Scientists are developing a new way of carrying out internal examinations on patients - based on a wriggling worm.
These worms may help make the test more comfortable
In an endoscopy, a long flexible tube is fed into the body. It can be very uncomfortable.
But a team from the Scuola Superiore Sant'Anna, Pisa, found the ragworm, which lives in seashores, could offer a model for a more comfortable test.
They say their device would be able to "pull" itself along, rather than having to be forced into the body.
The team have developed a prototype device, named the Bioloch Ist, which imitates the undulating motion of the ragworm, also known as the paddleworm.
The worm, which is often used as fishing bait, moves in wet environments containing large amounts of solid and semi-solid material - similar to that often found inside the body.
The prototype consists of a simple worm with a flexible central spine and paddles sticking out either side along the worm's body.
The team are now working on a more advanced version of the device in which the paddles themselves can also move as well as the central spine.
Eventually, the device will be motorised.
The team are liaising with a biologist to work out the exact mechanisms for how the ragworm moves.
Paolo Dario, who led the research, said: "The basic concept is to develop a replacement for the current colonic endoscope, which is quite large and stiff, and has to be pushed inside a patient.
"If you can pull a device rather than push it, you can reduce the bending forces and so lessen the chance of damage to a patient's internal organs.
"We looked to nature for a model and chose the paddleworm because it is capable of 'swimming' with ease through relatively soft, unstructured environments."
He said the prototype was quite slow, taking 30 minutes to reach the end of the colon instead of the 10 minutes the conventional type takes.
But he said making the paddles move as well as the central spine of the device should help speed up the 'worm' endoscopy technique.
Professor Julian Vincent of the University of Bath, who also worked on the research, said the ragworms have a very different way of moving compared to earthworms.
He said: "The advantage from our point of view is that the paddle worm has a much greater variety of styles of moving, since it can remain straight and just move the paddles, wriggle and keep the paddles still, or wriggle and move the paddles as well.
"This gives more versatility in speed and general control. The paddle worm can also build burrows very rapidly.
"So the chances are that a robotic motor based on this design will be more versatile and faster than most others."
"Ultimately our idea is to turn the current ordeal of the colonic endoscopy procedure into something akin to a pleasurable experience!"