Publication Date

2020

Document Type

Thesis

Committee Members

Ulas Sunar, Ph.D. (Advisor); Tarun Goswami, D.Sc. (Committee Member); Josh Ash, Ph.D. (Committee Member)

Degree Name

Master of Science in Biomedical Engineering (MSBME)

Abstract

Optical imaging has demonstrated potential as a medical imaging modality for measuring tissue functionality. Recently, interest in fluorescence guided surgery has emerged from improvements in optical imaging that have allowed real-time feedback. Of the optical imaging modalities, spatial frequency domain imaging (SFDI) has gained a lot of interest. Unlike spectroscopic techniques, such as functional near infrared spectroscopy (fNIRS) and frequency domain spectroscopy that measure bulk tissue properties, SFDI quantifies tissue functionality locally and wide field making it practical for clinical applications. Unfortunately, traditional SFDI systems use multi-pixel detectors, which may not exhibit ideal spectral characteristics, have limited sensitivity, be expensive, or bulky in size. On the other hand, avalanche photodiodes (APD) and single photon counting modules (SPCM), are much more sensitive to the spectrum ideal for optical imaging, inexpensive, and compact in size. Traditionally, an array of photodiodes are required to capture an image, but with the advent of single pixel cameras entire images can be captured with a single photodiode. In this thesis, a novel single pixel camera (SPC) is used to capture an image of the light field projected by an SFDI system to explore its feasibility as a detection method relative to a traditional charged-coupled device (CCD) or scientific complementary metal-oxide semiconductor (sCMOS) camera. To determine the feasibility of single pixel SFDI, both sCMOS and SPC SFDI implementations were built to measure the optical properties of a brain tissue simulating phantom. In the results chapter, the mean optical scattering and absorption properties are reported for regions of high and low optical absorption indicating single pixel camera spatial frequency domain imaging (SPC SFDI) is viable given certain applications. In Chapter 1, I provide the motivation and significance of single pixel spatial frequency domain imaging (spSFDI) in a clinical setting of neurological disease. Chapter 2 consists of theory and methods behind spSFDI. Chapter 3 covers the instrumentation setup and results from our tissue simulating phantom experiments. Finally, Chapter 4 concludes with final thoughts on the application space of spSFDI and methods to improve its implementation. From our phantom experiment results, spSFDI demonstrates it can obtain optical properties within 10 percent error, which is comparable to traditional SFDI instrumentation. This method is expected improve optical parameter quantification and have further applications in fNIRS research field related to diagnosis and therapy monitoring.

Page Count

64

Year Degree Awarded

2020


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