First Step Towards a Fully-Miniaturized Intra-body Communication Transceiver Based on Galvanic Coupling

With the growing interest in wireless medical implants, efficient and secure intra-body communication becomes mandatory. A promising technique is the Galvanic Coupling (GC) communication. This research area is in constant evolution but despite this, currently there is no complete miniaturized transceiver architecture solution proposed in the literature. In this paper, we present the first fully-miniaturized GC transceiver architecture based on off-the-shelf components considering implantability constrains such as size and power consumption. The transmitter consists of a micro-controller, a Direct Digital Synthesizer (DDS) for analog sine wave generation and an amplifier. The receiver is made of a two-stage analog amplification chain. The first stage is a instrumentation amplifier and the second stage is made of a operational amplifier (Op Amp). Two versions of the receiver has been designed with two instrumentation amplifiers. The design has been tested using a phantom, in a on-body to on-body and an implanted to implanted configurations. The proposed architecture is a compromise between implantation constraints (components area of 0.75 cm $$^2$$ and maximum consumption 18 mA) and maximum transmission frequency (800 kHz). The intra-body communication has been validated for various distances (up to 60 cm), four different electrodes relative orientations and in different settings (on body and intra-body).