Applying the 3-element windkessel model to photoplethysmographic signals. Gender differences and age correlation

Resumen

Automatically averaged photoplethysmographic (PPG) signals were fit to a 3-element windkessel model using a Gauss-Newton optimization algorithm. Data corresponded to 78 healthy subjects (ages from 8 to 87 years). Unlike other reports, two phase velocities are also estimated from the model. Gender differences were found, particularly respect to individual parameters correlation with age. When a nonlinear model was fit to the two first principal components, a high correlation with age was found for both females (r=0.69) and male subjects (r=0.77). Our results further support the idea that the PPG signal is a valuable source of information about the cardiovascular system, comparable to the much more expensive continuous pressure signal.

Key words: photoplethysmographic signal, windkessel model, cardiovascular age, mathematical model.