TissOP-Probe: An Integrated Measurement–Modeling Framework for Translating Ex Vivo Tissue Optical Properties into Diffuse Reflectance Probe Design Specifications

Adequate understanding of tissue optical characteristics is the foundation of laser-based diagnostics and phototherapy. This paper introduces an integrated experimental-computational-engineering framework for laser-based characterization of biological tissues, bridging the gap between biophysical measurement and medical device design. Ex vivo tissues, including chicken skin (native, boiled, dry), chicken liver (native, coagulated), bovine muscle, and rabbit skull, were measured at clinically relevant wavelengths (635, 650, and 808 nm) using both integrating sphere and distant-detector configurations. Parameters were extracted using the Kubelka–Munk model and the Beer–Lambert law. The Diffusion Approximation, which was solved using the Finite Element Method in COMSOL Multiphysics, was used to generate high-resolution fluence rate distributions. Typical engineering design criteria for diffuse reflectance probe systems, such as optimal source–detector separation, fiber numerical aperture, operating wavelength selection, and an exploratory ex vivo tissue-state index (CDI) whose in vivo applicability remains to be established, are subsequently obtained from the resulting optical property database. The proposed method shows how the hardware design of non-invasive biomedical sensing devices is influenced directly and optimized by a systematic optical characterization workflow, which minimizes empirical trial-and-error in prototype development. This multidisciplinary approach offers a consistent methodology that may be used with image-guided surgical equipment, phototherapy planning systems, and optical biopsy probes.