Abstract: A system is provided for determining a level of alertness of a subject, using a physiological sensor for providing physiological sensor signals which distinguish between a sleep state and an awake state of the subject. Sleep sessions are identified and their associated falling asleep and waking up times. A single representative midsleep time is obtained from multiple sleep sessions over a 24 hour period, and a circadian phase is estimated using the single representative midsleep time. A level of alertness is then obtained from the circadian phase. This system avoids the need for the use of a default circadian phase when determining a level of alertness. The system can more accurately estimate sleepiness for individuals that have irregular sleep patterns such as shift workers or people with sleep disorders. The single representative midsleep time is also able to take account of multiple sleep sessions, i.e. naps or periods of restless sleep.

Abstract: A system and computer program are provided for computer aided diagnosis or monitoring of heart failure patients. The system and computer program obtain patient data representing measurements of a select and limited set of health indicators of a patient. A trained classifier is applied to the patient data to obtain a classification of the occurrence or degree of heart failure for the patient. The limited set of health indicators is specifically selected from a large set of health indicators which are known to be predictive of heart failure on the basis of a clinical study which demonstrated the accuracy of the classification using this select set.

Abstract: A lighting system comprises at least one luminaire arranged to illuminate an area shared by a plurality of users. From at least one of the users, at least one level adjustment instruction is received, denoting an illumination level instructed by that user for the shared area. When operating in a manual control mode for the shared area, the at least one luminaire is controlled to emit illumination at the illumination level denoted by the most recently received of the level adjustment instruction(s). A plurality of user profiles is generated, each of a respective one of the users and comprising preference information, wherein the preference information for the at least one user is derived from his at least one level adjustment instruction. A consensus illumination level for the shared area is determined, by combining the preference information of at least two of the user profiles stored in the memory.