Fig. 1.

Optical parameters of the human blood at 840 nm as functions of the HCT. (A) Scattering coefficient${\mu }_s$. The black solid line is based on Twersky's formula [30] and the red dash line is based on the empirical model function in [32]. (B) Absorption coefficient${\mu }_a$. (C) Effective scattering coefficient${\mu }_s^{\prime }$. (B) and (C) are both based on the empirical model functions in [32].