Circuits on miniaturized ultrasound imaging system-on-a-chip: a review.

Trends of medical system move from a traditional in-person visit to virtual healthcare increases demands on point-of-care devices. Because ultrasound (US) is non-invasive, the demands highlight US imaging among other imaging modalities. Thanks to the development of US transducer technology, miniaturized US with application-specific integrated circuits (ASIC) have been researched. For example, applications that require small aperture sizes such as intravascular US (IVUS) and intra-cardiac echocardiography (ICE) require integration of system-on-a-chip (SoC) on the transducer. This paper reviews circuit techniques on the transmitter (TX) and receiver (RX) of the US imaging system. As TX circuits, pulser, T/RX switch, TX beamformer, and power management circuits are discussed. State-of-the-art transducer modeling, pre-amplifier, time-gain compensation, RX beamformer, quadrature sampler, and output driver are introduced as RX circuits.