Controlling a Gut Bot's Position
Researchers have created a robot that can tour your gut.
August 1, 2008 — -- For the past few years, medical researchers have been trying to develop ways to peer painlessly inside the human body, from a swallowable sensor to a magnetically controlled image-snapping capsule. Now, a group at Carnegie Mellon University (CMU) has shown that a tiny capsule robot is adhesive enough to anchor inside an intestine and yet gentle enough not to tear soft tissue.
The anchoring robot would be swallowed like a normal pill and move through the body until it reached the gut. Then a doctor, using a wireless control, would tell the robot when to expand its legs and anchor. It would be good not only for snapping images, but also potentially for biopsies, drug delivery, heat treatment, and other treatment applications.
While doctors have, for the past several years, used a camera pill that transmits images of the intestines, being able to control the movement of such a device would have many benefits, says Mark Schattner, a gastroenterologist at the Memorial Sloan-Kettering Cancer Center, who was not involved in the work. "The number-one use would be biopsy," says Schattner. "The other would be control of bleeding--if you could cauterize or laser a source of bleeding, that would be [a] major therapeutic use." While the CMU robot is not yet ready for such uses, its ability to securely and safely anchor in the body is the first step in achieving more-advanced applications.
The trick to making the robot was finding an adhesive that would "stick repeatedly to tissues like intestines, esophagus, stomach, heart, and kidney surfaces," says Metin Sitti, a professor and principal investigator of the NanoRobotics Lab at CMU. Although strong biomedical adhesives exist, they stick once and cannot be removed. Other attempts to create removable adhesives utilized clamps and hooks, which could potentially damage tissue. By developing a strong adhesive that can attach and reattach many times, Sitti hopes to build a robot that can actually crawl inside the human body for therapeutic purposes without causing harm.