Wireless Power and DATA Transfer to Deeply-Embedded Biosensors in Human Body

The process of transmitting power from one node to another via physical links without using wires is denoted as wireless power transfer (WPT). WPT plays an important role in medical applications for it offers the possibility of avoiding surgical operations during the replacement of embedded batteries in human body. In this paper, a WPT system for transferring power and DATA to deeply embedded biosensors is proposed. The system is designed such that it is capable of powering a biosensor simultaneously with DATA transmission from a transmitting coil located outside the human body at a distance of 100mm from the biosensor node. The simulation results have revealed the reception of a regulated DC voltage at the biosensor node of 1.2V, which is sufficient to charge a rechargeable embedded battery with an average DC current of 1.1mA. The results also reveal that the proposed system has succeeded in the extraction of the transmitted DATA at the biosensor side within a time of 30µs. The transmitter of the proposed WPT system is driven by a Class-E power source, which has accomplished a drain efficiency of 72% at an overall operating power of 6W. The proposed system is designed and verified on PSpice.