An assessment of a similarity between the right and left hand Photoplethysmography signals, using time and frequency features of heart-rate-variability signal

Photoplethysmography is a noninvasive technique to measure the blood volume changes in blood vessels, based on the intensity of absorbed or backscattered light by infrared sensors, which is used in a wide range of medical applications. The study of the feasibility of using the PPG signals of both hands simultaneously is one of the aims of this research. In this research, PPG signals of 23 volunteers aged 25 to 28 years have been acquired in the relaxation state. For each volunteer, recordings were repeated 12 times. So, the collected dataset included totally 276 sets of signals which were taken into investigation. First, in order to evaluate the similarities between the obtained signals, linear associations between the right and left hand PPG signals have been measured by Pearson correlation coefficient and then, the differences between time and frequency domain features of HRV signals which derived from right and left hand fingertip Photoplethysmography have been analyzed using the paired t-test. The obtained results indicate that there is no salient different between these two signals (P < 0.05). In addition, analysis of the existing differences between the extracted parameters of these two signals by employing the Bland-Altman test shows that the high degree of agreement exists between the extracted features of the right and left hand PPG signals.