Development of a Reflectance Photoplethysmogram Based Heart Rate Monitoring Device

This paper presents a method for users to monitor their heart rate conveniently. It becomes necessary for individuals to know their heart rate because of the fact that cardiovascular disease is the leading cause of death in the world, especially in developing countries. Heart rate measurement is an indication of how healthy the heart is. This heart rate monitor (HRM) uses the technique of reflectance photoplethysmography (PPG) to detect the pulse from the fingertip, filter and amplify the pulse using two-stage OP-Amp, count and decodes the pulse with the aid of a microcontroller and display the output in beats per minutes (BPM) on an LCD. The device is easy to use, cheap and portable compared to the expensive ones available that also requires medical expertise. It can be used by athletes and anybody to monitor the state of their heart rate with negligible error.