BME PhD Dissertation Defense: Aarohi Mehendale

Title: "Spatial Frequency Domain Imaging (SFDI) for Scleroderma Skin Assessment"

Advisory Committee: Darren Roblyer, PhD - BU BME (Advisor) Irving Bigio, PhD - BU BME (Chair) Jerome Mertz, PhD - BU BME Andreea Bujor, MD, PhD - BUMC Rheumatology Vasan Venugopalan, PhD - UC Irvine, Chemical and Biomolecular Engineering

Abstract: Scleroderma, or systemic sclerosis (SSc) is a chronic, autoimmune disorder, characterized by skin and internal organ fibrosis. The extent and progression of skin involvement is a predictor for future organ complications and survival. Accurately assessing the degree of skin thickening in patients with SSc is of vital importance, but the current clinical standard pinch score suffers from limitations including subjectivity, bias and unreliability. There is hence a need for a reliable, objective and quantitative metric to assess skin involvement in scleroderma. This work proposes Spatial Frequency Domain Imaging (SFDI), a non-invasive, wide-field diffuse optical technique as a method to track skin involvement in scleroderma. First, we demonstrate the clinical validity of this technique. Then, to advance SFDI towards a usable research and clinical device for SSc, we explore methods to simplify acquisition. This includes proposing Structured Light Imaging Mesoscopy, a method that uses diffuse reflectance measurements at specific imaging parameters that allows for the tuning of depth sensitivity, and proposing a novel method to perform SFDI measurements using a spiral pattern, which significantly reduces device footprint. This work aims to propose a quantitative, reliable measure of skin involvement in scleroderma and develop methods to ensure its deployment in clinic and research studies.