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. 2001 Apr 24;98(10):5827–5832. doi: 10.1073/pnas.091553398

Figure 4.

Figure 4

A segment of an alternans control trial (Patient 1). a, b, and c show AV, VA, and g vs. beat number n for various stages (as annotated in c) of the control trial. VA nonlinear-dynamical control perturbations terminated the alternans in each of the control attempts. The Insets in each panel show the first 15 beats of the second control attempt (1,290 ≤ n ≤ 1,305). During this time, the adaptive flexibility of the algorithm is apparent by means of the algorithmic modifications made to the AV steady-state estimate [a Inset, AV (filled circles) and AV steady-state estimate (open diamonds)] and to g (c Inset). The changes in g were dictated (as described in Methods and ref. 36) by every second beat (1,290 ≤ n ≤ 1,295) to every fourth beat (1,296 ≤ n ≤ 1,303) and back to every second beat (1,303 ≤ n ≤ 1,305) VA perturbation patterns (b Inset).