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Biomedical engineering

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Full-Text Articles in Biomedical Engineering and Bioengineering

Development Of An Astrocyte/Glioma Co-Culture System For Measuring Cellular Dynamics, Urna Kansakar Feb 2019

Development Of An Astrocyte/Glioma Co-Culture System For Measuring Cellular Dynamics, Urna Kansakar

Doctoral Dissertations

Gliomas are brain tumors that primarily arise from glial cells. Gliomas account for 70% of the brain tumors and they are more prevalent in older adults. About 60% of the people with gliomas experience at least one seizure. Brain tumors can grow and metastasize to neighboring areas, thereby destroying normal brain cells. In a brain tumor microenvironment, both malignant cancer cells and healthy brain cells are present. Studies have shown that astrocytes may have a role in tumor growth in the brain. Monocultures cannot evaluate interactions between two cell types and does not accurately represent in vivo conditions. Thus, a ...


Foot Stress And Blood Flow Sensing Under High-Loading During Hip Surgery, Katie Paswaters, Esther Chen, Chris Cardenas, Claire Kingston, Brianna Rodebaugh Jun 2018

Foot Stress And Blood Flow Sensing Under High-Loading During Hip Surgery, Katie Paswaters, Esther Chen, Chris Cardenas, Claire Kingston, Brianna Rodebaugh

Mechanical Engineering

The PolyHIPS team was tasked with integrating sensors into Stryker’s hip arthroscopy boot that monitor blood flow and heel slip during hip surgery. During hip arthroscopy, the femur head is distracted from the acetabulum to create space in the joint for the surgeon to operate. This requires the use of up to 200 lbf. In order to maintain this space, the foot is held tightly in the boot. Complications can result from the foot being held too tightly in the boot during the procedure. The most common complication is neuropraxia, or temporary nerve damage. PolyHIPS proposes a solution that ...


3d Printed Force Transducers For In-Vitro Mitral Valve Chordae Tendineae Force Measurements, Hayley Chandler May 2018

3d Printed Force Transducers For In-Vitro Mitral Valve Chordae Tendineae Force Measurements, Hayley Chandler

Biomedical Engineering Undergraduate Honors Theses

Mitral valve surgery is incredibly prevalent in the United States with more than 40,000 mitral valve surgical procedures annually. Improving the imaging techniques used to diagnose these cases requires validation of 3D models through experimental data such as mechanical properties of the tissue. An essential part of this process for the mitral valve is measuring the force experienced by chordae tendineae. This has been achieved with brass force transducers but using a 3D printed design can have many benefits. In this study, 3D printed miniature c-shaped force transducers comparable to previous metal models were designed and created using Solidworks ...


Increasing Drug Delivery Efficacy Of Drug-Coated Balloons, Alexander Galan, Eric Bidinger, Franco Godoy, Shrusti Patel Apr 2018

Increasing Drug Delivery Efficacy Of Drug-Coated Balloons, Alexander Galan, Eric Bidinger, Franco Godoy, Shrusti Patel

Senior Theses

Peripheral artery disease (PAD), the narrowing of peripheral arteries located in areas such as the arms and legs, is a common disease that affects 12% to 20% of people over 65. Numerous therapies have been developed to treat PAD, the most recent technology being drug-coated balloons. Drug-coated balloons release drugs, such as Paclitaxel (PTX), into the arterial wall during balloon angioplasty to locally treat PAD. Current levels of drug transfer from the balloon to the vascular endothelium are at a low 10%-18%. Our Biomedical Engineering Senior Design project aims to increase drug delivery of drug-coated balloons by manipulating the ...


Development Of High Resolution Tools For Investigating Cardiac Arrhythmia Dynamics, Christopher Reed Gloschat Aug 2017

Development Of High Resolution Tools For Investigating Cardiac Arrhythmia Dynamics, Christopher Reed Gloschat

Engineering and Applied Science Theses & Dissertations

Every year 300,000 Americans die due to sudden cardiac death. There are many pathologies, acquired and genetic, that can lead to sudden cardiac death. Regardless of the underlying pathology, death is frequently the result of ventricular tachycardia and/or fibrillation (VT/VF). Despite decades of research, the mechanisms of ventricular arrhythmia initiation and maintenance are still incompletely understood.

