Research And Hardware Design Of Digital Scanning Converter For Medical Ultrasound Imaging

To diagnose disease of the alimentary canal, changes of mucous membrane suffice fail to provide sufficient information to make out an objective diagnosis of the pathological changes. However, Endoscopic Ultrasonography System (EUS) can help obtain clear and accurate ultrasonic tomography images, and thus provide objective and sufficient information for diagnosis and therapy; In addition, compared to other imaging methods, the ultrasonic imaging are non-invasive, free of ionization and radiation, good at repeatability.The coordinate conversion is an important procedure to develop the EUS. In the B-mode sector scan ultrasonic imaging system, the raw image is in polar coordinates, therefore, it is main tasks of image pre-processing to achieve image coordinate transform and interpolation.This paper mainly introduces the design of Digital Scanning Converte(rDSC)for Medical Endoscopic Ultrasound Imaging. Using CORDIC arithmetic and look-up table complete coordinate conversion ,increase the speed of. ultrasonic scanning imaging. In the design, SRAM as the memorizers to store the images without DSC; FLASH as the look-up table; FPGA is used as the kernel module to control the data transferring, related circuits and relevant chips'working and accomplish data preprocessing. With the advantages of simple structure, nice flexibility and convenience, it satisfies the demand for real-time displaying in this system. To achieve the real-time feature, the spatial computation ability of FPGA is fully explored to enhance the parallel, pipelined computing. Based on FPGA and Verilog HDL, the proposed algorithms are complied and verified. The experimental result prove that the proposed algorithms can achieve satisfying image quality and real-time feature.This system uses ultrasonic video with image size of 512×512 and frame frequency of 15Hz. The time delay between image input and output is a frame cycle or around 67ms, so that it is a real-time process. In the end, features of the whole system are summarized and further work for improvement is indicated.