Research On Medical B-Mode Ultrasonic Imaging Front-End System

Medical ultrasound imaging is a technology that ultrasound is used as the carriers to detect the inner part of the living creatures. Combining the digital signal processing and image processing techniques as well as the computer technique, the medical ultrasound imaging can extract the effective echo signals for imaging of tissues and organs.To make sure that the doctors can have better accurate of diagnosis, the quality of organ-image is one of the key factors, as well as the better treatment for patients. High-resolution image is no longer impossible since more and more techniques such as the computer technique, microelectronic technique and other new approaches were applied in the field of medical ultrasound imaging. Thereafter, in this paper, we aim at presenting the research of some techniques on phased array scanning, digital beam-forming and digital signal processing systems. Although this research is based on a semi-analog semi-digital portable B-ultrasonic device, the contribution can be extended further for the development of digitalization and miniaturization in B-ultrasonic devices.First, a FPGA-based B-mode ultrasound imaging front-end system is presented by combining the principle of ultrasonic pulse-echo imaging and design specifications, as well as its principle and hardware structures. Moreover, the general framework and the sub-modules of digital beam-former are described according to the principle of phased array scanning and digital beam-forming. Then the whole design is implemented on an Altera EP3C16Q240C8N FPGA. Finally, a discussion of quadrature demodulation, dynamic filtering and logarithmic compression is presented. The major technique, namely the quadrature demodulation is presented and implemented by Matlab. The results show that the proposed approach is feasible.