Self-propelled catheter moves through bronchi like an earthworm

Japanese researchers have created a catheter that can navigate by itself through some of the thinnest branches of the bronchi.

Pulmonary lesions are biopsied to diagnose or treat respiratory illnesses like lung cancer. Bronchoscopy is the standard method for manual biopsies.

The bronchi branches into different directions and progressively gets thinner and more difficult to navigate. The propelling movement for catheters and endoscopes during traditional bronchoscopy makes it harder for doctors to reach troublesome lesions with biopsy forceps, which can result in false diagnostics.

Yuichiro Takai, professor in the department of respiratory medicine at Omori Medical Center at Toho University, and Hideyuki Tsukagoshi, a member of the department of system and control engineering at Tokyo Tech, developed a self-propelling catheter that creates traveling waves in multiple chambers by adding and reducing pressure inside a tube.

The catheter moves forward in a peristaltic motion that is similar to the way an earthworm moves. It can move through the small structures of the bronchi and can curve to choose the direction of propulsion. The researchers tested the catheter on a bronchus model.

The researchers hope to increase the accuracy of which way the catheter can be propelled. They also want to fit the catheter with a camera to be able to get information on the inside of the bronchi, create functions used for biopsies and treatment and give instruments a practical use.