Breath holds the key to monitoring fat burning, and now a research group from Tohoku University in Japan has created a compact device that uses an ultraviolet lamp to gauge exhaled acetone gas, which is produced in the blood through the metabolic reaction of fat. The details of their study have been published in the journal Sensors.
In a statement, research leader Professor Yuji Matsuura from Tohoku University's Graduate School of Biomedical Engineering said: "Precise measurements of acetone gas concentration allows us to determine the body's ability to metabolise fat and develop exercise methods for efficient fat burning."
Matsuura and his team focused on ultraviolet light because it is extremely short wavelength is strongly absorbed by acetone gas. According to the University, they succeeded in measuring the acetone concentration with high accuracy: 0.03 ppm, while the acetone concentration is about 1ppm in exhaled air.
To do this, they trapped exhaled air in a hollow optical fibre - a long-path and an extremely small-volume gas cell - that had been exposed to vacuum ultraviolet light produced from an ultraviolet lamp. The group measured the degree to which the light is weakened as a result of the absorption of acetone gases to ascertain the acetone gas concentration.
When putting the device to use the group discovered that fat burning rates gradually increased after exercise. In contrast, the rate remained constant during exercise, indicating that a substantial part of fat metabolisation occurs after exercise.
Until now, a large mass spectrometer was required to monitor fat metabolisation. The new device, however, comprises a lamp, the hollow optical fibre, and a small spectrometer making it compact and low cost.
"The present research may also lead to non-invasive diagnosis methods for diabetes, since diabetic patients have high concentrations of acetone gas in their breath," said Matsuura.