Design and Fabrication of Heart Rate and Oxygen Saturation Measurement Device using LED-LED Configuration and to Study Correlation of PPG Signal Amplitude with Breathing Rate. PJOSR [Internet]. 2023 Jul. 6 [cited 2026 Feb. 16];3(1):113-8. Available from: https://paas-pk.org/index.php/pjosr/article/view/1883