Table 1.

Evaluation of DN detection of the IEM based algorithm in ABP and PPG cardiac cycles.

Cases	$N_R$	${\overline{SPD}}_R$ (SD) (s)	IEM based algorithm				2nd derivative method
			$N_D$	$D_R$ (%)	${\overline{SPD}}_M$ (SD) (s)	${\overline{\mathit{error}}}_{\mathit{DN}}$ (SD) (s)	$N_D$	$D_R$ (%)	${\overline{SPD}}_M$ (SD) (s)	${\overline{\mathit{error}}}_{\mathit{DN}}$ (SD) (s)
ABP (n’=87,345)	87,345	0.3448 (0.0336)	87,345	100 %	0.3448 (0.0333)	0.0047 (0.0029)	87,345	100 %	0.3675 (0.1005)	0.0693 (0.0770)
PPG (n’=86,766)	86,766	0.3564 (0.0286)	86,766	100 %	0.3565 (0.0283)	0.0046(0.0029)	86,766	100 %	0.4212 (0.1154)	0.0968 (0.0909)

ABP: Arterial blood pressure; PPG: Photoplethysmography; n’: Number of input cardiac cycles; ${\overline{SPD}}_R$: Mean of reference systolic phase duration; SD: standard deviation; ${\overline{SPD}}_M$: Mean of measured systolic phase duration by an algorithm; ${\overline{\mathrm{e}\mathrm{r}\mathrm{r}\mathrm{o}\mathrm{r}}}_{DN}$: mean error of DN detection; $N_R$: Reference dicrotic notches marked by an experienced researcher; $N_D$: Detected dicrotic notches by an algorithm; $D_R$: Rate of detectability.