A contributing factor to this lack of understanding is the limitations of the investigative tools used to study VT/VF. Arrhythmias are organ level phenomena that are governed by cellular interactions and as such, near cellular levels of resolution are needed ...


Compressive Sensing Framework For Mass Spectrometry Data Analysis, Khalfalla Ahmad Kh. Awedat Apr 2016

Compressive Sensing Framework For Mass Spectrometry Data Analysis, Khalfalla Ahmad Kh. Awedat

Dissertations

Mass Spectrometry (MS) data is ideal for identifying unique bio-signatures of diseases. However, the high dimensionality of MS data hinders any promising MS-based proteomics development. The goal of this dissertation is to develop an accurate classification tool by employing compressive sensing (CS). Not only can CS significantly reduce MS data dimensionality, but it also will allow for full reconstruction of original data. The framework developed in this work is based on using L2 and a mixed L2-L1 norms, allowing an overdetermined system to be resolved. The results show that the L2- based algorithm with regularization terms has a better performance ...


Plasticity Of The Cortical Representation Of Finger Extensors Induced By Paired Associative Stimulation, Ian Anthony Gerard Lafond Dec 2015

Plasticity Of The Cortical Representation Of Finger Extensors Induced By Paired Associative Stimulation, Ian Anthony Gerard Lafond

Dissertations

This dissertation first explored associative plasticity of the human motor cortical representation with the use of noninvasive transcranial magnetic stimulation (TMS) paired with peripheral electrical stimulation. Paired Associative Stimulation (PAS) has grown in popularity because of its potential clinical applications. PAS techniques are used in combination with electromyography (EMG) measurements to study cortical excitability and features of hand movement. This work focuses on a cohesive approach to answer central questions about: the ideal mechanism to facilitate cortical plasticity via PAS, the interaction between the behavior performed and type of stimulation delivered to the targeted cortical network and the effects of ...


New Design Of Nasogastric Decompression Tube That Incorporates A Self-Cleaning Brushing Mechanism, Nichole Abla, Lindsay Rucker, Paige Schroder May 2015

New Design Of Nasogastric Decompression Tube That Incorporates A Self-Cleaning Brushing Mechanism, Nichole Abla, Lindsay Rucker, Paige Schroder

Senior Theses

Many hospitalized patients require the removal of secretions that accumulate in the stomach and must be removed by a nasogastric tube, which unfortunately clogs often. This project outlines the redesign of the nasogastric tube that will ideally prevent nasogastric tube clogging by incorporating a brush mechanism and a contracting tip mechanism, to act as preventative measures against clogging.


Determining The Transport Enhancement Of Sodium Fluorescein In Mechanically-Loaded Canine Tibia, Andrew Joseph Zak Jan 2015

Determining The Transport Enhancement Of Sodium Fluorescein In Mechanically-Loaded Canine Tibia, Andrew Joseph Zak

ETD Archive

Quantitative research concerning the impact of mechanical loading on the transport properties of bone has several critical applications. One such application is the effect of a microgravity environment, where the lack of mechanical forces on bone has been shown to negatively impact both growth and repair. A method has been developed in our lab that can potentially allow for the measurement of the effective permeability of large molecules (i.e., 300-15,000 Da in size) in bone tissue under both unloaded and mechanically loaded conditions. In proof-of-concept experiments, previous students have measured the effective diffusivity of the model solute, sodium ...


