Matching Items (53)
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Description
Intracranial aneurysms, which form in the blood vessels of the brain, are particularly dangerous because of the importance and fragility of the human brain. When an intracranial aneurysm gets large it poses a significant risk of bursting and causing subarachnoid hemorrhaging (SAH), a possibly fatal condition. One possible treatment involves

Intracranial aneurysms, which form in the blood vessels of the brain, are particularly dangerous because of the importance and fragility of the human brain. When an intracranial aneurysm gets large it poses a significant risk of bursting and causing subarachnoid hemorrhaging (SAH), a possibly fatal condition. One possible treatment involves placing a stent in the vessel to act as a flow diverter. In this study we look at the hemodynamics of two geometries of idealized basilar tip aneurysms, at 2,3, and 4 ml/s pulsatile flow, at three different points in the cardiac cycle. The smaller model had neck and dome diameters of 2.67 mm and 4 mm respectively, while the larger aneurysm had neck and dome diameters of 3 mm and 6 mm respectively. Both diameters and the dome to neck ratio increased in the second model, representing growth over time. Flow was analyzed using stereoscopic particle image velocimetry (PIV) for both geometries in untreated models, as well as after treatment with a high porosity Enterprise stent (Codman and Shurtleff Inc.). Flow in the models was characterized by root mean square velocity in the aneurysm and neck plane, cross neck flow, max aneurysm vorticity, and total aneurysm kinetic energy. It was found that in the smaller aneurysm model (model 1), Enterprise stent treatment reduced all flow parameters substantially. The smallest reduction was in max vorticity, at 42.48%, and the largest in total kinetic energy, at 75.69%. In the larger model (model 2) there was a 52.18% reduction in cross neck flow, but a 167.28% increase in aneurysm vorticity. The other three parameters experienced little change. These results, along with observed velocity vector fields, indicate a noticeable diversion of flow away from the aneurysm in the stent treated model 1. Treatment in model 2 had a small flow diversion effect, but also altered flow in unpredictable ways, in some cases having a detrimental effect on aneurysm hemodynamics. The results of this study indicate that Enterprise stent treatment is only effective in small, relatively undeveloped aneurysm geometries, and waiting until an aneurysm has grown too large can eliminate this treatment option altogether.
ContributorsLindsay, James Bryan (Author) / Frakes, David (Thesis director) / LaBelle, Jeffrey (Committee member) / Nair, Priya (Committee member) / Barrett, The Honors College (Contributor) / School of Humanities, Arts, and Cultural Studies (Contributor)
Created2013-05
Description
The purpose of this thesis was to explore how changes in the geometry of a bifurcating cerebral aneurysm will affect the hemodynamics in idealized models after stent treatment. This thesis explores the use of a computationally modeled Enterprise Vascular Reconstruction Device (Cordis, East Bridgewater, NJ), a high porosity and closed

The purpose of this thesis was to explore how changes in the geometry of a bifurcating cerebral aneurysm will affect the hemodynamics in idealized models after stent treatment. This thesis explores the use of a computationally modeled Enterprise Vascular Reconstruction Device (Cordis, East Bridgewater, NJ), a high porosity and closed cell design. The models represent idealized cases of saccular aneurysms with dome sizes of either 4mm or 6mm and a dome to neck ratio of either 3:2 or 2:1. Two aneurysm contact angles are studied, one at 45 degrees and the other at 90 degrees. The stent was characterized and deployed with the use of Finite Element Analysis into each model. Computational Fluid Dynamic principles were applied in series of simulations on treated and untreated models. Data was gathered in the neck plane for the average velocity magnitude, root mean squared velocity, average flow vector angle of deflection, and the cross neck flow rate. Within the aneurysm, the average velocity magnitude, root mean squared velocity, and average pressure were calculated. Additionally, the mass flow rate at each outlet was recorded. The results of this study indicate that the Enterprise Stent was most effective in the sharper, 90 degree geometry of Model 3. Additionally, the stent had an adverse effect on the Models 1 and 4, which had the smallest neck sizes. Conclusions are that the Enterprise Stent, as a stand-alone treatment method is only reliable in situations that take advantage of its design.
ContributorsThomas, Kyle Andrew (Author) / Frakes, David (Thesis director) / LaBelle, Jeffrey (Committee member) / Babiker, Haithem (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
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Description
Electrochemical sensors function by detecting electroactive species at the electrode surface of a screen printed sensor. As more force is applied, the concentration of electroactive species at the surface of the sensor increases and a larger current is measured. Thus, when all conditions including voltage are made constant, as in

Electrochemical sensors function by detecting electroactive species at the electrode surface of a screen printed sensor. As more force is applied, the concentration of electroactive species at the surface of the sensor increases and a larger current is measured. Thus, when all conditions including voltage are made constant, as in Amp i-t, a quantifiable current can be read and the force applied can be calculated. Two common electrochemical techniques in which current is measured, cyclic voltammetry(CV) and amperometric i-t(Amp i-t), were used. A compressible sensor capable of transducing a force and acquiring feedback was created.
ContributorsFeldman, Austin Marc (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Santello, Marco (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
Description
This report outlines the current methods and instrumentation used for diabetes monitoring and detection, and evaluates the problems that these methods face. Additionally, it will present an approach to remedy these problems. The purpose of this project is to create a potentiostat that is capable of controlling a diabetes meter

