Photoplethysmography Imaging (PPGI) is a non-invasive technology that utilizes camera-based sensors to measure blood volume changes in microvascular tissue. The resulting signal and the dynamics of the blood volume are significantly influenced by the cardiovascular system and its potential disturbance. This innovative approach enables remote monitoring of cardiovascular health or disease without the need for physical contact. Therefore, it enables fields of application where conventional methods are impractical or undesirable and offers additional potential for previously unknown or impossible areas of application. The integration of PPGI with wearable technologies and telemedicine platforms further amplifies its impact on patient care. It potentially allows for remote monitoring of patients with known cardiac issues, enabling timely interventions and reducing hospital visits. Due to its ease of use, it supports large-scale population studies aimed at identifying disease or understanding larger trends in cardiovascular health in different demographic groups. Recent advancements in image processing and machine learning have enhanced the accuracy and reliability of PPGI signals, facilitating their use in detecting cardiac arrhythmias and other heart-related anomalies. By analyzing subtle color variations in facial or skin images captured by standard cameras or smartphones, PPGI can provide real-time insights into heart rate variability and cardiac arrhythmia. This capability is crucial for early detection of conditions such as deterioration of cardiac activity or atrial fibrillation (AF), which often goes unnoticed until serious complications arise.
Challenges still remain regarding environmental factors affecting signal quality and the need for standardized protocols to ensure clinical applicability. Future research should focus on optimizing algorithms for reliable and robust performance under varying conditions and validating findings through clinical trials related to specific cardiac diseases and arrhythmias.