A device and a method for extracting information from detected characteristic signals are provided. A data stream (26) derivable from electromagnetic radiation (20) emitted or reflected by an object (10) is received. The data stream (26) includes a continuous or discrete characteristic signal (68) including physiological information (30) indicative of desired object motion to be detected and utilized so as to extract at least one at least partially periodic vital signal of interest. A plurality of characteristic index elements (60) can be derived from the data stream (26) through a dimensional reduction (66). The plurality of characteristic index elements (60) includes a directional motion component (70) associated with a disturbance-reduced index element (40) having a determined orientation substantially aligned with a reference motion direction (41) indicative of the desired object motion. Consequently, dimensional reduced data can be utilized for detecting the vital signal of interest.