Pilot Study on Electrocardiogram Derived Respiratory Rate Using a Wearable Armband

Abstract

A pilot study on deriving respiratory rate from electrocardiogram (ECG) signals recorded by a self-developed wearable armband is presented. The armband includes a pair of dry electrodes which record ECG and it is designed for long-term monitoring. Armband-ECG and plethysmography-respiration signals were simultaneously recorded from 5 subjects (3 male) while paced breathing at constant rates from 0.1 to 0.4 Hz (with an increment of 0.1 Hz). Respiratory rate was estimated from the armband-ECG by using a method based on the variations in QRS slopes and R-wave angle. The estimations were compared to those obtained from the respiration signal. Obtained median and interquartile ranges of the relative error were lower than 4% for every requested respiratory rate. This suggests that normal ranges of spontaneous respiratory rate could be estimated from the wearable armband, allowing us to consider it for long-term wearable cardio and/or respiratory monitoring.