Estimating Oxygen Uptake During Nonsteady-State Activities and Transitions Using Wearable Sensors

• Published in: IEEE journal of biomedical and health informatics Vol. 20; no. 2; pp. 469 - 475
• Main Authors: Altini, Marco, Penders, Julien, Amft, Oliver
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.03.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accelerometers; Accelerometry - methods; Adult; Calorimetry; Data models; Energy Expenditure; Energy Metabolism - physiology; Estimating; Estimation; Female; Heart Rate; Households; Humans; Legged locomotion; Logistics; Male; Mathematical models; Monitoring, Ambulatory - methods; Non-Steady-State; Oxygen - metabolism; Oxygen consumption; Oxygen Consumption - physiology; Predictive models; Sensors; Signal Processing, Computer-Assisted; Steady-state; Uptakes; V O2; Walking; Walking - physiology; Accelerometers; VO2; heart rate; nonsteady-state; energy expenditure
• DOI: 10.1109/JBHI.2015.2390493
• ISSN: 2168-2194

In this paper, we present a method to estimate oxygen uptake (VO 2 ) during daily life activities and transitions between them. First, we automatically locate transitions between activities and periods of nonsteady-state VO 2 . Subsequently, we propose and compare activity-specific linear functions to model steady-state activities and transition-specific nonlinear functions to model nonsteady-state activities and transitions. We evaluate our approach in study data from 22 participants that wore a combined accelerometer and heart rate sensor while performing a wide range of activities (clustered into lying, sedentary, dynamic/household, walking, biking and running), including many transitions between intensities, thus resulting in nonsteady-state VO 2 . Indirect calorimetry was used in parallel to obtain VO 2 reference. VO 2 estimation error during transitions between sedentary, household and walking activities could be reduced by 16% on average using the proposed approach, compared to state of the art methods.