Characteristic changes in brain activity accompany the paradoxical increase in alertness observed in some patients with severe brain injury when they are treated with the sleeping pill zolpidem.

In this letter note we present two new parameter identifiers whose estimates converge in finite time under weak interval excitation assumptions. The main novelty is that, contrast with other finite-convergence (FCT) estimators, our schemes preserve the FCT property when parameters change. previous versions of estimators can track variations only asymptotically. Continuous-time and discrete-time...