Tadpole endoscope offers new hope for gastrointestinal cancer detection

The problem of looking at the inside of the body is a pressing one for doctors, and one particularly difficult issue is the gastrointestinal tract. Cancers in this system — the oesophagus, stomach, intestines and rectum — are major causes of death and difficult to investigate, because two of the most useful diagnostic methods for looking inside the tract and extracting samples: gastroscopy, where a camera on a flexible probe is inserted down the throat; and endoscopy,  where a similar system goes in the other end — are so unpleasant and traumatic for the patient. But help might be at hand, thanks to the humble tadpole.

The idea of placing a camera in a swallowable capsule that can navigate its own path through the digestive tract and send pictures back to doctors isn’t a new one: indeed, so-called capsule endoscopy currently the best way to get pictures of the intestines between the stomach and colorectal system, the boundary zone between gastroscopy and endoscopy. But it isn’t without drawbacks: The speed of transport through the system, from muscular ripples along the intestines called peristalsis can vary widely from person to person; it can be difficult to determine precisely where lesions and growths are, because of mismatches between imaging speed and peristalsis, which can also lead to unclear images; and in the parts of the system where the capsule is free to tumble, it can sometimes be pointing in the wrong direction to provide a picture of a site of concern.