Ultrasound water-marking for simultaneous B-scan imaging and bio-telemetry

Abstract

Ultrasound imaging technology has undergone a revolution during the last decade due to the availability of transducers that can operate over a large range of frequencies, and also due to the availability of high-speed, high-resolution analog-to-digital converters and signal processors. The large data acquisition and computational bandwidth afforded on these portable and bench-top ultrasound imaging systems could potentially be leveraged for designing energy-efficient bio-telemetry links that can be used for communicating with devices implanted in vivo. In this paper, we discuss an ultrasound water-marking approach that can be used for simultaneous imaging and bio-telemetry. The trade-off involves supporting a reasonable data-rate bio-telemetry link and at the same time minimizing artifacts due to bio-telemetry data in the B-scan images. Specifically, we exploit a variance-based signal representation where the image background noise is modulated to encode the data to be transmitted or sensed. Using a B-scan ultrasound imaging system and a phantom setup we show that the approach can support biotelemetry links at sub-nanowatt transmission power and at depths greater than 10 cm.