Publication Date
2019
Document Type
Thesis
Committee Members
Ulas Sunar, Ph.D. (Advisor); Keiichiro Susuki, Ph.D. (Committee Member); Mary Fendley, Ph.D. (Committee Member)
Degree Name
Master of Science in Biomedical Engineering (MSBME)
Abstract
Near infrared spectroscopy (NIRS) is a non-invasive technique that uses near-infrared light and hemoglobin as the contrast to characterize tissue optical properties, namely optical absorption [����] and scattering [����′ ]. Through this characterization, it is possible to obtain information about the tissue’s oxygenated (HbO) and deoxygenated (Hb) hemoglobin concentrations and oxygen saturation which are important physiological markers for diagnosis and intervention monitoring. Many commercial devices use a continuous wave approach (CW-fNIRS), a technique that simply relies on intensity changes from a constant power laser to determine only relative changes in oxygenation. This is a significant limitation for clinical settings where there is a need for assessing absolute values of these parameters during monitoring of an intervention, lasting from weeks to months. For example, children with autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) go through behavioral, diet and medication-based therapies that can last several months. Thus, an absolute quantitative number can be a reliable metric to assess the changes induced by these longitudinal interventions in these populations. In this respect, a frequency-domain (FD) fNIRS approach is utilized to quantify absolute optical parameters. I will show the system and methods related to FD-fNIRS. Then I will show the experimental results from tissue-mimicking phantoms, cuff ischemia tests, and verification on Autism Model Mice. The results indicate that FD-fNIRS can quantify optical parameters within 10% error and can discriminate the contrasts between mice populations. In conclusion, FD-fNIRS can be useful technique for applications that require absolute contrasts and quantitative changes in contrasts.
Page Count
67
Department or Program
Department of Biomedical, Industrial & Human Factors Engineering
Year Degree Awarded
2019
Copyright
Copyright 2019, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.
