Robot pill that can be sent on missions inside body

Magnet-guided device can be swallowed to remove foreign objects in the stomach and gut

A ROBOT that can be swallowed in a pill and then sent on missions inside the body promises a revolution in internal treatment of the digestive system, scientists have claimed.

A team from the Massachusetts Institute of Technology (MIT), Sheffield University, and the Tokyo Institute of Technology trialled the fold-up device in a mock stomach and found it was able to dislodge and remove foreign objects such as batteries.

The researchers also believe the robot could be modified to deliver drugs and perform targeted surgery in otherwise inaccessible regions of the stomach and gut.

The device folds into a pill made of ice. When swallowed, the casing melts and the robot unfolds in the stomach.

Once extended, the robot rolls around the stomach lining by means of a “stick-slip” motion, controlled by magnetic fields outside the body.

The new technology is reminiscent of the 1966 science fiction film Fantas

tic Voyage, in which a submarine and its crew are shrunk to microscopic size in order to enter the body of an injured scientist and repair his brain.

Approximately 3,500 batteries are accidentally swallowed in the US each year, according to the research team.

While the batteries are frequently digested normally, if they come into prolonged contact with the tissue of the oesophagus or stomach they can cause an electric current that produces hydroxide and burns a hole in the tissue. Small and circular lithium batteries are a particular risk for small children, as they can easily be swallowed accidentally.

While the NHS holds no specific figures on the number of UK cases, swallowing batteries is known to have caused the deaths of some children.

In trials conducted by the MIT-led team, the robot rolled towards the lithium battery before attaching itself.

With the help of external magnets, the robot was then able to drag the battery away. The scientists say the robot, and any foreign objects it is removing, can leave the body by being dragged towards the gut where it can be passed naturally.

“It’s really exciting to see our small origami robots doing something with potential important applications to healthcare,” said Daniela Rus, professor of electrical engineering and computer science at MIT.

“For applications inside the body, we need a small, controllable, untethered robot system.

“It’s really difficult to control and place a robot inside the body if the robot is attached to a tether.”

Prof Rus said she was initially sceptical about the importance of ensuring the robot could remove batteries until Shuhei Miyashita, now a lecturer at York University, gave her a crude demonstration.

“Shuhei bought a piece of ham and he put the battery on it,” she said.

“Within half an hour the battery was fully submerged in the ham, so that made me realise that, yes, this is important. If you have a battery in your body, you really want it out as soon as possible.”

The robot is made from the same type of dried pig intestine used in sausage casings. Prof Rus said the ultimate aim was to develop sensors on the device so it could perform tasks automatically, without the need for an external controller.

Dr Miyashita said the next stage would be to test the origami robot in the stomachs of animals such as cows before moving on to human trials.

It is hoped that the device will be available for clinical use in six to eight years, he said.