German company Satcon has come up with a high-tech way of ensuring that small children don’t get near working machinery without the driver knowing.

The solution involves the child wearing a small, hard-to-remove bracelet which sends out a signal that sounds an alarm in the cab of the tractor, combine or forager when the child gets within 100m of it.

Satcon says that German insurance companies plan to make it mandatory for all new tractors to be fitted with the unit by 2009 as a condition of getting cover. Cost at the moment is €1300 (£910) for the bracelet, receiver and two antennas but that could fall sharply if and when they are fitted as standard.