Digital Commons Network^™

Comparison Of Autonomic Control Of Blood Pressure During Standing And Artificial Gravity Induced Via Short-Arm Human Centrifuge, Ajay K. Verma, Da Xu, Michelle Bruner, Amanmeet Garg, Nandu Goswami, Andrew P. Blaber, Kouhyar Tavakolian

Electrical Engineering Faculty Publications

Autonomic control of blood pressure is essential toward maintenance of cerebral perfusion during standing, failure of which could lead to fainting. Long-term exposure to microgravity deteriorates autonomic control of blood pressure. Consequently, astronauts experience orthostatic intolerance on their return to gravitational environment. Ground-based studies suggest sporadic training in artificial hypergravity can mitigate spaceflight deconditioning. In this regard, short-arm human centrifuge (SAHC), capable of creating artificial hypergravity of different g-loads, provides an auspicious training tool. Here, we compare autonomic control of blood pressure during centrifugation creating 1-g and 2-g at feet with standing in natural gravity. Continuous blood pressure was acquired …

Reimagining Icarus: Ethics, Law And Policy Considerations For Commercial Human Spaceflight, Sara M. Langston

Publications

Commercial human spaceflight presents an area for engaging novel human activity and objectives, to include space exploration, entertainment, transportation and extraterrestrial resource acquisition. The inherent dangers and lack of scientific and medical certainty involved however raise interrelated questions of ethics, bioethics, law and public policy. This is particularly the case with spaceflight participant (SFP) screening, selection, and commercial human spaceflight activities where regulations are currently silent or lacking. In the absence of established law, ethics can play an important role by informing industry standards, policies and best practices. Understanding the fundamental ethical values at stake in the application of new …

Chronic Nerve Interfacing Utilizing Graft-Embedded Regenerative Macro-Sieve Electrodes, Amrita Nishtala

McKelvey School of Engineering Graduate Student Theses & Dissertations

Custom-designed macro-sieve electrodes represent a novel means of facilitating chronic high specificity nerve stimulation needed to control distal nerve musculature and restore sensorimotor function. Implantation of these electrodes requires the transection of the nerve, which has shown to disrupt muscle fiber distribution. This present study assesses the feasibility of implementing these electrodes in an end-to-side nerve graft. The macro-sieve electrodes were fabricated and micro-surgically implanted into 3.2 cm nerve autografts harvested from the sciatic nerve of 12 male Lewis rats. Electrode-enabled nerve grafts were micro-surgically implanted in an end-to-side manner into donor rat sciatic nerves without the need for a …

Nanostructured Materials Derived From Metal-Organic Frameworks For Energy And Environmental Applications, Zhiqiang Xie

LSU Doctoral Dissertations

Nowadays, energy and environmental issues have become the top priority among a series of global issues. Fossil fuels as the dominant source are depleted fast and usually lead to some environmental problems. Heavy metal pollution has posed a severe threat to environment and public health. Metal-organic frameworks (MOFs), as a very promising category of porous materials, have attracted more and more interest in research communities due to their extremely high surface areas, diverse nanostructures and unique properties. To meet the ever-increasing energy demand and tackle the heavy metal pollution in water, MOFs can function as ideal templates to prepare various …

Tumor-Targeted Double Emulsions For Ultrasound-Triggered Delivery Of Molecular Therapeutics., Connor S Centner

Electronic Theses and Dissertations

Cancer is the second leading cause of death in the United States, with 1.74 million new cancer cases diagnosed and 610,000 cancer deaths expected in 2018 alone. Current treatments often result in negative systemic effects and ineffective treatment of the tumor. Drug delivery vehicles have been developed for more effective local delivery methods, but many drug delivery vehicles lack spatial and temporal control. Targeted double emulsions are a new class of drug delivery vehicles which present a promising option for a high payload and controlled delivery. The purpose of our project was to develop and characterize an aptamer-chelated double emulsion …

Hybrid Brain-Computer Interface: A Novel Method On The Integration Of Eeg And Semg Signal For Active Prosthetic Control, Reza Darmakusuma, Ary Setijadi Prihatmanto, Adi Indrayanto, Tati Latifah Mengko

