Researchers at Stanford have developed a tiny wireless implant device.

Radio waves reflected by these antennas slow down in frequency while they accelerate when reflected by antennas that relax when not under pressure. The research team, led by Chemical Engineering Professor Zhenan Bao, demonstrated the device by first recording the pulse of a team member without touching him and also by monitoring the pressure inside the skull of a lab mouse.
“The device we invented here is extremely easy to manufacture and consumes no energy until readings are being made. In the short term we hope to use devices like this to track packages and monitor health conditions. In the longer run we dream of using this technology to create touch-sensitive lining for prosthetic devices”, Bao said.
Source-Medindia