ABSTRACT
An ultrasound wave is a longitudinal wave in which oscillations are in the same direction as propagation. In addition, the ultrasound wave is attenuated as it propagates through the medium. This chapter explains the ultrasound imaging fundamentals and system considerations for developing a portable high-frequency ultrasound imaging system. It introduces the Penn State portable ultrasound imaging system as an example of existing portable high-frequency ultrasound imaging systems. The Penn State ultrasound imaging system consists of a low-voltage-operated thin-film transducer array and a fully integrated custom-designed complementary metal-oxide-semiconductor (CMOS) transceiver chip. The chapter outlines the key points of ultrasound imaging fundamentals: ultrasound physics, the basics of B-mode ultrasound imaging, and beamforming architectures. It describes the design specifications and details of the circuit components on the transceiver chip. The Penn State ultrasound imaging system integrates the complete ultrasound front-end electronics onto a single integrated circuit (IC) chip with closed-coupled thin-film ultrasound transducers, and then constructs high-resolution ultrasound images.
