alexa Validation of a new mixing chamber system for breath-by-breath indirect calorimetry.
Diabetes & Endocrinology

Diabetes & Endocrinology

Journal of Obesity & Weight Loss Therapy

Author(s): Kim DY, Robergs RA

Abstract Share this page

Abstract Limited validation research exists for applications of breath-by-breath systems of expired gas analysis indirect calorimetry (EGAIC) during exercise. We developed improved hardware and software for breath-by-breath indirect calorimetry (NEW) and validated this system as well as a commercial system (COM) against 2 methods: (i) mechanical ventilation with known calibration gas, and (ii) human subjects testing for 5 min each at rest and cycle ergometer exercise at 100 and 175 W. Mechanical calibration consisted of medical grade and certified calibration gas ((4.95\% CO(2), 12.01\% O(2), balance N(2)), room air (20.95\% O(2), 0.03\% CO(2), balance N(2)), and 100\% nitrogen), and an air flow turbine calibrated with a 3-L calibration syringe. Ventilation was mimicked manually using complete 3-L calibration syringe manouvers at a rate of 10·min(-1) from a Douglas bag reservoir of calibration gas. The testing of human subjects was completed in a counterbalanced sequence based on 5 repeated tests of all conditions for a single subject. Rest periods of 5 and 10 min followed the 100 and 175 W conditions, respectively. COM and NEW had similar accuracy when tested with known ventilation and gas fractions. However, during human subjects testing COM significantly under-measured carbon dioxide gas fractions, over-measured oxygen gas fractions and minute ventilation, and resulted in errors to each of oxygen uptake, carbon dioxide output, and respiratory exchange ratio. These discrepant findings reveal that controlled ventilation and gas fractions are insufficient to validate breath-by-breath, and perhaps even time-averaged, systems of EGAIC. The errors of the COM system reveal the need for concern over the validity of commercial systems of EGAIC. This article was published in Appl Physiol Nutr Metab and referenced in Journal of Obesity & Weight Loss Therapy

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • 13th World Congress on Obesity
    Aug 24-25, 2017, Toronto, Canada
  • 13th Euro Obesity and Endocrinology Congress
    Sep 21-23, 2017, Madrid, Spain
  • 14th Global Obesity Meeting
    Oct 23-24, 2017 Dubai, UAE
  • 16th International Conference and Exhibition on Obesity & Weight Management
    November 13-15, 2017 Atlanta,Georgia, USA

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version