Flow Mediated Dilation (FMD) is a non-invasive method for endothelial function assessment providing an index extracted from ultrasonic B-mode images. Although utilized in the research community, the difficulty of its application and high cost of ultrasonic device prevent it from being widely used in clinical settings. In this study we show that substituting the ultrasonic device with more easily handled and low cost photoplethysmography and electrocardiography is possible. We introduce new indices based on the photoplethysmogram (PPG) and electrocardiogram (ECG) and show that they are correlated with the ultrasound-based FMD index. To this end, conventional ultrasound FMD test was carried...