Engineers have shown it is technically possible to guide a tiny robotic capsule inside the colon to take micro-ultrasound images, and this discovery could put an end to invasive endoscopy examinations.

Currently endoscopes - long, thin, flexible tubes equipped with a light and camera - are used to relay images from inside the body onto a screen. They help remove growths and find diseases and cancers that affect the upper part of the digestive system. The procedure is often uncomfortable, as the instrument is inserted down the throat or through the anus and is hooked up to a cable.

This new device, called Sonopill is a small capsule - with a diameter of 21mm and length of 39mm, which the engineers say can be scaled down. The capsule houses a micro ultrasound transducer, an LED light, camera and magnet.A very small flexible cable is tethered to the capsule which also passes into the body via the rectum and sends ultrasound images back to a computer in the examination room.

Sonopill is wirelessly guided through the colon using an outer body magnet and artificial intelligence. The patient first swallows the capsule before it transmits live images from the inside of the stomach and digestive system. The capsule is the size of a large pill and leaves your body naturally when you go to the toilet.

A team of scientists from England, Scotland, the US and Canada have successfully trialled the gadget on live animals.

The consortium has developed a technique called intelligent magnetic manipulation. Based on the principle that magnets can attract and repel one another, a series of magnets on a robotic arm that passes over the patient interacts with a magnet inside the capsule, gently manoeuvring it through the colon.

The magnetic forces used are harmless and can pass through human tissue, doing away with the need for a physical connection between the robotic arm and the capsule.

An artificial intelligence system (AI) ensures the smooth capsule can position itself correctly against the gut wall to get the best quality micro-ultrasound images. The feasibility study also showed should the capsule get dislodged, the AI system can navigate it back to the required location.

The authors said: 'Diseases of the gastrointestinal (GI) tract are numerous and severe, accounting for about eight million deaths annually worldwide.

'They include cancers and inflammatory bowel disease. Diagnosis and management of GI diseases are typically performed using optical flexible endoscopy.

'This is the current gold standard despite numerous drawbacks and very few design improvements since its introduction.

'We investigated and showed the feasibility of closed loop magnetic control using digitized micro-ultrasound feedback; this is crucial for obtaining robust imaging in an unknown and unconstrained environment.'

"We hope that in the near future, the Sonopill will be available to all patients as part of regular medical check-ups, effectively catching serious diseases at an early stage and monitoring the health of everyone's digestive system

The study is published in the Science Robotics journal.