Time And Temperature Dependent Surface Tension Measurements Of Responsive Protein-Based Polymer Surfactant Solutions, Hakan Celik Jan 2015

Time And Temperature Dependent Surface Tension Measurements Of Responsive Protein-Based Polymer Surfactant Solutions, Hakan Celik

ETD Archive

A three-armed star elastin-like polypeptide (ELP-foldon) has thermoreversible character which exhibits phase separation above a transition temperature (Tt) in physiologic salt concentrations. At lower salt concentration, the ELP-foldon behaves like a thermoresponsive surfactant, exhibiting micelle formation above its Tt. The purpose of this study is characterize the surfactant behavior of the ELP-foldon at air-liquid interface by measuring the surface tension. The surface tension is measured as a function of time for different ELP concentrations from 10 nM to 50 ℗æM and over range of temperatures from 25 to 35 ℗¿ using the axisymmetric drop shape analysis (ADSA). The ADSA is a ...


Development Of Biomechanical Analysis Techniques For Fatigue Of Transtibial Prosthetic Socket And Pylon Interactions, Thomas Z. Sudbury May 2014

Development Of Biomechanical Analysis Techniques For Fatigue Of Transtibial Prosthetic Socket And Pylon Interactions, Thomas Z. Sudbury

Honors Theses

The lack of formal, engineering based information is prevalent in the prosthetic industry. Currently, very few prosthetic manufacturing companies can definitively tell their patients how long their products will last. Because of this lack of information, many amputee patients will experience failure of their transtibial prosthetic device during daily activities. One such failure occurs from the fatigue of everyday use. Fatigue failures originate from the repeated application of certain loading conditions. These repeated loads usually occur for millions of cycles before a transtibial prosthetic catastrophically fails. The purpose of this study is to develop a testing procedure and apparatus that ...


Design Of Recombinant Tenebrio Molitor Antifreeze Protein For Purification Using Elastin-Like Polypeptide Tag, Joongseok Oh Jan 2014

Design Of Recombinant Tenebrio Molitor Antifreeze Protein For Purification Using Elastin-Like Polypeptide Tag, Joongseok Oh

ETD Archive

Fusion protein technologies can aid to improve solubility of recombinant protein from microorganisms and help recombinant protein purification. Elastin-like polypeptides (ELP) as a fusion tag can be utilized to facilitate the purification of recombinant proteins because ELP can provide its thermally responsive behavior to ELP tagged proteins. An ELP tag can be used as the purification carrier through inverse transition cycling (ITC), which is a simple and non chromatographic separation process. The purification through ITC can reduce cost and can be quickly performed compared to other purification methods. However, we further considered ELP tag removal because it may possibly hinder ...


Human Motion Analysis With Wearable Inertial Sensors, Xi Chen Aug 2013

Human Motion Analysis With Wearable Inertial Sensors, Xi Chen

Doctoral Dissertations

High-resolution, quantitative data obtained by a human motion capture system can be used to better understand the cause of many diseases for effective treatments. Talking about the daily care of the aging population, two issues are critical. One is to continuously track motions and position of aging people when they are at home, inside a building or in the unknown environment; the other is to monitor their health status in real time when they are in the free-living environment. Continuous monitoring of human movement in their natural living environment potentially provide more valuable feedback than these in laboratory settings. However ...


Three-Dimensional Kinematic Analysis Using The Xbox Kinect, Robert Matthew Wham May 2012

Three-Dimensional Kinematic Analysis Using The Xbox Kinect, Robert Matthew Wham

Chancellor’s Honors Program Projects

No abstract provided.


One-Dimensional Radial Diffusion Of Small Molecules (376 Da) In Bone Tissue, Kurt W. Farrell Jan 2011

One-Dimensional Radial Diffusion Of Small Molecules (376 Da) In Bone Tissue, Kurt W. Farrell

ETD Archive

The flow of nutrients through any biological tissue is important to maintain homeostasis. If the transport process is understood, medical research teams can better design medications, prosthetic implants, and tissue scaffolds. Additionally, transport rates help physicians to better understand disease states and wound healing, including minor injuries such as breaks and sprains, which will aid in better diagnoses. We developed a novel method that measures the rate of diffusion in vitro, of fluorescein sodium salt. Samples were incubated at 37°C in a 5 CO2 atmosphere for various periods of time. Samples were sliced and analyzed using Image-Pro Plus and ...


