  Methods for digital, phase-coherent acoustic communication date to at least
the work of Stojanjovic, et al [20], and the added robustness afforded by
improved phase tracking and compensation of Johnson, et al [21]. This work
explores the use of such methods for communications through tissue for
potential biomedical applications, using the tremendous bandwidth available in
commercial medical ultrasound transducers. While long-range ocean acoustic
experiments have been at rates of under 100kbps, typically on the order of 1-
10kbps, data rates in excess of 120Mb/s have been achieved over cm-scale
distances in ultrasonic testbeds [19]. This paper describes experimental
transmission of digital communication signals through samples of real pork
tissue and beef liver, achieving data rates of 20-30Mbps, demonstrating the
possibility of real-time video-rate data transmission through tissue for inbody
ultrasonic communications with implanted medical devices.
