NONINVASIVE CHARACTERIZATION OF OTITIS MEDIA WITH IMAGE-GUIDED RAMAN SPECTROSCOPY

Abstract

Otitis Media (OM), an inflammatory disease of the middle ear, is the most common pediatric diagnosis and the leading cause of outpatient antibiotic use for children. It is a complex disease that progresses through unique phases with varying severity. Overlapping symptomologies between different forms of OM cause challenges in proper diagnosis and treatment. Current methods to diagnose OM rely on visual inspection of the eardrum, resulting in low diagnostic accuracy and inappropriate prescription of antibiotics. This work summarizes an effort toward the pre-clinical translation of Raman Spectroscopy (RS), an inelastic light scattering technique, to noninvasively identify spectral signatures related to OM. Initial in vivo RS feasibility measurements collected from children presenting with OM were first evaluated, which prompted a component-level characterization of middle ear components using a physiologically relevant in vitro model. To address the identified optical design challenges in implementing an RS system specific for clinical use, technological development of the RS system was conducted to minimize the acquisition time of measurements to promote clinical adoption. A noncontact fiber optic probe was fabricated with image guidance features to measure spatially-specific signals in the ear. This RS device is designed to measure both fingerprint (FP) and high-wavenumber (HW) regions of the Raman spectrum, as each region provides unique but complimentary chemical signatures to identify the presence and composition of middle ear fluid that accumulates during OM. Finally, the optimized RS system was utilized in a clinical feasibility study to understand the operational requirements for applying RS within the middle ear. Results demonstrate that RS can detect the presence of middle ear fluid with 93% accuracy, and can differentiate fluid type with 76-86% accuracy.