A system for contact free energy expenditure assessment under free-living conditions: monitoring metabolism for weight loss using carbon dioxide emission. (22nd January 2021)

• Record Type: Journal Article
• Authors: Sprowls, Mark; Victor, Shaun; Serhan, Michael; Destaillats, Hugo; Wheatley-Guy, Courtney; Johnson, Bruce; Kulick, Doina; Forzani, Erica
• Is Part Of: Journal of breath research. Volume 15:Number 2(2021)
• Publication Date: 2021-01-22
• Subjects: ambient biometrics -- point of care -- minimally invasive biomedical diagnostic -- smart home biosensor -- internet of things (IoT); Volatile organic compounds -- Analysis -- Periodicals; Clinical chemistry -- Periodicals; Bad breath -- Periodicals; Bad breath -- Treatment -- Periodicals; Bad breath -- Diagnosis -- Periodicals; 616.0756
• DOI: 10.1088/1752-7163/abd52f
• Languages: English
• ISSNs: 1752-7155

Abstract

Abstract: Weight disorders are strikingly prevalent globally and can contribute to a wide array of potentially fatal diseases spanning from type II diabetes to coronary heart disease. These disorders have a common cause: poor calorie balance. Since energy expenditure (EE) (kcal d −1 ) constitutes one half of the calorie balance equation (the other half being food intake), its measurement could be of great value to those suffering from weight disorders. A technique for contact free assessment of EE is presented, which only relies on CO2 concentration monitoring within a sealed office space, and assessment of carbon dioxide production rate (VCO2 ). Twenty healthy subjects were tested in a cross-sectional study to evaluate the performance of the aforementioned technique in measuring both resting EE (REE) and exercise EE using the proposed system (the 'SmartPad') and a U.S. Food and Drug Administration (FDA) cleared gold standard reference instrument for EE measurement. For VCO2 and EE measurements, the method showed a correlation slope of 1.00 and 1.03 with regression coefficients of 0.99 and 0.99, respectively, and Bland–Altman plots with a mean bias = −0.232% with respect to the reference instrument. Furthermore, two subjects were also tested as part of a proof-of-concept longitudinal study where EE patterns were simultaneously tracked with body weight, sleep, stress, and step counts using a smartwatch over the course of a month, to determine correlation between the aforementioned parameters and EE. Analysis revealed moderately high correlation coefficients (Pearson's r ) for stress ( r average = 0.609) and body weight ( r average = 0.597) for the two subjects. The new SmartPad method was demonstrated to be a promising technique for EE measurement under free-living conditions.