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In the search for chemical biosensors designed for patient-based physiological applications, non-invasive diagnostic approaches continue to have value. The work described in this thesis builds upon previous breath analysis studies. In particular, it seeks to assess the adsorptive mechanisms active in both acetone and ethanol biosensors designed for

In the search for chemical biosensors designed for patient-based physiological applications, non-invasive diagnostic approaches continue to have value. The work described in this thesis builds upon previous breath analysis studies. In particular, it seeks to assess the adsorptive mechanisms active in both acetone and ethanol biosensors designed for breath analysis. The thermoelectric biosensors under investigation were constructed using a thermopile for transduction and four different materials for biorecognition. The analytes, acetone and ethanol, were evaluated under dry-air and humidified-air conditions. The biosensor response to acetone concentration was found to be both repeatable and linear, while the sensor response to ethanol presence was also found to be repeatable. The different biorecognition materials produced discernible thermoelectric responses that were characteristic for each analyte. The sensor output data is presented in this report. Additionally, the results were evaluated against a mathematical model for further analysis. Ultimately, a thermoelectric biosensor based upon adsorption chemistry was developed and characterized. Additional work is needed to characterize the physicochemical action mechanism.
ContributorsWilson, Kimberly (Author) / Guilbeau, Eric (Thesis advisor) / Pizziconi, Vincent (Thesis advisor) / LaBelle, Jeffrey (Committee member) / Arizona State University (Publisher)
Created2011
Description
Volume depletion can lead to migraines, dizziness, and significant decreases in a subject's ability to physically perform. A major cause of volume depletion is dehydration, or loss in fluids due to an imbalance in fluid intake to fluid excretion. Because proper levels of hydration are necessary in order to maintain

Volume depletion can lead to migraines, dizziness, and significant decreases in a subject's ability to physically perform. A major cause of volume depletion is dehydration, or loss in fluids due to an imbalance in fluid intake to fluid excretion. Because proper levels of hydration are necessary in order to maintain both short and long term health, the ability to monitor hydration levels is growing in clinical demand. Although devices capable of monitoring hydration level exist, these devices are expensive, invasive, or inaccurate and do not offer a continuous mode of measurement. The ideal hydration monitor for consumer use needs to be characterized by its portability, affordability, and accuracy. Also, this device would need to be noninvasive and offer continuous hydration monitoring in order to accurately assess fluctuations in hydration data throughout a specified time period. One particular method for hydration monitoring that fits the majority of these criteria is known as bioelectric impedance analysis (BIA). Although current devices using BIA do not provide acceptable levels of accuracy, portability, or continuity in data collection, BIA could potentially be modified to fit many, if not all, desired customer specifications. The analysis presented here assesses the viability of using BIA as a new standard in hydration level measurement. The analysis uses data collected from 22 subjects using an existing device that employs BIA. A regression derived for estimating TBW based on the parameters of age, weight, height, sex, and impedance is presented. Using impedance data collected for each subject, a regression was also derived for estimating impedance based on the factors of age, weight, height, and sex. The derived regression was then used to calculate a new impedance value for each subject, and these new impedance values were used to estimate TBW. Through a paired-t test between the TBW values derived by using the direct measurements versus the calculated measurements of impedance, the two samples were found to be comparable. Considerations for BIA as a noninvasive measurement of hydration are discussed.
ContributorsTenorio, Jorge Antonio (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Spano, Mark (Committee member) / Barrett, The Honors College (Contributor) / W. P. Carey School of Business (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
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Description
The American Diabetes Association reports that diabetes costs $322 billion annually and affects 29.1 million Americans. The high out-of-pocket cost of managing diabetes can lead to noncompliance causing serious and expensive complications. There is a large market potential for a more cost-effective alternative to the current market standard of screen-printed

The American Diabetes Association reports that diabetes costs $322 billion annually and affects 29.1 million Americans. The high out-of-pocket cost of managing diabetes can lead to noncompliance causing serious and expensive complications. There is a large market potential for a more cost-effective alternative to the current market standard of screen-printed self-monitoring blood glucose (SMBG) strips. Additive manufacturing, specifically 3D printing, is a developing field that is growing in popularity and functionality. 3D printers are now being used in a variety of applications from consumer goods to medical devices. Healthcare delivery will change as the availability of 3D printers expands into patient homes, which will create alternative and more cost-effective methods of monitoring and managing diseases, such as diabetes. 3D printing technology could transform this expensive industry. A 3D printed sensor was designed to have similar dimensions and features to the SMBG strips to comply with current manufacturing standards. To make the sensor electrically active, various conductive filaments were tested and the conductive graphene filament was determined to be the best material for the sensor. Experiments were conducted to determine the optimal print settings for printing this filament onto a mylar substrate, the industry standard. The reagents used include a mixture of a ferricyanide redox mediator and flavin adenine dinucleotide dependent glucose dehydrogenase. With these materials, each sensor only costs $0.40 to print and use. Before testing the 3D printed sensor, a suitable design, voltage range, and redox probe concentration were determined. Experiments demonstrated that this novel 3D printed sensor can accurately correlate current output to glucose concentration. It was verified that the sensor can accurately detect glucose levels from 25 mg/dL to 400 mg/dL, with an R2 correlation value as high as 0.97, which was critical as it covered hypoglycemic to hyperglycemic levels. This demonstrated that a 3D-printed sensor was created that had characteristics that are suitable for clinical use. This will allow diabetics to print their own test strips at home at a much lower cost compared to SMBG strips, which will reduce noncompliance due to the high cost of testing. In the future, this technology could be applied to additional biomarkers to measure and monitor other diseases.
ContributorsAdams, Anngela (Author) / LaBelle, Jeffrey (Thesis advisor) / Pizziconi, Vincent (Committee member) / Abbas, James (Committee member) / Arizona State University (Publisher)
Created2017
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Description

