ABSTRACT
We have developed four real-time methods for calculating a cardiointervalogram from a photoplethysmogram signal to calculate the total percentage of phase synchronization for estimating the state of the cardiovascular system. The methods were compared with the classical method of calculating a cardiointervalogram from an electrocardiogram signal using signals recorded from healthy volunteers and patients with COVID-19. © 2022 IEEE.
ABSTRACT
In this paper, we compare four methods of extracting the sequence of intervals between heartbeats from the photoplethysmogram signal to estimate the total percentage of phase synchronization of autonomic regulation circuits of blood circulation that are designed to operate in real time. In the analysis of the experimental ensemble of records of healthy subjects, the optimal parameters for the used approaches were selected. We compared cardiointervalograms obtained from photoplethysmogram signals with cardiointervalograms isolated from simultaneously recorded electrocardiogram signals during the analysis of phase synchronization between the phases of the extracted signals in the low-frequency range (0.04–0.15 Hz), which reflects the element activity of autonomic control of blood circulation. The operability of the approaches used in the analysis of the total percentage of phase synchronization of the autonomic regulation circuits of the cardiovascular system based on the photoplethysmogram signal for groups of healthy people and patients during COVID-19 was demonstrated.
ABSTRACT
The work aims to study the features of autonomic control of the cardiovascular system in two groups of patients with Covid-19: with and without arterial hypertension. A total of 15 pairs of 20-minute electrocardiogram and photoplethysmogram signals were registrated in each group. We used the methods of spectral analysis, as well as the previously proposed method for assessing the phase synchronization of 0.1-Hz rhythms of signals of autonomic control of heart rate and blood pressure. The data of patients with chronic arterial hypertension showed a lower level of synchronization than patients without it. This is probably due to the peculiarities of autonomic control of the cardiovascular system in patients with chronic arterial hypertension. © 2022 SPIE.
ABSTRACT
This work aims to analyze the coupling between autonomic control loops of blood circulation in patients with Covid-19. In this work, we assessed the degree of coupling between the mechanisms of autonomic control using noninvasive signals of the cardiovascular system - RR-intervals signals and photoplethysmogram signals. Statistical evaluation of the study results using the methods of phase synchronization analysis did not reveal significant differences between the sample of patients with Covid-19 and healthy subjects of the corresponding age group. © 2021 IEEE
ABSTRACT
This study aims to investigate the strength of synchronization between the autonomic control loops of the cardiovascular system (CVS) in patients with COronaVIrus Disease 2019 (COVID-19). Methods - We calculated the total percent of phase synchronization index (S index) between the loops of autonomic control of heart rate and vascular tone in two sample groups: healthy individuals and COVID-19 patients. Results - The group-average value of the S index in COVID-19 patients is lower comparing to healthy individuals, the Mann-Whitney U-test confirmed that the differences are statistically significant. Conclusion - Obtained results suggest that the decreased value of the S index reflects the presence of a viral disease, and the S index is a promising basis for non-invasive screening diagnostics of viral diseases, particularly of COVID-19.