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ORIGINAL RESEARCH article

Front. Physiol.
Sec. Autonomic Neuroscience
Volume 15 - 2024 | doi: 10.3389/fphys.2024.1446868
This article is part of the Research Topic Cardio-Respiratory-Brain Integrative Physiology: Interactions, Mechanisms, and Methods for Assessment View all 3 articles

Using spectral continuity to extract breathing rate from heart rate and its applications in sleep physiology

Provisionally accepted
Gregoris A. Orphanides Gregoris A. Orphanides 1,2*Christodoulos Karittevlis Christodoulos Karittevlis 1Lujain Alsadder Lujain Alsadder 2Andreas A. Ioannides Andreas A. Ioannides 1
  • 1 Laboratory for Human Brain Dynamics, AAI Scientific Cultural Services Limited, Nicosia, Nicosia, Cyprus
  • 2 Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, England, United Kingdom

The final, formatted version of the article will be published soon.

    ECG-derived respiration (EDR) is a set of methods for extracting the breathing rate from the Electrocardiogram (ECG). Breathing rate and more specifically the breathing pattern is a vital sign that is less employed than Electroencephalogram (EEG) and heart rate in sleep and polysomnography studies, even though recent studies revealed a tight connection between breathing patterns during sleep and several related pathologies. This study utilised open-access data from the ISRUC sleep database to test a novel spectral-based EDR technique. In contrast to previous approaches, the novel method emphasizes spectral continuity and not only the power of the different spectral peaks. The method showcased improved performance in terms of accuracy when compared against the classic method ( Bailon et al., 2006). Thus, proposing spectral continuity EDR (scEDR) as a potential low-cost and non-invasive method for extracting the breathing rate using the heart rate during sleep with further studies required to validate its accuracy in awake subjects. This study further explores the breathing rate across sleep stages, providing evidence in support of a putative sleep stage "REM0" which was previously proposed based on analysis of the Heart Rate Variability (HRV) but not yet widely discussed. Most importantly, this study observes that the frequency distribution of the heart rate during REM0 is closer to REM than other NREM periods even though most of REM0 was previously classified as NREM sleep by the sleep experts. Finally, the autonomic balance across different sleep stages including REM0 was explored using HRV as a metric, revealing that sympathetic activity decreases as sleep progresses to NREM3 until it reaches a level similar to the awake state in REM through a transition from REM0.

    Keywords: scEDR, ECG Derived Respiration (EDR), REM0, Sleep staging, Sleep autonomic system, breathing

    Received: 10 Jun 2024; Accepted: 19 Jul 2024.

    Copyright: © 2024 Orphanides, Karittevlis, Alsadder and Ioannides. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Gregoris A. Orphanides, Laboratory for Human Brain Dynamics, AAI Scientific Cultural Services Limited, Nicosia, 1065, Nicosia, Cyprus

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.