A tiny worm-like robot has been developed to treat stroke patients by clearing blood vessel blockages and delivering drugs directly to the brain.

The 0.5mm-wide wire is driven through the body using magnetic fields which can be computer controlled from outside the room.

Although it hasn't yet been tested on a human patient, engineers have proved its functions on a miniature obstacle course and in a life-size model of the brain.

They hope it will one day be used to treat people with life-threatening bleeding or blockages in the brain and speed up therapy to save vital moments.

Scientists at the Massachusetts Institute of Technology in Boston developed the miniscule snake-like robot, which is a few centimetres long.

It's made of a flexible mix of nickel and titanium and coated with a lubricating hydrogel which helps it to slip through tight tubes without damaging tissue.