Miniature sensors similar to those that trigger airbags in cars might soon be implanted in the hearts of people suffering from a kind of heart disease. The sensors would make it easy for doctors to measure blood pressure inside the heart, which at present involves repeated operations.
The implant, the size of a grain of rice, is one of a new breed of medical devices that requires no batteries. A radio transmitter and receiver held near the body provides the power and interrogates the implant.
The device is designed for people with congestive heart failure, where fluid builds up in organs and limbs because the heart fails to pump enough blood around the body. There are now more than half a million new cases each year in the US alone.