Optical properties of the tissue effects upon the dynamic spectrum

In the research of non-invasive concentration blood measurement, the scattering behavior of the tissue may leads to significant differences in the ideal Lambert Beer's law. In this paper, Monte Carlo method is used to analyses the blood tissue's influence to the Dynamic Spectrum proposed by Professor LI Gang. The Dynamic Spectrum evaluating only the pulsatile part of the entire optical signal, this approach is rather independent of individual or time changes in scattering or absorption characteristics of the tissue. In this paper, Monte Carlo method is used to analyses the scattering behavior of the blood, the influence of the scattering behavior of the skin tissue to the scattering behavior of the blood. and their influence to the Dynamic Spectrum. The pulsatile part of the spectrum was modeled by performing simulations of photon migration through the tissue for the diastolic and systolic states. With the simulation of the Monte Carlo method, the diffuse reflectance and transmittance of the model was calculated., analyzed and compared. The scattering behavior must be considered in the measurement of Dynamic Spectrum to get the high precision measurement. The error caused by the transmittance is greater than the error caused by the diffuse reflectance. The thickness of the Epidermis can influence the nonlinearity of the transmittance, and influence the value of the diffuse reflectance. The thickness of the tissue can influence the scattering behavior of the tissue.