Electrical engineers at Stanford built a cardiac device that uses a combination of inductive and radiative transmission of power, at about 1.7 billion cycles per second, to its coiled receiving antenna.
The setup consisted of a radar emitter made out of one coffee can and a second can with a couple of LEDs attached to serve as a tethered receiver antenna.
Second, the delivery method is outdated and the extra hardware, including a special antenna, and design requirements increase production costs for little return in value.