BREATHIE: ESTIMATING BREATHING INHALE EXHALE RATIO USING MOTION SENSOR DATA FROM COMMODITY EARBUDS

Breathing Inhale/Exhale (IE) ratio is one of the critical breathing biomarkers for pulmonary patients and healthy individuals. It can indicate the severity of the lung obstruction for chronic lung patients and help detect psycho-social stress for healthy individuals. With the advancement of the wearable technologies, common consumer wearables such as smartwatches offer breathing rate. However, IE ratio measurement is not available in consumer electronic devices till today. In this paper, we present a novel algorithm, BreathIE, to estimate breathing rate and IE ration using low-power motion sensor embedded in consumer grade earbuds. Moreover, our algorithm is adaptive which is capable of dynamically adjusting to the varying breathing duration based on the breathing habit of the user at run time. We conducted a study with 30 participants where we use both earbuds and a reference chestband device simultaneously. Experimental evaluation against the annotated reference data shows that, our algorithm can estimate breathing rate with a mean absolute error (MAE) of 2.48 breaths per minute and breathing IE ratio with 0.26 MAE while outperforming the state-of-the-art algorithms.