Figure 3. Modeling the influence of sevoflurane on the bispectral index (BIS): best, median, and worst fits according to the coefficient of determination, given by¹⁰[Greek small letter rho]²= 1 - Sigma (BIS^measured- BIS^predicted)^2/Sigma(BIS^measured- mean[BIS^measured])²Corresponding model fits for spectral edge frequency (SEF) are included (smoothing rates are "off" and movement artifacts discarded).