Makara Journal of Technology

This paper describes a novel method for controlling active prosthetics by integrating surface electromyography (sEMG) and electroencephalograph signals to improve its intuitiveness. This paper also compares the new method (RTA-2) with other existing methods (AND and OR) for controlling active prosthetics. Based on analysis, RTA-2 features higher true positive rate (TPR) and balanced accuracy (BA) than AND method. On the other hand, the new method (RTA-2) yields lower false detection rate (FPR) than OR method. Analysis also shows that RTA-2 possesses equal TPR, FPR, and BA with the detection of movement intention using sEMG-based system. Although the RTA-2 method shows …

Human Optimization And Performance Enhancement In Flight Via Real-Time Biofeedback (Project Have Hope), Michael S. Fritts

Theses and Dissertations

A four-phase, chronological, and build-up approach was implemented that commenced with basic hardware testing in a centrifuge and culminated in flights augmented by real-time biofeedback displays. A prototype Portable Electrocardiogram Unit (PECGU) was designed and proven to accurately measure heart rate (HR) and display percent heart rate reserve (%HRR). Results showed that %HRR was not a sole predictor of cognitive state. Cognitive responses indicated some correlation with %HRR, but were influenced by environment (centrifuge vs. flight). Subjective perceived exertion levels did not show statistically significant changes during test with biofeedback. A G-tracking task was evaluated during centrifuge and flight tests. …

Differentiating Human Populations Based On K-Mer Classification Of Hand Bacteria, Thrisha Doppala

Graduate Theses, Dissertations, and Problem Reports (ETD)

Bacterial communities found in and on the human body are not only used in studying human health conditions but are also effective in differentiating individuals due to their distinct profiles. Human palm regions harbor relatively more diverse bacterial communities and are indicative of population groups, life styles, geographic locations, age groups and health conditions. Sequences extracted from hypervariable region V3 of the 16S rRNA bacterial gene of hand bacterial samples from 9 different population groups were classified into Operational Taxonomic Units (OTU) with GreenGenes reference taxonomy using RDP (Ribosomal Database Project) classifier. Frequencies of identified OTUs were used to study …

Centrifugal Microfluidics For Label-Free Isolation Of Leukocytes Subpopulations From Whole Blood, Yuxi Sun

All ETDs from UAB

Leukocytes carry critical information regarding the immediate immune and inflammation status of the patients. Analysis of leukocytes requires isolation from blood since the leukocytes only consist <1% of all blood cells. Commonly used isolation processes exploit physical or biochemical differences between different cell types to enable separations. Current isolation methods inevitably subject cells to physical or biochemical stress that can activate leukocytes and change their natural state. Thus, information contained within isolated leukocytes is a combination of the natural state of the cell and an artifact of the isolation process. Microfluidics which takes advantage of scaling effects within microscale structures can ensure rapid and gentle alternatives to conventional isolation methods and is ideal for sorting, and analysis of cells and particles. The precise control of flow/particles and scaling effects of microfluidics have been applied for blood cells sorting and isolation. However, the limited processing capability and throughput as well as complex fabrication and operations have hampered widespread adoption of these approaches for replacement of conventional methods. My goal was to develop a simple yet powerful microfluidic tool that enables rapid separation of leukocytes while ensuring sufficient throughput, and minimizing isolation process induced activation without the need any sample pre-processing. This project is divided into two specific aims: i) to miniaturize the conventional density gradient centrifugation using centrifugal microfluidics for PBMC isolation and evaluate separation efficiency and activation status of isolated cells in comparison to conventional techniques; ii) develop new approach for PBMC sorting using microfluidic phase partitioning to enable separation of cells based on differences in cell surface energy. For specific aim 1, PBMCs were isolated based on differences in densities using microfluidic density gradient centrifugation. We show that PBMCs can be isolated from 100µl whole blood within 5 minutes. Evaluation of leukocyte activation via profiling of expression of surface integrins and chemokine receptors shows that our microfluidic approach significantly reduced PBMC activation in comparison to conventional isolation approaches. In specific aim 2, we sought to isolate cells based on differenced in surface energy using two-phase partitioning of dextran (DEX) and polyethylene glycol (PEG). Proof of concept demonstrations was accomplished using with polystyrene and silicon dioxide microbeads which represent a mixture of white blood cells and red blood cells. The DEX and PEG mixtures were introduced into a circular channel and phase separated under centrifugal force into unique DEX and PEG phases. The bead mixture was isolated via differences in their affinity to the two phases.

