INTELLIGENT WEARABLE OPTICAL SENSING: MULTIMODAL, MULTICHANNEL, AND MULTI-WAVELENGTH APPROACHES FOR ADVANCED PHYSIOLOGICAL MONITORING

Wearable optical sensing holds significant promise for personalized medicine, yet its translation to robust, real-world applications is hindered by fundamental limitations. This dissertation, "Intelligent Wearable Optical Sensing: Multimodal, Multichannel, and Multi-Wavelength Approaches for Advanced Physiological Monitoring," confronts critical barriers in non-invasive sensing, including superficial light penetration, signal corruption from motion, low spatial resolution, and biochemical non-specificity. This work presents a series of advanced, skin-interfaced optical systems that integrate novel hardware design with intelligent computational methods to achieve new sensing capabilities.To access deeper physiological information, a novel interface utilizing biocompatible microneedle waveguides is introduced, creating a photonic pathway that bypasses superficial tissue to enable reliable deep-tissue oximetry monitoring. To address the challenges of ambulatory use and complex signal interpretation, multimodal and multichannel systems are developed. One such system fuses optical data with inertial measurements, employing a computational architecture to effectively isolate true laryngeal muscle activity from motion artifacts. Another platform, a high-resolution optical myography array, generates detailed spatiotemporal maps of muscle dynamics. This system leverages advanced data-processing techniques to interpret complex gestures, enabling robust human-machine interaction. Finally, to move beyond conventional oximetry, a multi-wavelength spectroscopic sensor performs real-time, non-invasive quantification of a specific blood analyte. By optically deconvolving the unique spectral signature of ethanol from capillary blood, this wrist-worn device demonstrates a viable pathway toward direct, continuous monitoring of blood biochemistry.Overall, the investigations in this dissertation demonstrate effective solutions to long-standing barriers in wearable optical sensing. By thoughtfully combining advancements in optical interfacing, sensor dimensionality, and signal processing, this work delivers a validated toolkit of new sensing strategies. These contributions lay the groundwork for a new generation of reliable, non-invasive devices for personalized diagnostics, advanced assistive technologies, and more intuitive human-machine interfacing.