Table 1 Definition and illustration of parameters

AA

the area under curve of the anacrotic phase

the area of the OPT curve

AC

the area under curve of the catacrotic phase

the area of the OPT’ curve

AT

the area under curve of a total period

the area of the TPT’ curve

MHA

the mean height of the anacrotic phase in terms of area

\(MHA = \frac{1}{{t1 - {\text{t}}0}}\int_{t0}^{t1} {p\left( t \right)dt} \)

MHC

the mean height of the catacrotic phase in terms of area

\(MHC = \frac{1}{{t2 - {\text{t}}1}}\int_{t1}^{t2} {p\left( t \right)dt} \)

MH

the mean height of a wave in terms of area

\(MH = \frac{1}{{t2 - {\text{t}}0}}\int_{t0}^{t2} {p\left( t \right)dt} \)

PBI

pulse beat interval

the time interval between adjacent troughs, T-T’

PPGA

the photoplethysmography amplitude

The height of line OP