Luis J. Sigal

Department of Microbiology and Immunology Faculty Papers

Genetically modified (GM) mice are essential tools in biomedical research. Traditional methods for generating GM mice are expensive and require specialized personnel and equipment. The use of clustered regularly interspaced short palindromic repeats (CRISPR) coupled with improved-Genome editing via Oviductal Nucleic Acids Delivery (i-GONAD) has highly increased the feasibility of producing GM mice in research laboratories. However, genetic modification in inbred mouse strains of interest such as C57BL/6 (B6) is still challenging because of their low fertility and embryo fragility. We have successfully generated multiple novel GM mouse strains in the B6 background while attempting to optimize i-GONAD. We found …

Growth Plate Cartilage: Understanding The Contribution Of Adhesion To Column Formation And Matrix Structure, Sydney E. Greer

Theses & Dissertations

Throughout fetal and adolescent development, bone growth is regulated by fine-tuned and controlled maturation of chondrocytes through a cartilaginous template called the growth plate. Bone growth rate is controlled through cell enlargement and extracellular matrix deposition, while the polarized arrangement of proliferative chondrocytes into columns aligned with the long axis of the bone potentiate growth. Chondrocytes are surrounded by a complex three-dimensional arrangement of matrix molecules, all of which are secreted by chondrocytes and assembled/remodeled to support the biological functions of the cell. Adhesion receptors found on the cell membrane of chondrocytes are crucial to the organization of matrix proteins …

To Hear Or Not To Hear: How “Best Interest” Determinations Can Help In The Cochlear Implant Debate, Tessa Wright

Minnesota Journal of Law, Science & Technology

No abstract provided.

Multichannel Modulation Of Depolarizing And Repolarizing Ion Currents Increases The Positive Rate-Dependent Action Potential Prolongation, Candido Cabo

Publications and Research

Prolongation of the action potential duration (APD) could prevent reentrant arrhythmias if prolongation occurs at the fast excitation rates of tachycardia with minimal prolongation at slow excitation rates (i.e., if prolongation is positive rate-dependent). APD prolongation by current anti-arrhythmic agents is either reverse (larger APD prolongation at slow rates than at fast rates) or neutral (similar APD prolongation at slow and fast rates), which may not result in an effective anti-arrhythmic action. In this report we show that, in computer models of the human ventricular action potential, the combined modulation of both depolarizing and repolarizing ion currents results in a …

The Future Is Now In Twisted Coil Polymer Actuators (Tcpa), Ryan Ronquillo

Electronic Theses and Dissertations

This thesis aimed to fabricate and test twisted coiled polymer actuators (TCPA) to understand the mechanical and thermal aspects of this artificial muscle fiber. The purpose of this thesis was to find a linear relationship using the LVDT sensor, fabricating TCPA fibers, and interpreting the data. The project tested whether nylon/polymer could be used as a better artificial muscle fiber.

This research accomplished three goals: (1) designing and fabricating a system capable of creating supercoiled muscle fibers consistently, (2) calibrating the Linear Variable Differential Transformer (LVDT) and Core, and (3) analyzing/interpreting the data of the Twisted Coiled Polymer Actuators (TCPA) …

Breast Tissue Tumor Detection Using Microstrip Patch Antenna With Defected Ground Structure, Nihal F. F. Areed, Hamdi Ahmed El Mikati, Laila T. Rakha

Mansoura Engineering Journal

This work proposes a slotted microstrip patch antenna with an inset feed and defective ground structure (DGS). The proposed antenna is built with Roger-RT/5880 (Ԑr=2.2) as the substrate material for X-band application with a resonant frequency of 10 GHz. The proposed design has been simulated using Finite Element Method (FEM) and the results of bandwidth and gain read about 700MHz and 8dB; respectively. The suggested design is compared with previously published equivalent designs in light of the most recent research. The comparison reveal that that the suggested design with tuned dimensions offers higher gain and wider bandwidth than what has …

Redesigning Nasogastric Feeding Tubes To Prevent Dislodgement, Shelby Lynn Berry, Sydney Ruth Rester

Honors Theses

Seniors at the University of Mississippi studying biomedical engineering complete a senior project that seeks to solve a problem in healthcare. Our team, composed of Sydney Rester, Shelby Berry, Andrew Ulmer, and Alex Bromley, sought to improve care associated with nasogastric feeding tubes. We identified two major problems: clogging and tube dislodgement. To address the problem of dislodgement, the team crafted a new feeding tube design with a balloon attachment. The attachment prevents a patient from pulling the feeding tube out and keeps the tube from dislodging due to normal patient movement. We further determined that our tube should be …