TABLE 3.

Overview of studies on peak detection of PPG.

Study	Subjects (age)	Recording time (minute)	Experimental condition (default is resting)	Device used	Sensor position	Peak type	Results
Canac et al., 2019	108 patients (30–64)	n.s.	Supine	Multi-Dop X (Compumedics DWL, Singen, Germany)	Head	Onset	Acc: 99.5%
Kavsaoğlu et al., 2016	20 healthy adults (18–41)	1	Sitting	SDPPG_V2.0 (APMKorea, Daejeon, Korea)	n.s.	Systolic	Acc: 100%
Ferro et al., 2015	10 healthy adults (19.3 ± 1.4)	5	Supine	In-house device	n.s.	Onset, systolic	Acc: 95% (onset) Acc: 100% (systolic)
Vadrevu and Manikandan, 2018	20 healthy adults (18–35)	10–15	Sitting	In-house sensor	Finger	Onset, systolic	Acc: 99.3% (onset) Acc: 99.3% (systolic)
Lu et al., 2008	10 healthy adults (26 ± 7.5)	20	Upright, supine	MP506 (Medtronic, MN, United States)	n.s.	Onset	Obtaining pulse rate variability highly correlated with heart rate variability
Shin et al., 2009	18 healthy adults (17–30)	5	Supine (respiratory control), Sitting (spontaneous breathing)	PPG 100C (Biopac, CA, United States)	Finger	Onset, systolic	Acc: 98.9% (onset) Acc: 98.2% (systolic)
Scholkmann et al., 2012	n.s.	3.5	n.s.	Functional near-infrared spectroscopy MCP-II (n.s.)	Prefrontal cortex	Systolic	Acc: 100%
Orjuela-Cañón et al., 2013	7 healthy adults (19.3 ± 1.5)	5	Supine	n.s.	n.s.	Onset, systolic	Acc: 100% (onset, systolic)

Acc, accuracy; n.s., not specified.