Monitoring System for Heart Rate, Blood Oxygen Level, and Body Temperature Using MAX30102 Sensor Based on Internet of Things

Human health can be monitored by measuring vital signs such as heart rate, oxygen saturation, and body temperature. A normal heart rate for adolescents ranges between 60–100 beats per minute. Abnormal conditions occur when the heart rate is below 60 bpm (bradycardia) or above 100 bpm (tachycardia). Likewise, normal blood oxygen saturation is between 95%–100%, and any value below this is considered abnormal. In addition to heart rate and oxygen levels, body temperature is also a critical indicator of one’s health status. While many health monitoring tools have been developed, most still require manual operation and cannot provide continuous, real-time monitoring. To address this, a health monitoring system was developed using NodeMCU ESP8266 as the microcontroller, integrated with the Blynk mobile application for real-time visualization. The system uses the MAX30102 and MLX90614 sensors to measure heart rate, oxygen level, and body temperature, and displays the data on a 0.96” OLED screen. A buzzer is used for alerts, and testing was performed by comparing results from the prototype with commercial-grade equipment. The system achieved an average accuracy of 97% during the tests.