Methodology development and evaluation of optical properties characterisation of small size tissue samples

• Main Authors: Xie, Yijing, Shapey, Jonathan, Nabavi, Eli, Li, Peichao, Bahl, Anisha, Ebner, Michael, Vercauteren, Tom
• Format: Journal Article
• Language: English
• Published: 10.07.2021
• Subjects: Physics - Biological Physics; Physics - Medical Physics; Physics - Optics
• DOI: 10.48550/arxiv.2107.04909

Integrating sphere (IS) techniques combined with an inverse adding doubling (IAD) algorithm have been widely used for determination of optical properties of ex vivo tissues. Semi-infinite samples are required in such cases. The aim of this study is to develop a methodology for calculating the optical absorption and reduced scattering of biological tissues of small size from IS measurements at 400-1800 nm. We propose a two-stage IAD algorithm to mitigate profound cross-talk effects in the estimation of the reduced scattering in the case of very high absorption. We developed a small sample adaptor kit to allow IS measurements of samples with small sizes using a commercial spectrophotometer. Results showed that: The two-stage IAD substantially eliminated the cross-talks in the reduced scattering spectra, thus rectifying absorption accordingly; and the small sized sample measurements led to systematically overestimated absorption values while the spectrum shape well preserved as compared to the normal port size measurements.