Using MAP to recover the optical properties of a biological tissue from reflectance measurements

摘要

There exist numerous methods that aim to extract the optical parameters of a tissue by relating reflectance measurements to a theoretical model of light transport. During the parameter recovery process, assumptions are often made about the characteristics of the tissue. However, specious assumptions lead to inaccurate or even incorrect results. We present a method based on the maximum a posteriori estimation technique to recover the concentrations of the main chromophores present in a biological tissue from reflectance or transmittance measurements. The method provides correct results even in the presence of significant uncertainty in the underlying properties of the tissue. A preliminary analysis of the results obtained from simulated skin reflectance spectra suggests that the proposed MAP based method provides accurate estimates and is robust against a high level of uncertainty in the tissue's model. The results of phantom data are in agreement with the findings from our simulations as they emphasise the importance of including prior information about the unknown parameter in the estimation process