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Description
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 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
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 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
Description
Lab-grown food products of animal cell origin, now becoming popularly coined as, ‘Cellular Agriculture’ is a revolutionary breakthrough technology that has the potential to penetrate the lives of every American or citizen of the world. It is important to recognize that the impetus for developing this technology is fueled by environmental concerns with climate change, rising geopolitical instability, and population growth projections, where farm-grown food has now become a growing national security issue. Notwithstanding its potential, in addition to the necessary technological innovation and economic scalability, the market success of cellular agriculture will depend greatly on regulatory oversight by multiple government agencies without which it can cause undue harm to individuals, populations, and the environment. Thus, it is critical for those appropriate United States governing bodies to ensure that the technology being developed is both safe and of an acceptable quality for human consumption and has no adverse environmental impact. As such, animal foods, derived from farms, previously regulated almost exclusively by the United States Department of Agriculture (USDA) are now being regulated under a joint formal agreement between the US Food and Drug Administration (US FDA) and the USDA if derived from the lab, i.e., lab-grown animal foods. The main reason for joint oversight between the FDA and the USDA is that the FDA has developed the in-house expertise to oversee primary cell harvesting and cell storage, as well as, cell growth and differentiation for the development of 3D-engineered tissues intended for tissue and organ replacement for the emerging field of regenerative medicine. As such, the FDA has been given the authority to oversee the ‘front end’ of lab-grown food processes which relies on the very same processes utilized in engineered human tissues to produce food-grade engineered tissues. Oversight then transitions to the USDA-FSIS (Food Safety and Inspection Service) during the harvesting stage of the cell culture process. The USDA-FSIS then oversees the further production and labeling of these products. Included in the agreement is the understanding that both bodies are responsible for communicating necessary information to each other and collaboratively developing new regulatory actions as needed. However, there currently lacks clarity on some topics regarding certain legal, ethical, and scientific issues. Lab-grown meat products require more extensive regulation than farm-grown animal food products to ensure that they are safe and nutritious for consumption. To do this, CFSAN can create new classes of lab-grown foods, such as ‘lab-grown USDA foods,’ ‘lab-grown non-USDA foods,’ ‘lab-grown extinct foods,’ ‘lab-grown human food tissues,’ and ‘medically activated lab-grown foods.’
ContributorsBanen, Samuel (Author) / Pizziconi, Vincent (Thesis director) / Feigal, David (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor) / School of Molecular Sciences (Contributor)
Created2023-05
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 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
Description
The adaptive artificial-intelligence (AI) medical device industry is a novel industry in the United States offering innovations to the healthcare field. The rapid expansion of this industry in recent years has drawn attention from multiple stakeholders causing a heated debate about how to introduce these innovations into the market while maintaining patient safety and treatment efficacy. Since early 2019, the U.S. Food and Drug Administration (FDA) has been releasing statements in regards to the improvement of regulation for this new technology, but has yet to take further actions. Dilemmas including 1) a difficult regulatory process, 2) a heightening financial burden and 3) looming liability issues, are reasons adaptive AI medical devices have struggled to be advanced. By conducting a thorough analysis of these 3 issues, recognizing the intricacies of them separately and together, this study develops a better understanding of the landscape adaptive AI technology is facing and provides a clearer picture for the future of the industry.
ContributorsOgden, Ravyn Nicole (Author) / Coursen, Jerry (Thesis director) / Pizziconi, Vincent (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Homeopathy is a brand of alternative medicine that has enjoyed a unique form of regulation for many years. This work aims to understand the regulation of homeopathic drugs in the United States by performing a literature review focused on three fronts: (i) homeopathy (theory, history in the United States and criticisms), (ii) U.S Food and Drug Administration (history and relationship to homeopathy), and (iii) interpretation of the law through reading guidance documents and the Code of Federal Regulations.
In 2015, the FDA began a process to reevaluate and update the regulations surrounding homeopathic products to better fit their present risk-based model. Past regulations were set in 1938; and as the world evolved, these have been found to set inadequate standards. By reviewing the agency’s guidance drafts and core regulatory documents, we come to understand that these changes are motivated by a desire for homeopathic remedies to follow high standards that apply to other products for the benefit of the U.S. consumers. FDA has made significant advances by proposing new Guidances on homeopathic products, listening to homeopathic community and consumers, and withdrawing the Compliance Policy Guide 400.400 issued in 1988.
We recommend for homeopathic manufacturers and practitioners to see the FDA as an ally and cooperate fully with the proposed changes for the regulation the agency gives out. Doing so will give the homeopathic community the best chance at continuing to sell their products and reach their consumers in the United States. In the same token, the FDA should do their best to involve homeopathic professionals in some way in this regulatory process, to encourage participation and compliance by the broader homeopathic community. Doing so ensures a climate of teamwork among different facets of the medical community in the United States.
In 2015, the FDA began a process to reevaluate and update the regulations surrounding homeopathic products to better fit their present risk-based model. Past regulations were set in 1938; and as the world evolved, these have been found to set inadequate standards. By reviewing the agency’s guidance drafts and core regulatory documents, we come to understand that these changes are motivated by a desire for homeopathic remedies to follow high standards that apply to other products for the benefit of the U.S. consumers. FDA has made significant advances by proposing new Guidances on homeopathic products, listening to homeopathic community and consumers, and withdrawing the Compliance Policy Guide 400.400 issued in 1988.
We recommend for homeopathic manufacturers and practitioners to see the FDA as an ally and cooperate fully with the proposed changes for the regulation the agency gives out. Doing so will give the homeopathic community the best chance at continuing to sell their products and reach their consumers in the United States. In the same token, the FDA should do their best to involve homeopathic professionals in some way in this regulatory process, to encourage participation and compliance by the broader homeopathic community. Doing so ensures a climate of teamwork among different facets of the medical community in the United States.
ContributorsRobayo, Juan Pablo (Author) / Pizziconi, Vincent (Thesis director) / Feigal, David (Committee member) / Frow, Emma (Committee member) / School of International Letters and Cultures (Contributor) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05