How many pacemakers can fit on the head of a pin? Just one. But that’s pretty impressive if you think about it.

At Stanford University, a team of researchers has built a tiny, implantable cardiac device that measured less than a millimeter in radius. This proof-of-concept device (which didn’t actually set the pace for the contraction of living heart muscles) could be so small because it didn’t require batteries—instead, it was powered by radio waves transmitted from outside the body.

Lead researcher Ada Poon, an assistant professor of electrical engineering at Stanford, thinks that wireless power transfer could lead to smaller and more precise implantable medical devices, as well as swallow-able devices. For cardiac devices, wireless power could offer big improvements over pacemakers powered by bulky batteries that need to be replaced periodically via surgery. [read more..]