In this paper, we demonstrate the use of wireless acoustic communications through the human body, in-vivo. The acoustic communications signals are intended to be used for fixed in-vivo biomedical devices. In-vivo biomedical devices include, for example, pacemakers, but more importantly, neural implants. The use of acoustic communications for neural implants represents a significant improvement as wired and wireless RF communications cannot be utilised. The acoustic communications channel comprises of a piezoelectric transducer as the transmitter, a section of the human body as the transmission medium, and a second piezoelectric transducer as the receiver. In this initial work, a forearm was used as the transmission medium. Communicating acoustically through the human body was successfully achieved. We present results showing the performance of the acoustic communications channel. The frequency response, transfer function and transient response (at resonance) of the communications channel were measured. Due to the frequency response of the communications channel, phase shift keying was chosen as the digital modulation method. Sample communications signals are included. For comparison, amplitude shift keying results are also shown. The results suggest that a data rate of over 10kbps could be achieved with the configuration used.

Date Published: 30 December 2008
PDF: 10 pages
Proc. SPIE 7270, Biomedical Applications of Micro- and Nanoengineering IV and Complex Systems, 72700T (30 December 2008); doi: 10.1117/12.814422

Published in SPIE Proceedings Vol. 7270:
Biomedical Applications of Micro- and Nanoengineering IV and Complex Systems
Dan V. Nicolau; Guy Metcalfe, Editor(s)