Development and Optimization of an Integrated Faraday Modulator and Compensator Design for Continuous Polarimetric Glucose Monitoring

In recent years, significant advances have been made in the development of noninvasive polarimetric glucose detection systems, salutary for the treatment of our rapidly increasing diabetic population. This area of research utilizes the aqueous humor as the detection medium for its strong correlation to blood glucose concentration and highlights three major features: the optical activity of glucose, minimal scattering of the medium, and the ability to detect sub-millidegree rotation in polarized light. However, many of the current polarimetric systems are faced with size and cost constraints based on the paramount optical components (e.g., terbium gallium garnet or terbium doped glass) and custom wound inductive coils. As a step toward developing a low cost hand-held design, a miniaturized integrated single-crystal Faraday modulator/compensator (IFMC) has been designed and optimized. This device is capable of replacing the traditional two component arrangement that has been widely reported on in many Faraday-based polarimetric configurations.In this work, an electromagnetic (EM) finite element model (FEM) was developed that can simulate various physical parameters such as geometry, inductance, and orientation of an IFMC with respect to the optical components in order to minimize power consumption and size while maintaining appropriate magnetic field strength. The newly designed prototype was compared with the FEM, providing excellent correlation with operational performance shown to be within 1.8% of predicted values. It was shown that the use of FEM simulations allows for the analysis of a vast range of parameters before prototypes are fabricated and can facilitate custom designs as related to development time, anticipated performance, and cost reduction. Furthermore, the performance of the IFMC was evaluated experimentally under both noninvasive static and dynamic glucose monitoring conditions with a custom designed glucose flow system. The dynamic flow system provides a repeatable and controllable testing environment which can recreate in vivo glucose profiles while reducing the need for repetitive, expensive, and time consuming animal experiments. Finally, it was shown that the combined rotator can achieve modulation depths above 1°, and when operating in a compensated closed-loop configuration, it had demonstrated glucose prediction errors of 1.8 mg/dL and 5.4 mg/dL under hypoglycemic and hyperglycemic conditions, respectively. These results demonstrate that such an integrated design can perform similar to, if not better than, its larger two-part predecessors. Overall, this technology is capable of expediting future research and development in providing a fully functional and commercially available noninvasive polarimetric glucose sensor.

Name thesis:degree_name

Master of Science in Bioengineering

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Bioengineering

Grantor dc:publisher

University of Toledo

Year dc:date

2013

Author dc:creator

• Clarke, Brandon William

Contributors dc:contributor

• Cameron, Dr. Brent D.

• Biomedical Engineering
• Biomedical Research
• Engineering
• Optics
• optical polarimetry
• noninvasive glucose sensing
• integrated Faraday modulator and compensator (IFMC)
• diabetes
• continuous monitoring
• flow system
• optical modulation
• magnetic field
• finite element model (FEM)
• terbium gallium garnet (TGG)
• inductors

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=toledo1364578141

OAI identifier oai:identifier

oai:etd.ohiolink.edu:toledo1364578141