IoT technology with the 4.0 revolution in industrial technology promises to change drastically in every aspect of human life. The elderly health care industry is forecasted to grow fastly, providing a more economic and effective method for health monitoring through the utilization of IoT technology. Blood oxygen saturation (SpO2), one of the vital survival parameters, is potentially used in health monitoring on patients, elders and newborns, etc. This study focused on developing a SpO2 wearable measurement device, which allows the real-time monitoring and prediction of human health via the Internet. In addition to building a complete, low-cost and low-power assumption prototype, the study also focused on introducing different open-source solutions for data collection and display.