Fig. 6.

(a) Estimation of coagulation thickness through piecewise linear regression against static scattering isolevels, L, utilizing the increasing depth penetration of the light with increasing distance from the laser line. (b) Estimation of coagulation thickness from least-squares fitting to a logarithmic function of the static scattering, S, at the center of the laser line, corresponding to a traditional LSI measurement without depth resolution. The fitting works well for a wedge thickness up to about 1.5 mm (at x around 25 mm), but when the wedge gets thicker, the fitting becomes much less accurate than when using the longer distances from the laser line where the signal comes from light that has travelled deeper.