Figure Correction: Resting and Postexercise Heart Rate Detection From Fingertip and Facial Photoplethysmography Using a Smartphone Camera: A Validation Study - Yan, Bryan P; Chan, Christy KY; Li, Christien KH; To, Olivia TL; Lai, William HS; Tse, Gary; Poh, Yukkee C; Poh, Ming-Zher (JMIR Publications, 2019)