Day-to-day repeatability of the results of the finger-toe-plot analysis

Non-invasive arterial pulse wave (PW) measurement provides valuable information on the vascular health. The aim of the study is to characterize the between-visit or day-to-day repeatability of combined finger and toe photoplethysmographic (PPG) signal analysis method called finger-toe plot (FT-plot) and compare it with the repeatability of other methods proposed for vascular characterization. Ten 22–36-year-old subjects were examined on 3 different days in order to find out the day-to-day repeatability of the results. The repeatability of the extracted parameters was analyzed by means of intra-class correlation coefficients (ICC) and free-marginal multirater \(\kappa \) agreement. ICCs varied widely from below 0.2 to almost 0.9, but \(\kappa \) coefficients higher than 0.7 were achieved for most of the results. Based on the presented results, the FT-plot analysis has at least sufficient day-to-day repeatability. However, further studies with real patients and different stages of cardiovascular diseases are required for confirming the findings.