Someday soon Cameron Riviere hopes thousands of his little robots will be crawling on patients' hearts delivering treatments that currently can only be done with massively invasive operations, if at all.

Riviere, an associate research professor at Carnegie Mellon University's Robotics Institute in Pittsburgh, isn't trying to remake the submarine from Fantastic Voyage. His inch-long HeartLander isn't small enough to navigate blood vessels.

Still, there are echoes of the science-fiction classic in Riviere's HeartLander robot, which is designed to crawl like an inchworm on the outer surface of a patient's heart. Prototypes have successfully delivered injections and even attached pacemaker leads in living pigs.

The device is inserted through a small incision in the chest and controlled with a wire tether by an external operator. Two suction-pad feet and a flexible midsection enable the device to move at about half a foot a minute.

"It is not completely independent or detached, but can freely move with the beating heart," Riviere said.

Just 6 millimeters high and 8 wide, the robot can squeeze into the space between the heart and its outer lining. Tiny holes on the feet create a vacuum that ensures HeartLander remains attached.

Riviere said he expected the device would be particularly useful for delivering medications under development that require precisely placed injections not now possible because of the movement of a beating heart.

"Since you have this suction that is holding onto the heart, it is actually beating with the heart" and can make precise injections, he said.

- Josh Goldstein