The electronic noses basically consist of a bunch of gas sensors which sample and analyze inhaled and exhaled air. And based on initial testing, they're rather accurate:
In a test involving 14 people, the electronic nose proved to be 87.5 percent accurate, compared to conventional tests like fraction of exhaled nitric oxide (FeNO) and lung function tests, which were 79.2 percent and 70.8 percent accurate respectively.
Now if only they can combine combine these asthma detectors with breathalyzers then every horrid driver could get a free medical exam before being handcuffed.
[Gizmodo via Science Daily via Inhabitat]