Minimum root mean squared error piecewise linear fits to the coefficients of the Resonant model (RM) of a human sinoatrial node cell at different levels of I_f blockage.

The black diamonds represent the RM coefficients obtained after fitting to AP waveshapes of Fabbri et al. model for specific percentage values of I_f blockage. Dotted lines represent the piecewise linear fits to the coefficients. Different colors represent different linear equation fits. Coefficients of every oscillator in the RM are placed together in a black rectangular box. ω represents the fundamental frequency.