The ratio between VCO 2 and VO 2 is the respiratory exchange ratio (RER), which provides insight into the relative contribution of carbohydrates and lipids to overall energy expenditure. Indirect calorimetry (metabolic cart), which is currently the preferred method for determining metabolic fuel utilization, measures the carbon dioxide produced (VCO 2) and oxygen consumed (VO 2) when breathing. Regression analyses revealed an agreement between the two measurements ( F 1,63=18.54 P<.001).Ĭonclusions: This study shows the validity of Lumen for detecting changes in metabolic fuel utilization in a comparable manner with a laboratory standard metabolic cart, providing the ability for real-time metabolic information for users under any circumstances. Results: Both RER and Lumen % CO 2 significantly increased after glucose intake ( P<.001 for both) compared with fasting conditions, by 0.089 and 0.28, respectively. Reduced major axis regression and simple linear regression were performed to test for agreement between RER and Lumen % CO 2. Measurements were performed at rest in two conditions: fasting, and after consuming 150 grams of glucose, in order to determine changes in metabolic fuel usage. Methods: Metabolic fuel usage was assessed in healthy participants (n=33 mean age 23.1 years, SD 3.9 years) via respiratory exchange ratio (RER) values obtained from a metabolic cart as well as % CO 2 from the Lumen device. Objective: The aim of this study is to evaluate the validity of a novel handheld device (Lumen) for measuring metabolic fuel utilization in healthy young adults. A small handheld device capable of determining metabolic fuel usage via CO 2 from exhaled air has been developed. However, these systems are expensive, time-consuming, and only available in health care laboratory settings. JMIR Bioinformatics and Biotechnology 23 articlesīackground: Metabolic carts measure the carbon dioxide (CO 2) produced and oxygen consumed by an individual when breathing to assess metabolic fuel usage (carbohydrates versus fats).JMIR Biomedical Engineering 61 articles.JMIR Perioperative Medicine 69 articles.

Journal of Participatory Medicine 71 articles.

JMIR Rehabilitation and Assistive Technologies 177 articles.JMIR Pediatrics and Parenting 230 articles.Interactive Journal of Medical Research 259 articles.JMIR Public Health and Surveillance 964 articles.Journal of Medical Internet Research 6898 articles.

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