Follow your nose

Une invention qui a du nez.

Hippocrates, the father of medicine, was known to have used smell as an aid to his work. Generations of doctors followed suit. Syphilis, for instance, is thought to have a characteristic odour; the smell of rotting apples suggests diabetes. Today, things are more sophisticated. All sorts of volatile organic compounds (gases, known as VOCs) have been identified, in laboratories, as markers of specific diseases from breast cancer to cholera. But despite all this knowledge, a “breathalyser for disease” has stubbornly failed to materialise.

2.The barrier, as so often with new diagnostic tools, is not whether such things are technically possible, but whether they can be proven to work reliably and usefully when used by doctors. Owlstone Medical, based in Cambridge, thinks it has developed just such a gadget. Its breath analyser is the subject of several big trials. One is recruiting 4,000 patients across Europe to develop a test for the early detection of lung cancer—a disease that is often diagnosed too late to treat. Another is attempting the detection of early-stage colorectal cancer in 1,400 people.

3.One reason Owlstone’s device has generated such interest is that it has a documented record. The basic technology has been in use for many years, detecting chemical warfare agents for military customers. In the medical version, breath is exhaled across a sensor which ionises the VOCs, causing them to gain an electric charge. The molecules are then sorted according to how fast they move through an oscillating electric field. The result is a chemical fingerprint, or “breath biopsy”.

4.If the trials are successful, the benefits could be big. Widespread screening could help spot many diseases whose symptoms take time to develop. Breath biopsies are cheap, and free of risk. If they can prove their worth, they will be a breath of fresh air for diagnostics.

The result is a chemical fingerprint, or "breath biopsy."