Showing papers by "Martin Ouwerkerk published in 2015"

Circadian phase detection system

Abstract: The present invention relates to a device (10) for detecting a circadian phase shift of a user (48). The device comprises: an interface for obtaining a skin conductance signal of the user (48) and sleep cycle information of the user (48); a processing unit (14) for determining an internal clock wake-up time based on the obtained skin conductance signal (20) and an external clock wake-up time based on the obtained sleep cycle information; and an evaluation unit (16) for evaluating a circadian phase shift of the user (48) based on the internal clock wake-up time and the external clock wake-up time. The present invention further relates to a corresponding method as well as to a wearable system (22) for monitoring a circadian phase shift of a user (48).

Method of operating system for determining physiological condition of person

Abstract: PROBLEM TO BE SOLVED: To provide a method of operating a system for promptly determining a coherent condition of a person.SOLUTION: At least one sensor 102 samples a plurality of heart beats of the person, a control unit 106 extracts a series of cardiac RR intervals from the heart beat samples, and a Poincare plot of subsequent RR intervals is provided, wherein two continuously occurring RR intervals form an entry in the Poincare plot. A centroid is determined for a plurality of entries within the Poincare plot, and an ellipse or a circle is fitted over the plurality of entries within the Poincare plot. A center of the ellipse or the circle is matched with the centroid, distances between the ellipse or the circle and the plurality of entries within the Poincare plot are determined and it is determined whether all the determined distances are settled within a predetermined first threshold, thereby determining whether the person is coherent.