This is a pretty amazing robot, "HeartLander is a miniature mobile robot that delivers minimally invasive therapy to the surface of the beating heart" - this quote is taken from the HeartLander web page.

Heartlander was designed at The Robotics Institute at Carnegie Mellon. The Heartlander lists the major media coverage for this robot, the New York Times has a really good diagram showing the Heartlander and explaining how it works - the HeartLander "uses suction to adhere to a beating heart. Moving like an inchworm, it can reach areas that now require doctors to deflate a patients lungs".

There are some really impressive video's as well - amazing that something so small can be controlled like this to make surgery less invasive.