Figure 3
From: Mood regulation in bipolar disorders viewed through the pendulum dynamics concept
The Nyquist plot corresponds to an unstable system. (A) Nyquist plot indicating the stability margins of the mass pendulum system under unstable operation caused by a series of unexpected delays. (B) The plot focuses in the critical circle showing that −1 + j0 (red cross indicated by the arrow) is encircled by the trajectory line indicating thus the instability of the system. The multiple time-dependent feedback mechanism fails to recover the equilibrium.