Spectral Analysis Of Pathological Acoustic Speech Waveforms, Priyanka Medida Jan 2009

Spectral Analysis Of Pathological Acoustic Speech Waveforms, Priyanka Medida

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biomedical engineering is the application of engineering principles and techniques to the medical field. The design and problem solving skills of engineering are combined with medical and biological science, which improves medical disorder diagnosis and treatment. The purpose of this study is to develop an automated procedure for detecting excessive jitter in speech signals, which is useful for differentiating normal from pathologic speech. The fundamental motivation for this research is that tools are needed by speech pathologists and laryngologists for use in the early detection and treatment of laryngeal disorders. Acoustical analysis of speech was performed to analyze various features ...


A Three-Dimensional Quantitative Biomechanical Analysis Of Left Handed Scanning, William Ray Brown Jan 2007

A Three-Dimensional Quantitative Biomechanical Analysis Of Left Handed Scanning, William Ray Brown

Retrospective Theses and Dissertations

No abstract provided.


Calcium Phosphate Compatible Bone Cement: Characterization, Bonding Properties And Tissue Response , Maria Lynn Roemhildt Jan 2002

Calcium Phosphate Compatible Bone Cement: Characterization, Bonding Properties And Tissue Response , Maria Lynn Roemhildt

Retrospective Theses and Dissertations

A novel, inorganic, bone cement, containing calcium phosphate, developed for implant fixation was evaluated. Setting properties were determined over a range of temperatures. The flow of the cement was greatly increased by application of vibration. Changes in the cement during hydration and aging were evaluated. Compressive strength of the cement over time was studied under simulated physiological conditions from 1 hour to 1 year after setting. After 1 day, this cement had equivalent compressive strength to commercially used PMMA cement. The strength was found to increase over 1 month and high strength was maintained up to 1 year.;The shear ...


Total Elbow Replacement In The Dog: Development And Evaluation , Michael Gerard Conzemius Jan 2000

Total Elbow Replacement In The Dog: Development And Evaluation , Michael Gerard Conzemius

Retrospective Theses and Dissertations

Elbow osteoarthritis (OA) is the most common cause of forelimb lameness in the dog. The goal of nonsurgical and/or surgical management of the diseases that cause elbow OA is to slow the progression OA in the joint and reduce lameness in the patient. Nonsurgical and surgical management of these conditions frequently leads to unsatisfactory results. Current treatment alternatives for dogs with moderate to severe elbow OA include nonsurgical management, removing loose bodies and osteophytes from the joint, and arthrodesis. Similarly, these treatments frequently lead to a poor outcome. Improvements in implant design and surgical techniques have made total elbow ...


Micro And Nanopatterned Biodegradable Polymer Films For Peripheral Nerve Regeneration , Cheryl Ann Miller Jan 2000

Micro And Nanopatterned Biodegradable Polymer Films For Peripheral Nerve Regeneration , Cheryl Ann Miller

Retrospective Theses and Dissertations

Annually over 200,000 surgeries are attempted to repair peripheral nerve damage.1 Without these surgeries, peripheral nerve transections have little hope of reinnervating the effector organ and becoming fully functional if the nerve endings are separated by a centimeter or more. Currently, transections are repaired with nerve autografts removed from one part of the body to repair the injured site. Autografting causes deinnervation of the donor site and tissue availability is limited.;An alternative nerve repair method to grafting is an entubulization method where a conduit is used to connect the nerve endings. The conduit allows for chemical communications ...


