Estimation of Tidal Volume during Exercise Stress Test from Wearable-Device Measures of Heart Rate and Breathing Rate

Abstract

Tidal volume (TV), defined as the amount of air that moves in or out of the lungs with each respiratory cycle, is important in evaluating the respiratory function. Although TV can be reliably measured in laboratory settings, this information is hardly obtainable under everyday living conditions. Under such conditions, wearable devices could provide valuable support to monitor vital signs, such as heart rate (HR) and breathing rate (BR). The aim of this study was to develop a model to estimate TV from wearable-device measures of HR and BR during exercise. HR and BR were acquired through the Zephyr Bioharness 3.0 wearable device in nine subjects performing incremental cycling tests. For each subject, TV during exercise was obtained with a metabolic cart (Cosmed). A stepwise regression algorithm was used to create the model using as possible predictors HR, BR, age, and body mass index; the model was then validated using a leave-one-subject-out cross-validation procedure. The performance of the model was evaluated using the explained variance (R2), obtaining values ranging from 0.65 to 0.72. The proposed model is a valid method for TV estimation with wearable devices and can be considered not subject-specific and not instrumentation-specific.

Wearable and Portable Devices for Acquisition of Cardiac Signals while Practicing Sport: A Scoping Review

“…Market research forecasts a grow in the sport and fitness industry with heavy future investment in terms of industrial research, with the aim to improve the sensors in terms of flexibility, motion, and smart textiles [ 10 , 14 , 16 ]. New innovations further include the reliable estimation of blood pressure, oxygen saturation, body temperature, and respiratory rate [ 14 , 17 , 18 , 19 ]. Of note, optical sensory components will lead revenue for wearable devices [ 10 ].…”

Cardiorespiratory Assessments in Panic Disorder Facilitated by Wearable Devices: A Systematic Review and Brief Comparison of the Wearable Zephyr BioPatch with the Quark-b2 Stationary Testing System

“…Recently, we used a stepwise regression algorithm to indirectly estimate TV during exercise from wearable-device-based measurements of HR and BR [ 67 ]. Due to the preliminary nature of our analyses, we focused only on HR and BR, which are directly measured by the Zephyr BioPatch, to explore potential basal misestimations and provide “starting-point” comparisons that are easily usable without the application of inferential methods.…”

“…Due to the preliminary nature of our analyses, we focused only on HR and BR, which are directly measured by the Zephyr BioPatch, to explore potential basal misestimations and provide “starting-point” comparisons that are easily usable without the application of inferential methods. However, the novel possibility of estimating TV from HR and BR [ 67 ], or TV variability from accelerometer-based signals [ 23 , 54 , 55 , 56 , 57 ] recorded by the Zephyr BioPatch, paves the way for further analyses to extend our comparisons to TV.…”

Identification of Respiration Types Through Respiratory Signal Derived From Clinical and Wearable Electrocardiograms

“…EDR methods based on amplitude modulation depend on electrode position and are able to better identify differences between extracted EDR. Consequently, the Segmented-Beat Modulation Method-based algorithm, possibly like other algorithms relying on ECG amplitude modulation [23] , [24] , provides a better estimation of breathing amplitude (Table II ), which plays an important role in the identification of the breathing type [4] , [5] , [6] . This also explains why breath holding and deep breathing, which are the respiration types with the lowest and highest breathing amplitude, respectively, are better identified than normal breathing, which is the respiration type with the intermediate breathing amplitude.…”

“…BA is the volume of air that moves in and out of the lungs with each respiratory cycle [1] and, in healthy adults, it ranges between 300 mL and 500 mL [1] , [3] . Despite BR being considered as a primary index for breathing evaluation, information provided by BA is also essential [4] , [5] , [6] . Indeed, BR and BA reflect two different physiological mechanisms: BR is mainly regulated by the autonomic nervous system, while BA is specifically regulated by metabolic inputs [4] , [6] ; moreover, they present an unbalanced association, being BA continuously adjusted according to BR, but not vice versa [5] , [7] .…”