An IoT-Enabled Photoplethysmography $\text{SpO}_{2}$ Monitoring System: Design and Performance Evaluation

Oxygen saturation <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\text{SpO}_{2})$</tex> monitoring is essential for assessing respiratory and cardiovascular health, particularly in patients with heart or pulmonary conditions. Early detection of hypoxia through continuous <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SpO}_{2}$</tex> monitoring enables timely medical intervention, improving patient outcomes. However, Malaysian government hospitals and clinics face challenges such as limited access to monitoring devices, manual data entry, resource constraints, and the lack of real-time monitoring capabilities. To address these issues, this study proposes the development of an IoT -enabled <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SpO}_{2}$</tex> monitoring system using ESP32 and Blynk, enhancing patient care and facilitating seamless data sharing. The system's accuracy is evaluated using the Design of Experiment (DoE) and Analysis of Variance (ANOV A) to identify key factors influencing <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SpO}_{2}$</tex> measurement precision. Statistical analysis reveals that the index finger provides more accurate readings compared to the thumb. Additionally, environmental conditions significantly affect measurement accuracy, with low illumination yielding the highest precision. These findings contribute to the standardization of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SpO}_{2}$</tex> measurement techniques, ensuring consistency and reliability across diverse healthcare settings.