To give early-warning wireless readings of heart attacks, scientists have created a microchip, which can be implanted under the skin.
The device - just 1.4cm long - can check up to five different substances in the blood around the clock - and send the results to a doctor's computer.
The inventors claim that the tiny "lab-on-a-chip" can be used to give an early warning of a heart attack, or monitor cancer patients undergoing chemotherapy.
Giovanni de Micheli of the Ecole Polytechnique Federale de Lausanne told Sky News that the chip can be "programmed" by coating it with chemicals that react with substances that doctors want to monitor.
He said that the chip comes in contact with fluids in the body and the sensors react to the presence of particular compounds in the fluids and send the data outside.
A patch on the surface of the skin powers the chip and sends the data via Bluetooth to a smartphone or a tablet, which then relays it on to the doctor.