Unobtrusive remote monitoring device for extracting information from detected characteristic signals, comprising: - an interface for receiving a data stream (76, 78, 80, 82) comprising a sequence of image frames derivable from electromagnetic radiation emitted or reflected by an object and detected by a sensor means, the sequence of image frames comprising a continuous or discrete characteristic signal including physiological information, the physiological information being representative of at least one at least partially periodic vital signal, - an extractor means for extracting the physiological information from the data stream (76, 78, 80, 82), the extractor means deriving a plurality of characteristic index elements from the data stream (76, 78, 80, 82), the plurality of characteristic index elements being indicative of the physiological information and a disturbing signal component, wherein the plurality of characteristic index elements is associated with a signal space representative of characteristics of the electromagnetic radiation, the signal space comprising a predetermined index element having a set orientation indicative of a reference physiological information, the predetermined index element being at least approximately determinable by an upstream determination of respective reference values, - a converter means for converting the plurality of characteristic index elements by projecting them to a disturbance-reduced index element derived from a given orientation and length of the plurality of characteristic index elements, the disturbance-reduced index element having a distinct orientation in relation to a presumed orientation of the disturbing signal component, wherein the disturbance-reduced index element is determined by optimizing an expression with consideration of the orientation of the predetermined index element, - wherein the sensor means is configured to detect electromagnetic radiation within at least one particular wavelength range selected from the group consisting of visible light, infrared light, and ultraviolet radiation, and wherein the sensor means is connectable to the interface, and wherein the sensor means is a video camera, wherein the converter means is further adapted for determining the disturbance-reduced index element by defining a dataset comprising a set of characteristic index element values derived by the extractor means, and by performing a transformation, preferably a substantially orthogonal linear transformation, of the dataset to a coordinate system, wherein a dominant component thereof is aligned with an axis of the coordinate system, wherein the dominant component coincides with the disturbance-reduced index element, and wherein the disturbance-reduced index element is determined by minimizing the energy of the projected characteristic index elements over a temporal interval. - an interface for receiving a data stream (76, 78, 80, 82) comprising a sequence of image frames derivable from electromagnetic radiation emitted or reflected by an object and detected by a sensor means, the sequence of image frames comprising a continuous or discrete characteristic signal including physiological information, the physiological information being representative of at least one at least partially periodic vital signal, - an extractor means for extracting the physiological information from the data stream (76, 78, 80, 82), the extractor means deriving a plurality of characteristic index elements from the data stream (76, 78, 80, 82), the plurality of characteristic index elements being indicative of the physiological information and a disturbing signal component, wherein the plurality of characteristic index elements is associated with a signal space representative of characteristics of the electromagnetic radiation, the signal space comprising a predetermined index element having a set orientation indicative of a reference physiological information, the predetermined index element being at least approximately determinable by an upstream determination of respective reference values, - a converter means for converting the plurality of characteristic index elements by projecting them to a disturbance-reduced index element derived from a given orientation and length of the plurality of characteristic index elements, the disturbance-reduced index element having a distinct orientation in relation to a presumed orientation of the disturbing signal component, wherein the disturbance-reduced index element is determined by optimizing an expression with consideration of the orientation of the predetermined index element, - wherein the sensor means is configured to detect electromagnetic radiation within at least one particular wavelength range selected from the group consisting of visible light, infrared light, and ultraviolet radiation, and wherein the sensor means is connectable to the interface, and wherein the sensor means is a video camera,