Skip to main content
. 2023 Jun 7;9(23):eadh2694. doi: 10.1126/sciadv.adh2694

Fig. 5. Finger PPG testing under NIR illumination.

Fig. 5.

(A) Transmittance PPG collected from a volunteer’s finger under different NIR illumination wavelengths. (B) Comparison of PPG waveform and its derivatives, including the second derivative APG, highlighting the key areas of interest in a cardiac cycle.