The purpose of this study is to collect baseline internal and external pressure data for the three most commonly used pelvic circumferential compression devices (PCCD). Unstable pelvic fractures as a result of automobile accidents, falls, and other traumatic injuries mortality rate [3]. Early use of pelvic circumferential compression devices can

The purpose of this study is to collect baseline internal and external pressure data for the three most commonly used pelvic circumferential compression devices (PCCD). Unstable pelvic fractures as a result of automobile accidents, falls, and other traumatic injuries mortality rate [3]. Early use of pelvic circumferential compression devices can mitigate fatal outcomes [4]-[5]. Prolonged eternal pressure above 9.3kPa can result in long-term soft tissue damage and pressure ulcers [7]. This study hypothesizes that the application of the three most commonly used PCCDs would result in the same mean maximum point pressure exertion. To study this, internal and external, both analog and digital, pressure apparati were used to collect data. The results of this data collection demonstrate a discrepancy in the pressure distribution between right and left greater trochanters within each PCCD. Additionally, the results suggest there is an effect of internal packing on the pressure exertion externally at the two greater trochanters within each PCCD. Lastly, the differences in pressure exertion between each PCCD, internally and externally, were inconclusive as some compared metrics resulted in statistically significant results while others did not. The methodologies employed in this study can be improved through fixation of pressure collection instruments, utilization of digital pressure mats, and removal of confounding factors. The results of this study indicate that digitized, discrete data over a fixed time interval may be clinically useful, suggesting that a digital data collection would yield more reliable data. Additionally, internally mounted pressure sensor data will provide more precise results than the analog method employed herein, as well as provide insight towards bone reduction and displacement following the application of PCCDs. Finally, the information gathered from this study can be utilized to improve upon existing technologies to create a more innovative solution.

ContributorsMoore, Kameron James (Co-author) / Dewald, Alison (Co-author) / Pizziconi, Vincent (Thesis director) / Bogert, James (Committee member) / Harrington Bioengineering Program (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

The purpose of this study is to collect baseline internal and external pressure data for the three most commonly used pelvic circumferential compression devices (PCCD). Unstable pelvic fractures as a result of automobile accidents, falls, and other traumatic injuries mortality rate [3]. Early use of pelvic circumferential compression devices can

The purpose of this study is to collect baseline internal and external pressure data for the three most commonly used pelvic circumferential compression devices (PCCD). Unstable pelvic fractures as a result of automobile accidents, falls, and other traumatic injuries mortality rate [3]. Early use of pelvic circumferential compression devices can mitigate fatal outcomes [4]-[5]. Prolonged eternal pressure above 9.3kPa can result in long-term soft tissue damage and pressure ulcers [7]. This study hypothesizes that the application of the three most commonly used PCCDs would result in the same mean maximum point pressure exertion. To study this, internal and external, both analog and digital, pressure apparati were used to collect data. The results of this data collection demonstrate a discrepancy in the pressure distribution between right and left greater trochanters within each PCCD. Additionally, the results suggest there is an effect of internal packing on the pressure exertion externally at the two greater trochanters within each PCCD. Lastly, the differences in pressure exertion between each PCCD, internally and externally, were inconclusive as some compared metrics resulted in statistically significant results while others did not. The methodologies employed in this study can be improved through fixation of pressure collection instruments, utilization of digital pressure mats, and removal of confounding factors. The results of this study indicate that digitized, discrete data over a fixed time interval may be clinically useful, suggesting that a digital data collection would yield more reliable data. Additionally, internally mounted pressure sensor data will provide more precise results than the analog method employed herein, as well as provide insight towards bone reduction and displacement following the application of PCCDs. Finally, the information gathered from this study can be utilized to improve upon existing technologies to create a more innovative solution.

Created2021-05
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Description
This thesis aims to incorporate exosomes into an electrospun scaffold for tissue engineering applications. The motivation for this work is to develop an implant to regenerate tissue for patients with laryngeal defects. It was determined that it is feasible to incorporate exosomes into an electrospun scaffold. This addition of exosomes

This thesis aims to incorporate exosomes into an electrospun scaffold for tissue engineering applications. The motivation for this work is to develop an implant to regenerate tissue for patients with laryngeal defects. It was determined that it is feasible to incorporate exosomes into an electrospun scaffold. This addition of exosomes does alter the scaffold properties, by decreasing the average fiber diameter by roughly a factor of three and increasing the average modulus by roughly a factor of two. Cells were cultured on a scaffold with exosomes incorporated and were found to proliferate more than on a scaffold alone. This research lays the groundwork for further developing and optimizing an electrospun scaffold with exosomes incorporated to elicit a tissue regenerative response.
ContributorsKennedy, Maeve (Author) / Pizziconi, Vincent (Thesis director) / McPhail, Michael (Committee member) / School of International Letters and Cultures (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05