E-nose- we can sniffing out disease one day

The electronic nose in an instrument that attempts to mimic the human olfactory system. Humans and animals don't identify specific chemicals within odours; what they do is to recognise a smell based on a response pattern. You, as a human, will smell a strawberry and say "that's a strawberry". If you gave this to a traditional analytical piece of equipment, it might tell you what the 60-odd chemicals in the odour were - but that wouldn't tell you that it was a strawberry.

A traditional electronic nose has an array of chemical sensors, designed either to detect gases or vapours. These sensors are not tuned to a single chemical, but detect families of chemicals - [for example] alcohols. Each one of these sensors is different, so when they are presented to a complex odour formed of many chemicals, each sensor responds differently to that odour. This creates a pattern of sensor responses, which the machine can be taught to recognise.

A dog is very, very sensitive. Special research teams work on training dogs to detect cancers as you would do explosives. What we are trying to do with the electronic nose is create an artificial means of replicating what the dog does. Such machines have the advantage that they don't get tired, will work all day and you only need to feed them electricity.

If there is an easy test that can be done for 5p, for example, like a dipstick test, then there is very little point in using an electronic nose as it is unlikely to save the NHS money and time. Where it is best applied is for the diagnosis of conditions where current tests are either expensive, not sufficiently sensitive or do not provide a means to rapidly diagnose. One example could be in screening for colorectal cancer, where current tests are only 40% accurate and people don't like using stool samples.

There are a few products on the market and these are fairly recent. The potential for this technology has been known for more than 20 years but what is happening now is that the sensor technology is starting to catch up with these aspirations. I think that you'll see - probably in the next five years.

Though I see electronic nose technology being used in both primary and secondary care, the future could well be in personalised healthcare, to provide a non-invasive means of diagnosing and monitoring heath. The other key area is going to be for use in developing countries -it has already been shown that you can detect TB with these instruments on the breath, so the opportunities for a spectrum of disease detection is vast.