Utility Of Spectrum And Wavelet Analysis Of Heart Rate Variability As A Tool To Assess Orthostatic Intolerance , Kichang Lee Jan 2000

Utility Of Spectrum And Wavelet Analysis Of Heart Rate Variability As A Tool To Assess Orthostatic Intolerance , Kichang Lee

Retrospective Theses and Dissertations

Three studies were performed to test the hypotheses: (1) lower body negative pressure (LBNP) tolerance, autonomic, and cardiovascular responses to the LBNP are reproducible, (2) women have a lower LBNP tolerance and less ability to maintain homeostasis in cardiovascular system against orthostatic stress, and (3) wavelet analysis technique is a unique tool to study the autonomic nervous activities during LBNP test. College-age men and women underwent graded LBNP to either presyncope or -100 mmHg in increments of 10 mmHg negative pressure every 6 minutes;The LBNP tolerance were highly reproducible (cumulative stress index: 1698 +/- 171 vs 1938 +/- 139, trial 1 ...


Algorithms For Enhancing Pattern Separability, Feature Selection And Incremental Learning With Applications To Gas Sensing Electronic Nose Systems , Robi Polikar Jan 2000

Algorithms For Enhancing Pattern Separability, Feature Selection And Incremental Learning With Applications To Gas Sensing Electronic Nose Systems , Robi Polikar

Retrospective Theses and Dissertations

Three major issues in pattern recognition and data analysis have been addressed in this study and applied to the problem of identification of volatile organic compounds (VOC) for gas sensing applications. Various approaches have been proposed and discussed. These approaches are not only applicable to the VOC identification, but also to a variety of pattern recognition and data analysis problems. In particular, (1) enhancing pattern separability for challenging classification problems, (2) optimum feature selection problem, and (3) incremental learning for neural networks have been investigated;Three different approaches are proposed for enhancing pattern separability for classification of closely spaced, or ...


A Three-Dimensional, Dynamic Model Of The Human Body For Lifting Motions , Jason Clay Gillette Jan 1999

A Three-Dimensional, Dynamic Model Of The Human Body For Lifting Motions , Jason Clay Gillette

Retrospective Theses and Dissertations

Lower back pain is prevalent in society and manual lifting has been linked as one potential cause of these types of injuries. Therefore, the 3dLift biomechanical model was developed in this research with the goal of quantitatively analyzing lifting motions. The model divided the body into fifteen segments that were connected by fourteen anatomical joints. During experimental trials, a volunteer subject lifted an object using four different lifting combinations: symmetric leglifts, asymmetric leglifts, symmetric backlifts, and asymmetric backlifts. In order to individualize the 3dLift model, anthropometric parameters were estimated using measurements taken on the subject. During the lifting trials, the ...


Development Of A Coupled Model Of The Cardiorespiratory And Thermoregulatory Systems , Dawn Denise Downey Jan 1998

Development Of A Coupled Model Of The Cardiorespiratory And Thermoregulatory Systems , Dawn Denise Downey

Retrospective Theses and Dissertations

A model of the human body which integrates the variables involved in temperature regulation and blood gas transport within the cardiovascular and respiratory systems is presented in this dissertation. It expands upon previous work developed by the author to model the competition between skin and muscles when both require increased blood flows during exercise and/or heat stress. First, a detailed study of the control relations used to predict skin blood flow was undertaken. Four other control relations employed in the model were also examined and modified as indicated by empirical results found in literature;Several important cases were then ...


Development Of A Multiple-Lumen Nerve Cuff Utilizing Growth Stimulant Patterns For Controlled Regeneration , Yueh-Sheng Chen Jan 1998

Development Of A Multiple-Lumen Nerve Cuff Utilizing Growth Stimulant Patterns For Controlled Regeneration , Yueh-Sheng Chen

Retrospective Theses and Dissertations

Silicone rubber multiple-lumen nerve cuffs were used to compare the effectiveness of two varieties of nerve growth stimulants (collagen and a mixture of collagen, fibronectin, and laminin) at the same time for regenerating cables across the same gap. The right sciatic nerve was transected in adult Sprague-Dawley rats. The proximal and distal stumps were inserted each into an end of the single lumen portion of a multiple-lumen cuff in which different chemical fillings were used in 6 tubes of the multiple lumen portion of the cuff. The filling pattern alternated with collagen gel or with a gel mixture of collagen ...