This report outlines the current methods and instrumentation used for diabetes monitoring and detection, and evaluates the problems that these methods face. Additionally, it will present an approach to remedy these problems. The purpose of this project is to create a potentiostat that is capable of controlling a diabetes meter that monitors multiple biological markers simultaneously. Glucose is the most commonly measured biomarker for diabetes. However, it provides only a limited amount of information. In order to give the user of the meter more information about the progression of his or her disease, the concentrations of several different biological markers for diabetes may be measured using a system that operates in a similar fashion to blood glucose meters. The potentiostat provides an input voltage into the electrode sensor and receives the current from the sensor as the output. From this information, the impedance may be calculated. The concentrations of each of the biomarkers in the blood sample can then be determined. In an effort to increase sensitivity, the diabetes meter forgoes the use of amperometric i-t in favor of the electrochemical impedance spectroscopy technique. A three-electrode electrochemical sensor is used with the meter. In order to perform simultaneous and rapid testing of biomarker concentration, a single multisine input wave is generated using a hardware implementation of a summing amplifier and waveform generators.
ContributorsWu, Diane Zhang (Author) / LaBelle, Jeffrey (Thesis director) / Bakkaloglu, Bertan (Committee member) / Spano, Mark (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2013-05
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Description
Development of a rapid and label-free Electrochemical Impedance Spectroscopy (EIS) biosensor for Cardiovascular Disease (CVD) detection based on Inerluekin-18 (IL-18) sensitivity was proposed to fill the technology gap between rapid and portable CVD point-of-care diagnosis. IL-18 was chosen for this CVD biosensor due to its ability to detect plaque vulnerability

Development of a rapid and label-free Electrochemical Impedance Spectroscopy (EIS) biosensor for Cardiovascular Disease (CVD) detection based on Inerluekin-18 (IL-18) sensitivity was proposed to fill the technology gap between rapid and portable CVD point-of-care diagnosis. IL-18 was chosen for this CVD biosensor due to its ability to detect plaque vulnerability of the heart. Custom (hand) made sensors, which utilized a three electrode configuration with a gold disk working electrode, were created to run EIS using both IL-18 and anti-IL-18 molecules in both purified and blood solutions. The EIS results for IL-18 indicated the optimal detection frequency to be 371Hz. Blood interaction on the working electrode increased the dynamic range of impedance values for the biosensor. Future work includes Developing and testing prototypes of the biosensor along with determining if a Nafion based coating on the working electrode will reduce the dynamic range of impedance values caused by blood interference.
ContributorsJha, Amit (Author) / LaBelle, Jeffrey (Thesis director) / Mossman, Kenneth (Committee member) / Frakes, David (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor) / Department of Management (Contributor)
Created2013-05
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Description
The use of microelectrode arrays (MEA) to electroporate cells is now a reliable way of transfecting RNA interfering substances with high viability and efficiency. However, as the 50-200 micron electrodes are coated with many cells, there are differences in both viability and efficiency between the outside and inside of the

The use of microelectrode arrays (MEA) to electroporate cells is now a reliable way of transfecting RNA interfering substances with high viability and efficiency. However, as the 50-200 micron electrodes are coated with many cells, there are differences in both viability and efficiency between the outside and inside of the electrode. This is due to the field created by the electrode, which has higher intensities toward the outside and lower intensities toward the middle. In order to get the electric field to spread in a more even manner, an "Anodisc" inorganic membrane seeded with cells was placed on the MEA to act as a buffer to the electric fields. One hundred percent transfection efficiency on live cells was found on one sample, though there were problems encountered along the experimental process that introduced error into the results, some of which included the inability for cells to grow to high levels of confluency on the Anodisc as well as the inverted imaging technique used on the opaque disc.
ContributorsDonnelly, Kyle Robert (Author) / Muthuswamy, Jitendran (Thesis director) / Haynes, Karmella (Committee member) / LaBelle, Jeffrey (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
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Description
This study regarding a proposed variable stiffness structure will focus on structure geometry as a proof of concept attempt to develop a new design for energy dispersion. The structure was designed such that as a greater force is experienced, more of the structure comes into contact with itself making the

