The present invention relates to a system for monitoring a subject, the system comprising: a non-contact sensor configured to detect a portion of a first output signal reflected from the subject, the detected reflected signal being processed to derive a raw motion signal； and a processor configured to: process the raw motion signal so as to obtain at least two of a respiratory signal, a cardiac signal and a motion signal；derive a plurality of statistical features using the at least two signals of the respiratory signal, the cardiac signal and the motion signal, the plurality of derived statistical features including at least two of statistical respiratory features derived from the respiratory signal, statistical cardiac features derived from cardiac signal, and statistical motion features derived from the motions signal, and the processor being further configured to selectively combine selected statistical features to estimate a parameter that provides a measure of one or more of a sleep disorder, sleep state or sleep disturbance； and a display configured to provide physiological information based on one or more of the plurality of statistical features or the estimated parameter.
