Design of an Infrared based Blood Oxygen Saturation and Heart Rate Monitoring Device

Abstract

<p>The purpose of the project was to design a remote non-invasive health monitoring system. Health information would be collected and transferred to a processing centre wirelessly, where it can be monitored and forwarded to necessary personnel. Heart Rate and Blood Oxygen Saturation are a couple of such biometrics that are monitored in this project. Change in intensity of light transmitted through tissue due to arterial blood pulse can be measured as a voltage signal. This technique is called Photoplethysmography (PPG), and can be used to calculate the heart rate. Furthermore, oxygenated blood has different light absorption characteristics than deoxygenated blood under Red and Infrared wavelengths. Comparing the two absorptions can produce an estimate of the oxygen saturation of the blood. Time Multiplexing was sued to collect the two PPGs (Red and Infrared) simultaneously. The hardware design and the software processing required to measure these biometrics will be presented.</p>