Low-Cost Multi-Parameter Vital Sign Monitoring Using Arduino and IoT Alerts

Continuous monitoring of vital signs is essential for early detection of physiological abnormalities, yet conventional hospital-based systems are often costly and require intensive manual intervention. This study presents the design, implementation, and evaluation of a low-cost, Arduino-based multi-parameter health monitoring system capable of measuring heart rate, blood oxygen saturation (SpO₂), body temperature, and electrocardiogram (ECG) signals in real time. The proposed system integrates multiple biomedical sensors with an Arduino microcontroller, providing local visualization via an LCD interface and automated alerting through buzzer and LED indicators when predefined physiological thresholds are exceeded. To enable remote monitoring, the system transmits sensor data using a NodeMCU module to a cloud-based IoT platform (Ubidots) for visualization and logging. Experimental validation was conducted on 15 participants, with three repeated measurements collected per participant for heart rate, SpO₂, and body temperature. The results demonstrate stable real-time performance and reliable detection of abnormal conditions. A practical limitation identified is the reduced granularity of cloud-based graphs due to transmission rate constraints, despite accurate local monitoring. Overall, the findings confirm that low-cost, modular microcontroller-based systems can provide effective multi-vital monitoring and alerting, particularly in resource-constrained healthcare environments.