The Double check

Simple solutions are most often the best. A double-barrelled syringe could prevent blood samples from becoming contaminated with skin bacteria, thereby giving wrong test results. To test for blood infections, the sample is drawn from the vein. Ideally, the skin-punctured site should be thoroughly sterilised. But as this takes up to two minutes, the process is often cut short, resulting in contamination of six per cent of the six million blood cultures performed every year in the us alone.

The solution, dreamed up by microbiologist-turned-inventor Juan Walterspiel of the US, consists of a miniature syringe and a standard-sized syringe attached to a single needle by a y-shaped connector. Once the needle is introduced into the vein, the first millilitre of blood -- the portion most likely to carry contaminants -- is drawn into the smaller syringe. Then the rest is drawn into the main syringe and used for tests.