A method of measuring biological signals of a person including obtaining physiological signals； converting the physiological signals to an energy entropy signal, determining one or more statistical features based on the energy entropy signal, and selecting and combining two or more of the features. The features include two or more of: Shannon entropy of power spectral density (PSD) of energy entropy； minimum envelopes of three axis signals； minimum Shannon entropy of PSD of three axis entropies； standard deviation of interbeat intervals (IBIs)； differences of median filtered IBIs； determinism of recurrence plot of energy entropy； Kurtosis of energy entropy； minimum peak-to-peak amplitude three axis signals； peak-to-peak amplitude of energy entropy； laminarity of recurrence plot of energy entropy； Shannon entropy of horizontal structures in recurrence plot of energy entropy； standard deviation of time-averaged spectrogram； minimum standard deviation of peak positions in spectrogram； and minimum standard deviation of peak widths in spectrogram.
