Figure 6.

Fits for bond graph (BG) parameters against corresponding gating equations from the Luo–Rudy (LRd) model. Steady-state open probabilities are shown on the left panels, and time constants are shown on the right. The bond graph equations are plotted with solid lines, and the Luo and Rudy equations in dashed lines. Gates include (a) m, sodium activation; (b) h, sodium inactivation; (c) j, slow sodium inactivation; (d) K1, time-independent K⁺ activation; (e) X, time-dependent K⁺ activation; (f) ${\mathrm{X}}_{\mathrm{i}}$, time-dependent K⁺ inactivation; (g) Kp, plateau K⁺ activation; (h) d, L-type Ca²⁺ channel activation. Note that the ${\text{X}}_{\mathrm{i}}$ and Kp gates were originally formulated as steady-state equations, thus time constants are shown only for matched bond graph parameters.