Real-time and accurate estimation ex vivo of four basic optical properties from thin tissue based on a cascade forward neural network.

Double integrating sphere measurements obtained from thin tissues provides more spectral information and hence allows full estimation of all basic optical properties (OPs) theoretically. However, the ill-conditioned nature of the OP determination increases excessively with the reduction in tissue thickness. Therefore, it is crucial to develop a model for thin tissues that is robust to noise. Herein, we present a deep learning solution to precisely extract four basic OPs in real-time from thin tissues, leveraging a dedicated cascade forward neural network (CFNN) for each OP with an additional introduced input of the refractive index of the cuvette holder. The results show that the CFNN-based model enables accurate and fast evaluation of OPs, as well as robustness to noise. Our proposed method overcomes the highly ill-conditioned restriction of OP evaluation and can distinguish the effects of slight changes in measurable quantities without any knowledge.