A Smart System for the Contactless Measurement of Energy Expenditure

Area of Science:

• Metabolic Physiology
• Biomedical Engineering
• Environmental Monitoring

Background:

• Energy Expenditure (EE) is crucial for obesity treatment and typically measured using methods requiring facial accessories.
• Existing technologies for measuring EE, such as those relying on oxygen consumption (VO2) or carbon dioxide production (VCO2), are often cumbersome.

Purpose of the Study:

• To evaluate a novel Smart Pad system for measuring EE via ambient CO2 transients, removing the need for wearable sensors.
• To assess the accuracy and influence of measurement duration on the Smart Pad's ability to measure resting EE (REE) and exercise VCO2.

Main Methods:

• The Smart Pad system measured VCO2 by analyzing ambient CO2 concentration changes within a room.
• Measurements of REE and exercise VCO2 were taken using both the Smart Pad and a reference instrument.
• The system was validated across a range of body mass indexes (BMI) and EE levels.

Main Results:

• The Smart Pad achieved 90% accuracy for REE measurements (14-19 min) and exercise VCO2 (4.8-7.0 min) with a known air exchange rate.
• Validation across BMIs from 18.8 to 31.4 kg/m2 confirmed system accuracy for REE ranges of ~1200 to ~3000 kcal/day.
• A new model for REE measurement, independent of lambda calibration, showed nearly 100% agreement with reference instruments (R=0.937).

Conclusions:

• The Smart Pad offers a non-invasive, accurate method for measuring energy expenditure without facial accessories.
• The developed model enhances REE measurement accuracy, simplifying clinical applications for obesity management.
• This technology has the potential to improve accessibility and adherence in metabolic monitoring and weight management programs.