1. Device for extracting information from detected characteristic signals, comprising: an interface ( 28 ) for receiving a data stream ( 26 ) derivable from electromagnetic radiation ( 14 ) reflected by an object ( 12 ), the data stream ( 14 ) comprising a continuous or discrete time-based characteristic signal ( p ; 98 ), the characteristic signal ( p ; 98 ) comprising at least two main components ( 92 a , 92 b , 92 c ) associated with a signal space ( 88 ), the signal space ( 88 ) comprising complementary channels ( 90 a , 90 b , 90 c ) for representing the characteristic signal ( p ; 98 ), the main components ( 92 a , 92 b , 92 c ) of the characteristic signal ( p ; 98 ) being related to respective complementary channels ( 90 a , 90 b , 90 c ) of the signal space ( 88 ), a converter means ( 36 ) for mapping the characteristic signal ( p ; 98) to a defined component representation ( b , h, s , c ; T , c ) under consideration of a substantially linear algebraic signal composition model so as to specify a linear algebraic equation, the characteristic signal ( p ; 98 ) being at least substantially composed of a physiologic reflection component ( 100 ) and a disturbing reflection component ( 102 ), wherein the physiologic reflection component ( 100 ) comprises a basic reflection portion ( 104 ) attributable to basic physiologic properties of the object ( 12 ) to be observed and an indicative reflection portion ( 106 ) attributable to at least one at least partially periodic vital signal ( 20 ), wherein the basic reflection portion ( 104 ) comprises a basic reflection index element ( b ) and a basic reflection coefficient (c 0 ), wherein the indicative reflection portion ( 106 ) comprises an indicative reflection index element (h) and a time-dependent indicative reflection coefficient (c 1 ), the indicative reflection coefficient (c 1 ) being highly indicative of the at least one at least partially periodic vital signal ( 20 ) of interest, wherein the disturbing reflection component ( 102 ) comprises a disturbing reflection index element ( s ) and a disturbing reflection coefficient (c 2 ), a processing means ( 40 ) for at least partially solving the linear algebraic equation under consideration of an at least approximate estimation of the orientation of the basic reflection index element ( b ), the indicative reflection index element (h) and the disturbing reflection index element ( s ) so as to derive an expression highly indicative of the at least one at least partially periodic vital signal ( 20 ), the highly indicative expression at least comprising the indicative reflection coefficient (c 1 ).