The use of polarized light for characterization of biological tissues has received increased attention in recent years due to the wealth of information available in the interactions of polarized light with tissue and the noninvasive nature of optical radiation. While the depolarizing effects of multiple scattering complicate the use of polarimetry in tissue, many biological constituents affect the polarization of light such as collagen, muscle fibers, and glucose. Thus, if the effects of scattering can be accounted for⎯or utilized in the analysis⎯polarized light can potentially be used as a probe of tissue status.
This thesis presents advancements in the techniques for the simulation of polarized light in tissue-simulating media, and explores two biomedical applications. Previous Monte Carlo models for simulation of polarized light propagation in tissue-simulating media do not include the effects of birefringence and optical activity, two polarizing effects of useful diagnostic potential. To overcome this limitation, our model was extended to include both these effects simultaneously, and then experimentally validated using a novel polarization phantom system. The use of polarized light for characterization of the myocardium, and specifically towards monitoring stem cell regenerative treatments of myocardial infarction, was investigated experimentally as a novel application for polarimetry. The potential for this technique is based on the changes in myocardial structure that occur with infarction and subsequent regeneration, and the associated changes in tissue birefringence. The use of polarized light for noninvasive tissue analyte monitoring, particularly glucose, was also investigated based on the optical activity exhibited by many tissue analytes due to their chiral structure. In this study, a novel combined optical polarization and intensity approach was developed and tested on Monte Carlo simulated data. The studies presented in thesis introduce new methods for polarization simulation and analysis in biological tissue and demonstrate potential for polarimetry in monitoring myocardial regeneration and noninvasive measurements of tissue analytes.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/29915 |
| Date | 31 August 2011 |
| Creators | Wood, Michael Frank Gunter |
| Contributors | Vitkin, Alex |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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