System and method for extracting physiological information from remotely detected electromagnetic radiation

A method for extracting physiological information indicative of at least one health symptom from detected electromagnetic radiation with a photoplethysmographic monitoring system, the system comprising one or more sensors and one or more processors, the method comprising:

• receiving, with the one or more sensors, skin radiation information of a subject, the skin radiation information including wavelength-dependent image information, wherein the wavelength-dependent image information is composed of at least two color channels representative of respective wavelength portions, and wherein the wavelength-dependent image information comprises at least a pulsating signal component;
• detecting, with the one or more processors, relative channel signal strength information for the at least two color channels, wherein the relative channel signal strength information corresponding to the at least two color channels is represented by color vectors, and wherein the color vectors are moved along a path between minima and maxima corresponding to the pulsating signal component;
• comparing, with the one or more processors, the color vectors' path with a reference vector path, wherein the reference vector path is obtained by monitoring healthy subjects;
• and
• determining, with the one or more processors, blood composition-indicative information of the subject based on the comparison of the color vectors' path and the reference vector path