Abstract: A method for determining a zeitgeber, K(t), for use in a circadian entrainment system to entrain an individual's circadian clock from a current circadian trajectory, x(t), towards a target circadian trajectory, y(t), can reduce a cost function C=C(x(t), y(t), K(t)) given an initial circadian state, x0, and y(t), by (a) providing an initial zeitgeber, K0(t), setting K(t)=K0(t), (b) simulating x(t) in response to K0(t), (c) computing a global cost function, C(x(t), y(t), K0(t)), based on the simulation, (d) determining whether the global cost function meets a set of convergence criteria, and if not, (e) updating K(t) based on the global cost function, (f) updating the global cost function based on the updated zeitgeber K(t), (g) iterating until the global cost function meets the convergence criteria, and (h) providing the updated zeitgeber K(t) for use in the circadian entrainment system to entrain the individual's circadian clock.

Abstract: A goal of this invention is to minimize the cost of shifting a circadian state or entraining a state to a target cycle by identifying a preferred zeitgeber stimulus. Another goal of this invention is to provide a method to determine a person's circadian state trajectory given a stimulus time series.