Method for determining a person's sleeping phase which is favourable for waking up

A pulse wave signal is registered and an occurrence of human limb movements detected during sleep using a pulse wave sensor and an accelerometer. The values of RR intervals and respiratory rate are measured at preset time intervals Δti based on pulse wave signal. Mean P1, minimal P2, and maximal P3 values of RR intervals, the standard deviation of RR intervals P4, average respiratory rate P5 and average number of limb movements P6 are determined based on the above measured values. Function value F(Δti) is determined thereafter as:F(Δti)=−K1P1−K2P2−K3P3+K4P4+K5P5+K6P6,where K1-K6 are weight coefficients characterizing the contribution of the corresponding parameter to function value F(Δti); whereat the onset and termination of sleep phase favorable to awakening is determined by increments of function F(Δti).