Q-sensing Method for Superficial Scattering Extraction

Biomedical optic systems provide rapid, non-invasive, and cost-effective solutions for diagnosing health conditions such as skin cancer. These conditions are influenced by optical properties, scattering and absorption, as well as by the different layers of the skin. The complexity of tissues makes it challenging to identify changes in specific layers and differentiate between their influences. Hence, we propose using the Q-sensing technique, which leverages polarized light to isolate superficial scattering from diffuse background signals, enabling the measurement of scattering coefficient and distinguishing layer contributions. By measuring co-polarized (I_||) and cross-polarized (I_⊥) light, we utilize the Q parameter as it highlights superficial scattering. In our study, experiments were conducted with tissue-mimicking phantoms of varying thicknesses and scattering properties, validated through Monte Carlo simulations. The results demonstrate that depolarization stabilizes at specific values determined by the material's properties, allowing accurate estimation of the material’s scattering properties. The Q-sensing approach improves the characterization of optical properties in complex tissues, offering a reliable tool for non-invasive diagnostics.