Figure 5.

Phase loops and calculation of phase angle. Calculation of phase was performed using time-embedding methods. A two-dimensional state space was reconstructed from [F(t), F(t+τ)].¹⁸ A: Sample trace of a fluorescence V_m signal recorded during ventricular fibrillation (VF). B: Phase loops derived from an interval of VF with large-amplitude V_m oscillations. Phase trajectory consisted of loops rotating clockwise around the origin (red ρ). C: Phase loops derived from an interval of V_m oscillations with small, irregular amplitudes. Note that phase loops fell often outside the origin (red ρ). Time delay (τ) was set to 12 ms.¹⁸