Biom 3110: Medical Physiology (Syllabus), Bradford D. Pendley

Biomedical Engineering Syllabi Archive

Course Description: Basic principles of human physiology and how these are applied in medicine and biomedical engineering problem and devices; physiological principles using appropriate mathematical and engineering models to construct an understanding of how the body works as an integrated system.

Modeling Of Realistic Heart Electrical Excitation Based On Dti Scans And Modified Reaction Diffusion Equation, Ihab Elaff

Turkish Journal of Electrical Engineering and Computer Sciences

A new method is proposed for modeling realistic heart activation using diffusion tensor imaging (DTI) scans based on biological properties of its tissues in addition to the working methodology of the DTI scanner. Modeling of the excitation propagation inside the heart is initiated by applying activation at only one pacing site at the root of the conduction network. The excitation propagation has been accomplished based on a proposed conduction system that is extracted from DTI heart scans and a modified version of monodomain reaction diffusion equation (RDE) that considers the heart inhomogeneous--anisotropic material. The Aliev--Panfilov method was used to model …

Inhibition Of Blood Coagulation Factor Xii: Evaluation Of Flavonoids As A Drug Candidate, Betsy Crosswhite

Honors Theses

This study investigated natural product inhibitors of blood coagulation Factor XII (FXII). FXII initiates the Kallikrein Kinin-System (KKS) within the intrinsic coagulation pathway. Increased expression of this system leads to proinflammatory and procoagulant activities. Inflammation occurs through downstream activation in the KKS. Following the activation of FXII-dependent pathway, bradykinin (BK) binds to the BK receptor 2 (B2) and produces inflammatory signaling. Abnormally increased BK can result in life threatening Hereditary Angioedema (HAE), characterized by severe reoccurring swelling. FXII is critical for pathogenic thrombosis, but is dispensable for hemostasis. This unique property of FXII makes it an attractive drug target. We …

Formulation Of Nanoparticle Systems For Drug Delivery Application In Biomedical Sciences, Victor Alfredo Rodriguez

Open Access Theses & Dissertations

Antibiotic-resistant strains of bacteria may result in serious infections which are difficult to treat. In addition, the poor antibiotic pipeline has also contributed to the crisis. Recently, the complex of furosemide and silver (Ag-FSE) has been reported as a potential antibacterial agent. However, its poor aqueous solubility is limiting its activity as an effective antibacterial agent. The purpose of this study was to encapsulate Ag-FSE into chitosan nanoparticles (CSNPs) and evaluate antibacterial efficacy. Ag-FSE CSNPs were prepared using ionic gelation technique. The particle size, polydispersity index and zeta potential of Ag-FSE CSNPs were determined using dynamic light scattering (DLS) technique. …

Fluid Flow In A Krogh Cylinder: A Model For A Single Capillary And Surrounding Tissue, Xianjie Qiu

Masters Theses

"A model describing the flow of plasma from the capillaries to the interstitial space in the extravascular tissue and back into the capillaries is constructed and solved. The flow through the tissue or the interstitial spaces is described by the Brinkman equation for porous medium, modified to account for the presence of cells considered as spheres. The flow of blood through the capillaries is considered to be that of a Newtonian fluid. The flow between capillary and tissue is coupled by the permeability of the capillary wall. The nature of flow and its magnitude was found to be highly dependent …

Computational Modeling For Abnormal Brain Tissue Segmentation, Brain Tumor Tracking, And Grading, Syed Mohammad Shamin Reza

Electrical & Computer Engineering Theses & Dissertations

This dissertation proposes novel texture feature-based computational models for quantitative analysis of abnormal tissues in two neurological disorders: brain tumor and stroke. Brain tumors are the cells with uncontrolled growth in the brain tissues and one of the major causes of death due to cancer. On the other hand, brain strokes occur due to the sudden interruption of the blood supply which damages the normal brain tissues and frequently causes death or persistent disability. Clinical management of these brain tumors and stroke lesions critically depends on robust quantitative analysis using different imaging modalities including Magnetic Resonance (MR) and Digital Pathology …

Visual Detection Of Small Unmanned Aircraft: Modeling The Limits Of Human Pilots, Gregory Stephen Woo

