Chong KS, Gan KB, Mohd. Alauddin MA. Development of a Two-Channel Simultaneous Photoplethysmography Recording System. J. ICT Res. Appl. [Internet]. 2013Sep.13 [cited 2025Oct.13];6(2):171-82. Available from: https://journals.itb.ac.id/index.php/jictra/article/view/227