Fig. 2
From: Empirical retinal venous pulse wave velocity using modified photoplethysmography
A Harmonic regression wave amplitude (HRW\(_{\text {a}}\)) for the whole image field. B HRW\(_{\text {a}}\) along the imaged inferior venous segment up to 0.5Â mm from the center of the optic disc. C Time to harmonic regression wave minimum for the whole image field in fractions of the cardiac cycle. D Time to harmonic regression wave minimum along the imaged inferior venous segment up to 0.5Â mm from the center of the optic disc