When things in our body go awry, through disease or infection, for example, the types of molecules in our breath can change. These variations have presented researchers around the world with a very real opportunity to detect various conditions, including lung cancer, with unprecedented ease. The latest scientists to start sniffing around this emerging form of medical diagnosis is a team from the University of Adelaide, who are developing a laser instrument inspired by dog's nose that can screen breath samples for signs of unrest.

The new system relies on a specialized laser and a technique called optical spectroscopy. This sees up to one million different light frequencies beamed through a sample of gas. As the different molecules absorb the light at different optical frequencies, the system is able to produce a unique molecular fingerprint for each sample. The team says this could provide for non-invasive, on-site breath tests for diseases such as diabetes, infections and certain types of cancers.

Dr James Anstie of the university's Institute for Photonics and Advanced Sensing, says they expect that over the next few months the system will approach part per million sensitivity, a measure that would place it somewhere between the sensitivity of a human and a dog.

This isn't the first time we've seen electronic breath analysis likened to the all-smelling power of a dog's nose. Since the 1980s reports have emerged detailing the ability of canines to detect cancer on the breath of their owners. These suspicions have since been confirmed by studies, giving rise to various research projects that look to replicate this ability of a dog's snout in practical scientific instruments.

The University of Adelaide team says their solution holds significant potential, as it will provide for nearly instantaneous results, high sensitivity and screen for a large range of different molecules at once. Anstie claims his team will have a working prototype in two to three years, with a market-ready product possibly available in three to five. The finished product may even be used to measure trace gases like atmospheric carbon dioxide or find impurities in natural gas.

"We now have a robust system to be able to detect the presence and concentrations of molecules in a sample," says Dr Anstie. "The next step is to work out how to accurately sample and interpret the levels which will naturally vary from person to person."

The research was published in the journal Optics Express, and Anstie talks about the technology in the video below.