Abstract: A method of electronically monitoring a subject, for example in a home care environment, to determine the presence of the subject in zones of the environment as a function of time includes fusing data from image and wearable sensors. A grid display for displaying the presence in the zones is also provided.

Abstract: A reflective photoplethysmograph sensor (for example mounted in an earpiece) arranged for photoplethysmograph measurements behind a subject's ear is provided. Also provided is a wearable photoplethysmograph heart rate sensor which includes a plurality of radiation detectors defining respective sensing planes which are tilted with respect to each other. Further there is provided a photoplethysmograph heart rate sensing system which compensates for motion artefacts using a dark signal which may be derived during an off phase of a duty cycle of an emitter and a photoplethysmograph system arranged to select between a plurality of detectors based on a quality measure. Combinations of the systems and sensors are also disclosed.

Abstract: A method of classifying a data record as belonging to one of a plurality of classes, the data records comprising a plurality of data samples, each sample comprising a plurality of features derived from a value sampled from a sensor signal at a point in time, the method including: defining a selection variable indicative of the temporal variation of the sensor signals within a time window; defining a selection criterion for the selection variable; comparing a value of the selection variable to the selection criterion to select an input representation for a self organising map, the map having a plurality of input and output units, and deriving an input from the data samples within the time window in accordance with the selected input representation; and applying the input to a self organising map corresponding to the selected input representation and classifying the data record based on a winning output unit of the self organising map.