Development of a Handheld Side-Stream Breath Analyser for Point of Care Metabolic Rate Measurement

A novel handheld side-stream breath analyser has been developed. The low-cost device offers breath-by-breath measurements of O2, CO2, temperature, relative humidity and gas flow rate. Metabolic rate can be calculated from the inspired and expired gas concentrations; a knowledge of this over a 24 h period can guide calorific intake. The analyser provides easy-to-read results on either a laptop or smart phone. Results for the O2 and CO2 sensors demonstrate the device’s potential for metabolic rate breath analysis. The O2 sensor is not able to follow changes in O2 concentration during the breathing cycle; however, the newly developed affordable and low-power consumption CO2 sensor performs comparably to a bulky, high power consumption commercial device.