Scientists have developed the first guided catheter that moves like an insect through the arteries and blood vessels of the brain: the development could help treat difficult aneurysms.

An aneurysm is an abnormal tumor in the wall of a blood vessel. Blistering lesions appear on the cerebral artery, which can suddenly burst: the tumor affects more than 160 million people worldwide every year. About a quarter of patients cannot be treated, so it is very difficult to get to the tumor. As a result, patients are at risk of rupture and later death or long-term disability.

To heal a patient, neurosurgeons first insert wires into an artery near the groin and guide a catheter forward through the aorta and up towards the brain. The wires have a curved tip for intricate travel.

Unfortunately, many of the most important blood vessels we need to heal are very tortuous and fragile. Therefore, today, robotics is becoming essential to solve such medical problems.

James Friend, professor of medical engineering at the University of California
In order to create a controllable and dexterous catheter, scientists were inspired by beetles: their type of deformation and hydraulics during mating, the movement of their legs and flagella. As a result, scientists have created a soft robotic microcatheter with a hydraulic drive: it can move around the entire brain.

During development, the team first applied concentric layers of silicone on top of each other, each with a different hardness. The result is a silicone rubber catheter with a set of internal cavities, and at the end a harmless physiological fluid that can be controlled through a hand controller.

The authors tested a new catheter in a pig’s cerebral artery: the guided tip was visible on X-rays. Scientists plan to conduct a series of tests on animals, and then an operation on humans.