Temporal Artery Photoplethysmography as a Surrogate for Central Hemodynamics: From Pulse Transit Time Analysis to Deep Learning Estimation
摘要
Assessing aortic stiffness (AS) is key for early cardiovascular disease detection, as it reflects arterial wall mechanics and predicts adverse events. Carotidfemoral Pulse Wave Velocity (cfPWV) is the gold standard for non-invasive AS assessment, while Central Aortic Systolic Pressure (CASP) provides complementary information on cardiac afterload. This study explores the predictive value of Pulse Transit Time (PTT) measured at five peripheral sites (carotid, temporal, radial, digital, tibial) using a synthetic in-silico dataset. The temporal site showed the highest correlation with cfPWV and CASP and was selected for feature extraction from its photoplethysmography waveform. A fully-connected neural network was trained to estimate both cfPWV and CASP from these features. On a held-out test set, the model achieved high accuracy for cfPWV (R \(^2\) = 0.99, MAE = 0.10 m/s, RMSE = 0.13 m/s) and for CASP (R \(^3\) = 0.84, MAE = 2.89 mmHg, RMSE = 3.78 mmHg). These results highlight the diagnostic relevance of the temporal artery and support its use in non-invasive cardiovascular monitoring and potential cerebrovascular applications.