"Up to a third of the 25 million intravenous injections carried out in Britain each year fail first time, often because doctors and nurses push the needle straight through the vein without noticing, researchers said.
But the problem could be solved by a newly designed syringe which automatically detects when it enters a vein and prevents the needle from travelling any further.
Upon passing through the wall of a vein, the change in pressure activates a spring which forces the needle to instantly withdraw itself.
The needle is housed within a plastic tube, which remains in the vein and allows the drug inside the syringe to enter the blood stream.
Researchers from Nottingham Trent University, who designed the system, and Olberon medical Innovations, the medical equipment manufacturer, said the self-retracting needle could be produced for the same price as traditional needles..."