The Nose Knows

A variety of chronic diseases could soon be detected much earlier, while reducing the need for expensive and invasive testing, using a prototype “electronic nose.” The device utilizes CMOS integrated circuits to detect very low levels of chemicals in a person’s breath with an accuracy level that rivals blood tests.

Exhaled air contains information about many systems in the human body – from the blood as it circulates around the lungs to digestive gases in the stomach. The chemical makeup of these gases can be quantified with a technique known as rotational spectroscopy. Samples are exposed to electromagnetic waves over a wide range of frequencies which are selectively absorbed by specific compounds. By analyzing how the waves are attenuated the system can identify what chemicals are present and in what concentration. In some cases, the electronic nose has demonstrated greater specificity and sensitivity than breathalyzers, which have a hard time distinguishing acetone from ethanol, for example. This presents a problem for diabetics who typically exhibit high levels of acetone in their breath.

While breath analysis is not a new concept, the systems traditionally used are bulky and expensive. The use of CMOS technology will make the electronic nose much more affordable, and therefore, more widely available. The device will first be released for use in industrial applications, hospitals and clinics, however, it will very likely become available to consumers as the technology matures.