Determination of tissue optical properties from diffuse reflectance profiles by multivariate calibration

Area of Science:

• Biomedical Optics
• Biophysical Measurement Techniques

Background:

• Accurate optical properties (absorption and scattering coefficients) are crucial for understanding light propagation in biological tissues.
• Spatially resolved diffuse reflectance is a promising non-invasive technique for probing tissue optics.

Purpose of the Study:

• To develop and validate a robust method for determining the reduced scattering and absorption coefficients of turbid biological media.
• To assess the performance of the method under various practical conditions.

Main Methods:

• Utilized a Sugeno Fuzzy Inference System for multivariate calibration and prediction.
• Employed advanced data preprocessing, including principal component analysis and a diffusion theory-based curve-fitting procedure.
• Generated and analyzed reflectance data from Monte Carlo simulations.

Main Results:

• Achieved a root-mean-square error of 0.25% for both absorption and reduced scattering coefficients.
• Demonstrated the method's accuracy with absorption coefficients ranging from 0.04 to 0.06 mm⁻¹ and reduced scattering coefficients from 0.45 to 0.99 mm⁻¹.
• Evaluated the impact of relative vs. absolute reflectance, measurement noise, and detector configuration on prediction accuracy.

Conclusions:

• The proposed fuzzy inference system method provides a highly accurate approach for quantifying optical properties of biological tissues.
• The method is robust and its performance is well-characterized concerning practical measurement variations.