Remote powering systems of medical implants for maintenance free healthcare applications

For favorable health care sensor devices especially long term monitoring sensors have to be completely imperceptible and maintenance free. A solution on these requirements is an implantable sensor system. The permittivity of body tissue and the desired distance to a remote station confronts the technology with several challenges. To avoid compromises and to be able to optimize both, communication and remote energy supply, we defined a novel concept and split frequency ranges. With the provided system energy can be rectified at 13.56 MHz from a remote station. Its powering level is 10mW. To store the energy a buffering concept is calculated based on a capacitor of about 4μF. To harvest energy for 0.2 s is enough to supply low power sensor devices and a MICS-Band transmitter for communication at 402 MHz-405 MHz. The active time of the implanted transmitter is in the range of 5ms with a transmission power of approximately 25μW.