Doctoral Dissertations and Master's Theses

The purpose of this study was to determine the key physical variables for visual detection of small, Unmanned Aircraft Systems (UAS), and to learn how these variables influence the ability of human pilots, in manned-aircraft operating between 60-knots to 160-knots in the airport terminal area, to see these small, unmanned aircraft in time to avoid a collision. The study also produced a set of probability curves for various operating scenarios, depicting the likelihood of visually detecting a small, unmanned aircraft in time to avoid colliding with it. The study used the known limits of human visual acuity, based on the …

Visualization Of The Cardiac Excitation And Pvc Arrhythmia On A 3d Heart Model, Pranav Sreedharan Veliyara

Masters Theses

Visualization of the cardiac potential movement is important in understanding the physiology of the human heart. A 3D visualization tool will help the cardiology students and others interested in human physiology to understand the functioning of the heart. In this thesis, such a tool is proposed which helps in the visualization of the cardiac potential movement and Premature Ventricular Contraction (PVC) event on a 3D heart model. The cardiac excitation obtained from a limb lead and a precordial lead of a 12 lead electrocardiograph (ECG) is mapped on a 3D heart model with fixed conduction pathways. The 3D heart model …

Conference Program, Wilfred Chen, Nicole Borth, Stefanos Grammatikos

Biochemical and Molecular Engineering XX

No abstract provided.

An Ergonomics Investigation Of The Application Of Virtual Reality On Training For A Precision Task, Delaney M. Bales

Master's Theses

Virtual reality is rapidly expanding its capabilities and accessibility to consumers. The application of virtual reality in training for precision tasks has been limited to specialized equipment such as a haptic glove or a haptic stylus, but not studied for handheld controllers in consumer-grade systems such as the HTC Vive. A straight-line precision steadiness task was adopted in virtual reality to emulate basic linear movements in industrial operations and disability rehabilitation. This study collected the total time and the error time for the straight-line task in both virtual reality and a physical control experiment for 48 participants. The task was …

Supplemental Vibrotactile Feedback Control Of Stabilization And Reaching Actions Of The Arm Using Limb State And Position Error Encodings, Alexis Krueger, Psiche Giannoni, Valay Shah, Maura Casadio, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Deficits of kinesthesia (limb position and movement sensation) commonly limit sensorimotor function and its recovery after neuromotor injury. Sensory substitution technologies providing synthetic kinesthetic feedback might re-establish or enhance closed-loop control of goal-directed behaviors in people with impaired kinesthesia.

Battery Centric Serial Hybrid Aircraft Performance And Design Space, Lenny Gartenberg

Doctoral Dissertations and Master's Theses

The design space and flight envelope of a battery centric serial hybrid aircraft has been analytically derived. The formulation assumes cruising flight only and all energy available is used. The flight envelope can be generated for any conventional propeller driven serial hybrid aircraft. The advantageous combination of an electric motor and controllable-pitch electric propeller was also explored. The results are used to be able to control efficiency and noise at constant thrust and therefore constant airspeed. Manufacturer provided electric motor and propeller data is used for efficiency purposes. Since the electric motor is virtually silent compared to the propeller, published …

The Issues And Complexities Surrounding The Future Of Long Duration Spaceflight, Solomon Miiro

Graduate Student Works

The Comprehensive Exam put forward by this proposal is intended to address the learning objectives covered by the Master of Aeronautical Science Degree with specializations in Aviation Aerospace Safety Systems and some limited aspects in Human Factors in Aviation Systems. This will be accomplished by researching the following topics: effects of long duration spaceflight on crew performance and functioning and the steps that should be taken to enable long term spaceflight mission crews in lieu of accomplishing important missions; a human factor analysis should current human-machine design interfaces be enhanced to make manual rendezvous and docking in space easier to …

An Ir And Rf Based System For Functional Gait Analysis In A Multi-Resident Smart-Home, Erich Reinhardt Schafermeyer

Dissertations and Theses

Changes in the gait characteristics, such as walking speed and stride length, of a person living at home can be used to presage cognitive decline, predict fall potential, monitor long-term changes in cognitive impairment, test drug regimens, and more. This thesis presents a novel approach to gait analysis in a smart-home environment by leveraging new advances in inexpensive sensors and embedded systems to create novel solutions for in-home gait analysis. Using a simple, non-invasive hardware system consisting entirely of wall-mounted infrared and radio frequency sensor arrays, data is collected on the gait of subjects as they pass by. This data …

Semantic Inference On Clinical Documents: Combining Machine Learning Algorithms With An Inference Engine For Effective Clinical Diagnosis And Treatment, Shuo Yang, Ran Wei, Jingzhi Guo, Lida Xu

