Segmented-Beat Modulation Method-Based Procedure for Extraction of Electrocardiogram-Derived Respiration from Data Acquired by Wearable Sensors During High-Altitude Activity

High-altitude sports are affected by hypoxic stress-related alterations and, consequently, may trigger severe events such as sport-related sudden death; thus, into-the-jield monitoring of respiration is essential. A Segmented-Beat Modulation Method (SBMM)-based procedure was previously proposed to extract electrocardiogram
$(ECG)$
- derived respiration
$(EDR)$
. The aim of this study is to validate SBMM-based procedure for
$EDR$
extraction in data acquired by wearable sensors during high-altitude physical activities. Respiration signal
$(RES)$
and
$ECG$
were recorded using BioHarness 3.0 by Zephyr from 3 expeditioners, while performing a trek up to 4,
$556m$
of altitude.
$EDR{\it was}$
extracted from
$ECG$
by SBMM-based procedure.
$RES$
and
$EDR$
were segmented into 60-second windows and characterized in terms of breathing rate (
$BR_{RES}$
and
$BR_{EDR}$
, respectively).
$BR_{RES}$
and
$BR_{EDR}$
were compared by absolute difference
$(\vert \delta\vert)$
, concordance correlation coefficient
$(CCC)$
and linear regression analysis. Results confirmed
$EDR$
goodness, proved by low values of
$\vert \delta\vert (2[1;4]cpm)$
, satisfactory
$CCC(0.62$
; P-value
$< 0.05$
) and good fit of regression line
$(BR_{RES}=0.91\cdot BR_{EDR}+4.47cpm)$
. In conclusion, SBMM-based procedure is a good method to extract
$EDR$
from data acquired by wearable sensors during high-altitude physical activities.