A method (200) of deriving systolic blood pressure and/or diastolic blood pressure of a subject is disclosed. The method comprises: (i) receiving (202) data related to at least one cardiac cycle of a bio-signal from the subject； (ii) calculating (208) a rise time and a fall time of the at least one cardiac cycle based on the received data； (iii) calculating (208) a parameter derived from a function of the rise time and fail time； and (iv) determining (210) the systolic blood pressure and/or diastolic blood pressure of the subject based on the calculated parameter. A related apparatus is also disclosed.
