Roadmap of Photoplethysmography Technology in Advanced Cardiovascular Assessment

Abstract

This review explores the trajectory of photoplethysmography (PPG) technology from its inception in 1934 to its integration into smart devices in 2013. While PPG has proven effective in estimating left ventricular ejection time (LVET) and distinguishing between hypertensive and normotensive patients, challenges persist. The need for a robust mathematical model to explain physiological behaviors, address calibration protocols, and handle waveform variability is emphasized. Despite limitations, PPG is on the cusp of achieving clinical-grade confidence, particularly in estimating blood pressure and tracking vasomotor states. Integration into wearable devices is a prominent trend, with major companies exploring applications for improved health monitoring. Open-source databases and the availability of physiological data aim to enhance understanding, paving the way for universally accepted protocols. As PPG advances, it holds promise for personalized healthcare, revolutionizing treatment evaluations and preventive measures. However, potential disagreements over protocols may impede progress. Nevertheless, the technology's potential to remotely monitor cardiovascular markers could reduce physicians' workload for routine tasks. PPG stands as a beacon for the future of noninvasive cardiovascular assessment.