A Comparative Study of ECG-derived Respiration in Ambulatory Monitoring using the Single-lead ECG

Carolina Varon,Michele Orini,Pascal Borzée,Bertien Buyse,Raquel Bailón,Dries Testelmans,John Morales,Eduardo Gil,Leif Sörnmo,Jesús Lázaro,Spyridon Kontaxis,Pablo Laguna,Margot Deviaene

doi:10.1038/s41598-020-62624-5

Abstract

Cardiorespiratory monitoring is crucial for the diagnosis and management of multiple conditions such as stress and sleep disorders. Therefore, the development of ambulatory systems providing continuous, comfortable, and inexpensive means for monitoring represents an important research topic. Several techniques have been proposed in the literature to derive respiratory information from the ECG signal. Ten methods to compute single-lead ECG-derived respiration (EDR) were compared under multiple conditions, including different recording systems, baseline wander, normal and abnormal breathing patterns, changes in breathing rate, noise, and artifacts. Respiratory rates, wave morphology, and cardiorespiratory information were derived from the ECG and compared to those extracted from a reference respiratory signal. Three datasets were considered for analysis, involving a total 59 482 one-min, single-lead ECG segments recorded from 156 subjects. The results indicate that the methods based on QRS slopes outperform the other methods. This result is particularly interesting since simplicity is crucial for the development of ECG-based ambulatory systems.

Highlights

Despite the importance of monitoring respiration, its recording requires the use of invasive and intrusive sensors like thermistors, spirometers, and respiratory belts
In14, the ECG-derived respiration (EDR) was defined by the largest decrease of the 4th central moment of the ECG in segments between R- and S-waves; this method was evaluated for respiratory rate estimation only[28]
For the Drivers dataset, 21.7% of the segments are characterized by a bandwidth larger than 0.5 Hz, probably explained by poor-quality recordings or drivers constantly moving and speaking while driving[43]. This observation is supported by the result that the bandwidth was on average 0.26 Hz during the first 15 min when the drivers were relaxed with the car in idle, while the bandwidth increased to 0.45 Hz during driving

Summary

Introduction

Despite the importance of monitoring respiration, its recording requires the use of invasive and intrusive sensors like thermistors, spirometers, and respiratory belts. Even though these sensors are regularly used, for instance during polysomnographic recordings, their use in ambulatory systems is very limited since they interfere with natural breathing, but are often associated with high costs and low comfort. The derived signal is defined by certain morphological properties of the ECG influenced by respiration. This influence can be explained by the respiratory-induced chest movements that cause changes in the position of the electrodes relative to the cardiac vector[21]. The morphology of the ECG is modulated by respiration

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Results

Discussion

Conclusion