Computer-implemented method for synchronizing a photoplethysmography (PPG) signal with an electrocardiogram (ECG) signal

A computer-implemented method for synchronizing a PPG signal with an ECG signal comprises: - recording (101, 102) the ECG and PPG signals semi-synchronously; - cutting (103) the PPG signal into PPG signal pieces; - for a PPG signal piece (300): - determining (142-145) distances d between a vector of PPG peak times (301-315) and respective vectors of ECG peak times (351-365) for respective ECG signal pieces (350) obtained by applying different offsets o; - determining (104) a best matching ECG signal piece (350) with minimal distance do; and - registering (105) start time x of the PPG signal piece (300), start time yo of the best matching ECG signal piece (350), and the minimal distance do; - determining an offset and drift between the PPG signal and ECG signal as the offset and slope of a regression model (400) modelling the relation between the start time x and start time yo, inverse weighted by the minimal distance do; - applying the offset and drift to the PPG signal.