Depth-Sensitive Optical Property Characterization Using Multi-Frequency Laparoscopic SFDI
Journal:
bioRxiv
Published Date:
Feb 6, 2026
Abstract
Accurate knowledge of tissue absorption () and reduced scattering (s'), parameters is required to plan and monitor laparoscopic chemophototherapy (CPT) in ovarian cancer, including light dosimetry and quantitative fluorescence mapping of porphyrin phospholipid (PoP) photobleaching and light triggered doxorubicin (Dox) release. We implemented a depth-sensitive, multi frequency laparoscopic spatial frequency domain imaging (SFDI) framework to improve optical-property estimation in layered tissue. A DMD based laparoscope imaged two layer phantoms with controlled optical contrasts and superficial thicknesses. Spatial-frequency subsets associated with different penetration depths were independently fit to recover and s', and compared with a two layer diffusion model. Recovered s' values remained bounded by the known layer references and shifted monotonically toward the superficial value as spatial frequency and top layer thickness increased, approaching a single layer response at high frequency/thick layers. Quantitative model comparison showed {delta}-P1 variants outperformed the standard diffusion approximation, reducing RMSPE between modeled and measured s' to 0.8-6.5% (silicone/silicone) and 1.6-8.3% (silicone/intralipid), whereas SDA errors reached ~13.8% and 21.1%, respectively. This approach demonstrates multi frequency laparoscopic SFDI as a practical initial step for depth sensitive fluorescence correction for individualized CPT treatment planning and monitoring.