Information Technology & Decision Sciences Faculty Publications

Clinical practice calls for reliable diagnosis and optimized treatment. However, human errors in health care remain a severe issue even in industrialized countries. The application of clinical decision support systems (CDSS) casts light on this problem. However, given the great improvement in CDSS over the past several years, challenges to their wide-scale application are still present, including: 1) decision making of CDSS is complicated by the complexity of the data regarding human physiology and pathology, which could render the whole process more time-consuming by loading big data related to patients; and 2) information incompatibility among different health information systems (HIS) …

Development & Validation Of An Improved Biomechanical Model For Motion Analysis, Darren Dawson

Theses

Three dimensional motion analysis systems are utilised across a number of different disciplines, including clinical gait analysis, sports performance studies and analysis of tasks of daily living. These systems utilise biomechanical models which define body segment coordinate systems and calculate kinematic and kinetic relationships about the joints between adjacent coordinate systems. In this study, a biomechanical model for general use in motion analysis was developed and validated. It was designed to improve upon the accuracy and capability of currently available models. The newly developed model utilises state of the art techniques to accurately define body segment coordinate systems. Accurate predictive …

Fundamental Principles Of Tremor Propagation In The Upper Limb, Andrew D. Davidson, Steven Knight Charles

Faculty Publications

Although tremor is the most common movement disorder, there exist few effective tremor-suppressing devices, in part because the characteristics of tremor throughout the upper limb are unknown. To clarify, optimally suppressing tremor requires a knowledge of the mechanical origin, propagation, and distribution of tremor throughout the upper limb. Here we present the first systematic investigation of how tremor propagates between the shoulder, elbow, forearm, and wrist. We simulated tremor propagation using a linear, time-invariant, lumped-parameter model relating joint torques and the resulting joint displacements. The model focused on the seven main degrees of freedom from the shoulder to the wrist …

Structural Characteristics And Corrosion Behavior Of Bio-Degradable Zn-Li Alloys In Stent Application, Shan Zhao

Dissertations, Master's Theses and Master's Reports

Zinc has begun to be studied as a bio-degradable material in recent years due to its excellent corrosion rate and optimal biocompatibility. Unfortunately, pure Zn’s intrinsic ultimate tensile strength (UTS; below 120 MPa) is lower than the benchmark (about 300 MPa) for cardiovascular stent materials, raising concerns about sufficient strength to support the blood vessel. Thus, modifying pure Zn to improve its mechanical properties is an important research topic.

In this dissertation project, a new Zn-Li alloy has been developed to retain the outstanding corrosion behavior from Zn while improving the mechanical characteristics and uniform biodegradation once it is implanted …

Synthesis And Biological Evaluation Of Cannabinoid Receptor Ligands, Mariah Leigh Cole

Honors Theses

The cannabinoid receptors, members of the G-protein coupled receptor (GPCR) superfamily, have been implicated in numerous human physiological functions and diseases. These receptors, cannabinoid type 1 (CB1) and cannabinoid type 2 (CB2), are most concentrated in the central nervous system and immune cells, respectively, and have each become a target of therapeutic interest. Dual CB1/CB2 agonists such as delta-9-tetrahydrocannbinol (THC) have demonstrated efficacy in the treatment of nausea, pain, and glaucoma, but suffer from psychotropic effects mediated by CB1, motivating the search for CB2 selective therapeutic agents. Selective modulation of the CB2 receptor has therapeutic potential in human health disorders …

Valveless Pumping: The Reflected Pulse Wave Hypothesis, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

No abstract provided.

Surface Enabled Lab-On-A-Chip (Loc) Device For Protein Detection And Separation, Zhichao Wang

Dissertations, Master's Theses and Master's Reports

Sensitive and selective chemical/biological detection/analysis for proteins is essential for applications such as disease diagnosis, species phenotype identification, product quality control, and sample examination. Lab-on-a-chip (LOC) device provides advantages of fast analysis, reduced amount of sample requirements, and low cost, to magnificently facilitate protein detection research. Isoelectric focusing (IEF) is a strong and reliable electrophoretic technique capable of discerning proteins from complex mixtures based on the isoelectric point (pI) differences. It has experienced plenty of fruitful developments during previous decades which has given it the capability of performing with highly robust and reproducible analysis. This progress has made IEF devices …