Short-term stability of combined finger and toe photoplethysmogram analysis

Abstract

<p>Arterial pulse waves (PWs) provide information on the vascular health and could be utilized in the early detection of atherosclerosis. The aim of the study is to characterize the short-term repeatability of combined finger and toe photoplethysmographic (PPG) signal analysis method which we call finger-toe plot (FT-plot) and compare it with other methods proposed for vascular characterization. PPG signals were recorded from 24 atherosclerotic and 47 control subjects from finger and toe. The repeatability of the method was analyzed by means of intra-class correlation coefficients (ICC) and free-marginal multirater κ agreement. The metrics were computed for individual PWs as well as for averages based on 10–100 PWs. The ICCs increased with number of PWs utilized — ICCs and κ agreements higher than ≥ 0.90 were widely achieved based on the averages of ≥ 20 PWs, depending on the parameter or study group. Based on the present results, the FT-plot based detection of atherosclerotic changes has at least equal repeatability compared with a current clinical standard, ankle-to-brachial pressure index. However, further studies should validate the findings before the method is ready for the screening of atherosclerotic changes.</p>