This study regarding a proposed variable stiffness structure will focus on structure geometry as a proof of concept attempt to develop a new design for energy dispersion. The structure was designed such that as a greater force is experienced, more of the structure comes into contact with itself making the structure stiffer, hence the name variable stiffness structure. This variable stiffness will provide softer structure properties under small loads and stiffer properties under larger loads. This allows an impact to be absorbed by the structure under low loads without compromising structure stiffness that provides protection at higher loads. Intended function of this structure is an intermediate layer in protective gear such as helmets for military and athletic applications, athletic padding, or everyday applications such as the soles of shoes or medical crutches. Proof of concept for the variable stiffness structures was successful as validated by the observance of three distinct slopes in the load vs. compression data reflecting the desired three contact regions on four different structures tested. Structures that performed as intended were also more successful at dispersing energy as calculated by the integral of the load vs. compression curves. Observed trends include desirable increased contact spacing and geometry thickness for a 2:1 height to width structure ratio. Since these results are on the limits of the optimization conditions, additional testing will be required to determine true optimal design. Energy dispersion trends would suggest that structure 135 was the most successful structure at dissipating energy. While this structure was successful, (1.42 J of energy dissipated in the variable stiffness region) structure 313 outperformed it by nearly 1 J (2.25 J average). Upon examination of testing footage, structure 313 displayed the unique quality of engaging multiple contact points in each contact region. This suggests that the number of contact points may be the unobserved variable that will further the variable stiffness structure design for improved energy dispersion in future iterations. With further development, the variable stiffness structures could be an influential means of energy dispersion for utilization in a wide variety of applications.
ContributorsCampbell, Ryan Gregory (Author) / LaBelle, Jeffrey (Thesis director) / Lathers, Steven (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
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Description
The purpose of this research was to determine and evaluate glutamate oxidase's ability to detect levels of glutamate as part of a working sensor capable of quantifying and detecting stress within the body in the case of adverse neurological events such as traumatic brain injury. Using electrochemical impedance spectroscopy (EIS),

The purpose of this research was to determine and evaluate glutamate oxidase's ability to detect levels of glutamate as part of a working sensor capable of quantifying and detecting stress within the body in the case of adverse neurological events such as traumatic brain injury. Using electrochemical impedance spectroscopy (EIS), a linear dynamic range of glutamate was detected with a slope of 36.604 z/ohm/[pg/mL], a lower detection limit at 12.417 pg/mL, correlation of 0.97, and an optimal binding frequency of 117.20 Hz. After running through a frequency sweep the binding frequency was determined based on the highest consistent reproducibility and slope. The sensor was found to be specific against literature researched non-targets glucose, albumin, and epinephrine and working in dilutions of whole blood up to a concentration of 25%. With the implementation of Nafion, the sensor had a 250% improvement in signal and 155% improvement in correlation in 90% whole blood, illustrating the promise of a working blood sensor. Future work includes longitudinal studies and utilizing mesoporous carbon as the immobilization platform and incorporating this as part of a continuous, multiplexed blood sensor with glucose oxidase.
ContributorsLam, Alexandria Nicole (Author) / LaBelle, Jeffrey (Thesis director) / Ankeny, Casey (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
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Description
The goal of this project was to create a card game that would quickly and easily allow medical professionals to learn important information. This project seeks to advance ways in which medical staff gain information about disease outbreaks through the creation of a card game which teaches players the proper

The goal of this project was to create a card game that would quickly and easily allow medical professionals to learn important information. This project seeks to advance ways in which medical staff gain information about disease outbreaks through the creation of a card game which teaches players the proper steps and procedure to triage and treat patients who are suspected to have Ebola Hemorrhagic Fever, which was not done properly during the recent outbreak. To create this game, research was conducted on the information given by the Center for Disease Control and Prevention (CDC) on the various steps to triaging those who were suspected of having Ebola. Various prototypes of the game were made and tested to optimize the win-lose ratio while still being an enjoyable game to play. This card game is fast-paced, small, and can be played either individually or with more than one person. It is loosely based off of Solitaire. This game has gone through three prototypes of the cards as well as a few brief testing periods. Through the methods and procedure used in this game's creation, it has been concluded that this method is a great way to easily teach players a proper procedure, and that this method of game can be applied to other disease breakouts and even to other fields where information must be learned quickly. Future steps for this game include improving the graphic art used in the cards, and continuing on to create a smartphone application.
ContributorsHenriksen, Carissa (Co-author) / Pratt, Breanna (Co-author) / LaBelle, Jeffrey (Thesis director) / Coursen, Jerry (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
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Description
Chronic stress has been linked as a probable contributor to a number of health problems that plague the world today. Obesity, cardiovascular disease, depression, and osteoporosis are all common health risks believed to be exacerbated by stress. While it is nether realistic nor desirable to completely eliminate stress in an

Chronic stress has been linked as a probable contributor to a number of health problems that plague the world today. Obesity, cardiovascular disease, depression, and osteoporosis are all common health risks believed to be exacerbated by stress. While it is nether realistic nor desirable to completely eliminate stress in an individual, proper stress management is important to a healthy lifestyle. Homeostasis is the primary mechanism by which stress, and the stress response, should be analyzed. Environmental factors known as stressors elicit responses from the body, which can be measured in terms of duration and magnitude. These two factors determine the homeostatic response from the body. This thesis proposes the study of heart rate variability (HRV) to measure the response of the autonomic nervous system through time domain analysis (the length of interbeat intervals) and frequency domain analysis (the differences between the lengths of consecutive interbeat intervals). Even with many possible problems, this data still represents valuable proof of concept that HRV analysis may be of use in identifying stress.
ContributorsUchimura, Kevin (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Stabenfeldt, Sarah (Committee member) / Barrett, The Honors College (Contributor)
Created2012-05