ABP	arterial blood pressure
ANN	artificial neural network
BP	blood pressure
CV	cross validation
CVDs	cardiovascular diseases
DBP	diastolic blood pressure
ECG	electrocardiogram
FFT	fast fourier transform
GDPR	general data protection regulation
HR	heart rate
LED	light-emmiting diode
LOSO	leave one subject out
LSTM	long short-term memory
MAE	mean absolute error
ME	mean error
PPG	photoplethysmogram
PPG’	1st derivative of photoplethysmogram
PPG”	2nd derivative of photoplethysmogram
PPT	pulse transit time
PSD	power spectral densitiy
PWV	pulse wawe velocity
RNN	recurrent neural networks
SBP	systolic blood pressure
WHO	World Health Organisation