Development and Multicenter Validation of an AI-Based Remote Photoplethysmography (rPPG) Facial Scan for Multimodal Health Assessment

Remote photoplethysmography (rPPG) is an emerging non-contact optical technology that enables extraction of physiological signals from facial video using standard cameras. This approach has gained increasing attention in telemedicine due to its scalability, cost-effectiveness, and ability to perform remote health screening. Recent advancements in artificial intelligence (AI) have further expanded the potential of rPPG beyond basic vital sign monitoring to include estimation of cardiometabolic biomarkers and health risk indices. However, comprehensive validation of rPPG-based systems against standardized clinical measurements, laboratory biomarkers, and psychological parameters remains limited, particularly in low- and middle-income settings such as Indonesia. Given the high burden of cardiometabolic diseases in urban populations like Jakarta, evaluating the accuracy and feasibility of AI-based facial scanning technologies is essential to support early detection and digital health integration.

Specific Objectives

• To assess the agreement between rPPG derived vital signs (heart rate, respiratory rate, blood pressure, SpO₂) and corresponding measurements obtained from standardized physical examination by trained personnel and validated medical devices
• To determine the degree of concordance between rPPG based estimates and laboratory values of hemoglobin, blood glucose, HbA1c, LDL, HDL, triglycerides, and total cholesterol.
• To analyze the association between rPPG derived physiological parameters and levels of depression, anxiety, and stress as measured by the DASS 21 questionnaire.
• To calculate mean arterial pressure (MAP), ASCVD risk scores, and heart age from rPPG outputs and to compare these indices with those derived from standard clinical and laboratory data.
• To develop and preliminarily evaluate exploratory algorithms using rPPG video data to estimate kidney function, liver function, muscle mass, visceral fat, body weight, body height, body mass index, and subcutaneous fat as potential screening parameters.

Methods This study will employ a multicenter observational design conducted across selected subdistricts in Jakarta and expanded to the Jabodetabek region. Adult participants will undergo comprehensive assessment including psychological questionnaires (DASS, PHQ, GAD), anthropometric measurements, body composition analysis, spirometry, muscle strength testing, and venous blood sampling. Blood samples will be analyzed using POCT (≤30 minutes) and ISO-standardized clinical laboratory methods. In parallel, participants will undergo a non-contact facial scan, generating rPPG-based outputs including vital signs, hemodynamic indices, and AI-estimated biomarkers. Statistical analysis will include Bland-Altman agreement analysis, Cohen's kappa for categorical variables, correlation analysis, and machine learning performance metrics (MAE, MSE, RMSE, R²).

Expected Results It is expected that rPPG-based measurements will demonstrate good agreement with standard clinical measurements for core vital signs (heart rate, respiratory rate, SpO₂), with moderate agreement for blood pressure and selected biomarkers. AI-based models are anticipated to show acceptable predictive performance for certain metabolic parameters and exploratory variables, supporting the feasibility of rPPG as a screening tool. The study is also expected to identify key confounding factors, such as skin tone and demographic variability, influencing signal accuracy.

Inclusion criteria

• Adults aged ≥18 years.
• Able and willing to provide written informed consent.
• Able to comply with study procedures, including face scan, physical examination, blood sampling, and questionnaire completion.
• Clinically stable at the time of assessment.

Exclusion criteria

• Facial conditions affecting the region of interest (ROI), such as injury, deformity, or impaired circulation, that may interfere with rPPG signal acquisition.
• Presence of facial tattoos or coverings that obstruct optical signal detection.
• Inability to remain still or comply with measurement procedures during data acquisition.
• Severe medical conditions that preclude safe participation, as judged by the investigator.
• Incomplete data or withdrawal of consent during the study.

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