Breath Sensor Measures Exhaled Gas Components

A portable breath sensor can measure the concentration of specified gas components correlated with lifestyle diseases such as high blood pressure, diabetes, and cancer.

The sensor, developed at Fujitsu Laboratories (Kawasaki, Japan), identifies ammonia, which is associated with liver metabolism; there is also a link between ammonia and Helicobacter pylori infection, a risk factor for stomach cancer. The sensor’s ammonia-adsorbing copper(I)-bromide films and a measurement algorithm are used to quantify ammonia in terms of electrical resistance on the film that correlate to the gas concentration. The test can be performed in just 10 seconds.

The sensor can measure a fraction of ammonia as small as 10 parts per billion (ppb) in a person's breath, a sensitivity differential that is roughly 2,500 times higher than that of acetone. When the researchers added a thin layer of tertiary amine molecules on the surface of the copper(I)-bromide film, they created an altered sensor that is capable of detecting nonanal (C9H18O)--an aldehyde compound that is a candidate biomarker for lung cancer--at concentrations of 200 ppb.

Fujitsu Laboratories plans to continue developing the technology to increase the variety of gases it can detect, and hopes to be able to incorporate such sensors into smartphone devices and wearable devices by 2018, with the aim of making breath component gas analysis as easy to perform as a temperature reading on a thermometer. The new sensor was presented at the 11th annual IEEE International Conference on Nano/Micro Engineered and Molecular Systems (IEEE-NEMS), held in Matsushima Town (Japan) during April 2016.

There are currently two major methods of analyzing breath gases. The first is gas chromatography, which can perform a detailed analysis of gas components, but the equipment is bulky and expensive, requires a trained operator, and takes several hours to produce results. The second is an “electronic nose” that contains numerous gas sensors. This method, while portable and fast, finds it difficult to distinguish between a target gas and other gases, and as such is not accurate to indicate health.

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