A Quantitative Estimation Of Regulation And Transport Limitations In The Human Cardiopulmonary System , Sharmista Chatterjee Jan 1997

A Quantitative Estimation Of Regulation And Transport Limitations In The Human Cardiopulmonary System , Sharmista Chatterjee

Retrospective Theses and Dissertations

The object of this dissertation is to quantitatively describe the regulation of some of the exchange processes within the human body. Conceptually this dissertation is divided into two sections. In the first section a macroscopic view was adopted to describe the overall regulation of the cardiovascular and respiratory systems. These overall system models were used as heuristic tools to gain an understanding of physiological behavior in micro-gravity. In the second section, a microscopic view was used to estimate the role played by the surfactant system of the lung in regulating the transfer of fluid across the pulmonary-capillary wall;The basis ...


Calcium Phosphate Ceramic Composites Used For Orthopedic Implant Applications , Curtis Eugene Olson Jan 1996

Calcium Phosphate Ceramic Composites Used For Orthopedic Implant Applications , Curtis Eugene Olson

Retrospective Theses and Dissertations

The objective of the first of two research projects was to make a new composite material that would have both bone bonding capabilities and appropriate mechanical properties for use in orthopedic applications. Implant-bone responses were compared using transcortical implants designed from osteoceramic fired in air, osteoceramic fired in hydrogen, 316L stainless steel mixed with aggregates of osteoceramic, 316L stainless steel, and ultra high molecular weight polyethylene mixed with aggregates of osteoceramic. The osteoceramic material, developed at Iowa State University, was a biologically active composite consisting of tricalcium phosphate and magnesium aluminate spinel;Ten of each of these implants were placed ...


Computer Simulation Of Coronary Blood Flow , Brian Christopher Frake Jan 1995

Computer Simulation Of Coronary Blood Flow , Brian Christopher Frake

Retrospective Theses and Dissertations

A computer model to simulate coronary fluid dynamics has been developed which can give some insight into the role of hemodynamics in health and disease. Although this study focuses mainly on coronary blood flow, the complete model consists of all major branches of the systemic circulation as well as the left epicardial coronary circulation;The flow equations are obtained by integrating the one-dimensional continuity and momentum equations over the cross-section of the artery to give a relationship between the primary variables of interest, the pressure and flowrate. An arctangent model was used as a constitutive equation to describe the pressure-area ...


Modeling Joint Kinetics In The Tkatchev Release Move , Martha Nichols-Ketchum Jan 1994

Modeling Joint Kinetics In The Tkatchev Release Move , Martha Nichols-Ketchum

Retrospective Theses and Dissertations

This study developed a three-dimensional computer simulation model of the Tkatchev release move on the men's horizontal bar. The model used the Hanavan human body model and the inverse dynamics approach to predict resultant forces and torques at the joints during performance. The model was used to determine aspects of the performance that contribute to the risk of injury and to determine strength and flexibility requirements for the skill;This study was done in two parts. In Part 1, kinetic parameters were calculated from actual performances of Tkatchevs. Two college-level male gymnasts each performed 9-10 Tkatchevs during a single ...


Water And Electrolyte Regulation During Space Flight And Exercise , Susan Elizabeth Doty Jan 1994

Water And Electrolyte Regulation During Space Flight And Exercise , Susan Elizabeth Doty

Retrospective Theses and Dissertations

When one is exposed to microgravity, fluid which is normally pooled in the lower extremities is redistributed headward and weight bearing bones begin to demineralize due to reduced mechanical stresses. The kidney, which is the primary regulator of body fluid volume and composition, responds to the fluid shift and bone demineralization by increasing the urinary output of water, sodium, and calcium. This research involves developing a mathematical description of how water and electrolytes are internally redistributed and exchanged with the environment during space flight. Various levels of activity are also considered, since it is believed that exercise can prevent some ...