Ultrasound wave based body area networks

Due to the rapid miniaturization of electronic circuits, tiny sensing and actuation devices can be built to aid in the diagnosis and treatment of major diseases. These devices, after being implanted or digested can continuously collect diagnostic information, and perform very localized fine-tuned medical treatments over extended periods of time. For a controlled operation of these devices, it is however crucial that they can reliably communicate with each other and with the outside world. This is however challenging with radio-frequency (RF) based communication technology, as RF waves do not propagate deep into the human tissue and pose serious health risks. This work targets the development of an alternative data transfer mechanism for electronic devices in and around the body through the use of ultrasound (US) waves. US has been used extensively for underwater communication as well as for medical imaging, and has demonstrated good conductance through the body. However, its use towards device to device communication in body area networks remains still largely unexplored.

Specifically, a finite impulse response (FIR) dataset of channel characterization experiments on scattering gelatin phantoms is published open-source at Github [Bos19_tbiocas]. Using these channel models, a custom OFDM modem is designed that obtains 340kbps at BER 1e-4 through a 10cm piece of beef tissue [Bos19_biocas]. Subsequently, the design is miniaturized in a dual ASIC solution featuring an end-to-end ASIC transceiver with a custom OFDM modem consuming 64 and 20.9 nJ/bit Tx/Rx [Bos22_biocas].