Method, apparatus and computer program product for analysing a pulse wave signal to determine an indication of blood pressure and/or blood pressure change

Abstract

According to an aspect, there is provided a computer-implemented method for analysing a pulse wave signal, PWS, obtained from a subject to determine an indication of the blood pressure or a change in blood pressure of the subject. The PWS comprises pulse wave measurements for a plurality of cardiac cycles of the subject during a first time period. The method comprises (i) analysing () the PWS to determine a first average cardiac cycle waveform for a first time point in the first time period and a second average cardiac cycle waveform for a second time point in the first time period; (ii) determining () a difference signal representing a change in morphology from the first average cardiac cycle waveform to the second average cardiac cycle waveform; (iii) determining () an absolute value of the change in morphology from the difference signal; (iv) determining () a direction of the change in morphology; and (v) determining () a relative blood pressure change by combining the absolute value and the direction of the change in morphology.